Identifying the short-lived intermediates and reaction mechanisms of multi-channel radical cation fragmentation processes remains a current and important challenge to understanding and predicting mass spectra. We find that coherent oscillations in the femtosecond time-dependent yields of several product ions following ultrafast strong-field ionization represent spectroscopic signatures that elucidate their mechanism of formation and identify the intermediate(s) they originate from. Experiments on endo-dicyclopentadiene show that vibrational frequencies from various intermediates are mapped onto their resulting products. Aided by ab initio methods, we identify the vibrational modes of both the cleaved and intact molecular ion intermediates. These results confirm stepwise and concerted fragmentation pathways of the dicyclopentadiene ion. This study highlights the power of tracking the femtosecond dynamics of all product ions simultaneously and sheds further light onto one of the fundamental reaction mechanisms in mass spectrometry, the retro-Diels Alder reaction.
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http://dx.doi.org/10.1038/s42004-024-01176-5 | DOI Listing |
J Gen Fam Med
January 2025
Department of Urology UMass Memorial Health Worcester Massachusetts USA.
Background: Our goal was to identify, and risk stratify primary care patients with microscopic hematuria (MH), describe the diagnostic evaluations they received, and determine whether the evaluations were consistent with the recommendations of the 2020 AUA/SUFU microscopic hematuria guidelines.
Methods: A retrospective review of patients presenting to primary care clinics with a diagnosis of MH was performed. The patient risk category was determined based on the 2020 AUA/SUFU guidelines.
Eur J Neurol
January 2025
Neuromuscular Unit, Neurology Department, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
Background: Charcot-Marie-Tooth (CMT) disease is the most common inherited neuropathy. In this study, we aimed to analyze the genetic spectrum and describe phenotypic features in a large cohort from Türkiye.
Methods: Demographic and clinical findings were recorded.
Cerebellum
January 2025
Clinical and Experimental Neuropsychology Laboratory, Faculty of Psychology, Geneva, Switzerland.
While deficits in episodic memory have been noted following cerebellar damage, there is a lack of research systematically exploring the socio-demographic and cognitive profiles of patients with such impairments. This study aimed to differentiate between chronic-phase cerebellar stroke patients with and without verbal episodic memory deficits, and to determine whether those with deficits exhibit distinct socio-demographic and clinical profiles, thereby identifying potential factors associated with these impairments. Data from 15 cerebellar stroke patients in the CEREBEMO cohort were analyzed, with participants categorized into two groups based on verbal episodic memory performance: deficits (n = 8) and no deficits (n = 7).
View Article and Find Full Text PDFEquine Vet J
January 2025
Department of Veterinary Clinical Sciences, University of Copenhagen, Taastrup, Denmark.
Background: MicroRNAs, a class of small noncoding RNAs, serve as post-transcriptional regulators of gene expression and are present in a stable and quantifiable form in biological fluids. MicroRNAs may influence intra-articular responses and the course of disease, but very little is known about their temporal changes in osteoarthritis.
Objectives: To identify miRNAs and characterise the temporal changes in their abundance in SF from horses with experimentally induced osteoarthritis.
JAMA Netw Open
January 2025
Dow Division of Health Services Research, Department of Urology, University of Michigan, Ann Arbor.
Importance: Active surveillance in men with less aggressive prostate cancer is inconsistently used despite clinical guidelines. Renumeration generally favors treatment over conservative management and may contribute to the variable adoption of active surveillance, which suggests that value-based payment incentives may promote guideline-concordant care.
Objective: To describe the adoption of active surveillance in low-risk prostate cancer, following the initiation of a novel payment incentive sponsored by a commercial payer to support its use.
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