PERFORMANCE EVALUATION OF GREEN INHIBITORS IN CHLORIDE INDUCED CORROSION OF REINFORCING STEEL EMBEDDED IN CONCRETE

Abstract This study investigates the corrosion inhibition efficiency of some organic inhibitors and compares its performance against inorganic inhibitors. The inorganic inhibitors used in the study were sodium molybdate dihydrate (Na2MoO4·2H2O), benzotriazole, while organic inhibitors were prepared from Azadirachta indica (AI) and Calotropis gigantea (CG) plant. The concrete specimens were contaminated during concrete preparation with 2% NaCl by weight of cement. To evaluate the effect of these inhibitors on corrosion of reinforcing steel, cylindrical concrete specimens with centrally embedded reinforcement were prepared. Further to accelerate the corrosion process the specimens after curing period were exposed to NaCl(4%) solution. Concrete cube specimens were used to evaluate the effect of inhibitors on the compressive strength of concrete. The results of the study indicated that the corrosion inhibitors investigated in this study did not have adverse effects on compressive strength of concrete. Furthermore, Benzotriazole proved to be effective in delaying corrosion initiation of reinforcing steel embedded in concrete specimens contaminated with NaCl compared to Na2MoO4·2H2O. Observing the performance of both organic inhibitors, AI inhibitor performed better in mitigating the reinforcing steel corrosion compared to CG

A systematic review and meta-analysis of the diagnostic accuracy of pyruvate kinase M2 isoenzymatic assay in diagnosing colorectal cancer

BACKGROUND: Screening programmes exist in many countries for colorectal cancer. In recent years, there has been a drive for a non-invasive screening marker of higher sensitivity and specificity. Stool-based pyruvate kinase isoenzyme M2 (M2-PK) is one such biomarker under investigation. The aim of this systematic review and meta-analysis is to determine the diagnostic accuracy, sensitivity and specificity of M2-PK as a screening tool in colorectal cancer. METHODS: A literature search of Ovid Medline, EMBASE and Google Scholar was carried out. The search strategy was restricted to human subjects and studies published in English. Data on sensitivity and specificity were extracted and pooled. Statistical analysis was conducted using summary receiver operating characteristic (SROC) curve methodology. RESULTS: A total of eight studies were suitable for data synthesis and analysis. Our analysis showed a pooled sensitivity and specificity for M2-PK to be 79% (CI 73%–83%) and 80% (CI 73%–86%), respectively. The accuracy of M2-PK was 0.85(0.82–0.88). CONCLUSION: Faecal M2-PK assay has a relatively good sensitivity and specificity and high accuracy for screening colorectal cancer

Biodegradation of polyethylene and polypropylene

9-22Polyethylene and polypropylene are the two polyolefins with wide ranging applications. They are recalcitrant and hence remain inert to degradation and deterioration leading to their accumulation in the environment, and, therefore creating serious environmental problems. In this review, biodegradation of these two polymers under in vitro conditions is reported. An attempt has been made to cover the mechanism of biodegradation, the various bacterial and fungal organisms that have been reported for the same, methods adopted for the studies and different characterization techniques followed to measure the extent of degradatio

CT colonography for surveillance of patients with colorectal cancer: Systematic review and meta-analysis of diagnostic efficacy

Purpose: To review primary research evidence investigating performance of CT colonography for colorectal cancer surveillance. The financial impact of using CT colonography for surveillance was also estimated. Methods: We identified primary studies of CT colonography for surveillance of colorectal cancer patients. A summary ROC curve was constructed. Inter-study heterogeneity was explored using the I2 value. Financial impact was estimated for a theoretical cohort of patients, based on Cancer Research UK statistics. Results: Seven studies provided data on 880 patients. Five of seven studies (765 patients) were included for qualitative analysis. Sensitivity of CT colonography for detection of anastomotic recurrence was 95 % (95 % CI 62 − 100), specificity 100 % (95 % CI 75 − 100) and sensitivity for metachronous cancers was 100 %. No statistical heterogeneity was detected (I2 = 0 %). We estimated that CT colonography as a 'single test' alternative to colonoscopy and standard CT for surveillance would potentially save €20,785,232 (£14,803,404) for an annual cohort of UK patients. Conclusion: CT colonography compares favourably to colonoscopy for detection of anastomotic recurrence and metachronous colorectal cancer, and appears financially beneficial. These findings should be considered alongside limitations of small patient numbers and high clinical heterogeneity between studies. Key Points: • CT colonography compares favourably to colonoscopy/standard CT for colorectal cancer surveillance. • CT colonography offers single-test luminal, serosal and extra-colonic assessment. • CT colonography is a potentially cost-saving alternative to standard surveillance protocols