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1.
Talanta ; 282: 127033, 2024 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-39406082

RESUMO

MicroRNAs (miRNAs) are closely associated with cancer and have been considered cancer biomarkers. Herein, we propose an electrochemiluminescence (ECL) biosensor for detecting miRNA-21 based on target-induced catalytic hairpin self-assembly (CHA) and CuO-mediated azide-alkyne cycloaddition. Two hairpin DNAs were employed: one was immobilized on magnetic beads (HP2) and another was labeled with CuO (HP1-CuO). HP1 and HP2 formed a duplex through CHA induced by miRNA-21, resulting in the immobilization of CuO on magnetic beads and in the recycling of miRNA-21. After magnetic separation, CuO was treated with hydrochloric acid to release Cu2+, which concentration is quantitatively proportional to the target concentration. Subsequently, Cu2+ was reduced to Cu+, which catalyzed the click reaction between Fc-C CH and SH-DNA-N3+ immobilized on a Au/g-C3N4 modified electrode. Thus, the ECL of Au/g-C3N4 was quenched by Fc, and miRNA-21 was indirectly detected through a change in ECL intensity. Benefiting from the amplification effect of CuO nanoparticle loading, CHA-based target recycling, and the catalytic effect of click reaction, the proposed ECL biosensor showed high sensitivity. Experimental results indicate that the ECL biosensor proposed for detecting miRNA-21 exhibits a wide linear range from 1 fM to 1 nM and a low detection limit of 0.26 fM (3σ/S). Furthermore, the ECL sensor was capable of measuring miRNA-21 in real serum with high selectivity, indicating its notable applicable potential in biomedicine and clinical diagnosis.

2.
Materials (Basel) ; 17(20)2024 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-39459695

RESUMO

Developing an OER electrocatalyst that balances high performance with low cost is crucial for widely adopting PEM water electrolyzers. Ru-based catalysts are gaining attention for their cost-effectiveness and high activity, positioning them as promising alternatives to Ir-based catalysts. However, Ru-based catalysts can be prone to oxidation at high potentials, compromising their durability. In this study, we utilize a simple synthesis method to synthesize a SnO2, Nb2O5, and RuO2 composite catalyst (SnO2/Nb2O5@RuO2) with multiple interfaces and abundant oxygen vacancies. The large surface area and numerous active sites of the SnO2/Nb2O5@RuO2 catalyst lead to outstanding acidic oxygen evolution reaction (OER) performance, achieving current densities of 10, 50, and 200 mA cm-2 at ultralow overpotentials of 287, 359, and 534 mV, respectively, significantly surpassing commercial IrO2. Moreover, incorporating Nb2O5 into the SnO2/Nb2O5@RuO2 alters the electronic structure at the interfaces and generates a high density of oxygen vacancies, markedly enhancing durability. Consequently, the membrane electrode composed of SnO2/Nb2O5@RuO2 and commercial Pt/C demonstrated stable operation in the PEM cell for 25 days at an industrial current density of 1 A cm-2. This research presents a convenient approach for developing a highly efficient and durable Ru-based electrocatalyst, underscoring its potential for proton exchange membrane water electrolysis.

3.
Phys Chem Chem Phys ; 26(42): 27106-27115, 2024 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-39431706

RESUMO

Numerous boron-based molecular fluxional models, such as the Wankel motor, tank treads B11- and B10C, and the Earth-Moon system Be6B11-, have been widely recognized for their potential to develop molecular machines. From a series of tin-doped boron clusters SnBn- (n = 5-14), the half-sandwich structure SnB7- is found to possess high relative energy stability, and a HOMO-LUMO gap of 4.33 eV. This structure exhibits valence electron orbitals reminiscent of σ-π double aromatic compounds. The incorporation of tin effectively fills the doubly vacant π orbitals of its parent triplet B7-, thereby enhancing both magnetic shielding capabilities and range. Thermal bath tests demonstrate its significant dynamic stability, as the kinetic energy provided by thermal baths below 3800 K remains insufficient to disrupt its inherent elasticity. Additionally, transition state searches and intrinsic reaction coordinate analyses confirm that the tin atom migrates from the centre to the edge of the boron ligand surface, a phenomenon that can be observed in high-temperature thermal bath simulations. This fluxional behaviour provides insights for constructing novel molecular machine models.

4.
Food Chem X ; 23: 101713, 2024 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-39239532

RESUMO

To examine flavor variations in Xuanwei ham due to different cooking methods, we selected one-year cured Xuanwei ham and applied four techniques: dry frying (DF), baking (BA), steaming (ST), and boiling (BO). Organoleptic evaluation revealed ST received the highest overall sensory score. High-performance liquid chromatography (HPLC) revealed that the total nucleotide content was significantly different (P < 0.05), lactic acid predominated the measured organic acids. Solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) and chromatography-electronic nose (GC-E-Nose) data indicated that ST resulting in significantly higher total volatile compounds than the other methods (P < 0.05). SPME-GC-MS detected 55 volatile compounds, and 12 characteristic flavor substances were identified using orthogonal partial least squares discriminant analysis (OPLS-DA) (VIP > 1). This study aimed to support comprehensive research on the flavor characteristics of cooked Xuanwei ham and guide the selection of appropriate processing methods.

5.
Artigo em Inglês | MEDLINE | ID: mdl-39255125

RESUMO

We introduce a visual analysis method for multiple causal graphs with different outcome variables, namely, multi-outcome causal graphs. Multi-outcome causal graphs are important in healthcare for understanding multimorbidity and comorbidity. To support the visual analysis, we collaborated with medical experts to devise two comparative visualization techniques at different stages of the analysis process. First, a progressive visualization method is proposed for comparing multiple state-of-the-art causal discovery algorithms. The method can handle mixed-type datasets comprising both continuous and categorical variables and assist in the creation of a fine-tuned causal graph of a single outcome. Second, a comparative graph layout technique and specialized visual encodings are devised for the quick comparison of multiple causal graphs. In our visual analysis approach, analysts start by building individual causal graphs for each outcome variable, and then, multi-outcome causal graphs are generated and visualized with our comparative technique for analyzing differences and commonalities of these causal graphs. Evaluation includes quantitative measurements on benchmark datasets, a case study with a medical expert, and expert user studies with real-world health research data.

7.
J Comput Chem ; 45(31): 2678-2689, 2024 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-39135268

RESUMO

The two-dimensional (2D) monolayer material MoSi2N4 was successfully synthesized in 2020[Hong et al., Science 369, 670, (2020)], exhibiting a plethora of new phenomena and unusual properties, with good stability at room temperature. However, MA2Z4 family monolayer materials involve primarily transition metal substitutions for M atoms. In order to address the research gap on lanthanide and actinide MA2Z4 materials, this work conducts electronic structure calculations on novel 2D MSi2N4 (M = La, Eu) monolayer materials by employing first-principles methods and CASTEP. High carrier mobility is discovered in the indirect bandgap semiconductor 2D LaSi2N4 monolayer (~5400 cm2 V-1 s-1) and in the spin (spin-down channel) carrier mobility of the half-metallic ferromagnetic EuSi2N4 monolayer (~2800 cm2 V-1 s-1). EuSi2N4 monolayer supplements research on spin carrier mobility in half-metallic ferromagnetic monolayer materials at room temperature and possesses a magnetic moment of 5 µB, which should not be underestimated. Furthermore, due to the unique electronic band structure of EuSi2N4 monolayer (with the spin-up channel exhibiting metallic properties and the spin-down channel exhibiting semiconductor properties), it demonstrates a 100% spin polarization rate, presenting significant potential applications in fields such as magnetic storage, magnetic sensing, and spintronics.

8.
Toxicology ; 508: 153924, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39147091

RESUMO

Nicotine, the primary constituent of tobacco, is one of the important factors that induce the occurrence of hepatocellular carcinoma (HCC). The ß2-adrenergic receptor (ß2-AR) is implicated in the growth and advancement of tumors. However, the role of ß2-AR and its mediated cascades in nicotine-induced HCC remains unclear. This present study aims to observe the effects of nicotine on the proliferation, migration, and invasion of immortalized human liver epithelial (THLE-2) cells, as well as to explore the underlying mechanisms of action. The results of cell counting kit-8 (CCK-8) assay showed that 0.3125 µM nicotine had the ability to promote the proliferation of THLE-2 cells with a significant time-dependent manner. Therefore, THLE-2 cells were mainly selected for chronic treatment with 0.3125 µM nicotine in the later stage to cause transformation. After 30 passages of THLE-2 cells with 0.3125 µM nicotine treatment, chronic exposure to nicotine significantly enhanced the proliferation, metastasis, and invasion of cells. Besides, it also upregulated the intracellular levels of ß2-AR, phosphoinositide 3-kinase (PI3K), AKT, matrix metalloproteinase-2 (MMP-2) and Cyclin D1, as well as downregulated the expression of p53. More importantly, the ß2-AR/PI3K/AKT pathway was found to mediate the expression of MMP-2, Cyclin D1, and p53 in THLE-2 cells, playing a crucial role in their proliferation, migration, and invasion after continuous exposure to nicotine. Simply put, it demonstrated the role of ß2-AR/PI3K/AKT pathway in the transformation of THLE-2 cells induced by nicotine. This study could provide valuable insights into the relationship between nicotine and HCC. Additionally, it lays the groundwork for investigating potential anticancer treatments for liver cancer linked to tobacco consumption.


Assuntos
Movimento Celular , Proliferação de Células , Nicotina , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Receptores Adrenérgicos beta 2 , Transdução de Sinais , Nicotina/toxicidade , Nicotina/farmacologia , Humanos , Proliferação de Células/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Movimento Celular/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Receptores Adrenérgicos beta 2/metabolismo , Receptores Adrenérgicos beta 2/efeitos dos fármacos , Linhagem Celular , Invasividade Neoplásica , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/metabolismo , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/induzido quimicamente , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/patologia
9.
ACS Omega ; 9(32): 35197-35208, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39157101

RESUMO

A series of minimally sized regular dodecahedron-embedded metallofullerene REC20 clusters (RE = Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, and Gd) as basic units of nanoassembled materials with tunable magnetism and UV sensitivity have been explored using density functional theory (DFT). The contribution of the 4f orbital of the rare earth atom at the center of the C20 cage to the frontier molecular orbital of REC20 gives the REC20 cluster additional stability. The AdNDP orbitals of the four REC20 superatoms that conform to the spherical jellium model indicate that through natural population analysis and spin density diagrams, we observe a monotonic increase in the magnetic moment from Ce to Gd. This is attributed to the increased number of unpaired electrons in the 4f orbitals of lanthanide rare earth atoms. The UV-visible spectrum of REC20 clusters shows strong absorption in the mid-UV and near-UV bands. REC20 clusters encapsulating lanthanide rare earth atoms stand out for their tunable magnetism, UV sensitivity, and stability, making them potential new self-assembly materials.

10.
Vaccines (Basel) ; 12(8)2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-39204046

RESUMO

The 20 µg (0-1-6 month) hepatitis B virus (HBV) vaccination is widely recommended for HBV vaccine-naïve immune adults in China. However, suboptimal protective responses may occur due to dose-series incompletion. We aim to investigate the immunogenicity of a 60 µg HB vaccine with a 0-2 month series among HBV vaccine-naïve immune adults aged 25-55 to assess potential alternative approaches for HB immunization. A two-center randomized controlled trial was carried out. Participants were randomly allocated to either the 20 µg (0-1-6 month) or the 60 µg (0-2 month) regimen. Blood samples were collected eight weeks after the final injection to measure the antibodies. A total of 583 adults (289 in the 20 µg regimen and 294 in the 60 µg regimen) were included. The seroprotection rates (SPRs) were 97.23% and 93.54% in the 20 µg and 60 µg regimens, respectively (p = 0.0261), and the geometric mean concentrations were 600.76 mIU/mL and 265.68 mIU/mL, respectively (p < 0.0001). The immunogenicity of the 60 µg regimen decreased significantly with age, particularly in adults aged 40 and older. The 60 µg regimen may be beneficial for adults under 40, especially those with poor compliance or in urgent need of immunization.

11.
J Phys Chem A ; 128(28): 5459-5472, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-38973649

RESUMO

In this study, we employ density functional theory along with the artificial bee colony algorithm for cluster global optimization to explore the low-lying structures of TeBnq (n = 3-16, q = 0, -1). The primary focus is on reporting the structural properties of these clusters. The results reveal a consistent doping pattern of the tellurium atom onto the in-plane edges of planar or quasi-planar boron clusters in the most energetically stable isomers. Additionally, we simulate the photoelectron spectra of the cluster anions. Through relative stability analysis, we identify three clusters with magic numbers -TeB7-, TeB10, and TeB12. The aromaticity of these clusters is elucidated using adaptive natural density partitioning (AdNDP) and magnetic properties analysis. Notably, TeB7- exhibits a perfect σ-π doubly aromatic structure, while TeB12 demonstrates strong island aromaticity. These findings significantly contribute to our understanding of the structural and electronic properties of these clusters.

12.
Molecules ; 29(13)2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38999190

RESUMO

This paper systematically investigates the structure, stability, and electronic properties of niobium carbide clusters, NbmCn (m = 5, 6; n = 1-7), using density functional theory. Nb5C2 and Nb5C6 possess higher dissociation energies and second-order difference energies, indicating that they have higher thermodynamic stability. Moreover, ab initio molecular dynamics (AIMD) simulations are used to demonstrate the thermal stability of these structures. The analysis of the density of states indicates that the molecular orbitals of NbmCn (m = 5, 6; n = 1-7) are primarily contributed by niobium atoms, with carbon atoms having a smaller contribution. The composition of the frontier molecular orbitals reveals that niobium atoms contribute approximately 73.1% to 99.8% to NbmCn clusters, while carbon atoms contribute about 0.2% to 26.9%.

13.
Front Immunol ; 15: 1375013, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39040110

RESUMO

Introduction: Immunotherapy is critical for treating many cancers, and its therapeutic success is linked to the tumor microenvironment. Although anti-angiogenic drugs are used to treat gastric cancer (GC), their efficacy remains limited. Cancer-associated fibroblast (CAF)-targeted therapies complement immunotherapy; however, the lack of CAF-specific markers poses a challenge. Therefore, we developed a CAF angiogenesis prognostic score (CAPS) system to evaluate prognosis and immunotherapy response in patients with GC, aiming to improve patient stratification and treatment efficacy. Methods: We assessed patient-derived GC CAFs for promoting angiogenesis using EdU, cell cycle, apoptosis, wound healing, and angiogenesis analysis. Results: We then identified CAF-angiogenesis-associated differentially-expressed genes, leading to the development of CAPS, which included THBS1, SPARC, EDNRA, and VCAN. We used RT-qPCR to conduct gene-level validation, and eight GEO datasets and the HPA database to validate the CAPS system at the gene and protein levels. Six independent GEO datasets were utilized for validation. Overall survival time was shorter in the high- than the low-CAPS group. Immune microenvironment and immunotherapy response analysis showed that the high-CAPS group had a greater tendency toward immune escape and reduced immunotherapy efficacy than the low-CAPS group. Discussion: CAPS is closely associated with GC prognosis and immunotherapy outcomes. It is therefore an independent predictor of GC prognosis and immunotherapy efficacy.


Assuntos
Fibroblastos Associados a Câncer , Imunoterapia , Neovascularização Patológica , Neoplasias Gástricas , Microambiente Tumoral , Humanos , Neoplasias Gástricas/terapia , Neoplasias Gástricas/imunologia , Neoplasias Gástricas/mortalidade , Fibroblastos Associados a Câncer/metabolismo , Fibroblastos Associados a Câncer/imunologia , Microambiente Tumoral/imunologia , Prognóstico , Imunoterapia/métodos , Neovascularização Patológica/imunologia , Masculino , Feminino , Regulação Neoplásica da Expressão Gênica , Pessoa de Meia-Idade , Biomarcadores Tumorais
14.
Ecotoxicol Environ Saf ; 282: 116686, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38971100

RESUMO

Constituents of cigarette smoke are known to be carcinogens. Additionally, there is mounting evidence that the liver is an organ susceptible to tobacco carcinogenicity. Nicotine, the primary constituent of tobacco, plays a role in cancer progression. In our previous study, it was found that nicotine enhances the proliferation of a human normal fetal hepatic (WRL68) cell due to the activation of p53 mutation at Ser249 (p53-RS)/STAT1/CCND1 signaling pathway. Here, we further elucidated the mechanism of regulating this pathway. Firstly, dose-dependent increase of SETDB1 protein level in WRL68 cells upon exposure to nicotine (1.25, 2.5, and 5 µM), significantly enhanced cellular proliferation. In addition, the upregulation of SETDB1 protein was necessary for the nuclear translocation of p53-RS to establish a ternary complex with STAT1 and SETDB1, which facilitated p53-RS di-methylation at K370 (p53-RS/K370me2). After that, the activation of CCND1/PI3K/AKT pathway was initiated when STAT1 stability was enhanced by p53-RS/K370me2, ultimately resulting in cell proliferation. Altogether, the study revealed that the increase in SETDB1 expression could potentially have a significant impact on the activation of CCND1/PI3K/AKT pathway through p53-RS/K370me2, leading to the proliferation of WRL68 cells induced by nicotine, which could contribute to hepatocellular carcinoma for smokers. Besides, the results of this study provided a foundation for the development of anticancer therapies for cancers associated with tobacco use.


Assuntos
Proliferação de Células , Ciclina D1 , Histona-Lisina N-Metiltransferase , Nicotina , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Transdução de Sinais , Proteína Supressora de Tumor p53 , Humanos , Nicotina/toxicidade , Ciclina D1/metabolismo , Ciclina D1/genética , Histona-Lisina N-Metiltransferase/genética , Proliferação de Células/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Proteína Supressora de Tumor p53/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais/efeitos dos fármacos , Metilação/efeitos dos fármacos , Linhagem Celular , Fator de Transcrição STAT1/metabolismo
15.
Small Methods ; : e2400465, 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39049798

RESUMO

Porous materials are excellent candidates for water remediation in environmental issues. However, it is still a key challenge to design efficient adsorbents for rapid water purification from various heavy metal ions-contaminated wastewater in one step. Here, two robust nitrogen-rich covalent organic frameworks (COFs) bearing terpyridine units on the pore walls by a "bottom-up" strategy are reported. Benefitting from the strong chelation interaction between the terpyridine units and various heavy metal ions, these two terpyridine COFs show excellent removal efficiency and capability for Pb2+, Hg2+, Cu2+, Ag+, Cd2+, Ni2+, and Cr3+ from water. These COFs are shown to remove such heavy metal ions with >90% of contents at one time after the aqueous metal ions mixture is passed through the COF filter. The nitrogen-rich features of the COFs also endow them with the capability of capturing iodine vapors, offering the terpyridine COFs the potential for environmental remediation applications.

16.
Zhongguo Dang Dai Er Ke Za Zhi ; 26(6): 659-664, 2024 Jun 15.
Artigo em Chinês | MEDLINE | ID: mdl-38926385

RESUMO

In infants with severe bronchopulmonary dysplasia (sBPD), severe pulmonary lobar emphysema may occur as a complication, contributing to significant impairment in ventilation. Clinical management of these infants is extremely challenging and some may require lobectomy to improve ventilation. However, prior to the lobectomy, it is very difficult to assess whether the remaining lung parenchyma would be able to sustain adequate ventilation postoperatively. In addition, preoperative planning and perioperative management are also quite challenging in these patients. This paper reports the utility of selective bronchial occlusion in assessing the safety and efficacy of lobectomy in a case of sBPD complicated by severe right upper lobar emphysema. Since infants with sBPD already have poor lung development and significant lung injury, lobectomy should be viewed as a non-traditional therapy and be carried out with extreme caution. Selective bronchial occlusion test can be an effective tool in assessing the risks and benefits of lobectomy in cases with sBPD and lobar emphysema. However, given the technical difficulty, successful application of this technique requires close collaboration of an experienced interdisciplinary team.


Assuntos
Displasia Broncopulmonar , Recém-Nascido Prematuro , Enfisema Pulmonar , Humanos , Recém-Nascido , Brônquios , Displasia Broncopulmonar/etiologia , Pneumonectomia , Enfisema Pulmonar/cirurgia
17.
Health Care Sci ; 3(2): 101-113, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38939613

RESUMO

Background: Although socioeconomic support is recommended for frailty management, its association with the prognosis of frailty is unclear. Methods: Using data from participants aged ≥65 years in the Chinese Longitudinal Healthy Longevity Survey (2008-2018), the associations between socioeconomic support (source of income, medical insurance, community support, living status), onset of prefrailty/frailty, and worsening of prefrailty, were analyzed using multinominal logistic regression models. The associations between self-reported low quality of life (QoL) and reversion of prefrailty/frailty were analyzed using multivariate logistic regression models. Associations with mortality risk were analyzed using Cox proportional hazard regression models. Results: A total of 13,859 participants (mean age: 85.8 ± 11.1 years) containing 2056 centenarians were included. Financial dependence was a risk factor for low QoL among prefrail/frail individuals, but not among robust individuals. Having commercial or other insurance, and receiving social support from the community were protective factors for low QoL among prefrail/frail individuals and for the worsening of prefrailty. Continuing to work was a risk factor for low QoL, but a protective factor for worsening of prefrailty. A negative association between continuing to work and mortality existed in prefrail individuals aged <85 years and ≥85 years. Living alone was a risk factor for low QoL, but was not significantly associated with frailty prognosis. Conclusions: Prefrail and frail individuals were vulnerable to changes in socioeconomic support and more sensitive to it compared with robust individuals. Preferential policies regarding financial support, social support, and medical insurance should be developed for individuals with frailty.

18.
Mikrochim Acta ; 191(7): 407, 2024 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-38898338

RESUMO

A smartphone-based electrochemical aptasensing platform was developed for the point-of-care testing (POCT) of carcinoembryonic antigen (CEA) based on the ferrocene (Fc) and PdPt@PCN-224 dual-signal labeled strategy. The prepared PdPt@PCN-224 nanocomposite showed a strong catalytic property for the reduction of H2O2. Phosphate group-labeled aptamer could capture PdPt@PCN-224 by Zr-O-P bonds to form PdPt@PCN-224-P-Apt. Therefore, a dual signal labeled probe was formed by the hybridization between Fc-DNA and PdPt@PCN-224-P-Apt. The presence of CEA forced PdPt@PCN-224-P-Apt to leave the electrode surface due to the specific affinity, leading to the decrease of the reduction current of H2O2. At the same time, the Fc-DNA strand changed to hairpin structure, which made Fc closer to the electrode and resulted in the increase of the oxidation current of Fc. Thus, CEA can be accurately determined through both signals: the decrease of H2O2 reduction current and the increase of Fc oxidation current, which could avoid the false positive signal. Under the optimal conditions, the prepared aptasensor exhibited a wide linear range from 1 pg·mL-1 to 100 ng·mL-1 and low detection limits of 0.98 pg·mL-1 and 0.27 pg·mL-1 with Fc and PdPt@PCN-224 as signal labels, respectively. The aptasensor developed in this study has successfully demonstrated its capability to detect CEA in real human serum samples. These findings suggest that the proposed sensing platform will hold great potential for clinical tumor diagnosis and monitoring.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Antígeno Carcinoembrionário , Técnicas Eletroquímicas , Compostos Ferrosos , Peróxido de Hidrogênio , Limite de Detecção , Paládio , Testes Imediatos , Smartphone , Antígeno Carcinoembrionário/sangue , Antígeno Carcinoembrionário/análise , Aptâmeros de Nucleotídeos/química , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Humanos , Técnicas Biossensoriais/métodos , Peróxido de Hidrogênio/química , Paládio/química , Compostos Ferrosos/química , Metalocenos/química , Platina/química
19.
Materials (Basel) ; 17(10)2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38793426

RESUMO

In this study, we investigated the micromechanical deformation and damage behavior of commercially extruded and additively manufactured 316L stainless steels (AMed SS316L) by combining experimental examinations and crystal plasticity modeling. The AMed alloy was fabricated using the laser powder bed fusion (LPBF) technique with an orthogonal scanning strategy to control the directionality of the as-fabricated material. Optical microscopy and electron backscatter diffraction measurements revealed distinct grain morphologies and crystallographic textures in the two alloys. Uniaxial tensile test results suggested that the LPBFed alloy exhibited an increased yield strength, reduced elongation, and comparable ultimate tensile strength in comparison to those of the extruded alloy. A microstructure-based crystal plasticity model was developed to simulate the micromechanical deformation behavior of the alloys using representative volume elements based on realistic microstructures. A ductile fracture criterion based on the microscopically dissipated plastic energy on a slip system was adopted to predict the microscopic damage accumulation of the alloys during plastic deformation. The developed model could accurately predict the stress-strain behavior and evolution of the crystallographic textures in both the alloys. We reveal that the increased yield strength in the LPBFed alloy, compared to that in the extruded alloy, is attributed to the higher as-manufactured dislocation density and the cellular subgrain structure, resulting in a reduced elongation. The presence of annealing twins and favorable texture in the extruded alloy contributed to its excellent elongation, along with a higher hardening rate owing to twin-dislocation interactions during plastic deformation. Moreover, the grain morphology and defect state (e.g., dislocations and twins) in the initial state can significantly affect strain localization and damage accumulation in alloys.

20.
Anal Chem ; 96(21): 8365-8372, 2024 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-38717986

RESUMO

Simultaneous sensitive and precise determination of multibiomarkers is of great significance for improving detection efficiency, reducing diagnosis and treatment expenses, and elevating survival rates. However, the development of simple and portable biosensors for simultaneous determination of multiplexed targets in biological fluids still faces challenges. Herein, a unique and versatile immobilization-free dual-target electrochemical biosensing platform, which combines distinguishable magnetic signal reporters with buoyancy-magnetism separation, was designed and constructed for simultaneous detection of carcinoembryonic (CEA) and α-fetoprotein (AFP) in intricate biological fluids. To construct such distinguishable magnetic signal reporters with signal transduction, amplification, and output, secondary antibodies of CEA and AFP were respectively functionalized on methylene blue (MB) and 6-(ferrocenyl)hexanethiol (FeC) modified Fe3O4@Au magnetic nanocomposites. Meanwhile, a multifunctional flotation probe with dual target recognition, capture, and isolation capability was prepared by conjugating primary antibodies (Ab1-CEA, Ab1-AFP) to hollow buoyant microspheres. The target antigens of CEA and AFP can trigger a flotation-mediated sandwich-type immunoreaction and capture a certain amount of the distinguishable magnetic signal reporter, which enables the conversion of the target CEA and AFP quantities to the signal of the potential-resolved MB and FeC. Thus, the MB and FeC currents of magnetically adsorbed distinguishable magnetic reporters can be used to determine the CEA and AFP targets simultaneously and precisely. Accordingly, the proposed strategy exhibited a delightful linear response for CEA and AFP in the range of 100 fg·mL-1-100 ng·mL-1 with detection limits of 33.34 and 17.02 fg·mL-1 (S/N = 3), respectively. Meanwhile, no significant nonspecific adsorption and cross-talk were observed. The biosensing platform has shown satisfactory performance in the determination of real clinical samples. More importantly, the proposed approach can be conveniently extended to universal detection just by simply substituting biorecognition events. Thus, this work opens up a new promising perspective for dual and even multiple targets and offers promising potential applications in clinical diagnosis.


Assuntos
Técnicas Biossensoriais , Antígeno Carcinoembrionário , Técnicas Eletroquímicas , alfa-Fetoproteínas , alfa-Fetoproteínas/análise , alfa-Fetoproteínas/imunologia , Antígeno Carcinoembrionário/análise , Antígeno Carcinoembrionário/imunologia , Técnicas Biossensoriais/métodos , Humanos , Imunoensaio/métodos , Ouro/química , Limite de Detecção
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