A parallel line probe for spatially selective electrochemical NMR spectroscopy.

In situ NMR is a valuable tool for studying electrochemical devices, including redox flow batteries and electrocatalytic reactors, capable of detecting reaction intermediates, metastable states, time evolution of processes or monitoring stability as a function of electrochemical conditions. Here we report a parallel line detector for spatially selective in situ electrochemical NMR spectroscopy. The detector consists of 17 copper wires and is doubly tuned to 1H/19F and X nuclei ranging from 63Cu (106.1 MHz) to 7Li (155.5 MHz). The flat geometry of the parallel line detector allows its insertion into a high electrode surface-to-volume electrochemical flow reactor, enabling a detector-in-a-reactor design. This integrated device is named "eReactor NMR probe". Combined with B1-selective pulse sequences, selective detection of the nuclei at the electrode-electrolyte interface, that is within a distance of 800 µm from the electrode surface, has been achieved. The selective detection of 7Li and 19F nuclei is demonstrated using two electrolytes, LiCl and LiBF4 solutions, respectively. A good B1 homogeneity with an 810° to 90° pulse intensity ratio of 68-72 % was achieved. Using electrochemical plating of lithium metal as a model reaction, we further demonstrated the operando functionality of the probe. The new eReactor NMR probe offers a general method for studying flow electrochemistry, and we envision applications in a wide range of environmentally relevant energy systems, for example, Li metal batteries, electrochemical ammonia synthesis, carbon dioxide capture and reduction, redox flow batteries, fuel cells, water desalination, lignin oxidation etc.

Marked underdiagnosis and undertreatment of hypertension and hypercholesterolaemia in rheumatoid arthritis.

OBJECTIVE: To investigate the prevalence of underdiagnosis and undertreatment of traditional cardiovascular risk factors in RA patients. METHODS: RA patients ⩽70 years of age without cardiovascular disease (CVD) or diabetes mellitus were included. Systolic blood pressure and a fasting lipid profile were measured. The 10-year CVD risk was estimated using the Dutch Cardiovascular Risk Management (CVRM) guideline and EULAR modifications of the Systemic Coronary Risk Evaluation tables. RESULTS: A total of 327 patients were included (female gender: 68%). The mean age was 53 (11) years [mean (s.d.)]. The median disease duration was 7 years (inter quartile range: 2-14 years). According to the CVRM guideline, 52% of the patients had a CVD risk ⩾20% and according to the EULAR guidelines, 18% of the patients had a CVD risk ≥ 20%. Low-density lipoprotein cholesterol (LDL-C) >2.5 mmol/l was found in >80% of the patients with a CVD risk ⩾10% as estimated by both the CVRM and EULAR guidelines, and 32-42% of the patients with a CVD risk ⩾10% had a systolic blood pressure >140 mmHg, depending on the risk model used. Statins were used in 6% and antihypertensives in 23-25%, and 50-86% of these patients did not reach the recommended treatment targets. CONCLUSION: Regardless of the adapted risk assessment model used, untreated hypertension and hypercholesterolaemia were frequently found in RA patients with increased CVD risk. Treatment of these cardiovascular risk factors deserves more attention in RA. TRIAL REGISTRATION: The Dutch Trial Register, www.trialregister.nl, NTR3873.

Association of Cardiovascular Risk Factors with Carotid Intima Media Thickness in Patients with Rheumatoid Arthritis with Low Disease Activity Compared to Controls: A Cross-Sectional Study.

OBJECTIVES: Rheumatoid arthritis (RA) has been identified as an independent cardiovascular risk factor. The importance of risk factors such as hypertension and hyperlipidemia in the generation of atherosclerosis in RA patients is unclear. This study analyzed clinical parameters associated with carotid intima media thickness (cIMT) in patients with RA. METHODS: Subjects with RA and healthy controls without RA, both without known cardiovascular disease, were included. Participants underwent a standard physical examination and laboratory measurements including a lipid profile. cIMT was measured semi-automatically by ultrasound. RESULTS: In total 243 RA patients and 117 controls were included. The median RA disease duration was 7 years (IQR 2-14 years). The median DAS28 was 2.4 (IQR 1.6-3.2) and 114 (50.4%) of the RA patients were in remission. The presence of RA and cIMT were not associated (univariate analysis). Multivariable regression analysis showed that cIMT in RA patients was associated with age (B = 0.006, P<0.001) and systolic blood pressure (B = 0.003, P = 0.003). In controls, cIMT was associated with age (B = 0.006, P<0.001) and smoking (B = 0.097, P = 0.001). CONCLUSION: cIMT values were similar between RA patients and controls. Hypertension was strongly associated with cIMT in RA patients. After adjustment, no association between cIMT and specific RA disease characteristics was found in this well treated RA cohort.

A microfluidic high-resolution NMR flow probe.

A microfluidic high-resolution NMR flow probe based on a novel stripline detector chip is demonstrated. This tool is invaluable for the in situ monitoring of reactions performed in microreactors. As an example, the acetylation of benzyl alcohol with acetyl chloride was monitored. Because of the uncompromised (sub-Hz) resolution, this probe holds great promise for metabolomics studies, as shown by an analysis of 600 nL of human cerebrospinal fluid.