Synthesis of MnFe2O4/activated carbon derived from durian shell waste for removal of indole in water: Optimization, modelling, and mechanism

While durian shell is often discharged into landfills, this waste can be a potential and zero-cost raw material to synthesize carbon-based adsorbents with purposes of saving costs and minimizing environmental contamination. Indole (IDO) is one of serious organic pollutants that influence aquatic species and human health; hence, the necessity for IDO removal is worth considering. Here, we synthesized a magnetic composite, denoted MFOAC, based on activated carbon (AC) derived from durian shell waste supported by MnFe2O4 (MFO) to adsorb IDO in water. MFOAC showed a microporous structure, along with a high surface area and pore volume, at 518.9 m2/g, and 0.106 cm3/g, respectively. Optimization of factors affecting the IDO removal of MFOAC were implemented by Box-Behnken design and response surface methodology. Adsorption kinetics and isotherms suggested a suitable model for MFOAC to remove IDO. MFOAC was recyclable with 3 cycles. Main interactions involving in the IDO adsorption mechanism onto MFOAC were clarified, including pore filling, n-π interaction, π-π interaction, Yoshida H-bonding, H-bonding.

Tecoma stans floral extract-mediated synthesis of MgFe2O4/ZnO nanoparticles for adsorption and photocatalytic degradation of coomassie brilliant blue dye

Toxic organic dyes-containing wastewater treatment by adsorption and photocatalytic techniques is widely applied, but adsorbents and photocatalysts are often synthesized through chemical methods, leading to secondary pollution by released chemicals. Here, we report a benign method using Tecoma stans floral extract to produce MgFe2O4/ZnO (MGFOZ) nanoparticles for adsorption and photocatalytic degradation of coomassie brilliant blue (CBB) dye. Green MGFOZ owned a surface area of 9.65 m2/g and an average grain size of 54 nm. This bio-based nanomaterial showed higher removal percentage and better recyclability (up to five cycles) than green MgFe2O4 and ZnO nanoparticles. CBB adsorption by MGFOZ was examined by kinetic and isotherm models with better fittings of Bangham and Langmuir or Temkin. RSM-based optimization was conducted to reach an actual adsorption capacity of 147.68 mg/g. Moreover, MGFOZ/visible light system showed a degradation efficiency of 89% CBB dye after 120 min. CBB adsorption can be controlled by both physisorption and chemisorption while •O2- and •OH radicals are responsible for photo-degradation of CBB dye. This study suggested that MGFOZ can be a promising adsorbent and catalyst for removal of organic dyes in water.

A critical review on the biosynthesis, properties, applications and future outlook of green MnO2 nanoparticles

MnO2 nanoparticles have played a vital role in biomedical, catalysis, electrochemical and energy storage fields, but requiring toxic chemicals in the fabrication intercepts their applications. There is an increasing demand for biosynthesis of MnO2 nanoparticles using green sources such as plant species in accordance with the purposes of environmental mitigation and production cost reduction. Here, we review recent advancements on the use of natural compounds such as polyphenols, reducing sugars, quercetins, etc. Extracted directly from low-cost and available plants for biogenic synthesis of MnO2 nanoparticles. Role of these phytochemicals and formation mechanism of bio-medicated MnO2 nanoparticles are shed light on. MnO2 nanoparticles own small particle size, high crystallinity, diverse morphology, high surface area and stability. Thanks to higher biocompatibility, bio-mediated synthesized MnO2 nanoparticles exhibited better antibacterial, antifungal, and anticancer activity than chemically synthesized ones. In terms of wastewater treatment and energy storage, they also served as efficient adsorbents and catalyst. Moreover, several aspects of limitation and future outlook of bio-mediated MnO2 nanoparticles in the fields are analyzed. It is expected that the present work not only expands systematic understandings of synthesis methods, properties and applications MnO2 nanoparticles but also pave the way for the nanotechnology revolution in combination with green chemistry and sustainable development.

The adverse skeletal effects of selective serotonin reuptake inhibitors

Selective serotonin reuptake inhibitors (SSRIs) are a widely used group of antidepressants (ADs) with reported potential detrimental effects on bone mineral density (BMD) and increased fracture risk. Here, a comprehensive review of the in vitro, in vivo and clinical studies to date was carried out using the medical search engines MEDLINE (1950 to September 2010) and EMBASE (1980 to September 2010). Serotonin (5-HT) receptors have been identified on osteoclast, osteoblast and osteocyte cell lines. The effect of SSRIs on bone formation and resorption appears to be governed by the activation of a number of 5-HT receptors on osteoblasts and osteoclasts via endocrine, autocrine/paracrine and neuronal pathways. In vitro, in vivo and clinical collective data appears to indicate that SSRIs have a negative effect on bone at the therapeutic dose levels widely used for the treatment of depression in current clinical practice. Caution may therefore have to be employed with the use of SSRIs in patients at an increased risk of falls and osteoporosis. Further studies are needed in order to fully elicit the role of SSRIs in bone formation and their effects in the low oestrogen state.

Mycophenolate mofetil treatment accelerates recovery from experimental allergic encephalomyelitis

Mycophenolate mofetil (MM) acts through its metabolite mycophenolic acid to inhibit inosine monophosphate dehydrogenase (IMPDH), an enzyme essential for purine synthesis in lymphocytes. Oral treatment with MM from the day of immunization for 2 weeks significantly delayed both the development of active experimental allergic encephalomyelitis (EAE) in Lewis rats and reduced the antibody response to myelin basic protein (MBP). MM did not deplete T and B cells, nor did it prevent induction of Th1 or Th2 cytokine in the regional nodes. Treatment of EAE with MM at the onset of clinical symptoms resulted in more rapid recovery from EAE than in control or cyclosporin A (CsA)-treated. MM-treated rats had less infiltration of T cells, B cells, macrophages and dendritic cells into brainstems than either the control or CsA-treated. MM-treated brainstems also had lower level of mRNA for Thl (IL-2, IL-12Rbeta2, IFN-gamma), Th2 (IL-4, IL-10) cytokines and TNF-alpha and TGF-beta compared to that in CsA and controls groups. This study shows MM was superior to CsA in the treatment of EAE and acted by reducing the inflammatory infiltrate, not by suppression of Ig response or by promotion of regulatory cells such as Th2 or Th3.

Reversal of experimental allergic encephalomyelitis with non-mitogenic, non-depleting anti-CD3 mAb therapy with a preferential effect on T(h)1 cells that is augmented by IL-4

This study examined whether therapy with a non-mitogenic, non-activating anti-CD3 mAb (G4.18) alone, or in combination with the T(h)2 cytokines, could inhibit induction or facilitate recovery from experimental allergic encephalomyelitis (EAE) in Lewis rats. G4.18, but not rIL-4, rIL-5 or anti-IL-4 mAb, reduced the severity and accelerated recovery from active EAE. A combination of rIL-4 with G4.18 was more effective than G4.18 alone. The infiltrate of CD4(+) and CD8(+) T cells, B cells, dendritic cells, and macrophages in the brain stem was less with combined G4.18 and IL-4 than G4.18 therapy or no treatment. Residual cells had preferential sparing of T(r)1 cytokines IL-5 and transforming growth factor-beta with loss of T(h)1 markers IL-2, IFN-gamma and IL-12Rbeta2, and the T(h)2 cytokine IL-4 as well as macrophage cytokines IL-10 and tumor necrosis factor-alpha. Lymph nodes draining the site of immunization had less mRNA for T(h)1 cytokines, but T(h)2 and T(r)1 cytokine expression was spared. Treatment with G4.18, rIL-4 or rIL-5 from the time of immunization had no effect on the course of active EAE. MRC OX-81, a mAb that blocks IL-4, delayed onset by 2 days, but had no effect on severity of active EAE. G4.18 also inhibited the ability of activated T cells from rats with active EAE to transfer passive EAE. This study demonstrated that T cell-mediated inflammation was rapidly reversed by a non-activating anti-CD3 mAb that blocked effector T(h)1 cells, and spared cells expressing T(h)2 and T(r)1 cytokines.