Background: This study was performed to investigate the imaging features of mDIXON-Quant sequence (Philips Healthcare) and proton magnetic resonance spectroscopy (1H-MRS) of thigh muscles in patients with stroke-related sarcopenia (SRS). Methods: This prospective case-control study was conducted in 40 patients with SRS, 40 patients without sarcopenia who had a stroke, and 40 healthy volunteers using mDIXON-Quant and 1H-MRS scanning. Skeletal muscle cross-sectional area (CSA) and fat fraction (FF) were analyzed. Results: The skeletal muscle FF value was significantly higher (p<0.05) in patients with SRS and on the affected side. The extracellular fat content of the rectus femoris muscle in normal controls was 4× to 10× the intracellular fat content. A significant increase (p<0.05) in intra- and extracellular fat content was detected in the SRS group. The degree of fat content increase in the SRS group was significantly lower (p<0.05) for extracellular fat than intracellular fat, with a ratio of extracellular to intracellular fat content of <4. The intracellular fat content was significantly higher (p<0.05) in the SRS group. A moderate-to-strong positive correlation existed between intracellular fat content (area 1) and muscle fat percentage. The degree of decrease in CSA in the posterior muscle group was significantly greater (p<0.05). Conclusion Thigh muscle CSA significantly decreased in SRS, while FF increased. The intra- and extracellular fat content of the skeletal muscle was significantly increased, especially the intracellular fat content. SRS was confirmed when the ratio of extracellular fat content to intracellular fat content was <4.

Geobacillus thermoglucosidasius is a kind of Gram-positive facultative anaerobic bacteria. The fast growth rate under high temperature and less susceptibility to microbial contamination enable G. thermoglucosidasius to be a desirable producer of biofuels and high-value-added chemicals for the next-generation industrial biotechnology. However, compared with the classical model strain Escherichia coli, the applications of G. thermoglucosidasius are hampered by its low transformation efficiency. This study aimed at obtaining competent cells with high transformation efficiency through inactivating restriction enzymes, adding cell membrane inhibitors and cell wall weakening agents. The results showed that the electro-transformation efficiency achieved 1.2×10⁴ CFU/(μg DNA) by knocking out four genes encoding restriction enzymes. Adding a certain amount of tween 80, dl-threonine and glycine further increased the competent efficiency about 22.5, 44, and 334 times, respectively. The electro-transformation efficiency was enhanced to 4.6×10⁶ CFU/(μg DNA) under the optimized conditions, laying a foundation for genetic manipulation and metabolic engineering of G. thermoglucosidasius.
Electroporation ; Electroporation Therapies ; Bacillaceae ; Cell Membrane ; Escherichia coli/genetics*