Adsorption of cadmium and lead from palm oil mill effluent using bone-composite: optimisation and isotherm studies

The adsorption of Cd and Pb ions from palm oil mill effluent on a mesoporous-activated cow bone composite powder has been investigated. Adsorbent was developed from cow bones, coconut shells and zeolite. The composite examined in the present work has a BET surface area of 248.398 m²/g. The optimisation of the removal efficiency of the heavy metals was investigated using central composite design and analysed using response surface methodology. The analysis of variance of the quadratic model signified that the model suitably predicted the uptake of the heavy metal ions at a 95% confidence level. The optimal operating condition was recorded at pH 4, 50 rpm, within 24 h and 1 mm of particle size and 12.5 gL^?1 of adsorbent dosage. The characteristics of the composite were investigated using the Fourier transform irradiation. The morphology and chemical composition of composite was examined using the scanning electron microscopy equipped with energy dispersive x-ray. Characterisation study was conducted before and after the adsorption process. The results obtained illustrated that the removal of cadmium and lead from POME was influenced by the functional groups available on the surface of the composite. The carboxyl and hydroxyl groups are mainly responsible for the removal of cadmium and lead through chelating process. The point of zero charge (pH_pzc) revealed that the adsorbent contained acidic sites with negatively charge surface which influenced the adsorption process. The experimental data of the heavy metals of Cd and Pb investigated were fitted to the Langmuir and Freundlich models. The result revealed that the adsorption equilibrium data fitted better to the Langmuir model for the adsorption Cd and to the Freundlich model for the adsorption of Pb.     

Synthesis and characterisation of complexes of iron(II,III), cobalt(II,III) and nickel(II) with dinitrosoresorcinol

Summary Complexes of Fe^II, Fe^III, Co^II, Co^III and Ni^II with dinitroso resercinol (DNR) have been isolated and characterised. Ni studies showed that the metals are coordinated to the oxygens of one hydroxyl and one nitroso group, the second hydroxyl and nitroso groups remaining uncoordinated. The magnetic moments of the Fe^II and Ni^II complexes are commensurate with tetrahedral (or disorted octahedral) structures, while the others are ocahedral, however, the electronic spectra suggest ocahedral stereochemistries for all the complexes.     

HPLC-DAD Based Polyphenolic Profiling and Evaluation of Pharmacological Attributes of Putranjiva roxburghii Wall.

The current study was intended to explore the phytochemical profiling and therapeutic activities of Putranjiva roxburghii Wall. Crude extracts of different plant parts were subjected to the determination of antioxidant, antimicrobial, antidiabetic, cytotoxic, and protein kinase inhibitory potential by using solvents of varying polarity ranges. Maximum phenolic content was notified in distilled water extracts of the stem (DW-S) and leaf (DW-L) while the highest flavonoid content was obtained in ethyl acetate leaf (EA-L) extract. HPLC-DAD analysis confirmed the presence of various polyphenols, quantified in the range of 0.02 ± 0.36 to 2.05 ± 0.18 μg/mg extract. Maximum DPPH scavenging activity was expressed by methanolic extract of the stem (MeOH-S). The highest antioxidant capacity and reducing power was shown by MeOH-S and leaf methanolic extract (MeOH-L), respectively. Proficient antibacterial activity was shown by EA-L extract against Bacillus subtilis and Escherichia coli. Remarkable α-amylase and α-glucosidase inhibition potential was expressed by ethyl acetate fruit (EA-F) and n-Hexane leaf (nH-L) extracts, respectively. In case of brine shrimp lethality assay, 41.67% of the extracts (LC₅₀ < 50 µg/mL) were considered as extremely cytotoxic. The test extracts also showed mild antifungal and protein kinase inhibition activities. The present study explores the therapeutic potential of P. roxburghii and calls for subsequent studies to isolate new bioactive leads through bioactivity-guided isolation.     

Anticancer Effects and Mechanisms of Berberine from Medicinal Herbs: An Update Review

Cancer has been a serious public health problem. Berberine is a famous natural compound from medicinal herbs and shows many bioactivities, such as antioxidant, anti-inflammatory, antidiabetic, anti-obesity, and antimicrobial activities. In addition, berberine shows anticancer effects on a variety of cancers, such as breast, lung, gastric, liver, colorectal, ovarian, cervical, and prostate cancers. The underlying mechanisms of action include inhibiting cancer cell proliferation, suppressing metastasis, inducing apoptosis, activating autophagy, regulating gut microbiota, and improving the effects of anticancer drugs. This paper summarizes effectiveness and mechanisms of berberine on different cancers and highlights the mechanisms of action. In addition, the nanotechnologies to improve bioavailability of berberine are included. Moreover, the side effects of berberine are also discussed. This paper is helpful for the prevention and treatment of cancers using berberine.     

Study of the physical properties of amorphous Zr doped Al2O3 powders

Alumina (Al₂O₃) powders doped with different amounts of zirconium (Zr) ions were synthesized by the sol-gel process. The Zr concentration was changed from 0 to 3%. Here we attempted to fabricate Zr doped Al₂O₃ samples and characterized them for their optical and structural properties. Ultraviolet-Visible analysis (UV-Vis), infrared spectroscopy (FT-IR) and powder X-ray diffraction (XRD) have been used to characterize the optical properties, phase evolution and crystallinity of the obtained samples. X-ray diffraction patterns revealed that all the Al₂O₃ powders obtained were completely amorphous. An optical study was employed to determine the band gap of the samples. The transmittance had decreased from 90 to 86% and the band gap of pure Al₂O₃ was found to be 4.116 eV, and it was shifted to 4.038 eV for 3% Zr doped Al₂O₃. The results obtained in this study are discussed comparatively with those cited in the literature.     

Multilayer films of cationic graphene-polyelectrolytes and anionic graphene-polyelectrolytes fabricated using layer-by-layer self-assembly

Extremely thin sheets of carbon atoms called graphene have been predicted to possess excellent thermal properties, electrical conductivity, and mechanical stiffness. To harness such properties in composite materials for multifunctional applications, one would require the incorporation of graphene. In this study, new thin film composites were created using layer-by-layer (LBL) assembly of polymer-coated graphitic nanoplatelets. The positive and negative polyelectrolytes used to cover graphene sheets were poly allylamine hydrochloride (PAH) and poly sodium 4-styrenesulfonate (PSS). The synthesized poly allylamine hydrochloride-graphene (PAH-G) and poly sodium 4-styrenesulfonate-gaphene (PSS-G) were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and thermo gravimetric analysis (TGA). The multilayer films created by spontaneous sequential adsorption of PAH-G and PSS-G were characterized by ultra violet spectroscopy (UV-vis), scanning electron microscopy (SEM), and AFM. The electrical conductivity of the graphene/polyelectrolyte multilayer film composites measured by the four-point probe method was 0.2 S cm⁻¹, which was sufficient for the construction of advanced electro-optical devices and sensors.