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Concrete produced by 3D printing has been widely studied, however, most studies focus on the static properties of 3D printed materials, but few on dynamic properties. In this study, the dynamic properties of 3D printed cement mortar were evaluated from the dynamic compressive strength, energy dissipation density, failure modes, fragment distribution, and fractal dimension. In the strain rate range of 70 s−1-140 s−1, the anisotropy of dynamic compressive strength diminishes with increasing strain rate, but remains more significant than the anisotropy of static compressive strength. Acoustic indices were used to evaluate the anisotropy of the dynamic compressive strength of 3D printed cement mortar, revealing an exponential relationship between ultrasonic pulse velocity (UPV) and dynamic compressive strength. The energy dissipation density under the same strain rate varies in three key printing directions. Finally, the number of main cracks is different in three printing directions in the failure process under the same strain rate, which leads to different degrees of damage, and thus different fragment distributions and fractal dimensions therein. [ABSTRACT FROM AUTHOR]

Background: Deoxynivalenol (DON) is a widespread issue for feed and food safety, leading to animal and human health risks. The objective of this study was to determine whether ferroptosis is involved in DON-induced intestinal injury in piglets. Three groups of 21-day-old male weanling piglets (n = 7/group) were fed a control diet, or diet adding 1.0 or 3.0 mg DON/kg. At week 4, serum and small intestines were collected to assay for biochemistry, histology, redox status and ferroptosis-related genes expression. In addition, the involvement of ferroptosis and the role of FTL gene in DON-induced cell death were further verified in the IPEC-J2 cells. Results: Compared to the control, dietary supplementation of DON at 1.0 and 3.0 mg/kg induced different degrees of damage in the duodenum, jejunum and ileum, and increased (P < 0.05) serum lipopolysaccharide concentration by 46.2%–51.4%. Dietary DON supplementation at 1.0 and (or) 3.0 mg/kg increased (P < 0.05) concentrations of malondialdehyde (17.4%–86.5%) and protein carbonyl by 33.1%–92.3% in the duodenum, jejunum and ileum. In addition, dietary supplemented with DON upregulated (P < 0.05) ferroptotic gene (DMT1) and anti-ferroptotic genes (FTL and FTH1), while downregulated (P < 0.05) anti-ferroptotic genes (FPN, FSP1 and CISD1) in the duodenum of the porcine. Furthermore, the in vitro study has demonstrated that deferiprone, a potent ferroptotic inhibitor, mitigated (P < 0.05) DON-induced cytotoxicity in porcine small intestinal IPEC-J2 cells. Additionally, deferiprone prevented or alleviated (P < 0.05) the dysregulation of ferroptosis-related genes (ACSL4 and FTL) by DON in IPEC-J2 cells. Moreover, specific siRNA knockdown FTL gene expression compromised the DON-induced cell death in IPEC-J2 cells. Conclusions: In conclusion, this study revealed that ferroptosis is involved in DON-induced intestinal damage in porcine, and sheds a new light on the toxicity of DON to piglets. [ABSTRACT FROM AUTHOR]

Comparing with the traditional construction process, 3D printing technology used in construction offers many advantages due to the elimination of formwork. Currently, 3D printing technology used in the construction field is widely studied, however, limited studies are available on the dynamic properties of 3D printed materials. In this study, the effects of sand to binder ratios and printing directions on the fractal characteristics, dynamic compressive strength, and energy dissipation density of 3D printed cement mortar (3DPCM) are explored. The experiment results indicate that the printing direction has a more significant influence on the fractal dimension compared with the sand to binder ratio (S/B). The increasing S/B first causes an increase and then results in a decline in the dynamic compressive strength and energy dissipation of different printing directions. The anisotropic coefficient of 3DPCM first is decreased by 20.67%, then is increased by 10.56% as the S/B increases from 0.8 to 1.4, showing that the anisotropy is first mitigated, then increased. For the same case of S/B, the dynamic compressive strength and energy dissipation are strongly dependent on the printing direction, which are the largest printing in the Y-direction and the smallest printing in the X-direction. Moreover, the fractal dimension has certain relationships with the dynamic compressive strength and energy dissipation density. When the fractal dimension changes from 2.0 to 2.4, it shows a quadratic relationship with the dynamic compressive strength and a logarithmic relationship with the energy dissipation density in different printing directions. Finally, the printing mortar with an S/B = 1.1 is proved to have the best dynamic properties, and is selected for the 3D printing of the designed field barrack model. [ABSTRACT FROM AUTHOR]

Recently, microbially induced carbonate precipitation (MICP) has been studied as an alternative for the improvement of sand–clay mixtures. However, the cementing uniformity of MICP-treated sand–clay mixtures cannot be guaranteed. In this present study, enzymatic-induced carbonate precipitation (EICP) was used to deal with it. The ions used in kaolin clay was predicted to affect the production rate for calcium carbonate (CaCO3), which was studied using the calcification test. The solidification test was conducted using two different methods (the premixing method and the diffusion method). The permeability, unconfined compressive strength and the content of CaCO3 of treated samples were obtained to evaluate the solidification effect of the EICP method. Moreover, in EICP treatment, the particle aggregation decreased the liquid limit, but the addition of solution increased it. Therefore, there were contrary effects to the soil consistency. In this study, the two types of liquid limits of treated samples were measured with deionized water and 2M-NaCl brine, respectively. The results show that the Al2O3, NaCl and MgCl2 in the kaolin clay had a slight impact on the production rate for CaCO3, while FeCl3 significantly inhibited it. The EICP method can improve sand–clay mixtures and decrease their permeability. Different from MICP, the EICP method can guarantee the uniformity of treated samples. Moreover, the liquid limit of the sample treated with the premixing method decreased, while that of the sample treated with the diffusion method increased firstly and then decreased with the increasing treatment cycles. Different from the deionized water, the pore-fluid chemistry had a larger effect on the liquid limit with 2M-NaCl brine. [ABSTRACT FROM AUTHOR]

Fresh vegetables are closely associated with foodborne disease outbreaks; however, systematic analysis of the microbiological quality of fresh vegetables and molecular information on foodborne pathogens in fresh produce are poorly reported in China. Here, we evaluated the epidemiological prevalence of coliforms via the most probable number method and characterized Salmonella and ciprofloxacin-resistant (CIPR) Escherichia coli isolates recovered from retail fresh vegetables in Shaanxi Province, China. Antimicrobial susceptibility testing, serotype determination, multilocus sequence typing (MLST), core genome multilocus sequence typing (cgMLST), antibiotic resistance encoding gene (ARG) annotation, virulence factor prediction, and functional classification were performed. Between October 2020 and September 2021, 576 samples (i.e., tomatoes, lettuces, spinaches, and cabbages) were found to be positive for coliforms, and the prevalence of coliforms showed a seasonal trend. Coliform counts of vegetables in supermarkets in Xi'an were significantly lower (P < 0.01) than that in other cities. The detection rates of Salmonella and CIPR E. coli -positive vegetables were 1 % (6/576) and 0.7 % (4/576), respectively. All isolates exhibited resistance to ≥1 antibiotics, and 92.9 % (13/14) were multidrug-resistant. One extended spectrum β-lactamase (ESBL)-producing CIPR E. coli isolate in spinach was resistant to not only three third-generation cephalosporins but also to two polymyxins. Among nine Salmonella isolates, five different serovars (S. Enteritidis , S. Indiana , monophasic variant of S. Typhimurium , S. Agona, and S. Gallinarum), four sequence types (STs; ST11, ST13, ST17, and ST34), and seven core genome STs (cgSTs) were identified. Five CIPR E. coli strains were assigned to three serovars (O101:H4, O8:H18, and O11:H25), three STs (ST44, ST48, and ST457), and four cgSTs. Coexisting amino acid mutations of Thr57Ser/Ser80Arg in ParC and Ser83Phe/Asp87Gly in GyrA in quinolone resistance-determining regions (QRDRs) might be causes for nalidixic acid resistance. Eight definite virulence profiles in eight serovars were identified. Notably, cdtB and pltA only encoded typhoid toxins and were just detected from S. Typhoid isolates were also detected from S. Indiana and monophasic S. Typhimurium , which are closely associated with swine food chain were first detected in fresh vegetables. In conclusion, our findings suggest that coliform contamination on fresh vegetables is prevalent in this province. Most Salmonella and CIPR E. coli isolates were phenotypically and genetically diverse and could resist multiple antibiotics by carrying multiple ARGs and virulence genes. [Display omitted] • All fresh vegetables were positive for coliforms with high level. • 5 serovars, 4 STs and 7 cgSTs were identified from 9 Salmonella isolates. • 3 serovars, 3 STs and 4 cgSTs were identified from 5 CIPR E. coli isolates. • Monophasic S. Typhimurium is firstly identified from fresh vegetables. • Typhoid-associated virulence genes, cdtB and pltA were detected. [ABSTRACT FROM AUTHOR]

Occupant activity (OA) is a crucial prerequisite for providing energy-efficient and occupant-centric services in intelligent buildings. To understand OAs well, conventional technologies require either wearable equipment of smart devices or the deployment of specialized cameras, raising relevant issues of body and privacy-intrusion. Recent WiFi-based methods circumvent the above issues and characterize the OA patterns in a non-intrusive manner. However, they demand the cooperation of occupants for a sufficient amount of collected samples, otherwise, the performance might degrade significantly. In this paper, we propose a non-intrusive approach that models distinct OA patterns for comprehensive understanding. Based on the idea of generative adversarial network (GAN), our technical novelties are three-fold. First, we modify the working principle of vanilla GAN with external constraints to avoid brute-force generation. Second, we integrate a self-attention mechanism to establish contextual relations from both local and global perspectives. Third, to recover the informative details, we construct a powerful generator with deep residual convolutional operations. We conduct extensive experiments on a real dataset and visualize the generation results for intuitive evaluation. Numerical results compared with several state-of-the-art baselines further illustrate the superior performance of our proposed GAN approach. [ABSTRACT FROM AUTHOR]