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Currently, pathogenic microorganisms are becoming more active in public utility areas like parking lots and waste shelters due to the accumulation of organic waste. This uncontrolled waste leads to decay, altering its composition and presenting a microbiological risk to public health. Additionally, it emits unpleasant odors containing chemicals that irritate the mucous membranes, causing discomfort in the nose, throat, and eyes by stimulating the trigeminal nerve. These odors can have various negative effects on both quality of life and public health. The study investigated the physicochemical properties of oil composites enriched with natural additives and determined their effectiveness in reducing the intensity of nuisance odours. The research showed over 82% reduction in decaying meat odour and almost 65% reduction in ammonia odour. A higher impact of the given composites on reducing the odour from decaying meat than from ammonia was observed. This may be due to the biocidal properties of the additives used (turmeric, thymol, salicylic acid, hops and curly sorrel) and the higher intensity of ammonia odor compared to meat-derived odour. Despite the non-porous nature of the solids tested (with similar specific surface areas ranging from 0.66 to 0.88 m2/g), they were capable of sorbing NH3.
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Odorantes , Odorantes/análise , Culinária , Amônia/química , Carne , AnimaisRESUMO
Oxygen interaction with the carbon surface is one of the most important topics of study in the field of material chemistry. In this work, experimental evidence for molecular oxygen dissociative chemisorption on a carbon surface at room temperature is shown for the first time. It was determined that the process occurs only on the bare carbon surface, and the quantitative description of the phenomena is possible using the Temkin model, which explains an almost linear decrease in the calorimetric heat of adsorption. The results provided by in situ infrared studies show that surface carbonyl oxides appear as intermediates of final functionality, i.e., carbonyl structures. Examining the thermal stability of surface structures shows that all surface species decompose at temperatures below 500 °C, leaving a pristine carbon surface.
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Liquid hydrogen carriers will soon play a significant role in transporting energy. The key factors that are considered when assessing the applicability of ammonia cracking in large-scale projects are as follows: high energy density, easy storage and distribution, the simplicity of the overall process, and a low or zero-carbon footprint. Thermal systems used for recovering H2 from ammonia require a reaction unit and catalyst that operates at a high temperature (550-800 °C) for the complete conversion of ammonia, which has a negative effect on the economics of the process. A non-thermal plasma (NTP) solution is the answer to this problem. Ammonia becomes a reliable hydrogen carrier and, in combination with NTP, offers the high conversion of the dehydrogenation process at a relatively low temperature so that zero-carbon pure hydrogen can be transported over long distances. This paper provides a critical overview of ammonia decomposition systems that focus on non-thermal methods, especially under plasma conditions. The review shows that the process has various positive aspects and is an innovative process that has only been reported to a limited extent.
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Amônia , Gases em Plasma , Transporte Biológico , Carbono , Temperatura Baixa , HidrogênioRESUMO
Non-thermal plasma (NTP) application in medicine is a dynamically developing interdisciplinary field. Despite the fact that basics of the plasma phenomenon have been known since the 19th century, growing scientific attention has been paid in recent years to the use of plasma in medicine. Three most important plasma-based effects are pivotal for medical applications: (i) inactivation of a broad spectrum of microorganisms, (ii) stimulation of cell proliferation and angiogenesis with lower plasma treatment intensity, and (iii) inactivation of cells by initialization of cell death with higher plasma intensity. In this review, we explain the underlying chemical processes and reactive species involvement during NTP in human (or animal) tissues, as well as in bacteria inactivation, which leads to sterilization and indirectly supports wound healing. In addition, plasma-mediated modifications of medical surfaces, such as surgical instruments or implants, are described. This review focuses on the existing knowledge on NTP-based in vitro and in vivo studies and highlights potential opportunities for the development of novel therapeutic methods. A full understanding of the NTP mechanisms of action is urgently needed for the further development of modern plasma-based medicine.
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Medicina , Gases em Plasma , Animais , Humanos , Morte Celular , Proliferação de Células , Estudos Interdisciplinares , Plasma , Gases em Plasma/farmacologia , Gases em Plasma/uso terapêuticoRESUMO
Biodegradable metal systems are the future of modern implantology. This publication describes the preparation of porous iron-based materials using a simple, affordable replica method on a polymeric template. We obtained two iron-based materials with different pore sizes for potential application in cardiac surgery implants. The materials were compared in terms of their corrosion rate (using immersion and electrochemical methods) and their cytotoxic activity (indirect test on three cell lines: mouse L929 fibroblasts, human aortic smooth muscle cells (HAMSC), and human umbilical vein endothelial cells (HUVEC)). Our research proved that the material being too porous might have a toxic effect on cell lines due to rapid corrosion.
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Purinergic signaling, the oldest evolutionary transmitter system, has been increasingly studied as a pivotal target for novel anti-cancer therapies. In the present work, the developed nanobiocatalytic system consisting of adenylate kinase immobilized on graphene oxide (AK-GO) was characterized in terms of its physicochemical and biochemical properties. We put special emphasis on the AK-GO influence on purinergic signaling components, that is, ecto-nucleotides concentration and ecto-enzymes expression and activity in human lung carcinoma epithelial (A549) cells. The immobilization-dependent modification of AK kinetic parameters allowed for the removal of ATP excess while maintaining low ATP concentrations, efficient decrease in adenosine concentration, and control of the nucleotide balance in carcinoma cells. The cyto- and hemocompatibility of developed AK-GO nanobiocatalytic system indicates that it can be successfully harnessed for biomedical applications. In A549 cells treated with AK-GO nanobiocatalytic system, the significantly decreased adenosinergic signaling results in reduction of the proliferation and migration capability of cancer cells. This finding is particularly relevant in regard to AK-GO prospective anti-cancer applications.
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Adenilato Quinase , Carcinoma , Humanos , Adenilato Quinase/metabolismo , Células Epiteliais/metabolismo , Trifosfato de Adenosina/metabolismo , Pulmão/metabolismoRESUMO
Despite the importance of quantum dots in a wide range of biological, chemical, and physical processes, the structure of the molecular layers surrounding their surface in solution remains unknown. Thus, knowledge about the interaction mechanism of Nitrogen enriched Carbonaceous Quantum Dots' (N-CQDs) surface with water-their natural environment-is highly desirable. A diffusive and Stern layer over the N-CQDs, characterized in situ, reveals the presence of anionic water clusters [OH(H2O)n]-. Their existence explains new observations: (i) the unexpectedly low adsorption enthalpy (ΔHads) in a pressure range below 0.1 p/ps, and ΔHads being as high as 190 kJ/mol at 0.11 p/ps; (ii) the presence of a "conductive window" isolating nature-at p/ps below 0.45-connected to the formation of smaller clusters and increasing conductivity above 0.45 p/ps, (iii) Stern layer stability; and (iv) superhydrophilic properties of the tested material. These observables are the consequences of H2O dissociative adsorption on N-containing basic centers. The additional direct application of surfaces formed by N-CQDs spraying is the possibility of creating antistatic, antifogging, bio-friendly coatings.
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Pontos Quânticos , Pontos Quânticos/química , Nitrogênio/química , Carbono/química , ÁguaRESUMO
Rapid growth in the mass production of nanomaterials together with their abundant use in consumer products, progressively increases the potential risks of living organisms exposure. Some unique properties of nanomaterials and nanoparticles facilitate their interactions with biomolecules (nano-bio interactions). The purinergic signalling system is one of the oldest evolutionary and widespread transmitter system that utilizes extracellular purine nucleotides and nucleosides as chemical messengers. However, interactions between nanomaterials and components of purinergic signalling pathway have not been fully recognized so far. In view of the emerging data, we summarize the current state-of-art and present the perspectives of nanomaterials influence on the functions of purinergic signaling pathway in different types of cells. The described nano-bio interactions include inter alia direct interplay with purinergic receptors or altering receptor genes expression, activation of inflammatory processes, and induction of cell death. However, the precise mechanisms are yet still to be disentangled. Due to the fact that majority of the effects ascribed to nanomaterials seems to induce disordered signalling, these interactions cannot stay neglected. A better understanding of signalling modulations induced by nanomaterials is not only essential for the accurate assessment of their toxicity, but also for synthesis and design of novel, safer nanomaterials.
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Nanopartículas , Nanoestruturas , Receptores Purinérgicos/metabolismo , Purinas/metabolismo , Nanoestruturas/química , Transdução de Sinais , Nanopartículas/químicaRESUMO
Due to easy storage and transportation, liquid hydrogen carriers will play a significant role in diversifying the energy supply pathways by transporting hydrogen on a large scale. Thus, in this study, amorphous carbonaceous materials have been employed for hydrogen production via ammonia decomposition under non-thermal plasma (NTP) conditions. The adsorption and splitting of ammonia over carbons differing in the chemical structure of surface functional groups have been investigated by in situ spectral studies directly under NTP conditions. As a result of NH3 physical and chemical sorption, surface species in the form of ammonium salts, amide and imide structures decompose immediately after switching on the plasma environment, and new functionalities are formed. Carbon catalysts are very active for NH3 splitting. The determined selectivity to H2 is close to 100% on N-doped carbon material. The data obtained indicate that the tested materials possess excellent catalytic ability for economical, COx-free hydrogen production from NH3 at a low temperature.
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Amônia , Gases em Plasma , Amônia/química , Carbono/química , Catálise , Hidrogênio/química , Espectroscopia de Infravermelho com Transformada de Fourier , TemperaturaRESUMO
Pentoxifylline is a xanthine derivative used in vascular disorders that is recognized as a safe drug for patients. The paper describes a rare case of fatal and suicidal pentoxifylline poisoning in an 82-year-old man with multiple preexisting diseases (arterial hypertension, coronary artery disease, type 2 diabetes, and intermittent claudication). The patient was admitted to the clinical toxicology unit approximately 2 h after the overdose and died 36 h after the admission despite intensive care. Multiple arterial blood gas analyses and other laboratory tests were performed during the hospitalization and are reported in the paper. Postmortem examination of the biological material was carried out with the use of histopathological techniques. The toxicological studies using chromatographic techniques coupled with mass spectrometry showed that postmortem blood levels of pentoxifylline have been found in the range which is described in the available literature to be toxic and lethal. The analysis of test results and clinical data showed that the patient died as a result of increasing circulatory and respiratory failure, complicated by disorders of the acid-base and electrolyte balance (respiratory alkalosis, concomitant lactic acidosis, and hypokalemia), hyperglycemia, and coagulation disorders.
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Porous iron-based scaffolds were prepared by the simple replica method using polyurethane foam as a template and applying the sintering process in a tube furnace. Their surface morphology was characterized using scanning electron microscopy (SEM) and phase homogeneity was confirmed using X-ray diffraction (XRD). Corrosion behavior was determined using immersion and potentiodynamic polarization methods in phosphate buffered saline (PBS). The surface energy was calculated by studying the changes of enthalpy of calorimetric immersion. A preliminary biological test was also carried out and was done using the albumin adsorption procedure. Results of our work showed that in using the simple replica method it is possible to obtain iron biomaterial with morphology and mechanical properties almost identical to bones, and possessing adequate wettability, which gives the potential to use this material as biomaterial for scaffolds in orthopedics.
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Titanium dioxide is one of the best described photosensitive materials used in photocatalysis, solar cells, self-cleaning coatings, and sunscreens. The scientific and industrial attention has been focused on the highly photoactive crystalline phase of titanium dioxide (TiO2). It is commonly accepted that the smaller TiO2 particles, the higher photoactivity they present. Therefore, titanium dioxide nanoparticles are massively produced and widely used in everyday products. The amorphous phase of titanium dioxide has been treated with neglect, as the lack of its photocatalytic properties is assumed in advance. In this work, the complex experimental proof of the UV-protective properties of the nano-sized amorphous TiO2 phase is reported. Amorphous n-TiO2 is characterized by photocatalytic inactivity and, as a consequence, low cytotoxicity to fibroblast cells. When exposed to UV radiation, cells with amorphous TiO2 better survive under stress conditions. Thus, we postulate that amorphous n-TiO2 will be more beneficial and completely safe for cosmetic applications. Moreover, the results from in situ FTIR studies let us correlate the low toxicity of amorphous samples with low ability to form hydroperoxo surface species.
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Cosméticos , Nanopartículas , Nanopartículas/química , Titânio/química , Raios UltravioletaRESUMO
We report a new structure of {[Co(bpy)2(ox)][{Cu2(bpy)2(ox)}Fe(ox)3]}n·8.5nH2O NCU-1 presenting a rare ladder topology among oxalate-based coordination polymers with anionic chains composed of alternately arranged [Cu2(bpy)2(ox)]2+ and [Fe(ox)3]3- moieties. Along the a axis, they are separated by Co(III) units to give porous material with voids of 963.7 Å3 (16.9% of cell volume). The stability of this structure is assured by a network of stacking interactions and charge-assisted C-H O hydrogen bonds formed between adjacent chains, adjacent cobalt(III) units, and alternately arranged cobalt(III) and chain motifs. The soaking experiment with acetonitrile and bromobenzene showed that water molecules (8.5 water molecules dispersed over 15 positions) are bonded tightly, despite partial occupancy. Water adsorption experiments are described by a D'arcy and Watt model being the sum of Langmuir and Dubinin-Serpinski isotherms. The amount of primary adsorption sites calculated from this model is equal 8.2 mol H2O/mol, being very close to the value obtained from the XRD experiments and indicates that water was adsorbed mainly on the primary sites. The antiferromagnetic properties could be only approximately described with the simple CuII-ox-CuII dimer using H = -J·S1·S2, thus, considering non-trivial topology of the whole Cu-Fe chain, we developed our own general approach, based on the semiclassical model (SC) and molecular field (MF) model, to describe precisely the magnetic superexchange interactions in NCU-1. We established that Cu(II)-Cu(II) coupling dominates over multiple Cu(II)-Fe(III) interactions, with JCuCu = -275(29) and JCuFe = -3.8(1.6) cm-1 and discussed the obtained values against the literature data.
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Fenômenos Magnéticos , Metais/química , Oxalatos/química , Adsorção , Cristalização , Dimerização , Ligação de Hidrogênio , Modelos Moleculares , Conformação Molecular , Espectrofotometria Infravermelho , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Água/química , Espectroscopia por Absorção de Raios XRESUMO
The interaction between graphene oxide (GO) and lysozyme (LYZ) in aqueous solution was investigated for GO specific surface area determination and for the thermodynamic description of the process. It was experimentally proved that LYZ is a much better adsorbate than the most common methylene blue, allowing the determination of genuine GO surface area. Our fluorescence spectroscopy results indicate that LYZ molecules interact with GO at high- and low-affinity sites depending on the surface coverage, reflecting the protein mono- and multilayer formation, respectively. The lack of the secondary structure changes confirms LYZ usability as a model adsorbate. The calculated values of thermodynamic parameters (Δ(ΔH0) = -195.0 kJ/mol and Δ(ΔS0) = -621.3 J/molK) indicate that the interactions are exothermic, enthalpy-driven. All the reported results reveal the physical nature of the LYZ-GO interaction at the studied concentration ratios.
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Grafite , Muramidase , Adsorção , Grafite/química , Muramidase/química , TermodinâmicaRESUMO
The existing clinical protocols of hepatoma treatment require improvement of drug efficacy that can be achieved by harnessing nanomedicine. Porphyrin-based, paddle-wheel framework (PPF) structures were obtained and tested as dual-kinetic Sorafenib (SOR) nanocarriers against hepatoma. We experimentally proved that sloughing of PPF structures combined with gradual dissolving are effective mechanisms for releasing the drug from the nanocarrier. By controlling the PPF degradation and size of adsorbed SOR deposits, we were able to augment SOR anticancer effects, both in vitro and in vivo, due to the dual kinetic behavior of SOR@PPF. Obtained drug delivery systems with slow and fast release of SOR influenced effectively, although in a different way, the cancer cells proliferation (reflected with EC50 and ERK 1/2 phosphorylation level). The in vivo studies proved that fast-released SOR@PPF reduces the tumor size considerably, while the slow-released SOR@PPF much better prevents from lymph nodes involvement and distant metastases.
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Carcinoma Hepatocelular/tratamento farmacológico , Sistemas de Liberação de Medicamentos/métodos , Neoplasias Hepáticas/tratamento farmacológico , Estruturas Metalorgânicas/uso terapêutico , Porfirinas/uso terapêutico , Sorafenibe/uso terapêutico , Animais , Antineoplásicos/farmacologia , Materiais Biocompatíveis/uso terapêutico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Liberação Controlada de Fármacos , Humanos , Sistema de Sinalização das MAP Quinases , Nanomedicina , Fosforilação , Ratos , Ratos Sprague-DawleyRESUMO
The oxidative properties of nanomaterials arouse legitimate concerns about oxidative damage in biological systems. On the other hand, the undisputable benefits of nanomaterials promote them for biomedical applications; thus, the strategies to reduce oxidative potential are urgently needed. We aimed at analysis of nitrogen-containing carbon quantum dots (N-CQDs) in terms of their biocompatibility and internalization by different cells. Surprisingly, N-CQD uptake does not contribute to the increased oxidative stress inside cells and lacks cytotoxic influence even at high concentrations, primarily through protein corona formation. We proved experimentally that the protein coating effectively limits the oxidative capacity of N-CQDs. Thus, N-CQDs served as an immobilization support for three different enzymes with the potential to be used as therapeutics. Various kinetic parameters of immobilized enzymes were analyzed. Regardless of the enzyme structure and type of reaction catalyzed, adsorption on the nanocarrier resulted in increased catalytic efficiency. The enzymatic-protein-to-nanomaterial ratio is the pivotal factor determining the course of kinetic parameter changes that can be tailored for enzyme application. We conclude that the above properties of N-CQDs make them an ideal support for enzymatic drugs required for multiple biomedical applications, including personalized medical therapies.
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Biocatálise , Carbono/química , Carbono/farmacologia , Nitrogênio/química , Nitrogênio/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Coroa de Proteína/metabolismo , Pontos Quânticos/química , Pontos Quânticos/metabolismo , Células A549 , Animais , Apirase/química , Apirase/farmacologia , Catalase/química , Catalase/farmacologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Microambiente Celular/efeitos dos fármacos , Enzimas Imobilizadas/química , Enzimas Imobilizadas/farmacologia , Células HeLa , Humanos , Ratos , Espécies Reativas de Oxigênio/metabolismo , beta-Galactosidase/química , beta-Galactosidase/farmacologiaRESUMO
Carbon-based quantum dots are widely suggested as fluorescent carriers of drugs, genes or other bioactive molecules. In this work, we thoroughly examine the easy-to-obtain, biocompatible, nitrogen-containing carbonaceous quantum dots (N-CQDs) with stable fluorescent properties that are resistant to wide-range pH changes. Moreover, we explain the mechanism of fluorescence quenching at extreme pH conditions. Our in vitro results indicate that N-CQDs penetrate the cell membrane; however, fluorescence intensity measured inside the cells was lower than expected from carbonaceous dots extracellular concentration decrease. We studied the mechanism of quenching and identified reduced form of ß-nicotinamide adenine dinucleotide (NADH) as one of the intracellular quenchers. We proved it experimentally that the elucidated redox process triggers the efficient reduction of amide functionalities to non-fluorescent amines on carbonaceous dots surface. We determined the 5 nm-wide reactive redox zone around the N-CQD surface. The better understanding of fluorescence quenching will help to accurately quantify and dose the internalized carbonaceous quantum dots for biomedical applications.
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Graphene oxide (GO) is one of the most exciting and widely used materials. A new method of nanographene oxide (n-GO) formation is presented. The described unique sequence of ultrasonication in dimethyl sulfoxide solution allows us to obtain different sizes of n-GO sheets by controlling the timing of the cutting and re-aggregation processes. The obtained n-GO exhibits only minor spectral changes, mainly due to the formation of S-containing surface groups; thus, it can be concluded that the material is not reduced during the process. Maintaining the initial oxygen functionalities together with the required nano-size (down to 200 nm) and high homogeneity are beneficial for extensive applications of n-GO. Moreover, we prove that the obtained material is evidently biocompatible. The calculated half-maximal effective concentration (EC50) increases by 5-fold, i.e., from 50 to 250 µg/mL, when GO is converted to n-GO. As a consequence, the new n-GO neither disturbs blood flow even in the narrowest capillaries nor triggers a toxic influence in surrounding cells. Thus, it can be a serious candidate for drugs and biomolecule carriers administered systemically.