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1.
J Am Chem Soc ; 146(9): 5908-5915, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38391353

RESUMO

Unconventional superconductivity in bulk materials under ambient pressure is extremely rare among the 3d transition metal compounds outside the layered cuprates and iron-based family. It is predominantly linked to highly anisotropic electronic properties and quasi-two-dimensional (2D) Fermi surfaces. To date, the only known example of a Co-based exotic superconductor is the hydrated layered cobaltate, NaxCoO2·yH2O, and its superconductivity is realized in the vicinity of a spin-1/2 Mott state. However, the nature of the superconductivity in these materials is still a subject of intense debate, and therefore, finding a new class of superconductors will help unravel the mysteries of their unconventional superconductivity. Here, we report the discovery of superconductivity at ∼6.3 K in our newly synthesized layered compound Na2CoSe2O, in which the edge-shared CoSe6 octahedra form [CoSe2] layers with a perfect triangular lattice of Co ions. It is the first 3d transition metal oxychalcogenide superconductor with distinct structural and chemical characteristics. Despite its relatively low TC, this material exhibits very high superconducting upper critical fields, µ0HC2(0), which far exceeds the Pauli paramagnetic limit by a factor of 3-4. First-principles calculations show that Na2CoSe2O is a rare example of a negative charge transfer superconductor. This cobalt oxychalcogenide with a geometrical frustration among Co spins shows great potential as a highly appealing candidate for the realization of unconventional and/or high-TC superconductivity beyond the well-established Cu- and Fe-based superconductor families and opens a new field in the physics and chemistry of low-dimensional superconductors.

2.
Nanomaterials (Basel) ; 12(19)2022 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-36234540

RESUMO

Caffeic acid is an antioxidant that has been widely been related to the health benefits of people in recent years. In this paper, the amino side chains of chitosan (CS) were modified with protoporphyrin IX by amide cross-linking, and then Zn ions were chelated. The properties of metalloporphyrin-preparing functionalized multi-walled carbon nanotubes (MWCNTs) and Zn ions chelated by protoporphyrin IX composites were used as sensitive-selective electrochemical biosensors for the determination of caffeic acid. The morphology and structure of nanocomposite Zn-PPIX-CS-MWCNTs were observed by X-ray spectroscopy mapping (EDX mapping), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FTIR). The electrochemical behaviors of Zn-PPIX-CS-MWCNT-modified glassy carbon (GC) electrodes were evaluated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The results show that the modified electrode had good electrocatalytic activity towards caffeic acid with a wide linear range of 0.0008-1.6 mM, an excellent sensitivity of 886.90 µAmM-1cm-1, and a detection limit of 0.022 µM. In addition, the caffeic acid sensor had excellent reproducibility, stability, and selectivity to various interfering substances. Therefore, the modified electrode prepared by this experiment can also be applied to electrochemical sensors of other substances.

3.
PLoS One ; 12(9): e0182438, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28926565

RESUMO

In the current precision medicine era, more and more samples get genotyped and sequenced. Both researchers and commercial companies expend significant time and resources to reduce the error rate. However, it has been reported that there is a sample mix-up rate of between 0.1% and 1%, not to mention the possibly higher mix-up rate during the down-stream genetic reporting processes. Even on the low end of this estimate, this translates to a significant number of mislabeled samples, especially over the projected one billion people that will be sequenced within the next decade. Here, we first describe a method to identify a small set of Single nucleotide polymorphisms (SNPs) that can uniquely identify a personal genome, which utilizes allele frequencies of five major continental populations reported in the 1000 genomes project and the ExAC Consortium. To make this panel more informative, we added four SNPs that are commonly used to predict ABO blood type, and another two SNPs that are capable of predicting sex. We then implement a web interface (http://qrcme.tech), nicknamed QRC (for QR code based Concordance check), which is capable of extracting the relevant ID SNPs from a raw genetic data, coding its genotype as a quick response (QR) code, and comparing QR codes to report the concordance of underlying genetic datasets. The resulting 80 fingerprinting SNPs represent a significant decrease in complexity and the number of markers used for genetic data labelling and tracking. Our method and web tool is easily accessible to both researchers and the general public who consider the accuracy of complex genetic data as a prerequisite towards precision medicine.


Assuntos
Polimorfismo de Nucleotídeo Único , Interface Usuário-Computador , Frequência do Gene , Genoma Humano , Genótipo , Humanos , Internet
4.
J Psychol ; 151(5): 453-463, 2017 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-28486077

RESUMO

This study examined loneliness and future orientation as predictors of suicidal risk, namely, depressive symptoms and suicide ideation, in a sample of 228 college students (54 males and 174 females). Results of regression analyses indicated that loneliness was a significant predictor of both indices of suicidal risk. The inclusion of future orientation was found to significantly augment the prediction model of both depressive symptoms and suicide ideation, even after accounting for loneliness. Noteworthy, beyond loneliness and future orientation, the Loneliness × Future Orientation interaction term was found to further augment both prediction models of suicidal risk. Consistent with the notion that future orientation is an important buffer of suicidal risk, among lonely students, those with high future orientation, compared to low future orientation, were found to report significantly lower levels of depressive symptoms and suicide ideation. Some implications of the present findings for studying both risk and protective factors associated with suicidal risk in young adults are discussed.


Assuntos
Solidão/psicologia , Ideação Suicida , Prevenção do Suicídio , Suicídio/psicologia , Adolescente , Adulto , Depressão/psicologia , Feminino , Humanos , Masculino , Análise de Regressão , Fatores de Risco , Estudantes/psicologia , Adulto Jovem
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