Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.093
Filtrar
1.
ACS Omega ; 9(37): 38678-38685, 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39310187

RESUMEN

The use of fluorescent nanoparticles (NPs) for tracing purposes in oilfields encounters challenges due to background interferences under constant external excitation caused by organic residues present in crude oil. This results in insufficient sensitivity and lower tracer detection limits in the crude oil/water emulsions. In this study, we present the synthesis of persistent luminescent NPs, showcasing their remarkable application as tracers in crude oil. The multiband MgAl0.05Ge0.95O3:0.3%Pr3+ persistent NPs were synthesized via the sol-gel method. Through meticulous experimentation and analysis, our study unveils a novel avenue for efficient and lasting traceability in crude oil. The synthesized NPs emit light across the visible, near-infrared, and shortwave infrared regions, allowing for versatile detection. The unique luminescent properties of these NPs, particularly their ability to persist in emitting light without a continuous external excitation, enable their effective use as tracers in crude oil/water emulsions where background fluorescence typically poses a significant challenge. By employing these persistent NPs in background fluorescence-free conditions, we achieve ultrahigh sensitivity in detecting these NPs in crude oil. Our research reveals that the doping of Al3+ ions significantly enhances both the afterglow intensity of MgGeO3:0.3%Pr3+ phosphor and the afterglow decay time of Pr3+ emission. This characteristic enables the re-excitation of MgAl0.05G0.95O:0.3%Pr3+ NPs within the emulsion, allowing for repeated spectral and imaging acquisition. This high sensitivity not only facilitates precise imaging of NPs in crude oil but also enables long-term monitoring in real-time, offering valuable insights for oilfield operations.

2.
Medicina (Kaunas) ; 60(9)2024 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-39336582

RESUMEN

Background and Objectives: Diabetes is a global health issue, with approximately 50% of patients developing diabetic nephropathy (DN) and 25% experiencing early and severe forms of the disease. The genetic factors contributing to rapid disease progression in a subset of these patients are unclear. This study investigates genetic variations in the GLO-1, CBR-1, and ACE genes associated with early and severe DN. Materials and Methods: Sanger DNA sequencing of the exons of CBR1, GLO1, and ACE genes was conducted in 113 patients with early and severe DN (defined as occurring within 10 years of the diagnosis of diabetes and with eGFR < 45 mL/min/1.73 m2) and 100 controls. The impact of identified genetic variations was analyzed using computational protein models created in silico with SWISS-Model and SWISS-Dock for ligand binding interactions. Results: In GLO1, two heterozygous missense mutations, c.102G>T and c.147C>G, and one heterozygous nonsense mutation, c.148G>T, were identified in patients. The SNP rs1049346 (G>A) at location 6:38703061 (GRCh38) was clinically significant. The c.147C>G mutation (C19S) was associated with ligand binding disruption in the GLO1 protein, while the nonsense mutation resulted in a truncated, non-functional protein. In CBR1, two heterozygous variations, one missense c.358G>A, and one silent mutation c.311G>C were observed, with the former (D120N) affecting the active site. No significant changes were noted in ACE gene variants concerning protein structure or function. Conclusions: The study identifies four novel and five recurrent mutations/polymorphisms in GLO1, ACE, and CBR1 genes associated with severe DN in Pakistani patients. Notably, a nonsense mutation in GLO1 led to a truncated, non-functional protein, while missense mutations in GLO1 and CBR1 potentially disrupt enzyme function, possibly accelerating DN progression.


Asunto(s)
Nefropatías Diabéticas , Lactoilglutatión Liasa , Peptidil-Dipeptidasa A , Humanos , Nefropatías Diabéticas/genética , Femenino , Masculino , Persona de Mediana Edad , Lactoilglutatión Liasa/genética , Peptidil-Dipeptidasa A/genética , Anciano , Adulto , Análisis de Secuencia de ADN/métodos , Polimorfismo de Nucleótido Simple , Mutación Missense , Aldehído Reductasa
3.
J Chem Phys ; 161(10)2024 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-39254161

RESUMEN

We conduct systematic studies of the optical characteristics of plasmonic nanoparticles that exhibit C2v symmetry. In particular, we analyze three distinct geometric configurations: an L-type shape, a crescent, and a split-ring resonator shaped like the Greek letter π. Optical properties are examined using the finite-difference time-domain method. It is demonstrated that all three shapes exhibit two prominent plasmon modes associated with the two axes of symmetry. This is in addition to a wide range of resonances observed at high frequencies corresponding to quadrupole modes and peaks due to sharp corners. Next, to facilitate nonlinear analysis, we employ a semiclassical hydrodynamic model, where the electron pressure term is explicitly accounted for. This model goes beyond the standard Drude description and enables capturing nonlocal and nonlinear effects. Employing this model enables us to rigorously examine the second-order angular resolved nonlinear optical response of these nanoparticles in each of the three configurations. Two pumping regimes are considered, namely, continuous wave (CW) and pulsed excitations. For CW pumping, we explore the properties of the second harmonic generation (SHG). Polarization and angle-resolved SHG spectra are obtained, revealing strong dependence on the nanoparticle geometry and incident wave polarization. The C2v symmetry is shown to play a key role in determining the polarization states and selection rules of the SHG signal. For pulsed excitations, we discuss the phenomenon of broadband terahertz (THz) generation induced by the difference-frequency generation . It is shown that the THz emission spectra exhibit unique features attributed to the plasmonic resonances and symmetry of the nanoparticles. The polarization of the generated THz waves is also examined, revealing interesting patterns tied to the nanoparticle geometry. To gain deeper insight, we propose an analytical theory that agrees very well with the numerical experiments. The theory shows that the physical origin of the THz radiation is the mixing of various frequency components of the fundamental pulse by the second-order nonlinear susceptibility. An expression for the far-field THz intensity is derived in terms of the incident pulse parameters and the nonlinear response tensor of the nanoparticle. The results presented in this work offer new insights into the linear and nonlinear optical properties of nanoparticles with C2v symmetry. The demonstrated strong SHG response and efficient broadband THz generation hold great promise for applications in nonlinear spectroscopy, nanophotonics, and optoelectronics. The proposed theoretical framework also provides a valuable tool for understanding and predicting the nonlinear behavior of other related nanostructures.

4.
PLoS One ; 19(9): e0300979, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39283918

RESUMEN

As the effectiveness of current treatments against the development of antimicrobial resistance is declining, new strategies are required. A great source of novel secondary metabolites with therapeutics effects are the endophytic bacteria present in medicinal plants. In this study, Klebsiella aerogenes (an endophytic bacteria belonging to the Enterobacteriaceae family) was isolated from Kalanchoe blossfeldiana (a medicinal plant". The bacterial secondary metabolites were identified using GC-MS techniques. Furthermore, the antibacterial potentials were investigated against multi-drug resistance (MDR) Salmonella typhi and Staphylococcus aureus. The GC-MS chromatogram of K. aerogenes secondary metabolites extract displayed total of 36 compounds. Ethyl acetate extracts of K. aerogenes, showed mean zone of growth inhibition of 15.00 ± 1.00 against S. typhi and 7.00 ± 1.00mm against S. aureus, respectively. The extract demonstrated significant antibacterial effectiveness against S. typhi and moderate antibacterial efficacy against S. aureus, with minimum inhibitory concentration (MIC) values ranging from 0.089 to 0.39 mg/mL. The time-kill kinetics profile of the ethyl acetate extract against S. typhi revealed a decrease in the number of viable cells during the initial 5, 6, and 24 hours. Conversely, there was a sudden increase in viable cells up to 6 hours for S. aureus. The identified secondary metabolite with high percentage than others, benzeneethanamine exhibited favorable interactions (-7.2 kcal/mol) with the penicillin-binding protein (PBP2a) of S. aureus and (-7.5 kcal/mol) osmoporin (OmpC) of S. typhi, indicating its potential as a candidate for drug development against these MDR bacteria. This study reported for the first time, bacterial endophytes associated with K. blossfeldiana with antibacterial activities.


Asunto(s)
Antibacterianos , Farmacorresistencia Bacteriana Múltiple , Enterobacter aerogenes , Pruebas de Sensibilidad Microbiana , Staphylococcus aureus , Antibacterianos/farmacología , Antibacterianos/química , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Enterobacter aerogenes/efectos de los fármacos , Enterobacter aerogenes/metabolismo , Staphylococcus aureus/efectos de los fármacos , Salmonella typhi/efectos de los fármacos , Metabolismo Secundario , Extractos Vegetales/farmacología , Extractos Vegetales/química
5.
Protein J ; 43(5): 1009-1024, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39222239

RESUMEN

A diminutive chemical library of acyl thiotriazinoindole (ATTI) based bioactive scaffolds was synthesized, instigated by taking the economical starting material Isatin, through a series of five steps. Isatin was first nitrated followed by the attachment of pentyl moiety via nucleophilic substitution reaction. The obtained compound was reacted with thiosemicarbazide to obtain thiosemicarbazone derivative, which was eventually cyclized using basic conditions in water as solvent. Finally, the reported series was obtained through reaction of nitrated thiotriazinoindole moiety with differently substituted phenacyl bromides. The synthesized compounds were characterized using NMR spectroscopy and elemental analysis. Finally, the synthesized motifs were scrutinized for their potential to impede urease, α-glucosidase, DPPH, and α-amylase. Compound 5 h with para cyano group manifested the most pivotal biological activity among all, displaying IC50 values of 29.7 ± 0.8, 20.5 ± 0.5 and 36.8 ± 3.9 µM against urease, α-glucosidase, and DPPH assay, respectively. Simultaneously, for α-amylase compound 5 g possessing a p-CH3 at phenyl ring unfolded as most active, with calculated IC50 values 90.3 ± 1.1 µM. The scaffolds were additionally gauged for their antifungal and antibacterial activity. Among the tested strains, 5d having bromo as substituent exhibited the most potent antibacterial activity, while it also demonstrated the highest potency against Aspergillus fumigatus. Other derivatives 5b, 5e, 5i, and 5j also exhibited dual inhibition against both antibacterial and antifungal strains. The interaction pattern of derivatives clearly displayed their SAR, and their docking scores were correlated with their IC50 values. In molecular docking studies, the importance of interactions like hydrogen bonding was further asserted. The electronic factors of various substituents engendered variety of interactions between the ligands and targets implying their importance in the structures of the synthesized heterocyclic scaffolds. To conclude, the synthesized compounds had satisfactory biological activity against various important targets. Further studies are therefore encouraged by attachment of different substitutions in the structure at various positions to enhance the activity of these compounds.


Asunto(s)
Antioxidantes , Simulación del Acoplamiento Molecular , Ureasa , alfa-Amilasas , alfa-Glucosidasas , Ureasa/antagonistas & inhibidores , Ureasa/química , alfa-Amilasas/antagonistas & inhibidores , alfa-Amilasas/química , alfa-Glucosidasas/química , alfa-Glucosidasas/metabolismo , Antioxidantes/química , Antioxidantes/farmacología , Antioxidantes/síntesis química , Relación Estructura-Actividad , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Diseño de Fármacos , Indoles/química , Indoles/farmacología , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/síntesis química , Inhibidores de Glicósido Hidrolasas/química , Inhibidores de Glicósido Hidrolasas/farmacología , Inhibidores de Glicósido Hidrolasas/síntesis química , Pruebas de Sensibilidad Microbiana
6.
Discov Med ; 36(188): 1848-1857, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39327248

RESUMEN

BACKGROUND: Helicobacter pylori (H. pylori)is a Gram-negative, microaerophilic, and spiral shape bacterium that resides inside the human stomach. The human stomach serves as its primary reservoir. Complaints about stomach complication due to H. pylori infections are reported in the majority of populations around the globe. Chronic gastritis and intestinal metaplasia of the gastric mucosa are major complications of a long-term H. pylori infections that can lead to gastric cancer in severe cases. This study aims to characterize H. pylori isolates from gastroenteritis patients and to determine the resistance of H. pylori to various antibiotics. METHODS: In the current study, a total of (n = 80) gastric biopsy samples were randomly collected from gastroenteritis patients in brain-heart infusion broth. These were inoculated on Columbia blood agar supplemented with Helicobacter pylori selective supplement (DENT). After culturing, Microscopy and biochemical tests were performed. The susceptibility profile of H. pylori isolates was evaluated using the Kirby Bauer disk diffusion method. On the basis of the drug resistance profile, a total of (n = 20) isolates including (n = 10) from females and (n = 10) from males were selected for the detection and characterization of resistant genes. After confirmation of H. pylori using 16s rRNA, polymerase chain reaction (PCR) was done for the detection of resistance genes including Metronidazole resistance (rdxA gene), Clarithromycin resistance (23s rRNA gene) and Amoxicillin resistance (Penicillin-binding protein A1 (pbpA1) gene). RESULTS: In a total of (n = 80) samples, H. pylori was isolated from 72.5% (n = 58) samples. Among the positive patients, there were 62% (n = 36) of female positive patients while in males, its ratio was 38% (n = 22). It was more common in the age between 30-50 years 55.17% (n = 32). It has shown the highest resistance towards Metronidazole 90% (n = 52), and the lowest toward Levofloxacin 65% (n = 38). Metronidazole resistance gene (rdxA gene) was detected in (n = 13) isolates including (n = 9) isolates from females and (n = 4) from males. In the case of, the Clarithromycin resistance gene (23s rRNA) (n = 10) was positive for H. pylori including (n = 6) isolates from females and (n = 7) were positive for Amoxicillin (pbpA1 gene) including (n = 2) in female and (n = 5) from male patients. CONCLUSION: This study highlights the increasing incidence of H. pylori infections in both male and female patients. It also revealed the current status of antibiotic resistance and its resistance genes in patients facing gastrointestinal issues. Continuous surveillance of resistant clones will help in formulating strategies that can help in combating of resistant clone. It will also help clinician in proper prescription and management of H. pylori infections.


Asunto(s)
Amoxicilina , Antibacterianos , Claritromicina , Farmacorresistencia Bacteriana , Gastroenteritis , Infecciones por Helicobacter , Helicobacter pylori , Metronidazol , Humanos , Helicobacter pylori/genética , Helicobacter pylori/efectos de los fármacos , Helicobacter pylori/aislamiento & purificación , Claritromicina/farmacología , Femenino , Amoxicilina/farmacología , Masculino , Metronidazol/farmacología , Infecciones por Helicobacter/microbiología , Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/complicaciones , Gastroenteritis/microbiología , Gastroenteritis/tratamiento farmacológico , Farmacorresistencia Bacteriana/genética , Adulto , Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Proteínas Bacterianas/genética
7.
Artículo en Inglés | MEDLINE | ID: mdl-39323117

RESUMEN

This study focused on analyzing the pharmacological activities of AgNPs synthesized from an aqueous plant extract of Anchusa arvensis. The effectiveness of AgNPs was evaluated for protein kinase inhibition, antioxidant, antibacterial, and antifungal activities. The AgNPs and plant were used to regulate the protein kinase activity using the liquid TSB and ISP4 medium protein kinase inhibition study demonstrated that nanoparticles exhibited a larger zone of inhibition (9.1 ± 0.8) compared to the plant extract (8.1 ± 0.6). The antioxidant activity was assessed using DPPH reagent, and the results indicated that AgNPs displayed potent free radical scavenging properties. In terms of antibacterial activity, AgNPs showed higher efficacy against Enterobacter aerogens (20.1 ± 0.9), Bordetella bronchiseptaca (19.1 ± 0.9), and Salmonella typhimurium (17.2 ± 0.8) at 4 mg/mL. The antifungal activity of AgNPs was prominent against Aspergillus fumagatus (14.1 ± 0.9), Mucor species (19.2 ± 0.8), and Fusarium solani (11.2 ± 0.8) at 20 mg/mL. These findings suggest that AgNPs possess multiple beneficial properties, including bactericidal/fungicidal effects, protein kinase inhibition, and potential free radical scavenging abilities. Therefore, AgNPs have potential applications in various fields, such as biomedicine and industry, due to their ability to counteract the harmful effects of free radicals.

8.
Aquat Toxicol ; 276: 107098, 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39298911

RESUMEN

Yangtze finless porpoises (YFP) accumulate high levels of per- and polyfluoroalkyl substances (PFASs). However, the health impacts of PFASs to YFP are still unknown because it is technically and ethically unfeasible to use the critically endangered YFP in toxicological exposures. To uncover the potential toxicities of PFASs to YFP, this study exposed a YFP umbilical cord fibroblast cell line to perfluorobutane sulfonate (PFBS), an emerging PFASs pollutant in the aquatic environments. After exposure, the cytotoxicity and mechanisms of PFBS were explored. Our preliminary experiments found that PFBS compromised the cell viability in a concentration and duration dependent manner. In an exposure of 48-h duration, the maximum no observed effect concentration (NOEC) of PFBS was determined to be 400 µM. High-throughput proteomics were then conducted to identify the differentially expressed proteins in YFP cells exposed to 400 µM PFBS for 48 h. The results found that PFBS exposure significantly perturbed the proteome fingerprints of YFP umbilical cord fibroblast cells. Functional annotation of differential proteins showed that PFBS had the potential to impair a variety of biological processes associated with the immunity, oxidative stress, metabolism, and proteolysis. Consistently, the intracellular levels of reactive oxygen species (ROS) and proinflammatory cytokine IL-1ß were significantly increased by PFBS in YFP umbilical cord fibroblast cells. Overall, this study highlights the toxic effects of emerging PFASs on YFP and provides reference data to evaluate the health risks of aquatic pollution under the context of national YFP protection. To our knowledge, this is the first omics study using YFP umbilical cord fibroblast cells in ecotoxicology of PFASs, which is applicable to various cetacean species and pollutants.

9.
Mol Cell ; 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39303720

RESUMEN

Cys2-His2 zinc-finger proteins (C2H2-ZNFs) constitute the largest class of DNA-binding transcription factors (TFs) yet remain largely uncharacterized. Although certain family members, e.g., GTF3A, have been shown to bind both DNA and RNA, the extent to which C2H2-ZNFs interact with-and regulate-RNA-associated processes is not known. Using UV crosslinking and immunoprecipitation (CLIP), we observe that 148 of 150 analyzed C2H2-ZNFs bind directly to RNA in human cells. By integrating CLIP sequencing (CLIP-seq) RNA-binding maps for 50 of these C2H2-ZNFs with data from chromatin immunoprecipitation sequencing (ChIP-seq), protein-protein interaction assays, and transcriptome profiling experiments, we observe that the RNA-binding profiles of C2H2-ZNFs are generally distinct from their DNA-binding preferences and that they regulate a variety of post-transcriptional processes, including pre-mRNA splicing, cleavage and polyadenylation, and m6A modification of mRNA. Our results thus define a substantially expanded repertoire of C2H2-ZNFs that bind RNA and provide an important resource for elucidating post-transcriptional regulatory programs.

10.
Genome Biol ; 25(1): 246, 2024 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-39300486

RESUMEN

BACKGROUND: N6-methyladenosine (m6A), the most abundant internal modification on eukaryotic mRNA, and N6, 2'-O-dimethyladenosine (m6Am), are epitranscriptomic marks that function in multiple aspects of posttranscriptional regulation. Fat mass and obesity-associated protein (FTO) can remove both m6A and m6Am; however, little is known about how FTO achieves its substrate selectivity. RESULTS: Here, we demonstrate that ZBTB48, a C2H2-zinc finger protein that functions in telomere maintenance, associates with FTO and binds both mRNA and the telomere-associated regulatory RNA TERRA to regulate the functional interactions of FTO with target transcripts. Specifically, depletion of ZBTB48 affects targeting of FTO to sites of m6A/m6Am modification, changes cellular m6A/m6Am levels and, consequently, alters decay rates of target RNAs. ZBTB48 ablation also accelerates growth of HCT-116 colorectal cancer cells and modulates FTO-dependent regulation of Metastasis-associated protein 1 (MTA1) transcripts by controlling the binding to MTA1 mRNA of the m6A reader IGF2BP2. CONCLUSIONS: Our findings thus uncover a previously unknown mechanism of posttranscriptional regulation in which ZBTB48 co-ordinates RNA-binding of the m6A/m6Am demethylase FTO to control expression of its target RNAs.


Asunto(s)
Adenosina , Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato , Humanos , Adenosina/análogos & derivados , Adenosina/metabolismo , Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato/metabolismo , Dioxigenasa FTO Dependiente de Alfa-Cetoglutarato/genética , Células HCT116 , ARN Mensajero/metabolismo , ARN Mensajero/genética , Telómero/metabolismo , Telómero/genética , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Dedos de Zinc
11.
Heliyon ; 10(17): e36758, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-39281648

RESUMEN

In this study, biocrude was successfully produced by the hydrothermal liquefaction of municipal solid waste collected from the landfill site of Lahore, the capital of Punjab, Pakistan, boasting a population of 12 million and an annual waste collection of 10 million tons. The hydrothermal liquefaction process was performed at reaction parameters of 350 °C and 165 bars with 15 min of residence time. The solid waste was found to have 78 % dry matter, 22 % moisture contents, 22.2 % ash, 22.69 MJ/kg higher heating value, 52.062 % C, 8.007 % H, 0.764 % N, and 39.164 % O. Non-catalytic process only produced 10.57 % oil, however when using the catalytic process, the biocrude yield improved to 17.61 %, with 22.61 % energy recovery for biocrude and 12.14 % for solids, when using 2 g dose of K2CO3. The resultant biocrude has a 28.61 MJ/kg higher heating value, having 60.28 % C and 9.28 % H. In contrast, the aqueous phase generated had 4.43 pH, 71.5 g/L TOC, and 1.35 g/L Total Nitrogen. TGA indicated that biocrude contains approximately 80 % of volatile fractions of different fuels. The organic compounds having the six highest peak areas in GC-MS were Ethyl ether 25.74 %, 2-pentanone, 4-hydroxy-4-methyl 9.08 %, 2-propanone, 1,1-dimethoxy 5.62 %, Silane, dimethyl (docosyloxy) butoxy 5.08 %, 1-Hexanol, 2-ethyl 4.53 %, and. Phenol 4.07 %. This work makes the first-ever successful use of indigenous solid waste from a landfill dumping site in Lahore to successfully produce useful biocrude with aims of waste reduction and management, circular economy, and energy recovery.

12.
Nanoscale ; 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39235291

RESUMEN

The investigation of nanocluster behaviors at elevated temperatures is important because it encompasses temperature-dependent structural evolution and size-dependent melting points. Size-selected Au2057±52, Au923±24, Au1846±48, and Au2769±72 clusters were generated using a gas-phase condensation cluster beam source equipped with a lateral time-of-flight mass selector. Comprehensive in situ heating characterization was conducted, revealing the structural evolution and size-dependent melting point depression of AuN clusters at atomic resolution via aberration-corrected scanning transmission electron microscopy (AC-STEM). Using quantitative (Q)STEM simulations, a comprehensive statistical analysis was conducted to investigate the structural characteristics of the Au clusters. These clusters tended to be kinetically trapped in metastable structures during nucleation, which subsequently served as "growth templates" for the formation of many metastable Au clusters. In situ heating experiments performed on Au2057±52 revealed a structural evolution trend from icosahedron (Ih) to decahedron (Dh) and finally to face-centered cubic (FCC) structures, with noticeable competition being observed between the Dh and FCC structures. AC-STEM imaging revealed that the melting of the Au clusters began with the formation of molten liquid shells on the surface. The liquid shells thickened at higher temperatures, and the solid core suddenly melted when its diameter decreased to a critical size. Furthermore, the melting points of the Au clusters were linearly dependent on the reciprocal diameter. Compared with the theoretical models, it was found that the liquid nucleation and growth model is in good agreement with the experimental results, indicating its suitability for describing the surface core melting processes of Au clusters at the studied scales.

13.
Future Med Chem ; : 1-11, 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39269160

RESUMEN

Aim: Current study aims exploration of bis-benzoxazole bearing bis-Schiff base scaffolds (1-16) as anti-Alzheimer's agents.Materials & methods: 2-aminophenol is used as starting materials which react with different reagents in different step to give us bis-benzoxazole bearing bis-Schiff base analogs. NMR and HREI-MS techniques were used for characterization. All derivatives demonstrated varied range of activities with IC50 values 1.10 ± 0.40-24.50 ± 0.90 µM against acetylcholinesterase (AChE) and 1.90 ± 0.70-28.60 ± 0.60 µM against butyrylcholinesterase (BuChE) in contrast to donepezil. In both cases, analog-3 was found most potent. Molecular docking explored modes of interactions between scaffolds and receptor sites of targeted enzymes.Conclusion: This study offering promising approach for optimization and development of potent inhibitors of cholinesterase enzymes.


[Box: see text].

14.
J Environ Manage ; 370: 122459, 2024 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-39270341

RESUMEN

Recently, the UN has suggested several green initiatives to adopt renewable energy consumption in human & economic activities. Therefore, most practitioners have followed the responsible production & consumption (RP&C) pattern under SDG 12 to increase economic progress. This study considers the top 15 circular economies that are ruthless in producing and consuming energy greenly. This study finds the circular economy, digital technologies, natural resource utilization, empowerment, environmental policy, and environmental degradation as decisive factors for the RP&C of energy. Similarly, the current empirical research utilizes an advanced series of estimators to investigate the study's objective. However, the long-term outcomes show a significant contribution to responsible production by circular economy while remaining insignificant for production. Under RP&C base models, this study obtains a 1.830% change in consumption and 0.135% in energy production via a significant shift in digital technologies. Furthermore, environmental policy and empowerment are positively associated with RP&C in the specified region. The role of natural resources is inversely but insignificantly related to responsible consumption and vice versa for the production side. Rising environmental concerns show a heterogeneous role for both models. This study also investigates the mediating role of digital technologies on circular economy, natural resources, and empowerment and supports the positive association in RP&C. This study suggests some implications to support SDG 12 further.

15.
Small ; : e2407594, 2024 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-39344557

RESUMEN

Tuning the adsorption energy of nitrogen intermediates and lowering the reaction energy barrier is essential to accelerate the kinetics of nitrogen reduction reaction (NRR), yet remains a great challenge. Herein, the electronic structure of WS2 is tailored based on a metal and nonmetal dual-doping strategy (denoted Fe, F-WS2) to lower the d-band center of W in order to optimize the adsorption of nitrogen intermediates. The obtained Fe, F-WS2 nanosheet catalyst presents a high Faradic efficiency (FE) of 22.42% with a NH3 yield rate of 91.46 µg h-1 mgcat. -1. The in situ characterizations and DFT simulations consistently show the enhanced activity is attributed to the downshift of the d-band center, which contributes to the rate-determining step of the second protonation to form N2H2 * key intermediates, thereby boosting the overall nitrogen electrocatalysis reaction kinetics. This work opens a new avenue to enhanced electrocatalysis by modulating the electronic structure and surrounding microenvironment of the catalytic metal centers.

16.
ACS Appl Mater Interfaces ; 16(35): 46191-46199, 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39166740

RESUMEN

The pursuit of high-performance thermoelectric materials is of paramount importance in addressing energy sustainability and environmental concerns. Here, we explore the multifaceted impact of sulfur passivation in the matrix of tellurium nanowires (TeNWs), encompassing environmental control, thermoelectric properties, and charge carrier mobility. In this study, we present the facile production of TeNWs using an aqueous solution synthesis approach. The synthesized TeNWs were subsequently subjected to surface modification involving sulfur moieties. Our findings demonstrate that sulfur passivation not only effectively safeguards the nanowires from environmental degradation but also significantly augments their thermoelectric properties. Notably, the highest recorded values were achieved at 560 K for passivated tellurium nanowires, exhibiting a Seebeck coefficient of 246 µV/K, an electrical conductivity of 14.2 S/cm, and power factors of 86.7 µW/m-K2. This strategy presents a promising avenue for the development of advanced thermoelectric materials for applications in energy harvesting, waste heat recovery, and sustainable energy conversion technologies.

17.
Chemosphere ; 364: 143194, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39209044

RESUMEN

MXenes are a group of 2D material which have been derived from the layered transition metal nitrides and carbides and have the characteristics like electrical conductivity, high surface area and variable surface chemical composition. Self-assembly of clusters/metal ions and organic linkers forms metal organic framework (MOF). Their advantages of ultrahigh porosity, highly exposed active sites and many pore architectures have garnered them a lot of attention. But poor conductivity and instability plague several conventional MOF. To address the issue, MOF can be linked with MXenes that have rich surface functional groups and excellent electrical conductivity. In this review, different etching methods for exfoliation of MXene along with the synthesis methods of MXene/MOF composites are reviewed, including hydrothermal method, solvothermal method, in-situ growth method, and self-assembly method. Moreover, application of these MXene/MOF composites for catalytic water splitting and wastewater treatment were also discussed in details. In addition to increasing a single MOF conductivity and stability, MXenes can add a variety of new features, such the template effect. Due to these benefits, MXene/MOF composites can be effectively used in several applications, including photocatalytic/electrocatalytic water splitting, adsorption and degradation of pollutants from wastewater. Finally, the authors explored the current challenges and the future opportunities to improve the efficiency of MXene/MOF composites.


Asunto(s)
Estructuras Metalorgánicas , Aguas Residuales , Purificación del Agua , Estructuras Metalorgánicas/química , Aguas Residuales/química , Catálisis , Purificación del Agua/métodos , Agua/química , Adsorción , Contaminantes Químicos del Agua/química , Eliminación de Residuos Líquidos/métodos
18.
Heliyon ; 10(14): e34266, 2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-39108848

RESUMEN

Widespread ecosystem degradation from noxious substances like industrial waste, toxic dyes, pesticides, and herbicides poses serious environmental risks. For remediation of these hazardous problems, present study introduces an innovative Cu-doped Ce2Zr2O7 nano-photocatalyst, fabricated via a simple, eco-friendly hydrothermal method, designed to degrade toxic textile dye methylene blue. Harnessing Cu doping for pyrochlore Ce2Zr2O7, structure engineering carried out through a hydrothermal synthesis method to achieve superior photocatalytic performance, addressing limitations of rapid charge carrier recombination in existing photocatalysts. Photoluminescence analysis showed that doped pyrochlore slows charge carrier recombination, boosting dye degradation efficiency. UV-Visible analysis demonstrated an impressive 96 % degradation of methylene blue by Cu-doped Ce2Zr2O7 within 50 min, far exceeding the performance of pristine materials. Trapping experiments clarified the charge transfer mechanism, deepening our understanding of the photocatalytic process. These findings highlight the potential for developing innovative, highly efficient photocatalysts for environmental remediation, offering sustainable solutions to combat pollution. This study not only addresses the limitations of existing photocatalysts but also opens new avenues for enhancing photocatalytic performance through strategic material design.

19.
Biol Reprod ; 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39135547

RESUMEN

The gestation period in captive Yangtze finless porpoise (YFP) is a well-coordinated and dynamic process that involves both systemic and local alterations. The gut microbiota and its connection to fecal metabolites are crucial in supporting fetal development and ensuring maternal health during reproductive stages. This study evaluates changes in the gut microbiota and their correlation with fecal metabolites in captive YFPs during different reproductive stages. The results reveal that microbial community structure changed significantly during reproductive stages, while gut microbial diversity remained stable. The genus unclassified Peptostrptococcaceae, Corynebacterium, and norank KD4-96 were significantly greater in non-pregnancy (NP), Terrisporobacter was significantly greater in lactating (LL), and Clostridium was significantly higher in early-pregnancy (EP) compared to the other groups. The host fecal metabolome exhibited significant alterations during the reproductive stages. Indoxyl sulfate, octadecatrienoic acid, and methionyl-methionine were significantly higher in the NP; galactosylglycerol, chondroitin 6-sulfate, and lumichrome were significantly higher in the EP and mid-pregnancy (MP); and valylleucine and butyryl-l-carnitine were significantly higher in the LL. The altered metabolites were mostly concentrated in pathways associated with arachidonic acid metabolism (significantly altered in NP), leucine, valine, and isoleucine biosynthesis (significantly altered in EP and MP), and glycerophospholipid metabolism (significantly altered in LL compared to others stages). Additionally, we found a strong link between variations in the host metabolism and alterations in the fecal bacteria of captive YFP. In conclusion, this study provides detailed insights into host metabolic and fecal bacterial changes in captive YFP during reproduction stages, providing important knowledge for improving the reproductive management in the captive YFP.

20.
Nanoscale Adv ; 6(16): 4237-4246, 2024 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-39114148

RESUMEN

The emerging technique of nano-welding (NW) via precisely regulating the fusion of nanoclusters (NCs) in nanotechnology has attracted significant attention for its innovative approach. Employing the gas-phase condensation cluster source with a lateral time-of-flight (TOF) mass-selector, size-selected gold (Au), and tantalum (Ta) NCs were prepared. This study explores the coalescence behavior of size-selected Au and Ta NCs under electron beam irradiation, aiming to investigate the related mechanism governing the welding process. Intrinsically driven by the reduction of excess surface energy, electron beam induces atomic thermal migration, fostering sintering neck growth at cluster interfaces. During this process, atomic diffusion and recrystallization enable NCs to alter shape while retaining stable facet planes. Aberration-corrected scanning transmission electron microscopy (AC-STEM) showcases the formation of single or polycrystalline sintered clusters, during which some lattice distortions can be eliminated. Interestingly, oxidized Ta clusters experience knock-on damage caused by elastic scattering of electron beams, partially deoxidizing them. Additionally, electron-phonon inelastic scattering transforms oxidized Ta clusters from amorphous to crystalline structures. Moreover, the quantum size effect and surface effect of NCs facilitate the surpassing of miscibility limits during Au-Ta heterogeneous welding processes. This investigation bridges the gap between fundamental research on cluster materials and their practical applications.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...