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N,N‐diacetyllactosamine (LacdiNAc) is a motif present in various glycoconjugates of animal cell surfaces. The enzymatic synthesis of the LacdiNAc motif was previously achieved by using mutant variants of the human and bovine β1,4‐galactosyltransferase 1 (β1,4‐GalT1, EC 2.4.1.38). These enzymes bear a specific tyrosine to leucine substitution, which enables the transfer of GalNAc from UDP‐GalNAc. Herein, we present that the same tyrosine to leucine substitution in recombinant β1,4‐GalT1 orthologues of mouse, rat, or pig also resulted in the complete shift of the glycosyl donor specificity from UDP‐galactose to UDP‐GalNAc. In addition, we tested a previously undescribed β1,4‐GalT1 orthologue from C. elegans (CeGalT1). Given that this enzyme possesses an isoleucine residue in the wild‐type variant, this enzyme should prefer UDP‐GalNAc as a glycosyl donor substrate. Surprisingly, CeGalT1 was strictly specific for UDP‐Gal, but an isoleucine to tyrosine mutant variant of CeGalT1 widened the substrate range towards UDP‐GalNAc. In addition, the CeGalT1 mutant variant showed also significantly improved enzymatic activity towards UDP‐Gal. To further investigate the role of this tyrosine to leucine substitution of β1,4‐GalT1 and to evaluate the potential of this mutation for biotechnological applications, we generated Tyr286Leu B4galt1 mice using CRISPR/Cas9 gene editing and screened the milk of these mice for its ability to synthesize N,N‐diacetyllactosamine. [ABSTRACT FROM AUTHOR]

This paper makes an effort to establish an explicit expression of Sauter Mean Diameter (SMD) based on the stability analysis theory and images of liquid jet surfaces observed in the experiments. It is believed that waves in a certain wavelength range will form liquid tongues on the surface of the liquid jet. Under the action of aerodynamic force, these liquid tongues will finally peel off and breakup into droplets. In this paper, we extend the classical linear stability theory and then obtain the explicit expression of SMD through full-wave integration according to the mass conservation. Based on this breakup model, the results of the derived SMD expression match favorably with the experimental data. [ABSTRACT FROM AUTHOR]

Stem cell transplantation is nearly available for clinical application in the treatment of ischaemic heart disease (IHD), where it may be joined traditional methods (intervention and surgery). The angiogenic ability of seed cells is essential for this applicability. The aim of this study was to reveal the presence of CD34+ angiogenic stem cells in human decidua at the first trimester and to use their strong angiogenic capacity in the treatment of IHD. In vitro, human decidual CD34+ (dCD34+) cells from the first trimester have strong proliferation and clonality abilities. After ruling out the possibility that they were vascular endothelial cells and mesenchymal stem cells (MSCs), dCD34+ cells were found to be able to form tube structures after differentiation. Their angiogenic capacity was obviously superior to that of bone marrow mesenchymal stem cells (BMSCs). At the same time, these cells had immunogenicity similar to that of BMSCs. Following induction of myocardial infarction (MI) in adult rats, infarct size decreased and cardiac function was significantly enhanced after dCD34+ cell transplantation. The survival rate of cells increased, and more neovasculature was found following dCD34+ cell transplantation. Therefore, this study confirms the existence of CD34+ stem cells with strong angiogenic ability in human decidua from the first trimester, which can provide a new option for cell‐based therapies for ischaemic diseases, especially IHD. [ABSTRACT FROM AUTHOR]