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The acoustic coding metasurfaces have attracted much attention recently for their unique and flexible control of wavefronts by arranging the binary elements in special sequences with antiphase responses. In this paper, we investigate the application of coding metasurfaces to manipulate the scattering features found under plane-wave illumination. Different coding strategies are considered to realize multibeam generation and construct meta-diffusers that can disperse incoming energy in various directions, leading to considerable suppression of acoustic waves traveling in specular directions. Both simulated and measured results demonstrate the powerful capability of wave manipulation by the coding metasurfaces, offering a new method for noise control in the future. [ABSTRACT FROM AUTHOR]

The purposes of this study were to examine the variables related to the special education students' stereotyped behavior in Taiwan, to understand types and functions of these students' stereotyped behavior, and to investigate the impact of such stereotypy on teaching in special educational classrooms. Questionnaires were sent to 308 classroom teachers and 3224 students with developmental disabilities were surveyed. The data were analyzed by descriptive and inferential statistics. Results indicated that the most common topographies of stereotypy were head shaking, body rocking, hand-biting, and hand-mouthing, and stereotypy often functioned to obtain sensory reinforcement and positive social reinforcement in both statistical analyses. Additionally, people with mental retardation emitted the highest rates of stereotypy in all students with developmental disabilities, and the peak of such aberrant behaviors appeared at the elementary school level. (Contains 3 tables.)

Acoustic metasurfaces have enabled unprecedented control over acoustic waves, offering opportunities in areas such as holographic rendering, sound absorption, and acoustic communication. Despite the steady progress made in this field, most acoustic metasurface designs are passive in that they only provide static functionalities. Here, a reconfigurable active acoustic metalens is implemented to showcase scanning of the focus along arbitrary trajectories in free space with the help of a previously developed active acoustic metasurface platform. Each unit cell of the metasurface contains a cavity, whose size can be tuned continuously by a dynamic control system to adjust the phase of the reflected wave. While this work focuses on beam focusing, it could hold great promise for a wide range of applications including acoustic levitation and tweezers. [ABSTRACT FROM AUTHOR]

Since nearly all studies concerning the approximate Crank–Nicolson perfectly matched layer (CN-PML) are limited to 2-D cases, a computationally efficient implementation that can be used to truncate 3-D finite-difference time-domain (FDTD) lattices is presented in this article. More precisely, it is based on the CN direct-splitting (DS) scheme and the bilinear transform (BT) method. This article can fully exploit the unconditional stability of the standard CN-FDTD method and can be free from the Courant–Friedrich–Lewy (CFL) limit; hence, it is especially suitable for situations where space discretization step is much smaller than 1/10th or 1/20th of the smallest wavelength of interest. Aiming at further reducing the requirement of the computer resources, this new implementation can be reformulated in more simple forms if proper auxiliary variables are introduced. It therefore shows a higher iteration speed than other published unconditionally stable PMLs as fewer numbers of arithmetic operations are involved. Finally, three numerical examples, including scatting, transmission, and radiation, are also provided to validate its running time, unconditional stability, and absorption characteristic. [ABSTRACT FROM AUTHOR]

Aim: To investigate the effects of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) deficiency on the cytotoxicity of chemotherapeutic agents toward colorectal cancer cells., Methods: PTEN-deficient colorectal cancer (CRC) cells were generated by human somatic cell gene targeting using the adeno-associated virus system. The cytotoxic effects of compounds including curcumin, 5-fluorouracil (5-FU), dihydroartemisinin (DHA), irinotecan (CPT-11) and oxaliplatin (OXA) on cancer cells were determined using the MTT assay. Enhanced cytotoxicity of curcumin in PTEN-deficient CRC cells was observed, and this was confirmed using clonogenic assays. Apoptosis and cell cycle progression were analyzed by flow cytometry. Levels of apoptosis and cell cycle-related proteins were examined by Western blotting., Results: We developed an isogenic set of CRC cell lines that differed only in their PTEN status. Using this set of cell lines, we found that disruption of the PTEN gene had no effect on the sensitivity of CRC cells to 5-FU, CPT-11, DHA, or OXA, whereas PTEN disruption increased the sensitivity of CRC cells to curcumin. Loss of PTEN did not alter the curcumin-induced apoptosis in CRC cells. However, PTEN deficiency led to an altered pattern of curcumin-mediated cell cycle arrest. In HCT116 PTEN (+/+) cells, curcumin caused a G2/M phase arrest, whereas it caused a G0/G1 phase arrest in HCT116 PTEN (-/-) cells. Levels of cell cycle-related proteins were consistent with these respective patterns of cell cycle arrest., Conclusion: Curcumin shows enhanced cytotoxicity toward PTEN-deficient cancer cells, suggesting that it might be a potential chemotherapeutic agent for cancers harboring PTEN mutations.

Objective: To analyse the chemical constituents of essential oils from Chrysanthemum indicum collected in Jinyun Mountains., Methods: The essential oil was extracted by steam distillation and analyzed by GC-MS., Results: The GC chromatogram of the essential oil had 92 peaks among which 69 were identified to be 66 compounds whose relative contents summed to account for 90. 07% of the total essential oil., Conclusion: It indicates Chrysanthemum indicum in Jinyun Mountains is good as medicine or for food. The place of origin has obvious influence on the chemical compostions of Chrysanthemum indicum's essential oil.