Analgesic effect of non-nutritive sucking in term neonates: A randomized controlled trial.

BACKGROUND: Newborns commonly experience pain due to a variety of reasons. Non-nutritive sucking (NNS) is thought to be an effective non-pharmacological method of pain-relief. However, the significant heterogeneity in some systematic reviews limited the certainty of the findings about NNS. Hence, this study was aimed at evaluating the analgesic effect and safety of NNS in healthy term neonates during the heel prick test, using the Neonatal Pain Agitation and Sedation Scale (N-PASS). METHODS: In this randomized controlled trial, 42 term infants were included: 22 infants in the intervention group (receiving NNS) and 20 infants in the control group (not receiving NNS). In the intervention group, neonates were given a silicone pacifier 120 s before, during, and 120 s after the heel puncture, while neonates in the control group received routine care. Pain-related outcomes were assessed using the N-PASS at 30s, 60s, 90s, and 120s after the heel prick. Any adverse events during the procedure were noted. The Spearman correlation coefficients between the pain scores on the N-PASS and two other scales (NFCS and NIPS) were calculated at all four moments of evaluation. RESULTS: The mean N-PASS pain scores at 30s, 60s, 90s, and 120s after heel prick were significantly lower in the NNS group than in the control group: 4.73 ± 2.78 vs. 7.90 ± 1.52 (p = 0.0002); 3.64 ± 3.06 vs. 5.55 ± 2.95 (p = 0.052); 2.59 ± 3.08 vs. 5.25 ± 3.51 (p = 0.011); and 2.05 ± 2.94 vs. 4.90 ± 3.99 (p = 0.013), respectively. No adverse events were detected in either group. Our findings revealed a strong positive correlation between the pain scores on the N-PASS and two other scales (NFCS and NIPS), which was statistically significant (p < 0.01). CONCLUSIONS: NNS is considered a safe and effective pain-relief method during the heel prick procedure in term neonates, demonstrated using the N-PASS. These findings were correlated with the pain evaluation by NFCS and NIPS.

Quality of flow diagram in systematic review and/or meta-analysis.

Systematic reviews and/or meta-analyses generally provide the best evidence for medical research. Authors are recommended to use flow diagrams to present the review process, allowing for better understanding among readers. However, no studies as of yet have assessed the quality of flow diagrams in systematic review/meta-analyses. Our study aims to evaluate the quality of systematic review/meta-analyses over a period of ten years, by assessing the quality of the flow diagrams, and the correlation to the methodological quality. Two hundred articles of "systematic review" and/or "meta-analysis" from January 2004 to August 2015 were randomly retrieved in Pubmed to be assessed for the flow diagram and methodological qualities. The flow diagrams were evaluated using a 16-grade scale corresponding to the four stages of PRISMA flow diagram. It composes four parts: Identification, Screening, Eligibility and Inclusion. Of the 200 articles screened, 154 articles were included and were assessed with AMSTAR checklist. Among them, 78 articles (50.6%) had the flow diagram. Over ten years, the proportion of papers with flow diagram available had been increasing significantly with regression coefficient beta = 5.649 (p = 0.002). However, the improvement in quality of the flow diagram increased slightly but not significantly (regression coefficient beta = 0.177, p = 0.133). Our analysis showed high variation in the proportion of articles that reported flow diagram components. The lowest proportions were 1% for reporting methods of duplicates removal in screening phase, followed by 6% for manual search in identification phase, 22% for number of studies for each specific/subgroup analysis, 27% for number of articles retrieved from each database, and 31% for number of studies included in qualitative analysis. The flow diagram quality was correlated with the methodological quality with the Pearson's coefficient r = 0.32 (p = 0.0039). Therefore, this review suggests that the reporting quality of flow diagram is less satisfactory, hence not maximizing the potential benefit of the flow diagrams. A guideline with standardized flow diagram is recommended to improve the quality of systematic reviews, and to enable better reader comprehension of the review process.

Modified optical fiber daylighting system with sunlight transportation in free space.

We present the design, optical simulation, and experiment of a modified optical fiber daylighting system (M-OFDS) for indoor lighting. The M-OFDS is comprised of three sub-systems: concentration, collimation, and distribution. The concentration part is formed by coupling a Fresnel lens with a large-core plastic optical fiber. The sunlight collected by the concentration sub-system is propagated in a plastic optical fiber and then collimated by the collimator, which is a combination of a parabolic mirror and a convex lens. The collimated beam of sunlight travels in free space and is guided to the interior by directing flat mirrors, where it is diffused uniformly by a distributor. All parameters of the system are calculated theoretically. Based on the designed system, our simulation results demonstrated a maximum optical efficiency of 71%. The simulation results also showed that sunlight could be delivered to the illumination destination at distance of 30 m. A prototype of the M-OFDS was fabricated, and preliminary experiments were performed outdoors. The simulation results and experimental results confirmed that the M-OFDS was designed effectively. A large-scale system constructed by several M-OFDSs is also proposed. The results showed that the presented optical fiber daylighting system is a strong candidate for an inexpensive and highly efficient application of solar energy in buildings.

Modal loss mechanism of micro-structured VCSELs studied using full vector FDTD method.

Modal properties of vertical cavity surface-emitting lasers (VCSELs) with holey structures are studied using a finite difference time domain (FDTD) method. We investigate loss behavior with respect to the variation of structural parameters, and explain the loss mechanism of VCSELs. We also propose an effective method to estimate the modal loss based on mode profiles obtained using FDTD simulation. Our results could provide an important guideline for optimization of the microstructures of high-power single-mode VCSELs.

Ultralow bending loss fibers with higher-order mode strippers.

We propose and demonstrate bend-insensitive fibers equipped with higher-order mode strippers. The mode stripper is realized by filling a section of air holes with epoxy to attenuate any higher-order modes that are excited at fiber junctions and are confined by the air holes surrounding the core. We found that the higher-order modes are well suppressed with 5 cm-long epoxy columns. An ultralow bending loss of 0.025 dB/turn at a bend diameter of 10 mm, together with single-modeness, is experimentally demonstrated in a bend-insensitive fiber with six air holes 16 µm in diameter.

Bending loss analyses of photonic crystal fibers based on the finite-difference time-domain method.

This is a report on an effective simulation method for the bending loss analyses of photonic crystal fibers. This method is based on the two-dimensional finite-difference time-domain algorithm and a conformal transformation of the refractive index profile. We observed the temporal dynamics of light waves in a bent fiber in a simulation and obtained the bending loss as a function of bend radius and optical wavelength for the commercial photonic crystal fibers. The accuracy of this method was verified by good agreement between the simulation and experimental data.