A Microwave Pressure Sensor Loaded with Complementary Split Ring Resonator for High-Temperature Applications.

A passive substrate integrated waveguide (SIW) sensor based on the complementary split ring resonator (CSRR) is presented for pressure detection in high-temperature environments. The sensor pressure sensing mechanism is described through circuit analysis and the electromagnetic coupling principle. The pressure sensor is modeled in high frequency structure simulator (HFSS), designed through parameter optimization. According to the optimized parameters, the sensor was customized and fabricated on a high temperature co-fired ceramic (HTCC) substrate using the three-dimensional co-fired technology and screen-printing technology. The pressure sensor was tested in the high-temperature pressure furnace and can work stably in the ambient environment of 25-500 °C and 10-300 kPa. The pressure sensitivity is 139.77 kHz/kPa at 25 °C, and with increasing temperature, the sensitivity increases to 191.97 kHz/kPa at 500 °C. The temperature compensation algorithm is proposed to achieve accurate acquisition of pressure signals in a high-temperature environment.

Wireless Passive Microwave Antenna-Integrated Temperature Sensor Based on CSRR.

A novel, wireless, passive substrate-integrated waveguide (SIW) temperature sensor based on a complementary split-ring resonator (CSRR) is presented for ultra-high-temperature applications. The temperature sensor model was established by using the software of HFSS (ANSYS, Canonsburg, PA, USA) to optimize the performance. This sensor can monitor temperature wirelessly using the microwave backscatter principle, which uses a robust high-temperature co-fired ceramic (HTCC) as the substrate for harsh environments. The results are experimentally verified by measuring the S (1,1) parameter of the interrogator antenna without contact. The resonant frequency of the sensor decreases with the increasing temperature using the dielectric perturbation method, which changes from 2.5808 to 2.35941 GHz as the temperature increases from 25 to 1200 °C. The sensitivity of the sensor is 126.74 kHz/°C in the range of 25-400 °C and 217.33 kHz/°C in the range of 400-1200 °C. The sensor described in this study has the advantages of simple structure, higher quality and sensitivity, and lower environmental interference, and has the potential for utilization in multi-site temperature testing or multi-parameter testing (temperature, pressure, gas) in high-temperature environments.

Dimension Reduction Localization Algorithm of Mixed Sources Based on MEMS Vector Hydrophone Array.

In this paper, a mixed sources dimension reduction Multiple Signal Classification (MUSIC) localization algorithm suitable for Micro-Electro-Mechanical System (MEMS) vector hydrophone linear arrays is proposed, which reduces the two-dimensional search to one-dimensional local search. Firstly, the Lagrangian function is constructed by quadratic optimization idea to obtain the estimates of azimuth angles. Secondly, the least square method is utilized for optimal match to obtain the direction-of-arrivals (DOAs) and ranges, and the range parameters are judged in Fresnel zone to obtain the azimuth information of all near-field sources. Finally, find the common DOAs and achieve high-resolution separation of far-field and near-field sources. Simulation and field experiments prove that the proposed algorithm only needs a small number of elements can solve the problem of port and starboard ambiguity, does not need to construct high-order cumulants or multi-dimensional search while the parameters are automatically matched with low computational complexity. This study provides an idea of the engineering application of vector hydrophone.

Study on the role of pyroptosis in bone resorption induced by occlusal trauma with or without periodontitis.

BACKGROUND AND OBJECTIVE: Occlusal trauma is considered to be a contributing factor to bone loss associated with inflammatory periodontal disease. We hypothesized that pyroptosis, a recently discovered inflammation-induced programmed cell death pathway, plays a role in occlusal trauma. MATERIALS AND METHODS: The occlusal trauma model was established using a cemented 1-mm elevated computer-aided design and manufacturing (CAD/CAM) metal crown. The periodontitis model was established by periodontal wire ligation with lipopolysaccharide (LPS) injection. The rats were sacrificed at 1, 2, 3, and 4 weeks. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze the expression of pyroptosis-, inflammation-, and osteoclast-related markers. Micro-computed tomography (micro-CT) was used to determine bone morphology parameters. Tissue morphology was evaluated using hematoxylin and eosin staining (H&E). Osteoclasts were identified using tartrate-resistant acid phosphatase (TRAP) staining. The expression and distribution of factors related to pyroptosis and inflammation were evaluated by immunohistochemistry (IHC). The colocalization of dead cells and cysteinyl aspartate-specific proteinase-1 (caspase-1)-positive cells was analyzed by immunofluorescence. RESULTS: Quantitative real-time polymerase chain reaction and IHC results showed that occlusal trauma induced the expression of pyroptotic factors during the early stages, while occlusal trauma with periodontitis upregulated the expression of pyroptotic factors at the later stages. The results of qRT-PCR, TRAP staining, and micro-CT showed that occlusal trauma with periodontitis increased the production of proinflammatory cytokines, leading to severe bone loss. Glyburide, an NOD-like receptor pyrin domain containing protein 3 (NLRP3)inhibitor, reduced the expression of pyroptosis markers induced by occlusal trauma with periodontitis and reversed bone resorption. CONCLUSIONS: Pyroptosis was involved in bone loss induced by occlusal trauma with or without periodontitis, while glyburide reversed inflammation and bone resorption.

Stability-Enhanced Emission Based on Biophotonic Crystals in Liquid Crystal Random Lasers.

A new design of a bio-random laser based on a butterfly wing structure and ITO glass is proposed in this article. Firstly, the butterfly wing structure was integrated in a liquid crystal cell made of ITO glass. The integrated liquid crystal cell was injected with liquid crystal and dye to obtain a bio-random laser. A non-biological random laser was obtained with a capillary glass tube, liquid crystal and dye. The excitation spectra and thresholds were recorded to evaluate the performance of the biological and non-biological random lasers. The results show that the excitation performance stability of the bio-random laser is improved and the number of spikes in the spectra is reduced compared with the non-biological random laser. Finally, the equivalent cavity length of the biological and non-biological random lasers was compared and the optical field distribution inside the butterfly wing structure was analyzed. The data show that the improvement of the excitation performance stability of the bio-random laser is related to the localization of the optical field induced by the photonic crystal structure in the butterfly wing.

Research on DOA Estimation Based on Acoustic Energy Flux Detection Using a Single MEMS Vector Hydrophone.

The principle of acoustic energy flux detection method using a single micro electromechanical system (MEMS) vector hydrophone is analyzed in this paper. The probability distribution of acoustic energy flux and the weighted histogram algorithm are discussed. Then, an improved algorithm is proposed. Based on the algorithm, the distribution range of the energy is obtained by a sliding window, the energy center of gravity in the range is considered as the result of direction of arrival (DOA) estimation, and it is proved to be the maximum likelihood estimation of the target direction. The simulation results show that, with the signal to noise ratio (SNR) from -10 dB to 10 dB, the root mean square error (RMSE) of the improved algorithm is reduced by 47.8% on average, and is more accurate in the presence of interference. The experimental results of lake test are consistent with the theory analysis and simulation results.

Freestanding symmetrical SiN/Si/SiN composite coated on carbon nanotube paper for a high-performance lithium-ion battery anode based on synergistic effects.

Direct coating of Si on an elastic carbon nanotube (CNT) network effectively addresses the rapid capacity fading of the Si anode. However, this strategy is hindered by the low Si tap density (Si < 50 nm) since sufficient void space has to be left for accommodating the Si volume change. Also, the mechanical properties of the CNT network as the elastic buffer matrix degrade significantly caused by side reactions of CNT with electrolyte. This work presents a freestanding paper-like anode consisting of a symmetrical sandwich-structured SiN/Si/SiN composite grown on CNT paper. This anode works well (∼259 µA h cm-2 under the current rate of 0.6C after 350 cycles, with a capacity retention of 73.8%) even when the CNT is filled by the composite without void space left for accommodating volume expansion. This is mainly due to the following synergistic effects: on one hand, the stress-compensation phenomenon in the symmetrical sandwich-structured composite balances the volume change-induced stress and thus the composite has a robust mechanical stability with an intact morphology during cycling. On the other hand, the intact composite avoids reaction of CNT with the electrolyte and thus the CNT retains excellent mechanical properties and serves well as the elastic buffer matrix. These two sides interact with each other, enabling the high anode performance.

Quality of Life of Implant-Supported Overdenture and Conventional Complete Denture in Restoring the Edentulous Mandible: A Systematic Review.

OBJECTIVE: The aim of this systematic review was to evaluate the oral health-related quality of life (OHRQoL) associated with an implant-supported overdenture (IOD) compared with a conventional complete denture (CCD) in restoring the edentulous mandible. METHODS: A literature search was performed in the MEDLINE (through Ovid), PubMed, and Cochrane Library databases for articles published between 1990 and July 2016. The search was restricted to articles published in English. Two reviewers selected the articles based on the inclusion and exclusion criteria. Another 2 reviewers analyzed the data. RESULTS: From 108 articles that were obtained, 5 articles met the inclusion criteria. Four studies had a high risk of bias, and 1 study had an unclear risk of bias. There was a significant difference in Oral Health Impact Profile (OHIP) scores between pre- and post-treatment within the groups and in posttreatment OHIP scores between IOD and CCD groups. CONCLUSION: Regarding the edentulous mandible, patients benefited more from the IOD with 2 implants, as determined by OHRQoL scores. Considering the differences between each domain of the Oral Health Impact Profile (OHIP) questionnaire and the lack of long-term performance, more random control trials with sufficient sample sizes need to be designed to investigate long-term performance after treatment.

[Marginal bone loss around tissue level implants in the posterior part of the mandible].

OBJECTIVE: To clarify the related factors of marginal bone loss (MBL) around tissue level implants in the posterior part of the mandible. METHODS: A total of 116 tissue level implants were implanted in the mandibular posterior region of 76 patients. Patients' information, including general characteristics, implant characteristics, implant site characteristics, and prosthesis characteristics, was recorded. Their cone beam computed tomography data were measured immediately after implant placement, 3 months later, and 3 and 12 months after prosthesis loading. The measurement of MBL was conducted by One Volume Viewer software. SPSS 20.0 was used for statistic analysis. RESULTS: Smoking, cortical bone thickness (CBT), collum angle (CA), and implant local sanitation showed significant differences with body mass loss (P<0.05). No significant differences were found among sex, age, length of implant, diameter of implants, implant systems, bone height, prosthesis type, and MBL (P>0.05). CONCLUSION: The risk factors that caused MBL were smoking, thicker CBT, larger CA, and poor implant local sanitation. Among them, poor implant local sanitation had the highest correlation with MBL.

Low-Threshold and High Intensity Random Lasing Enhanced by MnCl2.

Energy transfer is known to have a significant influence on random lasers. However, the study about the effect of energy transfer between metallic salt and dye molecules on random lasers is still lacking at present. Here, we investigate random lasing actions in Pyrromethene-597 (PM597), PM597-doped MnCl2 (manganese (II) chloride), PM597-doped polymer-dispersed liquid crystal (PDLC) and PM597-doped PDLC with MnCl2 capillary systems. We find that random lasing of the systems with MnCl2 exhibits lower threshold, higher intensity, sharper peak and variable resonance wavelength in comparison with the systems without MnCl2. This behavior is closely related to the decrease of fluorescence quenching effect and the enhancement of local field induced by energy transfer between MnCl2 and PM597. Red-shift of wavelength is observed with increasing dosage concentration of MnCl2 in the PM597-doped PDLC with MnCl2 system. Through the analysis of single-shot emission spectra of PM597-doped PDLC without and with MnCl2 systems, the role of MnCl2 in the coupling of lasing modes is confirmed. Lengths of laser oscillation cavities of the PM597-doped PDLC without and with MnCl2 systems are calculated by a power Fourier transform (PFT) analysis of their emission spectra. It well accounts for the effect of MnCl2 on the variation of the oscillation cavity.

Differentially expressed genes and signalling pathways are involved in mouse osteoblast-like MC3T3-E1 cells exposed to 17-ß estradiol.

Oestrogen is essential for maintaining bone mass, and it has been demonstrated to induce osteoblast proliferation and bone formation. In this study, complementary DNA (cDNA) microarrays were used to identify and study the expression of novel genes that may be involved in MC3T3-E1 cells' response to 17-ß estradiol. MC3T3-E1 cells were inoculated in minimum essential media alpha (α-MEM) cell culture supplemented with 17-ß estradiol at different concentrations and for different time periods. MC3T3-E1 cells treated with 10⁻8 mol⋅L⁻¹ 17-ß estradiol for 5 days exhibited the highest proliferation and alkaline phosphatase (ALP) activity; thus, this group was chosen for microarray analysis. The harvested RNA was used for microarray hybridisation and subsequent real-time reverse transcription polymerase chain reaction (RT-PCR) to validate the expression levels for selected genes. The microarray results were analysed using both functional and pathway analysis. In this study, microarray analysis detected 5403 differentially expressed genes, of which 1996 genes were upregulated and 3407 genes were downregulated, 1553 different functional classifications were identified by gene ontology (GO) analysis and 53 different pathways were involved based on pathway analysis. Among the differentially expressed genes, a portion not previously reported to be associated with the osteoblast response to oestrogen was identified. These findings clearly demonstrate that the expression of genes related to osteoblast proliferation, cell differentiation, collagens and transforming growth factor beta (TGF-ß)-related cytokines increases, while the expression of genes related to apoptosis and osteoclast differentiation decreases, following the exposure of MC3T3-E1 cells to α-MEM supplemented with 17-ß estradiol. Microarray analysis with functional gene classification is critical for a complete understanding of complementary intracellular processes. This microarray analysis provides large-scale gene expression data that require further confirmatory studies.

The early phase response of rat alveolar bone to traumatic occlusion.

OBJECTIVES: Occlusal trauma is an important factor to influence alveolar bone remodelling, the effect of which includes many cytokines and signalling pathways. However, the exact mechanism of the traumatic stimulus for alveolar remodelling is still unclear. The purpose of the present study was to investigate the early responses of alveolar osteocytes to occlusal trauma through genome-wide microarray. METHODS: The occlusal surface of the upper left first molar of rat was raised by placing a stainless steel wire to induce occlusal trauma in the lower left first molar. After 24 h, we took out the alveolar bone tissue of the first molars at the both sides of rats' lower jaws under anaesthesia. The different gene expressions were showed by genome-wide microarray, which comprises about 27,000 genes and the results were examined by quantitative RT-PCR. RESULT: Of the approximately 27,000 genes, the expression of 586 genes was strongly changed. These findings clearly demonstrated that in the early response of the alveolar bone to occlusal trauma, the expression of osteoblast, collagens, bone mineralization, bone remodelling and WNT, TGF-ß pathway related cytokines decreased, and osteoclast-specific cytokines have no significant changes in expression. CONCLUSION: These results suggested that at early phase of the occlusal trauma, osteogenesis in rat's alveolar bone was inhibited, and osteoclastogenesis was not significant.