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In this study, we conducted two heat treatment processes, namely double aging (DA) and solid solution followed by double aging (SA), on the Inconel 718 alloy fabricated by selective laser melting (SLM). The aim was to investigate the microstructure evolution and mechanical properties of Inconel 718 under different heat treatment conditions. To achieve this, we employed advanced techniques such as Scanning Electron Microscope (SEM), electron backscattered diffraction (EBSD), energy dispersive spectroscopy (EDS), x-ray diffraction (XRD), Tofwerk time-of-flight secondary ion mass spectrometer (TOF-SIMS), and transmission electron microscopy (TEM). Our experimental findings reveal the presence of cellular high-density dislocation substructures in the as-received (AR) specimens, with a significant accumulation of Laves phase precipitates at grain boundaries and subgrain boundaries. After the DA treatment, the cellular substructure persists, with higher concentrations of γ" and γ' strengthened phases compared to AR specimen. Conversely, the SA specimen undergoes almost complete recrystallization, resulting in the dissolution of brittle Laves phases and a substantial increase in the content of strengthening phase γ" and γ'. As a consequence of the precipitation of the γ" and γ' strengthened phase and the modification of the microstructure, the material exhibits enhanced strength and hardness, albeit at the expense of reduced plasticity. The investigation of the relationship between heat treatment processes and precipitation behavior indicates that the SA heat treatment yields favorable mechanical properties that strike a balance between strength and plasticity. [ABSTRACT FROM AUTHOR]

Introduction: Recent studies report that latent tuberculosis infection (LTBI) may lead to an increased risk of cardiovascular disease (CVD) that led us to hypothesize that LTBI may play an important role in major adverse cardiovascular events (MACE) in dialysis patients. Methods: A single‐center retrospective cohort study was conducted. A total of 270 patients undergoing hemodialysis or peritoneal dialysis more than 3 months were included. The interferon enzyme‐linked immunospot (IFN‐γ ELISPOT) assay was used for the diagnosis of LTBI. Primary endpoints were MACE, including all‐cause death and acute coronary syndrome (ACS). The association between LTBI and MACE was examined using multivariate Cox proportional hazards regression after adjusting for covariates and Kaplan–Meier survival analysis. Results: In our study, the patients were classified into LTBI (n = 47) or non‐LTBI (n = 223) groups. Independent risk factors for LTBI in dialysis population were prior tuberculosis (TB) history (odds ratio [OR] 4.817 [1.064–22.306]), tobacco use (OR 2.903 [1.155–7.299]), and older age (OR 1.027 [1.002–1.053]). After a median follow‐up of 39 months, the incidence of active TB was 6.4% versus 0% in dialysis patients with and without LTBI, respectively (p = 0.005). Multivariate Cox analysis showed that LTBI was significantly associated with MACE (hazard ratio [HR] 2.540 [1.490–4.350]) after adjustment for potential confounders. Conclusions: Prior TB history, tobacco use, and the elderly can be used to select cost‐effective LTBI screening target groups in dialysis patients. LTBI is not only closely related to active TB but also an independent risk factor for higher incidence of MACE in dialysis population. [ABSTRACT FROM AUTHOR]

Helicobacter pylori is a highly prevalent pathogen in human gastric mucosa epithelial cells with strong colonization ability. Weizmannia coagulans is a kind of active microorganism that is beneficial to the improvement of host gut microbiota balance and can prevent and treat intestinal diseases. We investigated the beneficial effects of W. coagulans BC99 in H. pylori infected mice and measured inflammation response, oxidative stress, and gut microbiota. Results showed that BC99 could alleviate the gastric inflammation, inhibit the increasing of inflammation parameters endotoxin, interleukin‐10, transforming growth factor‐β, and interferon‐γ and oxidative stress myeloperoxidase and malondialdehyde, promote the levels of superoxide dismutase and catalase. Furthermore, 16S rRNA gene sequencing analysis revealed that BC99 reversed the change of gut microbiota by reducing the abundance of Olsenella, Candidatus_Saccharimonas, Monoglobus, and increasing the abundance of Tyzzerella. Meanwhile, BC99 caused elevated levels of Ligilactobacillus and Lactobacillus. In view of the beneficial effect of BC99 on the content of short‐chain fatty acid, valeric acid with sodium valerate interfered with H. pylori infection in mice found that valeric acid had a good restorative effect of H. pylori infection relating inflammation and oxidative stress responses. These results suggest that W. coagulans BC99 can be used as a potential probiotic to prevent and treat H. pylori infection by regulating the inflammation, oxidative stress, and gut microbiota. [ABSTRACT FROM AUTHOR]

Multiple gene knockouts are often employed in studies of microbial physiology and genetics. However, the selective markers that confer antibiotic resistance are generally limited, so it is necessary to remove these resistance genes before the next round of using, which is time consuming and labor intensive. Here, we created a universal circular gene knockout system for both the gram-negative bacterial Burkholderiales strain DSM 7029 and the gram-positive bacterial Mycobacterium smegmatis mc2 155, by combining the homologous recombination with multiple serine integrase-meditated site-specific recombination systems. In this system, a resistance gene and an integrase gene were constructed within the two attachment sites corresponding to a second, different integrase to form a cassette for gene disruption, which could be easily removed by the second integrase during the subsequent round of gene knockout. The sacB gene was also employed for negative selection. As the integrase-mediated deletion of the resistance/integrase gene cassette was highly efficient and concurrent with the following knockout round, the cyclic use of three cassettes could achieve multiple gene knockout in a sequential manner. Following the modularity concept in synthetic biology, common components of the knockout plasmids were retained as BioBricks, accelerating the knockout plasmids construction process. The circular gene knockout system can also be used for multiple gene insertions and applied to other microorganisms., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)