Infection of human cytomegalovirus in cultured human gingival tissue.

BackgroundHuman cytomegalovirus (HCMV) infection in the oral cavity plays an important role in its horizontal transmission and in causing viral-associated oral diseases such as gingivitis. However, little is currently known about HCMV pathogenesis in oral mucosa, partially because HCMV infection is primarily limited to human cells and few cultured tissue or animal models are available for studying HCMV infection.ResultsIn this report, we studied the infection of HCMV in a cultured gingival tissue model (EpiGingival, MatTek Co.) and investigated whether the cultured tissue can be used to study HCMV infection in the oral mucosa. HCMV replicated in tissues that were infected through the apical surface, achieving a titer of at least 300-fold at 10 days postinfection. Moreover, the virus spread from the apical surface to the basal region and reduced the thickness of the stratum coreum at the apical region. Viral proteins IE1, UL44, and UL99 were expressed in infected tissues, a characteristic of HCMV lytic replication in vivo. Studies of a collection of eight viral mutants provide the first direct evidence that a mutant with a deletion of open reading frame US18 is deficient in growth in the tissues, suggesting that HCMV encodes specific determinants for its infection in oral mucosa. Treatment by ganciclovir abolished viral growth in the infected tissues.ConclusionThese results suggest that the cultured gingival mucosa can be used as a tissue model for studying HCMV infection and for screening antivirals to block viral replication and transmission in the oral cavity

Effect of losses in an active device and harmonic network on the efficiency of Class F and inverse Class F power amplifiers

High frequency class F and inverse class F power amplifiers obtain high efficiency of dc to ac power conversion, by reducing the overlap of voltage and current waveforms at the output of the active device, to ensure that the power dissipated in the resistance Ron of the active device is minimised. In this paper the active device is modelled as a switch in series with resistance Ron 0 to 5Ω. For ideal switch voltage / current waveforms and equal dc input power for both amplifiers the efficiency of power conversion is compared. To confirm the predicted results ideal lossless load harmonic networks using lumped elements were designed to meet all frequency conditions of the two amplifiers. These networks were done used in Advanced Design System (ADS) software for Ron=0, 2 and 4 Ω. The predicted efficiency for 2Ω and 4 Ω were 80% and 60% and the obtained simulation efficiency were 83.2% and 65.5% for class F amplifier. For the inverse class F amplifier the predicted efficiency was 87.3% and 74.5% and for the simulation results it was 87.26% and 74.4%. Above predicted and simulated results show that the resistance Ron has less effect on the efficiency of inverse class F than for class F amplifier. As lumped elements can not be used at high frequencies they were replaced initially with lossless transmission lines and then by microstrip lines to also investigate also how copper and dielectric losses affect the efficiency of power conversion

The Risks of Clouded Property Title for Cannabis Business Owners, Investors, and Creditors

This Article provides a brief primer on the surprising range of assets that the Controlled Substances Act forfeiture provisions govern for the state-legal cannabis businesses. It outlines these provisions for tangible as well as intangible property, with an emphasis on risks to state-legal cannabis businesses’ intellectual property and issued securities. We argue that these forfeiture risks create clouded title for all subject tangible and intangible property—not only for the state-legal businesses and their proprietors, but also for those businesses’ outside investors, creditors, and suppliers/contractors

Pricing of Virtual Goods and Designing Game Challenge Level for Free-to-Play Mobile Games in the Presence of Copycat Competitors

In-game purchases, virtual currency, content design for heterogeneous consumers and strong competition are key challenges for mobile game providers. This study addresses determination of optimal game design strategies for game providers in the presence of heterogeneous players and copycat competitors. Moreover, this paper incorporates pricing of virtual goods/currency into the Free-to-Play (F2P) mobile game design via a duopoly model and characterizes the optimal strategies for game providers in terms of pricing of virtual goods/currency and the game challenge level