First-principles study of coadsorption of Cu2+ and Cl− ions on the Cu (110) surface

Motivated by the importance of Cl⁻ in the industrial electrolytic Cu plating process, we study the coadsorption of Cl⁻ and Cu²⁺ on the Cu (110) surface using first-principles density functional theory (DFT) calculations. We treat the solvent implicitly by solving the linearized Poisson–Boltzmann equation and evaluate the electrochemical potential and energetics of ions with the computational hydrogen electrode approach. We find that Cl⁻ alone is hardly adsorbed at sufficiently negative electrochemical potentials μ_Cl but stable phases with half and full Cl⁻ coverage was observed as μ_Cl is made more positive. For Cl⁻ and Cu²⁺ coadsorption, we identified five stable phases for electrode biases between −2V < U_SHE < 2V, with two being Cl⁻ adsorption phases, two being Cl⁻ + Cu²⁺ coadsorption phases and one being a pure Cu²⁺ adsorption phase. In general, the free energy of adsorption for the most stable phases at larger |U_SHE| are dominated by the energy required to move electrons between the system and the Fermi level of the electrode, while that at smaller |U_SHE| are largely dictated by the binding strength between Cl⁻ and Cu²⁺ adsorbates on the Cu (110) substrate. In addition, by studying the free energy of adsorption of Cu²⁺ onto pristine and Cl⁻ covered Cu (110), we conclude that the introduction of Cl⁻ ion does not improve the energetics of Cu²⁺ adsorption onto Cu (110).

Free energy of adsorption for the most stable phases predicted by DFT calculations as a function of electrode potential.     

Impact of the COVID-19 pandemic on hyperacute stroke treatment: experience from a comprehensive stroke centre in Singapore

The Coronavirus disease 2019 (COVID-19) pandemic is rapidly evolving and affecting healthcare systems across the world. Singapore has escalated its alert level to Disease Outbreak Response System Condition (DORSCON) Orange, signifying severe disease with community spread. We aimed to study the overall volume of AIS cases and the delivery of hyperacute stroke services during DORSCON Orange. This was a single-centre, observational cohort study performed at a comprehensive stroke centre responsible for AIS cases in the western region of Singapore, as well as providing care for COVID-19 patients. All AIS patients reviewed as an acute stroke activation in the Emergency Department (ED) from November 2019 to April 2020 were included. System processes timings, treatment and clinical outcome variables were collected. We studied 350 AIS activation patients admitted through the ED, 206 (58.9%) pre- and 144 during DORSCON Orange. Across the study period, number of stroke activations showed significant decline (p?=?0.004, 95% CI 6.513 to???2.287), as the number of COVID-19 cases increased exponentially, whilst proportion of activations receiving acute recanalization therapy remained stable (p?=?0.519, 95% CI???1.605 to 2.702). Amongst AIS patients that received acute recanalization therapy, early neurological outcomes in terms of change in median NIHSS at 24 h (-4 versus -4, p?=?0.685) were largely similar between the pre- and during DORSCON orange periods. The number of stroke activations decreased while the proportion receiving acute recanalization therapy remained stable in the current COVID-19 pandemic in Singapore.

     

Clinics in diagnostic imaging (152). Right lower lobe segmental pulmonary embolus.

A 56-year-old man presented to the Accident and Emergency Department with pleuritic chest pain of sudden onset. He gave a history of short-distance air travel ten days earlier. Chest radiograph showed a peripheral-based opacity in the right lower zone, which was not seen in a previous study done three months ago, suggestive of Hampton’s hump. The D-dimer level was raised. Computed tomography pulmonary angiography confirmed the diagnosis of pulmonary embolism in a right lower lobe segmental branch, with adjacent collapsed lung, consistent with lung infarction. The patient was started on heparin injection with significant relief of his symptoms. The clinical and imaging features of pulmonary embolism are described, with emphasis on the historical radiographic signs and the current dual-energy computed tomography innovations.     

Health‐related quality of life in early Parkinson's disease: The impact of nonmotor symptoms

Nonmotor symptoms (NMS) are common in patients with established Parkinson's disease (PD) and have a major impact upon quality of life. We investigated the significance of NMS in relation to health‐related quality of life (HRQoL) in patients with newly diagnosed PD. Patients and healthy controls were recruited as part of the Incidence of Cognitive Impairment in Cohorts with Longitudinal Evaluation in Parkinson's Disease Study. Prevalence of NMS was determined with the Non‐Motor Symptom Questionnaire. HRQoL was recorded with the 39‐item Parkinson's Disease Quality of Life Questionnaire (PDQ‐39). Further assessments included measures of motor disability, depression, sleep, and cognition. One hundred and fifty‐eight patients with newly diagnosed PD and 99 controls participated in this cross‐sectional study. Patients reported greater numbers of NMS than controls (mean 8.3 ± 4.3 versus 2.8 ± 2.5 symptoms; P < 0.001). Patients reported lowest HRQoL in the domains assessing bodily discomfort, mobility, and activities of daily living. Motor and nonmotor symptoms impacted negatively upon HRQoL scores. Patients with the postural instability and gait difficulty motor subtype reported worse HRQoL, compared with those with tremor‐dominant disease. Depression (P < 0.001), incomplete bowel emptying (P < 0.001), anxiety (P < 0.001), impaired concentration (P < 0.001), memory complaints (P < 0.001), and insomnia (P = 0.001) had the greatest negative impact upon HRQoL. NMS are common in patients with early PD and represent a significant cause of poorer health‐related quality of life. Cognitive, neuropsychiatric, and sleep disturbances are particularly associated with reduced well‐being. Screening and management of these symptoms should be prioritized at the time of diagnosis. © 2013 International Parkinson and Movement Disorder Society     

Cholecystectomy in English Children: Evidence of an Epidemic (1997–2012)

Background/Purpose

The purpose of this study was to calculate the incidence of cholecystectomy among children aged ≤ 16 in England between 1997 and 2012 and to assess trends in risk factors.

Methods

A nationwide retrospective cohort study using the Hospital Episode Statistics Database for episodes of cholecystectomy in children aged ≤ 16 was performed. Age and sex-specific annual incidence rates were derived using Office of National Statistics mid-year population estimates. Trends in the observed case mix were tested using univariable linear regression.

Results

2808 paediatric cholecystectomies were identified. The incidence of cholecystectomy increased from 0.78/100,000 to 2.7/100,000 (P < 0.0001). Sex-specific incidences increased from 1.1 to 4.36/100,000 (P < 0.0001) among girls and from 0.48 to 1.13/100,000 (P < 0.0001) among boys. There were significant changes in case mix, with an increasing proportion of female cases (69% to 79%, P = 0.02), an increase in cases of white ethnicity (48% to 77%, P < 0.0001), but only a modest increase in those with a diagnosis of sickle cell anaemia (4% to 6%, P = 0.02), and no significant increase in other haemolytic anaemias.

Conclusions

There has been a three-fold increase in the incidence of paediatric cholecystectomy in England since 1997, with a particular rise among white females. Although data on BMI were not available, the observed effect may be a consequence of increasing levels of teenage obesity.