Overtone Excitation of Nitrogen Molecules via Stimulated Raman Pumping.

Nitrogen bond activation is a pivotal process in chemistry, with bond excitation being fundamental to understanding the underlying mechanisms, making the preparation of molecules in specific quantum states crucial. Here we report the first overtone excitation of the N molecule from XΣ( = 0, = 0, 1, and 2) to XΣ( = 2, = 0, 1, 2, and 3) using the stimulated Raman pumping (SRP) method in a pulsed molecular beam. N was detected using 2+1 resonance-enhanced multiphoton ionization through the a″Σ state.

Preparation of High Vibrational States in the Entire Molecular Beam.

Preparing highly excited molecules is of great interest in chemistry, but it has long been a challenge due to the high laser power required within the narrow line width to excite a weak transition. We present a cavity-enhanced infrared excitation scheme using a milliwatt laser. As a demonstration, about 35% of CO molecules in a ground-state rotational level were excited to the highly excited = 3 state in the entire pulsed supersonic beam, as confirmed by the depletion of molecules in the ground state.

Corrigendum: Association between weight-adjusted waist index and kidney stones: a propensity score matching study.

[This corrects the article DOI: 10.3389/fendo.2024.

Association between weight-adjusted waist index and kidney stones: a propensity score matching study.

Objective: This study aimed to investigate the association between weight-adjusted waist index (WWI), a novel adiposity index, and kidney stone (KS).

Methods: Data were obtained from the National Health and Nutrition Examination Survey 2007-2018. According to the history of KS, participants were divided into the non-stone group and the stone group.

Enhanced Total Vibrational Excitation Yield in a Slow Narrow-Pulsed Hydrogen Molecular Beam.

High-efficiency excitation of a molecular beam is critical for investigating state-selected chemistry. However, achieving vibrational excitation of the entire beam for Raman-active molecules such as H proves extremely challenging, primarily because laser pulses are much shorter than the molecular beam. In this study, we achieve a total excitation efficiency of over 20% by employing stimulated Raman pumping (SRP) in a slow, narrow-pulsed molecular beam.

Stereodynamical control of the H + HD → H + D reaction through HD reagent alignment.

Prealigning nonpolar reacting molecules leads to large stereodynamical effects because of their weak steering interaction en route to the reaction barrier. However, experimental limitations in preparing aligned molecules efficiently have hindered the investigation of steric effects in bimolecular reactions involving hydrogen. Here, we report a high-resolution crossed-beam study of the reaction H + HD( = 1, = 2) → H(', ') + D at collision energies of 0.

Suctioning Versus Traditional Access Sheath in Mini-Percutaneous Nephrolithotomy: A Systematic Review and Meta-analysis.

Purpose: The suctioning access sheath (SAS) is a novel access sheath connected to a negative pressure suction device and absorbs fragments. Some comparative studies have reported SAS with a higher stone-free rate and lower operative time. However, no higher-level evidence was published to support SAS.

Safety of transrectal ultrasound-guided prostate biopsy in patients receiving aspirin: An update meta-analysis including 3373 patients.

Background: The management of aspirin before transrectal prostate puncture-guided biopsy continues to be controversial. The conclusions in newly published studies differ from the published guideline. Therefore, an updated meta-analysis was performed to assess the safety of continuing to take aspirin when undergoing a transrectal ultrasound-guided prostate biopsy (TRUS-PB).

Plasmon-enhanced coherent anti-stokes Raman scattering vs plasmon-enhanced stimulated Raman scattering: Comparison of line shape and enhancement factor.

Plasmon-enhanced coherent Raman scattering microscopy has reached single-molecule detection sensitivity. Due to the different driven fields, there are significant differences between a coherent Raman scattering process and its plasmon-enhanced derivative. The commonly accepted line shapes for coherent anti-Stokes Raman scattering and stimulated Raman scattering do not hold for the plasmon-enhanced condition.

Vibrational overtone excitation of D in a molecular beam with a high-energy, narrow-bandwidth, nanosecond optical parametric oscillator/amplifier.

We have built a high-energy, narrow-bandwidth, nanosecond light source for efficient preparation of vibrationally excited molecules in a molecular beam. It consists of an injection-seeded optical parametric oscillator and two optical parametric amplifiers. Pumped by the second harmonic of a commercial injection-seeded Nd:YAG laser, it can generate pulse energies up to 377 mJ at 655 nm with a bandwidth smaller than 200 MHz.

Quantum interference in H + HD → H + D between direct abstraction and roaming insertion pathways.

Understanding quantum interferences is essential to the study of chemical reaction dynamics. Here, we provide an interesting case of quantum interference between two topologically distinct pathways in the H + HD → H + D reaction in the collision energy range between 1.94 and 2.

Experimental and Theoretical Study of the Vibrationally Excited Reaction Cl + D ( = 1, = 0) → DCl + D.

Vibrationally excited reaction of Cl + D ( = 1, = 0) → DCl + D was investigated by a high-resolution crossed beam experiment, with D molecules in the vibrationally excited state prepared by the scheme of stimulated Raman pumping. Differential cross sections (DCSs) were obtained at three collision energies of 4.03, 4.

Effect of Reagent Vibrational Excitation on the Dynamics of F + H2(v = 1, j = 0) → HF(v', j') + H Reaction.

The reaction of fluorine atom with vibrationally excited H2 at v = 1 has been studied using a high resolution crossed molecular beam apparatus at collision energies of 0.52 and 0.90 kcal/mol.