ABSTRACT
Continuous monitoring of arterial blood pressure is clinically important for the diagnosis and management of cardiovascular diseases. Soft electronic devices with skin-like properties show promise in a wide range of applications, including the human-machine interface, the Internet of things, and health monitoring. Here, we report the use of add-on soft electronic interfaces to address the connection challenges between soft electrodes and rigid data acquisition circuitry for bioimpedance monitoring of cardiac signals, including heart rate and cuffless blood pressure. Nanocomposite films in add-on electrodes provide robust electrical and mechanical contact with the skin and the rigid circuitry. We demonstrate bioimpedance sensors composed of add-on electrodes for continuous blood pressure monitoring with high accuracy. Specifically, the bioimpedance collected with add-on nanocomposite electrodes shows a signal-to-noise ratio of 37.0 dB, higher than the ratio of 25.9 dB obtained with standard silver/silver chloride (Ag/AgCl gel) electrodes. Although the sample set is low, the continuously measured systolic and diastolic blood pressure offer accuracy of -2.0 ± 6.3 mmHg and -4.3 ± 3.9 mmHg, respectively, confirming the grade A performance based on the IEEE standard. These results show promise in bioimpedance measurements with add-on soft electrodes for cuffless blood pressure monitoring.
ABSTRACT
Glycosyl cations are universally accepted key ionic intermediates in the mechanism of glycosylation, the reaction that covalently links carbohydrates to other molecules. These ions have remained hypothetical species so far because of their extremely short life in organic media as a consequence of their very high reactivity. Here, we report the use of liquid hydrofluoric acid-antimony pentafluoride (HF/SbF5) superacid to generate and stabilize the glycosyl cations derived from peracetylated 2-deoxy and 2-bromoglucopyranose in a condensed phase. Their persistence in this superacid medium allows their three-dimensional structure to be studied by NMR, aided by complementary computations. Their deuteration further confirms the impact of the structure of the glycosyl cation on the stereochemical outcome of its trapping.
Subject(s)
Biomimetic Materials/chemistry , Cations/chemistry , Hydrofluoric Acid/chemistry , Glycosylation , Molecular StructureABSTRACT
La presencia de gas en el sistema venoso hepatoportal es una entidad muy infrecuente que se asocia a cuadros abdominales catastróficos, con una mortalidad del 75 por ciento. Se origina por la presencia de gérmenes productores de gas y/o comunicación directa del gas intraluminal con el espacio portal en casos de lesión mucosa -asociada o no a necrosis intestinal- u obstrucción intestinal. El tratamiento ha de ser combinado e intensivo, con reanimación, antibioterapia y cirugía. Se presenta un cuadro secundario a una etiología excepcionalmente citada, como es la diverticulitis aguda perforada, que inicialmente respondió al tratamiento agresivo médico y quirúrgico, aunque la evolución final fue el fallecimiento del paciente (AU)
