An ultra-low-cost electroporator with microneedle electrodes (ePatch) for SARS-CoV-2 vaccination

Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other pathogens with pandemic potential requires safe, protective, inexpensive, and easily accessible vaccines that can be developed and manufactured rapidly at a large scale. DNA vaccines can achieve these criteria, but induction of strong immune responses has often required bulky, expensive electroporation devices. Here, we report an ultra-low-cost (<1 USD), handheld (<50 g) electroporation system utilizing a microneedle electrode array (“ePatch”) for DNA vaccination against SARS-CoV-2. The low cost and small size are achieved by combining a thumb-operated piezoelectric pulser derived from a common household stove lighter that emits microsecond, bipolar, oscillatory electric pulses and a microneedle electrode array that targets delivery of high electric field strength pulses to the skin’s epidermis. Antibody responses against SARS-CoV-2 induced by this electroporation system in mice were strong and enabled at least 10-fold dose sparing compared to conventional intramuscular or intradermal injection of the DNA vaccine. Vaccination was well tolerated with mild, transient effects on the skin. This ePatch system is easily portable, without any battery or other power source supply, offering an attractive, inexpensive approach for rapid and accessible DNA vaccination to combat COVID-19, as well as other epidemics.

Application of Broadband Microwave Near-Field Sensors for Glucose Monitoring in Biological Media

The paper presents results of numerical simulation and experimental testing of a microwave sensor for non-invasive glucose monitoring. The sensor represents a conical horn with a conical conductor inside expanding toward the horn aperture. Such a sensor has a significantly wider passband in comparison with sensors of other designs. It is essential that the sensor geometry provides formation of an extended near-field zone with high electric field strength near the sensor aperture. A clear relationship between the dielectric permittivity of the phantom biological tissue and the frequency dependence of the parameter S11 of the sensor is observed at frequencies in the range from 1.4 to 1.7 GHz. This circumstance can be used to develop a procedure for measuring the glucose level in blood that correlates with the parameter S11 of the sensor. From the viewpoint of monitoring of the glucose content in blood, the most convenient body sensor location is on the hands or feet, in particular, wrists.

Study of the Conversion of Carbon-containing and Organochlorine Impurities in the Process of Hydrogen Reduction of Silicon Tetrachloride by RF (40.68 MHz) Arc Discharge.

A contracted RF (40.68 MHz) arc discharge of atmospheric pressure, stabilized between two rod electrodes, was used to obtain trichlorosilane by the reaction of hydrogen reduction of silicon tetrachloride (SiCl₄). In model mixtures of macro-composition in the ratio H₂/SiCl₄/CCl₄=10/1/1, it was shown that C and SiC are the main solid-phase product which are deposited on the surface of electrodes in the form of dendrides. The temperature of the ends of the electrodes determined using emission thermometry is 1600 K. The thermodynamic analysis of H₂+SiCl₄+CCl₄ system confirms that the formation of C and SiC occurs in the temperature range of 1600 K. The deposition of solid-phase products occurs on the electrodes in the zone of high electric field strength.

Деградация и разрушение тонких стальных пленок при многократном воздействии сверхкоротких импульсов THz-излучения

The investigations upon destruction of thin stainless films under the action of ultrashort pulses of directional terahertz radiation are carried out. The terahertz pulse with duration within several picoseconds in fact simulates non-resonance action on matter of quasi-dc electric field with a high electric field strength (up to 20 MV/cm).

MICROWAVE INSTALLATIONS WITH NON-TRADITIONAL RESONATORS FOR COLLECTING FUR FROM RABBITS’ SKIN

The paper describes the developed ultrahigh-frequency installations with toroidal and conical resonators used for separating rabbits’ fur from hides providing high electric field strength, continuity of the technological process while observing radio-tightness and improving the quality of fluff by improving microwave technology and ultra-high-frequency installations. The technological process of collecting hair from rabbits’ skins in a microwave device with toroidal resonators is due to the weakening of the retention of the hair cover in hair follicles during the selective dielectric heating of the components of the skin and the spraying of the brine. In a biconical resonator, it is possible to obtain the highest possible high quality factor due to small longitudinal currents in the walls. The presence of gaps in the outermost regions provides the ability to move the skin through the internal cavity of the biconical resonator, where the emitters are located in the region of its maximum diameter.

3kV 4H-SiC Thyristors for Pulsed Power Applications

Due to the Silicon Carbide (SiC) material’s high electric field strength, wide bandgap, and good thermal conductivity, 4H-SiC thyristors are attractive candidates for pulsed power applications. With a thinner blocking layer almost an order of magnitude smaller than its Silicon (Si) counterpart, these devices promise very fast turn-on capabilities as full conductivity modulation occurs >10 times faster than comparable silicon thyristors, low leakage currents at high junction temperatures and at high voltage, and much lower forward voltage drop at high pulse currents. Our progress on the development of large area (4mm x 4mm) SiC thyristors is presented in this paper.