Increasing Chemical Diversity of B N Anthracene Derivatives by Introducing Continuous Multiple Boron-Nitrogen Units.

Increasing the chemical diversity of organic semiconductors is essential to develop efficient electronic devices. In particular, the replacement of carbon-carbon (C-C) bonds with isoelectronic boron-nitrogen (B-N) bonds allows precise modulation of the electronic properties of semiconductors without significant structural changes. Although some researchers have reported the preparation of B N anthracene derivatives with two B-N bonds, no compounds with continuous multiple BN units have been prepared yet.

Kinetic-Controlled Crystallization of α-FAPbI Inducing Preferred Crystallographic Orientation Enhances Photovoltaic Performance.

Crystallization kinetic controls the crystallographic orientation, inducing anisotropic properties of the materials. As a result, preferential orientation with advanced optoelectronic properties can enhance the photovoltaic devices' performance. Although incorporation of additives is one of the most studied methods to stabilize the photoactive α-phase of formamidinium lead tri-iodide (α-FAPbI ), no studies focus on how the additives affect the crystallization kinetics.

Hole-Transporting Vanadium-Containing Oxide (VO) Interlayers Enhance Stability of α-FAPbI-Based Perovskite Solar Cells (∼23%).

Perovskite solar cells (PSCs) have attracted tremendous interest due to their outstanding intrinsic photovoltaic properties, such as absorption coefficients, exciton binding energies, and long carrier lifetimes. Although the power conversion efficiency (PCE) of PSCs is close to the Si solar cells' PCE, device stability remains a challenge. In particular, the device stability is more critical in n-i-p normal structured PSCs, which show a higher efficiency than p-i-n inverted ones, simply because of the much lower stability of 2,2',7,7'-tetrakis[,-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spi).

Influence of Chewing Ability on Elderly Adults' Cognitive Functioning: The Mediating Effects of the Ability to Perform Daily Life Activities and Nutritional Status.

Chewing ability is also related to activities of daily living (ADLs) and nutritional status; however, these associations have not been firmly established. We examined chewing ability as a predictor variable and explored its relationship with cognitive functioning as mediated by ADLs and nutritional status data were collected by face-to-face interviews. Patients were receiving home healthcare service in Mun-gyeong city, Gyung-buk, Korea.

Unusual Hole Transfer Dynamics of the NiO Layer in Methylammonium Lead Tri-iodide Absorber Solar Cells.

Nickel oxides (NiO) as hole transport layers (HTLs) in inverted-type perovskite solar cells (PSCs) have been widely studied mainly because of their high stability under illumination. Increases in the power conversion efficiency (PCE) with NiO HTLs have been presented in numerous reports, although the photoluminescence (PL) quenching behavior does not coincide with the PCE increase. The dynamics of the charge carrier transport between the NiO HTLs and the organic-inorganic halide perovskite absorbers is not clearly understood yet and quite unusual, in contrast to organic/polymerics HTLs.

Atomic layer deposition for efficient and stable perovskite solar cells.

Organic-inorganic hybrid metal halides are now the most attractive photovoltaic absorber materials, typically, methylammonium lead triiodides (MAPbI3). These unique semiconducting materials as absorbers demonstrate a remarkably improved power conversion efficiency of over 20% and now with a certified efficiency of 23.3%.

Atomic layer deposition of a SnO electron-transporting layer for planar perovskite solar cells with a power conversion efficiency of 18.3.

High-efficiency planar type perovskite solar cells were fabricated by atomic layer deposition (ALD) of SnO2 and subsequent annealing at 180 °C. As-dep. SnO2 layers prepared by post-annealing at 180 and 300 °C, respectively, were used as electron transporting layers (ETLs).

p-Type CuCrO particulate films as the hole transporting layer for CHNHPbI perovskite solar cells.

CuCrO with a crystal structure of delafossite is a promising material as a transparent conducting oxide. It shows unique properties, for example, wide band gap, good chemical stability, and p-type carrier transporting character. The oxide layers with delafossite structure have been suggested as hole transporting materials for organic-inorganic CHNHPbI perovskite solar cells.

Perovskite Solar Cells with Inorganic Electron- and Hole-Transport Layers Exhibiting Long-Term (≈500 h) Stability at 85 °C under Continuous 1 Sun Illumination in Ambient Air.

Despite the high power conversion efficiency (PCE) of perovskite solar cells (PSCs), poor long-term stability is one of the main obstacles preventing their commercialization. Several approaches to enhance the stability of PSCs have been proposed. However, an accelerating stability test of PSCs at high temperature under the operating conditions in ambient air remains still to be demonstrated.

Factors affecting use of word-of-mouth by dental patients.

Objectives: Word-of-mouth (WOM) refers to communication among consumers, which greatly influences the marketing strategies of dental clinics. This study aimed to explore factors that affect use of WOM by dental patients and to analyse their pathways.

Methods: The participants were 520 outpatients from four private dental clinics.

Dental amalgam exposure can elevate urinary mercury concentrations in children.

Objectives: Owing to its cost-effectiveness and operative convenience, dental amalgam remains in use as a restorative material for tooth caries in children in many countries. The aim of this study was to evaluate the relationship between dental amalgam exposure and urinary mercury (U-Hg) concentrations in children.

Methods: In this longitudinal study, 463, 367 and 348 children, 8-11 years of age, were evaluated at baseline, and at the first and second follow-up visits, respectively.

Efficacy of various cleaning solutions on saliva-contaminated zirconia for improved resin bonding.

Purpose: This study aimed to investigate the efficacy of cleaning solutions on saliva-contaminated zirconia in comparison to air-abrasion in terms of resin bonding.

Materials And Methods: For saliva-contaminated airabraded zirconia, seven cleaning methods)-no contamination (NC), water-spray rinsing (WS), additional airabrasion (AA), and cleaning with four solutions (Ivoclean [IC]; 1.0 wt% sodium dodecyl sulfate [SDS], 1.

Burnout and its related factors in Korean dentists.

Objectives: Dentistry has been identified as one of the most stressful work environments. Knowledge of modifiable work-environment factors related to job stress could lead to a strategy and policy to provide a better work environment for dentists. The aims of this study were to examine the degree and distribution of burnout and to determine the factors associated with burnout subscale of Korean dentists.

Bone healing with oxytocin-loaded microporous β-TCP bone substitute in ectopic bone formation model and critical-sized osseous defect of rat.

Aim: This study investigated the efficacy of the hypothalamic nonapeptide oxytocin (OT) by direct delivery to local defects using a microporous β-tricalcium phosphate (TCP) as the carrier for the future applications as a method to achieve predictable bone regeneration of large osseous defects requiring sinus bone graft and guided bone regeneration procedures for implant placement.

Material And Methods: Both the ectopic and new bone formation induced by the OT-loaded microporous β-TCP powder was histomorphometrically compared with unloaded β-TCP in a subcutaneous ectopic bone formation model and calvarial critical-sized defects (CSDs) in 45 rats.

Results: The OT-loaded β-TCP clearly enhanced ectopic bone formation compared with the unloaded control group.

Osseointegration of commercial microstructured titanium implants incorporating magnesium: a histomorphometric study in rabbit cancellous bone.

Objective: Recent studies have suggested that magnesium (Mg) ions exert a beneficial effect on implant osseointegration. This study assessed the osseointegration of nanoporous titanium (Ti) surface incorporating the Mg produced by hydrothermal treatment in rabbit cancellous bone to determine whether this surface would further enhance bone healing of moderately rough-surfaced implants in cancellous bone, and compared the result with commercially available micro-arc oxidized Mg-incorporated implants.

Material And Methods: The Mg-incorporated Ti surfaces (RBM/Mg) were obtained by hydrothermal treatment using an alkaline Mg-containing solution on grit-blasted moderately rough (RBM) implants.

The effect of intensive oral hygiene care on gingivitis and periodontal destruction in type 2 diabetic patients.

Purpose: This study aimed to investigate the effects of oral hygiene care by oral professionals on periodontal health in type 2 diabetes mellitus patients.

Materials And Methods: Diabetic participants were recruited at a university hospital and matched at a 1:1 ratio by age and gender, and randomly allocated into intervention (40 people) and control groups (35 people). Tooth brushing instruction, oral health education, and supra-gingival scaling were implemented in all patients at baseline.

Morphological changes in Streptococcus mutans after chewing gum containing xylitol for twelve months.

Few studies have been conducted to evaluate the effect of xylitol on the virulence and morphology of Streptococcus mutans (S. mutans). This study was conducted to evaluate changes in the morphology and virulence of S.

Density of the alveolar and basal bones of the maxilla and the mandible.

Introduction: The purpose of this investigation was to quantitatively evaluate density of the alveolar and basal bones of the maxilla and the mandible.

Methods: Sixty-three sets of computed tomographic (CT) images were selected, and bone density was measured with V-Works imaging software (Cybermed, Seoul, Korea). The sample consisted of 23 men (ages, 29 +/- 10.

Xenon light has effectiveness on the detection of incipient carious lesions on bovine enamel in vitro.

Objective: Filtered 325-nm xenon light was used to test its effectiveness in the detection of incipient carious lesions on bovine enamel by measuring the fluorescence spectrum.

Background Data: The combination of early detection with new interventional methodology and caries management will be the preferred dental practice in the future.

Methods: Specimens of bovine tooth enamel were embedded in resin, polished, exposed to a lactate carbopol buffer system for 71 hours, and randomly divided into one control and three test groups of 10 specimens each, with Vickers hardness number (VHN) stratification.

Factors related to job satisfaction among South Korean dentists.

Objectives: The purposes of this study were to investigate the level and distribution of job satisfaction and to explore work environment factors associated with job satisfaction of South Korean dentists.

Methods: A stratified systematic random sample of 1029 dentists was selected from the 10 357 registered dentists in the Korean Dental Association. They were surveyed via a self-administered mail questionnaire.

Factors affecting the clinical success of screw implants used as orthodontic anchorage.

Introduction: The purposes of this study were to examine the success rates and find factors affecting the clinical success of screw implants used as orthodontic anchorage.

Methods: Eighty-seven consecutive patients (35 male, 52 female; mean age, 15.5 years) with a total of 227 screw implants of 4 types were examined.