Comparative accuracy of CT perfusion in diagnosing acute ischemic stroke: A systematic review of 27 trials

<div><p>Objective</p><p>To systematically evaluate and compare the diagnostic accuracy of CT perfusion (CTP), non-enhanced computed tomography (NCCT) and computed tomography angiography (CTA) in detecting acute ischemic stroke.</p><p>Methods</p><p>We searched seven databases and screened the reference lists of the included studies. The risk of bias in the study quality was assessed using QUADASII. We produced paired forest plots in RevMan to show the variation of the sensitivity and specificity estimates together with their 95% CI. We used a hierarchical summary ROC model to summarize the sensitivity and specificity of CTP in detecting ischemic stroke.</p><p>Results</p><p>We identified 27 studies with a total of 2168 patients. The pooled sensitivity of CTP for acute ischemic stroke was 82% (95% CI 75–88%), and the specificity was 96% (95% CI 89–99%). CTP was more sensitive than NCCT and had a similar accuracy with CTA. There were no statistically significant differences in the sensitivity and specificity between patients who underwent CTP within 6 hours of symptom onset and beyond 6 hours after symptom onset. No adverse events were reported in the included studies.</p><p>Conclusions</p><p>CTP is more accurate than NCCT and has similar accuracy to CTA in detecting acute ischemic stroke. However, the evidence is not strong. There is potential benefit of using CTP to select stroke patients for treatment, but more high-quality evidence is needed to confirm this result.</p></div

Evaluating the Transcriptomic and Metabolic Profile of Mice Exposed to Source Drinking Water

Transcriptomic and metabonomic methods were used to investigate mice’s responses to drinking source water (DSW) exposure. After mice were fed with DSW for 90 days, hepatic transcriptome was characterized by microarray and serum metabonome were determined by ¹H nuclear magnetic resonance (NMR) spectroscopy. A total of 243 differentially expressed genes (DEGs) were identified, among which 141 genes were up-regulated and 102 genes were down-regulated. Metabonomics revealed significant changes in concentrations of creatine, pyruvate, glutamine, lysine, choline, acetate, lipids, taurine, and trimethylamine oxide. Four biological pathways were identified by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis where both gene expression and metabolite concentrations were altered in response to DSW exposure. These results highlight the significance of combined use of transcriptomic and metabonomic approaches in evaluating potential health risk induced by DSW contaminated with various hazardous materials

Characteristics of included studies.

<p>Characteristics of included studies.</p

Forest plot of CTP and NCCT for detection of ischemic stroke.

<p>Forest plot of CTP and NCCT for detection of ischemic stroke.</p

Summary ROC Plot of CTP and NCCT for detecting ischemic stroke.

<p>Each ellipse on the plot represents the study estimate of CTP. Each diamond represents the study estimate of NCCT. Red and black solid circles represent the summary sensitivity and specificity for NCCT and CTP respectively, and this summary point is surrounded by a 95% confidence region (dotted line). Red and black solid lines represent HSROC curve of NCCT and CTP respectively.</p

Risk of bias and applicability concerns graph: Review authors’ judgments about each domain presented as percentages across included studies.

<p>Risk of bias and applicability concerns graph: Review authors’ judgments about each domain presented as percentages across included studies.</p

Risk of bias and applicability concerns summary.

<p>Risk of bias and applicability concerns summary.</p

Summary ROC Plot of CTP and CTA for detecting ischemic stroke.

<p>Each ellipse on the plot represents the study estimate of CTP. Each diamond represents the study estimate of CTA. Red and black solid circles represent the summary sensitivity and specificity for CTA and CTP respectively, and these summary points are surrounded by a 95% confidence region (dotted line). Red and black solid lines represent HSROC curve of CTA and CTP respectively.</p

Forest plot of CTP for detection of ischemic stroke.

<p>The plot shows study-specific estimates of sensitivity and specificity (with 95% confidence intervals). The studies are ordered according to whether recruitment was prospective or not, and sensitivity. FN: false negative; FP: false positive; TN: true negative; TP: true positive.</p

Enhanced Removal of Fluoride by Polystyrene Anion Exchanger Supported Hydrous Zirconium Oxide Nanoparticles

Here we fabricated a novel nanocomposite HZO-201, an encapsulated nanosized hydrous zirconium oxide (HZO) within a commercial porous polystyrene anion exchanger D201, for highly efficient defluoridation of water. HZO-201 exhibited much higher preference than activated alumina and D201 toward fluoride removal when competing anions (chloride, sulfate, nitrate, and bicarbonate) coexisted at relatively high levels. Fixed column adsorption indicated that the effective treatable volume of water with HZO-201 was about 7–14 times as much as with D201 irrespective of whether synthetic solution or groundwater was the feeding solution. In addition, HZO-201 could treat >3000 BV of the acidic effluent (around 3.5 mg F^–/L) per run at pH 3.5, compared to only ∼4 BV with D201. The exhausted HZO-201 could be regenerated by NaOH solution for repeated use without any significant capacity loss. Such attractive performance of HZO-201 resulted from its specific hybrid structure, that is, the host anion exchanger D201 favors the preconcentration of fluoride ions inside the polymer based on the Donnan principle, and the encapsulated nanosized HZO exhibits preferable sequestration of fluoride through specific interaction, as further demonstrated by XPS spectra. The influence of solution pH, competitive anions, and contact time was also examined. The results suggested that HZO-201 has a great potential in efficient defluoridation of groundwater and acidic mine drainage