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Early detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is an efficient way to prevent the spread of coronavirus disease 2019 (COVID-19). Detecting SARS-CoV-2 antigen can be rapid and convenient, but it is still challenging to develop highly sensitive methods for effective diagnosis. Herein, a lateral flow assay (LFA) based on fluorescent nanoparticles emitting in the second near-infrared (NIR-II) window is developed for sensitive detection of SARS-CoV-2 antigen. Benefiting from the NIR-II fluorescence with high penetration and low autofluorescence, such NIR-II based LFA allows enhanced signal-to-background ratio, and the limit of detection is down to 0.01 ng·mLSupplementary material (the operation procedure and cost of the materials needed of NIR-II lateral flow assays, the dynamic light scattering spectrum of the NIR-II nanoparticles, the components and testing principle, optimization of main parameters pertaining to the LFA performance, the colloidal gold LFA strip, the fluorescence intensity distribution curves and the T/C values of the strips for clinical samples by NIR-II LFA, and results of clinical swab samples detected by colloidal gold LFA) is available in the online version of this article at 10.1007/s12274-022-4351-1.

Product development should cover product design, validation, and manufacturing. In traditional product development, physical validation based on physical trial manufacturing is the key step to confirm the design scheme before physical manufacturing. However, physical validation is costly and inefficient, which could be the main obstacle to achieving rapid product development. The emergence of digital twin provides an opportunity to accelerate product development by eliminating physical validation toward digital validation in the smart manufacturing era. Therefore, a framework of rapid product development based on digital twin is proposed in this paper. During product development, the new product is designed according to the new requirements in the virtual space, in which the existing digital twins of products can be referenced. Then, an ultrahigh-fidelity virtual manufacturing system is constructed for digital trial manufacturing based on the digital twin of the manufacturing system and the design scheme of the new product. An ultrahigh-fidelity digital prototype can be obtained from digital trial manufacturing for digital validation. The new product validation is executed on the digital prototype to test its performance. The digital validation results can be used to improve the design scheme of the new product and boost the corresponding manufacturing processes. In addition, the core characteristics and key technologies of rapid product development based on digital twin are discussed. Finally, a case study is presented to implement the proposed framework and to show the effectiveness of accelerating product development.

BACKGROUND Endoscopic ultrasound-guided gastroenterostomy (EUS-GE) is widely used in patients with gastric outlet obstruction (GOO). Recurrence of obstruction symptoms caused by stent migration is the major reason for reintervention in EUS-GE. To solve this problem, we proposed developing a double anchor lock (DAL) fixing stent method for EUS-GE. The safety and efficacy of the DAL fixing stent method were evaluated in this study. METHODS Sixteen Bama miniature pigs were randomly divided into an experimental group (n = 8) and a control group (n = 8). A gastric outlet obstruction model was established for all the pigs. The experimental group was treated with the DAL fixing stent method for EUS-GE, while the control group was treated with EUS-GE. Three-month stent migration rate, remission rate of GOO, re-occlusion intervention rate, weight change, and incidence of procedure-related complications of EUS-GE were analyzed and estimated in the two groups. RESULTS EUS-GE was successfully completed in every subject in both groups. Symptoms of digestive tract obstruction can be relieved in all animals. The stent existence rate in the 3 months was higher in the experimental group than in the control group (87.5% vs. 12.5%, P = 0.012). Except for one animal in the experimental group in which there was pneumoperitoneum due to a stent insertion failure, no animal experienced bleeding or perforation. CONCLUSION The DAL fixing stent method, which can effectively prevent stent migration, is safe and simple. EUS-GE can effectively relieve the symptoms of digestive tract obstruction.

Generated by the immune system post-infection or through vaccination, the effectiveness of antibodies against emerging SARS-CoV-2 variants is crucial for protecting individuals from the COVID-19 pandemic. Herein, a platform for the multiplexed evaluation of SARS-CoV-2 neutralizing antibodies against various variants was designed on the basis of near-infrared (NIR) surface enhanced fluorescence by nano-plasmonic gold chip (pGOLD). Antibody level across variants (Wild-type, Alpha, Beta, Delta, Omicron) was confirmed by the sera from recovered-individuals who were unvaccinated and had infected with Wild-type, Delta, Omicron variants. However, the neutralizing activity against Omicron variant was markedly decreased for individuals infected by Wild-type (~ 5.6-fold) and Delta variant (~ 19.1-fold). To the opposite, neutralizing antibody from individuals recovered from Omicron variant infection showed weak binding strength against non-Omicron variants. Antibody evolution over time was studied with individuals 196–530 days post Wild-type infection. Decreasing IgG antibody titer accompanied by increasing IgG binding avidity with elongated post-infection period were observed for the sera from Wild-type recovered-individuals with different post-infection times, suggesting that after the primary infection, a great number of antibodies were generated and then gradually decreased, while the antibody matured over time. By comparing the IgG level of individuals vaccinated for 27–51 days with individual post-infection, we found that ca. 1 month after two doses of vaccination, the antibody level was comparable to that of 500 days post-infection, and vaccination could enhance IgG avidity more efficiently. This work demonstrated a platform for the multiplexed, high-throughput and rapid screening of acquired immunity against SARS-CoV-2 variants, providing a new approach for the analysis of vaccine effectiveness, immunity against emerging variants, and related serological study. Graphical Abstract

Three-dimensional magnetic resonance elastography (3D-MRE) allows for multiparametric modeling of both elastic and viscous tissue characteristics. Our aim was to compare 3D-MRE with conventional liver shear stiffness assessment in gauging obstructive jaundice (OJ), predicting the adequacy of biliary decompression after drainage, and discriminating OJ from liver fibrosis. Patients with no histories of liver disease (n = 201) were studied in retrospect, grouped by bilirubin levels as no jaundice (NJ ≤ 2 mg/dL; n = 75), mild OJ (>2 mg/dL and ≤ 4 mg/dL; n = 56), and severe OJ (> 4 mg/dL; n = 70). For comparison, another 75 patients with chronic hepatitis B and C infections and histologically proven liver fibrosis were similarly analyzed. Each patient underwent spin-echo echo-planar-imaging MRE at 60 Hz with 3D wave postprocessing. Logistic regression and ordinary regression models were used to compare the 3D-MRE model with liver shear stiffness. Liver shear stiffness, loss modulus, and damping ratio were incorporated into a 3D-MRE model, which significantly outperformed shear stiffness in predicting OJ severity (accuracy: 0.801 vs 0.672; p

Most damaged reinforced concrete (RC) frame structures still can be used after earthquake, it is important to assess the residual performance of damaged structures. However, quantitatively evaluate the residual performance of damaged structures still presents difficulties due to the lack of suitable indicators. For studying and estimating the residual bending bearing capacity (RBC) of RC columns under cyclic loading properly, a new method is proposed, which is characterized based on fiber-beam element damage in section. Firstly, two quantitative indexes, fiber damage index (FDI) and section damage index (SDI) based on fiber-beam elements, are suggested. Weak section (the most damaged part on column) of RC column can be determined utilizing the SDI. Moreover, based on comparison between test and calculation, the section damage status of RC column can be described by FDI. And then a procedure for obtaining RBC considering the damage of the RC column is also introduced, and taking a RC column specimen as an example to realize and examine the whole calculation procedure proposed. Furthermore, for determining RBC of testing specimen, a rule for determining the failure point of RC columns under cyclic loading is proposed and verified. By comparing the RBC determined by the experiment and the calculation of 21 RC columns in the Pacific Earthquake Engineering Research Center structural performance database(PEERSPD), our suggested method of computing the RBC is verified too, which proves that new method can quantitatively assess the performance of the members under cyclic loading.

The strength reduction method (SRM) is one of the main methods for evaluating slope stability and its key step is to select failure criteria reasonably and correctly. At present, non-convergence of numerical iteration, penetration of plastic zone, and the catastrophe of characteristic points displacement are usually used as slope failure criteria. To avoid the randomness of selecting characteristic points and the subjective error, this paper presents a new criterion: residual displacement increment criterion based on the displacement catastrophe criterion of characteristic points. In this criterion, the average residual displacement increment is calculated after each reduction, and the strength reduction factor corresponding to the maximum average residual displacement increment is regarded as the safety factor of the slope. This new criterion avoids the randomness of selecting characteristic points and the subjective error of judging the displacement mutation point artificially. The two-dimensional slope stability calculated by this criterion is compared with the other three criteria and Spencer method, which verifies the applicability and accuracy of this criterion.

Reconfigurable machine tools (RMT) are the core facility of reconfigurable manufacturing systems (RMS), and structure design is the fundamental research involving RMT. The existing prototypes of RMT are limited to a specific part family, which suffers from reconfiguration difficulty and module sustainability issues. Therefore, a design philosophy of RMT for multi-part families with new design principles based on reconfigurability is proposed in this paper. Modularity and integrability are the basic principles, scalability, convertibility, and customization are the primary design principles, and reusability and symmetry are the auxiliary design principles. By implementing the new design principles, a two-step design method of RMT is proposed. First, a basic three-main-module structure, including the base, function arm, and workstation, is created. Second, customized components are selected to customize the functions for a specific part family, which can be reconfigured to meet the demand of other part families using other customized components. A prototype of RMT illustrates the proposed design philosophy to specify the basic three-main-module structure. The basic configurations of the RMT prototype are given, as well. The reconfigurability of the RMT prototype is analyzed from the perspectives of scalability, convertibility, and reconfiguration time. Based on topology optimization, the performance of the RMT prototype is improved. The case study implements milling and turning functions, demonstrating the practicality of the proposed design philosophy, where the processing of typical parts is also analyzed. Furthermore, the reconfiguration process among multi-part families is discussed in the case study.

The design earthquake is usually specified as a single event in most of modern seismic codes. However, one earthquake is often followed by a series of aftershocks called seismic sequence. Such cases are quite common, especially in near-fault regions, which could cause additional accumulated damage to structures. In this paper, a new methodology for evaluating the effect of near-fault seismic sequences on the accumulated damage of reinforced concrete (RC) frame structure is proposed, in which different initial damage levels (i.e., postmainshock global damage index) of structure after the mainshock are considered. Meanwhile, a quantitative description of the damage demands and the relative intensity index between mainshock and aftershock are provided. For this purpose, the nonlinear dynamic response of an eight-story RC frame structure subjected to single earthquake and seismic sequence is compared in terms of structural performance indices (collapse capacity, story damage demands, postmainshock damage level and normalized hysteretic energy) and relative intensity index. The results indicated that seismic sequences lead to reduced collapse capacity of postmainshock-damaged structures. Moreover, the near-fault pulse-like aftershock records would induce larger structural story damage demands than ordinary (i.e., non-pulse-like) aftershock records. Furthermore, the relative intensity index proposed in this paper has significant effects on the structural story damage demands, incremental dynamic analysis curves of aftershock and normalized hysteretic energy.

In order to improve the precision of extracting vulnerability index of ecological environment, a vulnerability influencing factors model of ecological environment based on partial differential equation is proposed and constructed. Using SAR to collect remote sensing image of ecological environment, the P-M diffusion equation of partial differential equation is introduced to detect the change of SAR image. According to the characteristics of logarithmic transformation, the multiplicative speckle noise in the image can be transformed into additive noise. Firstly, the image is logarithmic transformed, then the noise in the image is filtered by the P-M diffusion equation denoising model, and then the difference image is obtained by the logarithmic domain difference method. Finally, the difference image is classified by FCM clustering algorithm and the change area is extracted. Based on the test results, according to the principles of systematization, typicality, dynamics, conciseness, scientificity, operability, quantification and comprehensiveness, the main factors are ecological sensitivity and forest landscape pattern, including altitude, slope, land use type, landscape separation degree, landscape fractal dimension, patch density, landscape connectivity index, landscape aggregation degree, and patch cohesion indexes to build the system of ecological environment vulnerability factors. The experimental results show that the partial differential equation has a good denoising detection effect, and the influence factors are used in the prediction of ecological environment vulnerability. The prediction results have a high accuracy, indicating that the selected factors are reliable.

Reconfigurable machine tools (RMTs) are important equipment for enterprises to cope with ever-changing markets because of their flexibility. In design of such equipment, selection of appropriate modules is a very critical decision factor to effectively and efficiently satisfy manufacturing requirements. However, the selection of appropriate modules is a challenging task because it is a multi-domain mapping process relying heavily on experts’ domain knowledge, which is usually unstructured and implicit. To effectively support RMT designers, an ontology-based RMT module selection method is proposed. First, a knowledge base is built by development of an ontology to formally represent the taxonomy, properties, and causal relationships of/among three domain core concepts, namely, machining feature, machining operation, and RMT module involved in RMT design. Second, a four-step sequential procedure is established to facilitate the utilization of encoded knowledge from a knowledge base to aid in the selection of appropriate RMT modules. The procedure takes a given part family as the input, automatically infers the required machining operations as well as the RMT modules through rule-based reasoning, and eventually forms a set of RMT configurations that are capable of machining the part family as the output. Finally, the efficacy of the ontology-based RMT module selection method is demonstrated using a plate family manufacturing example. Results show that the approach is effective to support designers by appropriately and rapidly selecting modules and generating configurations in RMT design.

The prediction and assessment of the loss of group residential buildings under fierce winds are not only an important but also a very basic work. Many rural buildings, especially situated in southeastern of China, have suffered great damage and losses during such wind events in past 10 years. One new methodology is proposed in this study in order to estimate and evaluate the loss reasonably based on group building types and distribution, wind intensities and directions. This methodology comprehensively considers the mechanisms of interaction between the roof tiles, roof panels, doors and windows, which are more likely damaged seriously during fierce winds, the physical properties of those components, the wind pressure coefficients on the surface of group buildings in different wind directions, etc. Then Monte Carlo simulation is used to estimate the damage of group residential buildings under simulated fluctuating winds with different speeds and measured typhoon records. The simulation results indicate that our proposed quantified assessment method can be utilized for official, developers, architects, designers and homeowners to estimate and mitigate the losses that might be experienced during wind-related disasters either pre- or post-construction.

Rich nitrogen-doped mesoporous graphene (NDMG) with a large specific surface area of 496.8 m2 g−1 and high electrical conductivity of 327.2 S cm−1, and suitable pore size was synthesized by a facile co-thermal annealing of pre-prepared phenolic polymer and dicyandiamide. The NDMG has a high nitrogen content (7.9 wt%) and can act as promising electroactive materials for two-electrode symmetric supercapacitors. The NDMG cells displayed a high specific capacitance of ca. 316 F g−1 at 0.5 A g−1, which is much higher than that of the pristine graphene devices (ca. 123 F g−1). Moreover, compared with the capacitance drop rate of pristine graphene devices (8.9 %), the specific capacitance of NDMG cells was decreased by only 3.2 % after 2000 cycles, exhibiting a good cycling performance and reversibility. In addition, the specific capacitance of the NDMG cells can reach 251 F g−1 at 5.0 A g−1, revealing an excellent rate capability and implying the ability to deliver a high energy density at a high power density. The good electrochemical performances of NDMG can be attributed to its high surface area, suitable mesopore size, and high electrical conductivity.

A new stochastic ground motion model for generating a suite of ground motion time history with both temporal and frequency nonstationarities for specified earthquake and site characteristics is proposed based on the wavelet method. This new model is defined in terms of 6 key parameters that characterize the duration, evolving intensity, predominant frequency, bandwidth and frequency variation of the ground acceleration process. All parameters, except for peak ground acceleration (PGA), are identified manually from a database of 2444 recorded horizontal accelerations. The two-stage regression analysis method is used to investigate the inter- and intra-event residuals. For any given earthquake and site characteristics in terms of the fault mechanism, moment magnitude, Joyner and Boore distance and site shear-wave velocity, sets of the model parameters are generated and used, in turn, by the stochastic model to generate strong ground motion accelerograms, which can capture and properly embody the primary features of real strong ground motions, including the duration, evolving intensity, spectral content, frequency variation and peak values. In addition, it is shown that the characteristics of the simulated and observed response spectra are similar, and the amplitude of the simulated response spectra are in line with the predicted values from the published seismic ground motion prediction equations (SGMPE) after a systematic comparison. The proposed method can be used to estimate the strong ground motions as inputs for structural seismic dynamic analysis in engineering practice in conjunction with or instead of recorded ground motions.

By applying comparative genomics analyses, a high-density genetic linkage map of the Wax 1 ( W1 ) locus was constructed as a framework for map-based cloning. Glaucousness is described as the scattering effect of visible light from wax deposited on the cuticle of plant aerial organs. In wheat, the wax on leaves and stems is mainly controlled by two sets of genes: glaucousness loci (W1 and W2) and non-glaucousness loci (Iw1 and Iw2). Bulked segregant analysis (BSA) and simple sequence repeat (SSR) mapping showed that Wax1 (W1) is located on chromosome arm 2BS between markers Xgwm210 and Xbarc35. By applying comparative genomics analyses, colinearity genomic regions of the W1 locus on wheat 2BS were identified in Brachypodium distachyon chromosome 5, rice chromosome 4 and sorghum chromosome 6, respectively. Four STS markers were developed using the Triticum aestivum cv. Chinese Spring 454 contig sequences and the International Wheat Genome Sequencing Consortium (IWGSC) survey sequences. W1 was mapped into a 0.93 cM genetic interval flanked by markers XWGGC3197 and XWGGC2484, which has synteny with genomic regions of 56.5 kb in Brachypodium, 390 kb in rice and 31.8 kb in sorghum. The fine genetic map can serve as a framework for chromosome landing, physical mapping and map-based cloning of the W1 in wheat.

Background Endoscopic full-thickness resection (EFTR) is a mini-invasive technique for gastric subepithelial tumors originating from the muscularis propria, which enables a full-thickness resection of tumors and can provide a complete basis for pathological diagnosis. Gastric fistula closure after EFTR is a challenge for endoscopists. In this study, we introduced EFTR with fistula closure using the over-the-scope clip (OTSC) system for gastric subepithelial tumors originating from the muscularis propria. Objectives To evaluate the feasibility and safety of fistula closure with OTSC by a retrospective analysis on the cases of EFTR with defect closure using OTSC for gastric subepithelial tumors originating from the muscularis propria in our hospital. Methods The patients were selected who underwent EFTR for gastric subepithelial tumors originating from the muscularis propria (tumor diameter ≤2 cm) in our hospital from October 2013 to March 2014. After a full-thickness resection of tumors, the bilateral gastric mucous membranes of defect were clamped using twin graspers and then drawn into the transparent cap of OTSC, and the OTSC was released to close the defect after full suctioning. The success rate of defect closure with OTSC was observed, and the endoscopic follow-up was performed at 1 week, 1 and 6 months after operation to check OTSC closure. Results Totally 23 patients were included into the study. The full-thickness resection rate of gastric tumors in the muscularis propria was 100 % (23/23), the success rate of defect closure was 100 %, and the average time of defect closure was 4.9 min (range 2–12 min). All patients experienced no postoperative complications such as bleeding and perforation. The postoperative follow-up time was 1–6 months (mean 3 months), and no OTSC detachment was found. Conclusions OTSC can be used to perform EFTR with defect closure for gastric tumors in the muscularis propria (tumor diameter ≤2 cm). It is simple, convenient, safe and effective. Electronic supplementary material The online version of this article (doi:10.1007/s00464-015-4076-2) contains supplementary material, which is available to authorized users.

The seismic ground motion hazard for Nepal has been estimated using a probabilistic approach. A catalogue of earthquakes has been compiled for Nepal and the surrounding region (latitude 26° N and 31.7° N and longitude 79° E and 90° E) from 1255 to 2011. The distribution of catalogued earthquakes, together with available geological and tectonic information were used to delineate twenty-three seismic source zones in Nepal and the surrounding region. By using the seismic source information and probabilistic earthquake hazard parameters in conjunction with a selected ground motion prediction relationship, peak ground accelerations (PGAs) have been calculated at bedrock level with 63%, 10%, and 2% probability of exceedance in 50 years. The estimated PGA values are in the range of 0.07–0.16 g, 0.21–0.62 g, and 0.38–1.1 g for 63%, 10%, and 2% probability of exceedance in 50 years, respectively. The resulting ground motion maps show different characteristics of PGA distribution, i.e., high hazard in the far-western and eastern sections, and low hazard in southern Nepal. The quantified PGA values at bedrock level provide information for microzonation studies in different parts of the country.

Pyrosine detection and quantification was reported by voltammetry with the electrochemically reduced graphene oxide (ERGO) modified glassy carbon electrode (GCE). The differential pulse voltammograms of pyrosine on the modified GCE showed that pyrosine can be sensitively detected, which may be attributed to the large surface area of ERGO and the improved electron transfer ability of ERGO compared to graphene oxide. The effect of supporting electrolyte and its concentration on the detection of pyrosine was also investigated in this paper. The ERGO modified GCE showed a linear concentration range between 1.6 and 374 μmol L−1 of pyrosine with a correlation coefficient of 0.9972, and the detection limit was as low as 1.2 × 10−8 mol L−1 (signal-to-noise ratio of 3).

NF-kappaB plays a critical role in cell survival, apoptosis, and inflammatory responses. Serine/threonine-specific phosphatases (PPs) represent the second major class of enzymes that catalyze the dephosphorylation of proteins. The roles of PPs regulating NF-kappaB activities are poorly understood. Here we describe an RNAi-based screen to identify the PPs that involve in regulating NF-kappaB signaling. Thirty-four candidate PPs siRNAs were synthesized and primarily screened by NF-kappaB reporter gene assay in HeLa cells. PHLPP, one of the protein phosphatase type 2C family members (PP2C), was identified as a positive regulator of NF-kappaB signaling. Knock-down of PHLPP dramatically attenuated TNFα-stimulated NF-kappaB transcriptional activation. Knockdown of PHLPP led to enhancement of NF-kappaB/p65 nuclear import and retention, but decreased TNFα-induced phosphorylation at Ser276 on p65. This critical phosphorylation was also drastically reduced by knock-down of PKCalpha and Akt1, two important serine/threonine kinases dephosphorylated by PHLPP. The results together suggest that PHLPP-Akt-PKC may represent an important signaling loop that activates NF-kappaB/p65 signaling through critical serine phosphorylation.

According to the distribution characteristics of short and repeated sequence (SRS), a steganalytic method based on the correlation of image bit planes is proposed. Firstly, we provide the conception of SRS distance statistics and deduce its statistical distribution. Because the SRS distance statistics can effectively reflect the correlation of the sequence, SRS has statistical features when the image bit plane sequence equals the image width. Using this characteristic, the steganalytic method is fulfilled by the distinct test of Poisson distribution. Experimental results show a good performance for detecting LSB matching steganographic method in still images. By the way, the proposed method is not designed for specific steganographic algorithms and has good generality.

Background Laparoscopic cholecystectomy (LC) has become the “gold standard” for treating symptomatic gallstones. Innovative methods, such as a scarless therapeutic procedure through a natural orifice are being introduced, and include transgastric or transcolonic endoscopic cholecystectomy. However, before clinical implementation, instruments still need modification, and a more convenient treatment is still needed. The aim of this study was to evaluate the feasibility of endoscopic internal gallbladder therapy such as cholecystolithotomy in an animal survival model. Methods Four pigs underwent endoscopic-ultrasound (EUS)-guided cholecystogastrostomy and the placement of a novel covered mental stent. Four weeks later the stents were removed and an endoscope was advanced into the gallbladder via the fistula, and cholecystolithotomy was performed. Two weeks later the pigs were sacrificed, and the healing of the fistulas was assessed. Results EUS-guided cholecystogastrostomy with mental stent deployment was successfully performed in all the animals. Four weeks after the procedure, the fistulas had formed and all the stents were removed. Endoscopic cholecystolithotomy was performed through each fistula. All the animals survived until they were sacrificed 2 weeks later. The fistulas were found to be completely healed. Conclusions This study reports the first endoscopic transmural cholecystolithotomy after placement of a novel mental stent in an animal survival model.