In Situ Redox Synthesis of Highly Stable Au/Electroactive Polyimide Composite and Its Application on 4-Nitrophenol Reduction.

In this study, we developed a series of Au/electroactive polyimide (Au/EPI-5) composite for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) using NaBH4 as a reducing agent at room temperature. The electroactive polyimide (EPI-5) synthesis was performed by chemical imidization of its 4,4'-(4.4'-isopropylidene-diphenoxy) bis (phthalic anhydride) (BSAA) and amino-capped aniline pentamer (ACAP). In addition, prepare different concentrations of Au ions through the in-situ redox reaction of EPI-5 to obtain Au nanoparticles (AuNPs) and anchored on the surface of EPI-5 to form series of Au/EPI-5 composite. Using SEM and HR-TEM confirm the particle size (23-113 nm) of the reduced AuNPs increases with the increase of the concentration. Based on CV studies, the redox capability of as-prepared electroactive materials was found to show an increase trend: 1Au/EPI-5 < 3Au/EPI-5 < 5Au/EPI-5. The series of Au/EPI-5 composites showed good stability and catalytic activity for the reaction of 4-NP to 4-AP. Especially, the 5Au/EPI-5 composite shows the highest catalytic activity when applied for the reduction of 4-NP to 4-AP within 17 min. The rate constant and kinetic activity energy were calculated to be 1.1 × 10-3 s-1 and 38.9 kJ/mol, respectively. Following a reusability test repeated 10 times, the 5Au/EPI-5 composite maintained a conversion rate higher than 95%. Finally, this study elaborates the mechanism of the catalytic reduction of 4-NP to 4-AP.

Sputtered anti-reflection layer on transparent polyimide - substrate improves adhesion strength to - copper layer: effects of layer thickness and sputtering power.

In order to shield the electronic circuits on a transparent polyimide (PI) substrate, an anti-reflection (AR) layer was deposited on a PI film via DC reactive magnetron sputtering. The effects of sputtering power and thickness of AR layer on the optical property and adhesion strength of the PI were investigated. The composition of the AR layer influences the bonding between layers. Sufficient thickness of the AR layer is essential to strengthen the adhesion between the PI and copper (Cu) layers. The sputtered AR layer on the PI also improves the barrier property for water vapor. The AR layer-sputtered PI substrates remain transparent and exhibit high peel strength to the Cu layer, suggesting their potential applications as reliable transparent substrates for modern electronic devices.

Anti-reflection Layer-Sputtered Transparent Polyimide Substrate with Reliable Adhesion Strength to the Copper Layer.

Parameters of DC-reactive magnetron sputtering are optimized to deposit anti-reflection (AR) layers on transparent polyimide (PI) substrates, followed by the deposition of the conductive copper layer, to fabricate practically reliable composite films as advanced flexible circuits. When the deposition thickness is controlled and the gas composition during sputtering is adjusted, the resultant AR layer-coated PI film exhibits low reflectance and reveals improved adhesion strength to the copper layer. The adhesion reliability tests confirm that the peel strength between the PI film and the deposited layers could be further improved after thermal processing due to the formation of a worm-like morphology for better mechanical interlocking with layers. The facile sputtering process successfully fabricates a reliable substrate material with low reflectance and sufficient adhesion strength to copper for application as flexible printed circuits.

Art therapy for terminal cancer patients in a hospice palliative care unit in Taiwan.

OBJECTIVE: Even though terminal cancer patients receive help from a hospice palliative care team, they have to suffer the pressure of death with deteriorating conditions. This study aims to evaluate the effect of art therapy for these terminal cancer patients. METHOD: The patients involved were terminal cancer patients who were under the care of team members, which included physicians, nurses, social workers, clergy, art therapists, and volunteers in a hospice palliative care unit in Taiwan. The art therapy in our study took the form of visual fine art appreciation and hands-on painting. The effects of the art therapy were evaluated according to patients' feelings, cognitions, and behaviors. RESULTS: There were 177 patients (105 males and 72 females; mean age: 65.4 ±15.8 years) in the study. Each patient received a mean of 2.9 ± 2.0 sessions of the art therapy and produced a mean of 1.8 ± 2.6 pieces of art. During the therapy, most patients described their feelings well, and created art works attentively. Patients expressed these feelings through image appreciation and hands-on painting, among which the landscape was the most common scene in their art. After the therapy, the mean score of patients' artistic expressions (one point to each category: perception of beauty, art appreciation, creativity, hands-on artwork, and the engagement of creating artwork regularly) was 4.0 ± 0.7, significantly higher than the score before therapy (2.2 ± 1.4, p < 0.05). During the therapy, 70% of patients felt much or very much relaxed in their emotional state and 53.1% of patients felt much or very much better physically. SIGNIFICANCE OF RESULTS: Terminal cancer patients in a hospice palliative care unit in Taiwan may benefit from art therapy through visual art appreciation and hands-on creative artwork.

Polyimide-derived graphite barrier layer adhered to seed crystals to improve the quality of grown silicon carbide.

A facial method was developed to in situ fabricate a graphite layer on a SiC seed crystal to reduce the formation of defects during the growth of SiC ingots. The formulated PI matrix combined with an appropriate coupling agent could strongly adhere to SiC and be transformed into protective layers for SiC seed crystals during SiC growth. The thermally conductive graphite layers on SiC effectively reduce the backside diffusion of Si, inhibit the loss of Si from seed crystals during high-temperature growing process, and consequently lead to fewer defects formed in the SiC ingot. The graphitization degree, chemical state, roughness and morphology of films were investigated in this work.

Compatibility enhancement of polyimide-silica hybrid sol-gel materials without incorporation of silane-coupling agent.

A facile route has been developed to enhance compatibility between organic polyimide matrix and dispersed phase of inorganic silica particles without addition of conventional silane-coupling agent. The as-prepared hybrid sol-gel materials having reduced size of SiO2 particle dispersed in polyimide matrix were successfully synthesized through pre-catalyzed sol-gel route using an organic diamine base. The PI-silica hybrid materials through conventional polyamic acid-catalyzed sol-gel route with/without silane-coupling agent were also prepared for comparative control studies. Morphological feature of as-prepared sol-gel materials prepared from three different approaches was also compared based on the studies of transmission electron microscopy. Effects of the material composition, in three different catalyzed routes, were investigated by thermal stability, mechanical strength, optical clarity, gas barrier and water absorption measurements of polyimide and a series of polyimide-silica hybrid sol-gel materials, respectively.

Application of electroactive Au/aniline tetramer-graphene oxide composites as a highly efficient reusable catalyst.

This study proposes a cost-effective, energy-saving, and green process that uses π-π interactions to modify graphene oxide (GO), and the conjugate structure of aniline tetramer (AT) to enhance the dispersion of GO. Au/aniline tetramer-graphene oxide (Au/ATGO) composites were synthesized and applied as a catalyst in this study. The adsorption of AT on GO, via π-π interaction, formed ATGO composites. Subsequently, the amine group on ATGO was stably anchored on Au nanoparticles (Au NPs) to form Au/ATGO composites. The Au/ATGO composites were characterized and the electroactive properties determined by Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, and cyclic voltammetry. The Au/ATGO composites showed excellent performance and stability as catalysts when applied for the reduction of nitrophenol to aminophenol within 225 s and the rate constant was 0.02 s-1. The activation energy for the reduction of 4-NP and 2-NP was 48.10 and 68.71 kJ mol-1, respectively. Following a recycling test repeated 20 times, the Au/ATGO composites maintained a conversion rate higher than 94%.

A Novel Electroactive Imide Oligomer and Its Application in Anticorrosion Coating.

A novel aniline tetramer (AT) capped electroactive imide oligomer (EIO) for metal corrosion protection was successfully synthesized in this study. The chemical structure of the EIO was characterized by liquid chromatography-mass spectrometry and Fourier-transform infrared spectroscopy. Furthermore, the redox behavior of EIO was identified using electrochemical cyclic voltammetry studies. An EIO coated on a cold-rolled steel (CRS) electrode was found to possess superior corrosion resistance to polyimide (PI) on a series of electrochemical corrosion measurements in 3.5 wt.% NaCl solution over an extended period (30 days). The mechanism for the advanced corrosion protection of the PI coating on the CRS electrode could be attributed to the redox catalytic capabilities of the AT units present in the EIO. These capabilities may induce the formation of passive metal oxide layers on the CRS electrode. Scanning electron microscopy and X-ray photoelectron spectroscopy were used to analyze the surface condition of the CRS after the corrosion test. EIO- and PI-coated electrodes were identified by a series of electrochemical measurements, including corrosion potential (Ecorr), polarization resistance (Rp), and corrosion current (Icorr) measurements, along with electrochemical impedance spectroscopy (EIS).

Synthesis and characteristics of multi-walled carbon nanotubes-polyimide nanocomposite films.

The polyimide/multi-walled carbon nanotubes (PI/MWNTs) nanocomposite film has been successfully synthesized in this study. The source of MWNTs is prepared by chemical vapor deposition (CVD) method. Then the MWNTs are washed with acid for purification before being added into the polymer matrix. The acid-modified procedure aids in dispersing MWNTs in N,N-dimethylacetamide (DMAc) solvent. Based on the results of field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM), the MWNTs are embedded in PI and well-dispersed within the PI matrix. The dynamic mechanical analysis (DMA) shows that the storage modulus of nanocomposite film is increased by 68% with the addition of 1 wt% MWNTs into PI. The nanocomposite films start to decompose at or above 400 degrees C and lose 5% of its weight at 545 degrees C according to thermogravimetric analysis (TGA). Meanwhile, the electrical conductivity of the nanocomposite film with 3 wt% MWNTs, is raised more than 10 orders of magnitude from 10(-15) to 10(-5) S/cm.

Flexible and transparent polyimide films containing two-dimensional alumina nanosheets templated by graphene oxide for improved barrier property.

Unique two-dimensional alumina nanosheets (Alns) using graphene oxide (GO) as templates are fabricated and successfully incorporated with organo-soluble polyimide (PI) to obtain highly transparent PI nanocomposite films with improved moisture barrier property. The effects of filler types and contents on water vapor transmission rate (WVTR) and transparency of PI are systematically studied. The hydroxyl groups on GO react with aluminum isopropoxide via sol-gel process to obtain alumina coverd-GO (Al-GO), and then thermal decomposition is applied to obtain Alns. Alns are the most efficient fillers among others to restrict the diffusion of water vapor within PI matrix and simultaneously maintain the transparency of PI. XRD pattern, TEM, and AFM images confirm the sheet-like morphology of Alns with ultrahigh aspect ratio. With only 0.01 wt % of Alns, the PI nanocomposite film exhibits the most significant reduction of 95% in WVTR as compared to that of pure PI film. Most importantly, the resultant PI/Alns-0.01 film exhibits excellent optical transparency and high mechanical strength and great thermal stability.

Flexible polyimide films hybrid with functionalized boron nitride and graphene oxide simultaneously to improve thermal conduction and dimensional stability.

Coupling agent-functionalized boron nitride (f-BN) and glycidyl methacrylate-grafted graphene (g-TrG) are simultaneously blended with polyimide (PI) to fabricate a flexible, electrically insulating and thermally conductive PI composite film. The silk-like g-TrG successfully fills in the gap between PI and f-BN to complete the thermal conduction network. In addition, the strong interaction between surface functional groups on f-BN and g-TrG contributes to the effective phonon transfer in the PI matrix. The thermal conductivity (TC) of the PI/f-BN composite films containing additional 1 wt % of g-TrG is at least doubled to the value of PI/f-BN and as high as 16 times to that of the pure PI. The hybrid film PI/f-BN-50/g-TrG-1 exhibits excellent flexibility, sufficient insulating property, the highest TC of 2.11 W/mK, and ultralow coefficient of thermal expansion of 11 ppm/K, which are perfect conditions for future flexible substrate materials requiring efficient heat dissipation.

Movie dialogues as discourse data in the study of forecasting mechanisms in the delivery of medical bad news.

Understanding the communication skills for delivering bad news, an important daily task for medical professionals, presents a challenge for most researchers due to methodological and ethical dilemmas. Movie dialogues, in which difficult communication of life-and-death issues are fundamental ingredients in creating dramatic effects, are often adopted in medical education and are thus potential data for study. By applying the concept of forecasting mechanism' in bad news delivery (Schegloff 1988; Maynard 2003), this study examines bad news delivery events depicted in three movie clips. My analysis demonstrates that (1) forecasting, as a 'macro conversation mechanism', is observed in both natural and artificial discourses; (2) two subtypes of forecasting are identifiable in movie dialogues:forecasting that directs the interaction to a 'recipient-leading-the-telling' pattern, and forecasting that constructs the delivery event as one with shared agency; and (3) the two subtypes may facilitate the deliverer's task by minimizing conflicting perspectives with the recipient, ensuring the recipient's orientation to the bad news, and freeing the deliverer from the pressure of being blamed. These findings indicate the possibility of applying movie clips in discourse research and medical education in regard to conversational strategies for difficult communication.

Learning to listen: effects of using conversational transcripts to help medical students improve their use of open questions in soliciting patient problems.

OBJECTIVE: This study reports effects of a 'bottom-up' pedagogy using doctor-patient conversation transcripts to improve medical students' use of open questions in soliciting patient problems. METHODS: We implemented an innovative approach involving students reviewing transcripts of medical interviews, skills practice using role-play and standardized patients (SPs), and reflection on these practices. We analyzed three open question categories (general, biomedical, and psychosocial) used by 27 Taiwanese medical students from two SP interviews, conducted before and after training. RESULTS: Across the full encounter, use of general and psychosocial open questions increased significantly after training (from 27 to 92 general questions and 15 to 33 psychosocial questions). The high rates of narrowly focused opening questions (52% of initial position questions, 74% of second position questions, and 85% of third position questions) prior to training were reduced to 11%, 15%, and 15% respectively after training. Students also shifted from a micro (narrow) to a macro (broad) pattern of questioning. CONCLUSION: The 'bottom-up' approach facilitated by using conversation transcripts is effective in improving communication skills. PRACTICE IMPLICATIONS: By carefully reviewing transcripts of their own performance as part of an overall communication training package, beginning medical students can become more patient-centered in soliciting patient problems.

Who gets to talk? An alternative framework evaluating companion effects in geriatric triads.

Most studies evaluating companion effects on medical triadic interaction focus on the doctors' part, e.g., how the companion's presence diverts doctors' attention away from the patient. In contrast to this mainstream approach, the current research proposes an alternative framework by focusing on the patient parties--especially on how companion participation reshapes the discourse sequences where patient parties provide information, and how it affects patient full turns and priority in providing complete first-hand information to doctors. By examining fifteen geriatric triadic conversations collected in a teaching hospital in southern Taiwan, this proposed framework concludes that in the companion's presence, the information providing sequences are restructured into eight patterns, among which sole information provider is preferred to joint providers. Furthermore, the more companions participate in providing information, the less patients by themselves volunteer information or respond to doctors' questions prior to companions' verbal involvement. A more striking companion effect shows that even in the triads with a low-participation companion, whenever the companion does participate, the patient rarely has a full turn or priority to complete an information unit. The patient's turns are either taken, are simultaneous with, or cut-off by the companion's participation.

Opening stages in triadic medical encounters in Taiwan.

Opening stages in medical interviews are important because good doctor-patient rapport facilitates the doctor's tasks in later stages, especially in triadic first-visit interviews where doctors are not acquaintances of patients and companions. Given its importance, the research examines opening stages in the Taiwanese context from two perspectives: discourse components of opening stages and discourse mechanisms of presenting non-acquaintances' identities, especially the companions' identities. By examining 30 geriatric triadic encounters collected in a teaching hospital in southern Taiwan, this research concludes that opening-stage interaction patterns in Taiwanese medical interviews differ from Western patterns in the following ways. Under time pressure, Taiwanese doctors tend to open the interview in a fast pattern that hardly allows verbal participation from the patients. The common practice of presenting non-acquaintances' identities in Western conversation openings is rarely observed in the Taiwanese context. As a result, contrary to the professional norms, most companions' identities are not clarified until they talk in the later stages, such as the pedigree stage, which is the most natural context for revealing their identities. This seeming violation of professional norms, however, can be explained by traditional Chinese interaction norms, and can be remedied by following another traditional norm-using a situational greeting. Further recommendations for Taiwanese medical professionals are also proposed to balance these potentially conflicting needs.