Non-invasive Imaging of Sense of Smell by Tracking the Voltage-Gated Sodium Channel NaV1.7

Background: Anosmia/hyposmia affects 13.3 million people in the U.S. alone according to the recent U.S. National Health and Nutrition Examination Survey (NHANES). Hundreds of thousands more people with persistent olfactory dysfunction will be added to this number due to the COVID-19 pandemic. Patients with loss-of-function mutations in SCN9A, the gene encoding NaV1.7, experience anosmia in addition to congenital insensitivity to pain. Tsp1a is a recently discovered peptide that inhibits NaV1.7 with high potency and selectivity. In this study, we examined whether a fluorescently tagged version of Tsp1a could be used to visualize normal and damaged mouse olfactory nerves. Methods: Athymic nude mice were intravenously injected with Tsp1a-IR800. As a control, mice were injected with PBS only, and as a blocking control were injected with combination of Tsp1a and Tsp1a-IR800. All mice were imaged in-vivo and epifluorescence images were acquired using an IVIS Spectrum animal imaging system. Semiquantitative analysis of the Tsp1a-IR800 signal was conducted by measuring the average radiant efficiency in the region of the olfactory epithelium/bulb (ROEB). Methimazole was used to chemically ablate the olfactory epithelium. We performed a food buried test to correlate the level of anosmia with the level of radiance efficiency. Results: The area of olfactory epithelium/bulb was clearly visible in epifluorescence in-vivo images of mice receiving the imaging agent. The radiant efficiency was significantly less in both mice injected with PBS and in mice injected with the blocking formulation. The mice after olfactory ablation had a significantly reduced radiant efficiency compared with normal mice. Moreover, there was a statistically significant and inverse correlation between the time required for the mouse to find buried food and the radiant efficiency. We also performed immunohistochemistry using NaV1.7 antibody. Mice after olfactory ablation as well as COVID-19-infected mice had significantly lower expression of NaV1.7 on the level of olfactory epithelium/bulb. Conclusion: We show that the fluorescent imaging of mouse olfactory epithelium/bulb is possible, suggesting that labeled Tsp1a tracers may serve as the first objective diagnostic tool of smell disorders, including those caused by COVID-19.

Estimation of the Ultraviolet-C Doses from Mercury Lamps and Light-Emitting Diodes Required to Disinfect Surfaces

Disinfection of surfaces by ultraviolet-C (UV-C) radiation is gaining importance in diverse applications. However, there is generally no accepted computational procedure to determine the minimum irradiation times and UV-C doses required for reliable and secure disinfection of surfaces. UV-C dose distributions must be comparable for devices presently on the market and future ones, as well as for the diverse surfaces of objects to be disinfected. A mathematical model is presented to estimate irradiance distributions. To this end, the relevant parameters are defined. These parameters are the optical properties of the UV-C light sources, such as wavelength and emitted optical power, as well as electrical features, like radiant efficiency and consumed power. Furthermore, the characteristics and geometry of the irradiated surfaces as well as the positions of the irradiated surfaces in relation to the UV-C light sources are considered. Because mercury (Hg) lamps are competitive with UV-C light-emitting diodes, a comparative analysis between these two light sources based on the simulation results is also discussed.

Ovarian Accumulation of Nanoemulsions: Impact of Mice Age and Particle Size

Nanotechnology in the field of drug delivery comes with great benefits due to the unique physicochemical properties of newly developed nanocarriers. However, they may come as well with severe toxicological side effects because of unwanted accumulation in organs outside of their targeted site of actions. Several studies showed an unintended accumulation of various nanocarriers in female sex organs, especially in the ovaries. Some led to inflammation, fibrosis, or decreasing follicle numbers. However, none of these studies investigated ovarian accumulation in context to both reproductive aging and particle size. Besides the influences of particle size, the biodistribution profile may be altered as well by reproductive aging because of reduced capacities of the reticuloendothelial system (RES), changes in sex steroid hormone levels as well as altering ovarian stromal blood flow. This systematic investigation of the biodistribution of intravenously (i.v) injected nanoemulsions revealed significant dependencies on the two parameters particle size and age starting from juvenile prepubescent to senescent mice. Using fluorescent in vivo and ex vivo imaging, prepubescent mice showed nearly no accumulation of nanoemulsion in their uteri and ovaries, but high accumulations in the organs of the RES liver and spleen independently of the particle size. In fertile adult mice, the accumulation increased significantly in the ovaries with an increased particle size of the nanoemulsions by nearly doubling the portion of the average radiant efficiency (PARE) to ~10% of the total measured signal of all excised organs. With reproductive aging and hence loss of fertility in senescent mice, the accumulation decreased again to moderate levels, again independently of the particle size. In conclusion, the ovarian accumulation of these nanocarriers depended on both the age plus the particle size during maturity.

Electrodeless UV Lamp on the Basis of Low-Pressure Mercury Discharge in a Closed Non-Ferrite Tube

Experimental study of characteristics of a nonferrite electrode-less UV lamp with a length of 500 mm and width of 130 mm in the form of a closed quartz discharge tube with an inner diameter of 25 mm was conducted. The induction discharge was excited at a frequency of 1.7 MHz within the discharge lamp power Ppl ranging between 52 and 112 W in a mixture of mercury (~10-2 mm Hg) and argon (1.0 mm Hg) vapours by means of a 3-coil inductance located along the inner perimeter of the closed tube. With Ppl increasing: a) loss power in the inductance wire first decreased from 37 down to 22 W (Ppl = 84 W) and then increased up to 44 W; 2) the UV radiant flux of the lamp in a mercury light-band of 54 nm increased from 28 to 72 W; 3) radiant efficiency of the lamp at the light-band of 254 nm first increased from 31 to 48.5 % (Ppl = 84 W) and then slightly decreased down to 46 %; 4) radiant efficiency of the discharge plasma at the wavelength of 254 nm increased from 53 % to 65 %.

Discussion on the Structure of Low-Temperature Radiant Heater of Gate Station

As the city develops radiady, the natural gas is widely used nealy in every filed of people’s lives. During the pressure regulation, the phenomenon of ice jam, which can affect the normal utilization, happens. Heater can be regarded as one of the most important measures that prevents pipe from freezing occurring due to temperature drop caused by pressure regulation. Low-temperature radiant heater with tight structure is specifically designed for gad gate station. The heat transfer process of the gate station is analyzed. In the meantime, the mathematical model of radiant heater, which could be fitted for the gate station, is erected. At the same time, the influence of heat exchange size, radiant panel size and radiant efficiency, brought by tube are discussed. The result shows that the tube type of radiant heater has a greatest performance. Considering the tubes with compact structure, taking tube type of radiant heater as the heater used in gate station is the optimal decision. The analysis combined in this paper is the foundation to choose the heater of gate station.