Nonalcoholic fatty liver disease （NAFLD） is one of the most prevalent chronic liver diseases in the world， affecting about one quarter of the global population， and it is estimated that NAFLD will become the main indication for liver transplantation by 2030. NAFLD can lead to significant abnormalities in the levels of a variety of amino acids including branched-chain amino acids， thereby promoting the development and progression of NAFLD. These results suggest that in addition to glucose and lipid metabolism， amino acid metabolism also plays an important role in the progression of NAFLD. In order to systematically understand the role and mechanism of amino acid metabolism in NAFLD， this article reviews the research advances in amino acid metabolism in NAFLD. This article aims to explore the role and mechanism of amino acid metabolism in the progression of NAFLD， so as to provide ideas and a theoretical basis for clinical prevention and treatment.

Objective: To investigate the application value of real-time virtual sonography(RVS)in the diagnosis and treatment of complicated hepatolithiasis. Methods: The retrospective and descriptive study was conducted. The clinical data of 10 patients with complicated hepatolithiasis who were admitted to Hunan Provincial People′s Hospital between October 2017 and March 2018 were collected. There were 3 males and 7 females, aged from 40 to 69 years, with an average age of 57 years. Patients received abdominal color Doppler ultrasound examination, magnetic resonance cholangiopancreatography, and upper abdominal spiral computed tomography (CT) thinly scanning + enhanced examination. Data of CT examination were imported into RVS. RVS was used to locate hepatolithiasis, relationship between stones and vessels, anatomy of bile ducts and vessels in hepatic hilus. Surgical methods included RVS-guided hilar cholangiotomy, biliary stricturoplasty, bilateral hepatojejunostomy, hepatic segmentectomy (lobectomy), and hepatolithotomy. Observation indicators: (1) surgical and postoperative situations; (2) typical case analysis; (3) follow-up. Follow-up using outpatient examination was performed to detect residual stones up to June 2019. Measurement data with skewed distribution were represented as M(range). Count data were described as absolute numbers. Results: (1) Surgical and postoperative situations: 10 patients underwent RVS-guided surgeries successfully for complicated hepatolithiasis, with successful match in RVS (difference between CT images and ultrosound images <2 mm). No residual stone was identified by choledochoscope during operation. The operation time and volume of intraoperative blood loss were 285 minutes (range, 210-360 minutes) and 200 mL (range, 100-600 mL), respectively. No blood transfusion was needed during the operations. The duration of hospital stay was 20.5 days (range, 14.0-29.0 days). There was no perioperative death. One patient had postoperative biliary leakage and abdominal infection, and was cured after conservative treatment. (2) Typical case analysis: the tenth patient, female, 60 years old, was diagnosed with complicated hepatolithiasis, and was prepared to undergo hepatolithotomy+ quadrate lobectomy and hilar cholangioplasty+ bilateral hepatojejunostomy. Preoperative CT images and intraoperative color Doppler ultrasound images of the patient were fused and matched on the sagittal section of the portal vein and the cross section of the right branch of portal vein, and stones and important vessels were marked on the images. After accurate positioning, a curette was used to remove the stones. Removal of biliary stones through hepatic parenchyma and peripheral dilated bile ducts was conducted at the site where stones obviously existed. After the stones were removed, the intrahepatic bile duct and hilar bile duct merged. The left end of the bile duct split was confirmed by real-time ultrasound. After location of portal vein was determined by ultrasound, vascular plastic surgery was perfomed to avoid stenosis. (3) Follow-up: 10 patients were followed up for 6-12 months, with a median follow-up time of 8 months. One of 10 patients was suspected residual stones at the right peripheral hepatic anterior lobe by postoperative angiography at 2 months after surgery, and was not removed stones by choledochoscope. The patient had no recurrent symptoms after T-tube removal. The other 9 patients had no residual stones. Conclusion RVS applied in complicated hepatolithiasis is helpful for the precise intraoperative diagnosis, and the surgical treatment can be safe and effective.

In order to learn the enzymatic hydrolysis characteristics of steam-explosion pretreated corn straw by cellulase, the effects of substrate concentration, cellulase concentration and temperature were determined. The kinetics of the hydrolysis reaction could be described with the Michealis-Menten equation, and the hydrolysis reaction obeyed the classical first-order reaction rate in the first three hours. In the condition of 45 degrees C and pH 5.0 and the stirring rate 120 r/min, the Michealis constant (Km) and maximum rate (Vm) for 1.2 FPU/mL of cellulase were 11.71 g/L and 1.5 g/(L x h). The kinetic model, including the parameters such as substrate concentration, enzymatic concentration and temperature, was suit for the hydrolysis reaction under the temperature range from 30 degrees C-50 degrees C.
Catalysis ; Cellulase ; chemistry ; Hydrolysis ; Kinetics ; Plant Stems ; Steam ; Zea mays