Publications by authors named "Kohei Kawai"
Article Synopsis
- Hypertension is a known risk factor for atrial fibrillation (AF) and strokes, but there is limited research on AF screening in hypertensive patients and its link to blood pressure levels.
- A study involving over 4,000 hypertensive patients aged 60 and older in Japan measured their electrocardiograms (ECG) and blood pressure (BP) at home for three months.
- The study found that 5.8% of participants had undiagnosed AF, with no significant differences in AF detection rates based on different baseline BP categories or the use of antihypertensive medication.
Article Synopsis
- Atrial fibrillation (AF) is categorized by duration into paroxysmal, persistent, and long-standing persistent types, with longer durations increasing the risk of recurrence during catheter ablation treatment.
- The study aims to enhance the diagnosis accuracy of AF duration through a predictive model, utilizing data from 272 patients to train a machine learning algorithm.
- Results showed the model achieved 81.8% accuracy in predicting AF duration, significantly improving cardiologists' diagnostic performance from 63.9% to 71.6% after using the model's insights.
Site-selective nucleophilic ring-opening reactions of 2-arylazetidine-2-carboxylic acid ester-derived tetraalkyl ammonium salts 2 with tetrabutylammonium halides (BuNX) to give tertiary alkyl halides are successfully demonstrated. For example, a nucleophilic ring-opening reaction of 2-(-tolyl) derivative 2a with 1.2 equivalents of tetrabutylammonium fluoride (BuNF) in THF at 60 °C preferentially proceeded at a more substituted carbon atom (2-position) compared to a less-substituted carbon atom (4-position) and afforded -butyl 4-(dimethylamino)-2-fluoro-2-(-tolyl)butanoate 3aa in 71% yield as the corresponding tertiary alkyl fluoride.
View Article and Find Full Text PDFIn order to fully understand the role of volatile organic compounds (VOCs) under natural conditions, an adaptable analytical method was developed as the first step. beta-Ionone, beta-cyclocitral, 2-methyl-1-butanol and 3-methyl-1-butanol were simultaneously analyzed in addition to geosmin and 2-MIB using GC/MS with SPME. The slight modification of a known method allowed the simultaneous detection and quantification of these VOCs.
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