Multi-site, Multi-domain Airway Tree Modeling (ATM'22): A Public Benchmark for Pulmonary Airway Segmentation

Open international challenges are becoming the de facto standard for assessing computer vision and image analysis algorithms. In recent years, new methods have extended the reach of pulmonary airway segmentation that is closer to the limit of image resolution. Since EXACT'09 pulmonary airway segmentation, limited effort has been directed to quantitative comparison of newly emerged algorithms driven by the maturity of deep learning based approaches and clinical drive for resolving finer details of distal airways for early intervention of pulmonary diseases. Thus far, public annotated datasets are extremely limited, hindering the development of data-driven methods and detailed performance evaluation of new algorithms. To provide a benchmark for the medical imaging community, we organized the Multi-site, Multi-domain Airway Tree Modeling (ATM'22), which was held as an official challenge event during the MICCAI 2022 conference. ATM'22 provides large-scale CT scans with detailed pulmonary airway annotation, including 500 CT scans (300 for training, 50 for validation, and 150 for testing). The dataset was collected from different sites and it further included a portion of noisy COVID-19 CTs with ground-glass opacity and consolidation. Twenty-three teams participated in the entire phase of the challenge and the algorithms for the top ten teams are reviewed in this paper. Quantitative and qualitative results revealed that deep learning models embedded with the topological continuity enhancement achieved superior performance in general. ATM'22 challenge holds as an open-call design, the training data and the gold standard evaluation are available upon successful registration via its homepage.Comment: 32 pages, 16 figures. Homepage: https://atm22.grand-challenge.org/. Submitte

A Supramolecular Photosensitizer System Based on Nano-Cu/ZIF-8 Capped with Water-Soluble Pillar[6]arene and Methylene Blue Host–Guest Complexations

Photodynamic therapy (PDT) as a safe, non-invasive modality for cancer therapy, in which the low oxygen and high glutathione in the tumor microenvironment reduces therapeutic efficiency. In order to overcome these problems, we prepared a supramolecular photosensitive system of O2-Cu/ZIF-8@ZIF-8@WP6–MB (OCZWM), which was loaded with oxygen to increase the oxygen concentration in the tumor microenvironment, and the Cu2+ in the system reacted with glutathione (GSH) to reduce the GSH concentration to generate Cu+. It is worth noting that the generated Cu+ can produce the Fenton reaction, thus realizing the combination therapy of PDT and chemodynamic therapy (CDT) to achieve the purpose of significantly improving the anti-cancer efficiency

Experimental study on deterioration of bedrock strength and P-wave velocity by pressurized seawater

Abstract Bedrock has to be excavated before the construction of rock-socketed pile foundations for offshore wind power turbines, leading to the exposure of fresh and dry rocks to seawater. The pile-rock interface is partially separated under the long-term action of various cyclic loads during the operation stage of offshore wind turbines, and the infusion of seawater will further weaken the bedrock. To comprehensively investigate the deterioration of bedrocks by pressurized seawater, tests on point load strength and slake durability were carried out to study the long-term deterioration of mechanical properties of granite, sandstone, and tuff collected from an offshore wind power farm. The elastic P-wave velocity was measured to analyze the variation trend of P-wave velocity, the mechanism of which was revealed by means of Gassmann’s equation. The results of mechanical experiments indicate that granite is almost impervious to pressurized seawater, while the mechanical properties of sandstone and tuff are deteriorated by water, especially by the pressurized seawater. After 60 days of immersion in seawater at 0.5 MPa pressure, decreasing amplitude of point load strength and slake durability index for the sandstone specimens in seawater reaches 53.2% and 18.5%, respectively, and that for the tuff specimens is 14.6% and 1.52%, respectively. The elastic P-wave velocity of granite shows an upward trend with increasing immersion time in different environments, but there exists a different tendency between the P-wave velocity of sandstone and tuff specimens in water or seawater with normal pressure and that in seawater with 0.5 MPa pressure. The variation of P-wave velocity of different types of rocks is studied based on Gassmann’s equation that takes into account the change of saturation degree, porosity, and compressibility of the matrix material

Highly selective and sensitive xylene sensors based on Nb-doped NiO nanosheets

It's demonstrated that doping of aliovalent atom can greatly influence the sensing performance of metal oxides-based gas sensors. In this work, Nb-doped nickel oxides with Nb contents in the range of 6.2-29.1 at% have been synthesized by a one-step hydrothermal method. The gas sensing test results indicates that the 20.2 at% Nb doped NiO possesses an ultrahigh response (335.1-100 ppm), excellent selectivity and theoretical ppb-level detection limit (2 ppb) to xylene at 370 degrees C, which is much better than that of pure NiO sensor. The higher specific surface area and the enhanced catalytic activity caused by higher ratio Ni3+/Ni2+ are considered as the main reasons for the enhanced gas sensor performance

Simulation Study on the Effect of Forced Ventilation in Tunnel under Single-Head Drilling and Blasting

Based on the excavation of Yuelongmen tunnel on ChengLan Railway in China, this paper will probe into the forced ventilation effect of harmful gas generated by drilling and blasting construction, simulate the diffusion process of harmful gas generated during blasting operation on the tunnel face by establishing the finite element model of gas turbulent flow and concentration diffusion in the tunnel, and study the spatial-temporal evolution law of CO concentration field under different air pipe layout locations and tunnel excavation methods. The results show that, compared with corner layout, haunch layout, and central layout, the ventilation effect is the best when the air pipes are arranged near the wall at the tunnel vault, and the CO concentration can be reduced to the concentration limit after 588 s of ventilation; compared with the full-face tunneling method and the lower pilot heading method, the benching tunneling method can effectively reduce the retention time of CO near the tunnel face, and the CO concentration on the tunnel face can be reduced to the standard limit after 326 s of ventilation near the wall of tunnel vault

CoFlux:Robustly Correlating KPIs by Fluctuations for Service Troubleshooting

Internet-based service companies monitor a large number of KPIs (Key Performance Indicators) to ensure their service quality and reliability. Correlating KPIs by fluctuations reveals interactions between KPIs under anomalous situations and can be extremely useful for service troubleshooting. However, such a KPI flux-correlation has been little studied so far in the domain of Internet service operations management. A major challenge is how to automatically and accurately separate fluctuations from normal variations in KPIs with different structural characteristics (such as seasonal, trend and stationary) for a large number of KPIs. In this paper, we propose CoFlux, an unsupervised approach, to automatically (without manual selection of algorithm fitting and parameter tuning) determine whether two KPIs are correlated by fluctuations, in what temporal order they fluctuate, and whether they fluctuate in the same direction. CoFlux's robust feature engineering and robust correlation score computation enable it to work well against the diverse KPI characteristics. Our extensive experiments have demonstrated that CoFlux achieves the best Fl-Scores of 0.84 (0.90),0.92 (0.95), 0.95 (0.99), in answering these three questions, in the two real datasets from a top global Internet company, respectively. Moreover, we showed that CoFlux is effective in assisting service troubleshooting through the applications of alert compression, recommending Top N causes, and constructing fluctuation propagation chains

Cartography of opportunistic pathogens and antibiotic resistance genes in a tertiary hospital environment

Although disinfection is key to infection control, the colonization patterns and resistomes of hospital-environment microbes remain underexplored. We report the first extensive genomic characterization of microbiomes, pathogens and antibiotic resistance cassettes in a tertiary-care hospital, from repeated sampling (up to 1.5 years apart) of 179 sites associated with 45 beds. Deep shotgun metagenomics unveiled distinct ecological niches of microbes and antibiotic resistance genes characterized by biofilm-forming and human-microbiome-influenced environments with corresponding patterns of spatiotemporal divergence. Quasi-metagenomics with nanopore sequencing provided thousands of high-contiguity genomes, phage and plasmid sequences (>60% novel), enabling characterization of resistome and mobilome diversity and dynamic architectures in hospital environments. Phylogenetics identified multidrug-resistant strains as being widely distributed and stably colonizing across sites. Comparisons with clinical isolates indicated that such microbes can persist in hospitals for extended periods (>8 years), to opportunistically infect patients. These findings highlight the importance of characterizing antibiotic resistance reservoirs in hospitals and establish the feasibility of systematic surveys to target resources for preventing infections.ISSN:1078-8956ISSN:1546-170

Cartography of opportunistic pathogens and antibiotic resistance genes in a tertiary hospital environment.

Although disinfection is key to infection control, the colonization patterns and resistomes of hospital-environment microbes remain underexplored. We report the first extensive genomic characterization of microbiomes, pathogens and antibiotic resistance cassettes in a tertiary-care hospital, from repeated sampling (up to 1.5 years apart) of 179 sites associated with 45 beds. Deep shotgun metagenomics unveiled distinct ecological niches of microbes and antibiotic resistance genes characterized by biofilm-forming and human-microbiome-influenced environments with corresponding patterns of spatiotemporal divergence. Quasi-metagenomics with nanopore sequencing provided thousands of high-contiguity genomes, phage and plasmid sequences (>60% novel), enabling characterization of resistome and mobilome diversity and dynamic architectures in hospital environments. Phylogenetics identified multidrug-resistant strains as being widely distributed and stably colonizing across sites. Comparisons with clinical isolates indicated that such microbes can persist in hospitals for extended periods (>8 years), to opportunistically infect patients. These findings highlight the importance of characterizing antibiotic resistance reservoirs in hospitals and establish the feasibility of systematic surveys to target resources for preventing infections

Three-Dimensional Rebar Graphene

Free-standing robust three-dimensional (3D) rebar graphene foams (GFs) were developed by a powder metallurgy template method with multiwalled carbon nanotubes (MWCNTs) as a reinforcing bar, sintered Ni skeletons as a template and catalyst, and sucrose as a solid carbon source. As a reinforcement and bridge between different graphene sheets and carbon shells, MWCNTs improved the thermostability, storage modulus (290.1 kPa) and conductivity (21.82 S cm^–1) of 3D GF resulting in a high porosity and structurally stable 3D rebar GF. The 3D rebar GF can support >3150× the foam’s weight with no irreversible height change, and shows only a ∼25% irreversible height change after loading >8500× the foam’s weight. The 3D rebar GF also shows stable performance as a highly porous electrode in lithium ion capacitors (LICs) with an energy density of 32 Wh kg^–1. After 500 cycles of testing at a high current density of 6.50 mA cm^–2, the LIC shows 78% energy density retention. These properties indicate promising applications with 3D rebar GFs in devices requiring stable mechanical and electrochemical properties