Linear Displacement and Straightness Measurement by Fabry-Perot Interferometer Integrated with an Optoelectronic Module

This research develops a three degrees of freedom (DOF) measurement system by integrating Fabry-Perot interferometer and photoelectronic inspection module to determine linear displacement, horizontal and vertical straightness geometric error parameters simultaneously. The interferometer and the photoelectronic inspection module in a three DOF measurement system share the same light source, and the two structures are used to measure linear displacement and straightness errors. The experimental results are utilized to calculate the relevant error parameters according to ISO standards and numerical analysis. They show that after the machine error compensation, the positioning deviation of the system is reduced from 55 μm to 19 μm, corresponding to the reduction of 65%. The accuracy is promoted from 65 μm to 31 μm, about the improvement of 52%. The horizontal and vertical straightness errors of the machine are 4.30 μm and 5.71 μm respectively

Leveling Maintenance Mechanism by Using the Fabry-Perot Interferometer with Machine Learning Technology

This study proposes a method for maintaining parallelism of the optical cavity of a laser interferometer using machine learning. The Fabry-Perot interferometer is utilized as an experimental optical structure in this research due to its advantage of having a brief optical structure. The supervised machine learning method is used to train algorithms to accurately classify and predict the tilt angle of the plane mirror using labeled interference images. Based on the predicted results, stepper motors are fixed on a plane mirror that can automatically adjust the pitch and yaw angles. According to the experimental results, the average correction error and standard deviation in 17-grid classification experiment are 32.38 and 11.21 arcseconds, respectively. In 25-grid classification experiment, the average correction error and standard deviation are 19.44 and 7.86 arcseconds, respectively. The results show that this parallelism maintenance technology has essential for the semiconductor industry and precision positioning technology

Efficacy of pharmacologic treatment in tinnitus patients without specific or treatable origin: A network meta-analysis of randomised controlled trials

Background- Although tinnitus has a prevalence between 20 and 42.8%, the currently recommended management for tinnitus, such as tinnitus support and psychologic therapies, are relatively time-consuming and expensive. Several new pharmacologic treatments designed for tinnitus patients without specific origin had been developed but their efficacy remains unclear. Methods- The current Network Meta-Analysis (NMA) of randomised controlled trials (RCTs) was conducted to evaluate the efficacy of different pharmacologic treatments for tinnitus management in tinnitus patients without specific or treatable origin (i.e. primary tinnitus). Databases were searched from inception to April 5th, 2021. All network meta-analytic procedures were conducted under the frequentist model. We calculated the effect size of outcomes with different rating scales with standardized mean difference. PROSPERO registration: CRD42020177742. Findings- Overall, 36 RCTs were included with 2,761 participants. The main results revealed that pharmacologic interventions with brain-acting effect (for example, amitriptyline, acamprosate, and gabapentin) and those with anti-inflammation/anti-oxidant effect (for example, intra-tympanic dexamethasone injection plus oral melatonin) were associated with superior improvement in tinnitus severity and response rate compared to placebo/control. Oral amitriptyline were associated with the highest improvement in tinnitus severity and the fourth highest response rate. None of the investigated interventions was associated with different changes in quality of life compared to placebo/control. All the investigated treatments were associated with similar drop-out rate to placebo/control. Interpretation- The current NMA suggests a potential role for treatments with brain-acting effect (for example, amitriptyline, acamprosate, and gabapentin) or anti-inflammation/anti-oxidant effect (for example, intra-tympanic dexamethasone injection plus oral melatonin) as the preferable effective treatments for tinnitus without specific or treatable origin

Developing an Interferogram-Based Module with Machine Learning for Maintaining Leveling of Glass Substrates

In this research, we propose a method that utilizes machine learning to maintain the parallelism of the resonant cavity in a Fabry–Perot interferometer designed specifically for glass substrates. Based on the optical principle and theory, we establish a proportional relationship between interference fringes and the inclination angle of the mirrors. This enables an accurate determination of the inclination angle using supervised learning, specifically classification. By training a machine learning model with labeled data, interference fringe patterns are categorized into three levels, with approximately 100 training data available for each level in each location. The experimental results of Level 2 and Level 3 classification indicate an average number of corrections of 2.55 and 3.55 times, respectively, in achieving the target position with a correction error of less than 30 arc seconds. These findings demonstrate the essential nature of this parallelism maintenance technology for the semiconductor industry and precision mechanical engineering

Development of the Heterodyne Laser Encoder System for the X–Y Positioning Stage

This investigation develops a laser encoder system based on a heterodyne laser interferometer. For eliminating geometric errors, the optical structure of the proposed encoder system was carried out with the internal zero-point method. The designed structure can eliminate the geometric errors, including positioning error, straightness error, squareness error, and Abbe error of the positioning stage. The signal processing system is composed of commercial integrated circuits (ICs). The signal type of the proposed encoding system is a differential signal that is compatible with most motion control systems. The proposed encoder system is embedded in a two-dimensional positioning stage. By the experimental results of the positioning test in the measuring range of 27 mm × 27 mm, with a resolution of 15.8 nm, the maximum values of the positioning error and standard deviation are 12.64 nm and 126.4 nm, respectively, in the positioning experiments. The result shows that the proposed encoder system can fit the positioning requirements of the optoelectronic and semiconductor industries

Long-Term Ambient Air Pollutant Exposure and Risk of Recurrent Headache in Children: A 12-Year Cohort Study

Although studies have suggested environmental factors to be triggers of headache, the contribution of long-term air pollution exposure to recurrent headaches is poorly understood. Hence, we executed this nationwide cohort study to investigate associations between levels of ambient air pollutants and risks of recurrent headaches in children in Taiwan from 2000 to 2012. We used data from the Taiwan National Health Insurance Research Database and linked them to the Taiwan Air Quality Monitoring Database. Overall, 218,008 children aged < 18 were identified from 1 January 2000, and then followed until they were diagnosed by a physician for ≥3 times with recurrent headaches or until 31 December 2012. We categorized the annual average concentration of each air pollutant (fine particulate matter, total hydrocarbon, methane, sulfur dioxide, and nitrogen dioxide) into quartiles (Q1–Q4). We measured the incidence rate, hazard ratios (HRs), and the corresponding 95% confidence intervals for recurrent headaches. stratified by the quartiles. A total of 28,037 children (12.9%) were identified with recurrent headaches. The incidence rate and adjusted HR for recurrent headaches increased with higher-level exposure of air pollutants, except sulfur dioxide. We herein demonstrate that long-term ambient air pollutant exposure might be a risk factor for childhood recurrent headaches

Enhancement in the solar efficiency of a dye-sensitized solar cell by molecular engineering of an organic dye incorporating N-alkyl-attached 1,8-naphthalamide derivative

Controlling the orientation of the dye molecules adsorbed on the TiO2 surface needs extensive attention for improving the photovoltaic parameters of dye-sensitized solar cells (DSSCs). The suppression of the charge recombination and self-aggregation of dye molecules on the TiO2 surface also plays a vital role in the improvement of cell efficiency. In this report, based on the bi-anchored structure containing N-alkyl-attached 1,8-naphthalamide derivative as the donor system and spiroBiproDOT as the π-spacer, an organic dimeric dye (D-Dye) was designed and synthesized by Suzuki coupling, followed by Knoevenagel condensation. The maximum power conversion efficiency of 7.1% with a Voc and Jsc of 0.70 V and 14.6 mA cm−2, respectively, was achieved for the DSSC employing D-Dye. A monomeric dye (M-Dye) was also synthesized and the resultant cell efficiency of 4.85% was achieved with Voc and Jsc of 0.67 V and 9.93 mA cm−2, respectively, which was 33% lower than that of its dimeric analogue (D-Dye). The photo-physical experiment was carried out for both organic dyes to understand their light absorption characteristics. The incident photon-to-current conversion efficiency (IPCE) and electrochemical impedance measurements were also obtained to rationalize the better photovoltaic performance of DSSCs employing the dimeric D-Dye, which was due to the effective suppression of the charge recombination and self-aggregation of dye molecules. The co-adsorption of D-Dye (0.4 mM) with N-719 (0.4 mM) in the ratio of 10 : 1 v/v (D-Dye:N-719) further enhanced the cell efficiency to 8.34% (Voc of 0.77 V and Jsc of 14.9 mA cm−2)

Low-Energy Extracorporeal Shock Wave Ameliorates Streptozotocin Induced Diabetes and Promotes Pancreatic Beta Cells Regeneration in a Rat Model

Traditional therapy for diabetes mellitus has focused on supportive treatment, and is not significant in the promotion of pancreatic beta cells regeneration. We investigated the effect of low- energy extracorporeal shock wave (SW) on a streptozotocin induced diabetes (DM) rat model. Methods: The DM rats were treated with ten sessions of low-energy SW therapy (weekly for ten consecutive weeks) or left untreated. We assessed blood glucose, hemoglobin A1c (HbA1c), urine volume, pancreatic islets area, c-peptide, glucagon-like peptide 1 (GLP-1) and insulin production, beta cells number, pancreatic tissue inflammation, oxidative stress, apoptosis, angiogenesis, and stromal cell derived factor 1 (SDF-1) ten weeks after the completion of treatment. Results: The ten- week low-energy SW therapy regimen significantly reduced blood glucose, HbA1c, and urine volume as well as significantly enhancing pancreatic islets area, c-peptide, GLP-1, and insulin production in the rat model of DM. Moreover, low-energy SW therapy increased the beta cells number in DM rats. This was likely primarily attributed to the fact that low-energy SW therapy reduced pancreatic tissue inflammation, apoptosis, and oxidative stress as well as increasing angiogenesis, cell proliferation, and tissue repair potency. Conclusions: Low-energy SW therapy preserved pancreatic islets function in streptozotocin-induced DM. Low-energy SW therapy may serve as a novel noninvasive and effective treatment of DM

In Vivo Evaluation of PVP-Gelatin-Chitosan Composite Blended with Egg-Yolk Oil for Radiodermatitis

Radiation-induced skin injury (RSI) is a frequent complication of radiotherapy. Severe cases affect the patient’s disease treatment and quality of life. The main purpose of this study is to examine the causative role of egg-yolk oil (EYO) in delayed radiation-induced skin injury, including impaired wound healing. Using polyvinyl pyrrolidone (PVP)-gelatin-chitosan (PGC) composite film as controlled release of egg-yolk oil (EYO) was studied in rats, which were used as a radiation-induced skin injury model. Different composition ratios were tested for their mechanical properties, moisture content, and degradation characteristics. The results showed that the PGC112 (w/w) substrate, which will hence be referred to as PGC, had the better properties. Further, the PGC was mixed with EYO (0.25% and 0.5%) to prepare the films (PGC/0.25EYO and PGC/0.5EYO, respectively). Furthermore, the mechanical and degradation properties and biocompatibility showed better results with PGC/0.5EYO. In animal studies, rats were irradiated with single-dose electron beams of 40 Gy. The animals were divided into five groups to perform wound treatment with various types of wound dressing for 30 days. Histological examination and CD68 immunochemical staining were then conducted, and observations were made. The results showed that PGC/0.5EYO has a significantly healing effects on radiodermatitis and good re-epithelialization

Enhancement of power conversion efficiency of dye-sensitized solar cells for indoor applications by using a highly responsive organic dye and tailoring the thickness of photoactive layer

Dye-sensitized solar cells (DSSCs) based on different configurations under various light intensity are characterized, where commercial N719 dye and synthesized D-Dye are used as photo-sensitizer. Regardless of cell configuration, organic D-Dye serves as an efficient photo-sensitizer, giving rise to high cell efficiency comparable with N719. The highest efficiency of 20.98% (Voc of 0.6 V, Jsc of 0.62 mA/cm2, FF of 0.71) is achieved as the front-illuminated rigid DSSC is constructed by applying 8 μm TiO2 layer under 6000 LUX illumination. At the same condition the efficiency of 19.69% (Voc of 0.63 V, Jsc of 0.57 mA/cm2, FF of 0.74) is recorded for N719. Higher efficiency for D-Dye is attributed to high response of its absorption spectrum to the emission spectrum of indoor T5 irradiance. Charge transfer resistance is measured to be 53.1 Ω for D-Dye in conjunction with 8 μm TiO2 which is higher than thicker TiO2 (10 μm and 12 μm) at 0.75 V applied bias under dark condition, indicating that reduction of TiO2 thickness facilitates charge transfer by suppressing charge recombination under low illuminations. A systematic study of the efficiency as a function of key factors like TiO2 thickness, electrode type, and light intensity is explored