Digital dentistry plays a pivotal role in dental health care. A critical step in many digital dental systems is to accurately delineate individual teeth and the gingiva in the 3-dimension intraoral ...scanned mesh data. However, previous state-of-the-art methods are either time-consuming or error prone, hence hindering their clinical applicability. This article presents an accurate, efficient, and fully automated deep learning model trained on a data set of 4,000 intraoral scanned data annotated by experienced human experts. On a holdout data set of 200 scans, our model achieves a per-face accuracy, average-area accuracy, and area under the receiver operating characteristic curve of 96.94%, 98.26%, and 0.9991, respectively, significantly outperforming the state-of-the-art baselines. In addition, our model takes only about 24 s to generate segmentation outputs, as opposed to >5 min by the baseline and 15 min by human experts. A clinical performance test of 500 patients with malocclusion and/or abnormal teeth shows that 96.9% of the segmentations are satisfactory for clinical applications, 2.9% automatically trigger alarms for human improvement, and only 0.2% of them need rework. Our research demonstrates the potential for deep learning to improve the efficacy and efficiency of dental treatment and digital dentistry.
Abstract
The rotational reflex velocity (RRV) method was proposed by Heinze and Metchev in 2015 and was used to measure the distances of main-belt asteroids (MBAs). Later, Lin et al. generalized this ...method using spherical astronomy in 2016. The method measures the distances of MBAs using the observations from a single ground-based telescope over two nights. We refined this method and extend it further to the distance measurement of near-Earth asteroids (NEAs). In practice, we measure the distance of the potentially hazardous asteroid (99942) Apophis from the acquired CCD frames using the newly refined method. According to the requirement of the newly refined method, we also simulate the distance measurements of the four typical NEAs, (1221) Amor, (1862) Apollo, (2062) Aten, and (163693) Atira, on their discovery dates and follow-up dates. The measurement results of Apophis based on the newly refined RRV method show that the mean relative errors for the independent exposure frames on the successive two nights is ∼0.08% (about a factor of 2 improvement in comparison with the research of Lin et al.) compared with the distance from JPL ephemeris. Our simulation results also show that this refined method can accurately and precisely measure the distances of newly discovered NEAs in an astrometric way without performing orbital determination. The accurate and precise distances of newly discovered asteroids help us to conveniently evaluate their impact risks within a shorter time, leaving us more time to take defense precautions.
The buckling mode of a thin film lying on a soft substrate has been used to determine the elastic modulus of thin films and one-dimensional objects (e.g. nanowires and nanotubes). In this paper, ...dimensional analysis and three-dimensional nonlinear finite element computations have been made to investigate the buckling of a film with finite width bonded to a compliant substrate. Our study demonstrates that the effect of Poisson's ratio of the film can be neglected when its width-thickness ratio is smaller than 20. For wider films, omitting the influence of Poisson's ratio may lead to a significant systematic error in the measurement of the Young's modulus and, therefore, the film should be treated as a plate. It is also found that the assumption of the uniform interfacial normal stress along the width of the film made in the theoretical analysis does not cause an evident error, even when its width is comparable to its thickness. Based on the computational results, we further present a simple expression to correlate the buckling wavelength with the width and thickness of the film and the material properties (Young's moduli and Poisson's ratios) of the film and substrate, which has a similar form to that in the classical plane-strain problem. The fundamental solutions reported here are not only very accurate in a broad range of geometric and material parameters but also convenient for practical use since they do not involve any complex calculation.
PTEN and the pan phosphoinositide 3-kinase (PI3K) inhibitor 2-(4-morpholinyl)-8-phenyl-4H-1 benzopyran-4-one (LY294002) exert significant control over tumor-induced angiogenesis and tumor growth in ...vivo. The LY294002 compound is not a viable drug candidate due to poor pharmacologic variables of insolubility and short half-life. Herein, we describe the development and antitumor activity of a novel RGDS-conjugated LY294002 prodrug, termed SF1126, which is designed to exhibit increased solubility and bind to specific integrins within the tumor compartment, resulting in enhanced delivery of the active compound to the tumor vasculature and tumor. SF1126 is water soluble, has favorable pharmacokinetics, and is well tolerated in murine systems. The capacity of SF1126 to inhibit U87MG and PC3 tumor growth was enhanced by the RGDS integrin (alpha v beta 3/alpha 5 beta 1) binding component, exhibiting increased activity compared with a false RADS-targeted prodrug, SF1326. Antitumor activity of SF1126 was associated with the pharmacokinetic accumulation of SF1126 in tumor tissue and the pharmacodynamic knockdown of phosphorylated AKT in vivo. Furthermore, SF1126 seems to exhibit both antitumor and antiangiogenic activity. The results support SF1126 as a viable pan PI3K inhibitor for phase I clinical trials in cancer and provide support for a new paradigm, the application of pan PI3K inhibitory prodrugs for the treatment of cancer.
Development and Application of CAP1400 Numerical Reactor System CAO Liangzhi;DENG Li;YANG Bo;LIU Zhouyu;LIU Peng;TANG Chuntao;SHI Dunfu;CHEN Ronghua;TIAN Wenxi;PENG Lianghui;WAN Chenghui;ZHANG Minwan;BI Guangwen;FEI Jingran;XU Xiaobei;LI Fan
Yuanzineng kexue jishu,
02/2022, Letnik:
56, Številka:
2
Journal Article
Odprti dostop
Numerical reactor technology describes a variety of physical phenomena in the core of a nuclear reactor through highprecision, highresolution, high confidence and high fidelity numerical simulation ...method, based on highperformance calculation and multiphysics coupling, reveals the internal laws of various physical phenomena in nuclear reactors from mechanism, and accurately predicts the key safety parameters of nuclear reactors in service. It plays an important role in the whole life cycle of nuclear reactor R&D, design, safety analysis, operation support and decommissioning. This paper systematically introduces the main outcome of the major national science and technology project “Research on Key Technologies of CAP1400 Numerical Reactor” of “Largescale Advanced PWR and HTGR Nuclear Power Plant”. Firstly, the high fidelity reactor physics calculation codes based on deterministic method and Monte Carlo method were developed respectively, and then the pinbypin advanced subchannel analysis code and the fuel rod analysis code based on finemesh were developed. Based on those codes, the CAP1400 numerical reactor system with neutronics/thermalhydraulics/fuel performance multiphysics coupling was established. The numerical reactor system was verified and validated against the international benchmark VERA provided by CASL and AP1000 startup experimental data. For VERA problems, the comparison with the results of MC21/CTF coupling codes shows that the relative deviation of the power distribution of numerical reactor system is less than 25% for both Monte Carlo method and deterministic method. The maximum critical boron concentration deviation is less than 30 ppm. For AP1000 reactor of Sanmen unit 2, the deviations of developed numerical reactor compared with the measurements are as follows: 1) The maximum deviations of gray rod worth are -103 pcm, 73 pcm and 57 pcm, respectively; 2) The maximum relative deviation of black rod worth are 32%, -17% and 08%, respectively; 3) The ITC deviations are -0.597 pcm/℃, 0.280 pcm/℃, and 1570 pcm/℃, respectively. Compared with the industry codes, numerical reactor codes have higher precision. After verification and validation, the numerical reactor codes were applied to simulate the startup experiments of CAP1400 reactor. Taking the Monte Carlo results as references, the absolute deviation of the deterministic numerical reactor code for the critical boron concentration under HZP ARO condition is -236 ppm. The maximum absolute deviation for the value of the gray rod group (MA to MD) is -52 pcm, and for the black rod group, the maximum relative deviation of the value of (M1, M2, AO, SD1 to SD6) is 268%. The relative deviation of the total worth of black rods is -008%. Assembly power distributions of 14 core conditions were compared between Monte Carlo code and deterministic code. The most positive value of relative deviation is 224%, the most negative value is -247%, the average value is -006% and the standard deviation is 102%. The above numerical results show that the developed numerical reactor analysis program has high calculation accuracy and can directly serve the design verification, startup and operation support of CAP1400.
To determine the effects of loading on active and passive tensions, programmed cell death, superoxide anion formation, the expression of Fas on myocytes, and side-to-side slippage of myocytes, ...papillary muscles were exposed to 7-8 and 50 mN/mm2 and these parameters were measured over a 3-h period. Overstretching produced a 21- and a 2.4-fold increase in apoptotic myocyte and nonmyocyte cell death, respectively. Concurrently, the generation of reactive oxygen species increased 2.4-fold and the number of myocytes labeled by Fas protein 21-fold. Moreover, a 15% decrease in the number of myocytes included in the thickness of the papillary muscle was found in combination with a 7% decrease in sarcomere length and the inability of muscles to maintain stable levels of passive and active tensions. The addition of the NO-releasing drug, C87-3754, prevented superoxide anion formation, programmed cell death, and the alterations in active and passive tensions with time of overloaded papillary muscles. In conclusion, overstretching appears to be coupled with oxidant stress, expression of Fas, programmed cell death, architectural rearrangement of myocytes, and impairment in force development of the myocardium.
A measurement of the energy dependence of antineutrino disappearance at the Daya Bay reactor neutrino experiment is reported. Electron antineutrinos (ν¯(e)) from six 2.9 GW(th) reactors were ...detected with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls. Using 217 days of data, 41 589 (203 809 and 92 912) antineutrino candidates were detected in the far hall (near halls). An improved measurement of the oscillation amplitude sin(2)2θ(13)=0.090(-0.009)(+0.008) and the first direct measurement of the ν¯(e) mass-squared difference |Δm(ee)2|=(2.59(-0.20)(+0.19))×10(-3) eV2 is obtained using the observed ν¯(e) rates and energy spectra in a three-neutrino framework. This value of |Δm(ee)2| is consistent with |Δm(μμ)2| measured by muon neutrino disappearance, supporting the three-flavor oscillation model.
A novel two-step intercritical annealing process was designed for an ultra-low carbon medium manganese steel plate. Excellent mechanical properties with yield strength of 590MPa, tensile strength of ...840MPa, total elongation of 28.5% and high impact energy of 106J at −80°C were obtained. The microstructure comprised of ultra-fine grained ferrite and retained austenite together with a small amount of martensite after the two-step intercritical annealing. Both lath-like and blocky retained austenite with volume fraction of ~25% and relatively poor stability were obtained. The submicron-sized lath-like retained austenite exhibited Nishiyama-Wassermann (N-W) orientation relationship with the neighboring martensitic ferrite lath. The fine grain size played a crucial role in stabilizing austenite during phase transformation by significantly lowering Ms temperature and increasing the elastic strain energy. The overall stability of retained austenite during deformation was considered to be mainly governed by the chemical composition of the studied steel. The mechanism of toughening was elucidated. The superior low-temperature toughness was associated with TRIP effect of metastable retained austenite, which relieved the local stress concentration, enhanced the ability to plastic deformation and delayed the initiation and propagation of microcracks.
The Levant constitutes an important region for assessing linkages between climate and societal changes throughout the course of human history. However, large uncertainties remain in our understanding ...of the region's hydroclimate variability under varying boundary conditions. Here we present a new high‐resolution, precisely dated speleothem oxygen‐carbon isotope and Sr/Ca records, spanning the last 20 ka from Jeita Cave, northern Levant. Our record reveals a higher (lower) precipitation‐evaporation (P‐E) balance during the Last Glacial Maximum and Bølling interstadial (Heinrich stadial 1). The early‐middle Holocene is characterized by a trend toward higher P‐E state, culminating between ~7 and 6 ka. The middle‐late Holocene is characterized by two millennial‐length drier periods during 5.3–4.2 and 2.8–1.4 ka. On submillennial time scale, the northern Levant climate variability is dominated by 500 year periodicity. Comparisons with the regional proxy records suggest persistent out‐of‐phase climate variability between the northern and southern Levant on a wide range of timescales.
Key Points
High‐resolution speleothem record is established in northern Levant in the last 20 ka
The Climate variability on various timescales in northern Levant is characterized
Climate variations are out of phase between northern and southern Levant
Currently, antimicrobial peptides (AMPs) are of growing interest as potential substitutes for antibiotic growth promoters in animal production. The present study was conducted to evaluate the effects ...of dietary supplementation of bioengineering artificial Parasin I protein (API) and artificial plectasin protein (APL) (named as compound bioengineering protein, CBP) on growth performance and intestinal health of broilers. A total of 450 one-day-old Arbor Acres male healthy broilers were randomly allotted to 5 dietary groups with 10 replicates of 9 individuals in each replicate and supplemented with 0, 250, 500, 750, and 1,000 mg/kg CBP for 6 wk. Dietary CBP supplementation increased (P < 0.01) body weight (6 wk), average daily gain (0–6 wk), and average daily feed intake (3–6 wk and 0–6 wk). CBP addition enhanced antioxidant capacity, which was accompanied by the higher (P < 0.05) activity of serum total antioxidant capacity (T-AOC) (750 mg/kg), jejunal glutathione peroxidase (750 mg/kg), and T-AOC (500 and 1,000 mg/kg). Dietary CBP addition improved intestinal health, reflecting by the increased (P < 0.05) villus height to crypt depth ratio in the duodenum, the upregulated (P < 0.01) mRNA levels of claudin-1 (500 and 750 mg/kg) in the ileum, the downregulated (P < 0.01) mRNA expression of occludin (500 mg/kg) in the duodenum and claudin-1 (500 mg/kg) and occludin (500 and 750 mg/kg) in the jejunum, and the upregulated mRNA expression of (P < 0.01) mucin2 (MUC2) (1,000 mg/kg) in the duodenum. In addition, CBP upregulated (P < 0.01) IL-10 (1,000 mg/kg) in duodenum and ileum, and downregulated (P < 0.05) the mRNA expression of IL-6 (750 and 1,000 mg/kg), interferon-γ (1,000 mg/kg) in the jejunum and TNF-α (250 mg/kg) in the ileum. Furthermore, dietary CBP increased (P < 0.01) the abundance of total bacteria and Lactobacillus (500 and 750 mg/kg), and reduced (P < 0.05) the abundance of Escherichia coli (750 mg/kg) in the cecum. In conclusion, CBP supplementation enhances the antioxidant capacity, intestinal health, immune function, and ameliorates the gut microflora population, thus improving the growth performance of broilers. Dietary supplementation of 750 mg/kg CBP exhibits a better beneficial effect.
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