Being the largest and most visible organ of the body and heavily influenced by environmental factors, skin is ideal to study the long-term effects of aging. Throughout our lifetime, we accumulate ...damage generated by UV radiation. UV causes inflammation, immune changes, physical changes, impaired wound healing and DNA damage that promotes cellular senescence and carcinogenesis. Melanoma is the deadliest form of skin cancer and among the malignancies of highest increasing incidence over the last several decades. Melanoma incidence is directly related to age, with highest rates in individuals over the age of 55 years, making it a clear age-related disease. In this review, we will focus on UV-induced carcinogenesis and photo aging along with natural protective mechanisms that reduce amount of "realized" solar radiation dose and UV-induced injury. We will focus on the theoretical use of forskolin, a plant-derived pharmacologically active compound to protect the skin against UV injury and prevent aging symptoms by up-regulating melanin production. We will discuss its use as a topically-applied root-derived formulation of the Plectranthus barbatus (Coleus forskolii) plant that grows naturally in Asia and that has long been used in various Aryuvedic teas and therapeutic preparations.
Resveratrol is a naturally occurring polyphenol that provides a number of anti-aging health benefits including improved metabolism, cardioprotection, and cancer prevention. Much of the work on ...resveratrol and cancer comes from in vitro studies looking at resveratrol actions on cancer cells and pathways. There are, however, comparatively fewer studies that have investigated resveratrol treatment and cancer outcomes in vivo, perhaps limited by its poor bioavailability when taken orally. Although research in cell culture has shown promising and positive effects of resveratrol, evidence from rodents and humans is inconsistent. This review highlights the in vivo effects of resveratrol treatment on breast, colorectal, liver, pancreatic, and prostate cancers. Resveratrol supplementation in animal models of cancer has shown positive, neutral as well as negative outcomes depending on resveratrol route of administration, dose, tumor model, species, and other factors. Within a specific cancer type, there is variability between studies with respect to strain, age, and sex of animal used, timing and method of resveratrol supplementation, and dose of resveratrol used to study cancer endpoints. Together, the data suggest that many factors need to be considered before resveratrol can be used for human cancer prevention or therapy.
In this paper, a minimally invasive dielectric sensor with a compact footprint of <inline-formula> <tex-math notation="LaTeX">24 \times 18 </tex-math></inline-formula> mm2 is presented. It is based ...on two complementary split ring resonators (CSRRs) fed by a microstrip with coplanar waveguide configuration and placed on a <inline-formula> <tex-math notation="LaTeX">200 \mu \text{m} </tex-math></inline-formula> thick Kapton substrate. The device has been fabricated by means of a multi-material 3D printer NanoDimension's Dragonfly IV and is characterized by exploiting two different sensing methodologies. As a first step, the device has been characterized in the air by measuring the volume of deionized water droplets placed on one of the CSRRs in the range between <inline-formula> <tex-math notation="LaTeX">3.6 \mu \text{l} </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">9.6 \mu \text{l} </tex-math></inline-formula>. This study has been performed through the analysis of the resonant frequency shift caused by the variation of the dielectric constant. The results show a Q-factor of 702 and a sensitivity of 0.3% <inline-formula> <tex-math notation="LaTeX">\mu \text{l}^{-1} </tex-math></inline-formula>. Then, an additional step has been carried out for the measurement of the temperature of the water in which the sensor is totally dipped. We analyzed the frequency shift due to the water temperature variation in the range between 20°C and 40°C which corresponds to a variation in relative permittivity. In this case, the sensor shows remarkable results in terms of Q-factor, equal to 501, and a sensitivity to dielectric variations in out-of-body and in-body temperature ranges equal to 0.5% and 1.5%, respectively.
The majority of wearable and flexible 5G and 6G devices are based on plastic substrates, that are harmful to the environment. Therefore, the development of sustainable and plastic-free radio ...frequency (RF) devices becomes a crucial issue. In this regard, we present a fully biocompatible Planar Inverted-F Antenna (PIFA), fabricated on a <inline-formula> <tex-math notation="LaTeX">55 ~\mu \text{m} </tex-math></inline-formula>-thick chitosan substrate. Chitosan has a relative dielectric constant of 5. This antenna is working at 4.5 GHz in the sub-6 GHz band of the 5G spectrum. It has a very compact footprint of <inline-formula> <tex-math notation="LaTeX">14\times23 </tex-math></inline-formula> mm2 and a Specific Absorption Rate (SAR) of 0.41 W/kg. The prototype has been fabricated using an innovative fabrication protocol. A very good agreement between numerical and experimental results has been obtained. The measured realized gain is equal to 1 dBi at the resonant frequency. Our results demonstrate the suitability of chitosan as a dielectric substrate for the fabrication of plastic-free antennas and paves the way for the development of sustainable wearable devices for the Internet of Healthcare Things (IoHT) applications.
Ultraviolet-light (UV)-induced tanning is defective in numerous 'fair-skinned' individuals, many of whom contain functional disruption of the melanocortin 1 receptor (MC1R). Although this suggested a ...critical role for the MC1R ligand melanocyte stimulating hormone (MSH) in this response, a genetically controlled system has been lacking in which to determine the precise role of MSH-MC1R. Here we show that ultraviolet light potently induces expression of MSH in keratinocytes, but fails to stimulate pigmentation in the absence of functional MC1R in red/blonde-haired Mc1re/e mice. However, pigmentation could be rescued by topical application of the cyclic AMP agonist forskolin, without the need for ultraviolet light, demonstrating that the pigmentation machinery is available despite the absence of functional MC1R. This chemically induced pigmentation was protective against ultraviolet-light-induced cutaneous DNA damage and tumorigenesis when tested in the cancer-prone, xeroderma-pigmentosum-complementation-group-C-deficient genetic background. These data emphasize the essential role of intercellular MSH signalling in the tanning response, and suggest a clinical strategy for topical small-molecule manipulation of pigmentation.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The biomass steam gasification is a promising path to obtain hydrogen-rich syngas and to improve the global efficiency for cogeneration purposes.
The present study reports the results of a campaign ...of steam gasification tests performed in a bench-scale gasifier (0.1 m ID) housing in its freeboard a ceramic filter, in a temperature range of 800 °C–815 °C. Three new ceramic filters have been tested: (i) noncatalytic candle with new support, (ii) filter candle with catalytic layer, (iii) filter candle with new integrated catalytic foam system and results were compared to those obtained in tests without candle. The volume composition of the syngas was monitored and analyzed by online measurement by means of infrared – thermal conductivity detector (IR-TCD) facilities to evaluate the CO, CO2, CH4, H2, NH3 composition. The Topping Atmosphere Residue (tar) content was evaluated by gas-chromatograph mass spectrometer (GCMS) facility; gas yield, water conversion and char conversion were also calculated from direct measurements.
The best results were obtained in the case of innovative catalytic filter in association with cycled olivine bed, obtaining gas yield equal to 1.80 Nm3/kgdaf (vs 1.00 Nm3/kgdaf without candle); observed to theoretical water conversion ratio equal to 0.88 (vs 0.33); H2 volume content equal to 56% (vs 39%); total tar content equal to 0.14 g/Nm3 (vs 6 g/Nm3).
•Gas conditioning in H2 rich syngas production by biomass steam gasification.•Three innovative ceramic filter candles are experimentally compared.•Hydrogen content close 56% in the product gas is achieved.•Gas yield equal to 1.80 Nm3/kgdaf and good water conversion are obtained.•Optimal performance of catalytic candle integrated with catalytic foam is proven.
Planarian flatworms are best known for their impressive regenerative capacity, yet this trait varies across species. In addition, planarians have other features that share morphology and function ...with the tissues of many other animals, including an outer mucociliary epithelium that drives planarian locomotion and is very similar to the epithelial linings of the human lung and oviduct. Planarians occupy a broad range of ecological habitats and are known to be sensitive to changes in their environment. Yet, despite their potential to provide valuable insight to many different fields, very few planarian species have been developed as laboratory models for mechanism-based research.
Here we describe a previously undocumented planarian isolate, Girardia sp. (Guanajuato). After collecting this isolate from a freshwater habitat in central Mexico, we characterized it at the morphological, cellular, and molecular level. We show that Girardia sp. (Guanajuato) not only shares features with animals in the Girardia genus but also possesses traits that appear unique to this isolate. By thoroughly characterizing this new planarian isolate, our work facilitates future comparisons to other flatworms and further molecular dissection of the unique and physiologically-relevant traits observed in this Girardia sp. (Guanajuato) isolate.
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•G.sp (Guanajuato) is a new planarian isolate collected in Mexico.•G.sp (Guanajuato) is largely asexual and highly regenerative.•G.sp (Guanajuato) displays a unique mode of locomotion.•Head regeneration in G.sp (Guanajuato) is less robust than in S.mediterranea.•G.sp (Guanajuato) animals and their piwi-1+ stem cells exhibit increased radiation tolerance compared to S.mediterranea.
This paper presents an innovative, flexible and biocompatible Ultra High Frequency meander antenna, operating at about 800 MHz, realized by means of sputtering on a Polyethylene Naphthalate ...substrate, and by means of a multi-material 3D printer. The fabricated antennas were characterized in terms of scattering parameters, showing a good impedance matching and a bandwidth in the order of tens of megahertz, gain and 3D radiation patterns. A numerical model was also introduced to investigate the limits of the proposed technologies in terms of metal thicknesses. The fabricated antenna could be efficiently integrated with Surface Acoustic Wave resonators to realize compact, wireless, wearable and battery-less sensing platforms.
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•Design of wearable and flexible antennas.•Fabrication of antennas by means of Multi-material 3D printer.•Characterization of the proposed antennas at sub-1GHz frequencies.
Hydrogen is considered one of the most important energy vector of the future and fuel in transport sector. The Fuel Cells (FCs) Traction System present some advantages respect to the traditional ...traction engine, consisting in lower emissions and noise. The more suitable Fuel Cells in automotive applications are those that use Polymer Electrolyte Membrane (PEM). The main obstacles to the commercialization of PEM fuel cells are largely concerning the cost, mechanical weakness and low durability of the membranes with increasing temperature. This latter aspect in particular referring to the fact that water is present in the membranes, thereby limiting the operating temperature of a fuel cell, which on average is about 80 °C. This in turn results in lower performance of the fuel cells due to a slower kinetics of electrodes and essentially no CO tolerance. It can groped to improve the performance of a PEM increasing the temperature above 100 °C, changing the membrane type making it resistant to the natural increase in temperature of the system so as to improve the electrodes kinetics. The present work has the purpose of highlighting the orientation of the current research towards the development of specific types of membrane for the FC performance improvement.
•Parameters and objectives for polymer electrolyte membrane improvement.•Strategy for alternative proton conductive membrane development.•To overcome the fuel cell constrains PBI membranes deserve particular attention.
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