Removal of Levofloxacin from aqueous solution by Magnesium-impregnated Biochar: batch and column experiments

<p>Adsorption of levofloxacin (LEV) onto four types of magnesium (Mg)-impregnated biochars, fabricated via thermal pyrolysis of wood chips pretreated with MgSO₄ was investigated. The Mg-impregnated biochars were characterized with various tools and techniques. Batch sorption experiments were conducted to determine the sorption kinetics and isotherms of LEV onto the Mg-impregnated biochars. The pseudo-second order kinetic model described the adsorption kinetic data better than the pseudo-first order kinetic model and the Elovich equation. Due to multi-mechanisms, the Freundlich model described the experimental isotherms better than the Langmuir model. The Langmuir maximum adsorption capacities of the Mg-impregnated biochars to LEV ranged from 7.38 to 25.2 mg g⁻¹. In the fixed-bed column experiment, higher bed height and lower flow rate led to greater LEV removal. Findings from this work indicate that Mg-impregnated biochars can be used as an alternative adsorbent to effectively remove LEV from aqueous solutions.</p

SRSF1 Facilitates Cytosolic DNA-Induced Production of Type I Interferons Recognized by RIG-I

<div><p>Background</p><p>Evidence has shown that psoriasis is closely associated with infection; however, the mechanism of this association remains unclear. In mammalian cells, viral or bacterial infection is accompanied by the release of cytosolic DNA, which in turn triggers the production of type-I interferons (IFNs). Type I IFNs and their associated genes are significantly upregulated in psoriatic lesions. RIG-I is also highly upregulated in psoriatic lesions and is responsible for IFN production. However, RIG-I mediated regulatory signaling in psoriasis is poorly understood.</p><p>Methods</p><p>We screened a cDNA library and identified potential RIG-I interacting partners that may play a role in psoriasis.</p><p>Results</p><p>We found that serine/arginine-rich splicing factor 1 (SRSF1) could specifically interact with RIG-I to facilitate RIG-I mediated production of type-I IFN that is triggered by cytosolic DNA. We found SRSF1 associates with RNA polymerase III and RIG-I in a DNA-dependent manner. In addition, treatment with a TNFα inhibitor downregulated SRSF1 expression in peripheral blood mononuclear cells (PBMCs) from psoriasis vulgaris patients.</p><p>Discussion</p><p>Based on the abundance of pathogenic cytosolic DNA that is detected in psoriatic lesions, our finding that RIG-I interacts with SRSF1 to regulate type-I IFN production reveals a critical link regarding how cytosolic DNA specifically activates aberrant IFN expression. These data may provide new therapeutic targets for the treatment of psoriasis.</p></div

Downregulated SRSF1 in psoriasis patients after treatment and <i>SRSF1</i> knockdown decreases type I IFN production.

<p>A. <i>SRSF1</i> mRNA levels in PBMCs from patients with psoriasis at week 0 or after 12 weeks of treatment with adalimumab. B. Specific <i>SRSF1</i> knockdown was evaluated in PBMCs transfected with <i>SRSF1</i> siRNA or scrambled siRNA. PBMC samples are from two psoriasis patients before drug treatment. Cells were combined and electroporated with scrambled siRNA or <i>SRSF1</i> siRNA. C. IFN-β concentration in the supernatant of samples stimulated for 24 h with 1 μg/mL poly(dA:dT)/LyoVec for 24hrs. D. IL-6, TNFα, and IL-1β concentration in the supernatant of samples stimulated for 24 h with 1 μg/mL poly(dA:dT)/LyoVec.</p

XRD patterns of xerogels.

<p>(A) GO sheets; (B) C16Py-GO gels in DMF (a), THF (b), and pyridine (c); (C) BPy-GO gels in DMF (a), cyclopentanone (b), and THF (c); (D) CTAB-GO gels in DMF (a), cyclopentanone (b), cyclohexanone (c), 1,4-dioxane (d), and THF (e).</p

SEM images of xerogels. GO sheets (a), C16Py-GO gels ((b) DMF, (c) THF, and (d) pyridine), BPy-GO gels ((e) DMF, (f) cyclopentanone, and (g) THF), and CTAB-GO gels ((h) DMF, (i) cyclopentanone, (j) cyclohexanone, (k) 1,4-dioxane, and (l) THF).

<p>SEM images of xerogels. GO sheets (a), C16Py-GO gels ((b) DMF, (c) THF, and (d) pyridine), BPy-GO gels ((e) DMF, (f) cyclopentanone, and (g) THF), and CTAB-GO gels ((h) DMF, (i) cyclopentanone, (j) cyclohexanone, (k) 1,4-dioxane, and (l) THF).</p

SRSF1 interacts with RIG-I <i>in vitro</i> and <i>in vivo</i>.

<p>A. HEK293T cells were transfected with Flag-RIG-I, Flag-MDA5, Flag-MAVS, FLAG-TBK1, Flag-IKKi, Flag-IRF3, and HA-SRSF1. Flag-tagged proteins were immunoprecipitated using anti-Flag beads and immunoblotted with the HA antibody. B. HEK293T cells were transfected with Flag-tagged cGAS, STING, or RIG-I and HA-tagged SRSF1. Flag-tagged proteins were immunoprecipitated using anti-Flag beads and immunoblotted with the anti-HA antibody. C. THP-1 cells were lysed in low-salt lysis buffer. Cell lysates were immunoprecipitated with the control antibody or the anti-RIG-I antibody, and incubated overnight with protein (A+G). Immunoprecipitated products were immunoblotted with the anti-SRSF1 antibody. WCL, whole cell lysate.</p

Typical EDXS of xerogels originate from CTAB-GO gels in cyclopentanone.

<p>The Cu and Au peaks originate from the substrate of copper foil and the coated gold nanoparticles.</p

TGA data of GO sheet and amphiphiles-GO xerogels.

<p>TGA data of GO sheet and amphiphiles-GO xerogels.</p

TG curves of xerogels.

<p>(A) GO sheet and C16Py-GO gels in DMF, THF, and pyridine; (B) GO sheet and BPy-GO gels in DMF, cyclopentanone, and THF; (C) GO sheet and CTAB-GO gels in DMF, cyclopentanone, cyclohexanone, 1,4-dioxane, and THF.</p

The association of SRSF1 with RNA polymerase III is dependent on the DNA template.

<p>(A) HEK293T cells were transfected with salmon sperm DNA and lysed using RIPA buffer. Cell lysates were immunoprecipitated with the RNA polymerase III subunit C7 antibody and immunoblotted using the SRSF1 antibody. Lysates were left untreated or were treated for 1 h with RNase A or DNase I before immunoprecipitation. (B) HEK293T cells were stimulated with 500 ng Poly(dA:dT)/LyoVec. After 24 h, cell lysates were immunoprecipitated with the anti-RIG-I antibody or anti-Pol-III RPC32 antibody and incubated overnight with protein(A+G). Immunoprecipitated products, as well as 1% input from whole cell lysates, were immunoblotted with anti-SRSF1, anti-RIG-I, and anti-Pol III antibodies.</p