HPV-related oropharyngeal cancer: a review on burden of the disease and opportunities for prevention and early detection

The incidence of oropharyngeal cancer (OPC) related to infection with human papillomavirus (HPV) is rising, making it now the most common HPV-related malignancy in the United States. These tumors present differently than traditional mucosal head and neck cancers, and those affected often lack classic risk factors such as tobacco and alcohol use. Currently, there are no approved approaches for prevention and early detection of disease, thus leading many patients to present with advanced cancers requiring intense surgical or nonsurgical therapies resulting in significant side effects and cost to the health-care system. In this review, we outline the evolving epidemiology of HPV-related OPC. We also summarize the available evidence corresponding to HPV-related OPC prevention, including efficacy and safety of the HPV vaccine in preventing oral HPV infections. Finally, we describe emerging techniques for identifying and screening those who may be at high risk for developing these tumors

Microstructure and interfacial reactions during active metal brazing of stainless steel to titanium

Microstructural evolution and interfacial reactions during active metal vacuum brazing of Ti (grade-2) and stainless steel (SS 304L) using a Ag-based alloy containing Cu, Ti, and Al was investigated. A Ni-depleted solid solution layer and a discontinuous layer of (Ni,Fe)2TiAl intermetallic compound formed on the SS surface and adjacent to the SS-braze alloy interface, respectively. Three parallel contiguous layers of intermetallic compounds, CuTi, AgTi, and (Ag,Cu)Ti2, formed at the Ti-braze alloy interface. The diffusion path for the reaction at this interface was established. Transmission electron microscopy revealed formation of nanocrystals of Ag-Cu alloy of size ranging between 20 and 30 nm in the unreacted braze alloy layer. The interdiffusion zone of β-Ti(Ag,Cu) solid solution, formed on the Ti side of the joint, showed eutectoid decomposition to lamellar colonies of α-Ti and internally twinned (Cu,Ag)Ti2 inter- metallic phase, with an orientation relationship between the two. Bend tests indicated that the failure in the joints occurred by formation and propagation of the crack mostly along the Ti- braze alloy interface, through the (Ag,Cu)Ti2 phase layer

Multiple-Source Single-Output Buck-Boost DC–DC Converter with Increased Reliability for Photovoltaic (PV) Applications

This paper presents an improved topology for a DC–DC converter suitable for PV applications. The proposed converter has the ability to be energized from multiple DC sources. Hence, it can be energized from two, three or a higher number of sources according to the number of modules adopted in its design. The proposed converter can supply a single load with DC power at a voltage lower or higher than the summation of all excitation DC voltages with a non-reversed voltage polarity at its output. Moreover, it provides a more reliable operation compared to other DC–DC converters due to its ability for operation with partial failures in its exciting sources. In this paper, the theoretical discussion of the proposed converter is presented considering its construction and its principle of operation. The performance of the proposed converter is theoretically evaluated using simulation based on power simulation (PSIM) software at different conditions. The performance of the converter is theoretically evaluated using PSIM considering photovoltaic (PV) sources as input sources for the proposed converter to show its validity for renewable energy applications. For more evaluation, experimental work is carried out by building a prototype and testing it at different operating conditions