Targeting Human Dendritic Cells with Lewis X Modified Liposomes

In this short report, we demonstrate that liposomes bearing the Lewis X trisaccharide on the surface (“Awesosomes”) efficiently target human dendritic cells. We chose a glycolipid with Lewis X trisaccharide headgroup to facilitate the targeted liposome uptake via the DC-SIGN internalization pathway. While no uptake of Awesosomes was detected with wild-type human HEK293 cells, HEK293 cells transfected with human DC-SIGN internalized Awesosomes extensively. In samples of human blood-derived leukocytes, the extent of uptake of Awesosomes correlated with the expression of DC-SIGN, which is a dendritic cells marker. There was a marked difference in the uptake of Awesosomes and plain liposomes by DC-SIGN expressing dendritic cells. There was no difference in uptake of Awesosomes and plain liposomes by wt HEK293 cells or macrophages. These results indicate that Lewis X trisaccharide can “sweet-talk” dendritic cells into internalizing a delivery vehicle, and that Awesosomes are promising as “magic bullets” for specific delivery of drugs, antigens, or immunostimulatory molecules to human dendritic cells without influencing other cell types

Consumer uncertainty and price discrimination through online coupons: an empirical study of restaurants in Shanghai

We use data from restaurants in Shanghai, China to conduct a new empirical analysis of prices and coupons. Our results show a positive relationship between prices and online coupons. Moreover, the price premium from couponing is higher for restaurants about which consumer values appear to be more uncertain. When consumer uncertainty is high, restaurants that offer coupons have an average price that is about 60 percent higher than similar restaurants that do not issue coupons. When uncertainty is low, restaurants that offer coupons have an average price that is about ten percent higher. These findings are consistent with online couponing in the restaurant industry being used for price discrimination and as a promotional device in the presence of higher uncertainty in consumer valuations.consumer uncertainty; coupons; price discrimination; price promotion

Interpersonal bundling

This paper studies a model of interpersonal bundling, in which a monopolist offers a good for sale under a regular price and a group purchase discount if the number of consumers in a group—the bundle size—belongs to some menu of intervals. We find that this is often a profitable selling strategy in response to demand uncertainty, and it can achieve the highest profit among all possible selling mechanisms. We explain how the profitability of interpersonal bundling with a minimum or maximum group size may depend on the nature of uncertainty and on parameters of the market environment, and we discuss strategic issues related to the optimal design and implementation of these bundling schemes. Our analysis sheds light on popular marketing practices such as group purchase discounts, and it offers insights on potential new marketing innovation

A Practical Model for a Dense- Bed Countercurrent FCC Regenerator

In this study, a new practical countercurrent regenerator model for in-situ FCC operation optimization was proposed. A three-zone-and-two-phase gas model and a new two-CSTR-with-interchange model were used to give better descriptions on the gas and solids flow patterns, addressing the region-dependent mass transfer rates and the freeboard effect on catalyst regeneration. The model coupled mass and heat balances, hydrodynamics and reaction kinetics. The modeled results are in reasonable agreement with the commercial data from an industrial FCC regenerator under both partial and full CO combustion modes

Dynamic behaviour of optimal portfolio with stochastic volatility

In the existing literature, little is known about the dynamic behaviour of the optimal portfolio in terms of market inputs and arbitrary stochastic factor dynamics in an incomplete market with a stochastic volatility. In this paper, to study optimal portfolio behaviour, we compute and analyze the mean and the variance of the optimal portfolio and of their adjustment speed in terms of market inputs in an incomplete market. The incompleteness arises from the additional source of uncertainty of the volatility in Heston’s stochastic volatility model. Conducting sensitivity analysis for the mean and the variance of the optimal portfolio process as well as its adjustment speed to the market parameters, we find several interesting behavioural patterns of investors towards asset price and its volatility shocks. Our results are robust and convergent by the agreement from two simulation methods for different time step increments and the number of Monte Carlo simulation paths

Experience Goods and Consumer Search

We introduce a search model where products differ in variety and unobserved quality (`experience goods'), and firms can establish quality reputation. We show that the inability of consumers to observe quality before purchase significantly changes how search frictions affect market performance. In equilibrium, higher search costs hinder consumers' search for better-matched variety and increase price, but can boost firms' investment in product quality. Under plausible conditions, both consumer and total welfare initially increase in search cost, whereas both would monotonically decrease if quality were observable. We apply the analysis to online markets, where low search costs coexist with low-quality products

Experience Goods and Consumer Search

We introduce a search model where products differ in variety and unobserved quality (`experience goods'), and firms can establish quality reputation. We show that the inability of consumers to observe quality before purchase significantly changes how search frictions affect market performance. In equilibrium, higher search costs hinder consumers' search for better-matched variety and increase price, but can boost firms' investment in product quality. Under plausible conditions, both consumer and total welfare initially increase in search cost, whereas both would monotonically decrease if quality were observable. We apply the analysis to online markets, where low search costs coexist with low-quality products

Experimental study on a new FCC spent catalyst distributor

In the regenerator of an industrial fluid catalytic cracker (FCC), uniform distribution of its solids reactant, i.e. spent catalyst, plays a crucial role in obtaining better regenerator performance. In traditional FCC unit designs, there was usually no spent catalyst distributor or some intuitive designs with simple structures, i.e. boat or pipe distributors in most China’s FCC units (1). In this study, we built a large cold experimental installation to evaluate the performances of various spent catalyst distributors. Distribution uniformity and solids flow resistance were the main target indices for distributor performance evaluation. The experimental results indicate that the boat distributor has the poorest performance, as solids flows preferentially through the few front openings. At high gas flowrates, the pipe distributor can obtain a relative uniform solids distribution, but its flow resistance is also higher. Good flowability of solids that is difficult to maintain throughout the distributor was found to be the root cause of their bad distribution performance. Referring to the idea of an air-slide solids transportation system (2-4), a new slot spent catalyst distributor was proposed. Its performance was systematically evaluated in a large cold model unit. It was found that the new slot distributor has a critical superficial gas velocity, beyond which good solids distribution uniformity and high solids transportation capacity can be both maintained. Compared with traditional boat and pipe spent catalyst distributors, the new slot distributor is much more advantageous comprehensively, e.g. in solids distribution uniformity, solids transportation capacity and operating flexibility. Please click Additional Files below to see the full abstract

Investigation of particle-wall interaction in a pseudo-2D fluidized bed using CFD-DEM simulations

We report on discrete element method simulations of a pseudo-two-dimensional (pseudo-2D) fluidized bed to investigate particle-wall interactions. Detailed information on macroscopic flow field variables, including solids pressure, granular temperature, and normal and tangential wall stresses are analyzed. The normal wall stress differs from the solids pressure because of the strong anisotropic flow behavior in the pseudo-2D system. A simple linear relationship exists between normal wall stress and solids pressure. In addition, an effective friction coefficient can be derived to characterize particle-wall flow interaction after evaluating the normal and tangential wall stresses. The effects of inter-particle and particle-wall friction coefficients are evaluated. Strong anisotropic flow behavior in the pseudo-2D system needs to be considered to validate the two-fluid model where the boundary condition is usually developed based on an isotropic assumption. The conclusion has been confirmed by simulation with different particle stiffnesses. Assumptions in the newly developed model for 2D simulation are further examined against the discrete element method simulation.This technical report was produced in support of the National Energy Technology Laboratory's ongoing research in advanced numerical simulation of multiphase flow under RES contract DE-FE0004000