Detonation Velocity Measurement with Chirped Fiber Bragg Grating

Detonation velocity is an important parameter for explosive, and it is crucial for many fields such as dynamic chemistry burn models, detonation propagation prediction, explosive performance estimation, and so on. Dual-channel detonation velocity measurement method and system are described. The CFBG sensors are pasted both on the surface and in the center of the explosive cylinder. The length of CFBG sensors is measured via the hot-tip probe method. The light intensity reflected from the CFBG sensors attached to the explosive is transformed to voltage, and the voltage–time is then measured with the oscilloscope. According to the five experiments results, the relative standard uncertainty of detonation velocity is below 1%

Novel Fiber-Optic Ring Acoustic Emission Sensor

Acoustic emission technology has been applied to many fields for many years. However, the conventional piezoelectric acoustic emission sensors cannot be used in extreme environments, such as those with heavy electromagnetic interference, high pressure, or strong corrosion. In this paper, a novel fiber-optic ring acoustic emission sensor is proposed. The sensor exhibits high sensitivity, anti-electromagnetic interference, and corrosion resistance. First, the principle of a novel fiber-optic ring sensor is introduced. Different from piezoelectric and other fiber acoustic emission sensors, this novel sensor includes both a sensing skeleton and a sensing fiber. Second, a heterodyne interferometric demodulating method is presented. In addition, a fiber-optic ring sensor acoustic emission system is built based on this method. Finally, fiber-optic ring acoustic emission experiments are performed. The novel fiber-optic ring sensor is glued onto the surface of an aluminum plate. The 150 kHz standard continuous sinusoidal signals and broken lead signals are successfully detected by the novel fiber-optic ring acoustic emission sensor. In addition, comparison to the piezoelectric acoustic emission sensor is performed, which shows the availability and reliability of the novel fiber-optic ring acoustic emission sensor. In the future, this novel fiber-optic ring acoustic emission sensor will provide a new route to acoustic emission detection in harsh environments

Neural substrates of the emotion-word and emotional counting Stroop tasks in healthy and clinical populations: A meta-analysis of functional brain imaging studies

The emotional Stroop task (EST) is among the most influential paradigms used to probe attention-related or cognitive control-related emotional processing in healthy subjects and clinical populations. The neuropsychological mechanism underlying the emotional Stroop effect has attracted extensive and long-lasting attention in both cognitive and clinical psychology and neuroscience; however, a precise characterization of the neural substrates underlying the EST in healthy and clinical populations remains elusive. Here, we implemented a coordinate-based meta-analysis covering functional imaging studies that employed the emotion-word or emotional counting Stroop paradigms to determine the underlying neural networks in healthy subjects and the trans-diagnostic alterations across clinical populations. Forty-six publications were identified that reported relevant contrasts (negative > neutral; positive > neutral) for healthy or clinical populations as well as for hyper- or hypo-activation of patients compared to controls. We demonstrate consistent involvement of the vlPFC and dmPFC in healthy subjects and consistent involvement of the vlPFC in patients. We further identify a trans-diagnostic pattern of hyper-activation in the prefrontal and parietal regions. These findings underscore the critical roles of cognitive control processes in the EST and implicate trans-diagnostic cognitive control deficits. Unlike the current models that emphasize the roles of the amygdala and rACC, our findings implicate novel mechanisms underlying the EST for both healthy and clinical populations

The Use of Unidirectional Barbed Suture for Urethrovesical Anastomosis during Robot-Assisted Radical Prostatectomy: A Systematic Review and Meta-Analysis of Efficacy and Safety.

Unidirectional barbed suture (UBS) has been widely used for surgery in recent years, especially for urethrovesical anastomosis (UVA) during robot-assisted radical prostatectomy (RARP). However, the efficacy and safety comparing it with conventional non-barbed suture (CS) for UVA is still controversial.The objective of this study is to assess the current evidence regarding the efficacy and safety of UBS compared with CS for UVA during RARP.We comprehensively searched PubMed, Embase, The Cochrane Library, SinoMed (Chinese) and other databases on Oct. 9, 2014 to conduct a systematic review and meta-analysis of all randomized controlled trials (RCTs) and other comparative studies evaluating these two types of suture. The outcome measures included anastomosis time operative time, posterior reconstruction (PR) time, postoperative leakage (PL) rate and continence rates at different time points (4-6 weeks, 3 months, 6-12 months) after surgery. Secondary outcomes included estimated blood loss (EBL) and length of catheterization (LOC).Three RCTs and six observational studies including 786 cases were identified. Meta-analysis of extractable data showed that use of UBS could significantly reduce anastomosis time (weighted mean difference [WMD]:-3.98min; 95% confidence interval [CI], -6.02 -1.95; p = 0.0001), operative time (WMD:-10.06min; 95% CI, -15.45--4.67; p = 0.0003) and PR time (WMD:-0.93min; 95% CI, -1.52--0.34; p = 0.002). No significant difference was found in PL rate, EBL, LOC, or continence rates at 4-6 weeks, 3 months and 6-12 months after surgery.Our meta-analysis indicates that UBS appears to be safe and efficient as CS for UVA during RARP with not only shorter anastomosis time, operative time, PR time, but also equivalent PL rate, EBL, LOC, and continence rates at 4-6 weeks, 3 months and 6-12 months after surgery. For the inherent limitations of the eligible studies, future more persuasive RCTs are needed to confirm and update our findings

Forest plot and meta-analysis of posterior reconstruction time.

<p>UBS = unidirectional barbed suture; CS = conventional non-barbed suture; SD = standard deviation; IV = inverse variance method; CI = confidence interval.</p

Forest plot and meta-analysis of operative time.

<p>UBS = unidirectional barbed suture; CS = conventional non-barbed suture; SD = standard deviation; IV = inverse variance method; CI = confidence interval.</p

Forest plot and meta-analysis of anastomosis time.

<p>UBS = unidirectional barbed suture; CS = conventional non-barbed suture; SD = standard deviation; IV = inverse variance method; CI = confidence interval.</p

Forest plot and meta-analysis of postoperative leakage rate.

<p>UBS = unidirectional barbed suture; CS = conventional non-barbed suture; SD = standard deviation; M-H = Mantel-Haenszel method; CI = confidence interval.</p

Forest plot and meta-analysis of length of catheterization.

<p>UBS = unidirectional barbed suture; CS = conventional non-barbed suture; SD = standard deviation; IV = inverse variance method; CI = confidence interval.</p

PRISMA flow diagram of studies identified, included, and excluded.

<p>PRISMA flow diagram of studies identified, included, and excluded.</p