Mist chemical vapor deposition of crystalline MoS2atomic layer films using sequential mist supply mode and its application in field-effect transistors.

Molybdenum disulfide (MoS2) mono/bilayer have been systematically investigated using atmospheric-pressure mist chemical vapor deposition (mist CVD) from (NH4)2MoS4dissolved in N-methyl-2-pyrrolidone as a precursor. Film deposition was performed by alternating MoS2mist storage within a closed chamber and mist exhaust, i.e. sequential mist supply mode at different furnace temperatures, storage times of precursor, and repetition cycles of mist supply on thermally grown SiO2(th-SiO2) and mist-CVD grown Al1-xTixOy(ATO) layers coated on p+-Si substrates. The average size of the MoS2flake and their number of stack layers could be controlled by tuning the deposition parameters combined with substrate pretreatment. Field-effect transistors with MoS2atomic mono/bilayer as a channel layer exhibited mobility up to 31-40 (43-55) cm2V-1s-1with a threshold voltage of -1.6 (-0.5) V, subthreshold slope of 0.8 (0.11) V dec.-1, and on/off ratio of 3.2 × 104(3.6 × 105) onth-SiO2(ATO) layers as gate dielectric layers without mechanical exfoliation. These findings imply that mist CVD is available for the synthesis of metal transition metal dichalcogenide and metal oxide layers as channel and gate dielectric layers, respectively.

What impact does postgraduate clinical training have on empathy among Japanese trainee dentists?

BACKGROUND: Enhancing empathy in healthcare education is a critical component in the development of a relationship between healthcare professionals and patients that would ensure better patient care; improved patient satisfaction, adherence to treatment, patients' medication self-efficacy, improved treatment outcomes, and reduced patient anxiety. Unfortunately, however, the decline of empathy among students has been frequently reported. It is especially common when the curriculum transitions to a clinical setting. However, some studies have questioned the significance and frequency of this decline. Thus, the purpose of this study was to determine the impact of postgraduate clinical training on dental trainees' empathy from cognitive, behavioral, and patients' perspective. METHODS: This study included 64 trainee dentists at Okayama University Hospital and 13 simulated patients (SPs). The trainee dentists carried out initial medical interviews with SPs twice, at the beginning and the end of their clinical training. The trainees completed the Japanese version of the Jefferson Scale of Empathy for health professionals just before each medical interview. The SPs evaluated the trainees' communication using an assessment questionnaire immediately after the medical interviews. The videotaped dialogue from the medical interviews was analyzed using the Roter Interaction Analysis System. RESULTS: No significant difference was found in the self-reported empathy score of trainees at the beginning and the end of the clinical training (107.73 [range, 85-134] vs. 108.34 [range, 69-138]; p = 0.643). Considering the results according to gender, male scored 104.06 (range, 88-118) vs. 101.06 (range, 71-122; p = 0.283) and female 109.17 (range, 85-134) vs. 111.20 (range, 69-138; p = 0.170). Similarly, there was no difference in the SPs' evaluation of trainees' communication (10.73 vs. 10.38, p = 0.434). Communication behavior in the emotional responsiveness category for trainees in the beginning was significantly higher than that at the end (2.47 vs. 1.14, p = 0.000). CONCLUSIONS: Overall, a one-year postgraduate dental training program neither reduced nor increased trainee dentists' empathy levels. Providing regular education support in this area may help trainees foster their empathy.

Chemical activity of oxygen atoms in the magnetron sputter-deposited ZnO films during film growth.

The role of oxygen atoms in the growth of magnetron sputter-deposited ZnO films was studied in a deposition and post-deposition study in which the deposition of a several-nanometer-thick ZnO layer altered with an exposure to an O2/Ar mixed plasma, i.e., a layer-by-layer (LbL) technique. The film crystallization was promoted by suppressing the oxygen vacancy and interstitial defects by adjusting the exposure conditions of the O2/Ar plasma. These findings suggest that the chemical potential of the oxygen atom influences the film crystallization and the electronic state. The diffusion and effusion of oxygen atoms at the growing surface have an effect similar to that of thermal annealing, promoted film crystallization and the creation and the annihilation of oxygen- and zinc-related defects. The role of oxygen atoms reaching the growing film surface is discussed in terms of chemical annealing and a possible oxygen diffusion mechanism is proposed.

Real-time ellipsometric characterization of the initial growth stage of poly(3,4-ethylene dioxythiophene): poly(styrene sulfonic acid) films by electrospray deposition.

Kinetic spectroscopic ellipsometry have been used to study the initial growth stage of poly(3,4-polyethylene dioxythiophene):poly(styrenesulfonic acid)(PEDOT:PSS) films by the electrospray deposition (ESD) method. The real-time spectra analysis revealed that the surface overlayer decreased in thickness once the first bulk layer monolayer was formed, indicating a smoothening effect as the nucleation-related microstructure coalesced into the bulk layer. Once the coalescence was completed and the nucleation-induced surface roughness layer was stabilized, the underlying bulk layer increased linearly with time. These results originate from the degrees of the evaporation of solvent material during the transferring the precursors to the surface and/or of the diffusion of deposition precursors after sticking at the growing surface.

Surface modification of poly(3,4-ethylene dioxthiophene):poly(styrene sulfonic acid) (PEDOT:PSS) films by atmospheric-pressure argon plasma for organic thin-film solar cells.

Highly-conductive poly(3,4-ethylene dioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS) films obtained by the addition of dimethylsulfoxide (DMSO) and the argon plasma exposure were used as a transparent conductive anode (TCA) for copper-phthalocyanine (CuPc)/C60 organic thin-film solar cells (OSCs). The CuPc/C60 OSCs on as-grown DMSO added PEDOT:PSS layer showed a power efficiency of 0.6%, whereas it was improved markedly to 1.34% after the atmospheric-pressure argon plasma exposure, which was comparable to that formed on indium-tin-oxide layer. Effects of the DMSO addition and the argon plasma exposure in the spin-coated PEDOT:PSS films is demonstrated in terms of the in-depth characterization of optical and electrical properties.

Thiocyanate Containing Two-Dimensional Cesium Lead Iodide Perovskite, Cs2PbI2(SCN)2: Characterization, Photovoltaic Application, and Degradation Mechanism.

We explored thiocyanate (SCN)-based two-dimensional (2D) organometal lead halide perovskite families toward photovoltaic applications. Using an SCN axial ligand and various cation species, we examined AA'PbI2(SCN)2-type 2D perovskite by replacing the cation species (AA') between methylammonium (MA), formamidinium (FA), and cesium. Among various cation compositions, only all-inorganic cesium-based SCN perovskite, Cs2PbI2(SCN)2, film showed high thermal stability compared to known 2D perovskites. Perovskite solar cells (PSCs) using the Cs2PbI2(SCN)2 absorber yielded approximately 2% conversion efficiency on the mesoscopic device. Relatively low efficiency is attributed, in addition to optical properties (large band gap (2.05 eV) and exciton absorption), to the orientation of perovskite layer parallel to the layered structure, preventing carrier extraction from the light-absorber perovskite. In device stability, the Cs-based 2D perovskite was stable against oxygen (oxidation), whereas it was found to be unstable against humidity. X-ray diffraction and X-ray photoelectron spectroscopy measurements showed that, unlike long alkylammonium-based 2D perovskite families such as BA2PbI4 (BA = butylammonium), the Cs-based 2D perovskite can undergo hydrolysis due to the hydrophilic Cs cations.

Relationship of trainee dentists' self-reported empathy and communication behaviors with simulated patients' assessment in medical interviews.

OBJECTIVES: We aimed to clarify the communication behaviors between trainee dentists and simulated patients (SPs), to examine how the level of trainee dentists' self-reported empathy influences assessment by SPs in medical interviews. MATERIALS AND METHODS: The study involved 100 trainee dentists at Okayama University Hospital and eight SPs. The trainee dentists conducted initial interviews with the SPs after completing the Japanese version of the Jefferson Scale of Empathy (JSE). All interviews were recorded and analyzed using the Roter Interaction Analysis System (RIAS). The SPs assessed the trainees' communication immediately after each interview. The trainee dentists were classified into two groups (more positive and less positive) according to SP assessment scores. RESULTS: Compared with less-positive trainees, the more-positive trainees scored higher in the RIAS category of emotional expression and lower in the medical data gathering category. There was no difference in dental data gathering between the two groups. SP ratings for more-positive trainees were higher for use of positive talk and emotional expression and lower for giving medical information and dental information. Trainees with more positive ratings from SPs had significantly higher JSE total scores. CONCLUSION: The results of this study suggest that responding to the emotions of patients is an important behavior in dentist-patient communication, according to SPs' positive assessment in medical interviews. Further, SPs' assessment of trainees' communication was related to trainees' self-reported empathy, which indicates that an empathic attitude among dentists is a significant determinant of patient satisfaction.

Nafion-Modified PEDOT:PSS as a Transparent Hole-Transporting Layer for High-Performance Crystalline-Si/Organic Heterojunction Solar Cells with Improved Light Soaking Stability.

We demonstrate the chemistry of amphiphilic perfluorosulfonic copolymer Nafion-coated conductive poly(3,4-ethyelenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and its effect on the photovoltaic performance of PEDOT:PSS/crystalline Si (c-Si) heterojunction solar cells. The highly hydrophilic sulfonate group of insulating, chemically stable Nafion interacts with PSS in PEDOT:PSS, which reduce the Coulombic interaction between PEDOT and PSS. The highly hydrophobic fluorocarbon backbone of Nafion favorably interacts with hydrophobic PEDOT of PEDOT:PSS. These factors give rise to the extension of π-conjugation of PEDOT chains. Silver paste used as a top grid electrode diffused into the Nafion layer and contacted with underneath Nafion-modified PEDOT:PSS layer. As a consequent, solution-processed Nafion-coated PEDOT:PSS/c-Si heterojunction solar cells exhibited a higher power conversion efficiency of 14.0% with better stability for light soaking rather than that of the pristine PEDOT:PSS/c-Si device by adjusting the layer thickness of Nafion. These findings originate from the chemical stability of hydrophobic fluorocarbon backbone of Nafion, diffusivity of silver paste into Nafion and contact with PEDOT:PSS, and Nafion as an antireflection layer.

Ultra-structural evaluation of an anodic oxidated titanium dental implant.

Anodic oxidation is used for the surface treatment of commercial implants to improve their functional properties for clinical success. Here we conducted ultrastructural and chemical investigations into the micro- and nanostructure of the anodic oxide film of a titanium implant. The anodic oxidized layer of a Ti6Al4V alloy implant was examined ultrastructurally by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). They were also analyzed using energy dispersive X-ray spectrometry (EDS) and X-ray photoelectron spectroscopy (XPS). The TEM revealed that the oxide layer of the Ti6Al4V implant prepared through anodic oxidation was separated into two layers. Al and V were not present on the top surface of the anodic oxide. This can be attributed to the biocompatibility of the anodic oxidized Ti6Al4V alloy implant, because the release of harmful metal ions such as Al and V can be suppressed by the biocompatibility.

The effect of diabetes mellitus on the expression of Argyrophilic nucleolar organizer regions (AgNORs) in mucosal epithelium under experimental denture bases in rats.

BACKGROUND: Expression of argyrophilic nucleolar organizer regions (AgNOR) was counted on mucosal epithelium to detect whether the AgNOR count (the number of AgNOR per nucleus) is, for 20 weeks, affected by streptozotocin-induced diabetes mellitus. METHODS: Diabetic rats were applied non-denture wearing, non-pressure contact, continuous pressure (0.5, 1.5 or 3.4 kPa) and intermittent pressure (10.5, 33.0 or 81.7 kPa), respectively. RESULTS: In the non-denture wearing or the non-pressure contact group, AgNOR count was almost constant (ranging 1.86-1.92) without significant difference. Under continuous pressure, AgNOR count significantly decreased at earlier stage and finally recovered to the non-pressure contact group. A similar effect of continuous pressure appeared to manifest itself in intermittent pressure, but to a greater degree. Consequently, AgNOR count under intermittent pressure showed no recovery at 20-week stage. CONCLUSION: : Diabetes mellitus exerted, by itself, no influence on the cellular proliferative activity under continuous pressure, whereas the activity deteriorated under intermittent pressure.