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  • Author: Xiang Liu x
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A multiscale methodology for CFD simulation of catalytic distillation bale packings

Abstract

A multiscale model for simulating the hydrodynamic behavior of catalytic bale packings has been proposed. This model combines computational fluid dynamics (CFD) and macroscopic calculation. At small scale calculation, the CFD model includes 3-D volume-of-fluid (VOF) simulation within representative elementary unit (REU) under unsteady-state conditions. The REU constitutes gauze and catalyst domain, and porous media model is applied. At large scale calculation, a new mechanistic model deduced from the unit network model is employed. Based on liquid split proportion from small scale calculation, liquid distribution of the entire bale packing can be predicted. To evaluate different packing design, three common bale arrangements, i.e. one-bale, nine-bales and seven-bales, are compared. The area-weighted Christiansen uniformity coefficient is introduced to assess the distribution performance. A comparison between simulation and experimental results is made to validate the multiscale model. The present methodology is proved to be effective to analysis and design of catalytic distillation columns.

Open access
Application of the Haar Classifier in Obstacle Target Detection
Open access
The Study on the Power Transmission Line Icing Image Edge Detection based on DTW Measure Cluster Analysis
Open access
Inhibitory effects on the HMG-CoA Reductase in the chemical constituents of the Cassia mimosoides Linn

Abstract

Cassia mimosoides Linn has been used from ancient times and used for treating hepatitis for its supposedly medically beneficial properties. In this study, different constituents of the Cassia mimosoides Linn (β-Sitosterol, Oleanolic Acid, Emodin, Carotene, Resorcinol, Luteolin, and α-L-Rhamnose) were evaluated for potential anti-HMG-CoA reductase effect. The inhibitory effects of HMG-CoA reductase of Cassia mimosoides Linn extracts and Pravastatin inhibitor at different concentrations (at doses of 1, 5, 25 or 125 μg/mL, respectively) in reaction system (70 mmol/L phosphate buffer, 200mmol/L NADPH, 5 μg HMG-CoA reductase, 2 mmol/L EDTA, 2 mmol/L cysteamine, 0.06% BSA) into 37°C preheat HMG-CoA for initiating this reaction, and then determined the change of HMG-CoA reductase activity (ΔAΔt) at 340 nm, the inhibition ratio of HMG-CoA reductase activity and its dynamic change of inhibitory effect within 15 min and the descent rate of NADPH. Emodin, Luteolin, β-Sitosterol, Oleanolic Acid, α-L-Rhamnose and Carotene showed good inhibition of HMG-CoA reductase activity. Among them, only the Emodin (1 and 5 μg/mL) groups showed a significant decrease of HMG-CoA reductase activity compared to the Pravastatin (1 and 5 μg/mL) groups respectively. In addition, the HMG-CoA reductase activity in the Emodin and Luteolin (25 and 125 μg/mL) groups was clearly lower than the Pravastatin (25 and 125 μg/mL) groups respectively. And the Emodin and Luteolin (1, 5, 25 or 125 μg/mL) groups exhibited a stable effect on inhibiting the HMG-CoA reductase within 15 min. These findings further support the exploration of Cassia mimosoides Linn as a potential agent for the treatment of hepatitis in future studies.

Open access
Endoscopic Ultrasound-guided Gastroenterostomy: A Promising Alternative to Surgery

Abstract

Recently, with the advancement of techniques, endoscopic ultrasound-guided therapies have shown distinct advantages, especially in relieving benign and malignant gastric outlet obstruction (GOO), as well as in postoperative pancreaticobiliary diseases. Herein, we present five currently used approaches in endoscopic ultrasound-guided gastroenterostomy (EUS-GE) using lumenapposing biflanged metal stents (LAMS), along with several examples of LAMS-based EUS treatment of pancreaticobiliary diseases. Compared with traditional treatment methods, EUS-guided procedures have – to some degree – shown higher success rates, both technical and clinical. Moreover, EUS-guided therapies reduce the risk of multiple surgical adverse events, including delayed gastric emptying, prolonged hospital stay, increased costs, and delay in cancer treatment. Particularly in terms of postoperative pancreaticobiliary diseases, EUS-guided therapy has assumed an essential role as a treatment option in cases where traditional methods are difficult to perform. Nevertheless, EUS-guided gastrointestinal procedures are still relatively new, with some clinical failures, and additional prospective clinical trials are warranted.

Open access
Establishment of renal failure models by laparoscopy in bama pigs which underwent partial nephrectomy and radical contralateral nephrectomy

Abstract

Introduction

The miniature pig possesses unmatched advantages as an animal model because of its high homology with humans. Our experiment aimed to build a chronic renal failure (CRF) model in pigs via laparoscopy.

Material and Methods

Laparoscopic surgery was performed twice to build a CRF model. The first surgery was a left partial nephrectomy and the second was a right radical nephrectomy. Pigs were grouped by the total renal tissue to be resected: ⅔, ¾ or ⅚. Physiological parameters (rectal temperature and heart rate), haematological parameters (WBC and RBC) and renal function (serum creatinine – CR and blood urea nitrogen – BUN) were measured preoperatively and every week postoperatively.

Results

After renal resection the pigs manifested chronic renal failure. Heart rate and body temperature declined to varying degrees over 12 postoperative weeks. No significant difference was observed between the different groups. The result of renal function tests found that postoperative serum CR and BUN in all groups were continuously elevated, and the level of serum CR at two weeks post procedure differed very significantly from its preoperative value (P < 0.05). BUN was significantly elevated at one week (P < 0.05). The renal function decreased significantly faster in the ⅚ group than in the other two groups. The trend of renal function change was similar among groups, but progress was slower in the ⅔ and ¾ groups.

Conclusion

⅚ kidney resection was the optimal miniature pig model of CRF.

Open access
Synergic Relationship and Synergic Degree between an Information System and Corporate Strategy

Abstract

With the development of information technology, the Information System (IS) has not the characters of rareness and inimitability, so an IS cannot form core competence alone. Forming synergic relationship and keeping higher synergic degree between IS and corporate strategy will help the enterprises acquire competence advantage and realize IS value. This paper analyzes the conditions of forming synergic relationship between an IS and strategy, and points out that the key factors for a synergic degree are the strategy rationality and the matching degree between the IS and strategy. Based on the analysis result and BCG growth share matrix, this paper constructed a synergy degree measure model to evaluate the synergic relationship between the IS and corporate strategy. Finally, a case study is used to verify the feasibility of the model.

Open access
Analysis on the Features of Acupuncture Recipes for Dysmenorrhea

Abstract

Objective: To analysis and extract the features of acupuncture recipes for dysmenorrhea.

Methods: By searching the major Chinese and English databases, we included the clinical literature with defined point-based recipes and analyzed the feature of those.

Results: (1) the most frequently selected points for dysmenorrhea in order were: San Yin Jiao(SP6), Guan Yuan (RN4), Zhong Ji (CV3), Qi Hai (CV6), Ci Liao (BL32), Di Ji (SP8), Shen Shu (BL23). (2) the major characteristics of point selection was combination of local points and distant points which located on Ren meridian and spleen meridian. (3) the major treatment methods were normal acupuncture, then acupuncture combined with moxibustion or auricular therapy, for the latter, were especially stressed and confirmed by many studies.

Conclusion: The acupuncture recipes for dysmenorrhea were usually made by consideration of combining local and distant points, utilizing multiple methods especially auricular therapy.

Open access
Development of a new RT-PCR with multiple primers for detecting Southern African Territories foot-and-mouth disease viruses

Abstract

Introduction: The extremely high genetic variation and the continuously emerging variants of foot-and-mouth disease virus (FMDV) of Southern African Territory (SAT) serotypes including SAT1, SAT2, and SAT3 make it necessary to develop a new RT-PCR for general use for monitoring viruses based on the updated genome information.

Material and Methods: A FMDV SAT-D8 one-step RT-PCR was established based on the 1D2A2B genes of the SAT serotype viruses with a multiplex primer set. FMDV A, O, C, and Asia 1 serotypes, other vesicular disease viruses, inactivated SAT viruses, and 125 bovine, ovine, caprine and porcine tissue samples collected from the Chinese mainland were included for evaluating the assay.

Results: The new RT-PCR was proven to be specific without cross-reactions with Eurasian FMDV, swine vesicular disease virus (SVDV), Seneca valley virus (SVV), or other common viral pathogens of cattle, sheep, goat, and pig. An around 257 bp-sized amplicon clearly appeared when the inactivated SAT viruses were detected. However, all 125 samples collected from FMDV-susceptible animals from the Chinese mainland which has not known SAT epidemics showed negative results.

Conclusions: A FMDV SAT-D8 one-step RT-PCR is a promising method for primary screening for FMDV SAT serotypes.

Open access