A copper (II) ions biosorption by Sargassum sp. biomass was studied in a fixed bed column at 30 degrees C and pH 3.5. The experimental curves were obtained for the following feed concentrations -2.08, 4.16, 6.42 and 12.72mmol/L of the copper ions. The mathematical models developed by Thomas and Bohart-Adams were used for description of ions sorption process in the column. The models principle hypothesis is that the mass transfer controlling stage of the process is the adsorption kinetics between sorbate and adsorbent. The phenomena such as intraparticle diffusion, a mass transfer external resistance and axial dispersion effects were out of considerations. Some of the models parameters were experimentally determined (rho(B), epsilon, u(0), C(0)) and the others were evaluated on the bases of the experimental data (k(a1), k(a2)). The unique fitting parameter in all models was the adsorption kinetic constant. The identification procedure was based on the least square statistical method. Simulation results show that the models describe well a copper ions sorption process in a fixed bed column. The used models can be considered as useful tools for adsorption process design and optimization in fixed bed column by using algae biomass of Sargassum sp. as an adsorbent.
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http://dx.doi.org/10.1016/j.jhazmat.2007.07.005 | DOI Listing |
J Food Sci
December 2024
School of Life Science and Engineering, Henan University of Urban Construction, Pingdingshan, China.
This study aimed to investigate the potential of condensed tannins isolated from Cercis chinensis Bunge leaves as natural preservatives for fruits and vegetables. The research demonstrated that C. chinensis leaves condensed tannins (CLCT) significantly delay the browning process and reduce nutritional loss in fresh-cut lotus roots.
View Article and Find Full Text PDFJ Nanobiotechnology
December 2024
Key Laboratory of Emergency and Trauma of Ministry of Education, Engineering Research Center for Hainan Biological Sample Resources of Major Diseases, the Hainan Branch of National Clinical Research Center for Cancer, the First Affiliated Hospital, Hainan Medical University, Haikou, 570102, China.
Limited drug accumulation and an immunosuppressive microenvironment are the major bottlenecks in the treatment of glioblastoma multiforme (GBM). Herein, we report a copper-coordination driven brain-targeting nanoassembly (TCe6@Cu/TP5 NPs) for site-specific delivery of therapeutic agents and efficient immunotherapy by activating the cGAS-STING pathway and downregulating the expression of PD-L1. To achieve this, the mitochondria-targeting triphenylphosphorus (TPP) was linked to photosensitizer Chlorin e6 (Ce6) to form TPP-Ce6 (TCe6), which was then self-assembled with copper ions and thymopentin (TP5) to obtain TCe6@Cu/TP5 NPs.
View Article and Find Full Text PDFPathol Res Pract
December 2024
First Teaching Hospital, Tianjin University of Traditional Chinese Medicine, National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin 300193, China; Graduate School of Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China.
As an indispensable trace metal element in the organism, copper acts as a key catalytic cofactor in a wide range of biological processes. Copper homeostasis disorders can be caused by either copper excess or deficiency, and copper homeostasis disorders will affect the normal physiological functions of cells and induce cell death through a variety of mechanisms, such as the emerging cuproptosis model. The imbalance of copper homeostasis will lead to the occurrence of cancer, and copper is a key factor in cell signalling, so copper is involved in the development of cancer by promoting cell proliferation, angiogenesis and metastasis, etc.
View Article and Find Full Text PDFMikrochim Acta
December 2024
Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500, People's Republic of China.
A novel copper and iron doped containing chitosan and heparin sodium carbon dots (CS-Cu,Fe/HS) nanozyme was formulated through a single-step microwave digestion method. CS-Cu,Fe/HS exhibits excellent peroxidase (POD)-like activity and positive charge characteristics, and it can oxidize the negatively charged 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) in the presence of HO to produce a green compound (ox-ABTS). Furthermore, CS-Cu,Fe/HS enhances electron transfer and provides additional active sites through the valence state transformations of Fe/Fe and Cu/Cu.
View Article and Find Full Text PDFGels
December 2024
Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Ciencias Químicas, Ciudad Autónoma de Buenos Aires 1113, Argentina.
In this work, the mechanical properties of hydrogels based on linear polyethyleneimine (PEI) chemically crosslinked with ethyleneglycoldiglycidyl ether (EGDE) were improved by the ionic crosslinking with sodium tripolyphosphate (TPP). To this end, the quaternization of the nitrogen atoms present in the PEI structure was conducted to render a network with a permanent positive charge to interact with the negative charges of TPP. The co-crosslinking process was studied by H high-resolution magic angle spinning (H HRMAS) NMR and X-ray photoelectron spectroscopy (XPS) in combination with organic elemental analysis and inductively coupled plasma mass spectrometry (ICP-MS).
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