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Beta gallium oxide (β‐Ga2O3) has emerged as a highly promising semiconductor material with an ultrawide bandgap ranging from 4.5 to 4.9 eV for future applications in power electronics, optoelectronics, as well as gas and ultraviolet (UV) radiation sensors. Here, surface adsorption and air damping behavior of doubly clamped β‐Ga2O3 nanomechanical resonators are probed and systemically studied by measuring the resonance characteristics under different gas and pressure conditions. High responsivities of resonance to pressure are obtained by heating the devices up to 300 °C to induce an accelerated adsorption–desorption process. The initial surface conditions of the β‐Ga2O3 thin film play important roles in affecting the resonant behavior. UV ozone treatment proves effective in altering the initial surface conditions of β‐Ga2O3 nanosheets by eliminating physisorbed contaminants and filling oxygen vacancy defects residing on the surface, resulting in a consequential and discernible modification of the resonance behavior of β‐Ga2O3 nanomechanical resonators. The surface adsorption and desorption processes in β‐Ga2O3 demonstrate clear reversibility by exposing the UV treated β‐Ga2O3 to air. This study attains first‐hand information on how the surface conditions of β‐Ga2O3 affect its mechanical properties, and helps guide future development of transducers via β‐Ga2O3 nanoelectromechanical systems (NEMS) for pressure sensing applications, especially in harsh environments. [ABSTRACT FROM AUTHOR]

The experimental demonstration of aluminum scandium nitride (AlScN)‐on‐cubic silicon carbide (SiC) heterostructure thin film micromachined resonant transducers operating in a high‐temperature environment up to 600 °C is reported. Macroscopic and microscopic vibrations are investigated through a combination of ultrasensitive laser interferometry techniques and Raman spectroscopy. An average linear temperature coefficient of resonance frequency (TCf) of <1 ppm °C−1 within the temperature range from room temperature to 200 °C, and an average linear TCf of −16 ppm °C−1 between 200 and 600 °C, from the fundamental‐mode resonance of AlScN/SiC circular diaphragm resonator with a thickness of 1.9 µm and diameter of 250 µm, is obtained. Higher‐order modes exhibit much larger TCf, which make them strong candidates as high‐temperature‐tolerant temperature sensors or ultraviolet detectors. Raman spectroscopy indicates that the turning points of the peak positions of the longitudinal optical phonon modes of both 3C‐SiC and AlScN occur in almost the same temperature region where the turnover point of TCf is observed, suggesting that the microscopic vibrations in the crystal lattice and the macroscopic oscillation of the diaphragm are naturally mediated by the residual strain inside the materials at varying temperature. [ABSTRACT FROM AUTHOR]

Aim: This study aimed to determine whether periodontitis in early pregnancy and periodontal therapy during gestation affect the incidence of gestational diabetes mellitus (GDM) through a population‐based clinical study. Materials and methods: Subjects without periodontitis at 1–4 weeks of gestation who met our inclusion criteria were enrolled in the non‐periodontitis group. Periodontitis patients who agreed or refused to receive periodontal therapy during pregnancy were separately enrolled in the periodontitis treated or untreated group. At 12–16 weeks of gestation, gingival crevicular fluid (GCF) and venous blood were collected for analyses of bacterial species and serum inflammatory mediators, respectively. At 24–28 weeks of gestation, GDM patients were identified by oral glucose tolerance tests. The association tests were performed using Chi‐squared statistics and regression analyses. Results: The complete data of 3523 pregnant women were recorded during the study period. GDM incidence among the untreated periodontitis participants (84/749, 11.21%) was significantly higher than that among the non‐periodontitis participants (108/2255, 4.79%) (p <.05), and periodontal treatment during gestation reduced the incidence from 11.21% (untreated group) to 7.32% (38/519, treated group) (p <.05). Based on multiple logistic regression analyses, it was found that periodontitis in early pregnancy was associated with GDM, and three‐step regression analyses showed that Porphyromonas gingivalis (P. gingivalis) and the serum TNF‐α and IL‐8 levels played a role in the association between untreated periodontitis and GDM. Furthermore, Pearson's correlation test indicated that the existence of P. gingivalis in GCF was positively correlated with high serum levels of these two inflammatory mediators. Conclusions: This study establishes a connection between periodontitis in early pregnancy and GDM and demonstrates that the presence of P. gingivalis is associated with high levels of inflammatory mediators in serum, and thereby may contribute to the development of GDM. In‐depth mechanistic studies are needed to further support these findings. [ABSTRACT FROM AUTHOR]

A new phase shifter based on injection‐locked ring oscillator is proposed. By using a multi‐stage phase generator with voltage‐controlled injection locking technique, the proposed phase shifter is able to generate a flexible combination of coarse and fine‐tuned phase delays over a wide range of operating frequencies while a small silicon area is maintained. Fabricated in a 0.18 µm RF CMOS process which only occupies 50 × 40 µm, a proposed three‐stage phase shifter achieves flexible phase delays and a measured operating frequency up to 2 GHz with a maximum power consumption of 2 mW from a 1.8 V supply. [ABSTRACT FROM AUTHOR]

Background: Poor osseointegration of dental implants often occurs in osteoporotic patients and processed implant surfaces could help to improve the dilemma. Purpose: This study aimed to compare the effects of different titanium (Ti) surfaces on bone‐implant osseointegration in ovariectomized (OVX) sheep. Materials and Methods: Four groups were included: smooth titanium (ST) was merely polished Ti; micro titanium (MT) was treated with hydrofluoric acid (HF) for 30 minutes; strontium‐loaded nano titanium (NT‐Sr) was formed by magnetron sputtering; strontium‐loaded micro/nano titanium (MNT‐Sr) was fabricated by HF etching combined with magnetron sputtering. The biological responses were evaluated by human bone marrow‐derived mesenchymal stem cells (hBMMSCs) experiments in vitro. Osseointegration was evaluated in vivo after each surface implant was inserted into OVX sheep' mandibles. Results: The numbers of adhered and mineralized hBMMSCs increased significantly in the MNT‐Sr group. The bone‐implant contact and the maximal pull‐out force increased significantly with MNT‐Sr surface. The bone volume ratio and trabecular number of the MNT‐Sr group were significantly higher than others, whereas trabecular separation decreased. Conclusions: These results indicated that an MNT‐Sr surface promotes the differentiation of hBMMSCs in vitro and enhances bone‐implant osseointegration in vivo, which may be a promising option for clinical implants in osteoporotic patients. [ABSTRACT FROM AUTHOR]

We tested the hypothesis that the circadian clock modulates Ca2+-based signalling pathways, using low-temperature (LT)-induced Ca2+ signals. We investigated the relationship between diurnal and circadian modulation of LT-induced increases in cytosolic-free calcium ([Ca2+]cyt), and regulation of [Ca2+]cyt-dependent outputs of the LT-signalling network ( RD29A transcript abundance and stomatal closure). We measured [Ca2+]cyt non-invasively using aequorin, and targeted aequorin to the guard cell using a guard cell-specific GAL4-green fluorescent protein enhancer trap line. LT caused transient increases in whole plant and guard cell [Ca2+]cyt. In guard cells, the LT-induced [Ca2+]cyt elevation preceded stomatal closure. In whole plants, the magnitude of LT-induced [Ca2+]cyt transients, measured from the entire plant or specifically the guard cell, varied with the time of day: LT-induced [Ca2+]cyt transients were significantly higher during the mid-photoperiod than at the beginning or end. Diurnal variation in LT-induced guard cell [Ca2+]cyt increases was not correlated to diurnal variation in LT-induced stomatal closure. There was circadian modulation of LT-induced whole plant [Ca2+]cyt increases, which were correlated to the circadian pattern of RD29A induction. In order to understand the significance of LT-induced [Ca2+]cyt increases, we used a computer simulation to demonstrate that, in guard cells, LT-induced [Ca2+]cyt increases measured from a population of cells are likely to represent the summation of cold-induced single-cell [Ca2+]cyt oscillations. [ABSTRACT FROM AUTHOR]