Student-teacher communication preferences in Taiwanese older learners.

The role of teacher-student communication in enhancing the learning experience of older learners has received limited attention. This sociolinguistic study addresses this gap by examining the perspectives on this issue held by Taiwanese older learners. Survey data from 231 Taiwanese older learners were analyzed using ANOVA and independent-samples t-tests, with the aim of establishing how their age ranges and occupational backgrounds influenced their concordance with teacher communication strategies found in existing literature. While teachers were reported to assume that older learners from elite backgrounds preferred more communication accommodation in class, this study's results indicated that those with no work experience or who identified as farmers demanded greater respect, flexibility, and diversity of language codes. Age was also significantly correlated with learners' communication preferences, with those aged 76+ requiring more extensive accommodations than their younger counterparts did.

Molecular mechanisms of discrotophos-induced toxicity in HepG2 cells: The role of CSA in oxidative stress.

Dicrotophos (Dic), an insecticide and acaricide, is used against a variety of sucking, boring and chewing pests. It was proven that Dic induced oxidative DNA damage in HepG2 cells. However, the molecular mechanisms of this compound were still unclear. First of all, the cytotoxicity and oxidative DNA damage were confirmed. Next, using RNA-seq for detecting differential expressed genes (DEGs) in cells treated with 50 µM Dic for 24 h, we showed that the dysregulation of these genes, irrespective of up (1298 genes) or down (2125 genes) regulation, could be attributed to some diverse pathways/metabolisms using KEGG analysis, particularly in DNA damage responses (DDRs) such as oxidative phosphorylation, nucleotide excision repair and cell cycle arrest. Validation of some randomly selected DDR genes confirmed RNA-seq results. We further demonstrated that Dic induced ROS overproduction, the loss of mitochondrial depolarization and cell cycle arrest in the G0/G1 phase. In addition, we also definitely clarified the role of CSA, a nucleotide excision repair enzymes in Dic-treated cells. Collectively, our results showed that various mechanisms of Dic-induced toxicity in HepG2 cells including downregulation of some genes related to nucleotide excision repair including CSA and increased oxidative stress.

Litchi seed extract inhibits epidermal growth factor receptor signaling and growth of Two Non-small cell lung carcinoma cells.

BACKGROUND: Litchi seeds possess rich amounts of phenolics and have been shown to inhibit proliferation of several types of cancer cells. However, the suppression of EGFR signaling in non-small cell lung cancer (NSCLC) by litchi seed extract (LCSE) has not been fully understood. METHODS: In this study, the effects of LCSE on EGFR signaling, cell proliferation, the cell cycle and apoptosis in A549 adenocarcinoma cells and NCI- H661 large-cell carcinoma cells were examined. RESULTS: The results demonstrated that LCSE potently reduced the number of cancer cells and induced growth inhibition, cell-cycle arrest in the G1 or G2/M phase, and apoptotic death in the cellular experiment. Only low cytotoxicity effect was noted in normal lung MRC-5 cells. LCSE also suppressed cyclins and Bcl-2 and elevated Kip1/p27, Bax and caspase 8, 9 and 3 activities, which are closely associated with the downregulation of EGFR and its downstream Akt and Erk-1/-2 signaling. CONCLUSION: The results implied that LCSE suppressed EGFR signaling and inhibited NSCLC cell growth. This study provided in vitro evidence that LCSE could serve as a potential agent for the adjuvant treatment of NSCLC.

Crosstalk analysis of ring resonator switches for all-optical routing.

Optical switches based on ring resonator cavities were fabricated by a silicon photonics foundry process and analyzed for optical crosstalk at various data rates and channel spacings. These devices were compared to commercial bandpass filters and at 20Gb/s, 0.5dB power penalty is observed due to spectral filtering for bit error ratio threshold of 1 × 10-9. Concurrent modulation at 20Gb/s with a channel spacing as narrow as 40GHz shows error-free transmission with 1dB power penalty as compared to wider channel spacing for the ring-based switch.

A comb laser-driven DWDM silicon photonic transmitter based on microring modulators.

We demonstrate concurrent multi-channel transmission at 10 Gbps per channel of a DWDM silicon photonic transmitter. The DWDM transmitter is based on a single quantum dot comb laser and an array of microring resonator-based modulators. The resonant wavelengths of microrings are thermally tuned to align with the wavelengths provided by the comb laser. No obvious crosstalk is observed at 240 GHz channel spacing.

Advertising Representations of Older People in the United Kingdom and Taiwan: A Comparative Analysis.

Cross-cultural studies of advertising representations of older people are relatively scarce. This article aims to fill in this gap via a comparison between Taiwan and the United Kingdom, employing a combination of quantitative content analysis and the qualitative grounded theory method. The content-analysis phase reveals underrepresentation of older people in both countries' advertising contexts, as well as representational differences between Taiwan and the United Kingdom in terms of older characters' role salience, the products, physical settings, and social networks they are associated with. The grounded-theory phase yields nine prototypes of older people along with subcategories to conceptualize the qualities of older people as they appear in TV ads in these countries. The findings are discussed in relation to the stereotyping of older people and transformed into hypothetical statements to be modified in future research. In conclusion, the Confucian tradition of filial piety is still found to be important in explaining the observed cross-cultural differences, but the emergence of new norms about aging in Taiwanese advertising also suggests that this tradition may be in decline.

Compact models for carrier-injection silicon microring modulators.

We propose compact DC and small-signal models for carrier-injection microring modulators that accurately describe the DC characteristics (resonance wavelength, quality factor, and extinction ratio) and the high frequency performance. The proposed theoretical models provide physical insights of the carrier-injection microring modulators with a variety of designs. The DC and small-signal models are implemented in Verilog-A for SPICE-compatible simulations.

Error-free DWDM transmission and crosstalk analysis for a silicon photonics transmitter.

Individual channels of a five-channel microring silicon photonics transmitter are used for bit error ratio analysis and demonstrate error-free transmission at 10Gb/s. Two channels of the same transmitter are concurrently modulated using an 80GHz channel spacing comb laser and demonstrate open eye diagrams at 10Gb/s and 12.5Gb/s. Finally, concurrent modulation with tunable lasers is done to quantify optical power penalty for link bit error ratio versus channel spacing from +100GHz to -100GHz. When using a comb laser for concurrent modulation, no direct power penalty is observed for an 80GHz channel separation.

MicroRNA regulation of DNA repair gene expression in 4-aminobiphenyl-treated HepG2 cells.

We examined the role of miRNAs in DNA damage response in HepG2 cells following exposure to 4-aminobiphenyl (4-ABP). The arylamine 4-ABP is a human carcinogen. Using the Comet assay, we showed that 4-ABP (18.75-300µM) induces DNA damage in HepG2 cells after 24h. DNA damage signaling pathway-based PCR arrays were used to investigate expression changes in genes involved in DNA damage response. Results showed down-regulation of 16 DNA repair-related genes in 4-ABP-treated cells. Among them, the expression of selected six genes (UNG, LIG1, EXO1, XRCC2, PCNA, and FANCG) from different DNA repair pathways was decreased with quantitative real-time PCR (qRT-PCR). In parallel, using the miRNA array, we reported that the expression of 27 miRNAs in 4-ABP-treated cells was at least 3-fold higher than that in the control group. Of these differential 27 miRNAs, the most significant expression of miRNA-513a-5p and miRNA-630 was further validated by qRT-PCR, and was predicted to be implicated in the deregulation of FANCG and RAD18 genes, respectively, via bioinformatic analysis. Both FANCG and RAD18 proteins were found to be down-regulated in 4-ABP-treated cells. In addition, overexpression and knockdown of miRNA-513a-5p and miRNA-630 reduced and increased the expression of FANCG and RAD18 proteins, respectively. Based on the above results, we indicated that miRNA-513a-5p and miRNA-630 could play a role in the suppression of DNA repair genes, and eventually lead to DNA damage.

Effects of ellagic acid on chemosensitivity to 5-fluorouracil in colorectal carcinoma cells.

Ellagic acid has been demonstrated to inhibit the growth of several types of cancer cells. However, whether it sensitizes human colorectal carcinoma cells to 5-fluorouracil, has not yet been investigated. Colorectal carcinoma HT-29, Colo 320DM, SW480 and LoVo cells were treated with ellagic acid (2.5-25 µg/ml) and 5-fluorouracil (5-25 µM) alone and in combination and then the viability was assessed by trypan blue exclusion, apoptosis by annexin-V labeling, mitochondria membrane potential by staining with rhodamine 123, and changes in the levels of proteins involved in apoptosis by immunoblotting. Ellagic acid and 5-fluorouracil synergistically inhibited cell proliferation of HT-29, Colo 320DM and SW480 cells, but cytotoxicity toward LoVo cells seems not to be potentiated by this combination. The combination also elevated apoptotic cell death of HT-29 and Colo 320DM cells. The mitochondria membrane potential was lost in combination-treated HT-29 cells, due to increased B cell lymphoma 2-associated protein X (BAX): B cell lymphoma 2 protein (BCL-2) ratio and caspase-3 activity. Ellagic acid synergistically potentiated chemosensitivity to 5-fluorouracil in at least three colorectal cancer cell lines. The results indicate that ellagic acid has potential as a novel agent sensitizing colorectal cancer cells to 5-fluorouracil.

Narrow linewidth operation of buried-heterostructure photonic crystal nanolaser.

We investigate the spectral linewidth of a monolithic photonic crystal nanocavity laser. The nanocavity laser is based on a buried heterostructure cavity in which an ultra-small InGaAsP active region is embedded in an InP photonic crystal. Although it was difficult to achieve narrow linewidth operation in previously reported photonic crystal nanocavity lasers, we have successfully demonstrated a linewidth of 143.5 MHz, which is far narrower than the cold cavity linewidth and the narrowest value yet reported for nanolasers and photonic crystal lasers. The narrow linewidth is accompanied by a low power consumption and an ultrasmall footprint, thus making this particular laser especially suitable for use as an integrated multi-purpose sensor.

Grape-seed procyanidins inhibit the in vitro growth and invasion of pancreatic carcinoma cells.

OBJECTIVES: Grape-seed procyanidins (GSPs) can inhibit cell proliferation and invasiveness in various human cancers. However, the effect of GSP on pancreatic carcinoma cells has not been investigated. METHODS: Pancreatic carcinoma cell lines MIA PaCa-2 and BxPC-3 treated with GSP were assessed for viability by trypan blue exclusion, for cell cycle distribution by flow cytometry, for increased apoptosis by annexin V labeling, for their adhesion and invasion potential by evaluating their ability to penetrate through a matrix gel-coated Boyden chamber, and for changes in the levels of proteins involved in cellular events by immunoblotting. RESULTS: Grape-seed procyanidin inhibited MIA PaCa-2 and BxPC-3 proliferation in a dose-dependent manner and induced G1-phase arrest of the cell cycle in BxPC-3 or mitochondria-mediated apoptosis in MIA PaCa-2. Grape-seed procyanidin also inhibited the adhesion and invasion potential of both cell lines in a dose-dependent manner, which are associated with the suppression of metalloproteases matrix metalloproteinase 9 or 2 (MMP-9 or -2) expression. CONCLUSIONS: Grape-seed procyanidin inhibited the proliferation of pancreatic carcinoma cells by cell cycle blockage or apoptotic induction. The invasiveness was also suppressed by GSP through down-regulation of MMP-2 or MMP-9 in pancreatic carcinoma cells. Grape-seed procyanidin is a potential chemotherapeutic or preventive agent for pancreatic carcinoma.

40-Gb/s directly-modulated photonic crystal lasers under optical injection-locking.

CMOS integrated circuits (IC) usually requires high data bandwidth for off-chip input/output (I/O) data transport with sufficiently low power consumption in order to overcome pin-count limitation. In order to meet future requirements of photonic network interconnect, we propose an optical output device based on an optical injection-locked photonic crystal (PhC) laser to realize low-power and high-speed off-chip interconnects. This device enables ultralow-power operation and is suitable for highly integrated photonic circuits because of its strong light-matter interaction in the PhC nanocavity and ultra-compact size. High-speed operation is achieved by using the optical injection-locking (OIL) technique, which has been shown as an effective means to enhance modulation bandwidth beyond the relaxation resonance frequency limit. In this paper, we report experimental results of the OIL-PhC laser under various injection conditions and also demonstrate 40-Gb/s large-signal direct modulation with an ultralow energy consumption of 6.6 fJ/bit.

Induction of DNA damage signaling genes in benzidine-treated HepG2 cells.

We examined genotoxicity and DNA damage response in HepG2 cells following exposure to benzidine. Using the Comet assay, we showed that benzidine (50-200 µM) induces DNA damage in HepG2 cells. DNA damage signaling pathway-based PCR arrays were used to investigate expression changes in genes involved in cell-cycle arrest, apoptosis, and DNA repair and showed upregulation of 23 genes and downregulation of one gene in benzidine-treated cells. Induction of G2/M arrest and apoptosis was confirmed at the protein level. Real-time PCR and Western blots were used to demonstrate the expression of select DNA repair-associated genes from the PCR array. Upregulation of the p53 protein in benzidine-treated cells suggests the induction of the p53 DNA damage signaling pathway. Collectively, DNA damage response genes induced by benzidine indicate recruitment complex molecular machinery involved in DNA repair, cell-cycle arrest, and potentially, activation of the apoptosis.

20-Gbit/s directly modulated photonic crystal nanocavity laser with ultra-low power consumption.

We have demonstrated an ultracompact buried heterostructure photonic crystal (PhC) laser, consisting of an InGaAsP-based active region (5.0 x 0.3 x 0.15 µm3) buried in an InP layer. By employing a buried heterostructure with an InP layer, we can greatly improve thermal resistance and carrier confinement. We therefore achieved a low threshold input power of 6.8 µW and a maximum output power in the output waveguide of -10.3 dBm by optical pumping. The output light is effectively coupled to the output waveguide with a high external differential quantum efficiency of 53%. We observed a clear eye opening for a 20-Gbit/s NRZ signal modulation with an absorbed input power of 175.2 µW, resulting in an energy cost of 8.76 fJ/bit. This is the smallest reported energy cost for any type of semiconductor laser.

All-optical memory based on injection-locking bistability in photonic crystal lasers.

We have demonstrated an all-optical memory by using InGaAsP/InP buried heterostructure photonic crystal (BH-PhC) lasers. We achieved distinct optical injection locking bistability in an ultra-compact active region (4 × 0.3 × 0.16 µm3) with only 25 µW pump power in the PhC waveguide, which is two orders less than previously reported optical memories based on other bistable semiconductor lasers. Dynamic memory operations were achieved with pump power of 100 µW and switching power of 22 µW and 71 µW in the PhC waveguide. Fast switching times of about 60 ps were achieved. To the authors' best knowledge, this is the first demonstration of PhC laser-based all-optical memory.

Cytotoxic steroidal saponins from Agave sisalana.

Two new steroidal saponins, 8 and 10, along with 7 known steroidal sapogenins and saponins (1-7) and a furostanol saponin (9) were isolated from Agave sisalana Perrine ex Engelm. The structures of these two new compounds were identified and characterized by 1D and 2D NMR spectroscopy and mass spectrometry. In addition, acid hydrolysis and GC-FID were used to confirm the sugar moieties of 8 and 10. The cytotoxic effects of 1-10 on MCF-7, NCI-H460, and SF-268 cancer cells were evaluated, and among them, compound 10 proved to be the most cytotoxic with IC50 values of 1.2, 3.8, and 1.5 µM, respectively.

Mediating effects of emotional exhaustion on the relationship between job demand­control model and mental health.

This study attempted to investigate the role of emotional exhaustion as a mediator on the relationship between job demands-control (JDC) model and mental health. Three-wave data from 297 employees were collected. The results showed that job demands were positively related to emotional exhaustion, and increasing job demands will increase the level of emotional exhaustion. Job control was negatively associated with emotional exhaustion; therefore, increasing job control will decrease the level of emotional exhaustion. Emotional exhaustion was negatively related to mental health. Emotional exhaustion fully mediated the relationship between job demands and mental health, and partially mediated the positive relationship between job control and mental health. In addition, job control was positively associated with mental health directly. The remarkable finding of the present study was that emotional exhaustion served as the key mediator between the JDC model and mental health. Theoretical and managerial implications and limitations were discussed.

Compact beam splitters with deep gratings for miniature photonic integrated circuits: design and implementation aspects.

We present an extensive study of an ultracompact grating-based beam splitter suitable for photonic integrated circuits (PICs) that have stringent density requirements. The 10 microm long beam splitter exhibits equal splitting, low insertion loss, and also provides a high extinction ratio in an integrated coherent balanced receiver. We further present the design strategies for avoiding mode distortion in the beam splitter and discuss optimization of the widths of the detectors to improve insertion loss and extinction ratio of the coherent receiver circuit. In our study, we show that the grating-based beam splitter is a competitive technology having low fabrication complexity for ultracompact PICs.

Antioxidant activity of some plant extracts towards xanthine oxidase, lipoxygenase and tyrosinase.

Natural products have the potential to be developed into new drugs for the treatment of various diseases. The aim of the present study was to screen the antioxidant activities of some common edible fruits, garden plants and medicinal plants indigenous to Taiwan. This was performed by assessing the activities of lipoxygenase, xanthine oxidase and tyrosinase following incubation with extracts from these plants. A further aim was to use HPLC-DAD and tyrosinase to chromatographically identify the antioxidative constituents obtained from an extract exhibiting strong antioxidative properties. The acetone extracts of 27 cultivated plant species from Taiwan were tested for antioxidant activities towards xanthine oxidase, tyrosinase and lipoxygenase using spectrophotometric assays. Koelreuteria henryi, Prunus campanulata, and Rhodiola rosea showed the highest xanthine oxidase inhibitory activities. Camellia sinensis, Rhodiola rosea, and Koelreuteria henryi exhibited good tyrosinase inhibitory activities and potent anti-lipoxygenase activities. As Koelreuteria henryi had notable significant inhibitory activities towards xanthine oxidase, tyrosinase, and lipoxygenase, it was further tested with tyrosinase and HPLC-DAD. The results from this part of the study revealed that the more powerful the antioxidant capability of the extracted component, the greater the decrease in peak height obtained after reacting with tyrosinase. Additional studies are warranted to further characterize the compounds responsible for the antioxidant properties of the examined extracts.