Utilization of Corn Cob and TiO2 Photocatalyst Thin Films for Dyes Removal.

The effectiveness of using TiO2 and corn cob films to remove Malachite Green oxalate (MG) and Acid Yellow 17 (AY 17) from binary dye solution was studied. The immobilization method in this study can avoid the filtration step which is not suited for practical applications. Batch studies were performed under different experimental conditions and the parameters studied involved initial pH of dye solution, initial dye concentration and contact time and reusability. The equilibrium data of MG and AY 17 conform to Freundlich and Langmuir isotherm model, respectively. The percentage removal of MG remained high after four sorption cycles, however for AY 17, a greater reduction was observed. The removal of both dyes were optimized and modeled via Plackett- Burman design (PB) and Response Surface Methodology (RSM). IR spectrum and surface conditions analyses were carried out using fourier-transform infrared spectrophotometer (FTIR), scanning electron microscope (SEM) and atomic force microscope (AFM), respectively.

Associations of retinal microvascular signs and intracranial large artery disease.

BACKGROUND AND PURPOSE: Intracranial large artery disease (ICLAD) is a major cause of ischemic stroke. Retinal microvascular changes are associated with stroke, including small vessel cerebral disease and extracranial carotid disease. We examined the relationship between ICLAD and retinal microvascular changes. METHODS: This is a prospective cohort of 802 acute ischemic stroke patients. Retinal changes were assessed from photographs by graders masked to clinical data. ICLAD was evaluated using prespecified criteria. RESULTS: ICLAD was not associated with ipsilateral retinal arteriolar/venular caliber, focal arteriolar narrowing, or arteriovenous nicking. Severe enhanced arteriolar light reflex was independently associated with any ICLAD (P=0.006) and severe ICLAD (P<0.001). CONCLUSIONS: Enhanced arteriolar light reflex, but not retinal vessel caliber, was related to ICLAD. These data suggest that retinal microvascular signs have specific associations with large cerebral vessel disease.

Arterial stiffness is associated with intracranial large artery disease among ethnic Chinese and South Asian ischemic stroke patients.

OBJECTIVE: Intracranial large artery disease (ICLAD) is a common stroke subtype that carries a poor prognosis. We studied the association of arterial stiffness, a recognized risk factor for atherosclerosis and ICLAD among ethnic Chinese and South Asian ischemic stroke patients. METHODS: In this prospective study, we recruited consecutive ischemic stroke patients of Chinese and South Asian ethnicity. ICLAD was assessed by transcranial color-coded Doppler or magnetic resonance angiographic studies. Arterial stiffness was measured by carotid-femoral pulse wave velocity (cPWV). RESULTS: Among the 268 patients studied, the prevalence of ICLAD was 54% and median cPWV was 11.4 m/s (interquartile range 9.0-13.6 m/s). Patients with ICLAD had higher cPWV compared with those without (median 11.7 vs. 11.0 m/s, P = 0.015). In multivariate analysis, patients with ICLAD were significantly more likely to have cPWV measurements in the highest quintile (>14.1 m/s) compared with patients without ICLAD independently of other covariates [odds ratio 2.21, P = 0.038]. CONCLUSION: This study revealed a novel association between arterial stiffness and ICLAD among ischemic stroke patients. The findings suggest that arterial stiffness may be involved in the pathophysiology of ICLAD. Future studies should investigate the effects of reducing arterial stiffness among stroke patients with ICLAD.

Efficacy of dual antiplatelet therapy in cerebrovascular disease as demonstrated by a decline in microembolic signals. A report of eight cases.

BACKGROUND: The presence of microembolic signals (MES) may indicate an increased risk of recurrent ischemic events in patients with stroke. The optimal management of such patients is uncertain. We report the effect of clopidogrel in addition to aspirin on the number of MES in a series of patients with ischemic stroke and transient ischemic attack (TIA) due to large-vessel disease. METHODS: 8 patients with either extracranial or intracranial artery stenosis were identified in 30-min MES studies by transcranial Doppler sonography as having MES. All patients were on antiplatelet therapy prior to baseline transcranial Doppler monitoring. The patients were subsequently treated with clopidogrel in addition to aspirin. Repeat MES studies were performed between day 3 and 7 with aspirin and clopidogrel. RESULTS: All patients were Chinese. The median interval time from symptom onset to initial MES study was 7 days (range of 2-30). MES donor sites included 4 severely stenosed or occluded internal carotid arteries and 4 stenosed middle cerebral arteries. The median MES number at baseline was 8 (range 3-51). Repeat MES studies showed a significant decrease in MES (p = 0.012, Wilcoxon signed ranks test). 4 patients had complete cessation of MES and all patients showed a decline in MES. No patient had recurrent strokes or bleeding complications. CONCLUSION: The rapid and significant decline of MES in our stroke and TIA patients suggests the possible efficacy of dual antiplatelet therapy with aspirin and clopidogrel in patients with MES and symptomatic large-artery occlusive disease. Randomized controlled trials should be conducted to confirm this preliminary observation.