Although thinning hair and alopecia are not recognized as severe diseases, hair loss has implications for mental health and quality of life; therefore, a large number of studies have been carried out to develop novel hair growth agents. In the present study, we aimed to examine the potential of telomerase reverse transcriptase (TERT), because TERT overexpression in skin activates resting hair follicle bulge stem cells, which triggers initiation of a new hair follicle growth phase and promotes hair synthesis. To this end, we screened polyphenols that activate TERT expression in keratinocytes, and identified resveratrol and fisetin as strong hTERT-augmenting compounds. These polyphenols also regulated the gene expression of cytokines such as IGF-1 and KGF, which activate the β-catenin pathway, and TGF-β1, which plays an important role in maintaining the niche of hair follicle stem cells, thus are thought to play roles in promoting hair growth. We additionally showed that these polyphenols, especially fisetin, promoted hair growth from the shaved dorsal skin of mice, which suggests that these polyphenols activate the transition from telogen to anagen phase. Histological studies indicated that the dorsal skin of mice treated with these polyphenols contained numerous hair follicles and was thickened compared with that in control mice. Furthermore, on the dorsal skin of mice treated with resveratrol and fisetin, a number of proliferating cells (Ki67 + cells) were observed around the hair papilla. These results suggest that resveratrol and fisetin induce a shift from telogen to anagen in the hair follicle by inducing proliferation of hair follicle bulge stem cells, thus promoting hair growth.

¹1 at low P p (0.06) at 77 K, indicator of high industrial reliability of production process, was 0.33 MGy, which was more than 3.7 times broader than that at 298 K. Based on the 3-parameter Weibull equation, the lowest o F p value at P p of zero (F s ) could be estimated. The 0.22 MGy-HLEBI at 77 K apparently improves the F s , which was higher than that 0.22 MGy-HLEBI at 298 K. Decreasing the irradiation temperature from 298 to 77 K controlled the rapid adhesion and rapid decay of adhesion at low-P p , which were mainly caused by the low forming ability of dangling bonds induced by strong apparent bonding force, which is related to decreasing atoms vibration energy. Since the 0.22 MGy-HLEBI at 77 K controlled the recovery of dangling bonds and generated the chemical bonds, the strong adhesive force of PTFE/PDMS treated by 0.22 MGy-HLEBI at 77 K could be explained. Therefore, HLEBI under liquid nitrogen was useful tool for quick strong PTFE/PDMS lamination with sterilization for bio-adaptable application.

Adhesive 2-layer lamination joints of polyethylene terephthalate (PET)/epoxy resin were prepared without the use of hot press using a new adhesion method of applying homogeneous low energy electron beam irradiation (HLEBI) to the PET prior to assembly by hand pressure. HLEBI treatment within the range of 0.13 to 0. , which were more than 2.2, 2.8 and 9.5 times larger than 5.76, 13.5 and 20.0 Nm ¹1 of the untreated at low-, median-and high peeling force accumulative probability, P p of 0.06, 0.50 and 0.94, respectively. The statistically lowest o F p for safety design (F s at P p = 0) iterated by the 3-parameter Weibull equation was raised from zero for the untreated to 10.7 Nm ¹1 for the 0.30 MGy samples indicating increased reliability by the HLEBI. XPS (X-Ray Photoelectron Spectroscopy) observations of the peeled 0.30 MGy HLEBI PET revealed generation of a C-O peak at 286 eV possibly explaining the increased adhesion. Therefore residual epoxy deposition is apparently found to be retained on the PET sheet by inter-matrix fracture of epoxy resin further into the thickness. This can be explained by the adhesion force from crosslinking between PET/epoxy being stronger than the cohesive force of epoxy polymer itself. Since the experimental data shows the optimum HLEBI dose is about 0.30 MGy, above which at 0.43 MGy the o F p begins to drop, carefulness in optimization is highly recommended when applying in industry to insure safety.

The effects of homogeneous low energy (170 keV) electron beam irradiation (HLEBI) on the adhesion force indicated by peeling resistance (o F p) at each accumulative probability of peeling resistance (P p) of laminated sheets of carbon fiber reinforced epoxy polymer (CFRP) and polytetrafluoroethylene (PTFE) were investigated. The slight detectable adhesive force of o F p before treatment were 0.3 and 7.6 Nm ¹1 at low and mid P p of 0.06 and 0.50, respectively, since the intermolecular attractive force exists at PTFE and epoxy polymers at cross-linking zone. Although additional dose of HLEBI apparently reduced the o F p of laminated sheets irradiated at more than 0.30 MGy as usual radiation damages, small dose of 0.04 to 0.22 MGy-HLEBI increased the adhesive force of peeling (o F p) substantially over the untreated. 0.13 MGy-HLEBI enhanced the o F p up to the largest values of 9.8 and 44.0 Nm ¹1 , respectively, which were more than 30.5 and 5.8 times larger than those before treatment. Based on the 3-parameter Weibull equation, the statistically lowest o F p value at P p = 0 (F s) was increased from zero to 9.2 Nm ¹1 by applying the 0.13 MGy HLEBI. XPS (X-ray photoelectron spectrometry) measurements detected the fluorine (1s) signal on peeled surface of CFRP side indicating the residual PTFE adhered well to the epoxy of CFRP by the HLEBI. Thus, the fracture probably propagated through the PTFE inside near cross-linking zone of interface. This is probably a result of adhesion force of PTFE/CFRP being made stronger than the cohesive force of epoxy polymer. When HLEBI cut the chemical bonds and generated active terminated atoms with dangling bonds of Epoxy and PTFE polymers in cross-linking zone with chemical bonding around adhesive interface, strengthening the adhesive force indicated by o F p was mainly induced by the chemical bonding, as well as intermolecular attractive force in cross-linking polymers.

A 2-layer aluminum/polycarbonate (Al/PC) joint was fabricated between half specimens of typically dif cult to adhere Al and PC without use of welding, fasteners, rivets, chemical treatment or glue by a new double-step adhesion method: applying a low dose of homogeneous low energy electron beam irradiation (HLEBI) to only the PC connecting surface, prior to lamination assembly and hot press at 418 K for 3.0 min under 15 MPa pressure. Experimental results showed 0.30 MGy along with 0.22 MGy had adhesion created in all 11 samples of their data sets [11/11], although data sets of untreated (hot press alone), 0.04, 0.13 and 0. . Based on the 3-parameter Weibull equation, the statistically lowest o F p at P p = 0 (F s ) from 0.30 MGy-HLEBI was the highest value over all other data sets at 3.10 N·m . XPS (X-ray photoelectron spectroscopy) of the peeled Al side revealed a C(1s) peak shift in binding energy from 283.8 eV (C-C) to 284.3 eV (C=C), along with increase in O(1s) C=O peak intensity (531.8 eV) indicating the 0.30 MGy HLEBI generates increased reactive double bond (π-bond) sites which can explain stronger o