Milk fat globule membrane protects Bifidobacterium longum ssp. infantis ATCC 15697 against bile stress by modifying global transcriptional responses.

The milk fat globule membrane (MFGM) can protect probiotic bacteria from bile stress. However, its potential mechanism has not been reported. In this study, the viability, morphology and gene transcriptional response of Bifidobacterium longum ssp. infantis ATCC 15697 (BI_15697) stressed by bile salts with or without MFGM were investigated. It was shown that MFGM alleviated the reduction in BI_15697 population induced by 0.2% porcine bile stress and restored the population to the control levels. MFGM ameliorated the shrunken, fragmented appearance and irregular morphology of BI_15697 and maintained cell integrity disrupted by bile stress. RNA-sequencing results showed that MFGM increased transport of glucose and raffinose and decreased that of branched-chain amino acids (BCAA) in the presence of bile salts. MFGM stimulated the expression of genes involved in the synthesis of raffinose in galactose metabolism and the metabolism of BCAA, suggesting that MFGM stimulated the accumulation of raffinose and BCAA in the presence of bile. In addition, MFGM stimulated the expression of 2 bile efflux transporters under bile stress. Together, the multifactorial response helps BI_15697 excrete bile salts and maintain cellular integrity in response to bile stress. This study proposes a mechanism for the protection of BI_15697 against bile salt stress by MFGM, thereby providing a molecular basis for its application in incorporation of probiotics.

Screening of Bifidobacteria with Probiotic Potential from Healthy Infant Feces by Using 2'-Fucosyllactose.

Using 2'-fucosyllactose (2'-FL) as the sole carbon source can be an efficient way to screen bifidobacteria with superior probiotic capabilities since 2'-FL is a key element in promoting the growth of intestinal bifidobacteria in newborns. This approach was used in this work to screen eight bifidobacteria strains, including one strain of Bifidobacterium longum subsp. infantis BI_Y46 and seven strains of Bifidobacterium bifidum (BB_Y10, BB_Y30, BB_Y39, BB_S40, BB_H4, BB_H5 and BB_H22). Studies on their probiotic properties showed that BI_Y46 had a unique morphology with pilus-like structure, a high resistance to bile salt stimulation and a potent inhibitory action on Escherichia coli ATCC 25922. Similarly, BB_H5 and BB_H22 produced more extracellular polysaccharides and had a higher protein content than other strains. In contrast, BB_Y22 displayed considerable auto-aggregation activity and a high resistance to bile salt stimulation. Interestingly, BB_Y39 with weak self-aggregation ability and acid resistance had very excellent bile salt tolerance, extracellular polysaccharides (EPS) production and bacteriostatic ability. In conclusion, 2'-FL was used as sole carbon source to identify eight bifidobacteria with excellent probiotic properties.

First-principles Investigations of Magnetic Semiconductors: An example of Transition Metal Decorated Two-dimensional SnS Monolayer.

The absence of magnetic moments in pristine two-dimensional (2D) semiconducting materials has attracted many research interests. Transition-metal (TM) decoration has been found to be an effective strategy to introduce magnetic moments in non-magnetic 2D semiconductors. However, the stability of TM atoms modified 2D semiconductors has not been well explored. Here, taking 2D Tin (II) sulfide (SnS) monolayer as a prototype, we explored the stability of magnetic semiconductors through this method. In our studies, all possible configurations of TM decoration have been considered, namely, adsorption on the intact surface, S vacancy, and Sn vacancy. Based on the energy gain and electronic analysis, our results revealed that most of the TM atoms will form a cluster, and only several TM atoms can be effectively doped into the SnS monolayer. Furthermore, the band calculations showed that only Mn substitution will give rise to a magnetic semiconductor. Thus, the reported results here provide some hidden information for further realization of the magnetic semiconductors and serve as a paradigm to prepare 2D magnetic semiconductors.

[Surgical treatment of constrictive pericarditis: experience in 72 cases].

Our experience with the surgical treatment of constrictive pericarditis in 72 cases is reported. The patients receiving surgical treatment had their cardiac function improved to NYHA class I in 59 cases and class II in 11 cases, and death occurred during the operation in 1 case and after the operation in another case due to myocardial expansion and low cardiac output syndrome, respectively. The key elements to ensure success of the surgeries lie in the extent of pericardiectomy and the time and approaches chosen for the operation.