Statistical analyses on effective removal of cadmium and hexavalent chromium ions by multiwall carbon nanotubes (MWCNTs).

In this work, multiwall carbon nanotubes (MWCNTs) developed from cobalt-ferrite catalyst on activated carbon (from castor seed), was used as an adsorbent for the removal of cadmium and hexavalent chromium ions. The effectiveness of the adsorbent for the uptake of Cd(II) and Cr(VI)ions from aqueous solution was investigated in a process batch adsorption study. The developed activated carbon and MWCNTs were characterized by Brunauer-Emmett-Teller (BET) surface area analysis, Fourier Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM) for the determination of surface area, functional group, and surface morphology, respectively. The BET surface area of activated carbon and developed adsorbent from Co-Fe/AC was 230.24 and 372.42 m2/g, respectively. The operational parameters evaluated on the adsorption efficiency were solution pH, temperature, adsorbent dosage initial metal ions concentration, and contact time. The adsorption of Cd(II) and Cr(VI) were found to have attained equilibrium positions in 60 min for the concentration range tested, respectively. The four linearized adsorption isotherm models; Langmuir, Freundlich, Temkin and Dubinin Radushkevich (D-R) tested, when compared, revealed that Langmuir isotherm fitted well to the experimental data judging from the higher correlation coefficient values (R2) and lower values of the error functions (chi-square (χ2), the sum of square error (ERRSQ/SSE) and the sum of absolute error (EABS))with monolayer adsorption capacities of 404.858 and 243.902 mg/g for Cd(II) and Cr(VI) ions, respectively. Adsorption kinetic models investigated by pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion showed the conformity of pseudo-second-order model to the process adsorption as informed by the higher values R2 and Adj, R2, maximum log-likelihood and smaller ERRSQ/SSE, χ2, Akaike information criterion (AIC), Bayesian information criterion (BIC), and Hannan-Quinn information criterion (HQIC). The intraparticle diffusion model plots indicated that intraparticle diffusion was not the only rate-limiting step. Thermodynamic adsorption parameters (ΔHo and ΔGo, ΔSo) showed that the adsorption of Cd (II) and Cr (VI) ions was spontaneous, endothermic, and increased in randomness between the adsorbate-adsorbent. The mean adsorption energy (E), the heat of adsorption (ΔHo), and activation energy (Ea) values, revealed the adsorption mechanism of Cd(II) and Cr(VI) onto MWCNTs as a combination of chemical and physical adsorption but dominated more by chemical adsorption.

Optimization of chicken nail extracts as corrosion inhibitor on mild steel in 2M H2SO4.

The inhibiting effects of Chicken Nails Extract (CNE) on Mild Steel corrosion in 2M H2SO4 were investigated in this study. The effect of the concentration of inhibitor (0.5-1.5 g/l), time (5-8 h) and temperature (40-70oc) on Inhibition efficiency were investigated using Response Surface Methodology. The Physiochemical analysis and proximate analysis of the CNE were investigated; the result showed that organic constituents were present which made the Chicken nails extract a good inhibitor. The rate of corrosion increases as time and temperature increase while the Inhibition efficiency was discovered to increase as the inhibitor concentration increases. The optimum conditions obtained were temperature 63.63 °C, time 5 h and inhibitor concentration of 0.1 g/l. The optimum Inhibition Efficiency at these optimum conditions was predicted to be 74.04%. The micrographs result of Scanning Electron Micrographs analysis showed that in the presence of the inhibitor, there was a passive layer of a film formed on the surface. This study revealed that Chicken Nails Extract is a potentially good green inhibitor for Mild steel corrosion in 2M H2SO4.

Prognostic value of neutrophil-to-lymphocyte ratio in castration resistant prostate cancer: Single-centre study of Nigerian men.

BACKGROUND: Elevated neutrophil-to-lymphocyte ratio (NLR) has been suggested to be a useful prognosticator of overall survival (OS) in several cancers including castration resistant prostate cancer. However, its utility in black populations known to have benign ethnic neutropenia is unknown. We evaluated the prognostic value of NLR in Nigerian men with CRPC in terms of OS. MATERIALS AND METHODS: We retrospectively analysed 58 patients with castration resistant prostate cancer who received androgen deprivation therapy (ADT) and docetaxel chemotherapy at our institution. Baseline NLR was calculated from available complete blood counts. NLR cut-off point value was determined based on receiver operator characteristic (ROC) curves for mortality. A multivariate analysis was performed to investigate the association between NLR and OS. RESULTS: Based on the ROC curves, the NLR (AUC 0.85, 95% CI 0.74-0.97, P = 0.0001) cut-off point was determined to be 1.8. This cut-off point has a sensitivity of 92% and specificity of 70%. Median OS was 20 months (95% CI 14-27 months); the median OS in patients with NLR <1.8 and those with NLR of ≥1.8 was 40 months and 12 months respectively. Kaplan-Meier plots showed that a higher NLR of ≥1.8 correlated significantly with an increased risk of mortality, Log rank P = 0.001. Multivariate Cox regression analyses confirmed NLR as an independent prognostic biomarker for OS (HR = 1.49, 95% CI: 1.18-1.87). CONCLUSIONS: This study demonstrated that NLR is a useful prognostic biomarker in Nigerian men with CRPC and that elevated baseline NLR ≥1.8 is associated with poorer OS.

Concealed enterovesical fistula associated with forgotten intra-abdominal haemostat and intravesical towel.

Introduction. Enterovesical fistula is rare and is often caused by bowel inflammatory diseases and tumours in the urinary bladder or the intestine with local infiltration of bowel or bladder, respectively. The fistula usually presents with lower urinary tract symptoms, pneumaturia, and faecaluria or with food particles in the urine. Intra-abdominal retained surgical foreign bodies have also been reported as causes. Case Presentation. A case of atypical presentation in a woman with enterovesical fistula following abdominal hysterectomy. Investigations confirmed the presence of surgical towel in the urinary bladder and a pair of artery forceps in the abdomen. The towel was removed at cystoscopy after which she presented with food particles in the urine. She later had laparatomy to remove the haemostat and to repair the fistula. Discussion. A typical presentation of enterovesical fistula delayed the diagnosis and treatment in this patient. Conclusion. Managing patients with recurrent urinary tract infection after abdominal operation should include appropriate imaging of the abdomen with emphasis on pelvic organs. Also, surgical operation should always be given the best shot the first time and strict operation room standards and guidelines should always be followed.