Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 19 de 19
Filter
Add more filters










Publication year range
1.
Langmuir ; 40(23): 12301-12312, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38809168

ABSTRACT

The design of Janus materials offers an effective means of regulating both their physical and chemical properties, leading to their application in various fields. However, the underlying mechanism governing the modulation of the thermal transport characteristics through the construction of Janus materials remains unclear. In this work, we introduce VI-group elements into the MoSi2N4 structure, yielding two-dimensional Janus MoXSiN2 (X = S, Se, and Te) and systematically investigate their thermal transport properties based on first-principles calculation methods. Our findings reveal that the lattice thermal conductivities (κl) of MoSSiN2, MoSeSiN2, and MoTeSiN2 are 47.2, 24.3, and 40.6 W/mK at 300 K, respectively, significantly lower than that of MoSi2N4 (224 W/mK). Such low κl values mainly come from the introduction of X atoms, which enhances phonon scattering and reduces phonon vibration frequencies. In addition, MoTeSiN2 exhibits a higher κl compared to MoSeSiN2, contrary to the trend observed in most materials containing VI-group elements, where κl decreases gradually from S to Te. This anomalous behavior can be attributed to the competitive result between its lower phonon vibrational frequency and weaker phonon anharmonicity of MoTeSiN2. This work elucidates the inherent mechanism governing the modulation of thermal transport properties in Janus materials, thereby enhancing the potential application of Janus MoXSiN2 in engineering thermal management.

2.
Langmuir ; 40(18): 9775-9784, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38664863

ABSTRACT

We obtained a new material called monolayer 1T-Ag6S2 by replacing metal atoms in 1T phase transition-metal dichalcogenide sulfides (TMDs) with octahedral Ag6 clusters. Subsequently, the thermoelectric transport properties of monolayer 1T-Ag6S2 were systematically investigated using first-principles calculations and the generalized gradient approximation (GGA-PBE) exchange correlation functional. The findings demonstrate that monolayer 1T-Ag6S2 displays characteristics of a wide-bandgap semiconductor, with a bandgap of 2.48 eV. Notably, the incorporation of Ag6 clusters disrupts the structural symmetry, effectively enhancing the electronic structure and phonon properties of the material. Due to the flat valence band near the Fermi level, the extended relaxation time of the hole results in a greater effective mass compared to the electron, leading to a significant increase in the Seebeck coefficient. Under optimal doping conditions, the power factor of monolayer 1T-Ag6S2 can achieve 14.9 mW/mK2 at 500 K. The intricate crystal structure induces phonon path bending, reduces the overall frequency of phonon vibrations (<10 THz), and causes hybridization of low-frequency optical and acoustic branches, resulting in remarkably low lattice thermal conductivity (0.20 and 0.17 W/mK along the x and y axes at 500 K, respectively). The monolayer 1T-Ag6S2 demonstrates a remarkably high figure of merit ZT of 3.14 (3.15) on the x (y) axis at 500 K, significantly higher than those of conventional TMD materials. Such excellent thermoelectric properties suggest that monolayer 1T-Ag6S2 is a promising thermoelectric (TE) material. Our work reveals the deep mechanism of cluster substitution to optimize the thermoelectric properties of materials and provides a useful reference for subsequent research.

3.
Langmuir ; 40(15): 7992-8001, 2024 Apr 16.
Article in English | MEDLINE | ID: mdl-38561994

ABSTRACT

Two-dimensional (2D) materials with a pentagonal structure have many unique physical properties and great potential for applications in electrical, thermal, and optical fields. In this paper, the intrinsic thermal transport properties of 2D pentagonal CX2 (X = N, P, As, and Sb) are comparatively investigated. The results show that penta-CN2 has a high thermal conductivity (302.7 W/mK), while penta-CP2, penta-CAs2, and penta-CSb2 have relatively low thermal conductivities of 60.0, 36.9, and 11.8 W/mK, respectively. The main reason for the high thermal conductivity of penta-CN2 is that the small atomic mass of the N atom is comparable to that of the C atom, resulting in a preferable pentagonal structure with stronger bonds and thus a higher phonon group velocity. The reduction in the thermal conductivity of the other three materials is mainly due to the gradually increased atomic mass from P to Sb, which reduces the phonon group velocity. In addition, the large atomic mass difference does not result in a huge enhancement of the anharmonicity or weakening of the phonon relaxation time. The present work is expected to deepen the understanding of the thermal transport of main group V 2D pentagonal carbons and pave the way for their future applications, also, providing ideas for finding potential thermal management materials.

4.
Cell Mol Biol Lett ; 29(1): 39, 2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38504159

ABSTRACT

BACKGROUND: IGF2BP3 functions as an RNA-binding protein (RBP) and plays a role in the posttranscriptional control of mRNA localization, stability, and translation. Its dysregulation is frequently associated with tumorigenesis across various cancer types. Nonetheless, our understanding of how the expression of the IGF2BP3 gene is regulated remains limited. The specific functions and underlying mechanisms of IGF2BP3, as well as the potential benefits of targeting it for therapeutic purposes in bladder cancer, are not yet well comprehended. METHODS: The mRNA and protein expression were examined by RT-qPCR and western blotting, respectively. The methylation level of CpG sites was detected by Bisulfite sequencing PCR (BSP). The regulation of IGF2BP3 expression by miR-320a-3p was analyzed by luciferase reporter assay. The functional role of IGF2BP3 was determined through proliferation, colony formation, wound healing, invasion assays, and xenograft mouse model. The regulation of HMGB1 by IGF2BP3 was investigated by RNA immunoprecipitation (RIP) and mRNA stability assays. RESULTS: We observed a significant elevation in IGF2BP3 levels within bladder cancer samples, correlating with more advanced stages and grades, as well as an unfavorable prognosis. Subsequent investigations revealed that the upregulation of IGF2BP3 expression is triggered by copy number gain/amplification and promoter hypomethylation in various tumor types, including bladder cancer. Furthermore, miR-320a-3p was identified as another negative regulator in bladder cancer. Functionally, the upregulation of IGF2BP3 expression exacerbated bladder cancer progression, including the proliferation, migration, and invasion of bladder cancer. Conversely, IGF2BP3 silencing produced the opposite effects. Moreover, IGF2BP3 expression positively correlated with inflammation and immune infiltration in bladder cancer. Mechanistically, IGF2BP3 enhanced mRNA stability and promoted the expression of HMGB1 by binding to its mRNA, which is a factor that promotes inflammation and orchestrates tumorigenesis in many cancers. Importantly, pharmacological inhibition of HMGB1 with glycyrrhizin, a specific HMGB1 inhibitor, effectively reversed the cancer-promoting effects of IGF2BP3 overexpression in bladder cancer. Furthermore, the relationship between HMGB1 mRNA and IGF2PB3 is also observed in mammalian embryonic development, with the expression of both genes gradually decreasing as embryonic development progresses. CONCLUSIONS: Our present study sheds light on the genetic and epigenetic mechanisms governing IGF2BP3 expression, underscoring the critical involvement of the IGF2BP3-HMGB1 axis in driving bladder cancer progression. Additionally, it advocates for the investigation of inhibiting IGF2BP3-HMGB1 as a viable therapeutic approach for treating bladder cancer.


Subject(s)
HMGB1 Protein , MicroRNAs , Urinary Bladder Neoplasms , Humans , Animals , Mice , MicroRNAs/genetics , HMGB1 Protein/genetics , HMGB1 Protein/metabolism , Cell Line, Tumor , Carcinogenesis/genetics , DNA Methylation , Urinary Bladder Neoplasms/genetics , Urinary Bladder Neoplasms/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA Stability , Inflammation/genetics , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic , Mammals/genetics
5.
PLoS One ; 19(2): e0289129, 2024.
Article in English | MEDLINE | ID: mdl-38330003

ABSTRACT

To further enhance the residual current detection capability of low-voltage distribution networks, an improved adaptive residual current detection method that combines variational modal decomposition (VMD) and BP neural network (BPNN) is proposed. Firstly, the method employs the envelope entropy as the adaptability function, optimizes the [k, ɑ] combination value of the VMD decomposition using the bacterial foraging-particle swarm algorithm (BFO-PSO), and utilizes the interrelation number R as the classification index with the Least Mean Square Algorithm (LMS) to classify, filter, and extract the effective signal from the decomposed signal. Then, the extracted signals are detected by BPNN, and the training data are utilized to predict the residual current signals. Simulation and experimental data demonstrate that the proposed algorithm exhibits strong robustness and high detection accuracy. With an ambient noise of 10dB, the signal-to-noise ratio is 16.3108dB, the RMSE is 0.4359, and the goodness-of-fit is 0.9627 after processing by the algorithm presented in this paper, which are superior to the Variational Modal Decomposition-Long Short-Term Memory (VMD-LSTM) and Normalized-Least Mean Square (N-LMS) detection methods. The results were also statistically analyzed in conjunction with the Kolmogorov-Smirnov test, which demonstrated significance at the experimental data level, indicating the high accuracy of the algorithms presented in this paper and providing a certain reference for new residual current protection devices for biological body electrocution.


Subject(s)
Algorithms , Neural Networks, Computer , Computer Simulation , Entropy , Memory, Long-Term
6.
Eur J Dermatol ; 33(4): 350-359, 2023 Aug 01.
Article in English | MEDLINE | ID: mdl-37823486

ABSTRACT

Aquaporins (AQPs) are a family of transmembrane channel proteins that can rapidly transport water molecules. The main subtype expressed in the epidermis and dermis is AQP3. Studies have confirmed that AQPs exert certain physiological functions in the skin, such as the maintenance of normal shape, the regulation of body temperature, moisturization and hydration, anti-aging, damage repair and antigen presentation. The abnormal expression of AQPs in skin cells can lead to a variety of skin diseases. This review summarizes the relevance of AQPs in dermatophysiological and pathophysiological processes, highlighting their potential as new drug targets for the treatment of skin diseases.


Subject(s)
Aquaporins , Skin Diseases , Humans , Aquaporin 3 , Aquaporins/metabolism , Skin/metabolism , Epidermis/metabolism , Skin Diseases/metabolism
7.
Cell Death Discov ; 9(1): 191, 2023 Jun 26.
Article in English | MEDLINE | ID: mdl-37365152

ABSTRACT

Esophageal cancer (ESCA) is the seventh most frequent and deadly neoplasm. Due to the lack of early diagnosis and high invasion/metastasis, the prognosis of ESCA remains very poor. Herein, we identify skin-related signatures as the most deficient signatures in invasive ESCA, which are regulated by the transcription factor ZNF750. Of note, we find that TRIM29 level strongly correlated with the expression of many genes in the skin-related signatures, including ZNF750. TRIM29 is significantly down-regulated due to hypermethylation of its promoter in both ESCA and precancerous lesions compared to normal tissues. Low TRIM29 expression and high methylation levels of its promoter are associated with malignant progression and poor clinical outcomes in ESCA patients. Functionally, TRIM29 overexpression markedly hinders proliferation, migration, invasion, and epithelial-mesenchymal transition of esophageal cancer cells, whereas opposing results are observed when TRIM29 is silenced in vitro. In addition, TRIM29 inhibits metastasis in vivo. Mechanistically, TRIM29 downregulation suppresses the expression of the tumor suppressor ZNF750 by activating the STAT3 signaling pathway. Overall, our study demonstrates that TRIM29 expression and its promoter methylation status could be potential early diagnostic and prognostic markers. It highlights the role of the TRIM29-ZNF750 signaling axis in modulating tumorigenesis and metastasis of esophageal cancer.

8.
Protein Pept Lett ; 30(1): 2-12, 2023.
Article in English | MEDLINE | ID: mdl-36424802

ABSTRACT

Cold-induced RNA-binding protein (CIRP) and RNA-binding motif protein 3 (RBM3) have recently been reported to be involved in cold stress in mammals. These proteins are expressed at low levels in various normal cells, tissues, and organs but can be upregulated upon stimulation by multiple stressors. Studies have shown that CIRP and RBM3 are multifunctional RNA molecular chaperones with different biological functions in various physiological and pathophysiological processes, such as reproductive development, the inflammatory response, the immune response, nerve injury regulation, and tumorigenesis. This paper reviews recent studies on the structure, localization and correlation of CIRP and RBM3 with reproductive development and reproductive system diseases.


Subject(s)
RNA-Binding Proteins , RNA , Animals , RNA-Binding Proteins/chemistry , Molecular Chaperones/metabolism , Genitalia/metabolism , RNA-Binding Motifs , Mammals/genetics , Mammals/metabolism
9.
Sci Adv ; 8(27): eabo2068, 2022 Jul 08.
Article in English | MEDLINE | ID: mdl-35857469

ABSTRACT

Materials with excellent high-temperature strength are now sought for applications in hypersonics, fusion reactors, and aerospace technologies. Conventional alloys and eutectic multiprincipal-element alloys (MPEAs) exhibit insufficient strengths at high temperatures due to low melting points and microstructural instabilities. Here, we report a strategy to achieve exceptional high-temperature microstructural stability and strength by introducing eutectic carbide in a refractory MPEA. The synergistic strengthening effects from the multiprincipal-element mixing and strong dislocation blocking at the interwoven metal-carbide interface make the eutectic MPEA not only have outstanding high-temperature strength (>2 GPa at 1473 K) but also alleviate the room-temperature brittleness through microcrack tip blunting by layered metallic phase. This strategy offers a paradigm for the design of the next-generation high-temperature materials to bypass the low-melting point limitation of eutectic alloys and diffusion-dominated softening in conventional superalloys.

10.
Interdiscip Sci ; 14(2): 311-330, 2022 Jun.
Article in English | MEDLINE | ID: mdl-34731411

ABSTRACT

Accurate prediction of drug-target interactions (DTIs), which is often used in the fields of drug discovery and drug repositioning, is regarded a key challenge in the study of drug science. In this paper, a new method called DeepStack-DTIs is proposed to predict DTIs. First, for the target protein, pseudo-position specific score matrix, pseudo amino acid composition and SPIDER3 are used to extract the different feature information of the target protein. Meanwhile, the path-based fingerprint features of each drug are extracted. Then, the synthetic minority oversampling technique (SMOTE) and light gradient boosting machine (LightGBM) are used for data balancing and feature selection, respectively. Finally, the processed features are input to the deep-stacked ensemble classifier composed of gated recurrent unit (GRU), deep neural network (DNN), support vector machine (SVM), eXtreme gradient boosting (XGBoost) and logistic regression (LR) to predict DTIs. Under the five-fold cross-validation and compared with existing methods, the proposed method achieves higher prediction accuracy on the gold standard dataset. To evaluate the predictive power of DeepStack-DTIs, we validate the method on another dataset and predict the drug-target interaction network. The results indicate that DeepStack-DTIs has excellent predictive ability than the other methods, and provides novel insights for the prediction of DTIs. A novel method DeepStack-DTIs for drug-target interactions prediction. PsePSSM, PseAAC, SPIDER3 and FP2 are fused to convert protein sequence and drug molecule information into digital information, respectively. The SMOTE algorithm is used to balance the dataset and LightGBM feature selection algorithm is employed to remove redundant and irrelevant features to select the optimal feature subset. This optimal feature subset is inputted into the deep-stacked ensemble classifier to predict drug-target interactions. The experimental results show DeepStack-DTIs method can significantly improve the prediction accuracy of drug-target interactions.


Subject(s)
Algorithms , Proteins , Amino Acid Sequence , Neural Networks, Computer , Proteins/chemistry , Support Vector Machine
11.
Front Cell Neurosci ; 15: 704344, 2021.
Article in English | MEDLINE | ID: mdl-34335194

ABSTRACT

Background: Chromosome 1p/19q codeletion is one of the most important genetic alterations for low grade gliomas (LGGs), and patients with 1p/19q codeletion have significantly prolonged survival compared to those without the codeletion. And the tumor immune microenvironment also plays a vital role in the tumor progression and prognosis. However, the effect of 1p/19q codeletion on the tumor immune microenvironment in LGGs is unclear. Methods: Immune cell infiltration of 281 LGGs from The Cancer Genome Atlas (TCGA) and 543 LGGs from the Chinese Glioma Genome Atlas (CGGA) were analyzed for immune cell infiltration through three bioinformatics tools: ESTIMATE algorithm, TIMER, and xCell. The infiltrating level of immune cells and expression of immune checkpoint genes were compared between different groups classified by 1p/19q codeletion and IDH (isocitrate dehydrogenase) mutation status. The differential biological processes and signaling pathways were evaluated through Gene Set Enrichment Analysis (GSEA). Correlations were analyzed using Spearman correlation. Results: 1p/19q codeletion was associated with immune-related biological processes in LGGs. The infiltrating level of multiple kinds of immune cells and expression of immune checkpoint genes were significantly lower in 1p/19q codeletion LGGs compared to 1p/19q non-codeletion cohorts. There are 127 immune-related genes on chromosome 1p or 19q, such as TGFB1, JAK1, and CSF1. The mRNA expression of these genes was positively correlated with their DNA copy number. These genes are distributed in multiple immune categories, such as chemokines/cytokines, TGF-ß family members, and TNF family members, regulating immune cell infiltration and expression of the immune checkpoint genes in tumors. Conclusion: Our results indicated that 1p/19q codeletion status is closely associated with the immunosuppressive microenvironment in LGGs. LGGs with 1p/19q codeletion display less immune cell infiltration and lower expression of immune checkpoint genes than 1p/19q non-codeletion cases. Mechanistically, this may be, at least in part, due to the deletion of copy number of immune-related genes in LGGs with 1p/19q codeletion. Our findings may be relevant to investigate immune evasion in LGGs and contribute to the design of immunotherapeutic strategies for patients with LGGs.

12.
Front Bioeng Biotechnol ; 9: 690186, 2021.
Article in English | MEDLINE | ID: mdl-34307322

ABSTRACT

NLRC5 is an important regulator in antigen presentation and inflammation, and its dysregulation promotes tumor progression. In melanoma, the impact of NLRC5 expression on molecular phenotype, clinical characteristics, and tumor features is largely unknown. In the present study, public datasets from the Cancer Cell Line Encyclopedia (CCLE), Gene Expression Omnibus (GEO), The Cancer Genome Atlas (TCGA), and cBioPortal were used to address these issues. We identify that NLRC5 is expressed in both immune cells and melanoma cells in melanoma samples and its expression is regulated by SPI1 and DNA methylation. NLRC5 expression is closely associated with Breslow thickness, Clark level, recurrence, pathologic T stage, and ulceration status in melanoma. Truncating/splice mutations rather than missense mutations in NLRC5 could compromise the expression of downstream genes. Low expression of NLRC5 is associated with poor prognosis, low activity of immune-related signatures, low infiltrating level of immune cells, and low cytotoxic score in melanoma. Additionally, NLRC5 expression correlates with immunotherapy efficacy in melanoma. In summary, these findings suggest that NLRC5 acts as a tumor suppressor in melanoma via modulating the tumor immune microenvironment. Targeting the NLRC5 related pathway might improve efficacy of immunotherapy for melanoma patients.

13.
Cancer Cell Int ; 20: 479, 2020.
Article in English | MEDLINE | ID: mdl-33024417

ABSTRACT

[This corrects the article DOI: 10.1186/s12935-020-01298-5.].

14.
Cancer Cell Int ; 20: 210, 2020.
Article in English | MEDLINE | ID: mdl-32514254

ABSTRACT

BACKGROUND: Hydroxysteroid 17-Beta Dehydrogenase 6 (HSD17B6), a key protein involved in synthetizing dihydrotestosterone, is abundant in the liver. Previous studies have suggested a role for dihydrotestosterone in modulating progress of various malignancies, and HSD17B6 dysfunction was associated with lung cancer and prostate cancer. However, little is known about the detailed role of HSD17B6 in hepatocellular carcinoma (HCC). METHODS: Clinical implication and survival data related to HSD17B6 expression in patients with HCC were obtained through TCGA, ICGC, ONCOMINE, GEO and HPA databases. Survival analysis plots were drawn with Kaplan-Meier Plotter. The ChIP-seq data were obtained from Cistrome DB. Protein-Protein Interaction and gene functional enrichment analyses were performed in STRING database. The correlations between HSD17B6 and tumor immune infiltrates was investigated via TIMER and xCell. The proliferation, migration and invasion of liver cancer cells transfected with HSD17B6 were evaluated by the CCK8 assay, wound healing test and transwell assay respectively. Expression of HSD17B6, TGFB1 and PD-L1 were assessed by quantitative RT-PCR. RESULTS: HSD17B6 expression was lower in HCC compared to normal liver and correlated with tumor stage and grade. Lower expression of HSD17B6 was associated with worse OS, PFS, RFS and DSS in HCC patients. HNF4A bound to enhancer and promoter regions of HSD17B6 gene, activating its transcription, and DNA methylation of HSD17B6 promoter negatively controlled the expression. HSD17B6 and its interaction partners were involved in androgen metabolism and biosynthesis in liver. HSD17B6 inhibited tumor cell proliferation, migration and invasion in liver cancer cells and low expression of HSD17B6 correlated with high immune cells infiltration, relative reduction of immune responses and multiple immune checkpoint genes expression in HCC, probably by regulating the expression of TGFB1. CONCLUSIONS: This study indicate that HSD17B6 could be a new biomarker for the prognosis of HCC and an important negative regulator of immune responses in HCC.

15.
Tissue Cell ; 59: 10-17, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31383284

ABSTRACT

Domestic Pigeon (Columba livia) is one of few domesticated birds with an important economic value. In this study, a comprehensive investigation on the morphology and cytochemical patterns of peripheral blood cells in domestic pigeons were conducted by using wright's and various cytochemical staining techniques including periodic acid-Schiff(PAS), sudan black B(SBB), peroxidase(POX), alkaline phosphatase(ALP), acid phosphatase(ACP), chloroacetic acid AS-D naphthol esterase(AS-D) and α-naphthol acetate esterase(α-NAE) staining. Besides erythrocytes and thrombocytes, five types of leukocytes were identified: heterophils, eosinophils, basophils, lymphocytes and monocytes. Lymphocytes were the most abundant leukocytes, followed by heterophils, eosinophils, monocytes; basophils were the fewest. Erythrocytes and thrombocytes were positive for PAS, and negative for all the other cytochemical staining. Heterophils and eosinophils exhibited positive to all cytochemical staining except for α-NAE. Basophils exhibited strongly positive for POX and AS-D, positive for PAS and ALP, while negative for SBB, ACP and α-NAE staining. Monocytes exhibited positive for PAS and α-NAE, and weakly positive for ACP, while negative for SBB, POX, ALP and AS-D staining. Lymphocytes showed positive for PAS and ACP, weakly positive for AS-D, while negative for SBB, POX, ALP and α-NAE staining. Our results add up knowledge about the domestic pigeon blood cells.


Subject(s)
Blood Cells/cytology , Blood Cells/metabolism , Columbidae/metabolism , Animals , Staining and Labeling
16.
Tissue Cell ; 55: 71-76, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30503062

ABSTRACT

The Chinese alligator (Alligator sinensis) is an endemic rare crocodilian species in China. In this study, we investigated the cytochemical patterns of peripheral blood cells in Chinese alligators for the first time by a range of cytochemical staining techniques including periodic acid-Schiff(PAS), sudan black B(SBB), peroxidase(POX), alkaline phosphatase(AKP), acid phosphatase(ACP), chloroacetic acid AS-D naphthol esterase(AS-D) and α-naphthol acetate esterase(α-NAE) staining. Erythrocytes were positive for PAS, and negative for all the other staining; heterophils were strongly positive for SBB, POX, ACP, AKP, AS-D and α-NAE, while weakly positive for PAS staining; eosinophils were strongly positive for PAS, POX, AKP, ACP and AS-D, and weakly positive for SBB and α-NAE staining; basophils were strongly positive for PAS, positive for POX, ACP, AKP and α-NAE, and weakly positive for AS-D, while negative for SBB staining; monocytes were weakly positive for PAS, ACP, AKP and α-NAE, while negative for SBB, POX and AS-D staining; lymphocytes were weakly positive for PAS and α-NAE, negative for all the other staining; thrombocytes were weakly positive for PAS, and negative for all the other staining. Our results add up knowledge about Chinese alligator blood cells.


Subject(s)
Blood Platelets/cytology , Erythrocytes/cytology , Leukocytes/cytology , Lymphocytes/cytology , Alligators and Crocodiles , Animals , Monocytes/cytology , Neutrophils/cytology
17.
Nanoscale Res Lett ; 10(1): 999, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26168866

ABSTRACT

We report the capacitance-voltage (C-V) measurements on thin-film transistors (TFTs) using solution-processed semiconducting carbon nanotube networks with different densities and channel lengths. From the measured C-V characteristics, gate capacitance and field-effect mobility (up to ~50 cm(2) V(-1) s(-1)) of the TFTs were evaluated with better precision compared with the results obtained from calculated gate capacitance. The C-V characteristics measured under different frequencies further enabled the extraction and analysis of the interface trap density at the nanotube-dielectric layer interface, which was found to increase significantly as the network density increases. The results presented here indicate that C-V measurement is a powerful tool to assess the electrical performance and to investigate the carrier transport mechanism of TFTs based on carbon nanotubes.

18.
J Colloid Interface Sci ; 404: 223-9, 2013 Aug 15.
Article in English | MEDLINE | ID: mdl-23711661

ABSTRACT

Gold nanoparticles (AuNPs) have significant potential as biosensors and drug delivery vehicles, as well as imaging and thermotherapy agents. Thiol-containing polyethylene glycol (PEG), hereafter denoted as thiol-PEG, is widely used as a macromolecular ligand for modifying AuNPs and stabilizing them under various environments. In this work, a series of thiol-PEG-modified AuNPs (PEGylated AuNPs) with different PEG molecular weights (Mw) were synthesized. The saturated capping density, charge-screening ability, and stability of the PEGylated AuNPs were then examined. The results showed that high-Mw PEG stabilized the AuNPs and screened the surface charge better than low-Mw PEG, but the latter showed higher saturated capping density. More importantly, PEG exhibited the maximum coagulation concentration (MCC) and critical stabilization concentration (CSC) in the stabilizing process of the AuNPs. Thiol-PEG acted as an AuNP stabilizer only when its concentration was higher than the CSC. Otherwise, thiol-PEG accelerated AuNPs aggregation, which reached the peak level at the MCC. These results were significant in recognizing the influence of thiol-PEG on the stability of AuNPs.


Subject(s)
Gold/chemistry , Metal Nanoparticles/chemistry , Polyethylene Glycols/chemistry , Sulfhydryl Compounds/chemistry
19.
Langmuir ; 27(18): 11457-65, 2011 Sep 20.
Article in English | MEDLINE | ID: mdl-21861532

ABSTRACT

A rapid, effective method for the screening of adsorbent ligands based on the unique optical properties of gold colloid has been developed. Different interactions between adsorbate and ligands induce different states of aggregation of the gold colloid, and the associated distinct color changes of the colloid have been utilized to estimate the affinity of the ligands toward the adsorbate. In this work, phosphorylated peptide CGGFGGpSG was appended to a gold colloid to obtain the adsorbate-modified gold colloid (CG8-AuNPs). Candidate ligands Dpa-Zn(2+), DMAPAA, and AAn were copolymerized with acrylamide to form linear polymers and cross-linked CG8-AuNPs to induce aggregation. Screening of the candidate ligands revealed that Dpa-Zn(2+) showed the highest affinity among those tested, inducing a color change of the gold colloid at a concentration of 10 µM, which is much lower than those of ligands DMAPAA (40 µM) and AAn (almost no color change could be observed). Subsequent statistical adsorption experiments confirmed these screening results, with the adsorbent A-AAm-Dpa-Zn(2+) showing the highest adsorption capacity (426 mg/g) for CG-8, almost twice that of adsorbent A-AAm-DMAPAA. This reported method has low sample consumption, and the screening may be simply monitored by the naked eye.


Subject(s)
Gold/chemistry , Adsorption , Amino Acid Sequence , Colloids , Immobilized Proteins/chemistry , Ligands , Oligopeptides/chemistry , Reproducibility of Results
SELECTION OF CITATIONS
SEARCH DETAIL
...