•A damage localization method by using the indirectly measured mode shapes.•Mode shape is extracted from the moving vehicle response via Hilbert transform.•Regional mode shape curvature is defined to ...formulate damage localization index.•Numerical studies are conducted to verify the proposed method.
Mode shape curvature change has been regarded as a promising damage localization index (DLI). However, its application is limited by the requirement for high spatial resolution and reference mode shapes, and the central difference method induced low anti-noise ability. This paper aims to develop a new damage localization method by using the mode shapes extracted from moving vehicle response for beam structures without reference data. The first order mode shape with high spatial resolution in damaged state is extracted from the response measured on a moving vehicle via Hilbert transform (HT). Then regional mode shape curvature (RMSC) in damaged state which takes advantage of the high spatial resolution of mode shapes provided by moving vehicle test is defined to enhance the anti-noise ability. Subsequently the RMSC in undamaged state is estimated by the RMSC in damaged state and polynomial approximation under the assumption that RMSC in undamaged state has smooth surface. Finally an index is formulated based on RMSC before and after damage to localized damage. Numerical studies are conduced to investigate the effect of noise, moving velocity, uneven distribution of beam flexural rigidity, and road roughness on the accuracy of the proposed DLI.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Excessive type 2 helper T cell responses to environmental antigens can cause immunopathology such as asthma and allergy, but how such immune responses are induced remains unclear. We studied this ...process in the airways by immunizing mice intranasally with the antigen ovalbumin together with either of two Toll-like receptor (TLR) ligands. We found the TLR5 ligand flagellin promoted a type 2 helper T cell response, whereas, a TLR9 ligand CpG oligodeoxyribonucleotide (ODN) promoted a type 1 helper T cell response. CpG ODN induced mRNA encoding interleukin (IL)-12 p40, whereas, flagellin caused IL-33 secretion and induced mRNAs encoding IL-1 and thymic stromal lymphopoietin (TSLP). By using mice deficient in the TLR and IL-1R signaling molecule, myeloid differentiation primary response 88 (MyD88), in conventional dendritic cells (cDCs) and alveolar macrophages (AMs), and by cell sorting different lung populations after 2 hours of in vivo stimulation, we characterized the cell types that rapidly produced inflammatory cytokines in response to TLR stimulation. CpG ODN was likely recognized by TLR9 on cDCs and AMs, which made mRNA encoding IL-12. IL-12 was necessary for the subsequent innate and adaptive interferon-γ production. In contrast, flagellin stimulated multiple cells of hematopoietic and non-hematopoietic origin, including AMs, DCs, monocytes, and lung epithelial cells. AMs were largely responsible for IL-1α, whereas lung epithelial cells made TSLP. Multiple hematopoietic cells, including AMs, DCs, and monocytes contributed to other cytokines, including IL-1β and TNFα. MyD88-dependent signals, likely through IL-1R and IL-33R, and MyD88-independent signals, likely from TSLP, were necessary in cDCs for promotion of the early IL-4 response by CD4 T cells in the draining lymph node. Thus, the cell types that responded to TLR ligands were a critical determinant of the innate cytokines produced and the character of the resulting adaptive immune response in the airways.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Binary radio pulsars are generally believed to have been spun up to millisecond periods (i.e. recycling) via mass accretion from their donor stars, and they are the descendants of neutron star ...low-mass X-ray binaries. However, some studies indicate that the formation of pulsars from the accretion-induced collapse (AIC) of accreting white dwarfs (WDs) cannot be excluded. In this work, we use a population-synthesis code to examine if the AIC channel can produce eccentric binary millisecond pulsars (BMSPs) in the Galaxy. Our simulated results indicate that only when the natal MSPs receive a relatively strong kick (>rsim 100 km s −1), can the AIC channel produce ∼10-180 eccentric (e > 0.1) BMSPs in the Galaxy, most of which are accompanied by a helium star. Such a kick seems to be highly unlikely in the conventional AIC process, hence the probability of forming eccentric BMSPs via the AIC channel can be ruled out. Even if a high kick is allowed, the AIC channel cannot produce eccentric BMSPs with an orbital period of ≳20 d. Therefore, we propose that the peculiar BMSP PSR J1903+0327 cannot be formed by the AIC channel. However, the AIC evolutionary channel may produce some fraction of isolated MSPs, and even submillisecond pulsars if they really exist.
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BFBNIB, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
In this paper, high-order compact finite volume schemes on the unstructured grids based on the variational reconstruction are developed to solve the Reynolds averaged Navier-Stokes equations closed ...by the Spalart-Allmaras one-equation turbulence model. Encouraging progress is made in addressing the following two challenging problems: reducing the numerical errors on the large aspect ratio grids and avoiding the negative turbulent viscosity associated with the high-order methods. On grids with large aspect ratios, a three-step procedure is designed to optimize the functional parameters of variational reconstruction. In addition, an exponential decay procedure is proposed to cure the negative turbulent viscosity problem of the Spalart-Allmaras model. The exponential decay procedure has the advantage of being able to be used with any spatial discretization method and with the implicit temporal discretization. Numerical tests show significant benefits of the high-order schemes in predicting the skin frictions, capturing some important flow structures, and achieving grid-independent solutions. The numerical tests also show that the proposed schemes are sufficiently robust for practical applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
FRP composites have been used for strengthening RC and masonry structures for decades. However, the researches on repairing multistorey masonry structures using FRP grids were relative less. In the ...present paper, an experimental study on the seismic performance of multistorey masonry structure with openings repaired with CFRP grid is introduced. Specifically, a 1/3-scale three-floor masonry wall with window openings was tested under quasistatic action to simulate the seismic damages. The damaged masonry wall was then repaired by externally bonding CFRP grids to the areas where the cracks intensively occurred. The repaired masonry wall was retested under the same loading to investigate the seismic resistance and assess the recovery attributed from the CFRP grid repairing. The findings of this study showed that CFRP grid repairing could effectively postpone or even prevent the occurrence and development of cracking. The seismic resistance of the masonry, including shear capacity, energy dissipation capacity, deformability, stiffness degradation, and ductility, was restored. The application of CFRP grid may shift the failure mechanism of the multistorey masonry wall. The recommendation of repair scheme for the similar structures was also proposed in accordance with the findings of the present work.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
China's first Mars exploration mission,Tianwen-1,successfully landed in southern Utopia Planitia on Mars on May 15,2021.This work presents a detailed investigation of the geologic context of the ...landing area surface for this mission based on orbital remote-sensing data.We constructed a geomorphologic map for the Tianwen-1 landing area.Results of our detailed geomorphologic map show several major landforms within the landing area,including rampart craters,mesas,troughs,cones,and ridges.Analysis of materials on the landing area surface indicates that most of the landing area is covered by Martian dust.Transverse aeolian ridges are widely distributed within the landing area,indicating the surface contexts were(and still are)modified by regional winds.In addition,a crater counting analysis indicates the landing area has an absolute model age of～3.3 Ga and that a later resurfacing event occurred at～1.6 Ga.Finally,we outline four formational scenarios to test the formation mechanisms for the geomorphologic features on the landing area surface.The most likely interpretation to explain the existence of the observed surface features can be summarized as follows:A thermal influence may have played an important role in the formation of the surface geomorphologic features;thus,igneous-related processes may have occurred in the landing area.Water ice may also have been involved in the construction of the primordial surface configuration.Subsequent resurfacing events and aeolian processes buried and modified the primordial surface.
•A Markov chain Monte Carlo-based Bayesian method for nonlinear stochastic model updating is proposed.•The mono-components and their instantaneous features are extracted from the structural dynamic ...response by using the discrete analytical mode decomposed method.•The posterior probability density function (PDF) associated with Bayesian method is derived by using instantaneous characteristics.•The delayed rejection adaptive metropolis-hastings (DRAM) algorithm is implemented with the advantages of strong adaptive and fast convergence.•Numerical and experimental investigations are conducted to validate the approach.
This paper proposes a Markov Chain Monte Carlo (MCMC)-based Bayesian method for nonlinear stochastic model updating by using the instantaneous characteristics of the structural dynamic responses. According to the discrete analytical mode decomposed method and Hilbert transform, the instantaneous characteristics of the mono-components are firstly extracted from the structural dynamic response and applied to the calculation of likelihood function. Then, the posterior probability density function associated with Bayesian theorem is derived under the assumption of Gaussian prior distribution by using instantaneous characteristics. Afterwards, to calculate the posterior probability density function and improve the sampling efficiency, the delayed rejection adaptive Metropolis-Hastings (DRAM) algorithm is implemented with the advantages of strong adaptive and fast convergence. In the process of Bayesian inference, the posterior samples generated by DRAM require vast quantities of finite element analysis to guarantee the accuracy. For reducing the computational cost, the response surface model is constructed to establish the mathematical regression model between the structural parameters and the theoretical dynamic responses. To validate the effectiveness and applicability of the proposed method, the numerical cases on a three-story nonlinear structure under earthquake excitation considering various noise level effects and an Iwan beam model with two types of excitations are simulated. In addition, an experimental validation on a ¼ scale, 3-story steel frame structure subjected to a series of earthquake excitations in the laboratory is also performed to further verify the proposed method. Both the numerical and experimental results demonstrate that the DRAM-based Bayesian method can be effectively used to update nonlinear stochastic models with a high accuracy.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background
This study aimed to evaluate the performance of two different principles of HPV testing in primary cervical cancer screening and ASC-US triage in rural areas.
Methods
3,328 and 3,913 women ...were enrolled in Shanxi, China in 2017 and 2018, respectively, and screened using liquid-based cytology and different HPV tests with a 4-year follow-up. Different screening methods commonly used in clinical practice were evaluated.
Results
In the HPV PCR test cohort, the prevalence of HPV infection was 14.90%. A total of 38 cases of CIN2+ were identified at baseline, 2 of which were in the HPV-negative cohort and the rest in the HPV-positive cohort (2 = 186.85,
p
< 0.001). Fifty-three cases of CIN2+ were accumulated over 4 years. The HPV infection rate in the HPV DNA chip test cohort was 21.10%. A total of 26 CIN2+ cases were identified at baseline, all in the HPV-positive population (2 = 92.96,
p
< 0.001). 54 CIN2+ cases were cumulative over 4 years. At 4-year follow-up, HPV-negative results were significantly more protective against cervical intraepithelial neoplasia grade 2 or worse (CIN2+) than normal cytologic results at baseline. HPV screening was more sensitive and specific than cytologic screening (using ASC-US as the threshold) and performed better on the HPV DNA microarray test. In addition, compared with HPV 16/18 testing, sensitivity increases and specificity decreases when using HPV testing for cytologic ASC-US triage, regardless of which HPV test is used.
Conclusion
In the rural areas where we implemented the study, HPV tests performed well for screening than LBC and HPV DNA chip testing performed better than HPV PCR testing in the screening cohort. Optimal screening was achieved technically when used in combination with LBC for ASC-US population triage, without thinking the feasibility for resource availability.
Picric acid (PA) is a lethal explosive substance that is easily soluble in water and harmful to the environment. Here, a supramolecular polymer material BTPY@Q8 with aggregation induced emission ...(AIE) was prepared by supramolecular self-assembly of cucurbit uril (Q8) and 1,3,5-tris4-(pyridin-4-yl) phenyl benzene derivative (BTPY), which exhibited aggregation-induced fluorescence enhancement. To this supramolecular self-assembly, the addition of a number of nitrophenols was found to have no obvious effect on the fluorescence, however on addition of PA, the fluorescence intensity underwent a dramatic quench. For PA, BTPY@Q8 had sensitive specificity and effective selectivity. Based on this, a quick and simple on-site visual PA fluorescence quantitative detection platform was developed using smart phones, and the platform was used to monitor temperature. Machine learning (ML) is a popular pattern recognition technology, which can accurately predict the results from data. Therefore, ML has much more potential for analyzing and improving sensing data than the widely used statistical pattern recognition method. In the field of analytical science, the sensing platform offers a reliable method for the quantitative detection of PA that can be applied to other analytes or micropollutant screening.
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•A cucurbit8uril-based supramolecular assembly BTPY@Q8 was fabricated.•Assembly can be used as a good fluorescence sensing material.•A quick and simple on-site visual Picric acid fluorescence quantitative detection platform was developed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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