Effectiveness of social media-assisted course on learning self-efficacy.

The social media platform and the information dissemination revolution have changed the thinking, needs, and methods of students, bringing development opportunities and challenges to higher education. This paper introduces social media into the classroom and uses quantitative analysis to investigate the relation between design college students' learning self-efficacy and social media for design students, aiming to determine the effectiveness of social media platforms on self-efficacy. This study is conducted on university students in design media courses and is quasi-experimental, using a randomized pre-test and post-test control group design. The study participants are 73 second-year design undergraduates. Independent samples t-tests showed that the network interaction factors of social media had a significant impact on college students learning self-efficacy. The use of social media has a significant positive predictive effect on all dimensions of learning self-efficacy. Our analysis suggests that using the advantages and value of online social platforms, weakening the disadvantages of the network, scientifically using online learning resources, and combining traditional classrooms with the Internet can improve students' learning self-efficacy.

Isolation and Biological Evaluation of Alfa-Mangostin as Potential Therapeutic Agents against Liver Fibrosis.

The increased proliferation and activation of hepatic stellate cells (HSCs) are associated with liver fibrosis development. To date, there are no FDA-approved drugs for the treatment of liver cirrhosis. Augmentation of HSCs apoptosis is one of the resolutions for liver fibrosis. In this study, we extracted α-mangostin (1,3,6-trihydroxy-7-methoxy-2,8-bis(3-methyl-2-butenyl)-9H-xanthen-9-one) from the fruit waste components of mangosteen pericarp. The isolated α-mangostin structure was determined and characterized with nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS) and compared with those known compounds. The intracellular signaling pathway activities of α-mangostin on Transforming growth factors-beta 1 (TGF-ß1) or Platelet-derived growth factor subunit B (PDGF-BB) induced HSCs activation and were analyzed via Western blot and Real-time Quantitative Polymerase Chain Reaction (Q-PCR). α-Mangostin-induced mitochondrial dysfunction and apoptosis in HSCs were measured by seahorse assay and caspase-dependent cleavage. The in vivo anti-fibrotic effect of α-mangostin was assessed by carbon tetrachloride (CCl4) treatment mouse model. The data showed that α-mangostin treatment inhibited TGF-ß1-induced Smad2/3 phosphorylation and alpha-smooth muscle actin (α-SMA) expression in HSCs in a dose-dependent manner. Regarding the PDGF-BB-induced HSCs proliferation signaling pathways, α-mangostin pretreatment suppressed the phosphorylation of extracellular-signal-regulated kinase (ERK) and p38. The activation of caspase-dependent apoptosis and dysfunction of mitochondrial respiration (such as oxygen consumption rate, ATP production, and maximal respiratory capacity) were observed in α-mangostin-treated HSCs. The CCl4-induced liver fibrosis mouse model showed that the administration of α-mangostin significantly decreased the expression of the fibrosis markers (α-SMA, collagen-a2 (col1a2), desmin and matrix metalloproteinase-2 (MMP-2)) as well as attenuated hepatic collagen deposition and liver damage. In conclusion, this study demonstrates that α-mangostin attenuates the progression of liver fibrosis through inhibiting the proliferation of HSCs and triggering apoptosis signals. Thus, α-mangostin may be used as a potential novel therapeutic agent against liver fibrosis.

The effects of additive manufacturing technologies and finish line designs on the trueness and dimensional stability of 3D-printed dies.

PURPOSE: To evaluate the effects of 5 manufacturing technologies and 2 finish line designs on the trueness and dimensional stability of 3D-printed definitive dies at finish line regions under different storage conditions and time. MATERIAL AND METHODS: Preparation of light chamfer and round shoulder finish lines were adopted individually on two mandibular first molar typodont teeth and digitalized as standard tessellation language (STL) files. A total of 240 samples (192 AM definitive dies and 48 definitive conventional stone dies) in 20 groups (n = 12) were manufactured based on 2 finishing line designs (chamfer and shoulder), 5 manufacturing technologies (4 additively manufactured technologies and conventional stone die), and 2 storage conditions (light exposure and dark). The 4 additively manufactured (AM) technologies include a DLP 3D-printer, an economic LED 3D-printer, a CLIP 3D-printer, and an SLA 3D-printer. All the study samples were distributed into two storage conditions. Subsequently, samples were digitalized to STL files at 3 different time points (within 36 hours, 1-month, and 3-months). A surface matching software was used to superimpose the sample STL files onto the corresponding original STL files with the best-fit alignment function. The trueness of each printed and stone definitive dies and their dimensional stabilities were measured by the root mean square (RMS, in mm). A linear mixed-effects model was used to test the effects of the finish line design, manufacturing technology, storage condition, and storage time on RMS values (α = 0.05). RESULTS: While finish line designs had no significant effects [F(1, 220) = 0.85, p < 0.358], the manufacturing technologies [F(3, 220) = 33.02, p < 0.001], storage condition [F(1, 220) = 4.11, p = 0.044], and storage time F(2, 440) = 10.37, p < 0.001] affected the trueness and dimensional stability of 3D-printed dies at finish line regions. No significant interactions were found among the 4 factors. For the manufacturing technologies, Type IV stone groups and LCD 3D-printer groups had significantly higher RMS values than the other 3 printers (p < 0.001) with no significant differences between Type IV stone and LCD 3D-printer groups (p = 0.577). DLP 3D-printer groups had higher RMS values than both SLA 3D-printer groups and CLIP 3D-printer groups (p < 0.001). There were no significant differences between SLA 3D-printer groups and CLIP 3D-printer groups, p = 0.671. For the effects of storage conditions, RMS values were significantly higher in the groups stored with the direct light exposure than the ones stored in the dark, p = 0.044. In terms of the effects of storage time, the RMS values were significantly higher after 1-month storage, p = 0.002; and 3-month storage, p < 0.001, than the ones at the immediate postmanufacturing stage. However, the RMS values after 1-month and 3-month storage were not significantly different from each other (p = 0.169). CONCLUSIONS: Manufacturing technologies, storage conditions, and storage time significantly affected the trueness and dimensional stability of 3D-printed dies at finish line regions, while finish line designs had no significant effects. Among the AM technologies tested, all have produced either comparable or truer 3D-printed dies than the Type IV dental stone dies, and the CLIP and SLA 3D-printers produced the best outcomes. 3D-printed dies showed significant distortion after 1-month and 3-months storage, especially under light exposure storage conditions. These findings may negate the clinical need to preserve 3D-printed dies, and digital data should be preserved instead.

Nanoscale-cavity enhancement of color conversion with colloidal quantum dots embedded in the surface nano-holes of a blue-emitting light-emitting diode.

Although the method of inserting colloidal quantum dots (QDs) into deep nano-holes fabricated on the top surface of a light-emitting diode (LED) has been widely used for producing effective Förster resonance energy transfer (FRET) from the LED quantum wells (QWs) into the QDs to enhance the color conversion efficiency, an important mechanism for enhancing energy transfer in such an LED structure was overlooked. This mechanism, namely, the nanoscale-cavity effect, represents a near-field Purcell effect and plays a crucially important role in enhancing the color conversion efficiency. Here, we demonstrate the results of LED performance, time-resolved photoluminescence (TRPL), and numerical simulation to elucidate the nanoscale-cavity effect on color conversion by inserting a photoresist solution of red-emitting QDs into the nano-holes fabricated on a blue-emitting QW LED. Based on the TRPL study of the inserted QDs in a nano-hole structure fabricated on an un-doped GaN template of no QW, it is found that the emission efficiency of the inserted QDs is significantly increased due to the nanoscale-cavity effect. From the simulation study, it is confirmed that this effect can also increase the FRET efficiency, particularly for those radiating dipoles in the QWs oriented perpendicular to the sidewalls of the nano-holes. In the nanoscale-cavity effect, the enhanced near field distribution inside a nano-hole excited by a light emitter modifies its own radiation behavior through the Purcell effect such that its far-field emission becomes stronger.

Distortion-free femtosecond laser inscription in free-standing optical fiber.

In this paper, we report the first experimental demonstration, to the best of our knowledge, of low-energy distortion-free femtosecond laser inscription in a free-standing fiber without the need for oil immersion. The methodology proposed features radial-plane beam shaping to eliminate the focal-point distortion induced by the cylindrical geometry of the fiber, thus achieving optimal focusing and spot-like inscription within the fiber. Based on the proposed methodology, a strong, first-order fiber Bragg grating is achieved for the first time, to the best of our knowledge, in a coated free-standing single-mode fiber by using the point-by-point inscription technique with only 50 nJ laser pulse energy.

Realization of ultrafast all-optical switching with switching gain in a single semiconductor waveguide.

In this Letter, we report for the first time to our knowledge that all-optical switching gain can be achieved with a dual-wavelength control versus pump beam scheme in a single semiconductor waveguide structure. That means a weak optical beam can switch a strong optical beam. Moreover, a high switching speed of 10-100 Gb/s can be achieved. The all-optical switching is simulated numerically via a multilevel multielectron (MLME) FDTD program capable of modeling complex semiconductor band properties. It is shown that a weak control/input-signal beam at a longer wavelength is able to switch the transmission of a strong pump/output-signal beam at a shorter wavelength. A 50 Gbps and 0.5 pJ per bit switching operation with switching gain of around 10 is shown for a 40 µm-long waveguide with pump beam power around 20 mW based on bulk InGaAsP material and a 300 nm×300 nm waveguide (the control beam power is 1/10 of that for the pump).

CD44 gene polymorphisms and environmental factors on oral cancer susceptibility in Taiwan.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is the fourth leading cause of male cancer death in Taiwan. Exposure to environmental carcinogens is the primary risk factor for developing OSCC. CD44, a well-known tumor marker, plays a crucial role in tumor cell differentiation, invasion, and metastasis. This study investigated CD44 single-nucleotide polymorphisms (SNPs) with environmental risk factors to determine OSCC susceptibility and clinicopathological characteristics. METHODOLOGY/PRINCIPAL FINDINGS: Real-time polymerase chain reaction (PCR) was used to analyze 6 SNPs of CD44 in 599 patients with oral cancer and 561 cancer-free controls. We determined that the CD44 rs187115 polymorphism carriers with the genotype AG, GG, or AG+GG were associated with oral cancer susceptibility. Among 731 smokers, CD44 polymorphisms carriers with the betel-nut chewing habit had a 10.30-37.63-fold greater risk of having oral cancer compared to CD44 wild-type (WT) carriers without the betel-nut chewing habit. Among 552 betel-nut chewers, CD44 polymorphisms carriers who smoked had a 4.23-16.11-fold greater risk of having oral cancer compared to those who carried the WT but did not smoke. Finally, we also observed that the stage III and IV oral cancer patients had higher frequencies of CD44 rs187115 polymorphisms with the variant genotype (AG+GG) compared with the wild-type (WT) carriers. CONCLUSION: Our results suggest that gene-environment interactions between the CD44 polymorphisms and betel quid chewing and tobacco smoking increase the susceptibility to oral cancer development. Patients with CD44 rs187115 variant genotypes (AG+GG) were correlated with a higher risk of oral cancer development, and these patients may possess greater chemoresistance to advanced- to late-stage oral cancer than WT carriers do. The CD44 rs187115 polymorphism has potential predictive significance in oral carcinogenesis and also may be applied as factors to predict the clinical stage in OSCC patients.

Laser-assisted lateral optical fiber processing for selective infiltration.

We propose a new technique to perform precise selective infiltration of an air hole in the photonic crystal fiber (PCF). To carry out the infiltration process, the end face of the PCF is covered by a mask, which is fabricated by femtosecond laser inscription from the lateral direction. This proposed method overcomes the conventional limitation of maximum mask thickness. An analytical model is further proposed and demonstrated accurate determinations of the fabricated channel diameter in the mask.

Demonstration of heterogeneous III-V/Si integration with a compact optical vertical interconnect access.

Heterogeneous III-V/Si integration with a compact optical vertical interconnect access is fabricated and the light coupling efficiency between the III-V/Si waveguide and the silicon nanophotonic waveguide is characterized. The III-V semiconductor material is directly bonded to the silicon-on-insulator (SOI) substrate and etched to form the III-V/Si waveguide for a higher light confinement in the active region. The compact optical vertical interconnect access is formed through tapering a III-V and an SOI layer in the same direction. The measured III-V/Si waveguide has a light coupling efficiency above ~90% to the silicon photonic layer with the tapering structure. This heterogeneous and light coupling structure can provide an efficient platform for photonic systems on chip, including passive and active devices.

CMOS compatible integration of Si/SiO2 multilayer GRIN lens optical mode size converter to Si wire waveguide.

We present a CMOS compatible mass manufacturable, compact Si/SiO(2) multilayer GRIN lens mode size converter from standard single mode fiber to 300 nm-thick Si waveguide. The fiber-to-GRIN lens coupling loss is 2.6 ± 0.3 dB (coupling efficiency: 51~60%) with optimized focal length of 11.6~11.8 µm and Si/SiO(2) multilayer thickness of 7.4 µm.

In situ molecular detection of ischemic cells by enhanced protein direct electron transfer on a unique horseradish peroxidase-Au nanoparticles-polyaniline nanowires biofilm.

To overcome shortcomings of the ex situ approaches, in situ detection using H(2)O(2) molecules to diagnose ischemia through enhanced protein direct electron transfer on a unique horseradish peroxidase-Au nanoparticles-polyaniline nanowires biofilm is demonstrated and it is discovered that the extracellular H(2)O(2) molecule released per ischemic cell is 2.7-times of that of a normal cell.

Ultra-compact multilayer Si/SiO(2) GRIN lens mode-size converter for coupling single-mode fiber to Si-wire waveguide.

We report on the fabrication and experimental demonstration of optical mode size transformation between standard single-mode fiber and 0.26 µm-thick Si-waveguide by 12 µm-thick Si/SiO(2) multilayer on-chip GRIN lens of lengths 16 µm or 24 µm butt-joint to 10 µm-wide terminated Si-waveguide. The overall coupling loss of the coupler was measured to be 3.45 dB in which the Fresnel reflection loss is estimated to be 2dB at the GRIN-lens/air interface. The on-chip integrated GRIN lens opens up the feasibility of a low cost passive aligned fiber-pigtailed electronic-photonics integrated circuits platform.

Near-field nanoimaging by nanoscale photodetector array.

We report a demonstration of near-field nanoimaging using nanoscale photodetector (NPD) array. The NPD array has detector pixels with subwavelength dimension and is capable of pixel addressing. An active-media finite-difference time-domain simulation of the NPD array shows an imaging resolution of 150 nm for 1.55 microm light. Additionally, we demonstrate the realization and characterization of the NPD array. The smallest NPD array obtained has 100-nm-wide pixels with 100 nm spacing. A responsivity of 0.28 A/W at 1.31 microm and 3.3 V bias is registered for a 2x2 NPD array pixel. The corresponding photocurrent is 735 nA with a dark current of 0.483 nA. Using near-field photocurrent microscopy, an imaging resolution of 390 nm has been demonstrated.

In-fiber polymer-glass hybrid waveguide Bragg grating.

A 1.2 microm (height) x 125 microm (depth) x 500 microm (length) microslot along a fiber Bragg grating was engraved across the optical fiber by femtosecond laser patterning and chemical etching. By filling epoxy in the slot and subsequent UV curing, a hybrid waveguide grating structure with a polymer core and glass cladding was fabricated. The obtained device is highly thermally responsive with linear coefficient of 211 pm/ degrees C.

Numerical and experimental study of microfluidic devices in step-index optical fibers.

Microfluidic devices composed of microslits in step-index optical fibers are thoroughly investigated. Numerical simulations are performed to explain scattering and power loss in such devices. Experimental results based on microslits fabricated by femtosecond laser processing corroborate theoretical data. Dependency of the device performance on the refractive index of fluid in the slit is further utilized to construct a refractive index sensor and an in-fiber attenuator.

A refractometer based on a micro-slot in a fiber Bragg grating formed by chemically assisted femtosecond laser processing.

A liquid core waveguide as a refractometer is proposed. Microtunnels were created in standard optical fiber using tightly focused femtoscond laser inscription and chemical etching. A 1.2(h)x125(d) x500(l) mum micro-slot engraved along a fiber Bragg grating (FBG) was used to construct liquid core waveguide by filling the slot with index matching oils. The device was used to measure refractive index and sensitivity up to 10- 6/pm was obtained.

Optically tunable fiber grating transmission filters.

We propose and demonstrate single- and multiple-passband fiber grating transmission filters that are remotely tunable by exploitation of the optical pump-induced thermal effects in Er/Yb-codoped fiber sections. A repeatable, wavelength-independent induced phase shift of 0.1 pi/mW is obtained without hysteresis and anisotropic effects. A transmission extinction ratio of >23 dB with a 3-mW change in pump power is achieved.