Multi-Point Optical Fiber Fabry-Perot Curvature Sensor Based On Microwave Photonics

This article reports a multi-point curvature sensor system based on multiplexed optical fiber Fabry-Perot interferometric (FPI) sensor devices and a microwave photonics interrogation technique. The FPI sensor is fabricated with the assistance of a capillary tube, where a short section of the capillary is sandwiched between two single-mode fibers, forming the airgap Fabry-Perot cavity. Bending of the FPI device leads to changes in the fringe contrast of its reflection spectrum. Based on the microwave photonics filtering technique, variations of the fringe contrast are encoded into the changes in the peak magnitude of the passband in the frequency response of the FPI device. By multiplexing such FPI devices with different cavity lengths, multi-point measurements of curvature can be realized by tracking changes in corresponding passbands in the frequency response of the system. The FPI curvature sensor is easy-to-manufacture and cost-effective, and the microwave photonics-based system provides an alternative and robust solution to interrogating the multiplexed FPI sensors for multi-point curvature sensing that could be desired in structural health monitoring, human-machine interface sensing, and other related fields

Advances in Fiber-Optic Extrinsic Fabry-Perot Interferometric Physical and Mechanical Sensors: A Review

Fabry-Perot Interferometers Have Found a Multitude of Scientific and Industrial Applications Ranging from Gravitational Wave Detection, High-Resolution Spectroscopy, and Optical Filters to Quantum Optomechanics. Integrated with Optical Fiber Waveguide Technology, the Fiber-Optic Fabry-Perot Interferometers Have Emerged as a Unique Candidate for High-Sensitivity Sensing and Have Undergone Tremendous Growth and Advancement in the Past Two Decades with their Successful Applications in an Expansive Range of Fields. the Extrinsic Cavity-Based Devices, I.e., the Fiber-Optic Extrinsic Fabry-Perot Interferometers (EFPIs), Enable Great Flexibility in the Design of the Sensitive Fabry-Perot Cavity Combined with State-Of-The-Art Micromachining and Conventional Mechanical Fabrication, Leading to the Development of a Diverse Array of EFPI Sensors Targeting at Different Physical Quantities. Here, We Summarize the Recent Progress of Fiber-Optic EFPI Sensors, Providing an overview of Different Physical and Mechanical Sensors based on the Fabry-Perot Interferometer Principle, with a Special Focus on Displacement-Related Quantities, Such as Strain, Force, Tilt, Vibration and Acceleration, Pressure, and Acoustic. the Working Principle and Signal Demodulation Methods Are Shown in Brief. Perspectives on Further Advancement of EFPI Sensing Technologies Are Also Discussed

Imaging defects and their evolution in a metal–organic framework at sub-unit-cell resolution

© 2019, The Author(s), under exclusive licence to Springer Nature Limited. Defect engineering of metal–organic frameworks (MOFs) offers promising opportunities for tailoring their properties to specific functions and applications. However, determining the structures of defects in MOFs—either point defects or extended ones—has proved challenging owing to the difficulty of directly probing local structures in these typically fragile crystals. Here we report the real-space observation, with sub-unit-cell resolution, of structural defects in the catalytic MOF UiO-66 using a combination of low-dose transmission electron microscopy and electron crystallography. Ordered ‘missing linker’ and ‘missing cluster’ defects were found to coexist. The missing-linker defects, reconstructed three-dimensionally with high precision, were attributed to terminating formate groups. The crystallization of the MOF was found to undergo an Ostwald ripening process, during which the defects also evolve: on prolonged crystallization, only the missing-linker defects remained. These observations were rationalized through density functional theory calculations. Finally, the missing-cluster defects were shown to be more catalytically active than their missing-linker counterparts for the isomerization of glucose to fructose

Performance of 3D printed porous polyetheretherketone composite scaffolds combined with nano-hydroxyapatite/carbon fiber in bone tissue engineering: a biological evaluation

Polyetheretherketone (PEEK) has been one of the most promising materials in bone tissue engineering in recent years, with characteristics such as biosafety, corrosion resistance, and wear resistance. However, the weak bioactivity of PEEK leads to its poor integration with bone tissues, restricting its application in biomedical fields. This research effectively fabricated composite porous scaffolds using a combination of PEEK, nano-hydroxyapatite (nHA), and carbon fiber (CF) by the process of fused deposition molding (FDM). The experimental study aimed to assess the impact of varying concentrations of nHA and CF on the biological performance of scaffolds. The incorporation of 10% CF has been shown to enhance the overall mechanical characteristics of composite PEEK scaffolds, including increased tensile strength and improved mechanical strength. Additionally, the addition of 20% nHA resulted in a significant increase in the surface roughness of the scaffolds. The high hydrophilicity of the PEEK composite scaffolds facilitated the in vitro inoculation of MC3T3-E1 cells. The findings of the study demonstrated that the inclusion of 20% nHA and 10% CF in the scaffolds resulted in improved cell attachment and proliferation compared to other scaffolds. This suggests that the incorporation of 20% nHA and 10% CF positively influenced the properties of the scaffolds, potentially facilitating bone regeneration. In vitro biocompatibility experiments showed that PEEK composite scaffolds have good biosafety. The investigation on osteoblast differentiation revealed that the intensity of calcium nodule staining intensified, along with an increase in the expression of osteoblast transcription factors and alkaline phosphatase activities. These findings suggest that scaffolds containing 20% nHA and 10% CF have favorable properties for bone induction. Hence, the integration of porous PEEK composite scaffolds with nHA and CF presents a promising avenue for the restoration of bone defects using materials in the field of bone tissue engineering

Optimizing vestibular neuritis management with modular strategies

ObjectiveThis study proposes a “modular management” approach for vestibular neuritis (VN) to reduce chronicization and improve patient prognosis. The approach involves multi-factor grading and hierarchical intervention and was found to be more effective than traditional treatment strategies.MethodsThis retrospective analysis compared two groups of VN patients from two medical institutions. The intervention group of 52 patients received “modular management,” while the control group of 51 patients did not receive this kind of management. Analyzed the early treatment strategies, 6-month prognosis, and other indicators of the two groups of patients, compared and analyzed their overall prognosis, and identified the risk factors affecting the chronicization.ResultsThe modular management group had lower dizziness severity, better balance, lower anxiety, and higher video head impulse testing (v-HIT) gain after 6 months of onset. Analysis of factors related to persistent postural-perceptual dizziness (PPPD) in patients with VN showed positive correlations between the time from onset to diagnosis and PPPD, and Vertigo Symptom Scale (VSS), Dizziness Handicap Inventory (DHI), anxiety, and depression. Normalized vestibular rehabilitation was negatively correlated with PPPD, while gender, age, and early steroid use had no significant correlation. The multi-factor logistic regression model correctly classified 93.20% of the study subjects with a sensitivity of 87.50% and specificity of 94.90%.ConclusionThe proposed “modular management” scheme for VN is a comprehensive and dynamic approach that includes health education, assessment, rehabilitation, therapy, evaluation, and prevention. It can significantly improve patient prognosis and reduce chronicization by shifting from simple acute treatment to continuous management

Identification of forensically important sarcophagid flies (Diptera: Sarcophagidae) based on COI gene in China

Abstract: Identifing an insect specimen is a crucial step in forensic entomology. As the stages and species of insect discovered on a corpse, such as Calliphoridae and Sarcophagidae, provides evidence for estimation of postmortem interval (PMI). However, morphologically distinguish may on occasion be impossible to the adult flies and nymphs of the same genus. A molecular method used the cytochrome oxidase subunits one (COI) sequence on mitochondrial DNA was established for sarcophagid species identification. In this study, a 272 base pair region of mitochondrial DNA (mtDNA) coding for COI was investigated for identification of the following forensically important sarcophagid flies. The specimens were from four families, including 8 Boerttcherisca Peregrina (Robineau -Desvoidy,1830) specimens of Boettcherisca, 2 Parasarcophaga similis (Meade, 1876) specimens, 4 Parasarcophaga albiceps (Meigen, 1826) and 8 Parasarcophaga dux (Thompson, 1869) specimens from Parasarcophaga. Phylogenetic analysis indicates that this partial COI region successfully identified all samples species to species group. Low levels of variation between some species indicate that sarcophagid flies from more locations should be studied in the future and local database set up are strongly recommended in China

Rab11-FIP1C and Rab14 Direct Plasma Membrane Sorting and Particle Incorporation of the HIV-1 Envelope Glycoprotein Complex

The incorporation of the envelope glycoprotein complex (Env) onto the developing particle is a crucial step in the HIV-1 lifecycle. The long cytoplasmic tail (CT) of Env is required for the incorporation of Env onto HIV particles in T cells and macrophages. Here we identify the Rab11a-FIP1C/RCP protein as an essential cofactor for HIV-1 Env incorporation onto particles in relevant human cells. Depletion of FIP1C reduced Env incorporation in a cytoplasmic tail-dependent manner, and was rescued by replenishment of FIP1C. FIP1C was redistributed out of the endosomal recycling complex to the plasma membrane by wild type Env protein but not by CT-truncated Env. Rab14 was required for HIV-1 Env incorporation, and FIP1C mutants incapable of binding Rab14 failed to rescue Env incorporation. Expression of FIP1C and Rab14 led to an enhancement of Env incorporation, indicating that these trafficking factors are normally limiting for CT-dependent Env incorporation onto particles. These findings support a model for HIV-1 Env incorporation in which specific targeting to the particle assembly microdomain on the plasma membrane is mediated by FIP1C and Rab14. © 2013 Qi et al.Link_to_subscribed_fulltex