Operational issues and network effects in vaccine markets

One of the most important concerns for managing public health is the prevention of infectious diseases. Although vaccines provide the most effective means for preventing infectious diseases, there are two main reasons why it is often difficult to reach a socially optimal level of vaccine coverage: (i) the emergence of operational issues (such as yield uncertainty) on the supply side, and (ii) the existence of negative network effects on the consumption side. In particular, uncertainties about production yield and vaccine imperfections often make manufacturing some vaccines a risky process and may lead the manufacturer to produce below the socially optimal level. At the same time, negative network effects provide incentives to potential consumers to free ride off the immunity of the vaccinated population. In this research, we consider how a central policy-maker can induce a socially optimal vaccine coverage through the use of incentives to both consumers and the vaccine manufacturer. We consider a monopoly market for an imperfect vaccine; we show that a fixed two-part subsidy is unable to coordinate the market, but derive a two-part menu of subsidies that leads to a socially efficient level of coverage.     

Preparation of bismuth sulfide nanoparticles as targeted biocompatible nano-radiosensitizer and carrier of methotrexate

In this study, Bi₂S₃@BSA–Bio–MTX nanoparticles (NPs) were synthesized for the first time by bovine serum albumin (BSA)-mediated biomineralization (Bi₂S₃@BSA NPs) followed by covalent bonding of biotin (Bio) and methotrexate (MTX) on the surface of the Bi₂S₃@BSA NPs via carbodiimide chemistry. The synthesized NPs were globular and exhibited uniform morphology with a hydrodynamic diameter of 107.6 ± 6.81 nm (mean ± standard deviation) and zeta potential of −20.9 ± 2.18 mV. Drug release from Bi₂S₃@BSA–Bio–MTX NPs indicated an enzyme-dependent release pattern. The in vitro biocompatibility of NPs was confirmed by investigating their cytotoxicity against the HEK-293 cell line and hemolysis assay test, whereas the in vivo biocompatibility of the NPs was evaluated and confirmed by the lethal dose 50 (LD₅₀) test. To evaluate the in vitro anticancer activity of the functionalized NPs and MTX, their cytotoxic effects was assessed against 4T1 cancer cells by 5-dimethylthiazol-z-yl)-2,5-diphenyltetrazolium bromide (MTT) assay with and without X-ray radiation. Results showed that Bi₂S₃@BSA–Bio–MTX NPs have excellent anticancer activity, especially following X-ray radiation.     

Experimental and theoretical approaches to the study of the reactivity and mechanism of the substitution of phenyl 1-(2,4-dinitronaphthyl) ether with anilines derivatives

Reactions of aniline derivatives in dimethyl sulfoxide with phenyl 1-(2,4-dinitronaphthyl) ether yield aryl 1-(2,4-dinitronaphthyl) amine, which results in substitution of the phenoxy groups at the naphthyl ipso carbon atom. Rate constants were measured spectrophotometrically, and reaction proton transfer was rate limiting. The values of the rate coefficients indicate a rate-limiting proton transfer mechanism with significant substituent effects. The calculated activation parameters were of regular variation with substituents in 4- and 3-position in the aniline nucleophile, and the reaction proceeded through a common mechanism. Hammett's reaction constant showed that the reaction rate constants depend on the electron density of the nitrogen atom of aniline derivative, whereas the coefficient value obtained from the Brönsted relation indicated that the reaction was significantly associative and quite zwitterion like. Computational studies of the substitution were carried out based on density functional theory, and theoretical to the experimental agreement was achieved.     

Sorbent extraction behavior of a nonionic surfactant,Triton X-100, onto commercial charcoal from low level radioactive waste

In nuclear power plants and nuclear laboratories, laundry wastewater is generated from decontaminating polluted instruments, worker’s clothes and taking shower after work. Laundry wastewater contains radionuclides and surfactants. The surfactants included in laundry wastewater affect the extraction of radionuclides. Therefore, surfactants should be removed before extraction of radionuclides. The objective of the present work is to assess the ability of commercial charcoal for the removal of nonionic surfactants, where, commercial charcoal is a commonly available adsorbent for treatment. Charcoal was characterized using different analytical techniques. The isotherm models and thermodynamic parameters were evaluated. Charcoal was applied to the removal of surfactant from liquid radioactive waste. The data obtained can be used for designing a plant for treatment of surfactant rich water and wastewater economically.     

A novel algorithm to study the impact of the mismatch on analog building blocks: a case study in basic 35 nm CMOS amplifiers

In this paper, the context of modeling of the impact of mismatch and statistical variations on analogue circuit building blocks is emphasized. The aim is to develop a new algorithm which predicts the statistical behavior of important parameters of an amplifier including output resistance, voltage gain and trans-conductance. The relative error of standard deviation of statistical parameters will remain less than 5% compared with the most accurate Monte-Carlo (MC) simulations using atomistic library model-cards. In comparison with other models which are based on the normal distribution of parameters, the proposed model does not need this limiting presumption. On the other hand, the proposed algorithm is more efficient compared with time consuming MC atomistic simulations.     

Analysis of multistage amplifiers with hybrid cascode feedforward compensation using a modified model for load impedance

Hybrid cascode feedforward compensation (HCFC) is an effective technique to stabilize nano-scale three-stage amplifiers driving ultra-large load capacitors. It divides the compensation capacitance and shares it between two high-speed local feedback loops embedded within the amplifier core. In this article, a systematic approach to analyze the transfer function and to evaluate the pole expressions of nano-scale HCFC amplifiers is presented. For the first time, the equivalent output impedance is successfully modeled to approximate the complicated transfer function of the HCFC amplifier without the need for lengthy pencil-and-paper calculations. An HCFC amplifier is designed and simulated in 90-nm CMOS technology, to verify the effectiveness of the new analytic approach. The simulated transfer function of the amplifier is almost identical to a calculated transfer function derived based on the new model.     

High-Performance Thin-Layer Chromatographic Method for the Estimation of Benzyl Isothiocyanate in Salvadora persica Root Extract and Dental Care Herbal Products

JPC – Journal of Planar Chromatography – Modern TLC - A novel, simple, and sensitive high-performance thin-layer chromatography (HPTLC) method has been successfully developed and...     

Performance improvement of PDMS/PES membrane by adding silicalite-1 nanoparticles: separation of xenon and krypton

The polydimethylsiloxane (PDMS) mixed matrix membrane with dispersed phase of nanozeolite silicalite-1 has been synthesized on polyethersulphone (PES) as a support, and its performance in the gas separation of xenon and krypton has been studied. For this purpose, nanozeolite silicalite-1 is synthesized by the hydrothermal clear solution method and is characterized by XRD and SEM analysis. In this research, the separation performance of MMM has also been compared with the polymeric PDMS membrane. Furthermore, the effect of feed pressure and loading percentage of nanozeolite in the polymeric matrix are evaluated. The results indicate that the addition of nanozeolite to the polymeric matrix improves its separation performance, and that the changes of the feed pressure have no major effect. The average permeability of the krypton and xenon gases through the PDMS polymeric membrane is calculated as 1.25 × 10^?9 and 1.78 × 10^?9 cm mol/(cm² s kPa), respectively, while by adding only 5 wt% of nanosilicalite-1 to the polymeric matrix of the membrane, this amount increased to 1.82 × 10^?9 and 8.07 × 10^?9 cm mol/(cm² s kPa), respectively. In addition, the presence of nanosilicalite-1 as the filler leads to an increase in the selectivity of xenon to krypton up to 4.38.