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The increasing incidence of multidrug-resistant (MDR) Salmonella enterica serovar Typhimurium (S. Tm), known for causing invasive enteric infections, presents a significant public health challenge. Given the diminishing efficacy of existing antibiotics, it is imperative to explore novel alternatives for the treatment of MDR S. Tm infections. Here, we identified esculetin (EST), a natural coumarin abundant in dietary foods and herbs, as a compound exhibiting broad-spectrum antibacterial properties against a range of MDR bacteria. Our findings demonstrate that EST effectively inhibited the proliferation and expansion of MDR S. Tm in both in vitro experiments and animal models. Specifically, EST significantly downregulated the type 3 secretion system-1 (T3SS-1) virulence expression of MDR S. Tm, thereby preventing its invasion into intestinal epithelial cells. In S. Tm-infected mice, we observed cecal injury characterized by the upregulation of inflammatory cytokines, a reduction in goblet cell numbers, a decreased expression of tight junction proteins, and microbial dysbiosis. Conversely, EST treatment ameliorated these pathological changes induced by S. Tm infection and reduced oxidative stress by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, thereby improving intestinal barrier function. These results suggest that dietary coumarins or a targeted plant-based diet may offer a promising strategy to counteract MDR bacteria-induced enteric diseases. [ABSTRACT FROM AUTHOR]

Multileg roundabout intersections are widely used in urban areas worldwide. However, its traffic organization and signal control are very complicated in the case of large traffic flow, and the signal optimization methods for conventional intersections are not suitable for applying directly to roundabouts due to the complexity of the operating process. Therefore, many scholars have focused on dedicated signal timing schemes for roundabouts, especially through tuning key parameters such as signal cycle and green light time. However, research and applications regarding variable phases at roundabouts are quite rare. To address this gap, this paper analyzes the traffic flow characteristics and capacity of multileg roundabouts and proposed a combined phase design model to achieve the maximum utilization of road capacity at roundabouts, which can generate the optimal phase scheme based on real-time traffic data. The feasibility of the combined phase design model is verified by a case study in Jinhua, China. The results indicate that the proposed combined phase design model can improve the applicability of actuated signal control and the reasonableness of signal timing for multileg roundabouts and thus further improve the roundabout efficiency., Author(s): Chengyuan Mao (corresponding author) [1]; Qin Wang [1]; Wenjiao Xu [1]; Xin Cheng [1]; Shengde Yang [1]; Peiran Li [1] 1. Introduction A roundabout is one of the most [...]

For decades, distiller waste and CO2 were not the first choice for production of high valued products. Here, CaCO3 hollow microspheres, a high-value product was synthesized from such a reaction system. The synthetic methods, the formation mechanism and operational cost were discussed. When 2.5 L·min−1·L−1 CO2 was flowed into distiller waste (pH = 11.4), spheres with 4–13 diameters and about 2 shell thickness were obtained. It is found that there is a transformation of CaCO3 particles from solid-cubic nuclei to hollow spheres. Firstly, the Ca(OH)2 in the distiller waste stimulated the nucleation of calcite with a non-template effect and further maintained the calcite form and prevented the formation of vaterite. Therefore, in absence of auxiliaries, the formation of hollow structures mainly depended on the growth and aging of CaCO3. Studies on the crystal morphology and its changes during the growth process point to the inside-out Ostwald effect in the formation of hollow spheres. Change in chemical properties of the bulk solution caused changes in interfacial tension and interfacial energy, which promoted the morphological transformation of CaCO3 particles from cubic calcite to spherical clusters. Finally, the flow process for absorption of CO2 by distiller waste was designed and found profitable. [ABSTRACT FROM AUTHOR]

A novel crawling in-pipe robot was designed to improve the adaptive ability with self-locking principle applied. In the moving, the robot was adaptable to horizontal, vertical and bending pipes with different diameters and sections without exerting additional pressure to the shell. The robot used a telescopic umbrella stand as a basic structure. The force of telescopic mechanism, self-locking principle of supporting mechani sm and shell were deduced from design requirements. The design of supporting and coupling mechanism was completed. The relationship between screw rod thrust and parallelogram driving force was established. A prototype was made and tested according to the suggested design methods. The results show that the robot with powerful traction, good self-locking performance and smooth passage through curve can move forward in the pipe with 90~150 mm inner diameter.

In this paper, an ultra-light and high electromagnetic shielding effectiveness (SE) composite material based on melamine foam with its skeleton metallized was prepared via electroless silver plating techniques. Salt-based colloid palladium was applied as the activator to modify the foam skeleton. X-ray photoelectron spectroscopy was used for tracking the Pd activated process. The effects of silver plating time, dynamic and static electroless plating conditions on the surface morphology, electrical and EMI shielding properties were investigated. The silver content in the foams subjected to electroless plating for different time was measured by thermo gravimetric analysis. Crystal structure of the silver nanoparticles was examined by the X-ray diffraction (XRD). Results show that a dense, uniform, consecutive silver layer forms on the surface of foam skeleton with the electroless silver plating time increases. A relatively dynamic electroless plating conditions do not help to construct a complete silver layer without cracks. The conductivity and SE of the foams is enhanced with the extension of silver plating time. The foam just containing 63.5 wt% silver achieves a minimum resistivity of 0.06 Ω cm and a SE of above 90 dB at the frequency range of 0.05-18 GHz. The foam prepared under a dynamic electroless plating condition exhibits lower SE than that under a static electroless plating condition. The XRD pattern shows the deposited silver coating exists as a typical face-centered cubic crystalline structure and the average crystal size is 14.4 nm. All results imply that such conductive melamine foam exhibits excellent electrical and EMI shielding properties, which can be used in a broad application range. [ABSTRACT FROM AUTHOR]

Objective: This research seeks to ascertain the prevalence and determinants of mirror-image dextrocardia in fetuses., Study Design: With December 2022 as the reference point, we compiled colleted data on pregnant women who carried fetuses with mirror-image dextrocardia in Xi'an, Shaanxi Province: September-October 2022, November 2022, and December 2022-January 2023. An online questionnaire was distributed to 209 pregnant across China who had contracted COVID-19. The case group comprised women whose final menstrual cycle occurred in November 2022 and who had a fetus with mirror-image dextrocardia. Women with a November 2022 final menstrual period and a fetus without this condition made up the control group. To identify the risk factors associated with fetal mirror-image dextrocardia, both univariate and multivariate logistic regression analyses were employed., Results: A significant difference was noted in the gestational age at COVID-19 infection women with a September to October 2022 and December 2022 to January 2023 final menstrual period who did not bear a fetus with mirror-image dextrocardia, and those with a November 2022 final menstrual period whose fetus exhibited this condition. The univariate and multivariate analyses conducted on pregnant women with a final menstrual period in November 2022 who had contracted COVID-19 revealed significant differences in the presence and duration of fever between those bearing fetuses with mirror-image dextrocardia and those without ( P = 0.000)., Conclusion: The findings suggest two critical factors to the increased prevalence of fetal mirror-image dextrocardia: 1) the infection timing which occurs between the 4th and 6th week of pregnancy and 2) the presence of fever and its prolonged duration.

Objective To investigate whether vitamin D3 (VD3) can alleviate Helicobacter pylori (Hp) infection by reducing blood lipids and inhibiting the Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) signaling pathway. Methods High-cholesterol mouse model and Hp infected mouse model were established. Each was treated with VD3 via oral administration for 8 weeks. Real-time quantitative PCR was used to detect the expression of vitamin D receptor (VDR), insulin-induced gene 2 (Insig-2), and gastrin mRNA. Western blot analysis was used to examine the expression of JAK, STAT3, and cyclooxygenase-2 (COX2) proteins in gastric tissues. Biochemical analyses were performed to measure serum cholesterol levels, and ELISA was utilized to evaluate serum gastrin, interleukin 6 (IL-6), and IL-8 levels, along with histopathological examination of liver and gastric tissues using HE staining. Results After oral administration of VD3, the levels of VDR and Insig-2 in mouse liver tissue significantly increased in the high cholesterol group and the high cholesterol combined with Hp infection group. And the expression of serum gastrin decreased. The expression of JAK, STAT3 in gastric tissues reduced, as did the expression of COX2. Serum cholesterol levels decreased, with no significant changes in IL-6 levels, but a reduction in IL-8 levels. Compared to the control group, the high cholesterol combined with Hp infection group showed reduced hepatic ballooning degeneration and alleviated gastric tissue inflammation. In addition, inflammation in gastric tissue was also reduced in the cholesterol group and the Hp infection group. Conclusion VD3 alleviates gastritis by enhancing the activity of VDR in liver tissues, blocking the JAK/STAT3 signaling pathway, and inhibiting the expression of inflammatory factors.

Objective: To investigate the effects of equal concentration of Helicobacter pylori suspension on gastric mucosal infection in mice by different gavage methods. 
 Methods: Six-week-old male C57BL/6 mice were infected by a suspension of Brucella broth containing the same amount of NCTC11637 Helicobacter pylori suspension by A, B, C, and D methods. For method A, the mice were intragastrically administered with Helicobacter pylori suspension (0.2 mL per mouse), once two day for 5 times; for method B, the mice were intragastrically administered with Helicobacter pylori (0.2 mL per mouse) once a day for 5 times; for method C, the mice were perfused with 0.4 mL per mouse of Helicobacter pylori suspension on the first day, then once a day and 0.2 mL per mouse for 3 times; for method D, the mice were administrated with 0.4 mL per mouse Helicobacter pylori suspension on the first day, 0.2 mL per mouse every other day for 3 times. For method E, the mice received equal amounts of normal saline. The mice were killed at 2, 4, and 6 weeks after gavage. The gastric mucosa was detected by rapid urease test for Helicobacter pylori infection, and gastric mucosa was taken for HE staining to observe the degree of infection.
 Results: After 2 weeks of gavage, the infection rates of the mice in A, B, C, and D group were 33.3%, 50.0%, 66.7%, and 33.3%, respectively. The degree of inflammation infection was as following order: C group>B group>D group>A group>E group. The infection rates of mice after 4 weeks of gavage in the A, B, C, and D groups were 50.0%, 83.3%, 83.3%, and 66.7%, respectively. The degree of inflammation infection was as following order: C group>B group>D group>A group>E group. After 6 weeks of gavage, the infection rate in A, B, C, and D groups was 100%, while the degree of inflammation infection was as following order: C group>D group>B group>A group>E group.
 Conclusion: At the acute stage of Helicobacter pylori infection, different gavage methods show different infection rates in mice, and the degree of inflammation is different. At the chronic stage, different gavage methods display the same infection rate in mice with different degree. The gavage method that 0.4 mL Helicobacter pylori suspension on the first day, then once a day and 0.2 mL for 3 times is most conducive to Helicobacter pylori colonization in the gastric mucosa of mice. This method can induce the the most seriou inflammatory infection and is beneficial to the successful establishment of the Helicobacter pylori infection model.