Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 296
Filtrar
1.
Angew Chem Int Ed Engl ; : e202414073, 2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39248641

RESUMEN

Local enrichment of free radicals at the electrode interface may open new opportunities for the development of electrochemiluminescence (ECL) applications. The sensing platform was constructed by assembling ECL-emitting luminol derived carbon dots (Lu CDs) onto the heterojunction Tungsten disulfide/Covalent organic frameworks (WS2@COF) for the first time, establishing a nanoconfinement-reactor with significantly heightened ECL intensity and stability compared to the Lu CDs-H2O2 system. This enhanced performance is credited to the COF domain's restricted pore environment, where WS2@COF exhibits a more negative adsorption energy for H2O2, effectively enriching H2O2 in the catalytic edge sites of WS2. Furthermore, the internal electric field at the WS2 and COF interface accelerates electron flow, boosting WS2's catalytic activity and achieving domain-limited catalytic enhancement of ECL. Self-designed DNA nanomachines combined with cascading molecular keypad locking mechanisms are integrated into the biosensors, effectively guaranteeing the accuracy of the sensing process while providing crucial safeguards for molecular diagnostics and information security applications. In essence, this innovative approach represents the first system to enhance local free radical concentrations by enriching co-reactants on the electrode surface through nanoconfinement catalysis, yielding heightened ECL luminescence intensity. The potential impact of this novel strategy and sensing mechanism on real-bioanalysis applications is promising.

2.
Anal Methods ; 2024 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-39264253

RESUMEN

Bimetallic nanomaterial-based systems have been widely utilized across various fields due to their remarkable expandability and flexibility, including nanomedicine, diagnostics, and molecular information technology. Here, we constructed an electrochemical immunosensor using bimetallic gold/silver functionalized carbon spheres (AuAg@CSs) and mesoporous silica nanoparticles (MSNs) for the sensitive determination of cytokeratin 19 fragment antigen 21-1 (CYFRA 21-1) and ensuring information protection for textual data. The AuAg@CSs demonstrated exceptional catalytic activity towards hydrogen peroxide, generating a significant current signal. The introduction of CYFRA 21-1 facilitated the binding of MSNs, thereby forming a sandwich-type electrochemical immunosensor that resulted in a notable decrease in current. Notably, the detection limit for CYFRA 21-1 was determined to be 31 fg mL-1, accompanied by high selectivity. Furthermore, extensive textual information can be encrypted and concealed within the current responses of the electrochemical nanosensing system. By establishing a threshold, these current signals can be represented as a series of binary strings, which can subsequently be segmented into shorter strings. Through information coding methods, these shorter binary strings can be assembled and decrypted, ultimately merging into meaningful textual content. This study promotes the synthesis and multifunctional application of bimetallic nanomaterials, providing innovative solutions to enhance the sensing sensitivity of electrochemical immunosensors and paving the way for advancements in molecular digitization.

3.
J Thorac Dis ; 16(8): 5274-5284, 2024 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-39268132

RESUMEN

Background: There is a shortage of reliable predictive models to provide valuable prognostic information for early esophageal squamous cell carcinoma (ESCC) without lymph node metastasis (LNM). We aimed to develop and validate a nomogram using the prognostic factors in T1N0 ESCC patients. Methods: Patients with pathological T1N0 ESCC who underwent esophagectomy between 2014 and 2021 at three institutes were reviewed. The prognostic factors were evaluated by Cox proportional hazards model and a nomogram was developed. Patients were divided into high- and low-risk groups based on cut-off value of total points in the nomogram. Overall survival (OS) was estimated by the Kaplan-Meier method and compared using the log-rank test. Results: A total of 275 patients were included and split into training (n=180) and external validation (n=95) cohorts. In the training cohort, multivariable analysis showed that the surgical approach, T1 substage, and carcinoembryonic antigen (CEA) level were independent prognostic factors. The developed nomogram had relatively high performance, with the area under the receiver operating characteristic (ROC) curve (AUC) of 0.783, 0.711 and 0.612 for 1-, 3-, and 5-year OS, respectively. The calibration curves showed that the predicted probability was in good agreement with the actual probability. Forty-seven was determined as cut-off value of total points. High-risk group (n=148) showed a significant poor OS than low-risk group (n=127) (P<0.001). Conclusions: Left surgical approach, stage T1b, and higher CEA were associated with poorer prognosis in T1N0 ESCC patients. The nomogram demonstrated a good performance to predict the individual survival.

4.
J Agric Food Chem ; 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39269321

RESUMEN

Five new sorbicillinoid derivatives, including (±)-aspersorbicillin A [(±)-1], a pair of enantiomers at C-9, and aspersorbicillins B-D (2-4), together with two known analogs (5 and 6) were isolated from the endophytic fungus Aspergillus aculeatus TE-65L. Their structures including absolute configurations were determined by detailed spectroscopic analyses and electronic circular dichroism calculations. The herbicidal activity of sorbicillinoids on the germ and radicle elongation of various weed types was reported for the first time. Compound 1 displayed significant herbicidal activity against Eleusine indica germ elongation (IC50 = 28.8 µg/mL), while compound 6 inhibited radicle elongation (IC50 = 25.6 µg/mL). Both were stronger than those of glyphosate (66.2 and 30.9 µg/mL, respectively). Further transcriptomic and LC-MS/MS metabolomic analysis indicated that 6 induced the transcriptional expressions of genes related to the lignin biosynthetic pathway, resulting in lignin accumulation. Transmission electron microscopy confirmed the cell wall thickening of seeds treated with 6, suggesting weed growth inhibition. This study reveals new lead compounds for fabricating natural herbicides and expands the agricultural use of sorbicillinoid analogs.

5.
Food Chem X ; 23: 101652, 2024 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-39113744

RESUMEN

To instruct the production of millet porridge, the effect of cooking methods on flavor and texture of millet porridge was investigated. A total of 91 volatiles were detected and most volatile compounds decreased with cooking time, e.g. alcohols. The esters as major volatiles had a high content in electric rice cooker (IC). Multiple chemometric results indicated that volatiles from different cooking methods were distinguished respectively. Texture analysis indicated that the hardness of millet porridge prepared in IC had a more dominant decrease trend than electromagnetic oven and the electric pressure cooker before 40 min. In conclusion, different cooking methods had a more significant influence on the volatiles than cooking time, while the texture is opposite. The comprehensive sensory score reached its peak in IC-30 min. The comprehensive sensory scores of IC and EC decreased with the prolongation of cooking time. This study helps to improve the sensory attributes of millet porridge.

6.
Front Public Health ; 12: 1424791, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39091519

RESUMEN

Background: As China rapidly ages, it has now become a deeply aging society with the largest number of older individuals in the world. The issue is particularly severe in rural areas. With the aging population growing and the older population expanding, health problems are becoming more prevalent among older individuals, particularly frailty and cognitive impairments. This study aimed to identify the profiles of physical frailty, social frailty, and cognitive impairment among older adults and explore the influencing factors. Methods: In this cross-sectional study, participants were recruited from six villages in four cities in Shandong Province, China from July to October 2023 through cluster random sampling. Latent profile analysis was used to determine the profiles of physical frailty, social frailty, and cognitive impairment. Chi-square tests and Mann-Whitney U tests were used for univariate analysis, while binary logistic regression was used to analyze the related factors. Results: Seven hundred and sixty-nine older adult care in rural areas showed two profiles: the "high cognitive function and low frailty" group (73.7%, n = 567) and the "low cognitive function and high frailty" group (26.3%, n = 202). A binary logistic regression found that older people were more likely to be aged 80 or older (OR = 2.253, p = 0.029), have a low income level (OR = 1.051, p = 0.007), have one or two (OR = 2.287, p = 0.004), or more than three chronic diseases (OR = 3.092, p = 0.002), and report moderate (OR = 3.406, p = 0.024) or poor health status (OR = 9.085, p < 0.001) in the "low cognitive function and high frailty" group. Meanwhile, older adults who have completed high school (OR = 0.428, p = 0.005) or junior college and above (OR = 0.208, p = 0.009), and engage in adequate physical activity (OR = 0.319, p < 0.001) were more likely to be in the "high cognitive function and low frailty" group. Conclusion: In the future, medical professors should increasingly prioritize promptly identifying and intervening in cognitive decline and frailty status in older individuals without delay.


Asunto(s)
Disfunción Cognitiva , Fragilidad , Población Rural , Humanos , China/epidemiología , Masculino , Femenino , Disfunción Cognitiva/epidemiología , Estudios Transversales , Anciano , Población Rural/estadística & datos numéricos , Anciano de 80 o más Años , Fragilidad/epidemiología , Anciano Frágil/estadística & datos numéricos , Evaluación Geriátrica/estadística & datos numéricos , Persona de Mediana Edad
7.
Anal Chim Acta ; 1319: 342980, 2024 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-39122289

RESUMEN

The traditional preparation method of ratiometric probes faces challenges such as cumbersome preparation and low sensitivity. Thus, there is an urgent need to provide a simple method of preparing a highly sensitive ratiometric probe. Here, Eu3+-doped zinc-based organic framework (Eu/Zn-MOF) was prepared through hydrothermal method for the detection of tetracycline analogs (TCs). Under the same excitation conditions, the probe can simultaneously display valuable fluorescence and second-order scattering signals. The developed probe enabled specific identification and fast detection (1 min) of TCs, including tetracycline, oxytetracycline, doxycycline, and chlortetracycline. The linear detection ranges of tetracycline, oxytetracycline, doxycycline and chlortetracycline were respectively 100 nM - 200 µM, 100 nM - 200 µM, 98 nM - 195 µM, and 97 nM - 291 µM, and the corresponding detection limits were respectively 15.79 nM, 20.83 nM, 15.31 nM, and 28.30 nM. The developed sensor was successfully applied to detect TCs in real samples, and the recovery rate was from 92.54 % to 109.69 % and the relative standard deviation was from 0.04 % to 2.97 %. Moreover, the heterometallic Eu/Zn-MOF was designed as a ratiometric neuron for Boolean logic computing and information encryption based on the specific identification of TCs. As a proof of concept, molecular steganography was successfully employed to encode, store, and conceal information by transforming the specific identification patterns of Eu/Zn-MOF into binary strings. This study is anticipated to advance the application of metal-organic frameworks in logic detection and information security, and bridging the gap between molecular sensors and the realm of information.


Asunto(s)
Europio , Estructuras Metalorgánicas , Espectrometría de Fluorescencia , Zinc , Estructuras Metalorgánicas/química , Europio/química , Zinc/química , Zinc/análisis , Colorantes Fluorescentes/química , Colorantes Fluorescentes/síntesis química , Tetraciclinas/análisis , Límite de Detección , Antibacterianos/análisis , Tetraciclina/análisis , Fluorescencia
8.
Anal Chem ; 96(36): 14471-14479, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39185581

RESUMEN

The spatial constraints imposed by the DNA structure have significant implications for the walking efficiency of three-dimensional DNA walkers. However, accurately quantifying and manipulating steric hindrance remains a challenging task. This study presents a steric hindrance-controlled DNA walker utilizing an enzymatic strand displacement amplification (ESDA) strategy for detecting microRNA-21 (miR-21) with tunable dynamic range and sensitivity. The steric hindrance of the DNA walker was precisely manipulated by varying the length of empty bases from 6.5 Što 27.4 Šat the end of the track strand and adjusting the volumetric dimensions of the hairpin structure from 9.13 nm3 to 26.2 nm3 at the terminus of the single-foot DNA walking strand. This method demonstrated a tunable limit of detection for miR-21 ranging from 3.6 aM to 35.6 nM, along with a dynamic range from ∼100-fold to ∼166 000-fold. Impressively, it exhibited successful identification of cancer cells and clinical serum samples with high miR-21 expression. The proposed novel strategy not only enables tunable detection of miRNA through the regulation of steric hindrance but also achieves accurate and quantitative analysis of the steric hindrance effect, promising broader applications in personalized medicine, early disease detection, and drug development.


Asunto(s)
ADN , MicroARNs , Técnicas de Amplificación de Ácido Nucleico , MicroARNs/análisis , MicroARNs/sangre , Humanos , ADN/química , Límite de Detección , Técnicas Biosensibles
9.
Sci Total Environ ; 951: 175423, 2024 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-39134267

RESUMEN

Ecological drought is a complex process in terrestrial ecosystems where vegetation's eco-physiological functions are impaired due to water stress. However, there is currently a lack of long-term assessment of ecological drought from an eco-physiological perspective. In this study, the standardized ecological drought index (SESNDI) was developed using actual evaporation, root soil moisture, and kernel normalized difference vegetation index via the Euclidean distance method, reflecting ecosystem physiology, water supply capacity, and vegetation status. Solar-induced chlorophyll fluorescence validated SESNDI by reflecting vegetation photosynthesis. Using China as an example, severely impacted by climate change and ecological restoration, ecological drought's spatio-temporal variation and propagation characteristics was evaluated using clustering algorithms. The results demonstrated that (1) SESNDI showed superior performance over several other drought indices. (2) During 1982-2020, ecological drought was prevalent from 1990 to 2010, especially in the central and northeastern regions. (3) Compared to 1982-2000, the median duration and affected area of ecological drought events during 2001-2020 reduced by four months and 1.51 × 105 km2, respectively, while the median intensity increased by 0.06. (4) Decreased precipitation and increased temperature were the primary factors contributing to the frequent occurrence of ecological drought in China from 1990 to 2010. This study offers a crucial methodology for evaluating ecological drought, serving as a reference for developing effective terrestrial restoration strategies.


Asunto(s)
Cambio Climático , Sequías , Ecosistema , Monitoreo del Ambiente , China , Monitoreo del Ambiente/métodos
10.
Chemosphere ; 364: 143153, 2024 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-39197682

RESUMEN

Polypropylene microplastics (PP-MPs), an emerging pollutant, adversely affect the ability of aquatic plants to restore water bodies, thereby compromising the functionality and integrity of wetland ecosystems. This study examines the effects of microplastic stress on the nitrogen and phosphorus removal capacities of Acorus calamus and Iris tectorum, as well as on functional microorganisms within the aquatic system. The findings indicate that under PP-MP stress, the nitrogen and phosphorus absorption capabilities of both plants were diminished. Additionally, there was a significant reduction in the metabolic enzyme activities related to nitrogen and phosphorus in the plants, alongside a notable decrease in leaf nitrogen content. PP-MPs hinder the nutrient uptake of plants, affecting their growth and indirectly reducing their ability to utilize nitrogen and phosphorus. Specifically, in the 10 mg L-1 treatment group, A. calamus and I. tectorum showed reductions in leaf nitrogen content by 23.1% and 31.0%, respectively, and by 14.8% and 27.7% in the 200 mg L-1 treatment group. Furthermore, I. tectorum had higher leaf nitrogen levels than A. calamus. Using fluorescent tagging, the distribution of PP-MPs was traced in the roots, stems, and leaves of the plants, revealing significant growth impairment in both species. This included a considerable decline in photosynthetic pigment synthesis, enhanced oxidative stress responses, and increased lipid peroxidation in cell membranes. PP-MP exposure also significantly reduced the abundance of functional microorganisms involved in denitrification and phosphorus removal at the genus level in aquatic systems. Ecological function predictions revealed a notable decrease in nitrogen cycling functions such as nitrogen respiration and nitrite denitrification among water microorganisms in both treatment groups, with a higher ecological risk potential in the A. calamus treatment group. This study provides new insights into the potential stress mechanisms of PP-MPs on aquatic plants involved in water body remediation and their impacts on wetland ecosystems.

11.
Toxicon ; 247: 107849, 2024 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-38971474

RESUMEN

Mushroom poisoning is a significant contributor to foodborne disease outbreaks in China. This study focuses on two Panaeolus subbalteatus poisoning incidents accompanied by epidemiological investigations, species identification, and toxin detection in Ningxia, northwest China. In these two poisoning incidents, some patients exhibited gastrointestinal or neurological symptoms approximately 0.5 h after ingestion of a large amount of wild mushroom. Specifically, in Case 1, one of the three patients experienced nausea, vomiting, and numbness in the throat and limbs; in Case 2, one patient reported dizziness and an abnormal sense of direction. Through morphological and phylogenetic analyses, mushroom specimens were identified as P. subbalteatus. Psilocybin and psilocin were detected in mushroom samples, and only psilocin was detected in biological samples by liquid chromatography-triple quadrupole-linear ion trap mass spectrometry screening. The average psilocybin and psilocin contents in mushroom samples were 1532.2-1760.7 and 114.5-136.0 mg/kg (n = 3), respectively. Moreover, only psilocin was detected in blood and urine samples, with average concentrations 0.5-1.2 ng/mL (n = 3) and 2.5-3.1 ng/mL (n = 3), respectively. These findings provide technical support for managing similar incidents in the future.


Asunto(s)
Intoxicación por Setas , Psilocibina , Intoxicación por Setas/diagnóstico , China , Psilocibina/análogos & derivados , Humanos , Triptaminas/análisis , Masculino , Adulto , Femenino , Filogenia , Persona de Mediana Edad
12.
Talanta ; 278: 126526, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-38996564

RESUMEN

Understanding charge transport in metal ion-mediated glutathione-stabilized gold nanoclusters (GSH-Au NCs) has proved difficult due to the presence of various competitive mechanisms, such as electron transfer (ET) and aggregation induction effect (AIE). In this paper, we present a dual-channel fluorescence (FL) and second-order Rayleigh scattering (SRS) sensing method for high-throughput classification of metal ions, relying on the competition between ET and AIE using GSH-Au NCs. The SRS signals show significant enhancement when Pb2+, Ag+, Al3+, Cu2+, Fe3+, and Hg2+ are present, as a result of the aggregation of GSH-Au NCs. Notably, the fluorescence signal exhibits the opposite trend. The FL intensities of GSH-Au NCs are enhanced by Pb2+, Ag+, and Al3+ through the AIE mechanism, while they are quenched by Cu2+, Fe3+, and Hg2+, which is dominated by the ET mechanism. By employing principal component analysis and hierarchical cluster analysis, these signals are transformed into unique fingerprints and Euclidean distances, respectively, enabling successful distinction of six metal ions and their mixtures with a low detection limit of 30 nM. This new strategy has successfully addressed interference from impurities in the testing of real water samples, demonstrating its strong ability to detect multiple metal ions. Impressively, we have achieved molecular cryptosteganography, which involves encoding, storing, and concealing information by transforming the selective response of GSH-Au NCs to binary strings. This research is anticipated to advance utilization of nanomaterials in logic sensing and information safety, bridging the gap between molecular sensors and information systems.

13.
Food Chem X ; 22: 101515, 2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-38883914

RESUMEN

To investigate the optimal processing of maize porridge, the volatile compounds and texture under different cooking methods and time have been studied. A total of 51 volatile compounds were identified in maize porridge. Notably, the major volatiles, aldehydes and esters exhibited a relatively high content in electric pressure cooker (EPC), and esters tend to significantly increase after cooking. Among aldehydes, nonanal and hexanal played a great role in flavor due to their relatively high content. Volatile compounds of maize porridge in different cooking methods could be clearly distinguished by multiple chemometrics. Furthermore, texture analysis revealed that almost all the indicators in the EPC can reach the lowest value at 60 min. To summarize, different cooking methods had a more significant influence on the volatile compounds and texture compared to time. This study helps to improve the sensory attributes of maize porridge, and thus contributes to healthier and more sustainable production.

14.
BMC Public Health ; 24(1): 1465, 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38822295

RESUMEN

BACKGROUND: Malnutrition is related to impaired oral health and function that causes poor dietary intake, declining the general health of older adults. The role of dietary intake in the association between oral function and nutritional status of Chinese older adults (aged 75 and above) was examined in this cross-sectional study. METHODS: Through the randomized cluster sampling method, 267 older adults living in rural areas of Qingdao, Shandong (aged 81.4 ± 4.3, 75-94 years) were chosen as the primary research participants. A Mini Nutritional Assessment - Short Form was used to determine nutritional status, and Food Frequency Questionnaire and 24-hour Food Intake Recall were used to assess dietary intake. The oral function was evaluated by analyzing the teeth, oral problems, bite force, tongue pressure, lip sealing pressure, chewing function questionnaire, whole saliva flow rate, 10-Item Eating Assessment Tool, and water swallow test. RESULTS: Based on the MNA-SF score, it was divided into a well-nourished group and a malnutrition group, with the malnutrition group comprising 40.6% of participants. The participants in the malnutrition group showed a higher rate of xerostomia, lower bite force, tongue pressure, and lip sealing pressure, and higher Chewing Function Questionnaire and 10-Item Eating Assessment Tool scores. Furthermore, their plant fat, iron, cereals and potatoes, vegetables, fruits, and seafood intake were relatively low. The regression model indicated that exercise frequency, stroke, chewing and swallowing function, intake of vegetables and fruits were risk factors for nutritional status of older adults. CONCLUSION: Malnutrition was relatively common among the Chinese older adults aged 75 and above, and it was significantly correlated with exercise frequency, stroke, chewing and swallowing function, and intake of vegetables and fruits. Therefore, nutrition management should be carried out under the understanding and guidance of the oral function and dietary intake of the older adults.


Asunto(s)
Estado Nutricional , Humanos , Estudios Transversales , Anciano , Masculino , Femenino , Anciano de 80 o más Años , China/epidemiología , Desnutrición/epidemiología , Salud Bucal/estadística & datos numéricos , Dieta/estadística & datos numéricos , Ingestión de Alimentos/fisiología , Encuestas y Cuestionarios , Evaluación Nutricional
15.
Anal Chim Acta ; 1298: 342407, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38462332

RESUMEN

The accurate diagnosis of diseases can be improved by detecting multiple biomarkers simultaneously. This study presents the development of a magnetic photoelectrochemical (PEC) immunosensor array for the simultaneous detection of amyloid-ß 42 (Aß) and microtubule-associated protein (Tau), which are markers for neurodegenerative disorders. A metal-organic framework (MOF) derivative, Fe2O3@FeS2 magnetic composites with exceptional photoelectric and ferromagnetic properties was synthesized while preserving the original structure and advantages. Thus, the immunoassembly process of the sensor can be carried out in homogeneous solution and recovered by magnetic separation. For simultaneous detection, a chip is divided into multiple independent sensing sites, which have the same preparation and detection environment, allowing for the implementation of a self-calibration method. The sensor array demonstrates considerable detection ranges of 0.01-100 ng mL-1 for Aß and 0.05-100 ng mL-1 for Tau, with low detection limits of 2.1 pg mL-1 for Aß and 7.9 pg mL-1 for Tau. The PEC sensor array proposed in this study exhibits exceptional stability, selectivity, and reproducibility, providing a new method for detecting multiple markers.


Asunto(s)
Técnicas Biosensibles , Técnicas Biosensibles/métodos , Reproducibilidad de los Resultados , Inmunoensayo/métodos , Péptidos beta-Amiloides , Fenómenos Magnéticos , Técnicas Electroquímicas/métodos , Límite de Detección
16.
Ecotoxicol Environ Saf ; 274: 116210, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38479311

RESUMEN

Thiosulfate influences the bioreduction and migration transformation of arsenic (As) and iron (Fe) in groundwater environments. The aim of this study was to investigate the impact of microbially-mediated sulfur cycling on the bioreduction and interaction of As and Fe. Microcosm experiments were conducted, including bioreduction of thiosulfate, As(V), and Fe(III) by Citrobacter sp. JH012-1, as well as the influence of thiosulfate input at different initial arsenate concentrations on the bioreduction of As(V) and Fe(III). The results demonstrate that Citrobacter sp. JH012-1 exhibited strong reduction capabilities for thiosulfate, As(V), and Fe(III). Improving thiosulfate level promoted the bioreduction of Fe(III) and As(V). When 0, 0.1, 0.5, and 1 mM thiosulfate were added, Fe(III) was completely reduced within 9 days, 3 days, 1 day, and 0.5 days, simultaneously, 72.8%, 82.2%, 85.5%, and 90.0% of As(V) were reduced, respectively. The products of As(III) binding with sulfide are controlled by the ratio of As-S. When the initial arsenate concentration was 0.025 mM, the addition of thiosulfate resulted in the accumulation of soluble thioarsenite. However, when the initial arsenate level increased to 1 mM, precipitates of orpiment or realgar were formed. In the presence of both arsenic and iron, As(V) significantly inhibits the bioreduction of Fe(III). Under the concentrations of 0, 0.025, and 1 mM As(V), the reduction rates of Fe(III) were 100%, 91%, and 83%, respectively. In this scenario, the sulfide produced by thiosulfate reduction tends to bind with Fe(II) rather than As(III). Therefore, the competition of arsenic-iron and thiosulfate concentration should be considered to study the impact of thiosulfate on arsenic and iron migration and transformation in groundwater.


Asunto(s)
Arsénico , Agua Subterránea , Hierro/análisis , Arsénico/metabolismo , Arseniatos , Tiosulfatos , Oxidación-Reducción , Sulfuros , Compuestos Férricos/metabolismo
17.
Talanta ; 272: 125780, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38359722

RESUMEN

Mercury ion (Hg2+) poses a serious threat to human health due to its high toxicity. In this study, a smartphone-based photoelectrochemical sensor based on oxygen vacancies (OVs) driven signal enhancement for mercury ion detection was designed. BiVO4-x/Bi2S3/AuNPs were combined with T-Hg2+-T recognition mode to construct a multi-sandwich photoelectrochemical sensor. On the one hand, the OVs can increase the adsorption of light by the materials and enhance the photocurrent response as well as the superconductivity of Au NPs to accelerate the charge transfer at the electrode interface. On the other hand, the multi-sandwich structure was exploited to increase the binding site of Hg2+, as well as the T-Hg2+-T structure for sensitive recognition of Hg2+ and signal amplification. The sensor showed good linearity for Hg2+ concentration in the range of 0.1 nM-1.0 µM with a detection limit of 4.8 pM (S/N = 3). Eventually the smartphone-based real-time detection sensor is expected to contribute to the future analysis of heavy metal ions.

18.
Anal Chem ; 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38324019

RESUMEN

Cascade molecular events in complex systems are of vital importance for enhancing molecular diagnosis and information processing. However, the conversion of a cascaded biosensing system into a multilayer encrypted molecular keypad lock remains a significant challenge in the development of molecular logic devices. In this study, we present a photocleavable DNA nanotube-based dual-amplified resonance Rayleigh scattering (RRS) system for detecting microRNA-126 (miR-126). The cascading dual-amplification biosensing system provides a multilayer-encrypted prototype with the functionality of a molecular computing cascade keypad lock. RRS signals were greatly amplified by using photocleavable DNA nanotubes and enzyme-assisted strand displacement amplification (SDA). In the presence of miR-126, enzyme-assisted SDA produced numerous identical nucleotide fragments as the target, which were then specifically attached to magnetic beads through the DNA nanotube by using a Y-shaped DNA scaffold. Upon ultraviolet irradiation, the DNA nanotube was released into the solution, resulting in an increase in the intensity of the RRS signal. This strategy demonstrated a low limit of detection (0.16 fM) and a wide dynamic range (1 fM to 1 nM) for miR-126. Impressively, the enzyme-assisted SDA offers a molecular computing model for generating the target pool, which serves as the input element for unlocking the system. By cascading the molecular computing process, we successfully constructed a molecular keypad lock with a multilevel authentication technique. The proposed system holds great potential for applications in molecular diagnosis and information security, indicating significant value in integrating molecular circuits for intelligent sensing.

19.
Mol Pharm ; 21(3): 1300-1308, 2024 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-38294949

RESUMEN

Keratin and lipid structures in the stratum corneum (SC) are closely related to the SC barrier function. The application of penetration enhancers (PEs) disrupts the structure of SC, thereby promoting infiltration. To quantify these PE-induced structural changes in SC, we used confocal Raman imaging (CRI) and polarized Raman imaging (PRI) to explore the integrity and continuity of keratin and lipid structures in SC. The results showed that water is the safest PE and that oleic acid (OA), sodium dodecyl sulfate (SDS), and low molecular weight protamine (LMWP) disrupted the ordered structure of keratin, while azone and liposomes had less of an effect on keratin. Azone, OA, and SDS also led to significant changes in lipid structure, while LMWP and liposomes had less of an effect. Establishing this non-invasive and efficient strategy will provide new insights into transdermal drug delivery and skin health management.


Asunto(s)
Liposomas , Piel , Liposomas/farmacología , Epidermis , Ácido Oléico/farmacología , Queratinas
20.
Talanta ; 270: 125559, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38141465

RESUMEN

The chemical composition and structure of the stratum corneum (SC) play a crucial role in the skin barrier function. Therefore, accurately determining the SC thickness and studying the changes in lipid and keratin structure and distribution within it are key aspects of skin barrier research. Currently, there are limited analytical tools and data analysis methods available for real-time and online studies of SC composition and structural changes. In this study, we focus on depth as a perturbation and employ confocal Raman microscopy combined with moving-window two-dimensional correlation spectroscopy (MW2D) technique to investigate the SC thickness. Additionally, we employ confocal Raman microscopy combined with perturbation-correlation moving-window two-dimensional correlation spectroscopy (PCMW2D) to precisely characterize the stratification of the SC. Furthermore, the two-dimensional correlation spectroscopy (2DCOS) method is utilized to examine the content of various conformations in the keratin secondary structure within the SC, as well as the subtle interrelationships between lipid and keratin structures.


Asunto(s)
Epidermis , Espectrometría Raman , Espectrometría Raman/métodos , Microscopía Confocal/métodos , Queratinas , Lípidos , Piel
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA