Simultaneous eigenstates of the number-difference operator and a bilinear interaction Hamiltonian derived by solving a complex differential equation

As a continuum work of Bhaumik et al who derived the common eigenvector of the number-difference operator Q and pair-annihilation operator ab (J. Phys. A9 (1976) 1507) we search for the simultaneous eigenvector of Q and (ab-a^{+}b^{+}) by setting up a complex differential equation in the bipartite entangled state representation. The differential equation is then solved in terms of the two-variable Hermite polynomials and the formal hypergeometric functions. The work is also an addendum to Mod. Phys. Lett. A 9 (1994) 1291 by Fan and Klauder, in which the common eigenkets of Q and pair creators are discussed

Mirror of Atiyah flop in symplectic geometry and stability conditions

We study the mirror operation of the Atiyah flop in symplectic geometry. We formulate the operation for a symplectic manifold with a Lagrangian fibration. Furthermore we construct geometric stability conditions on the derived Fukaya category of the deformed conifold and study the action of the mirror Atiyah flop on these stability conditions.Comment: v2: 45 pages, 18 figures; revised expositio

Investigation of Parameters That Affect the Acquired Near Infrared Diffuse Reflected Signals in Non-Destructive Soluble Solids Content Prediction

Near infrared spectroscopy is a susceptible technique which can be affected by various factors including the surface of samples. According to the Lambertian reflection, the uneven and matte surface of fruits will provide Lambertian light or diffuse reflectance where the light enters the sample tissues and that uniformly reflects out in all orientations. Bunch of researches were carried out using near infrared diffuse reflection mode in non-destructive soluble solids content (SSC) prediction whereas fewer of them studying about the geometrical effects of uneven surface of samples. Thus, this study aims to investigate the parameters that affect the near infrared diffuse reflection signals in non-destructive SSC prediction using intact pineapples. The relationship among the reflectance intensity, measurement positions, and the SSC value was studied. Next, three independent artificial neural networks were separately trained to investigate the geometrical effects on three different measurement positions. Results show that the concave surface of top and bottom parts of pineapples would affect the reflectance of light and consequently deteriorate the predictive model performance. The predictive model of middle part of pineapples achieved the best performance, i.e. root mean square error of prediction (RMSEP) and correlation coefficient of prediction (Rp) of 1.2104 °Brix and 0.7301 respectively

Therapeutic protein expression platform of microbial system

A number of expression systems have been developed for the production of pharmaceutical products. Pichia pastoris and Escherichia coli expression system operate in our lab and express antibody fragment (scFv), cytokine, protein base adjuvant and vaccine and process enzyme. The expression platform are consisted of three part, first is strain generation , the second is fermentation process development in 250 ml fermentor and the last is process scale-up to 5 litter fermentor. Please click Additional Files below to see the full abstract

A Comparison between the Post- and Pre-dispersive Near Infrared Spectroscopy in Non-Destructive Brix Prediction Using Artificial Neural Network

Even though near infrared (NIR) spectroscopy have been implemented in determining the Brix of pineapples, no traceable study compares the effects of different acquisition designs. Thus, this study aims to evaluate the prediction performance of both pre- and post-dispersive NIR sensing devices in non-destructive Brix prediction using artificial neural network (ANN). The pre-dispersive device has five narrowband light emitting diodes (LEDs) with different wavelengths and a photodiode detector, whereas the post-dispersive device has a bifurcated fiber optic, a broadband LED, and a spectral sensor. First, the NIR diffuse reflectance was non-destructively collected using both NIR devices. Then, the collected diffuse reflectance was calibrated with the white and dark references, and then pre-processed using normalization and standard normal variate methods. After that, ANNs were built for both devices using the pre-processed data. Results show both devices are suitable for sample screening application with range error ratio (RER) of more than seven. Nevertheless, the ANN that trained using the post-dispersive device outperformed that trained using the pre-dispersive device with an 8.1% improvement of correlation coefficient of prediction (i.e. from 0.6853 to 0.7408), and a 5.7% improvement of root mean square error of prediction (i.e. from 1.3918 to 1.313°Brix)

Gram Level scFv expression platform of Pichia pastoris

The methylotrophic yeast Pichia pastoris secretion expression system has been developed for the antibody fragments (scFv) production platform. The platform includes three technology platforms, the first one is strain generation, the second is fermentation process development in 250 ml fermentor and the last is process scale up to 5 L. A recombinant scFv went through clone generation, include signal peptide tool box, normally yield 2.5 mg/L titer in deep well. Through the fermentation process development of induction medium composition and feeding strategy by Eppendorf Dasgip parallel 250 ml mini fermentor. During induction step, feeding 100% methanol as induction medium can only produce less than 50 mg/L scFv while feeding methanol-sorbitol mixture can significant increase the production yield to 306 mg/L in five days, about 6-folds increase in productivity. With the supply of additional nitrogen source during glycerol feeding step or at induction step, higher scFv production with 510 mg/L can be achieved. Thus, following the medium composition optimization, the production titer was improved 10 folds in 250 ml mini-fermentor stage. Moreover, when we switched the induction medium feeding strategy from DO-stat to the stepwise feeding, the titer increased form 510 mg/L to ~1000 mg/L and yielded another 2- folds improvement. During medium composition and feeding strategy optimization at 250 ml mini fermentor scale, the production titer could increase 20 folds. Overall, the production titer increased 400 folds from cell line generation to 250 ml fermentation parameter optimization. Furthermore, the process parameter can be scale-up to 5 L fernentor achieving \u3e 1 g/L. Recent progress to include BIP in the expression vector gave at least 2 fold improvement in scFv titer in shake flask, the new clone will be optimized in our established 250 ml and 5 L fermentation platform. Please click Additional Files below to see the full abstract

Gram level scFv expression platform of Phichi pastoris

The methylotrophic yeast Pichia pastoris secretion expression system has been developed for the antibody fragments (scFv) production platform. The platform includes three technology platforms, the first one is strain generation, the second is fermentation process development in 250 ml fermentor and the last is process scale up to 5 L. A recombinant scFv went through clone generation, include signal peptide tool box, normally yield 2.5 mg/L titer in deep well. Through the fermentation process development of induction medium composition and feeding strategy by Eppendorf Dasgip parallel 250 ml mini fermentor. During induction step, feeding 100% methanol as induction medium can only produce less than 50 mg/L scFv while feeding methanol-sorbitol mixture can significant increase the production yield to 306 mg/L in five days, about 6-folds increase in productivity. With the supply of additional nitrogen source during glycerol feeding step or at induction step, higher scFv production with 510 mg/L can be achieved. Thus, following the medium composition optimization, the production titer was improved 10 folds in 250 ml mini-fermentor stage. Moreover, when we switched the induction medium feeding strategy from DO-stat to the stepwise feeding, the titer increased form 510 mg/L to ~1000 mg/L and yielded another 2- folds improvement. During medium composition and feeding strategy optimization at 250 ml mini fermentor scale, the production titer could increase 20 folds. Overall, the production titer increased 400 folds from cell line generation to 250 ml fermentation parameter optimization. Furthermore, the process parameter can be scale-up to 5 L fernentor achieving \u3e 1 g/L. Recent progress to include BIP in the expression vector gave at least 2 fold improvement in scFv titer in shake flask, the new clone will be optimized in our established 250 ml and 5 L fermentation platform Please click Additional Files below to see the full abstract