Preparation and pore-forming mechanism of hydrogen bond and ionic bond double-driven chitosan-based mesoporous carbon

Direct carbonization of cellulose toward hydroxyl-rich porous carbons for pseudocapacitive energy storage

Designing carbon materials with specific oxygen-containing functional groups is very attractive for the precise decoration of carbon electrode materials and the basic understanding of specific charge storage mechanisms, which contributes to the further development of high-performance carbon materials for energy storage and conversion applications. In this contribution, a hydroxyl-rich micropore-dominated porous carbon material was obtained by direct carbonization of cellulose. The content of oxygen atoms in hydroxyl form in the obtained carbon is nearly 6 at.%. With the pyrolysis temperature changed, the macroscopic morphology, the specific surface area, surface functional groups, and graphitization degree of the carbon materials were changed strongly. Besides, the carbon material obtained with a carbonization temperature of 900 °C (C9) showed enhanced specific capacitance in sulfuric acid, sodium hydroxide, and sodium sulfate aqueous electrolytes, which mainly originates from the contribution of pseudocapacitance. The pseudocapacitance mainly depends on the presence of surface hydroxyl functional groups. Besides, the pseudocapacitance value of C9 material in neutral electrolytes (151.34 F g-1) is about twice that in acidic (75.9 F g-1) and alkaline (75.78 F g-1) electrolytes.

Synthesis of Aminomethylpyridine-Decorated Polyamidoamine Dendrimer/Apple Residue for the Efficient Capture of Cd(II)

Water contamination irritated by Cd(II) brings about severe damage to the ecosystem and to human health. The decontamination of Cd(II) by the adsorption method is a promising technology. Here, we construct aminomethylpyridine-functionalized polyamidoamine (PAMAM) dendrimer/apple residue biosorbents (AP-G1.0-AMP and AP-G2.0-AMP) for adsorbing Cd(II) from aqueous solution. The adsorption behaviors of the biosorbents for Cd(II) were comprehensively evaluated. The maximum adsorption capacities of AP-G1.0-AMP and AP-G2.0-AMP for Cd(II) are 1.40 and 1.44 mmol·g-1 at pH 6. The adsorption process for Cd(II) is swift and can reach equilibrium after 120 min. The film diffusion process dominates the adsorption kinetics, and a pseudo-second-order model is appropriate to depict this process. The uptake of Cd(II) can be promoted by increasing concentration and temperature. The adsorption isotherm follows the Langmuir model with a chemisorption mechanism. The biosorbents also display satisfied adsorption for Cd(II) in real aqueous media. The adsorption mechanism indicates that C-N, N═C, C-O, CONH, N-H, and O-H groups participate in the adsorption for Cd(II). The biosorbents display a good regeneration property and can be reused with practical value. The as-prepared biosorbents show great potential for removing Cd(II) from water solutions with remarkable significance.

A Nature-Inspired Separator with Water-Confined and Kinetics-Boosted Effects for Sustainable and High-Utilization Zn Metal Batteries

Uncontrollable dendrite growth and sluggish ion-transport kinetics are considered as the main obstacles for the further development of high-performance aqueous zinc ion batteries (AZIBs). Here, a nature-inspired separator (ZnHAP/BC) is developed to tackle these issues via the hybridization of the biomass-derived bacterial cellulose (BC) network and nano-hydroxyapatite particles (HAP). The as-prepared ZnHAP/BC separator not only regulates the desolvation process of the hydrated Zn²⁺ ions (Zn(H₂ O)₆ ²⁺ ) by suppressing the water reactivity through the surface functional groups, alleviating the water-induced side-reactions, but also boosts the ion-transport kinetics and homogenize the Zn²⁺ flux, resulting in a fast and uniform Zn deposition. Remarkably, the Zn|Zn symmetric cell with ZnHAP/BC separator harvests a long-term stability over 1600 h at 1 mA cm^-2 , 1 mAh cm^-2 and endures stable cycling over 1025 and 611 h even at a high depth of discharge (DOD) of 50% and 80%, respectively. The Zn|V₂ O₅ full cell with a low negative/positive (N/P) capacity ratio of 2.7 achieves a superior capacity retention of 82% after 2500 cycles at 10 A g^-1 . Furthermore, the Zn/HAP separator can be totally degraded within 2 weeks. This work develops a novel nature-derived separator and provides insights in constructing functional separators toward sustainable and advanced AZIBs.

An Immunoinformatics Approach to Design a Potent Multi-Epitope Vaccine against Asia-1 Genotype of Crimean-Congo Haemorrhagic Fever Virus Using the Structural Glycoproteins as a Target

Crimean-Congo haemorrhagic fever (CCHF), caused by Crimean-Congo haemorrhagic fever virus (CCHFV), is a disease of worldwide importance (endemic yet not limited to Asia, Middle East, and Africa) and has triggered several outbreaks amounting to a case fatality rate of 10-40% as per the World Health Organization. Genetic diversity and phylogenetic data revealed that the Asia-1 genotype of CCHFV remained dominant in Pakistan, where 688 confirmed cases were reported between the 2012-2022 period. Currently, no approved vaccine is available to tackle the viral infection. Epitope-based vaccine design has gained significant attention in recent years due to its safety, timeliness, and cost efficiency compared to conventional vaccines. In the present study, we employed a robust immunoinformatics-based approach targeting the structural glycoproteins G1 and G2 of CCHFV (Asia-1 genotype) to design a multi-epitope vaccine construct. Five B-cells and six cytotoxic T-lymphocytes (CTL) epitopes were mapped and finalized from G1 and G2 and were fused with suitable linkers (EAAAK, GGGS, AAY, and GPGPG), a PADRE sequence (13 aa), and an adjuvant (50S ribosomal protein L7/L12) to formulate a chimeric vaccine construct. The selected CTL epitopes showed high affinity and stable binding with the binding groove of common human HLA class I molecules (HLA-A*02:01 and HLA-B*44:02) and mouse major histocompatibility complex class I molecules. The chimeric vaccine was predicted to be an antigenic, non-allergenic, and soluble molecule with a suitable physicochemical profile. Molecular docking and molecular dynamics simulation indicated a stable and energetically favourable interaction between the constructed antigen and Toll-like receptors (TLR2, TLR3, and TLR4). Our results demonstrated that innate, adaptive, and humoral immune responses could be elicited upon administration of such a potent muti-epitope vaccine construct. These results could be helpful for an experimental vaccinologist to develop an effective vaccine against the Asia-1 genotype of CCHFV.

Contriving multi-epitope vaccine ensemble for monkeypox disease using an immunoinformatics approach

The current global outbreak of monkeypox (MPX) disease, caused by Monkeypox virus (MPXV), has resulted in 16 thousand infection cases, five deaths, and has been declared a global health emergency of international concern by the World Health Organization. Given current challenges in the safety of existing vaccines, a vaccine to prevent MPX infection and/or onset of symptoms would significantly advance disease management. In this context, a multi-epitope-based vaccine could be a well-suited approach. Herein, we searched a publicly accessible database (Virus Pathogen Database and Analysis Resource) for MPXV immune epitopes from various antigens. We prioritized a group of epitopes (10 CD8+ T cells and four B-cell epitopes) using a computer-aided technique based on desirable immunological and physicochemical properties, sequence conservation criteria, and non-human homology. Three multi-epitope vaccines were constructed (MPXV-1–3) by fusing finalized epitopes with the aid of appropriate linkers and adjuvant (beta-defensin 3, 50S ribosomal protein L7/L12, and Heparin-binding hemagglutinin). Codon optimization and in silico cloning in the pET28a (+) expression vector ensure the optimal expression of each construct in the Escherichia Coli system. Two and three-dimensional structures of the constructed vaccines were predicted and refined. The optimal binding mode of the construct with immune receptors [Toll-like receptors (TLR2, TLR3, and TLR4)] was explored by molecular docking, which revealed high docking energies of MPXV-1–TLR3 (–99.09 kcal/mol), MPXV-2–TLR3 (–98.68 kcal/mol), and MPXV-3–TLR2 (–85.22 kcal/mol). Conformational stability and energetically favourable binding of the vaccine-TLR2/3 complexes were assessed by performing molecular dynamics simulations and free energy calculations (Molecular Mechanics/Generalized Born Surface Area method). In silico immune simulation suggested that innate, adaptive, and humoral responses will be elicited upon administration of such potent multi-epitope vaccine constructs. The vaccine constructs are antigenic, non-allergen, non-toxic, soluble, topographically exposed, and possess favourable physicochemical characteristics. These results may help experimental vaccinologists design a potent MPX vaccine.

Design of a Recombinant Multivalent Epitope Vaccine Based on SARS-CoV-2 and Its Variants in Immunoinformatics Approaches

The development of an effective multivalent vaccine against SARS-CoV-2 variants is an important means to improve the global public health situation caused by COVID-19. In this study, we identified the antigen epitopes of the main global epidemic SARS-CoV-2 and mutated virus strains using immunoinformatics approach, and screened out 8 cytotoxic T lymphocyte epitopes (CTLEs), 17 helper T lymphocyte epitopes (HTLEs), 9 linear B-cell epitopes (LBEs) and 4 conformational B-cell epitopes (CBEs). The global population coverage of CTLEs and HTLEs was 93.16% and 99.9% respectively. These epitopes were spliced together by corresponding linkers and recombined into multivalent vaccine. In silico tests, the vaccine protein was a non-allergen and the docking with TLR-3 molecule showed a strong interaction. The results of immune simulation showed that the vaccine may be helpful to initiate both cellular and humoral immunity against all VOC. The optimistic immunogenicity of the vaccine was confirmed in vivo and in vitro finally. Therefore, our vaccine may have potential protection against SARS-CoV-2 and its variants.

Toxicological effects of leachate extracts from asphalt mixtures nanomodified under Daphnia magna and Landoltia punctata test organisms

The incorporation of nanomaterials in binders in the paving area has been studied to improve the mechanical behavior of asphalt mixtures. However, asphalt mixture compounds are susceptible to leaching and deposition in the environment. In this context, this research aimed to investigate the toxic effect of two leachate extracts from asphalt mixtures nanomodified with 2% carbon nanotube and 3% organophilic nanoclay, compared to conventional mixture, using Daphnia magna and Landoltia punctata as test organisms. The nanomaterials were characterized to confirm morphology, stability and effective diameter. Extracts were chemically characterized using the Fourier-Transform Infrared Spectroscopy (FTIR) technique, which indicated presence of functional groups of the asphalt binder in greater intensity in the leachate from conventional mixture. Acute toxicity with D. magna indicated EC_50,48h of 83.5 ± 6.2 mL/L for leachate extract from conventional mixture, 306.0 ± 87.6 mL/L for leachate extract from mixture with nanoclay and 464.8 ± 32.1 mL/L for leachate extract from mixture with carbon nanotube. No leachate caused significant chronic toxicity. As for L.punctata, concentrations that caused 50% growth inhibition were 127.5 mL/L for the leachate extract from mixture with carbon nanotube, 196.9 mL/L for the leachate extract from mixture with nanoclay and 205 mL/L for the leachate extract from conventional mixture. For these test organisms, there is no evidence of negative impacts directly associated with the use of the present nanomaterials in asphalt mixtures. The incorporation of these nanos may also reduce the acute toxicity of the mixtures.

Optimization of catalytic wet oxidating fulvic acid with zero-valent copper chitosan activated carbon ball as the catalyst

The degradation efficiency of fulvic acid (FA) was investigated in the catalytic wet oxidation process (CWPO) by zero-valent copper chitosan activated carbon ball (ZVC/CTS-ACB). Characterization of ZVC/CTS-ACB shows that zero-valent copper was loaded successfully on the chitosan activated carbon. Plackett-Buiman (PB) design and response surface methodology (RSM) were employed to determine the influence factors and the optimum processing parameters. The model was well fitted to the actual data and the correlation coefficients of R2 and R2-adj were 0.9359 and 0.9039, respectively. Under the obtained optimum conditions for FA degradation: temperature = 94 °C and pH 3.8, the average FA removal by three replicate experiments was 93.02%, which has a high consistency to the RSM optimal target response of 93.86%. The comparison of catalytic performance showed that the addition of catalyst ZVC/CTS-ACS could increase the removal rate of FA, color number (CN) and TOC by 93.6%, 83.5% and 81.9% respectively. The high TOC removal rate indicated the good performance of the catalyst to FA mineralization. Additionally, the ICP analysis of copper ion leaching was only 0.08 mg/l after 5 repeated recycles of the catalyst, demonstrating the high stability of ZVC/CTS-ACB that is beneficial for the actual application.