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Inflammatory bowel disease (IBD), encompassing ulcerative colitis (UC) and Crohn's disease (CD), arises from intricate interactions involving genetics, environment, and pharmaceuticals with an ambiguous pathogenic mechanism. Recently, there has been an increasing utilization of lactic acid bacteria (LAB) in managing IBD, attributed to their ability to enhance intestinal barrier function, mitigate inflammatory responses, and modulate gut microbiota. This review initiates by elucidating the pathogenesis of IBD and its determinants, followed by an exploration of the mechanisms underlying LAB therapy in UC and CD. Special attention is directed towards their influence on intestinal barrier function and homeostasis regulated by gut microbiota. Furthermore, the review investigates the complex interplay among pivotal gut microbiota, metabolites, and pathways associated with inflammation. Moreover, it underscores the limitations of LAB in treating IBD, particularly in light of their varying roles in UC and CD. This comprehensive analysis endeavors to offer insights for the optimized application of LAB in IBD therapy. [ABSTRACT FROM AUTHOR]

Simple Summary: The actin-related protein complex 2/3 complex (Arp2/3) is a kind of actin regulatory protein that regulates the nucleation, aggregation and assembly of F-actin. In recent years, there have been reports at home and abroad about the effects of the Arp2/3 complex on oocyte maturation of mammals such as pigs and mice, but few studies are about its effects on goats. In present study we showed that the Arp2/3 complex is necessary for the maintenance of cytoskeletal meiotic dynamics, such as F-actin assembly and spindle organization in goat oocytes. Additionally, these cytoskeletal dynamics are essential for the regulation of mitochondrial distribution and function, including mitochondrial activity and redox homeostasis, which are critical for the meiotic maturation of goat oocytes. F-actin is of critical importance in oocyte meiotic maturation. Actin assembly and its dynamics are mainly regulated by actin nucleation factors. The actin-related protein complex 2/3 (Arp2/3) is responsible for the organization of F-actin filaments. However, the role of Arp2/3 complex in goat oocytes has not been fully elucidated. Our findings demonstrate that Arp2/3 complex activity is necessary for the maturation of goat oocytes. The Arp2/3 complex-specific inhibitor CK666 impairs the maturation of goat oocytes and alters the genes associated with cumulus expansion, both of which suggest that normal meiosis is affected. Arp2, one of the subunits of the Arp2/3 complex, was found to be mainly accumulated at the oocyte cortex and to co-localize with F-actin during goat oocyte maturation in our results. Thus, we further investigated the cytoskeleton dynamics and found that Arp2/3 complex inhibition disrupts the F-actin assembly and spindle organization. Further analysis revealed that, in addition to direct effects on the cytoskeleton, Arp2/3 complex could also induce ROS accumulation and oxidative stress by disrupting mitochondrial distribution and function, ultimately increasing the rate of early apoptosis in goat oocytes. Our study provides evidence that the Arp2/3 complex is a key regulator of goat oocyte maturation through its regulation of the cytoskeleton dynamics and mitochondrial function. [ABSTRACT FROM AUTHOR]

Two single track multi-layer walls with linear energy inputs (LEIs) of 219 and 590 J/mm were deposited by cold metal transfer-based wire arc additive manufacturing system. Combined with the X-ray diffraction technique, scanning electron microscope and uniaxial tensile tests, the influences of LEI and cooling rate (CR) on the microstructure evolution, mechanical properties and fracture mechanisms of the studied steel are analyzed. It is observed that the microstructures of the studied steel are mainly composed of δ-ferrite and austenite dendrites. σ phase is formed on the δferrite–austenite interface under low CR. Meanwhile, the primary dendrites' spacing decreases with the decrease in LEI or the increase in CR, and the maximal primary dendrites' spacing is 32 μm. The values of elongation to fracture roughly decline with the decrease in LEI or the increase in CR, but the variations of ultimate tensile strength and yield stress show an opposite trend. In addition, the mesoscopic damages in the studied steel under low LEI are mainly caused by the coalescence of pores. While under high LEI, the cracks are induced by the dislocations piling up around δ-ferrite. [ABSTRACT FROM AUTHOR]

The effects of linear heat input (LHI) on the microstructure and corrosion behavior of an austenitic stainless steel processed by wire arc additive manufacturing (WAAM) are studied. It is found that the primary dendrites spacing of the studied steel increases from 18 μm to 23 μm, when the LHI increases from 219 J ⋅ mm - 1 to 590 J ⋅ mm - 1 . But the δ-ferrite contents under high and low LHIs are similar. Moreover, the passivation voltage range decreases and the corrosion current density increases with the increase of LHI. The poor corrosion resistance for the studied steel under high LHI is highly related with the segregation of Cr and Mo atoms in the Ni-poor δ-ferrite. • The effect of linear heat input on a stainless steel processed by WAAM is studied. • The primary dendrites grow quickly during the WAAM under high linear heat input. • The poor corrosion property is related with the segregation of Cr/Mo in δ-ferrite. [ABSTRACT FROM AUTHOR]

The hot tensile deformation and fracture behaviors of a typical ultrahigh strength steel are investigated by isothermal uniaxial tensile experiments over the tensile temperatures of 900–1150 °C and strain rates of 0.01–10 s - 1 . By combining the results of tensile tests and microstructural observation, the effects of deformation processing parameter (strain rate and tensile temperature) on the macroscopic plastic deformation behaviors, microscopic fracture morphologies and microstructural evolution are clarified. The studies indicate that the hot tensile behavior of the studied steel is greatly influenced by the competition of damage evolution, work hardening, and dynamic softening. With the increased strain rate, the strain rate sensitivity coefficients decrease, but the value of elongation to fracture increase from 0.38 to 0.50. The variations of microvoids or cracks in amounts and sizes show an increasing trend with the increased strain rate or the decreased tensile temperature. At the low tensile temperature (900 °C), the poor capability of necking diffusion hardly prevents the strain localization, and the mesoscopic damages easily take place. As the strain rate increases from 0.01 to 10 s - 1 , the neat fracture morphologies gradually change to the serrated. The main ductile fracture mechanisms transform from the intergranular fracture at the high tensile temperature and low strain rate to the transgranular fracture at the low tensile temperature and high strain rate. • The hot tensile deformation and fracture behaviors of a typical ultrahigh strength steel are studied. • With the increased strain rate, the strain rate sensitivity coefficient decreases, but the elongation to fracture increases. • The main fracture mechanisms transform from the intergranular to transgranular fracture with the decreased tensile temperature. [ABSTRACT FROM AUTHOR]

AbstractHypoxia is an important characteristic of Tibetan plateau environment. It can lead to apoptosis, but the mechanism of apoptosis caused by hypoxic stress needs further clarification. Here, cattle kidney cell MDBK were used as cell model. The effect of hypoxic stress on apoptosis and its molecular mechanism were explored. MDBK cells were treated with hypoxic stress, apoptosis and mitochondrial apoptotic pathway were significantly increased, and the expression of B-cell lymphoma 6 (BCL6) was significantly decreased. Overexpressing or inhibiting BCL6 demonstrated that BCL6 inhibited the apoptosis. And the increase of apoptosis controlled by hypoxic stress was blocked by BCL6 overexpressing. MDBK cells were treated with hypoxic stress, the expression and the nuclear localization of p53 were significantly increased. Overexpressing or inhibiting p53 demonstrated that hypoxic stress suppressed the expression of BCL6 through p53. Together, these results indicated that hypoxic stress induced the apoptosis of MDBK cells, and BCL6 was an important negative factor for this regulation process. In MDBK cells, hypoxic stress suppressed the expression of BCL6 through p53/BCL6-mitochondrial apoptotic pathway. This study enhanced current understanding of the molecular mechanisms underlying the regulation of apoptosis by hypoxic stress in MDBK cells. [ABSTRACT FROM AUTHOR]

The metadynamic recrystallization (MDRX) behaviors and microstructure evolution of 300 M steel are studied by hot compression experiments and high temperature laser scanning confocal microscopy (HTLSCM) experiments. The effects of insulation temperature, pre-strain rate and holding time on the MDRX behaviors are discussed in detail. Based on the statistical results of the microstructure evolution, the MDRX kinetics model and recrystallization (RX) grain size model of 300 M steel are established, respectively. It can be confirmed from the in-situ observations that strain-induced boundary migration mechanism and curvature-driven grain boundary migration mechanism are the main MDRX mechanisms of 300 M steel. The MDRX develops rapidly under the high temperature or low pre-strain rate. The insulation temperature has a more important effect on the MDRX rate. The RX grain size increases with the increased insulation temperature, pre-strain rate and holding time. Compared to the pre-strain rate, the effects of insulation temperature on the maximum MDRX fraction and RX grain size are negligible. Comparisons between the experimental and predicted results verify that the proposed MDRX kinetics models and RX grain size model can quantificationally reveal the MDRX behaviors of 300 M steel well. • The MDRX behaviors are investigated by hot compression experiments and HTLSCM experiments. • The MDRX mechanisms are mainly strain-induced boundary migration and curvature-driven grain boundary migration. • The models for MDRX kinetics and RX grain size are established based on the statistic results of microstructure. • Insulation temperature affects MDRX rate obviously, while pre-strain rate affects maximum MDRX fraction apparently. [ABSTRACT FROM AUTHOR]