Revealing Intramolecular Isotope Effects with Chemical-Bond Precision.

Isotope substitution of a molecule not only changes its vibrational frequencies but also changes its vibrational distributions in real-space. Quantitatively measuring the isotope effects inside a polyatomic molecule requires both energy and spatial resolutions at the single-bond level, which has been a long-lasting challenge in macroscopic techniques. By achieving ångström resolution in tip-enhanced Raman spectroscopy (TERS), we record the corresponding local vibrational modes of pentacene and its fully deuterated form, enabling us to identify and measure the isotope effect of each vibrational mode. The measured frequency ratio νH/νD varies from 1.02 to 1.33 in different vibrational modes, indicating different isotopic contributions of H/D atoms, which can be distinguished from TERS maps in real-space and well described by the potential energy distribution simulations. Our study demonstrates that TERS can serve as a non-destructive and highly sensitive methodology for isotope detection and recognition with chemical-bond precision.

The ultrasound-guided versus standard technique for peripheral intravenous catheter placement by nurses: A systematic review and meta-analysis.

Aim: To comprehensively evaluate the efficacy of Ultrasound-guided technique for peripheral intravenous catheter placement by nurses in their daily practice. Background: Peripheral intravenous catheter insertion is a common clinical procedure in healthcare settings. Ultrasound-guided peripheral intravenous placement has emerged in recent decades and was recognized as particularly useful in some specific patient groups. Methods: Studies that had compared the ultrasound-guided and traditional approaches were eligible for inclusion and further analysis. The primary outcome was the success rate on the first intravenous insertion attempt. The secondary outcomes included the time needed for successful insertion, and the average number of attempts to establish the IV access. We systematically assess all studies using Cochrane Collaboration's Risk of Bias tool and the Newcastle-Ottawa Scale. We calculated the odds ratio and standardized mean difference with 95 % confidence intervals for the outcomes. Data were analyzed and visualized on Review Manager 5.3.4 and Stata 16.0. Results: 23 studies were included (17 randomized controlled trials and six cohort studies) with a population of 2051 patients offered ultrasound-assisted technique and 2479 treated with the conventional approach for comparison. The former approach was associated with a higher success rate on the first attempt in comparison (OR = 2.95, 95 % CI: 1.86, 4.69). This technique also took less time and less acupuncture to patients' skin (SMD = -0.62, 95 % CI: 1.01, -0.23; SMD = -0.55, 95 % CI: 0.92, -0.18). In the sub-group analyses, children were more likely to benefit from ultrasound guided technique. Ultrasound guided technique demonstrated consistent and significant benefits in emergency clinical settings. Hospitals from different geographical locations exhibited similar trends in the three outcomes. Year of publication and study design revealed inconsistent and insignificant outcomes. Conclusions: Ultrasound-guided technique can be a safer, faster, and more effective alternative to the traditional approach for nurses to establish intravenous access across different clinical settings and age groups.

Systemic inflammatory regulators and preeclampsia: a two-sample bidirectional Mendelian randomization study.

Background: Systemic inflammatory regulators have been associated with preeclampsia (PE) during pregnancy; however, there is inconsistent evidence from animal models and observational results. Methods: Using summary data from genome-wide association studies (GWASs), we performed a bidirectional Mendelian randomization (MR) analysis of two samples of systemic inflammatory regulators (n = 8,186) and PE (n = 267,242) individuals of European ancestry. As our primary analysis, we used the random-effects inverse-variance weighted (IVW) approach. Sensitivity and pleiotropy analyses were conducted using the MR-Egger method, weighted median, MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO), and Cochran's Q test. Results: The results indicate that there is a correlation between a higher circulating level of tumor necrosis factor alpha (TNF-α) and interleukin-9 (IL-9) and an increased risk of PE (odds ratio [OR] = 1.32, 95% confidence interval [CI] = 1.09-1.60, p = 0.004 and OR = 1.28, 95% CI: 1.02-1.62, p = 0.033, respectively). Conversely, lower levels of stem cell growth factor beta (SCGF-ß) (OR = 0.89, 95% CI: 0.80-0.99, p = 0.027) and interleukin-5 (IL-5) (OR = 0.80, 95% CI: 0.65-0.98, p = 0.030) are linked to an increased risk of PE. The macrophage migration inhibitory factor (MIF) is the downstream inflammatory regulator of PE, according to reverse magnetic resonance imaging studies. Conclusion: Our study suggests that SCGF-ß, IL-5, IL-9, and TNF-α causally affect the PE risk, while PE is causally associated with MIF. Further studies are needed to validate these biomarkers in managing PE.