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1.
Heliyon ; 6(2): e03368, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32099917

RESUMO

Severe stress and depression constitute serious challenges to people in both personal and public health. Numerous university students suffer from depression each year while only fractions of them receive proper and competent treatments. Following the trends of the era, social media has been prevalent among university students and become a new platform to disclose depression references. The purpose of this study is to examine the effects of various stressors and the "Big Five" personality traits towards the intention of disclosing depression. Addition to the disclosure intention, this study also explores if respondents have presented their depression via social media profiles. Over 200 WeChat users were surveyed on their experiences from psychological stress factors under four categories - academy, relationship and practical issues.

2.
Nanoscale ; 9(34): 12652-12663, 2017 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-28825749

RESUMO

The nanoassembly behavior of trivalent small molecule-DNA hybrids (SMDH3s) was investigated as a function of core geometry and supramolecular flexibility through a synergistic experimental-modeling study. While complementary SMDH3s possessing a highly flexible tetrahedral trivalent core primarily assemble into nanoscale caged dimers, the nanoassemblies of SMDH3 comonomers with rigid pyramidal and trigonal cores yield fewer caged dimers and more large-oligomer networks. Specifically, the rigid pyramidal SMDH3 comonomers tend to form smaller nanosized aggregates (dimers, tetramers, and hexamers) upon assembly, attributable to the small (<109°) branch-core-branch angle of the pyramidal core. In contrast, the more-rigid trigonal planar SMDH3 comonomers have a larger (∼120°) branch-core-branch angle, which spaces their DNA arms farther apart, facilitating the formation of larger nanoassemblies (≥nonamers). The population distributions of these nanoassemblies were successfully captured by coarse-grained molecular dynamics (CGMD) simulations over a broad range of DNA concentrations. CGMD simulations can also forecast the effect of incorporating Tn spacer units between the hydridizing DNA arms and the rigid organic cores to increase the overall flexibility of the SMDH3 comonomers. Such "decoupling" of the DNA arms from the organic core was found to result in preferential formation of nanoscale dimers up to an optimal spacer length, beyond which network formation takes over due to entropic factors. This excellent agreement between the simulation and experimental results confirms the versatility of the CGMD model as a useful and reliable tool for elucidating the nanoassembly of SMDH-based building blocks.


Assuntos
DNA/química , Simulação de Dinâmica Molecular , Nanoestruturas , Polímeros
3.
J Am Chem Soc ; 137(41): 13381-8, 2015 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-26398097

RESUMO

Two complementary small-molecule-DNA hybrid (SMDH) building blocks have been combined to form well-defined supramolecular cage dimers at DNA concentrations as high as 102 µM. This was made possible by combining a flexible small-molecule core and three DNA arms of moderate lengths (<20 base pairs). These results were successfully modeled by coarse-grained molecular dynamics simulations, which also revealed that the formation of ill-defined networks in the case of longer DNA arms can be significantly biased by the presence of deep kinetic traps. Notably, melting point studies revealed that cooperative melting behavior can be used as a means to distinguish the relative propensities for dimer versus network formation from complementary flexible three-DNA-arm SMDH (fSMDH3) components: sharp, enhanced melting transitions were observed for assemblies that result mostly in cage dimers, while no cooperative melting behavior was observed for assemblies that form ill-defined networks.


Assuntos
DNA/química , Dimerização , Simulação de Dinâmica Molecular , Eletroforese em Gel de Poliacrilamida Nativa
4.
J Am Chem Soc ; 137(15): 5113-22, 2015 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-25822073

RESUMO

DNA-based molecular electronics will require charges to be transported from one site within a 2D or 3D architecture to another. While this has been shown previously in linear, π-stacked DNA sequences, the dynamics and efficiency of charge transport across DNA three-way junction (3WJ) have yet to be determined. Here, we present an investigation of hole transport and trapping across a DNA-based three-way junction systems by a combination of femtosecond transient absorption spectroscopy and molecular dynamics simulations. Hole transport across the junction is proposed to be gated by conformational fluctuations in the ground state which bring the transiently populated hole carrier nucleobases into better aligned geometries on the nanosecond time scale, thus modulating the π-π electronic coupling along the base pair sequence.


Assuntos
DNA/química , Pareamento de Bases , Transporte de Elétrons , Cinética , Modelos Moleculares , Simulação de Dinâmica Molecular , Análise Espectral
5.
Knowl Based Syst ; 23(6): 626-633, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32288314

RESUMO

Nowadays, stock market is becoming a popular investment platform for both institutional and individual investors. The current financial information systems serve to provide latest information. However, they lack sophisticated analytical tools. This paper proposes a new architecture for financial information systems. The developed prototype is entitled as the Multi-level and Interactive Stock Market Investment System (MISMIS). It is specially designed for investors to build their financial models to forecast stock price and index. The performance of the financial models can be evaluated on a virtual trading platform. There are other features in MISMIS that are tailor-made to handle financial data; these include synchronized time frame, time series prediction techniques, preprocessing and transformation functions, multi-level modeling and interactive user interface. To illustrate the capability of MISMIS, we have evaluated strategies of trading the future options of Hang Seng Index (HSI). We find that historical HSI, Dow Jones Index, property price index, retailing sales figure, prime lending rate, and consumer price index in Hong Kong are essential factors affecting the performance of the trading of HSI's future option. Also there are some feedbacks from the in-depth interviews of six financial consultant upon how they perceived the prototype MISMIS.

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