RESUMEN

In this study, the interaction of the human hemoglobin with cost effective and chemically fabricated CdS quantum dots (QDs) (average sizes ≈3nm) has been investigated. The semiconductor QDs showed maximum visible absorption at 445 nm with excitonic formation and band gap of ≈ 2.88 eV along with hexagonal crystalline phase. The binding of QDs-Hb occurs through corona formation to the ground sate complex formation. The life time of the heme pocket binding and reorganization were found to be t1 = 43 min and t2 = 642 min, respectively. The emission quenching of the Hb has been indicated large energy transfer between CdS QDs and Hb with tertiary deformation of Hb. The binding thermodynamics showed highly exothermic nature. The ultrafast decay during corona formation was studied from TCSPC. The results showed that the energy transfer efficiency increases with the increase of the QDs concentration and maximum ≈71.5 % energy transfer occurs and average ultrafast lifetime varies from 5.45 ns to1.51 ns. The deformation and unfolding of the secondary structure of Hb with changes of the α-helix (≈74 % to ≈51.07 %) and ß-sheets (≈8.63 % to ≈10.25 %) have been observed from circular dichroism spectrum. The SAXS spectrum showed that the radius of gyration of CdS QDs-Hb bioconjugate increased (up to 23 ± 0.45 nm) with the increase of the concentration of QDs compare with pure Hb (11 ± 0.23 nm) and Hb becoming more unfolded.

Asunto(s)

Compuestos de Cadmio , Transferencia de Energía , Hemoglobinas , Desplegamiento Proteico , Puntos Cuánticos , Sulfuros , Puntos Cuánticos/química , Humanos , Compuestos de Cadmio/química , Sulfuros/química , Sulfuros/metabolismo , Hemoglobinas/química , Hemoglobinas/metabolismo , Unión Proteica , Termodinámica , Espectrometría de Fluorescencia , Dicroismo Circular

RESUMEN

The capped CdS-ZnS quantum dots (QDs) were synthesized with various thiol capping agents of glycolic acid (TGA), mercaptosuccinic acid (MSA), and L-cysteine (LCY) and used as fluorescence probe for determination of Cu (II) ions. The method of two-level three-factor full-factorial experiment design was used to achieve the best optical fluorescence emission. Results revealed that Cu (II) ions can effectively quench the emission of QDs, and the fluorescence intensity is linearly decreased with increasing Cu (II) ion concentration. The limit of detection for CdS-ZnS@ QDs capped with TGA, MSA, and LCY was obtained at 1.15 × 10-7, 1.32 × 10-7, and 2.19 × 10-7 mol L-1, respectively, with linear dynamic range of 3.13 × 10-6 to 1.41 × 10-4 mol L-1. Luminescence quantum yields of CdS-ZnS@LCY, CdS-ZnS@MSA, and CdS-ZnS@TGA were obtained at 4.17, 1.92, and 2.47, respectively. Results indicated that no significant quenching occurred in the presence of the other metal ions. The binding constant (Kb) of capped CdS-ZnS@ QDs with Cu2+ and the other metal ions was also investigated and discussed. The Kb value for Cu2+ was obtained considerably more than that the other ions. This work presents a new and sensitive method for determination of Cu2+ ion.

Asunto(s)

Compuestos de Cadmio , Cobre , Colorantes Fluorescentes , Puntos Cuánticos , Compuestos de Sulfhidrilo , Sulfuros , Propiedades de Superficie , Compuestos de Zinc , Puntos Cuánticos/química , Cobre/química , Cobre/análisis , Sulfuros/química , Compuestos de Zinc/química , Compuestos de Cadmio/química , Compuestos de Sulfhidrilo/química , Compuestos de Sulfhidrilo/análisis , Colorantes Fluorescentes/química , Colorantes Fluorescentes/síntesis química , Espectrometría de Fluorescencia , Fluorescencia , Iones/química , Iones/análisis

RESUMEN

Mechanochemical synthesis is an extremely useful strategy to reach thermoelectric materials due to its solvent-free one-step character, as the targeted thermoelectricity (TE) materials in a nanocrystalline format can be prepared by mere high-energy milling of elemental precursors. Nevertheless, the subsequent densification method (e.g., spark plasma sintering or hot pressing) is required afterward, similarly to other synthetic methodologies. In this study, the simplicity of mechanochemical synthesis is presented for two selected metal chalcogenides, namely copper sulfide (Cu1.8S, digenite) and tin selenide (SnSe, svetlanaite), which are known for high ZT values. These compounds can be prepared via a mechanically induced self-propagating reaction (MSR), which is a combustion-like process instantly yielding the products in a very short timeframe (within 1 min). The occurrence of MSR can be well-tracked by in situ temperature monitoring since an abrupt temperature increase occurs at the moment of MSR. We have developed a device which is capable of monitoring the temperature inside the milling jar every 80 ms during planetary ball milling, and it is therefore possible to very precisely track the moment of MSR ignition. The developed device presents an improvement in the monitoring capabilities in comparison with commercially available analogs. This contribution aims to provide a visual insight into all steps, with simple high-energy ball milling of elements to reach TE materials and in situ temperature monitoring being the central points.

Asunto(s)

Cobre , Cobre/química , Calcógenos/química , Sulfuros/química , Sulfuros/síntesis química , Temperatura

RESUMEN

The common housefly, Musca domestica, known for transmitting over 100 infections, was studied using green-synthesized Cadmium Sulfide nanoparticles (CdS NPs) from Agaricus bisporus. These CdS NPs were tested on third-instar larvae under laboratory conditions using dipping and feeding methods with concentrations (75, 100, 125, 150, 175, and 200 µg/mL). The toxicity, measured by LC50, was found to be 138 µg/mL for dipping treatment and 123 µg/mL for feeding treatment. Analysis with an energy-dispersive X-ray microanalyzer confirmed Cd accumulation in the larval midgut, indicating penetration of CdS NPs into the organism, which may potentially increase their toxicity. CdS NPs caused disruptions in Heat Shock Protein 70, cell apoptosis, and various biochemical components. Scanning electron microscopy revealed morphological abnormalities in larvae, pupae, and adults exposed to CdS NPs. Ultrastructural examination showed significant midgut tissue abnormalities in larvae treated with 123 µg/mL of CdS NPs. Our study demonstrated that green-synthesized CdS NPs from A. bisporus can effectively control the development of M. domestica larvae.

Asunto(s)

Agaricus , Compuestos de Cadmio , Moscas Domésticas , Larva , Sulfuros , Animales , Moscas Domésticas/efectos de los fármacos , Sulfuros/química , Sulfuros/farmacología , Compuestos de Cadmio/toxicidad , Larva/efectos de los fármacos , Nanopartículas del Metal/química , Nanopartículas del Metal/toxicidad , Nanopartículas/química , Modelos Biológicos

RESUMEN

Flexible technology in sensors have received much attention in monitoring of human health through various physiological indicators. Thus, it drawn a lot of interest in the development of flexible substrate for the diagnosis of various diseases via analysis of analytes. Present work focusses on the development of ecofriendly, portable, flexible, conducting thread (Th) and used as smart substrate for fabrication of biosensor towards ultrasensitive detection of the lung cancer biomarker (cytoskeleton-associated protein 4; CKAP4). The zirconium trisulfide-reduced graphene oxide nanocomposite and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) modified cotton thread based biosensor was fabricated via dip coating method. Next, successive immobilization of monoclonal antibodies of CKAP4 (anti-CKAP4) and bovine serum albumin (BSA) was performed via drop cast approach using fabricated electrode [nZrS3@rGO/PEDOT:PSS/Th]. The response of fabricated electrode (BSA/anti-CKAP4/ZrS3@rGO/PEDOT:PSS/Th) was recorded electrochemically versus CKAP4 concentration via chronoamperometry (CA). The results showed wider linear detection range of 6.25-800 pg mL-1, excellent sensitivity of 85.2 µA[log(pg mL-1)]-1cm-2 with good stability up to 42 days. The response of fabricated biosensor was supported by investigating response of CKAP4 biomarker present in patients of lung cancer (concentration as determined through enzyme-linked immunosorbent assay) and obtained results exhibited excellent correlation with that of standard samples.

Asunto(s)

Técnicas Biosensibles , Técnicas Electroquímicas , Grafito , Neoplasias Pulmonares , Circonio , Grafito/química , Técnicas Biosensibles/métodos , Circonio/química , Humanos , Neoplasias Pulmonares/diagnóstico , Técnicas Electroquímicas/métodos , Límite de Detección , Sulfuros/química , Biomarcadores de Tumor/análisis , Oxidación-Reducción , Electrodos , Albúmina Sérica Bovina/química

RESUMEN

BACKGROUND: Rare-earth sulfide nanoparticles (NPs) could harness the optical and magnetic features of rare-earth ions for applications in nanotechnology. However, reports of their synthesis are scarce and typically require high temperatures and long synthesis times. RESULTS: Here we present a biosynthesis of terbium sulfide (TbS) NPs using microorganisms, identifying conditions that allow Escherichia coli to extracellularly produce TbS NPs in aqueous media at 37 °C by controlling cellular sulfur metabolism to produce a high concentration of sulfide ions. Electron microscopy revealed ultrasmall spherical NPs with a mean diameter of 4.1 ± 1.3 nm. Electron diffraction indicated a high degree of crystallinity, while elemental mapping confirmed colocalization of terbium and sulfur. The NPs exhibit characteristic absorbance and luminescence of terbium, with downshifting quantum yield (QY) reaching 28.3% and an emission lifetime of ~ 2 ms. CONCLUSIONS: This high QY and long emission lifetime is unusual in a neat rare-earth compound; it is typically associated with rare-earth ions doped into another crystalline lattice to avoid non-radiative cross relaxation. This suggests a reduced role of nonradiative processes in these terbium-based NPs. This is, to our knowledge, the first report revealing the advantage of biosynthesis over chemical synthesis for Rare Earth Element (REE) based NPs, opening routes to new REE-based nanocrystals.

Asunto(s)

Escherichia coli , Metales de Tierras Raras , Sulfuros , Terbio , Terbio/química , Terbio/metabolismo , Escherichia coli/metabolismo , Sulfuros/metabolismo , Sulfuros/química , Metales de Tierras Raras/metabolismo , Metales de Tierras Raras/química , Nanopartículas/química , Luminiscencia , Tecnología Química Verde/métodos

RESUMEN

Background and Purpose: Growth hormone-releasing hormone (GHRH) agonist, a 29-amino acid peptide, shows significant potential in treating myocardial infarction (MI) by aiding the repair of injured heart tissue. The challenge lies in the effective on-site delivery of GHRH agonist. This study explores the use of a targetable delivery system employing ROS-responsive PEG-PPS-PEG polymers to encapsulate and deliver GHRH agonist MR409 for enhanced therapeutic efficacy. Methods: We synthesized a self-assembling poly (ethylene glycol)-poly (propylene sulfide)-poly (ethylene glycol) polymer (PEG-PPS-PEG) amphiphilic polymer responsive to reactive oxygen species (ROS). The hydrophilic peptide GHRH agonist MR409 was encapsulated within these polymers to form nano PEG-PPS-PEG@MR409 vesicles (NPs). Cardiomyocyte apoptosis was induced under hypoxia and serum-free culture condition for 24 hours, and their production of ROS was detected by fluorescence dye staining. The cellular uptake of PEG-PPS-PEG@MR409 NPs was observed using fluorescence-labeled MR409. Targeting ability and therapeutic efficacy were evaluated using a mouse MI model. Results: PEG-PPS-PEG@MR409 NPs were efficiently internalized by cardiomyocytes, reducing ROS levels and apoptosis. These NPs exhibited superior targeting to the infarcted heart compared to naked MR409 peptide. With a reduced injection frequency (once every three days), PEG-PPS-PEG@MR409 NPs significantly promoted cardiac function recovery post-MI, matching the efficacy of daily MR409 injections. Conclusion: ROS-responsive PEG-PPS-PEG polymers provide a novel and effective platform for the targeted delivery of GHRH agonist peptides, improving cardiac function and offering a new approach for peptide therapy in MI treatment.

Asunto(s)

Infarto del Miocardio , Miocitos Cardíacos , Polietilenglicoles , Especies Reactivas de Oxígeno , Animales , Polietilenglicoles/química , Polietilenglicoles/farmacocinética , Polietilenglicoles/farmacología , Especies Reactivas de Oxígeno/metabolismo , Ratones , Infarto del Miocardio/tratamiento farmacológico , Miocitos Cardíacos/efectos de los fármacos , Modelos Animales de Enfermedad , Hormona Liberadora de Hormona del Crecimiento/agonistas , Hormona Liberadora de Hormona del Crecimiento/farmacocinética , Hormona Liberadora de Hormona del Crecimiento/administración & dosificación , Apoptosis/efectos de los fármacos , Sulfuros/química , Sulfuros/farmacocinética , Sulfuros/farmacología , Sulfuros/administración & dosificación , Péptidos/química , Péptidos/farmacología , Péptidos/farmacocinética , Péptidos/administración & dosificación , Masculino , Ratones Endogámicos C57BL

RESUMEN

Currently, no safe vaccine against leishmaniasis is available. So far, different control strategies against numerous reservoir hosts and biological vectors have not been environment-friendly and feasible. Hence, employing medicinal components and conventional drugs could be a promising approach to developing novel therapeutic alternatives. This study aimed to explore diallyl sulfide (DAS), a dynamic constituent of garlic, alone and in a mixture with meglumine antimoniate (MAT as standard drug) using in vitro and animal model experiments against Leishmania major stages. The binding affinity of DAS and four major defense elements of the immune system (iNOS, IFN-É£, IL-12, and TNF-α) was used to predict the predominant binding mode for molecular docking configurations. Herein, we conducted a broad range of experiments to monitor and assess DAS and MAT potential treatment outcomes. DAS, combined with MAT, displayed no cytotoxicity and employed a powerful anti-leishmanial activity, notably against the clinical stage. The function mechanism involved immunomodulation through the induction of Th1 cytokine phenotypes, triggering a high apoptotic profile, reactive oxygen species (ROS) production, and antioxidant enzymes. This combination significantly decreased cutaneous lesion diameter and parasite load in BALB/c mice. The histopathological findings performed the infiltration of inflammatory cells associated with T-lymphocytes, particularly CD4+ phenotypes, as determined by biochemical markers in alleviating the amastigote stage and improving the pathological changes in L. major infected BALB/c mice. Therefore, DAS and MAT deserve further advanced therapeutic development and should be considered as possible candidates for treating volunteer cases with cutaneous leishmaniasis in designing an upcoming clinical trial.

Asunto(s)

Compuestos Alílicos , Antiprotozoarios , Leishmania major , Leishmaniasis Cutánea , Antimoniato de Meglumina , Ratones Endogámicos BALB C , Simulación del Acoplamiento Molecular , Sulfuros , Animales , Leishmania major/efectos de los fármacos , Antimoniato de Meglumina/farmacología , Sulfuros/farmacología , Sulfuros/química , Antiprotozoarios/farmacología , Antiprotozoarios/química , Antiprotozoarios/uso terapéutico , Leishmaniasis Cutánea/tratamiento farmacológico , Leishmaniasis Cutánea/inmunología , Leishmaniasis Cutánea/parasitología , Ratones , Compuestos Alílicos/farmacología , Compuestos Alílicos/química , Compuestos Alílicos/uso terapéutico , Compuestos Organometálicos/farmacología , Compuestos Organometálicos/química , Compuestos Organometálicos/uso terapéutico , Modelos Animales de Enfermedad , Femenino , Especies Reactivas de Oxígeno/metabolismo , Meglumina/farmacología , Meglumina/química , Citocinas/metabolismo

RESUMEN

Blood-contact devices are prone to inflammation, endothelial dysfunction, coagulation, and the uncontrolled release of metal ions during implantation and service. Therefore, it is essential to make these multifunctional. Herein, a superhydrophobic DE@ZnS-ZnO@SA film (composed of dabigatran ester, zinc sulfite, zinc oxide, and stearic acid, respectively) is produced. The prepared film has non-adhesion and antibacterial properties, superior mechanical stability, durability, corrosion resistance, and is self-cleaning and blood-repellent. The results of the hemolysis, cytotoxicity, and other anticoagulant experiments revealed that the film had good blood compatibility, no cytotoxicity, and excellent anticoagulant properties. The film displays anticoagulant properties even after being immersed in Phosphate-Buffered Saline (PBS) for 7 days. Furthermore, the film can spontaneously release H2S gas for 90 h after soaking in an acidic environment (pH = 6) for 90 h. This property improves the acidic microenvironment of the lesion and promotes the proliferation of endothelial cells by using H2S gas. In addition, the film can inhibit the uncontrollable release of Zn2+ ions, avoiding its toxicity even when immersed in an acid environment for 35 days. This time-sequential functionalized surface has the potential to typify the future of blood-contacting scaffolds for long-lasting use.

Asunto(s)

Compuestos de Zinc , Óxido de Zinc , Óxido de Zinc/química , Compuestos de Zinc/química , Humanos , Propiedades de Superficie , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Sulfuros/química , Hemólisis/efectos de los fármacos , Antibacterianos/química , Antibacterianos/farmacología , Animales , Células Endoteliales de la Vena Umbilical Humana

RESUMEN

The sulfur powder as electron donor in driving dual-chamber microbial fuel cell denitrification (S) process has the advantages in economy and pollution-free to treat nitrate-contained groundwater. However, the low efficiency of electron utilization in sulfur oxidation (ACE) is the bottleneck to this method. In this study, the addition of calcined pyrite to the S system (SCP) accelerated electron generation and intra/extracellular transfer efficiency, thereby improving ACE and denitrification performance. The highest nitrate removal rate reached to 3.55 ± 0.01 mg N/L/h in SCP system, and the ACE was 103 % higher than that in S system. More importantly, calcined pyrite enhanced the enrichment of functional bacteria (Burkholderiales, Thiomonas and Sulfurovum) and functional genes which related to sulfur metabolism and electron transfer. This study was more effective in removing nitrate from groundwater without compromising the water quality.

Asunto(s)

Fuentes de Energía Bioeléctrica , Desnitrificación , Hierro , Nitratos , Sulfuros , Azufre , Azufre/metabolismo , Nitratos/metabolismo , Sulfuros/metabolismo , Sulfuros/química , Transporte de Electrón , Hierro/metabolismo , Hierro/química , Agua Subterránea/química , Electrones , Bacterias/metabolismo , Oxidación-Reducción

RESUMEN

Garlic is a vegetable with numerous pro-health properties, showing high antioxidant capacity, and cytotoxicity for various malignant cells. The inhibition of cell proliferation by garlic is mainly attributed to the organosulfur compounds (OSCs), but it is far from obvious which constituents of garlic indeed participate in the antioxidant and cytotoxic action of garlic extracts. This study aimed to obtain insight into this question by examining the antioxidant activity and cytotoxicity of six OSCs and five phenolics present in garlic. Three common assays of antioxidant activity were employed (ABTS● decolorization, DPPH● decolorization, and FRAP). Cytotoxicity of both classes of compounds to PEO1 and SKOV-3 ovarian cancer cells, and MRC-5 fibroblasts was compared. Negligible antioxidant activities of the studied OSCs (alliin, allicin, S-allyl-D-cysteine, allyl sulfide, diallyl disulfide, and diallyl trisulfide) were observed, excluding the possibility of any significant contribution of these compounds to the total antioxidant capacity (TAC) of garlic extracts estimated by the commonly used reductive assays. Comparable cytotoxic activities of OSCs and phenolics (caffeic, p-coumaric, ferulic, gallic acids, and quercetin) indicate that both classes of compounds may contribute to the cytotoxic action of garlic.

Asunto(s)

Compuestos Alílicos , Antioxidantes , Disulfuros , Ajo , Fenoles , Extractos Vegetales , Sulfuros , Ácidos Sulfínicos , Ajo/química , Humanos , Antioxidantes/farmacología , Antioxidantes/química , Fenoles/farmacología , Fenoles/química , Disulfuros/farmacología , Disulfuros/química , Línea Celular Tumoral , Extractos Vegetales/farmacología , Extractos Vegetales/química , Ácidos Sulfínicos/farmacología , Ácidos Sulfínicos/química , Sulfuros/farmacología , Sulfuros/química , Compuestos Alílicos/farmacología , Compuestos Alílicos/química , Compuestos de Azufre/farmacología , Compuestos de Azufre/química , Cisteína/análogos & derivados , Cisteína/química , Cisteína/farmacología , Supervivencia Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo

RESUMEN

Abnormal expression in long noncoding RNAs (lncRNAs) is closely associated with cancers. Herein, a novel CRISPR/Cas13a-enhanced photocurrent-polarity-switching photoelectrochemical (PEC) biosensor was engineered for the joint detection of dual lncRNAs, using deep learning (DL) to assist in cancer diagnosis. After target lncRNA-activated CRISPR/Cas13a cleaves to induce DNAzyme bidirectional walkers with the help of cofactor Mg2+, nitrogen-doped carbon-Cu/Cu2O octahedra are introduced into the biosensor, producing a photocurrent in the opposite direction of CdS quantum dots (QDs). The developed PEC biosensor shows high specificity and sensitivity with limits of detection down to 25.5 aM for lncRNA HOTAIR and 53.1 aM for lncRNA MALAT1. More importantly, this platform for the lncRNA joint assay in whole blood can successfully differentiate cancers from healthy people. Furthermore, the DL model is applied to explore the potential pattern hidden in data of the established technology, and the accuracy of DL cancer diagnosis can acquire 93.3%. Consequently, the developed platform offers a new avenue for lncRNA joint detection and early intelligent diagnosis of cancer.

Asunto(s)

Técnicas Biosensibles , Aprendizaje Profundo , ARN Largo no Codificante , ARN Largo no Codificante/genética , Humanos , Puntos Cuánticos/química , Técnicas Electroquímicas , Sistemas CRISPR-Cas/genética , Neoplasias/diagnóstico , Neoplasias/genética , Compuestos de Cadmio/química , Sulfuros/química , Límite de Detección , Procesos Fotoquímicos

RESUMEN

Sulphidation of nZVI (S-nZVI) has shown to significantly improve the arsenic removal capacity of nZVI, concurrently modifying the sequestration mechanism. However, to better apply S-nZVI for groundwater arsenic remediation, the impact of groundwater coexisting ions on the efficacy of arsenic uptake by S-nZVI needs to be investigated. This present study evaluates the potential of S-nZVI to remove arsenic in the presence of typical groundwater coexisting ions such as Cl-, HA, HCO3-, PO43- and SO42- through batch adsorption experiments. Individually, PO43- and HA had a dominant inhibition effect, while SO42- promoted As(III) removal by S-nZVI. Conversely, for As(V) removal, HCO3- and SO42- impeded the removal process. X-ray spectroscopic investigation suggests that the coexisting ions can either compete with arsenic for the adsorption sites, influence the S-nZVI corrosion rates and/or generate distinct corrosion products, thereby interfering with arsenic removal by S-nZVI. To investigate the cumulative effects of these ions, a 25-1 Fractional Factorial Design of experiments was employed, wherein the concentration of all the ions were varied simultaneously in an optimized manner, and their impact on arsenic removal by S-nZVI was observed. Our results shows that when these ions are present concurrently, PO43-, SO42- and HA still exerted a dominant influence on As(III) removal, whereas HCO3- was the main ions affecting As(V) removal, although the combined influence of the ions was not merely a summation of their individual effects. Overall, the finding of our study might provide valuable insight for predicting the actual performance of S-nZVI in field-scale applications for the remediation of arsenic-contaminated groundwater.

Asunto(s)

Arsénico , Agua Subterránea , Hierro , Contaminantes Químicos del Agua , Agua Subterránea/química , Arsénico/química , Contaminantes Químicos del Agua/química , Hierro/química , Adsorción , Sulfuros/química , Iones , Purificación del Agua/métodos

RESUMEN

BRCA1 gene and carcinoembryonic antigen (CEA) are important markers of breast cancer, so accurate detection of them is significant for early detection and diagnosis of breast cancer. In this study, a potential-resolved ratio electrochemiluminescence (ECL) biosensor using perylene diimide (PDI)-metal-organic framework and DNA nanoflowers (NFs)-CdS quantum dots (QDs) was constructed for detection of BRCA1 and CEA. Specifically, PDI-MOF and CdS QDs can generate potential-resolved intense ECL signals only using one coreactant, so the detection procedure can be effectively simplified. PDI-MOF was first attached to the electrode by graphene oxide, and the dopamine (DA) probe was linked to quench the ECL signal by DNA hybridization. In the presence of target BRCA1, it can form a bipedal DNA walker, so the quenching molecules (DA) were detached from the electrode via the walker amplification process aided by Mg2+, so that the PDI signal at -0.25 V was restored for the BRCA1 assay. Moreover, CdS QDs@DNA NFs as amplified signal probes were formed by self-assembly, and the target CEA-amplified product introduced the CdS QDs@DNA NFs to the electrode, so the QD ECL signal at -1.42 V was enhanced, while the ECL signal of PDI is unchanged; thus, CEA detection was achieved by the ratio value between them. Therefore, the detection accuracy is guaranteed by detection of two cancer markers and a ratio value. This biosensor has a great contribution to the development of new ECL materials and a novel ECL technique for fast and efficient multitarget assays, showing great significance for the early monitoring and diagnosis of breast cancer.

Asunto(s)

Proteína BRCA1 , Técnicas Biosensibles , Compuestos de Cadmio , Antígeno Carcinoembrionario , ADN , Técnicas Electroquímicas , Imidas , Mediciones Luminiscentes , Perileno , Puntos Cuánticos , Sulfuros , Perileno/química , Perileno/análogos & derivados , Puntos Cuánticos/química , Compuestos de Cadmio/química , Técnicas Biosensibles/métodos , Sulfuros/química , Técnicas Electroquímicas/métodos , Imidas/química , ADN/química , Humanos , Proteína BRCA1/genética , Proteína BRCA1/análisis , Antígeno Carcinoembrionario/análisis , Antígeno Carcinoembrionario/sangre , Estructuras Metalorgánicas/química

RESUMEN

This study proposes an innovative strategy for achieving PN in synthetic domestic wastewater by side-stream sludge treatment using sulfide as the sole control factor. By conducting controllable batch experiments and response surface analysis, optimal sulfide treatment conditions were firstly determined as 90 mg/L of sulfide, 7.5 of pH, 100 rpm of rotation and 12 h of treatment time. After treatment, half of ammonia oxidizing bacteria (AOB) activity remained, but nitrite oxidizing bacteria (NOB) activity was barely detected. Nitrite accumulation rate of long-term running PN steadily reached 83.9 % with 99.1 % of ammonia removal efficiency. Sulfide treatment increased community diversity and facilitated stability of microbiota functioning with PN phenotype, which might be sustained by the positive correlation between ammonia oxidation gene (amoA) and sulfur oxidation gene (soxB). Correspondingly, the network analysis identified the keystone microbial taxa of persistent PN microbiota as Nitrosomonas, Thauera, Truepera, Defluviimonas and Sulitalea in the later stage of long-term reactor.

Asunto(s)

Amoníaco , Bacterias , Nitrificación , Aguas del Alcantarillado , Sulfuros , Sulfuros/química , Aguas del Alcantarillado/microbiología , Bacterias/metabolismo , Bacterias/genética , Amoníaco/metabolismo , Reactores Biológicos/microbiología , Nitritos/metabolismo , Purificación del Agua/métodos , Microbiota

RESUMEN

A peptide-catalyzed enantioselective oxidation of sulfides to yield pharmaceutically relevant chiral sulfoxides is reported. Experimental evidence suggesting that a hydrogen bond-donating moiety must be present in the substrate to achieve high levels of enantioinduction is supported by computational modeling of transition states. These models also indicate that dual points of contact between the peptidic catalyst and substrate are likely responsible for the formation of one desired sulfoxide in 94:6 er.

Asunto(s)

Ácido Aspártico , Oxidación-Reducción , Péptidos , Sulfuros , Sulfóxidos , Catálisis , Estereoisomerismo , Péptidos/química , Péptidos/síntesis química , Sulfuros/química , Ácido Aspártico/química , Sulfóxidos/química , Estructura Molecular , Enlace de Hidrógeno

RESUMEN

The resource utilization of natural pyrite not only reduces secondary pollution but also brings certain environmental benefits. However, the green and efficient use of pyrite presents certain challenges. In this study, a novel electro-Fenton (EF) system was constructed utilizing copper modified graphite felt (GF/Cu) as cathode and natural pyrite (com-FeS2) as catalyst. The results demonstrated that the system exhibited a remarkable stability over an extensive pH range (3.0-10.0) and remained effective even under adverse environmental conditions, such as high salinity or elevated antibiotic concentration. After optimizing the reaction conditions, 0.2 mM sulfamerazine (SMZ) was almost completely degraded within 1.5 h. The results highlighted the catalytic role of Fe(II) on the com-FeS2 surface. Combined with quenching experiments and quantitative analysis of reactive oxygen species (ROS), the removal of SMZ was primarily attributed to the generation of •OH, ordered by 1O2 > â€¢O2- > â€¢OHads, a possible degradation pathway was proposed by HR-LC-MS. The biological toxicity after the reaction was detected, and the introduction of polyvinylpyrrolidone (PVP) was beneficial to reduce the biological toxicity of iron dissolution. This work provides new insights into the green and efficient resource utilization of natural pyrite and significantly expands the pH applicability range of the Fenton process, demonstrating the large-scale industrial application potential of pyrite.

Asunto(s)

Hierro , Sulfuros , Hierro/química , Concentración de Iones de Hidrógeno , Sulfuros/química , Sulfuros/toxicidad , Catálisis , Peróxido de Hidrógeno/química , Contaminantes Químicos del Agua/química , Especies Reactivas de Oxígeno

RESUMEN

Iron metabolism has emerged as a promising target for cancer therapy; however, the innate metabolic compensatory capacity of cancer cells significantly limits the effectiveness of iron metabolism therapy. Herein, bioactive gallium sulfide nanodots (GaSx), with dual functions of "reprogramming" and "interfering" iron metabolic pathways, were successfully developed for tumor iron metabolism therapy. The constructed GaSx nanodots ingeniously harness hydrogen sulfide (H2S) gas, which is released in response to the tumor microenvironment, to reprogram the inherent transferrin receptor 1 (TfR1)-ferroportin 1 (FPN1) iron metabolism axis in cancer cells. Concurrently, the gallium ions (Ga3+) derived from GaSx act as a biochemical "Trojan horse", mimicking the role of iron and displacing it from essential biomolecular binding sites, thereby influencing the fate of cancer cells. By leveraging the dual mechanisms of Ga3+-mediated iron disruption and H2S-facilitated reprogramming of iron metabolic pathways, GaSx prompted the initiation of a paraptosis-apoptosis hybrid pathway in cancer cells, leading to marked suppression of tumor proliferation. Importantly, the dysregulation of iron metabolism induced by GaSx notably increased tumor cell susceptibility to both chemotherapy and immune checkpoint blockade (ICB) therapy. This study underscores the therapeutic promise of gas-based interventions and metal ion interference strategies for the tumor metabolism treatment.

Asunto(s)

Apoptosis , Galio , Hierro , Paraptosis , Animales , Humanos , Ratones , Antineoplásicos/farmacología , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Proteínas de Transporte de Catión , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Galio/química , Galio/farmacología , Sulfuro de Hidrógeno/metabolismo , Sulfuro de Hidrógeno/química , Sulfuro de Hidrógeno/farmacología , Hierro/metabolismo , Hierro/química , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Neoplasias/patología , Paraptosis/efectos de los fármacos , Receptores de Transferrina/metabolismo , Sulfuros/química , Sulfuros/farmacología , Microambiente Tumoral/efectos de los fármacos

RESUMEN

Convenient and accurate quantification of disease-relevant multitargets is essential for community disease screening. However, in the field of photoelectrochemical (PEC) sensors for multisubstance detection, research on the continuous detection of multiple targets using a polarity-switching mode is scarce. In this study, a multiplexed PEC bioassay was developed based on a target-triggered "anodic-cathodic-anodic" multiple-polarity-switchable mode. Employing miRNA-21 and miRNA-141 as model analytes, the photosensitive material combinations of Cu2O/gold nanoparticles (AuNPs)/TiO2 and CdS/AuNPs/TiO2 were successively formed through the specific binding of different whisker branches of Whisker-DNA to Cu2O-H1 and the CdS-tripod DNA ring, respectively. This process reverses the photocurrent polarity from anodic to cathodic and then back to anodic upon detecting different targets, resulting in the high-sensitivity quantification of various biological targets with reduced interference. To enhance the device's utility and affordability in community disease screening, integrating a capacitor and a multimeter-smartphone connection simplifies the assembly and reduces costs. In developing the PEC sensor, the device demonstrated linear detection ranges for miRNA-21 and miRNA-141 from 0.01 fM to 10 nM. Detection limits for miRNA-21 and miRNA-141 were established at 3.2 and 4.3 aM, respectively. The innovative target-triggered multiple-polarity-switchable mode offers adaptability for other multitarget detections by simply modifying the structure of the whisker branches and the combination of photosensitive materials.

Asunto(s)

Cobre , Técnicas Electroquímicas , Oro , Nanopartículas del Metal , MicroARNs , Titanio , MicroARNs/análisis , Oro/química , Nanopartículas del Metal/química , Titanio/química , Cobre/química , Humanos , Compuestos de Cadmio/química , Sulfuros/química , Procesos Fotoquímicos , Límite de Detección , ADN/química , ADN/análisis , Técnicas Biosensibles

RESUMEN

In this paper, Bi2S3/AgBiS2 composite nanomaterials and PDA@Ag@N-CQDs were synthesized, and used as substrates and second antibody label respectively to construct a sandwich photoelectrochemical (PEC) sensor. The upconversion luminescence effect of N-CQDs can convert long wavelength light into short wavelength light that can be utilized by the substrate material, which can provide additional excitation light energy for the substrate material and further enhance the photoelectric response. Besides, Ag has SPR effect and can also promote electron transfer. The proposed sandwich immunosensor achieves detection of NSE in the concentration range of 0.001 ng mL-1 to 100 ng mL-1, with a detection limit of 0.28 pg mL-1 (S/N = 3). What's more, the proposed sensor also exhibits good stability, selectivity, as well as reproducibility, indicating its promising application prospects.

Asunto(s)

Bismuto , Técnicas Electroquímicas , Fosfopiruvato Hidratasa , Plata , Plata/química , Fosfopiruvato Hidratasa/análisis , Bismuto/química , Humanos , Técnicas Biosensibles/métodos , Límite de Detección , Procesos Fotoquímicos , Luminiscencia , Sulfuros/química