Ab initio and density functional theoretical design and screening of model crown ether based ligand (host) for extraction of lithium metal ion (guest): effect of donor and electronic induction.

The structures, energetic and thermodynamic parameters of model crown ethers with different donor, cavity and electron donating/ withdrawing functional group have been determined with ab initio MP2 and density functional theory in gas and solvent phase. The calculated values of binding energy/ enthalpy for lithium ion complexation are marginally higher for hard donor based aza and oxa crown compared to soft donor based thia and phospha crown. The calculated values of binding enthalpy for lithium metal ion with 12C4 at MP2 level of theory is in good agreement with the available experimental result.

Socioeconomic status and transient ischaemic attack/stroke: a prospective observational study.

Background: Lower socioeconomic status (SES) is associated with an increased risk of stroke but the mechanisms are unclear. We aimed to determine whether low-SES stroke/transient ischaemic attack (TIA) patients have a greater burden of vascular risk factors/co-morbidity and reduced health care access.

Methods: We prospectively studied 467 consecutive stroke and TIA patients from 3 Scottish hospitals (outpatients and inpatients) during 2007/2008.

DFT modeling on the suitable crown ether architecture for complexation with Cs⁺ and Sr²⁺ metal ions.

Crown ether architectures were explored for the inclusion of Cs(+) and Sr(2+) ions within nano-cavity of macrocyclic crown ethers using density functional theory (DFT) modeling. The modeling was undertaken to gain insight into the mechanism of the complexation of Cs(+) and Sr(2+) ion with this ligand experimentally. The selectivity of Cs(+) and Sr(2+) ions for a particular size of crown ether has been explained based on the fitting and binding interaction of the guest ions in the narrow cavity of crown ethers.

Role of transcranial Doppler ultrasonography in stroke.

Transcranial Doppler sonography is a non-invasive, non-ionising, inexpensive, portable and safe technique that uses a pulsed Doppler transducer for assessment of intracerebral blood flow. This article deals with the principles and technique of transcranial Doppler sonography. It gives a brief overview of its use in evaluation of intracranial steno-occlusive disease, subarachnoid haemorrhage, and extracranial diseases (including carotid artery disease and subclavian steal syndrome).

Stroke presentation in Type 2 diabetes and the metabolic syndrome.

Introduction: The metabolic syndrome (MetS) is associated with macrovascular disease and an altered pattern of cerebrovascular disease. We investigated stroke subtype presentation in Type 2 diabetic (T2D) patients, and analysed patients with and without the MetS.

Methods: We performed a retrospective analysis of 243 T2D patients with first presentation of stroke from our Diabetes Centre database.

Patent foramen ovale and atrial septal aneurysm in cryptogenic stroke.

Up to 40% of acute ischaemic strokes in young adults are cryptogenic in nature, that is, no cause is determined. In more than half of these patients, patent foramen ovale (PFO) is seen along with an increased incidence of atrial septal aneurysm. The commonest method of investigation is echocardiography (preferably transoesophageal echocardiography).

Cotinine, thioether, and glucuronide excretion among active and passive bidi smokers in India.

The authors examined biomarkers for environmental tobacco smoke exposure (ETS) from bidis (Indian cigarettes) among male smokers, their nonsmoking female family members (passive smokers), and an unexposed control group (N = 66). The 3 parameters used to determine the magnitude of exposure were cotinine (a tobacco-specific alkaloid indicating nicotine exposure) and thioethers and glucuronides (indicators of electrophilic burden). Urinary excretion of cotinine was significantly higher among active smokers (4.