RESUMO
Microplastics can enter the human body through the food chain and can cause cardiovascular or cerebrovascular diseases; thus, it is essential to detect microplastics sensitively and accurately. Traditional methods have some drawbacks, such as a low sensitivity and complicated experimental procedures, so it is difficult to detect microplastics less than 1 µm. While surface enhanced Raman scattering technology can compensate for these shortcomings, there are fewer reports on the quantitative detection of microplastics using SERS technology. In this study, SERS and an internal standard method were utilized to detect microplastics qualitatively and quantitatively. The electric field enhancement effect of common gold, silver, and copper substrates were simulated by the finite element method, and the influence rule of structural parameters on the enhancement factor was obtained to optimize structural parameters. Subsequently, a gold nanopyramid array substrate was prepared using the colloidal sphere template method. Finally, the prepared substrate was applied to detect polystyrene microplastics with a diameter of 500 nm, and the detection of limit is 1.8 × 10-4 mg mL-1 in the quantitative range of 2-2 × 10-4 mg mL-1, and the correlation coefficient of the linear regression equation is 0.9918. The experimental results showed that this proposal has a lower detection limit and a wider quantitative range and expands ideas for the qualitative and quantitative detection of microplastics in seawater.
RESUMO
In antifouling applications for the marine industry, low surface energy coatings entail turbulent water flow to release marine biofouling, which presents a substantial challenge for antifouling in the static situation. The traditional solution is to add environmentally friendly antifouling agents, but it has the problem of exhaustion. Therefore, the low surface energy elastic antifouling coating without antifoulants has high research value. Herein, inspired by soft body and epidermal mucus of squid, the stable polyvinylpyrrolidone (PVP) hydrophilic segments were introduced to modify the polydimethylsiloxane-based polyurethane (PDMS-PU), realizing low surface energy elastomer coatings with hydrophilized defensive surface and reduced elastic modulus (<1.1 MPa). In an aqueous environment, the tailored surface exposed sufficient stable hydrophilic segments, exerting excellent antifouling performance, which improved the anti-adsorption effect on biological proteins, bacteria (antibacterial rate 95.24%) and algae (cover rate <3%). The coating exhibited excellent marine antifouling performance within 150 days and also gave a new impetus to developing an eco-friendly and sustainable solution for no-antifoulant marine antifouling applications.
Assuntos
Incrustação Biológica , Animais , Incrustação Biológica/prevenção & controle , Decapodiformes , Elastômeros , Interações Hidrofóbicas e Hidrofílicas , PoliuretanosRESUMO
Naikan is a contemplative self-observation practice that originated from Japanese Shin Buddhism and is utilized for rehabilitating prison inmates in many countries. Although some investigations have provided initial evidence for its efficiency in decreasing recidivism, there is still a need for further investigation of the effectiveness of Naikan on other outcomes through more controlled studies. The present study aimed to investigate the efficacy of Naikan therapy on male offenders' perceived social support and externalized blame. Ninety-two male offenders were randomly assigned to either the experimental group or to the waiting group. All participants were evaluated by the Multidimensional Scale of Perceived Social Support and the Externalization subscale of the Test of Self-Conscious Affect before and after Naikan therapy. The results suggested that participants who received Naikan therapy showed higher levels of perceived social support and lower levels of externalized blame after Naikan therapy than before.
Assuntos
Prisioneiros , Psicoterapia/métodos , Apoio Social , Adulto , China , Humanos , Masculino , Pessoa de Meia-Idade , Distribuição Aleatória , Adulto JovemRESUMO
A hybrid plasmonic waveguide consisting of a high-index dielectric core embedded inside a rectangular-shaped metallic trench is proposed and its guiding properties are investigated at the wavelength of 1550 nm. Numerical simulations based on the finite element method have demonstrated that the introduced dielectric core could greatly reduce the modal loss of the metal trench while maintaining strong confinement of light. The effects of dielectric core size, material of the cladding and the dielectric core on the modal properties have been systematically investigated. The proposed hybrid plasmonic structure can be realized employing fabrication techniques of the traditional metal trench waveguides and could be leveraged as important elements for highly-integrated photonic circuits.