Diversity of short-term DC outcomes in bulk-fill RBCs subjected to a 3 s high-irradiance protocol.

OBJECTIVES: To determine the short-term (5 min) initial effects of a high-irradiance light-curing (LC) protocol on light transmission (LT%), radiant exposure (RE) and degree of conversion (DC%) of different bulk-fill resin-based composites (RBCs). MATERIALS AND METHODS: Six bulk-fill composites with different viscosities were investigated: OBF (One Bulk Fill, 3 M), EB (Estelite bulkfill,Tokuyama), PFill, PFlow, ECeram and EFlow (PowerFill, Poweflow, Tetric EvoCeram bulkfill, Tetric Evoflow bulkfill, Ivoclar), subjected to different LC protocols: one ultra-high-intensity (3 W/cm2 -3 s via PowerCure LCU) and two conventional (1.2 W/cm2 -10 s and 20 s via PowerCure and Elipar S10 LCUs). Specimens (n = 5) were polymerized within their molds (ϕ5 mm × 4 mm depth) to determine LT% and RE at 4 mm using a MARC-LC spectrometer. For real-time DC% measurements by FTIR, similar molds were utilized. Data were analyzed by one-way ANOVA and Tukey post-hoc tests at 5 % significance. RESULTS: Regardless of the applied LC protocols, OBF and low-viscosity RBCs (EB, PFlow and EFlow) had the lowest and highest LT%, RE, DC% and RPmax, respectively. RE results of all RBCs were in the same sequence: Elipar-20 s > PCure-10 s > PCure-3 s. DC% of PFill and PFlow displayed no significant difference between the applied LC protocols (p > 0.05). The polymerization kinetic in all materials was well described by an exponential sum function (r2 varied between 0.85 and 0.98), showing a faster polymerization with the PCure-3 s protocol. SIGNIFICANCE: The measurement of LT% and DC% at 5 min gave an insight into the developing polymerization process. The initial response of these bulk-fill composite to a high-irradiation protocol varied depending on their composition and viscosity, being faster for low viscosity materials. Nevertheless, even though multiple resin composites are designed to be efficient during photopolymerization, care should be taken when selecting materials/curing protocol.

Sufficiency of curing in high-viscosity bulk-fill resin composites with enhanced opacity.

OBJECTIVES: The study aims analyzing if improved opacity in modern high-viscosity bulk-fill resin composites (BF-RBC) contradicts with the sufficiency of curing and to assess material's tolerance to less ideal curing conditions. MATERIALS AND METHODS: Simulated large cavities (10 × 6) mm were filled in one increment with three BF-RBCs (Filtek One, FO; Tetric Evo Ceram Bulk Fill, TEC-BF; SonicFill2, SF2). One central and two peripheral (4 mm apart from the center) micromechanical property line-profiles (HV, Vickers hardness; YHU, indentation modulus) were measured in 0.2-mm steps at 24 h post-polymerization (n = 6). Depth of cure (DOC) was calculated from the HV variation in depth. A scratch test (DOCscratch test) estimated the tolerance in polymerization when simulating clinically relevant curing conditions (exposure distance up to 7 mm; centered and with a 3-mm offset placement of the LCU). Irradiance and spectral distribution of the used light curing unit (LCU) were assessed at various curing conditions. RESULTS: DOC varied among 3.6 mm (SF2, peripheral) and 5.7 mm (FO, central). The BF-RBC influences DOC stronger (p < 0.001, ηP2 = 0.616) than the width (p < 0.001, ηP2 = 0.398). Significant lower DOC (t test) was measured peripheral compared to center in all materials. YHU was more sensitive to the varied parameters as HV. DOCscratch test varied among 2.4 mm (SF2, 3-mm offset, exposure distance 7 mm) and 3.9 mm (FO, center, 0 mm). CONCLUSIONS: Whether opacity competes with DOC is material dependent. BF-RBCs tolerate small variations in LCU's centricity better than variations in exposure distance. CLINICAL RELEVANCE: The upper incremental thickness threshold of 4 or 5 mm was not reached in all BF-RBCs under simulated clinically relevant curing conditions.

Inhibition of Staphylococcus aureus biofilm by a copper-bearing 317L-Cu stainless steel and its corrosion resistance.

The present study investigated the antibacterial performance, corrosion resistance and surface properties of antibacterial austenitic 317L-Cu stainless steel (317L-Cu SS). After 4.5wt% copper was added to 317L stainless steel (317L SS), the new alloy underwent solid solution and aging heat treatment. Fluorescent staining using 4',6-diamidino-2-phenylindole (DAPI) revealed that the 317L-Cu SS showed strong antibacterial efficacy, achieving a 99% inhibition rate of sessile Staphylococcus aureus cells after 5days. The corrosion data obtained by potentiodynamic polarization curves indicated that in comparison with 317L SS, the pitting potential and corrosion current density of 317L-Cu slightly decreased due to the addition of Cu. The 317L-Cu SS exhibited no cytotoxicity against zebrafish (Danio rerio) embryos. The experimental results in this study demonstrated that the new alloy has potential applications in medical and daily uses.

The characteristics of the suicide attempter according to the onset time of the suicidal ideation.

OBJECTIVE: To determine the timing of development of suicidal ideation and factors associated therewith in suicide attempters who required psychiatric emergency treatment. METHODS: Of a total of 2818 suicide attempters in Japan who presented to the primary or secondary emergency department of Iwate Medical University Hospital (hereinafter, referred to as our hospital) or Iwate Prefecture Advanced Emergency and Critical Care Center (hereinafter, referred to as the emergency center), an affiliated institution to our hospital, during the 12-year period from April 1, 2002-March 31, 2014, 2274 patients for whom the timing of development of suicidal ideation was identified were included in the study. The study subjects were classified into three groups according to the timing of development of suicide ideation: the "same-day" group, those who developed suicidal ideation and attempted suicide on the same day; the "short-term" group, those who developed suicidal ideation 2-7 days before attempting suicide; and the "long-term" group, those who developed suicidal ideation more than 7 days before attempting suicide. Factors associated with the development of suicidal ideation in each group were analyzed by a multiple logistic regression analysis with background factors, the diagnosis according to the ICD and the situations before and after the suicide attempt as explanatory variables. RESULTS: The same-day group was characterized by a high female ratio, high global functioning, low stress level, non-depressed status and a lack of seeking consultation. In contrast, the long-term group was characterized by low global functioning and a high stress level, suggesting that these patients exhibit consultation behavior, but have not received psychiatric services. In the short-term group, only male gender was identified as a significant factor. DISCUSSION: For those patients who developed suicidal ideation and attempted suicide on the same day, treatment strategies focusing on the acquisition of coping skills and stress management are recommended. For those with suicidal ideation lasting for more than a week or recurrent ideation, early detection and subsequent early treatment of such ideation are essential. In intermediate cases, treatment strategies that make the full use of mental health management in the workplace and gate-keeping are likely to be effective.

Multicenter ICU Surveillance Study for Nosocomial Infection in Korea / 병원감염관리

Purpose: The purpose of this study is to determine the risk adjusted nosocomial infection (NI) rate and distribution of Nls and their causative pathogens in adult lCU. Methods: Prospective surveillance was performed at 12 lCU's of 5 acute care hospitals in Seoul and Kyonggi Do during a 3-months period from May to July 2002. The case finding was done by direct reviews of medical charts regularly for all patients by ICPs using CDC definitions. Results: Total NI rate was 10.18/1,000 patient-days in Medical-surgical ICU (MSICU) and 12.35/1,000 patient-days in Neurosurgucal ICU(NCI). Risk adjusted infection rate was 3.44 in indwelling catheter associated UTI 2.12 in central line associated BSI. 3.51/1,000 device-days in ventilator associated pneumonia in MSICU. There were 3.72, 2.26, 6.06/1,000 device-days in NCU. The infection rate by leu type showed no significant difference. The distribution of Nls were PNEU (28.99%). UTI (28.99%), BSI (18,84%), SSI(4.35%) in MSICU, and UTI(48.0%), PNEU(24.0%), BSI (14.0%), SSI(6.I) in NCU. The most commonly isolated organisms were Candida spp (38.6%), Enterococcus spp. (13.4%) in UTI, Staphylococcus aureus(36.2%), p. aeruginosa(18.8%) in PNEU and Coagulase negative staphylococcus(44.1%). S. aureus (14.7%) in BSL, S. aureus (19.8%) was the most common organism from overall nosocomial infections in the ICU, and 96.3% of S. aureus were MRSA. Conclusion: Distribution of site-specific nosocomial infection and isolated organisms were similar to the results of KOSNIC (Korea society for nosocomial infection control) surveillance in 1996. However, the total infection rate and a risk adjusted infection rate at MSJCU is lower than 1996's. This decrease is considered to be a result of efforts to prevention and control nosocomial infections.

A Study on Stress and Personality Characteristics of the Central Serous Chorioretinopathy Patients

To investigate the relationship between psychological behavior and the development of central serous chorioretinopathy, we performed a study on stress and personality characteristics on 39 central serous chorioretinopathy patients and 38 healthy subjects as a control group. We used Life Change Inventory(MMPI) for personality characteristics. As a result, the mean stress scale in the patients group was significantly higher than in the normal control group(p<0.05) and the mean T-xcore of three neurotic scales such as hypochondriasis, depression and hysteria in the patients group were significantly higher than in the normal control group(p=0.029, 0.004, 0.012).