RESUMO
This study presents a grating interferometric acoustic sensor based on a flexible polymer diaphragm. A flexible-diaphragm acoustic sensor based on grating interferometry (GI) is proposed through design, fabrication and experimental demonstration. A gold-coated polyethylene terephthalate diaphragm was used for the sensor prototype. The vibration of the diaphragm induces a change in GI cavity length, which is converted into an electrical signal by the photodetector. The experimental results show that the sensor prototype has a flat frequency response in the voice frequency band and the minimum detectable sound pressure can reach 164.8 µPa/âHz. The sensor prototype has potential applications in speech acquisition and the measurement of water content in oil. This study provides a reference for the design of optical interferometric acoustic sensor with high performance.
RESUMO
A prototype optical bionic microphone with a dual-channel Mach-Zehnder interferometric (MZI) transducer was designed and prepared for the first time using a silicon diaphragm made by microelectromechanical system (MEMS) technology. The MEMS diaphragm mimicked the structure of the fly Ormia Ochracea's coupling eardrum, consisting of two square wings connected through a neck that is anchored via the two torsional beams to the silicon pedestal. The vibrational displacement of each wing at its distal edge relative to the silicon pedestal is detected with one channel of the dual-channel MZI transducer. The diaphragm at rest is coplanar with the silicon pedestal, resulting in an initial phase difference of zero for each channel of the dual-channel MZI transducer and consequently offering the microphone strong temperature robustness. The two channels of the prototype microphone show good consistency in their responses to incident sound signals; they have the rocking and bending resonance frequencies of 482 Hz and 1911 Hz, and their pressure sensitivities at a lower frequency exhibit an "8"-shaped directional dependence. The comparison indicates that the dual-channel MZI transducer-based bionic microphone proposed in this work is advantageous over the Fabry-Perot interferometric transducer-based counterparts extensively reported.
RESUMO
OBJECTIVE: To determine the effects of arsenic and estrogen receptor antagonist (ICI182, 780) on the expression of estrogen receptor beta (ERß) in alveolar â ¡ epithelial cells (AECâ ¡) of female and male mice. METHODS: Nineteen or twenty day fetus mice were obtained through caesarean section of ICR mice. Purified AECâ ¡ cells were separated from the female and male fetus,respectively,and confirmed using immunofluorescence staining. The cells were exposed to sodium arsenite (NaAsO2) at a low,medium,or high dosage determined by MTT and cultured for 24 h. The NaAsO2 (5 µmol/L) exposed cells were compared with those treated (for 24 h) with dimethyl sulfoxide (DMSO) or ICI182, 780 (1×10-4 mol/L). Apoptosis rates of the cells were measured by flow cytometry. Real-time fluorescence quantitative PCR method and Western blot technique were used to detect the expression ofERßmRNA and protein in AECâ ¡. RESULTS: Purity of AECâ ¡ cells reached (87.0±2.5)%. NaAsO2 exposure was set at a concentration of 0.5 (low),1.25 (medium),and 5 (high) µmol/L. The cells exposed to medium and high dosage of NaAsO2 had higher apoptosis rates than the blank controls (P<0.05),without sex differences. Female cells exposed to medium and high dosage of NaAsO2 had higher levels of expressions ofERßmRNA and protein than the blank controls (P<0.05) and male cells exposed to the same dosage of NaAsO2 (P<0.05). No significant differences were found in the expressions ofERßmRNA and protein between the exposed male cells and the blank controls. ICI182, 780 lowered the expression levels ofERßmRNA and protein in the female exposed cells (P<0.01). CONCLUSION: Arsenic exposure increases expressions of AECâ ¡'s ERß,more so in female cells than in male cells. This can be blocked by estrogen receptor antagonists.
Assuntos
Células Epiteliais Alveolares/metabolismo , Arsênio/toxicidade , Antagonistas do Receptor de Estrogênio/toxicidade , Receptor beta de Estrogênio/metabolismo , Fatores Sexuais , Células Epiteliais Alveolares/efeitos dos fármacos , Animais , Apoptose , Receptor alfa de Estrogênio , Feminino , Masculino , Camundongos , Camundongos Endogâmicos ICR , GravidezRESUMO
OBJECTIVES: To investigate the polymorphisms in interleukin 17A IL-17A) and interleukin 17F (IL-17F) and their relationship with pulmonary inflammation risk of dust exposed workers. METHODS: A case-control study among 193 subjects, including 67 subjects in case group and 126 in control group was conducted. PCR-RFLP was applied to genotype IL-17A (G-197A) and IL-17F (7488T/C). Logistic regression analysis was used to determine the effects of IL-17A (G-197A) and IL-17F (7488T/C) on the lung inflammation risk in dust exposed workers. RESULTS: The genotypes analysis showed that the proportions of IL-17A (G-197A) A/A, A/G and G/G were 42 (21.76%), 95 (49.22%), 56 (29.02%) in 193 cases, respectively, and the IL-17F (7488T/C) T/T, T/C and C/C genotypes were 128 (66.32%), 54 (28.98%), 11 (5.70%), respectively. The frequency distribution of each genotype was consistent with the Hardy-Weinberg equilibrium fixed law. The ratio of IL-17A (G-197A) A/A in the case group was lower than that of control group ( P<0.05), while the G/G and A/G genotypes were higher than that of control group ( P<0.05). Furthermore, the genotypes of IL-17A (G-197A) A/G (OR=5.03, P<0.01) and G/G(OR=3.35, P<0.05) were associated with an increased risk of lung inflammation in workers exposed to dust. The frequency distribution difference of IL-17F (7488T/C) T/T, T/C and C/C genotypes in the cases and control group was unobvious ( P>0.05). CONCLUSIONS: Under the same dust concentration, the dust exposed workers carrying IL-17A (G-197A) A/G, G/G genotypes are more susceptible to pulmonary inflammation in the southwest of China.