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1.
Rev. Flum. Odontol. (Online) ; 1(66): 104-122, jan-abr.2025. tab
Artículo en Portugués | LILACS-Express | LILACS | ID: biblio-1570727

RESUMEN

A ansiedade desempenha um papel significativo na experiência de tratamentos odontológicos e pode resultar em evasão por parte dos pacientes. Isso é especialmente relevante para grupos como pacientes pediátricos e aqueles com necessidades especiais, que muitas vezes requerem técnicas de controle de comportamento ou sedação devido à ansiedade. No entanto, a ansiedade não deve ser negligenciada mesmo em pacientes sem odontofobia grave, pois está relacionada à percepção da dor durante os procedimentos odontológicos. A sedação consciente com óxido nitroso surge como uma alternativa valiosa para reduzir a ansiedade e melhorar o conforto do paciente. Ao contrário dos benzodiazepínicos e da anestesia geral, o óxido nitroso atua no sistema nervoso de uma forma que deprime levemente o córtex cerebral, sem afetar o centro respiratório. Isso permite o uso de concentrações subanestésicas do gás, administradas com oxigênio por meio de uma máscara nasal. O óxido nitroso é de rápida ação, pouco solúvel e tem um período de recuperação breve, permitindo que os pacientes retornem rapidamente às atividades normais. Este estudo, uma revisão de literatura, explora o mecanismo de ação do óxido nitroso, suas indicações na prática odontológica e examina possíveis riscos e contraindicações associados ao seu uso. Em resumo, a sedação consciente com óxido nitroso se mostra como uma opção promissora para aliviar a ansiedade e melhorar a experiência de tratamentos odontológicos, beneficiando uma ampla gama de pacientes, não apenas aqueles com fobias graves.


Anxiety, in an outpatient dental environment, plays a fundamental role in pain and discomfort expectation, resulting in increase of treatment evasion. The groups that present greater difficulty in cooperation are children and special needs patients, with behavioral control and sedation being often necessary. Nevertheless, literature emphasizes that anxiety must be evaluated as a critical stage and its management done not only in patients with elevated anxiety levels, but being crucial on pain control of every dental patient, since higher grades of restlessness equals higher pain perception. It is known that the use of nitrous oxide in conscious sedation proves to be an useful tool on reducing anxiety and enabling comfortable interventions, indicating that it is an alternative to the use of benzodiazepines and general anesthesia. The drug acts on the nervous system, promoting a slight depression of the cerebral cortex and, unlike benzodiazepines, which act at the medulla level, it does not depress the respiratory center. The technique uses sub-anesthetic concentrations of nitrous oxide delivered with oxygen through a nasal mask. Nitrous oxide is poorly soluble and has a rapid onset of action, being therefore associated with a rapid recovery period. The duration of sedation is controlled and the patient can quickly return to normal activities. This paper is a narrative review with the objective of exploring the mechanism of action of this gas, evaluating its indications for use in dental clinic and verifying possible risks and contraindications.

2.
J Ethnopharmacol ; 336: 118727, 2025 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-39182700

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Ophiocordyceps sinensis (O. sinensis) is a genus of Ascomycete fungus that is endemic to the alpine meadows of the Tibetan Plateau and adjoining Himalayas. It has been used traditionally as a tonic to improve respiratory health in ancient China as well as to promote vitality and longevity. Bioactive components found in O. sinensis such as adenosine, cordycepin, 3-deoxyadenosine, L-arginine and polysaccharides have gained increasing interest in recent years due to their antioxidative and other properties, which include anti-asthmatic, antiviral, immunomodulation and improvement of general health. AIM OF THE STUDY: This study's primary aim was to investigate the effect of a cultivated fruiting body of O. sinensis strain (OCS02®) on airways patency and the secondary focus was to investigate its effect on the lifespan of Caenorhabditis elegans. MATERIALS AND METHODS: A cultivated strain, OCS02®, was employed and the metabolic profile of its cold-water extract (CWE) was analysed through liquid chromatography-mass spectrometry (LC-MS). Organ bath approach was used to investigate the pharmacological properties of OCS02® CWE when applied on airway tissues obtained from adult male Sprague-Dawley rats. The airway relaxation mechanisms of OCS02® CWE were explored using pharmacological tools, where the key regulators in airway relaxation and constriction were investigated. For the longevity study, age-synchronised, pos-1 RNAi-treated wild-type type Caenorhabditis elegans at the L4 stage were utilised for a lifespan assay. RESULTS: Various glycopeptides and amino acids, particularly a high concentration of L-arginine, were identified from the LC-MS analysis. In airway tissues, OCS02® CWE induced a significantly greater concentration-dependent relaxation when compared to salbutamol. The relaxation response was significantly attenuated in the presence of NG-Nitro-L-arginine methyl ester (L-NAME), 1H-[1,2,4]oxadiazolo [4,3-a]quinoxalin-1-one (ODQ) and several K+ channel blockers. The longevity effect induced by OCS02® CWE (5 mg/mL and above) was observed in C. elegans by at least 17%. CONCLUSIONS: These findings suggest that the airway relaxation mechanisms of OCS02® CWE involved cGMP-dependent and cGMP-independent nitric oxide signalling pathways. This study provides evidence that the cultivated strain of OCS02® exhibits airway relaxation effects which supports the traditional use of its wild O. sinensis in strengthening respiratory health.


Asunto(s)
Cuerpos Fructíferos de los Hongos , Músculo Liso , Ratas Sprague-Dawley , Animales , Masculino , Cuerpos Fructíferos de los Hongos/química , Músculo Liso/efectos de los fármacos , Relajación Muscular/efectos de los fármacos , Ratas , Tráquea/efectos de los fármacos , Tráquea/metabolismo , Longevidad/efectos de los fármacos , Hypocreales
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 324: 124987, 2025 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-39163774

RESUMEN

While numerous methods exist for diagnosing tumors through the detection of miRNA within tumor cells, few can simultaneously achieve both tumor diagnosis and treatment. In this study, a novel graphene oxide (GO)-based DNA nanodevice (DND), initiated by miRNA, was developed for fluorescence signal amplification imaging and photodynamic therapy in tumor cells. After entering the cells, tumor-associated miRNA drives DND to Catalyzed hairpin self-assembly (CHA). The CHA reaction generated a multitude of DNA Y-type structures, resulting in a substantial amplification of Ce6 fluorescence release and the generation of numerous singlet oxygen (1O2) species induced by laser irradiation, consequently inducing cell apoptosis. In solution, DND exhibited high selectivity and sensitivity to miRNA-21, with a detection limit of 11.47 pM. Furthermore, DND discriminated between normal and tumor cells via fluorescence imaging and specifically generated O21 species in tumor cells upon laser irradiation, resulting in tumor cells apoptosis. The DND offer a new approach for the early diagnosis and timely treatment of malignant tumors.


Asunto(s)
ADN , Grafito , MicroARNs , Fotoquimioterapia , Nanomedicina Teranóstica , Fotoquimioterapia/métodos , Humanos , MicroARNs/análisis , Grafito/química , Nanomedicina Teranóstica/métodos , ADN/química , Apoptosis/efectos de los fármacos , Imagen Óptica , Línea Celular Tumoral , Oxígeno Singlete/metabolismo , Oxígeno Singlete/química , Neoplasias/tratamiento farmacológico , Neoplasias/diagnóstico por imagen
4.
J Environ Sci (China) ; 147: 617-629, 2025 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-39003076

RESUMEN

The manganese-cobalt mixed oxide nanorods were fabricated using a hydrothermal method with different metal precursors (KMnO4 and MnSO4·H2O for MnOx and Co(NO3)2⋅6H2O and CoCl2⋅6H2O for Co3O4). Bamboo-like MnO2⋅Co3O4 (B-MnO2⋅Co3O4 (S)) was derived from repeated hydrothermal treatments with Co3O4@MnO2 and MnSO4⋅H2O, whereas Co3O4@MnO2 nanorods were derived from hydrothermal treatment with Co3O4 nanorods and KMnO4. The study shows that manganese oxide was tetragonal, while the cobalt oxide was found to be cubic in the crystalline arrangement. Mn surface ions were present in multiple oxidation states (e.g., Mn4+ and Mn3+) and surface oxygen deficiencies. The content of adsorbed oxygen species and reducibility at low temperature declined in the sequence of B-MnO2⋅Co3O4 (S) > Co3O4@MnO2 > MnO2 > Co3O4, matching the changing trend in activity. Among all the samples, B-MnO2⋅Co3O4 (S) showed the preeminent catalytic performance for the oxidation of toluene (T10% = 187°C, T50% = 276°C, and T90% = 339°C). In addition, the B-MnO2⋅Co3O4 (S) sample also exhibited good H2O-, CO2-, and SO2-resistant performance. The good catalytic performance of B-MnO2⋅Co3O4 (S) is due to the high concentration of adsorbed oxygen species and good reducibility at low temperature. Toluene oxidation over B-MnO2⋅Co3O4 (S) proceeds through the adsorption of O2 and toluene to form O*, OH*, and H2C(C6H5)* species, which then react to produce benzyl alcohol, benzoic acid, and benzaldehyde, ultimately converting to CO2 and H2O. The findings suggest that B-MnO2⋅Co3O4 (S) has promising potential for use as an effective catalyst in practical applications.


Asunto(s)
Cobalto , Compuestos de Manganeso , Oxidación-Reducción , Óxidos , Tolueno , Óxidos/química , Compuestos de Manganeso/química , Catálisis , Cobalto/química , Tolueno/química , Contaminantes Atmosféricos/química
5.
J Environ Sci (China) ; 148: 139-150, 2025 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-39095153

RESUMEN

Herein, a modified screen printed carbon electrode (SPCE) based on a composite material, graphene oxide-gold nanoparticles (GO-AuNPs), and poly(3-aminobenzoic acid)(P3ABA) for the detection of paraquat (PQ) is introduced. The modified electrode was fabricated by drop casting of the GO-AuNPs, followed by electropolymerization of 3-aminobenzoic acid to achieve SPCE/GO-AuNPs/P3ABA. The morphology and microstructural characteristics of the modified electrodes were revealed by scanning electron microscopy (SEM) for each step of modification. The composite GO-AuNPs can provide high surface area and enhance electroconductivity of the electrode. In addition, the presence of negatively charged P3ABA notably improved PQ adsorption and electron transfer rate, which stimulate redox reaction on the modified electrode, thus improving the sensitivity of PQ analysis. The SPCE/GO-AuNPs/P3ABA offered a wide linear range of PQ determination (10-9-10-4 mol/L) and low limit of detection (LOD) of 0.45 × 10-9 mol/L or 0.116 µg/L, which is far below international safety regulations. The modified electrode showed minimum interference effect with percent recovery ranging from 96.5% to 116.1% after addition of other herbicides, pesticides, metal ions, and additives. The stability of the SPCE/GO-AuNPs/P3ABA was evaluated, and the results indicated negligible changes in the detection signal over 9 weeks. Moreover, this modified electrode was successfully implemented for PQ analysis in both natural and tapped water with high accuracy.


Asunto(s)
Técnicas Electroquímicas , Electrodos , Oro , Grafito , Nanopartículas del Metal , Paraquat , Grafito/química , Paraquat/análisis , Oro/química , Nanopartículas del Metal/química , Técnicas Electroquímicas/métodos , Límite de Detección , Carbono/química , Contaminantes Químicos del Agua/análisis , Herbicidas/análisis
6.
J Environ Sci (China) ; 148: 637-649, 2025 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-39095196

RESUMEN

In this study, we investigated improving the performance of a layered double hydroxide (LDH) for the adsorption of As(III) and As(V) by controlling the morphology of LDH crystals. The LDH was synthesized via a simple coprecipitation method using barely soluble MgO as a precursor and succinic acid (SA) as a morphological control agent. Doping the LDH crystals with carboxylate ions (RCOO-) derived from SA caused the crystals to develop in a radial direction. This changed the pore characteristics and increased the density of active surface sites. Subsequently, SA/MgFe-LDH showed excellent affinity for As(III) and As(V) with maximum sorption densities of 2.42 and 1.60 mmol/g, respectively. By comparison, the pristine MgFe-LDH had sorption capacities of 1.56 and 1.31 mmol/g for As(III) and As(V), respectively. The LDH was effective over a wide pH range for As(III) adsorption (pH 3-8.5) and As(V) adsorption (pH 3-6.5). Using a combination of spectroscopy and sorption modeling calculations, the main sorption mechanism of As(III) and As(V) on SA/MgFe-LDH was identified as inner-sphere complexation via ligand exchange with hydroxyl group (-OH) and RCOO-. Specifically, bidentate As-Fe complexes were proposed for both As(III) and As(V) uptake, with the magnitude of formation varying with the initial As concentration. Importantly, the As-laden adsorbent had satisfactory stability in simulated real landfill leachate. These findings demonstrate that SA/MgFe-LDH exhibits considerable potential for remediation of As-contaminated water.


Asunto(s)
Arsénico , Hidróxidos , Óxido de Magnesio , Ácido Succínico , Contaminantes Químicos del Agua , Adsorción , Contaminantes Químicos del Agua/química , Cinética , Arsénico/química , Ácido Succínico/química , Hidróxidos/química , Óxido de Magnesio/química , Purificación del Agua/métodos , Modelos Químicos
7.
J Environ Sci (China) ; 149: 149-163, 2025 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-39181630

RESUMEN

Developing heterojunction photocatalyst with well-matched interfaces and multiple charge transfer paths is vital to boost carrier separation efficiency for photocatalytic antibiotics removal, but still remains a great challenge. In present work, a new strategy of chloride anion intercalation in Bi2O3 via one-pot hydrothermal process is proposed. The as-prepared Ta-BiOCl/Bi24O31Cl10 (TBB) heterojunctions are featured with Ta-Bi24O31Cl10 and Ta-BiOCl lined shoulder-by-shouleder via semi-coherent interfaces. In this TBB heterojunctions, the well-matched semi-coherent interfaces and shoulder-by-shoulder structures provide fast electron transfer and multiple transfer paths, respectively, leading to enhanced visible light response and improved photogenerated charge separation. Meanwhile, a type-II heterojunction for photocharge separation has been obtained, in which photogenerated electrons are drove from the CB (conduction band) of Ta-Bi24O31Cl10 to the both of bilateral empty CB of Ta-BiOCl and gathered on the CB of Ta-BiOCl, while the photogenerated holes are left on the VB (valence band) of Ta-Bi24O31Cl10, effectively hindering the recombination of photogenerated electron-hole pairs. Furthermore, the separated electrons can effectively activate dissolved oxygen for the generation of reactive oxygen species (·O2-). Such TBB heterojunctions exhibit remarkably superior photocatalytic degradation activity for tetracycline hydrochloride (TCH) solution to Bi2O3, Ta-BiOCl and Ta-Bi24O31Cl10. This work not only proposes a Ta-BiOCl/Bi24O31Cl10 shoulder-by-shoulder micro-ribbon architectures with semi-coherent interfaces and successive type-II heterojunction for highly efficient photocatalytic activity, but offers a new insight into the design of highly efficient heterojunction through phase-structure synergistic transformation strategy.


Asunto(s)
Antibacterianos , Bismuto , Contaminantes Químicos del Agua , Bismuto/química , Antibacterianos/química , Contaminantes Químicos del Agua/química , Catálisis , Procesos Fotoquímicos
8.
J Environ Sci (China) ; 149: 488-499, 2025 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-39181661

RESUMEN

Eutrophic shallow lakes are generally considered as a contributor to the emission of nitrous oxide (N2O), while regional and global estimates have remained imprecise. This due to a lack of data and insufficient understanding of the multiple contributing factors. This study characterized the spatiotemporal variability in N2O concentrations and N2O diffusive fluxes and the contributing factors in Lake Wuliangsuhai, a typical shallow eutrophic and seasonally frozen lake in Inner Mongolia with cold and arid climate. Dissolved N2O concentrations of the lake exhibited a range of 4.5 to 101.2 nmol/L, displaying significant spatiotemporal variations. The lowest and highest concentrations were measured in summer and winter, respectively. The spatial distribution of N2O flux was consistent with that of N2O concentrations. Additionally, the hotspots of N2O emissions were detected within close to the main inflow of lake. The wide spatial and temporal variation in N2O emissions indicate the complexity and its relative importance of factors influencing emissions. N2O emissions in different lake zones and seasons were regulated by diverse factors. Factors influencing the spatial and temporal distribution of N2O concentrations and fluxes were identified as WT, WD, DO, Chl-a, SD and COD. Interestingly, the same factor demonstrated opposing effects on N2O emission in various seasons or zones. This research improves our understanding of N2O emissions in shallow eutrophic lakes in cold and arid areas.


Asunto(s)
Monitoreo del Ambiente , Lagos , Óxido Nitroso , Estaciones del Año , Óxido Nitroso/análisis , Lagos/química , China , Contaminantes Atmosféricos/análisis , Eutrofización , Análisis Espacio-Temporal , Contaminantes Químicos del Agua/análisis
9.
Biomaterials ; 312: 122743, 2025 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-39111233

RESUMEN

Photodynamic therapy (PDT) is an appealing modality for cancer treatments. However, the limited tissue penetration depth of external-excitation light makes PDT impossible in treating deep-seated tumors. Meanwhile, tumor hypoxia and intracellular reductive microenvironment restrain the generation of reactive oxygen species (ROS). To overcome these limitations, a tumor-targeted self-illuminating supramolecular nanoparticle T-NPCe6-L-N is proposed by integrating photosensitizer Ce6 with luminol and nitric oxide (NO) for chemiluminescence resonance energy transfer (CRET)-activated PDT. The high H2O2 level in tumor can trigger chemiluminescence of luminol to realize CRET-activated PDT without exposure of external light. Meanwhile, the released NO significantly relieves tumor hypoxia via vascular normalization and reduces intracellular reductive GSH level, further enhancing ROS abundance. Importantly, due to the different ROS levels between cancer cells and normal cells, T-NPCe6-L-N can selectively trigger PDT in cancer cells while sparing normal cells, which ensured low side effect. The combination of CRET-based photosensitizer-activation and tumor microenvironment modulation overcomes the innate challenges of conventional PDT, demonstrating efficient inhibition of orthotopic and metastatic tumors on mice. It also provoked potent immunogenic cell death to ensure long-term suppression effects. The proof-of-concept research proved as a new strategy to solve the dilemma of PDT in treatment of deep-seated tumors.


Asunto(s)
Nanopartículas , Fotoquimioterapia , Fármacos Fotosensibilizantes , Microambiente Tumoral , Fotoquimioterapia/métodos , Microambiente Tumoral/efectos de los fármacos , Animales , Nanopartículas/química , Fármacos Fotosensibilizantes/uso terapéutico , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/farmacología , Humanos , Ratones , Línea Celular Tumoral , Especies Reactivas de Oxígeno/metabolismo , Transferencia de Energía , Neoplasias/tratamiento farmacológico , Neoplasias/terapia , Ratones Endogámicos BALB C , Luz , Ratones Desnudos , Óxido Nítrico/metabolismo
10.
Int Immunopharmacol ; 142(Pt B): 113173, 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39298816

RESUMEN

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide, with the gut microbiota and its metabolites are important regulators of its progression. Trimethylamine N-oxide (TMAO), a metabolite of the gut microbiota, has been closely associated with various metabolic diseases, but its relationship with NAFLD remains to be elucidated. In this study, we found that fecal TMAO levels correlated with NAFLD severity. Moreover, TMAO promoted lipid deposition in HepG2 fatty liver cells and exacerbated hepatic steatosis in NAFLD rats. In the colon, TMAO undermined the structure and function of the intestinal barrier at various levels, further activated the TLR4/MyD88/NF-κB pathway, and inhibited the WNT/ß-catenin pathway. In the liver, TMAO induced endothelial dysfunction with capillarization of liver sinusoidal endothelial cells, while modulating macrophage polarization. In conclusion, our study suggests that gut microbiota metabolite TMAO promotes NAFLD progression by impairing the gut and liver and that targeting TMAO could be an alternative therapeutic strategy for NAFLD.

11.
J Colloid Interface Sci ; 678(Pt C): 309-316, 2024 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-39298983

RESUMEN

Carbon dioxide electroreduction is a green technology for artificial carbon sequestration, which is being delayed from industrialization due to the lack of efficient catalysts at high current conditions. Herein, the Bi2O3 nanoflakes were uniformly grown on a defective porous carbon (PC). This self-assembling Bi2O3/PC catalyst was applied to drive CO2 electroreduction at 1.0 A, 1.5 A and 2.0 A while the Faradaic efficiency of formate reaches 91.50 %, 86.30 % and 84.22 %, respectively. Density functional theory calculations revealed the intrinsic defect of carbon is able to give electron to Bi through O bridge, which increased the electron aggregation of Bi and lowered the generation energy barrier of *OCHO intermediate. Additionally, the unique 3D network of staggered Bi2O3 enhances the CO2 adsorption and favors the electron transportation. By integrating all above advantages into a solid electrolyte-type cell, we are able to produce pure formic acid in a rate of 15.48 mmol h-1 at ampere current.

12.
Ecotoxicol Environ Saf ; 285: 117032, 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39299214

RESUMEN

Contamination of aquatic food webs with nanomaterials poses a significant ecological and human health challenge. Ingestion of nanomaterials alongside food disrupts digestion and impairs physiological processes, with potential consequences for organism fitness and survival. Complex interactions between nanomaterials and biota further exacerbate the issue, influencing life-history strategies and ecosystem dynamics. Accumulation of nanomaterials within autotrophic and detritus-based food webs raises concerns about biomagnification, especially for top-level consumers and seafood-dependent human populations. Understanding the extent and impact of nanomaterial contamination on aquatic biota is crucial for effective mitigation strategies. To address this challenge, we conducted a comprehensive study evaluating the bioaccumulation effects of graphene oxide (GO), a commonly used nanomaterial, within an aquatic food chain. Using a gnotobiotic freshwater microcosm, we investigated the effects of micro- and nano-scale GO sheets on key organisms: green algae (Chlorella vulgaris), brine shrimp (Artemia salina), and zebrafish (Danio rerio). Two feeding regimes, direct ingestion and trophic transfer, were employed to assess GO uptake and transfer within the food web. Direct exposure involved individual organisms being exposed to either nano- or micro-scale GO sheets, while trophic transfer involved a sequential exposure pathway: algae exposed to GO sheets, artemias feeding on the algae, and zebrafish consuming the artemias. Our study provides critical insights into nanomaterial contamination in aquatic ecosystems. Physicochemical properties of GO sheets, including ζ-potential and dispersion, were influenced by salt culture media, resulting in aggregation under salt conditions. Microscopic imaging confirmed the bioaccumulation of GO sheets within organisms, indicating prolonged exposure and potential long-term effects. Notably, biodistribution analysis in zebrafish demonstrated the penetration of nano-sized GO into the intestinal wall, signifying direct interaction with vital organs. Exposure to GO resulted in increased zebrafish mortality and impaired reproductive performance, particularly through trophic transfer. These findings emphasize the urgent need to address nanomaterial contamination in aquatic food webs to protect ecosystem components and human consumers. Our study highlights the importance of developing effective mitigation strategies to preserve the integrity of aquatic ecosystems, ensure resource sustainability, and safeguard human well-being. In conclusion, our study provides crucial insights into the impact of nanomaterial pollution on aquatic biota. By recognizing the challenges posed by nanomaterial contamination and implementing targeted interventions, we can mitigate the adverse effects, preserving the integrity of aquatic ecosystems and safeguarding human health.

13.
Protein Expr Purif ; : 106609, 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39299600

RESUMEN

The recognition and characterization of gene-encoded nitric oxide synthase (NOS) from Exiguobacterium profundum are reported in this study. A new gene was sequenced and cloned from E. profundum and heterologously expressed in E. coli for functional identification, followed by protein purification using the His-tag. The stability and activity characteristics of the recombinant NOS were evaluated using different concentrations of IPTG at various time points. A band of approximately 42 kDa was observed by SDS-PAGE. The Km value of NOS, calculated based on the Michaelis-Menten equation, was 0.59 µmol/L. Additionally, homologous sequence alignment analysis indicated that the new NOS shared 80.48% similarity with the same protein from Bacillus subtilis and Umezawaea. The construction of the NOS expression vector and the purification of the recombinant protein provide a foundation for further functional research and inhibitor development.

14.
Acta Biomater ; 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39299622

RESUMEN

Biofilm infection and impaired healing of chronic wounds are posing tremendous challenges in clinical practice. In this study, we presented a versatile antimicrobial hydrogel capable of delivering nitric oxide (NO) in a controllable manner to dissipate biofilms, eliminate microorganisms, and promote the healing of chronic wounds. This hydrogel was constructed by Schiff-base crosslinking of oxidized dextran and antimicrobial peptide ε-poly-lysine, further encapsulating photothermal nanoparticles bearing NO donor. This hydrogel could continuously and slowly release NO, effectively dissipating biofilms, and promoting the proliferation of mouse fibroblasts and the migration of endothelial cells. Upon exposure to NIR laser irradiation, the hydrogel generated hyperthermia and rapidly released NO, resulting in the efficient elimination of a broad spectrum of drug-resistant Gram-positive/negative bacterial and fungal biofilms through the synergistic effects of NO, photothermal therapy, and the antibacterial peptide. Notably, the hydrogel demonstrated exceptional in vivo therapeutic outcomes in accelerating the healing process of mice diabetic wounds infected with methicillin-resistant Staphylococcus aureus by successfully eliminating biofilm infection, regulating inflammation, and facilitating angiogenesis and collagen deposition. Overall, this proposed hydrogel shows great promise in accommodating the various demands of the complex repair process of chronic wounds infected with biofilms. STATEMENT OF SIGNIFICANCE: : The presence of biofilm infections and underlying dysfunctions in the healing process made chronic wound become stuck in the inflammation stage and difficult to heal. This work developed a NIR laser-modulated three-stage NO-releasing versatile antimicrobial hydrogel (DEPN) exhibiting good therapeutic efficacy for chronic wound. This DEPN hydrogel could inherently and slowly released NO to disperse biofilm. Upon NIR laser irradiation, the DEPN hydrogel generated hyperthermia and induced a rapid burst release of NO effectively eliminating a broad spectrum of drug-resistant bacterial and fungal biofilms. Subsequently, the DEPN hydrogel continually release NO slowly to promote the tissue remolding. This DEPN hydrogel displays great potential in treatment of chronic wounds infected with biofilm.

15.
Bone ; : 117257, 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39299627

RESUMEN

Bone is influenced by many factors such as genetics and mechanical loading, but the short-term physiological effects of these factors on bone (re)modelling are not well characterised. This study investigated the effects of endurance trainability phenotype, sex, and interval running training (7-week intervention) on bone collagen formation in rats using a deuterium oxide stable isotope tracer method. Bone samples of the femur diaphysis, proximal tibia, mid-shaft tibia, and distal tibia were collected after necropsy from forty-six 9 ±â€¯3-month male and female rats selectively bred for yielding low (LRT) or high (HRT) responses to endurance training. Bone collagen proteins were isolated and hydrolysed, and fractional synthetic rates (FSRs) were determined by the incorporation of deuterium into protein-bound alanine via GC-pyrolysis-IRMS. There was a significant large main effect of phenotype at the femur site (p < 0.001; η2g = 0.473) with HRT rats showing greater bone collagen FSRs than LRT rats. There was a significant large main effect of phenotype (p = 0.008; η2g = 0.178) and a significant large main effect of sex (p = 0.005; η2g = 0.196) at the proximal site of the tibia with HRT rats showing greater bone collagen FSRs than LRT rats, and male rats showing greater bone collagen FSRs compared to female rats. There was a significant large main effect of training at the mid-shaft site of the tibia (p = 0.012; η2g = 0.159), with rats that underwent interval running training having greater bone collagen FSRs than control rats. Similarly, there was a significant large main effect of training at the distal site of the tibia (p = 0.050; η2g = 0.156), with rats in the interval running training group having greater bone collagen FSRs compared to rats in the control group. Collectively, this evidence highlights that bone responses to physiological effects are site-specific, indicating that interval running training has positive effects on bone collagen synthesis at the tibial mid-shaft and distal sites, whilst genetic factors affect bone collagen synthesis at the femur diaphysis (phenotype) and proximal tibia (phenotype and sex) in rats.

16.
Nitric Oxide ; 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39299646

RESUMEN

The biochemical interplay between antioxidants and pro-oxidants maintains the redox homeostatic balance of the cell, which, when perturbed to moderate or high extents, has been implicated in the onset and/or progression of chronic diseases such as diabetes mellitus, cancer, and neurodegenerative diseases. Thioredoxin, glutaredoxin, and lipoic acid-like thiol oxidoreductase systems constitute a unique ensemble of robust cellular antioxidant defenses, owing to their indispensable roles as S-denitrosylases, S-deglutathionylases, and disulfide reductants in maintaining a reduced free thiol state with biological relevance. Thus, in cells subjected to nitrosative stress, cellular antioxidants will S-denitrosylate their cognate S-nitrosoprotein substrates, rather than participate in trans-S-nitrosation via protein-protein interactions. Researchers have been at the forefront of vaguely establishing the concept of 'transnitrosylation' and its influence on pathophysiology with experimental evidence from in vitro studies that lack proper biochemical logic. The suggestive and reiterative use of antioxidants as transnitrosylases in the scientific literature leaves us on a cliffhanger with several open-ended questions that prompted us to 'hunt' for scientific logic behind the trans-S-nitrosation chemistry. Given the gravity of the situation and to look at the bigger picture of 'trans-S-nitrosylation', we aim to present a novel attempt at justifying the hesitance in accepting antioxidants as capable of transnitrosylating their cognate protein partners and reflecting on the need to resolve the controversy that would be crucial from the perspective of understanding therapeutic outcomes involving such cellular antioxidants in disease pathogenesis. Further characterization is required to identify the regulatory mechanisms or conditions where an antioxidant like Trx, Grx, or DJ-1 can act as a cellular transnitrosylase.

17.
Nitric Oxide ; 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39299647

RESUMEN

Nitric oxide (NO) plays a crucial role as a messenger or effector in the body, yet it presents a dual impact on cardio-cerebrovascular health. Under normal physiological conditions, NO exhibits vasodilatory effects, regulates blood pressure, inhibits platelet aggregation, and offers neuroprotective actions. However, in pathological situations, excessive NO production contributes to or worsens inflammation within the body. Moreover, NO may combine with reactive oxygen species (ROS), generating harmful substances that intensify physical harm. This paper succinctly reviews pertinent literature to clarify the in vivo and in vitro origins of NO, its regulatory function in the cardio-cerebrovascular system, and the advantages and disadvantages associated with NO donor drugs, NO delivery systems, and vascular stent materials for treating cardio-cerebrovascular disease. The findings provide a theoretical foundation for the application of NO in cardio-cerebrovascular diseases.

18.
Angew Chem Int Ed Engl ; : e202411618, 2024 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-39299916

RESUMEN

High-voltage P2-Na0.67Ni0.33Mn0.67O2 layered oxide cathode exhibits significant potential for sodium-ion batteries, owing to the elevated operating voltage and theoretical energy density beyond lithium iron phosphate, but the large-volume phase transition is the devil. Currently, this type cathode still suffers from stability-capacity trade-off dilemma. Herein, a concept of customized strategy via multiple rock-forming elements trace doping is presented to address the mentioned issue. The customized Mg-Al-Ti trace doped cathode maintains a notable capacity of 140.3 mAh g - 1 with an energy density approaching 500 Wh kg - 1, and shows good cycle stability, retaining 89.0% of its capacity after 50 cycles at 0.1C. Additionally, the full cell, paired with a hard carbon anode, achieves an advanced energy density of 303.3 Wh kg-1. The multiple characterizations reveal the failure mechanism of contrast sample involving severe intragranular cracks coupled with layer to rock salt transformation, which reduces active substance and increases charge transfer resistance. The doped sample with increased sliding energy barrier well suppresses this phenomenon. Impressively, the customized strategy can be extended to Mg-Fe-Ti system. This research provides a novel concept for the design of high energy sodium-ion cathode.

19.
BMC Chem ; 18(1): 181, 2024 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-39300584

RESUMEN

BACKGROUND: superparamagnetic ferroferric oxide (Fe3O4) nanoparticles can be extensively functionalized for applications in drug enrichment and separation. Their high magnetic responsiveness and controllable surface modification enable rapid drug enrichment and separation under external magnetic fields. This study aimed to enhance the application potential of superparamagnetic Fe3O4 nanoparticles in the field of drug enrichment and separation by functionalizing these nanoparticles to improve their biocompatibility and targeting capabilities. METHODS: superparamagnetic Fe3O4 nanoparticles functionalized with dopamine were synthesized using benzyl alcohol as the solvent and iron acetylacetonate as the precursor. The dopamine-functionalized superparamagnetic iron oxide nanoparticles were used to analyze protein enrichment and separation. Characterization of the nanoparticles was conducted, including analysis of particle size distribution, Zeta potential, and fluorescence spectra using a fluorescence spectrophotometer. RESULTS: the Fe3O4 nanoparticles maintained high magnetism from the original material and exhibited uniform particle size distribution and stable Zeta potential. The saturation magnetization of dopamine-functionalized superparamagnetic Fe3O4 nanoparticles showed no significant difference compared to before coating, indicating minimal influence of dopamine on the internal magnetic core of the nanoparticles. The Fe3O4 nanoparticles demonstrated good biocompatibility and stability. CONCLUSION: functionalization of superparamagnetic Fe3O4 nanoparticles significantly enhances their efficiency in drug enrichment and separation processes, suggesting broad applications in the pharmaceutical industry.

20.
Artículo en Inglés | MEDLINE | ID: mdl-39300615

RESUMEN

Passive daytime radiative cooling (PDRC) textiles hold substantial potential for localized outdoor cooling of the human body without additional energy consumption, but their limited multifunctional integration severely hinders their practical application. Herein, aluminum-doped zinc oxide (AZO) nanoparticles were purposefully introduced into poly(vinylidene fluoride) (PVDF) nanofibers via a facile electrospinning process, forming a large-scale and flexible PDRC textile with the desired antibacterial, UV-shielding, and self-cleaning capabilities. These prepared PDRC textiles present a weighted sunlight reflection rate of 92.3% and a weighted emissivity of 89.5% in the mid-infrared region. Furthermore, outdoor tests with an average solar intensity of ∼715 W/m2 demonstrated that a skin simulator temperature could be cooled by ∼16.1 °C below the ambient temperature, outperforming cotton fabric by ∼6.3 °C. Owing to the outstanding photocatalytic properties of the AZO nanoparticles, these prepared PVDF textiles exhibit antibacterial properties (Escherichia coli: 99.99%), UV-shielding performance (UPF > 50+), and superior self-cleaning capabilities, providing a cost-effective and eco-friendly avenue for daytime personal thermal management.

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