94 research outputs found
Towards Scalable 3D Anomaly Detection and Localization: A Benchmark via 3D Anomaly Synthesis and A Self-Supervised Learning Network
Recently, 3D anomaly detection, a crucial problem involving fine-grained
geometry discrimination, is getting more attention. However, the lack of
abundant real 3D anomaly data limits the scalability of current models. To
enable scalable anomaly data collection, we propose a 3D anomaly synthesis
pipeline to adapt existing large-scale 3Dmodels for 3D anomaly detection.
Specifically, we construct a synthetic dataset, i.e., Anomaly-ShapeNet, basedon
ShapeNet. Anomaly-ShapeNet consists of 1600 point cloud samples under 40
categories, which provides a rich and varied collection of data, enabling
efficient training and enhancing adaptability to industrial scenarios.
Meanwhile,to enable scalable representation learning for 3D anomaly
localization, we propose a self-supervised method, i.e., Iterative Mask
Reconstruction Network (IMRNet). During training, we propose a geometry-aware
sample module to preserve potentially anomalous local regions during point
cloud down-sampling. Then, we randomly mask out point patches and sent the
visible patches to a transformer for reconstruction-based self-supervision.
During testing, the point cloud repeatedly goes through the Mask Reconstruction
Network, with each iteration's output becoming the next input. By merging and
contrasting the final reconstructed point cloud with the initial input, our
method successfully locates anomalies. Experiments show that IMRNet outperforms
previous state-of-the-art methods, achieving 66.1% in I-AUC on Anomaly-ShapeNet
dataset and 72.5% in I-AUC on Real3D-AD dataset. Our dataset will be released
at https://github.com/Chopper-233/Anomaly-ShapeNe
Microbiome-derived bile acids contribute to elevated antigenic response and bone erosion in rheumatoid arthritis
Rheumatoid arthritis (RA) is a chronic, disabling and incurable autoimmune
disease. It has been widely recognized that gut microbial dysbiosis is an
important contributor to the pathogenesis of RA, although distinct alterations
in microbiota have been associated with this disease. Yet, the metabolites that
mediate the impacts of the gut microbiome on RA are less well understood. Here,
with microbial profiling and non-targeted metabolomics, we revealed profound
yet diverse perturbation of the gut microbiome and metabolome in RA patients in
a discovery set. In the Bacteroides-dominated RA patients, differentiation of
gut microbiome resulted in distinct bile acid profiles compared to healthy
subjects. Predominated Bacteroides species expressing BSH and 7a-HSDH
increased, leading to elevated secondary bile acid production in this subgroup
of RA patients. Reduced serum fibroblast growth factor-19 and dysregulated bile
acids were evidence of impaired farnesoid X receptor-mediated signaling in the
patients. This gut microbiota-bile acid axis was correlated to ACPA. The
patients from the validation sets demonstrated that ACPA-positive patients have
more abundant bacteria expressing BSH and 7a-HSDH but less Clostridium scindens
expressing 7a-dehydroxylation enzymes, together with dysregulated microbial
bile acid metabolism and more severe bone erosion than ACPA-negative ones.
Mediation analyses revealed putative causal relationships between the gut
microbiome, bile acids, and ACPA-positive RA, supporting a potential causal
effect of Bacteroides species in increasing levels of ACPA and bone erosion
mediated via disturbing bile acid metabolism. These results provide insights
into the role of gut dysbiosis in RA in a manifestation-specific manner, as
well as the functions of bile acids in this gut-joint axis, which may be a
potential intervention target for precisely controlling RA conditions.Comment: 38 pages, 6 figure
The establishment and application of a dual Nano-PCR detection method for feline calicivirus and feline herpesvirus type I
Feline calicivirus (FCV) and Feline herpesvirus type I (FHV-I) are the main pathogens causing upper respiratory tract infections in cats, and some wild animals. These two viruses always coinfection and cause serious harm to pet industry and wild animals protection. Established a rapid and accurate differential diagnosis method is crucial for prevention and control of disease, however, the current main detection method for these two viruses, either is low sensitivity (immunochromatographic strip), or is time-consuming and cannot differential diagnosis (conventional single PCR). Nanoparticle-assisted polymerase chain reaction (Nano-PCR) is a recently developed technique for rapid detection method of virus and bacteria. In this study, we described a dual Nano-PCR assay through combining the nanotechnology and PCR technology, which for the clinical simultaneous detection of FCV and FHV-I and differential diagnosis of upper respiratory tract infections in cats or other animals. Under optimized conditions, the optimal annealing temperature for dual Nano-PCR was 51.5°C, and specificity test results showed it had no cross reactivity to related virus, such as feline panleukopenia virus (FPV), feline Infectious peritonitis virus (FIPV) and rabies virus (RABV). Furthermore, the detection limit of dual Nano-PCR for FCV and FHV-I both were 1 × 10−8 ng/μL, convert to number of copies of virus DNA was 6.22 × 103copies/μL (FCV) and 2.81 × 103copies/μL (FHV-I), respectively. The dual Nano-PCR detected result of 52 cat clinical samples, including ocular, nasal and faecal swabs, and (3 FCV-positive samples), was consistent with ordinary PCR and the clinical detection results. The dual Nano-PCR method established in this study with strong specificity and high sensitivity can be used for virus nucleic acid (FCV and FHV-I) detection of clinical samples of feline upper respiratory tract infections feline calicivirus and feline herpesvirus while providing support for the early diagnosis of cats that infected by FCV and FHV-I
Evaluation method of medical service system based on DEMATEL and the information entropy: A case study of hypertension diagnosis and treatment in China.
Precise and reasonable evaluation of the multi-attribute value of medical system is the basis for hospitals to implement total quality management. Excellent medical system is necessary as a part of modern urban governance. However, most of medical value evaluation work relies on scale and artificial scoring at present, lacking in objectivity. Therefore, a scientific and comprehensive medical value evaluation system is needed urgently to give full play to the guiding role of value evaluation and promote the improvement of the medical service system. In this study, DEMATEL and information entropy are used to quantify the degree of mutual influence between system indicators and the differences in medical market performance respectively, so as to obtain the objective index weight. Hypertension has the highest incidence in the whole chronic disease system, which seriously affects people's daily life. Based on the existing hypertension diagnosis and treatment index system, a comprehensive and objective evaluation model is established to evaluate the hypertension diagnosis and treatment behaviors of different medical institutions, which achieves good result. This method has effectively improved the relative deficiency of one-sided subjective evaluation and has a great guiding significance for the comparison of treatment in departments and the economical use of medical resources
Enzymatic calcification to solidify desert sands for sandstorm control
Sandstorms have been recognized as severe natural disasters worldwide and are increasingly occurring due to land desertification. In this study, an effective and environmentally friendly method (enzymatically induced calcite precipitation-polyvinyl acetate, EICP-PVAc) was proposed for sandstorm control. The technique was applied in a large-scale desert sand solidification experiment (50000 m2) to study the wind-erosion resistance of the technology in the Tengri desert. Due to the straw checkerboard barrier zone and the sand control belt with low barriers zone are easily buried by shifting sands. These engineering methods cannot be reset based on actual field status; so, they easily loss the function of sand proof. The EICP-PVAc method proposed for shifting sand solidification can adapt to the change of different terrain conditions and is suitable for shifting sands with changeable wind direction. After treatment, the straw checkerboard barriers zone and the sand control belt with low barriers zone had larger surface strengths, thicker cemented crust layers and larger CaCO3 contents. The surface strength increased exponentially with increasing thickness of crust layer. In addition, the network structure of PVAc not only increased the ability of solidifying sand stabilization to resist rain erosion, but also enhanced the intensity of sand stabilization. Therefore, the treatment ensured a long-term rainfall-erosion resistance. Moreover, the wind-erosion resistance of the treated area was significantly improved, and the desert sands in this area were not blown by wind in 60 days. The results demonstrated that EICP-PVAc treatment significantly controlled sandstorm, which presents promising potential for anti-desertification
Direct air CO2 capture using coal fly ash derived SBA-15 supported polyethylenimine
Designing an amine modified silica derived from coal fly ash (CFA) towards direct air CO2 capture (DAC) provides an economic way to manage increasing atmospheric CO2 concentration utilizing solid wastes. In this work, rod-like SBA-15 (SBA-15-R) and wheat-like SBA-15 (SBA-15-W) with distinct pore lengths are synthesized from CFA by controlling the synthesis conditions and then modified by PEI via the wet impregnation method. Their CO2 adsorption behaviors under sub-ambient conditions are investigated to explore their feasibility under aggressive conditions. The adsorbents with various silica morphologies exhibit distinctive CO2 adsorption performance under ambient and sub-ambient conditions. At 35°C under dry conditions, the CO2 adsorption capacity increases with amine loading. The CO2 adsorption capacity (qe) of SBA-15-W-PEI with long channels reaches the highest qe of 1.92 mmol/g with 70 wt.% PEI loading due to a large amount of strong chemisorption sites. Under the sub-ambient conditions (-20°C, 400 ppm), SBA-15-R-PEI30 with short channels having weaker CO2 diffusion resistance exhibits promising CO2 uptake of 0.83 mmol/g. These findings indicate that the ultra-dilute CO2 adsorption at ambient temperature requires an adsorbent with large amounts of adsorption sites, whereas the adsorbents for cold temperature application should reconcile amine loading with CO2 diffusion resistance inside pores. The co-adsorption of H2O and CO2 significantly improves CO2 capacity from 0.83 mmol/g and 1.92 mmol/g to 1.81 mmol/g and 3.48 mmol/g for SBA-15-R-PEI30 (-20°C, 400 ppm) and SBA-15-W-PEI70 (35°C, 400 ppm), respectively. Furthermore, the CFA derived SBA-15-PEI shows good cyclic stability during five consecutive TSA cycles. Preparing the amine silica adsorbents from coal fly ash potentially reduces the adsorbent cost of DAC devices. Moreover, the systematic exploration of amine silica adsorbents at a wide range of temperatures guides the design of high-performance CO2 adsorbents employed under various climatic conditions
3-D FEM simulation of lift-off effects on magnetic flux leakage testing
With the increase of pipelines and steel tanks, corrosion leakage accidents happen frequently. The magnetic flux leakage (MFL) method is currently the most commonly used pipeline inspection technique. In this paper, three-dimension (3-D) finite element analysis has been used to examine the effect of lift-off on MFL signals. Firstly, according to Maxwell equations, the 3-D MFL field distributions of defects were deduced. Then, the 3-D finite element simulation model of MFL under the vibration conditions was established in ANSYS and the MFL signals of defects at different lift-off were analyzed. To confirm the 3-D simulation results, a set of artificial defects was made and the MFL experiments were performed. Finally, the best lift-off at different sizes of defects was achieved by minimizing the errors caused by vibration and electromagnetic noise. This research can be used to optimize the detector structure to increase MFL detection measurement accuracy
An Orthogonal Type Two-Axis Lloyd’s Mirror for Holographic Fabrication of Two-Dimensional Planar Scale Gratings with Large Area
In this paper, an orthogonal type two-axis Lloyd’s mirror interference lithography technique was employed to fabricate two-dimensional planar scale gratings for surface encoder application. The two-axis Lloyd’s mirror interferometer is composed of a substrate and two reflective mirrors (X- and Y-mirrors), which are placed edge by edge perpendicularly. An expanded and collimated beam was divided into three beams by this interferometer, a direct beam and two reflected beams, projected onto the substrate, X- and Y-mirrors, respectively. The unexpected beam sections having twice reflected off the mirrors were blocked by a filter. The remaining two reflected beams interfered with the direct beam on the substrate, generating perpendicularly cross patterns thus forming two-dimensional scale gratings. However, the two reflected beams undesirably interfere with each other and generate a grating pattern along 45-degree direction against the two orthogonal direction, which influence the pattern uniformity. Though an undesired grating pattern can be eliminated by polarization modulation with introduction of waveplates, spatial configuration of waveplates inevitably downsized the eventual grating, which is a key parameter for grating interferometry application. For solving this problem, theoretical and experimental study was carefully carried out to evaluate the fabrication quality with and without polarization modulation. Two-dimensional scale gratings with a 1 μm period in X- and Y-directions were achieved by using the constructed experiment system with a 442 nm He-Cd laser source. Atomic force microscopy (AFM) images and the result of diffraction performances demonstrated that the orthogonal type two-axis Lloyd’s mirror interferometer can stand a small order undesired interference, that is, a degree of orthogonality between two reflected beams, denoted by γ, no larger than a nominal value of 0.1
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