Correction: A novel, efficient and magnetically recyclable Cu-Ni bimetallic nanocomposite as a highly active bifunctional catalyst for Pd-free Sonogashira and C-N cross-coupling reactions: a combined theoretical and experimental study.

[This corrects the article DOI: 10.1039/D3RA01965A.].

A novel, efficient and magnetically recyclable Cu-Ni bimetallic alloy nanoparticle as a highly active bifunctional catalyst for Pd-free Sonogashira and C-N cross-coupling reactions: a combined theoretical and experimental study.

In this study, a Fe3O4@SiO2@Cyt-Ni/Cu nanocomposite as a novel heterogeneous bimetallic catalyst was synthesized which exhibits efficient performance for the Sonogashira and C-N cross-coupling reactions. The characterization of the catalyst was studied by FT-IR, PXRD, VSM, EDX, TEM, FE-SEM and TGA analyses. The geometry optimization and relative energies of the designed bimetallic complexes were theoretically determined using density functional theory (DFT) calculation at the B3LYP/6-31G**/LANL2DZ level. The catalyst showed good activity in the coupling of various aryl halides with alkynes (Sonogashira reaction) as well as aryl halide with N-heterocycles and achieved coupling products with good to high yields for all of them in a short time. The high catalytic performance could be due to the synergistic effect between Ni and Cu, which causes the reaction to proceed more efficiently. This heterogeneous nanocatalyst could be easily recovered from the reaction mixture with an external magnet and reused for 7 consecutive runs with minimal loss of catalytic activity.

Dental Erosion in Patients with Gastroesophageal Reflux Disease (GERD) in a Sample of Patients Referred to the Motahari Clinic, Shiraz, Iran.

STATEMENT OF PROBLEM: Systematic reviews of the literature show that the dental erosion is associated with the gastroesophageal reflux disease (GERD).The prevalence of the problem may not be exclusively similar in different countries. PURPOSE: The purpose of this study was to investigate the association of gastro-esophageal reflux disease (GERD) with dental erosion in a sample of Iranian population regarding the standing difference in the Iranian oral hygiene and diet. Material s and Method: 140 patients with the average age of 30 to 50 years old comprised the study group. The participants were already eligible for the endoscopic examination, diagnosed by their gastroenterologist. All patients completed a detailed questionnaire regarding the medical and dental situations. After completing the questionnaire and before endoscopy, dental examination was performed by two blinded dentists.The endoscopy was then performed by a gastroenterologist and the patients were divided into three groups of healthy, suspected to GERD, and positive GERD. Data were collected and analyzed by Chi- Square test. The cross tabulation test was performed to compare the qualitative variants and discover the correlations. The statistical significance was adopted as: p < 0.05. RESULTS: The prevalence of dental erosion in GERD patients (22.6%) was found to be higher than the suspected (5.3%) and the healthy (7%) individuals. CONCLUSION: This study declared the GERD patients are at higher risk of developing dental erosion compared to the healthy individuals in a sample of Iranian population.

Movement of bromacil in a Hawaii soil under pineapple cultivation - a field study.

Recent discovery of low concentrations of bromacil in drinking water prompted the State of Hawaii to examine the leaching behavior of bromacil in pineapple fields. This study is a follow up to earlier work on bromacil concentrations in soil profiles in a pineapple field in central Oahu, Hawaii. Soil samples were collected for bromacil analysis at different times prior to and after application from a pineapple field that was previously surveyed by other research workers. The leaching pattern of bromacil was further investigated at two different application rates (2.25 and 1.8 kg ha(-1)). The concentration of bromacil in the topsoil about 100 days after bromacil application (1.8 kg ha(-1)) was substantially higher in 2002 compared to 1999. The distribution profiles were generally consistent with the one presented in the previous study. Residual bromacil was present in the entire sampled zone (3m deep) about 18 months after the previous bromacil application. Over a period of 9 months, there was substantial dissipation of bromacil residue present in the topsoil. The residual concentration of bromacil in the area that received the reduced application rate (1.8 kg ha(-1)) were lower than those receiving the current application rate (2.25 kg ha(-1)) and the depth of penetration of the bromacil front was shallower at the reduced application rate. Because of the common practice of placing plastic mulch around the base of the pineapple plants to retain volatile nematicides, the applied bromacil was found to be concentrated in the areas between the plastic mulch, transported by runoff from the plastic. The study results encourage the use of less than the label led rate of application of bromacil for pineapple fields.