Cantilever-Enhanced Fiber-Optic Photoacoustic Spectrophone for Low-Pressure Gas Detection.

A cantilever-enhanced fiber-optic photoacoustic (PA) spectrophone is reported for trace gas detection at a low-pressure environment. A cantilever-based fiber-optic Fabry-Perot (F-P) interferometer (FPI) is utilized for simultaneous measurement of air pressure and PA pressure. Since the cantilever resonance frequency follows air pressure linearly, the fundamental frequency intensity modulation (1-IM) technique is applied to scan the frequency response of the solid PA signal from tube wall absorption for tracking the cantilever resonance frequency in real time.

Risk factors for vasovagal reactions in blood donors: A systematic review and meta-analysis.

Background: While blood donation is generally safe, some donors experience vasovagal reactions (VVRs) that may lead to injury and reduce likelihood of future donation. Several risk factors for VVRs have been identified, but the consistency, magnitude, and validity of their associations have not been systematically evaluated. Therefore, this systematic review and meta-analysis synthesized evidence for VVR risk factors.

Trends in population attributable fraction of modifiable risk factors for cardiovascular diseases across three decades.

Aims: To evaluate temporal trends, across three decades, in the population attributable fractions (PAFs) of modifiable risk factors for 5-year risk of cardiovascular diseases (CVDs).

Methods And Results: Within population-based Rotterdam Study, we defined three time groups of individuals without established CVD at 'baseline' with a mean age of 70 years, and followed for five years: Epoch 1990s (1989-93, n = 6195), Epoch 2000s (1997-2001, n = 5572), and Epoch 2010s (2009-14, n = 5135). The prevalence of risk factors and related relative risks were combined to quantify PAFs.

Pressure-Compensated Fiber-Optic Photoacoustic Sensors for Trace SO Analysis in Gas Insulation Equipment.

A high-sensitivity fiber-optic photoacoustic sensor with pressure compensation is proposed to analyze the decomposition component SO in high-pressure gas insulation equipment. The multiple influence mechanism of pressure on photoacoustic excitation and cantilever detection has been theoretically analyzed and verified. In the high-pressure environment, the excited photoacoustic signal is enhanced, which compensates for the loss of sensitivity of the cantilever.

Fiber-Optic Photoacoustic Gas Microsensor Dual Enhanced by Helmholtz Resonator and Interferometric Cantilever.

A high-sensitivity fiber-optic photoacoustic (PA) gas microsensor is demonstrated with dual enhancement based on acoustics and detection. Due to the characteristic of small size, a Helmholtz resonator is integrated into a miniature PA sensor. The acoustically amplified PA signal is detected by a high-sensitivity fiber Fabry-Perot (F-P) interferometric cantilever.

Dense Multibutterfly Spots-Enhanced Miniaturized Optical Fiber Photoacoustic Gas Sensor.

A miniaturized optical fiber photoacoustic gas sensor enhanced by dense multibutterfly spots is reported for the first time. The principle of space light transmission of neglecting paraxial approximation is theoretically analyzed for designing a dense multibutterfly spots-based miniature multipass cell. In a multipass photoacoustic tube with a diameter of 16 mm, the light beam is reflected about a hundred times.

Fiber-Optic Photoacoustic CO Sensor for Gas Insulation Equipment Monitoring Based on Cantilever Differential Lock-In Amplification and Optical Excitation Enhancement.

A fiber-optic photoacoustic CO sensor for gas insulation equipment is proposed, which relies on F-P interferometric cantilever-based differential lock-in amplification and optical multipass excitation enhancement. The sensor has excellent characteristics of high sensitivity, antielectromagnetic interference, fast response, and long-distance detection. The photoacoustic pressure waves in the two resonators of the differential photoacoustic cell (DPAC) are simultaneously detected by two fiber-optic interferometric cantilevers and processed differentially; thereby, the gas flow noise is effectively suppressed.

Rapid Photoacoustic Exhaust Gas Analyzer for Simultaneous Measurement of Nitrogen Dioxide and Sulfur Dioxide.

A rapid photoacoustic (PA) exhaust gas analyzer is presented for simultaneous measurements of nitrogen dioxide (NO) and sulfur dioxide (SO). A laser diode (LD) emitting at 450 nm and a light-emitting diode (LED) with a peak wavelength of 275 nm operated simultaneously, producing PA signals of NO and SO, respectively. The LD and LED were modulated at different frequencies of 2568 and 2570 Hz, and their emission light beams were transmitted through two resonant tubes in a differential PA cell (DPAC), respectively.

Differential Cantilever Enhanced Fiber-Optic Photoacoustic Sensor for Diffusion Gas Detection.

Aiming at the problem of the fiber-optic photoacoustic (PA) sensor being easily disturbed by external vibration and noise, a differential cantilever enhanced fiber-optic PA sensor is proposed for diffusion gas detection. The sensor comprises two PA tubes with the same structure and a pair of differential interferometric cantilevers. The two PA tubes are symmetrically distributed.

High-Precision Multipass Fiber-Optic Photoacoustic Gas Analyzer Based on 2/1 Wavelength Modulation Spectroscopy.

A self-calibration fiber-optic photoacoustic (PA) gas analyzer based on 2/1 wavelength modulation spectroscopy (WMS) is proposed, which utilizes gas and solid multipass absorption enhancement. The laser light is incident obliquely on the cell wall, and one end of the cell is equipped with a highly reflective mirror. The gas analyzer takes full advantage of the miniature multipass PA cell, which enhances the absorption of gas and solid simultaneously.

Ultrahigh-speed phase demodulation of a Fabry-Perot sensor based on fiber array parallel spectral detection.

An ultrahigh-speed phase demodulation system was designed for the Fabry-Perot (F-P) interferometric sensor based on fiber array parallel spectral detection. A high-power amplified spontaneous emission (ASE) source served as the broadband detection light. The spectrum generated by the dispersion of the F-P interference light through an arrayed waveguide grating (AWG) was incident into the fiber array and was detected in parallel by 48 photodiodes.

Ultrahigh Sensitive Trace Gas Sensing System with Dual Fiber-Optic Cantilever Multiplexing-Based Differential Photoacoustic Detection.

An ultrahigh sensitive trace gas sensing system was presented with dual cantilever-based differential photoacoustic detection. By combining the double enhancement of multipass absorption and optical differential detection, the gas detection sensitivity was significantly improved. The dual-channel synchronous photoacoustic detection was realized by fiber-optic Fabry-Perot interference spectrum multiplexing.

High-Precision Photoacoustic Nitrogen Dioxide Gas Analyzer for Fast Dynamic Measurement.

A high-precision photoacoustic (PA) gas analyzer for fast dynamic measurement of ambient nitrogen dioxide (NO) was developed. The PA analyzer used a differential PA cell combined with two mufflers to achieve rapid gas flow gas detection. A high-power laser diode (LD) with a center wavelength of 450 nm was used as the PA signal excitation source.

Integrated near-infrared fiber-optic photoacoustic sensing demodulator for ultra-high sensitivity gas detection.

An integrated near-infrared fiber-optic photoacoustic sensing demodulator was established for ultra-high sensitivity gas detection. The demodulator has capacities of interference spectrum acquisition and calculation, laser modulation control as well as digital lock-in amplification. FPGA was utilized to realize all the control and signal processing functions, which immensely improved the integration and stability of the system.

Fiber-Optic Photoacoustic Gas Sensor with Multiplexed Fabry-Pérot Interferometric Cantilevers.

A fiber-optic photoacoustic (PA) gas sensor with multiplexed Fabry-Pérot (F-P) interferometric cantilevers is demonstrated. A compact cylindrical nonresonant PA tube with a volume of only 0.45 mL is designed.

Excess Deaths of Gastrointestinal, Liver, and Pancreatic Diseases During the COVID-19 Pandemic in the United States.

To evaluate excess deaths of gastrointestinal, liver, and pancreatic diseases in the United States during the COVID-19 pandemic. We retrieved weekly death counts from National Vital Statistics System and fitted them with a quasi-Poisson regression model. Cause-specific excess deaths were calculated by the difference between observed and expected deaths with adjustment for temporal trend and seasonality.

Female Reproductive Factors and Risk of New-Onset Heart Failure: Findings From UK Biobank.

Background: A comprehensive evaluation of woman-specific risk factors in relation to incident heart failure (HF) is limited.

Objectives: This study sought to investigate the association of multiple female reproductive factors with the risk of HF.

Methods: Between 2007 and 2010, 229,026 women (mean age: 56.

Latent class analysis-based subgroups and response to corticosteroids in hospitalised community-acquired pneumonia patients: a validation study.

https://bit.ly/3O5eaxz.

Arthroscopic versus Open Distal Hemitrapeziectomy without Interposition: 2-Year Results of a Randomized Controlled Trial.

Background: Distal hemitrapeziectomy is suggested as an alternative for total trapeziectomy for carpometacarpal thumb joint osteoarthritis, when the scaphotrapeziotrapezoidal joint is unaffected. This can be performed as an arthroscopic or open procedure, with suggested advantages for the less invasive arthroscopic technique. To determine which technique has better outcome on subjective and objective measures, the authors performed a prospective, randomized, controlled trial.

Sample size calculation for clinical trials analyzed with the meta-analytic-predictive approach.

The meta-analytic-predictive (MAP) approach is a Bayesian method to incorporate historical controls in new trials that aims to increase the statistical power and reduce the required sample size. Here we investigate how to calculate the sample size of the new trial when historical data is available, and the MAP approach is used in the analysis. In previous applications of the MAP approach, the prior effective sample size (ESS) acted as a metric to quantify the number of subjects the historical information is worth.

Serum IFNα2 levels are associated with disease activity and outperform IFN-I gene signature in a longitudinal childhood-onset SLE cohort.

Objective: To study the association of serum IFNα2 levels measured by ultrasensitive single-molecule array (Simoa) and the IFN-I gene signature (IGS) with disease activity and determine whether these assays can mark disease activity states in a longitudinal cohort of childhood-onset SLE (cSLE) patients.

Methods: Serum IFNα2 levels were measured in 338 samples from 48 cSLE patients and 67 healthy controls using an IFNα Simoa assay. Five-gene IGS was measured by RT-PCR in paired whole blood samples.

Efficacy and safety of switching from intravenous to oral antibiotics (amoxicillin-clavulanic acid) versus a full course of intravenous antibiotics in neonates with probable bacterial infection (RAIN): a multicentre, randomised, open-label, non-inferiority trial.

Background: Switching from intravenous antibiotic therapy to oral antibiotic therapy among neonates is not yet practised in high-income settings due to uncertainties about exposure and safety. We aimed to assess the efficacy and safety of early intravenous-to-oral antibiotic switch therapy compared with a full course of intravenous antibiotics among neonates with probable bacterial infection.

Methods: In this multicentre, randomised, open-label, non-inferiority trial, patients were recruited at 17 hospitals in the Netherlands.

Incorporating historical control information in ANCOVA models using the meta-analytic-predictive approach.

The meta-analytic-predictive (MAP) approach is a Bayesian meta-analytic method to synthesize and incorporate information from historical controls in the analysis of a new trial. Classically, only a single parameter, typically the intercept or rate, is assumed to vary across studies, which may not be realistic in more complex models. Analysis of covariance (ANCOVA) is often used to analyze trials with a pretest-posttest design, where both the intercept and the baseline effect (coefficient of the outcome at baseline) affect the estimated treatment effect.