A new global accessibility algorithm for a polyhedral model with convex polygonal facets

Global accessibility information of a CAD model has been utilized widely in various manufacturing applications. This information needs fast-computing to improve the efficiency of manufacturability analysis. It needs compact representation to increase the effective utilization in its process-planning task. We propose a new geometric algorithm to explicitly find the global accessibility cones (GAC) of a polyhedral model. The proposed algorithm has three main steps. The first is concave region extraction, collecting facets that are not on the convex hull of the entire model. Second, inaccessibility of convex polygonal facets in these concave regions is analyzed in order to find their inaccessibility cones (IAC). The method is done in 2D instead of 3D. Finally, to compute GACs of those facets, the complement of the IACs union is determined for an exact solution, while the slicing-method is proposed to find a near-exact solution. In this paper, geometric examples are demonstrated and a comparison of the computational complexity with existing algorithms is provided.     

Comparative production of a monoclonal antibody specific for enrofloxacin in a stirred-tank bioreactor

A hybridoma producing monoclonal antibody (MAb) specific for enrofloxacin was cultivated in a 2-L stirred-tank bioreactor in various modes and the performances of each mode were compared. In batch mode, a maximum viable cell and MAb concentration of 9.21 × 10⁵ cells mL^?1 and 67.3 mg L^?1, respectively, were obtained. When the hybridoma was cultivated in a fed-batch culture with the addition of specific nutrients, no improvement in either the viable cell number or MAb concentration was observed. On the other hand, an increase in the production of toxic metabolites, i.e. ammonia and lactate, was observed with growth inhibition of the hybridoma cells occurring at ammonia and lactate concentrations of 2.0 mM and 2.0 g L^?1, respectively. However, the best performance of hybridoma cultivation was achieved in a perfusion culture mode using a spin filter, which was installed in the stirred-tank reactor as a cell retention device with a perfusion rate of 0.80 vvd. Under these conditions a steady viable cell concentration of 1.57 × 10⁶ cells mL^?1 was obtained within five days with an overall productivity and yield of 73.7 mg L^?1 d^?1 and 61.4 mg d^?1, respectively, which was a significant increase over that attained with the batch process.     

Enzymatic hydrolysis of rawhide using papain and neutrase

Rawhide split was hydrolysed separately by two proteolytic enzymes, papain and neutrase. The effects of enzymatic conditions of the hydrolysis reaction were investigated. During the first 10 min of the enzymatic hydrolysis, the yield of the hydrolysed protein increased sharply, then it slowly increased or became essentially constant due to the limited availability of the substrate. The optimum hydrolysis conditions of papain and neutrase for highest protein yield are at 70 °C, pH 6–7 and 40–50 °C, pH 6–7, respectively. The product from papain hydrolysis is a gelatin with low gel strength and viscosity, while that from neutrase hydrolysis is collagen hydrolysate with viscosity as low as water. This is considered to indicate that longer fragments of protein are obtained from papain hydrolysis than that from neutrase implying different mechanisms of papain and neutrase hydrolysis.     

Development of a monoclonal antibody-based enzyme-linked immunosorbent assay for detection of the furaltadone metabolite,AMOZ, in fortified shrimp samples

3-Amino-5-morpholinomethyl-2-oxazolidone (AMOZ) is a tissue bound metabolite of furaltadone, a synthetic nitrofuran antibiotic widely used in veterinary practices both to treat infectious diseases and as a growth promoter. Because AMOZ is carcinogenic and poses a potential health hazard for human consumers, its parent compounds, the nitrofurans, are banned from being used in animals destined for human food consumption in various countries. To enforce this, foods are routinely monitored for nitrofuran metabolite residues including AMOZ. Thus, reliable high throughput analytical methods to detect AMOZ have been developed but these are mostly based on chemical analysis. In contrast, sensitive and specific detection methods based on immunoassays for AMOZ using monoclonal antibodies have yet to be established. In this study, we report the generation of two monoclonal antibodies with high specificity for AMOZ and the development of a monoclonal antibody-based ELISA to detect AMOZ in shrimp samples using one of these clones (clone 2E5.1). Clone 2E5.1 yielded the highest sensitivity and specificity and cross reacted solely to furaltadone and AMOZ and not to other antibiotics. Competitive ELISA with 2E5.1 gave IC₅₀ values for AMOZ, CPAMOZ and furaltadone of 5.33, 0.023 and 1.330 ng/ml, respectively. When applied in ELISA to detect AMOZ in fortified shrimp samples, the detection capability and limit of detection were 0.3 and 0.16 μg/kg, respectively. Taken together, a sensitive and specific monoclonal antibody-based ELISA for AMOZ detection has been developed that could facilitate the economic and reliable high throughput monitoring of AMOZ in shrimps and potentially other food.