A proof-of-concept for the electrochemical detection of single Escherichia coli bacteria decorated with silver nanoparticles is reported. Impacts of bacteria with an electrode - held at a suitably oxidizing potential - lead to an accompanying burst of current with each collision event. The frequency of impacts scales with the concentration of bacteria and the charge indicates the extent of decoration.

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Aim We examined the impact of the COVID‐19 pandemic on how many children were admitted to Israel's largest tertiary paediatric hospital and why they were admitted. Methods Israel declared COVID‐19 a national emergency on 19 March 2020. This study examined daily hospital admissions to our three general paediatric wards during the COVID‐19 lockdown period from 20 March to 18 April 2020. These 258 admissions were compared with the 4217 admissions from the period immediately before this, 1 February to 19 March 2020, plus 1 February to 18 April in 2018 and 2019. We also compared why patients were admitted during the study period, and any pre‐existing conditions, with 638 children hospitalised during the same period in 2019. Results The mean number of daily hospitalisations during the COVID‐19 lockdown period was 8.6, which was 59% lower than the 20.9 recorded during the other three periods before COVID‐19. There was a significant decrease in the number of patients admitted with infectious (74%) and non‐infectious (44%) aetiologies from 2019 to 2020, and these occurred among patients with (58%), and without (55%), pre‐existing medical conditions. Conclusion The Israeli COVID‐19 lockdown had a dramatic effect on admissions to the paediatric wards of a tertiary hospital.

BackgroundChronic obstructive pulmonary disease exacerbations (COPDEs) are associated with increased morbidity and mortality. Cell-free DNA (cfDNA) is a novel biomarker associated with clinical outcomes in several disease states but has not been studied in COPD. The objectives of this study were to assess cfDNA levels during a COPDE, to evaluate the association of cfDNA with clinical parameters and to explore the prognostic implications of cfDNA levels on long-term survival.MethodsThis was an observational study that assessed cfDNA levels in patients admitted to hospital for a COPDE. Plasma cfDNA levels of COPDE patients were compared to those of matched stable COPD patients and healthy controls. Multivariable and Cox regression analyses were used to assess the association of cfDNA levels with blood gas parameters and long-term survival.ResultsA total of 62 patients (46 males, forced expiratory volume in 1 second [FEV1] 38%±13%) were included. The median cfDNA levels on admission for COPDE patients was 1,634 ng/mL (interquartile range [IQR] 1,016–2,319) compared to 781 ng/mL (IQR 523–855) for stable COPD patients, matched for age and disease severity, and 352 ng/mL (IQR 209–636) for healthy controls (P<0.0001, for both comparisons). cfDNA was correlated with partial arterial pressure of carbon dioxide (PaCO2, r=0.35) and pH (r=−0.35), P=0.01 for both comparisons. In a multivariable analysis, PaCO2 was the only independent predictor of cfDNA. Using a cfDNA level of 1,924 ng/mL (threshold for abnormal PaCO2), those with high levels had a trend for increased 5-year mortality risk adjusted for age, sex and FEV1% (hazard ratio 1.92, 95% confidence interval 0.93–3.95, P=0.08).ConclusionPlasma cfDNA might offer a novel technique to identify COPD patients at increased risk of poor outcomes, but the prognostic utility of this measurement requires further study.