Correction: DCID-mediated esterification of carboxylic acids with alcohols under mild conditions.

[This corrects the article DOI: 10.1039/D3RA04048H.].

Cobalt sulfide flower-like derived from metal organic frameworks on nickel foam as an electrode for fabrication of asymmetric supercapacitors.

Metal-organic frameworks, as a kind of advanced nanoporous materials with metal centers and organic linkers, have been applied as promising electrode materials in energy storage devices. In this study, we are successfully prepared cobalt sulfide nanosheets (CoS) derived from the metal-organic framework on nickel foam (NF). The prepared electrodes are characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, Brunauer-Emmett-Teller and Barrett-Joyner-Halenda and electrochemical methods like voltammetry, galvanostatic charge-discharge curve and electrochemical impedance spectroscopy. The CoS/NF electrode demonstrates a high specific capacity of 377.5 mA h g-1 (1359 C g-1) at the current density of 2 A g-1, considerable rate performance and excellent durability (89.4% after 4000 cycles). A hybrid supercapacitor is assembled using CoS/NF as the positive electrode and activated carbon as the negative electrode, it shows a high energy density of 57.4 W h kg-1 at a power density of 405.2 W kg-1. The electrochemical results suggest that the CoS nanosheet arrays would possess excellent potential for applications in energy storage devices.

DCID-mediated esterification of carboxylic acids with alcohols under mild conditions.

DCID (Dichloroimidazolidinedione) 2 is used as a novel coupling reagent for the esterification of carboxylic acids with alcohols at room temperature. The reaction represents the first DCID-promoted esterification under mild conditions with good to excellent yields. Reactions can proceed smoothly with those bearing electron-withdrawing and donating group(s) on the carboxylic acids and benzyl alcohols at ambient temperature. Furthermore, we proposed a plausible mechanism and confirmed it by isolating and characterizing intermediates 3a and 7. The structures of the synthesized compounds were confirmed by comparison of melting points and NMR spectra.

The Failure Rate, Related Factors, and Neonate Complications of Vaginal Delivery after Cesarean Section.

BACKGROUND: The rate of Cesarean Section (CS) is high in Iran. A successful Vaginal Birth After Cesarean (VBAC) section can protect mothers against the risk of having multiple CS. This study aimed to evaluate the success rate of VBAC, related factors, and the causes of failure. MATERIALS AND METHODS: This cross-sectional study was conducted on 150 pregnant women who were candidates for VBAC and admitted at maternity hospitals in Qom from 2016 to 2018. The required data were collected from the patients' records and entered into the checklist. Then, the success rate of VBAC was estimated, and related factors together with the causes of failure were determined by t-test, Chi-square, and independent-samples t-tests in SPSS v. 18 software. RESULTS: The mean (SD) maternal age was 32 (5.20) years and ranged from 21 to 45 years old. The success rate of VBAC was estimated to be 85.33%, and 14.67% of the patients had to repeat a CS after failure in vaginal delivery. The mean time between previous CS and present delivery was statistically significant between successful and failure groups (t 125 = 2.32, p = 0.002). The results also revealed that the most important causes of VBAC failure were prolonged labor [odds ratio (OR) = 4.70)], full arrest (OR = 2.70), and decline fetal heart (OR = 5.31). CONCLUSIONS: The success rate of VBAC in our study was high. However, VBAC was more successful when the interval between inter-deliveries was long, and lower complications were reported when the interval was 2-4 years.

Preparation, optimization, and in-vitro characterization of α-tocopherol-loaded solid lipid nanoparticles (SLNs).

Objective: The main scope of present investigation was preparation and physicochemical characterization of solid lipid nanoparticles (SLNs) loaded by α-tocopherol acetate (ATA).Methods: ATA-loaded nanoparticles were prepared by solvent injection-homogenization technique using stearic acid as the solid lipid, phosphatidylcholine as the stabilizer and finally coated by chitosan with the aim of increasing z-potential and also having a more stable nano-formulation. Then, characterization of SLNs has been conducted using dynamic light scattering (DLS), zeta potential measurement, Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC).Results: Nanoparticles with average sizes of 175 ± 15 nm and zeta potential of +35 ± 2.5 mV were obtained. An excellent drug entrapment efficiency of 90.58 ± 1.38% was obtained with a no-burst slow release up to about 10 days tested. The final plateau of release of ATA from nanoparticulate system within 216 h was 61.13 ± 0.13% which was approached in about 150 h. Physical stability studies showed that the ATA nano-formulation remained stable with slight increase in mean particle size and polydispersity index over a 3-month period in refrigerated temperature. Considering both FTIR and DSC analysis, it can be concluded that there is no new band formation between materials and ATA in our nano-formulation. Particle sizes obtained using AFM images are in a good agreement to those established from the DLS analysis.Conclusion: These data showed a promising delivery system for vitamin E based on SLN platform.