Expression of chitosanase from Aspergillus fumigatus chitosanase in Saccharomyces cerevisiae by CRISPR-Cas9 tools.

Chitooligosaccharides (COS) find numerous applications due to their exceptional properties. Enzymatic hydrolysis of chitosan by chitosanase is considered an advantageous route for COS production. Heterologous expression of chitosanase holds significant promise, yet studies using commonly employed Escherichia coli and Pichia pastoris strains encounter challenges in subsequent handling and industrial scalability. In this investigation, we opted for using the safe yeast strain Saccharomyces cerevisiae (GRAS), obviating the need for methanol induction, resulting in successful expression. Ultimately, utilizing the GTR-CRISPR editing system, shake flask enzyme activity reached 2 U/ml. The optimal chitosanase activity was achieved at 55℃ and pH 5, with favorable stability between 30 and 50 °C. Following a 2-h catalytic reaction, the product primarily consisted of chitobiose to chitotetraose, predominantly at the chitotriose position, with a slight increase in chitobiose content observed during the later stages of enzymatic hydrolysis. The results affirm the feasibility of heterologous chitosanase expression through Saccharomyces cerevisiae, underscoring its significant industrial potential.

Promoted Deposition of Three-Dimensional Li2S on Catalytic Co Phthalocyanine Nanorods for Stable High-Loading Lithium-Sulfur Batteries.

The sulfur redox in Li-S batteries involves a complex sequence of solid-liquid-solid conversions, and reaction catalysis has recently become a focused area for further advancement. The deposition of solid Li2S from liquid Li2S4 contributes to three-quarters of the total theoretical capacity and is therefore of great significance over the entire cathode reaction. This study demonstrates a cathode material composed of carbon nanofibers decorated with catalytic Co phthalocyanine nanorods (CoPc@CNF), which are highly effective in promoting the deposition of Li2S in three-dimensional (3D) fine particles rather than 2D thin films. This significantly alleviates cathode passivation during cell charge and discharge, leading to obviously improved sulfur utilization and cycling stability for high loading cathodes. DFT calculations indicate that the promoted 3D deposition of Li2S is related to the facilitated migration of deposition precursors (Li2S4 and Li-ions) to migrate on the CoPc nanorods. Lithium-sulfur (Li-S) pouch cells were prepared with high specific (954 mAh g-1), areal (4.8 mAh cm-2), and total (235 mAh) capacities achieved at 0.5 C under high sulfur content. As metal phthalocyanines possess a high structural variability, this study provides opportunities to the design of a new class of Li-S cathode materials.

Early Laparoscopic Radiofrequency Ablation for Spontaneous Rupture of Hepatocellular Carcinoma.

AIMS: To evaluate the technical and clinical outcomes of early laparoscopic radiofrequency (RF) ablation for spontaneously ruptured hepatocellular carcinoma (HCC). METHODS: From April 2005 to July 2015, ten patients with spontaneously ruptured HCC treated by laparoscopic RF ablation in our hospital were included in the study. The post treatment outcomes were recorded and analyzed. RESULTS: The mean size of the 10 HCCs was 6.6 ± 2.2 cm (4.0-10.1 cm) in the maximal dimension. Procedures of laparoscopic RF ablation were performed successfully for all patients. Complete ablation was achieved in 60.0% patients (6/10). Four patients with incompletely ablated tumors received repeated RF ablation to achieve complete ablation. During clinical follow-up, 3 (30.0%) patients developed minor complications and no patient had peritoneal recurrence. As of March 2016 (with a mean follow-up of 32.9 months), 3 patients (30.0%) were alive and 7 (70.0%) died. Of the 10 patients, the 1- and 3-year survival rates were 90.0% and 70.0%, respectively. CONCLUSION: Early laparoscopic RF ablation therapy is an effective treatment measure for spontaneously ruptured HCC in selected patients, which presents an advantage of achieving simultaneous hemostasis, tumor elimination, and rinsing of peritoneal cavity to minimize the risk of peritoneal metastasis.

Radiofrequency Ablation of the Main Lesion of Hepatocellular Carcinoma and Bile Duct Tumor Thrombus as a Radical Therapeutic Alternative: Two Case Reports.

Hepatocellular carcinoma (HCC) with bile duct tumor thrombus (BDTT) formation is a rare entity found microscopically in 1% to 9.2% of resected specimens. The ideal treatment for HCC is surgical resection. However, because of poor hepatic functional reserve in patients with HCC, most tumors are unresectable. Here, we report 2 cases of HCC with BDTT type III accompanied by hepatic dysfunction that were successfully treated with radiofrequency (RF) ablation. We used RF ablation as both a radical therapeutic method and an efficient way to control bleeding from the origin of BDTT after BDTT removal. At the time of writing, the 2 patients have been disease-free for 16 and 12 months, respectively.Our results show that RF ablation may be used as a radical therapeutic alternative for HCC with BDTT in patients with liver cirrhosis and obstructive jaundice.