Facile auto-combustion synthesis of calcium aluminate nanoparticles for efficient removal of Ni(II) and As(III) ions from wastewater.

We herein report the synthesis of monoclinic calcium aluminate (CaAl2O4) nanoparticles via a facile auto-combustion method followed by calcination. We performed the auto-combustion method using aluminium nitrate and calcium nitrate as oxidants and different fuels as reductants such as urea, glycine, and a mixture of urea and glycine, with various fuel-to-oxidant equivalence ratios (Φc). Then, the combusted samples were calcined at different temperatures; 600 and 800 °C. The products were characterized by means of X-ray diffraction, Fourier transform infrared spectroscopy, thermo-gravimetric analysis, field-emission scanning electron microscope, and high-resolution transmission electron microscope. CaAl2O4 nanoparticles with an average crystallite size of 40.4, 38.8, and 33.7 nm were obtained after calcination at 800 °C using the aforementioned fuels, respectively. TEM images revealed that CaAl2O4 nanoparticles tend to form partially sintered aggregates owing to the high thermal treatment temperature, so they have non-uniform shapes. The produced CaAl2O4 nanoparticles exhibited good absorptivity toward Ni(II) and As(III) ions form aqueous media. The maximum sorption capacities (qm) of CaAl2O4 for the removal of Ni(II) and As(III) were found to be 58.73 and 43.9 mg.g-1, at pH 7 and 5, respectively. The equilibrium isotherms and adsorption kinetics studies revealed that the adsorption data fitted well Freundlich isotherm and pseudo-second-order models, respectively. Besides, the adsorption of Ni(II) and As(III) ions on CaAl2O4 nanoparticles is physisorption. Overall, the obtained results indicated that calcium aluminate nano-adsorbent is a good candidate for the removal of Ni(II) and As(III) ions from wastewater, due to its high efficiency, stability, and re-usability.

Efficacy of Regorafenib in Metastatic Colorectal Cancer: A Multi-institutional Retrospective Study.

BACKGROUND: Regorafenib is a multi-kinase inhibitor approved for treatment of refractory advanced colorectal cancer. It was found in the clinical trials to have a modest benefit and significant toxicity. Our aim was to assess the outcome in our local clinic practice. PATIENTS AND METHODS: Records of patients with confirmed colorectal cancer treated with regorafenib were reviewed. Clinical, pathological, and molecular data were collected. Efficacy and factors of possible prognostic significance were analyzed. RESULTS: A total of 78 patients with metastatic colorectal cancer were treated with regorafenib from February 2014 to February 2016 in 4 different institutions (median age: 50.5 years; male: 40 [51.3%]; KRAS mutant: 41 [52%]; right colonic primary: 18 [23%]). A total of 52 patients (66.7%) had Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 to 1, whereas in 25 patients (32.1%) it was >1. In total, 58 patients (74%) had dose reduction. No patient achieved objective response, 15 patients (19%) achieved stable disease, and 56 patients (72%) had progressive disease. With a median follow-up of 6.5 months, the median progression-free survival was 2.8 months (95% confidence interval [CI], 2.5-3.3) and overall survival was 8.0 months (95% CI, 6.2-9.7). Only performance status of ⩽1 had a statistically significant impact on progression-free survival and overall survival in both univariate and multivariate analyses. CONCLUSIONS: Regorafenib in our clinical practice has equal efficacy to reported data from pivotal registration trials. Our data suggest that performance status is the most important prognostic factor in patients treated with regorafenib, suggesting a careful selection of patients.

Clinico-pathological study of K-ras mutations in colorectal tumors in Saudi Arabia.

AIMS AND BACKGROUND: K-ras gene mutations contribute to the pathogenesis of colorectal cancer. We characterized K-ras mutations in colorectal tumors in patients in the Kingdom of Saudi Arabia, in terms of geographic area, age, gender, histology, stage, and anatomical localization. METHODS: Medical records and paraffin-embedded tumor samples from 150 consecutive patients with histologically proven colorectal adenocarcinoma referred to two centers in Saudi Arabia were analyzed using an LCD-array kit. RESULTS: K-ras mutations occurred in 56% of the patients; 48.7% of the mutations were in codon 12, most commonly p.G12V and p.G12D (each 35.6% of codon 12 mutations). Codon 13 mutations occurred in 7.3% of tumors: of these, most were p.G13D (90.9%) with the remainder p.G13R (9.1%). Codon 12 mutations overall were associated significantly with stage IVb tumors (P = 0.022) and rectal tumors (P = 0.028), with a trend of an association with a sigmoid location (P = 0.054). The p.G12V mutation was significantly associated with sigmoid tumors (P = 0.021) and negatively associated with left-sided tumors (P = 0.011), with a trend of an association with age ≥70 years (P = 0.062) and rectal tumors (P = 0.063). Other clinicopathological features were not significantly associated with K-ras mutations. CONCLUSIONS: K-ras mutations are common among the Saudi colorectal cancer population, especially pG12V and pG12D in codon 12, and are more frequent in sigmoid and rectal adenocarcinomas and stage IVB tumors.