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Despite decreases in overall HIV mortality in the U.S., large racial inequities persist. Most previous analyses of HIV mortality and mortality inequities have utilized national- or state-level data. Using vital statistics mortality data and American Community Survey population estimates, we calculated HIV mortality rates and Black:White HIV mortality rate ratios (RR) for the 30 most populous U.S. cities at two time points, 2010–2014 (T1) and 2015–2019 (T2). Almost all cities (28) had HIV mortality rates higher than the national rate at both time points. At T2, HIV mortality rates ranged from 0.8 per 100,000 (San Jose, CA) to 15.2 per 100,000 (Baltimore, MD). Across cities, Black people were approximately 2–8 times more likely to die from HIV compared to White people at both time points. Over the decade, these racial disparities decreased at the national level (T1: RR = 11.0, T2: RR = 9.8), and in one city (Charlotte, NC). We identified large geographic and racial inequities in HIV mortality in U.S. urban areas. These city-specific data may motivate change in cities and can help guide city leaders and other health advocates as they implement, test, and support policies and programming to decrease HIV mortality. [ABSTRACT FROM AUTHOR]

A new class of frequency-selective surfaces (FSSs), to be used as quasi-optical filters for harmonic suppression in submillimeter-wave frequency multipliers, is proposed and experimentally verified. The FSSs consist of two-dimensional aperture arrays and are made from microstructured aluminum on electrically thick, high-resistivity silicon substrates. This leads to a very good mechanical stability, reasonably low insertion loss, and permits manufacture of the structure by using standard processes available from the semiconductor industries. This paper presents the design, fabrication, and testing of two sets of prototypes, the former with a passband at 300 GHz and a stopband at 450 GHz and the latter with a passband at 600 GHz and a stopband at 750 GHz. For both frequency ranges, FSSs with rectangular slots and with dogbone-shaped holes have been designed by using the method of moments/boundary integral-resonant mode expansion method. The effect of ohmic and dielectric losses has been determined by using the commercial code HFSS. Several prototypes have been fabricated, and measured by terahertz time-domain spectroscopy and continuous wave measurements, showing high reproducibility of the machining process, insertion loss between 1.0 and 1.6 dB, and stopband attenuation larger than 30 dB. Finally, we demonstrate that the incidence angle can be used as a degree of freedom for fine tuning the stopband, without practically changing the frequency response in the passband. Index Terms--Frequency multipliers, frequency-selective surfaces, quasi-optics, silicon, submillimeter-wave technology.

A bandpass filter for 300 GHz with a stopband at 450 GHz based on a highly efficient binary grating as a frequency-selective element was developed and optimized. The geometry of the grating was carefully designed for a maximum difference angle between reflected beams at 300 and 450 GHz and for maximum efficiency at 300 GHz. The grating efficiency was optimized using a rigorous theory of diffraction, yielding a maximum efficiency of over 99.5% neglecting conductor losses. Antennas and elliptical mirrors are used for optimum quasi-optical illumination of the grating and Gaussian beam shaping. After an optimization and a comprehensive examination of the grating in an experimental heterodyne measurement setup at 300 GHz, the filter was implemented fixed tuned into a small housing with waveguide flanges. The fixed tuned setup with corrugated feed horns results in an overall flange-to-flange insertion loss of only 2.8 dB. Index Terms--Filter design, quasi-optics, terahertz technology.

The tetrameric structure of protein kinase CK2 is formed by cross-linkages between residues 55-70 on the beta subunit with either the residues 65-80 on the alpha subunit or residues 66-81 on the alpha prime subunit. The presence of these cross-linkages was detected by fusing CK2 with carbodiimide, subjecting them to proteolytic digestion and analyzing the digestion products. These contact sites between the beta and alpha subunits were found to be responsible for maintaining the activity and stability of the CK2 enzyme.