In vitro terahertz spectroscopy of gelatin-embedded human brain tumors - a pilot study

We have performed the in vitro terahertz (THz) spectroscopy of human brain tumors. In order to x tissue

Controlled focusing of silver nanoparticles beam to form the microstructures on substrates

The aerodynamic focusing in the coaxial nozzle and deposition on substrates of silver nanoparticles beams at the high subsonic speeds has been studied. The multi-spark discharge generator was used as a source of silver nanoparticles. We established that controlling the high-speed sheath flow allows to provide the minimization of the aerosol beam diameter for 4 times and printing of silver lines with width up to 60 μm using a nozzle 100 μm in outlet diameter. It was realized due to usage of high-speed beams of silver nanoparticle agglomerates, with the size of 25–110 nm, consisting of the primary particles with diameter of 5–10 nm. The agglomeration effect of aerosol nanoparticles plays a positive role providing particle deposition onto a substrate and substantially reducing diffusion broadening of an aerosol beam

MEMS Sensors Based on Very Thin LTCC

The application of thin LTCC is a very interesting and promising approach to the fabrication of ceramic MEMS gas sensors. The attempts to use this material were restricted till now by the thickness of commercial material (>50 μm). In this work, we found a possibility to fabricate thin LTCC membranes (20–30 μm) stretched on a frame made of 100 μm thick LTCC. Aerosol jet printed Pt microheater and laser cutting of the membrane gave a cantilever shaped microhotplate with hot spot of about 300 × 300 μm. Power consumption of the heater is ~150 mW at 450 °C

The Zhenya Mammoth ( Mammuthus primigenius (Blum.)): Taphonomy, geology, age, morphology and ancient DNA of a 48,000 year old frozen mummy from western Taimyr, Russia

This paper reports the results of an in-depth analysis of the frozen remains of a woolly mammoth (Mammuthus primigenius) named Zhenya, which has been dated to 48,000 cal BP. The carcass, found near the mouth of the Yenisey River in eastern Siberia, was a juvenile male whose ontogenetic age at death was 8-10 AEY. Its reconstructed live height at the shoulders (pSH 227.4 cm) was the equal of some adult female woolly mammoths and extant elephants. The large stature and a flaked off tusk tip that matches breaks on tusks of male African elephants are indirect indications that this mammoth most likely had reached sexual maturity, had been expelled from its maternal herd, and had been in at least one fight with another male. The mammoth's bones were relatively healthy, although some had minor lesions. Rudimentary upper second molars (M2/m2) were present, but no lower second molars were found in the alveoli, and the left tusk had never developed. Despite the abnormal development of the upper and lower second molars, the cheek teeth which were in wear (Dp4/dp4 and M1/m1) showed normal function without any indications of developmental delay. The completed growth of the light-colored dentin bands on the tusk strongly suggests the Fall of the year was the season of death. This season is also supported by accumulated fat in the upper parts of the torso, indicative of physiological preparation for the winter ahead. The few minor traces of carnivore scavenging, the little disturbed condition of the carcass, and the absence of bone modifications made by human actions, along with the social status of this young male animal, are interpreted here as highly probable evidence that the Zhenya Mammoth died from unrecoverable injuries inflicted during a bull-to-bull fight. The mineralogical analysis of site sediments revealed that the mammoth's burial in situ took place in the Yenisey River valley seasonally inundated by the river, which together with Fall's freezing temperatures protected the carcass from scavengers. An analysis of ancient DNA provides strong support for Zhenya's mitochondrial lineage within the deeply diverging clade III haplogroup B

Terahertz dielectric spectroscopy of human brain gliomas and intact tissues ex vivo: double-Debye and double-overdamped-oscillator models of dielectric response

Terahertz (THz) technology offers novel opportunities in the intraoperative neurodiagnosis. Recently, the significant progress was achieved in the study of brain gliomas and intact tissues, highlighting a potential for THz technology in the intraoperative delineation of tumor margins. However, a lack of physical models describing the THz dielectric permittivity of healthy and pathological brain tissues restrains the further progress in this field. In the present work, the ex vivo THz dielectric response of human brain tissues was analyzed using relaxation models of complex dielectric permittivity. Dielectric response of tissues was parametrized by a pair of the Debye relaxators and a pair of the overdamped-oscillators – namely, the double-Debye (DD) and double-overdamped-oscillator (DO) models. Both models accurately reproduce the experimental curves for the intact tissues and the WHO Grades I–IV gliomas. While the DD model is more common for THz biophotonics, the DO model is more physically rigorous, since it satisfies the sum rule. In this way, the DO model and the sum rule were, then, applied to estimate the content of water in intact tissues and gliomas ex vivo. The observed results agreed well with the earlier-reported data, justifying water as a main endogenous label of brain tumors in the THz range. The developed models can be used to describe completely the THz-wave – human brain tissues interactions in the frameworks of classical electrodynamics, being quite important for further research and developments in THz neurodiagnosis of tumors

In vitro terahertz spectroscopy of gelatin-embedded human brain tumors - a pilot study

We have performed the in vitro terahertz (THz) spectroscopy of human brain tumors. In order to x tissue