Erbium-doped-fiber-based broad visible range frequency comb with a 30 GHz mode spacing for astronomical applications

Optical frequency combs have the potential to improve the precision of the radial velocity measurement of celestial bodies, leading to breakthroughs in such fields as exoplanet exploration. For these purposes, the comb must have a broad spectral coverage in the visible wavelength region, a wide mode spacing that can be resolved with a high dispersion spectrograph, and sufficient robustness to operate for long periods even in remote locations. We have realized a comb system with a 30 GHz mode spacing, 62 % available wavelength coverage in the visible region, and 40 dB spectral contrast by combining a robust erbium-doped-fiber-based femtosecond laser, mode filtering with newly designed optical cavities, and broadband-visible-range comb generation using a chirped periodically-poled LiNbO3 ridge waveguide. The system durability and reliability are also promising because of the stable spectrum, which is due to the use of almost all polarization-maintaining fiber optics, moderate optical power, and good frequency repeatability obtained with a wavelength-stabilized laser.Comment: 19 pages, 5 figure

Analysis of subgingival microbiota in monozygotic twins with different severity and progression risk of periodontitis

The study aims to reveal the composition of subgingival bacteria in monozygotic twins with discordant in severity and progression risk of periodontitis. Microbiome analysis indicated that most bacteria were heritable but differed in their abundance and immune response. The dysbiotic bacteria can be considered as risk markers for periodontitis progression

Effectiveness and safety of low-concentrated ozonized water for the reduction of contamination in dental unit water lines

Contamination of dental unit waterlines (DUWL) with heterotrophic bacteria can cause problems in immune compromised patients (aged, tumor and organ transplantation-patients). We focused on the use of low-concentrated ozonized water (OZW) as the biofilm formation restraint system for DUWL. Here, we examined the effects of low-concentrated OZW on the growth of bacteria and related biofilm formation and harmfulness to dental unit components (DUCs) in vitro. Objectives To evaluate the bactericidal effects of OZW on biofilms in DUWL and DUC in vitro. Methods Low-concentrated OZW (0.4 mg/L) was generated using an OZS-PTDX generator. Heterotrophic bacterial biofilms in old DUWL tubes and Candia albicans solution (control microbe) were treated with OZW for 1 h with gentle agitation before static culturing for 96 h in Reasoner's 2A liquid media. The control solutions were 0.1% cetylpyridinium chloride (CPC), chlorinated tap water (TW), and phosphate-buffered saline (PBS). Adenosine triphosphate (ATP) amounts of the microbes were measured and the biofilms of these microbes were observed using scanning electron microscopy (SEM). Moreover, surfaces of DUC soaked in OZW and TW were observed by SEM. Results The OZW reduced ATP levels in microbes to 50% compared to TW and PBS treatment, although CPC reduced it below detection limits. SEM observation revealed deformation of microbes cultured with OZW, whereas no changes were seen on DUC surfaces. Conclusions Low-concentrated OZW is bactericidal against heterotrophic bacteria biofilms and it is not harmful to DUC, suggesting that it might be useful in preventing DUWL contamination

Evaluation of the simulator with automatic irrigation control system designed for countermeasures of internal contamination in dental unit water lines

The prevention of nosocomial infections is an imperative task. The dental chair unit (DCU) is an indispensable device used in dental treatment. However, it is known that the dental unit water line (DUWL) can become contaminated with biofilm, consisting mainly of heterotrophic bacteria (HB). Recently, the International Organization for Standardization specified the methods for testing DUWL contamination management. On these grounds, a simulator reproducing DUWL was prepared to standardize the examination method of the DUWL contamination. Objectives To evaluate the reproducibility of the DUWL simulator, monitor the DUWL contamination states, and test the efficacy of a commercial decontaminant for DUWL. Methods The DUWL simulator was assembled by a DCU manufacturing company. The simulator's DUWL was filled with tap water (TW), and left for approximately one year. Neutral electrolyzed water (NEW) was used as a decontaminant for DUWL. Both TW and NEW were passed through DUWL in a timely manner simulating daily dental treatment. Water was sampled from the air turbine hand piece weekly for 4 weeks and used for HB culture. Contamination status was evaluated by measuring bacterial adenosine triphosphate release and by culturing on Reasoner's 2A medium. Results The DUWL released contaminated water had a bacterial count of over 6 × 104 cfu/mL. After passing NEW through DUWL for 1 week, the count drastically decreased to its basal level and remained steady for 4 weeks. However, TW showed no effect on DUWL decontamination throughout the examination periods. Conclusions The DUWL simulator could be useful to examine the efficacy of the decontaminant for DUWL and development of new methods in DUWL contamination management

Macroscopic tribological properties of thick concentrated polymer brush on rough steel under lubrication with ionic liquid

Concentrated polymer brush (CPB) is the polymer film with a structure that possesses greatly extended polymer chains densely grafted to substrate. CPB is known to swell in good solvents, which have high affinity for the polymer. Swollen CPB by a good solvent shows excellent micro-tribological properties such as super lubrication with the extremely low friction coefficient (μ~10-4). However, macro-tribological properties of CPB surface on steel have not been explored sufficiently. In this study, macroscopic tribological properties of a CPB on rough steel were evaluated using a block-on-ring type tribo-tester under lubrication with an ionic liquid. The CPB showed a significant friction reduction effect with the low friction coefficient of 0.005 on macroscale

BRCA2 Frameshift Mutation in de novo Small-Cell Neuroendocrine Carcinoma of the Prostate: A Case Report

A 66-year-old male was diagnosed with cT4N0M1b small-cell neuroendocrine carcinoma of the prostate. Four months after the administration of combined androgen blockade, multiple novel metastatic regions in the lung and liver and progression of bone metastasis were observed. The patient was referred to our hospital because of biochemical and radiographic progression after four cycles of docetaxel as a first-line therapy for castration-resistant prostate cancer. Transurethral resection of the prostate and hepatic biopsy revealed small-cell carcinoma with positive expression of neuroendocrine markers. The FoundationOne CDx next-generation sequencing test revealed several pathogenic variants, including BRCA2 (W1692fs*3), KEAP1 (R320W), and TP53 (C2385) mutation. After four cycles of chemotherapy with carboplatin plus etoposide (CE), the metastatic regions regressed markedly. The prostate-specific antigen (PSA) and neuron-specific enolase (NSE) level decreased by 96.9% and 91.6%, respectively. However, 2 months after the completion of four cycles of CE, elevation of tumor marker levels, and re-growth of the metastatic regions were observed. Although olaparib, a poly (ADP-ribose) polymerase inhibitor (PARPi), achieved a 45.2% decrease in NSE, the patient rejected to continue therapy because of G2 adverse events. After receiving an additional two cycles of CE and one cycle of cabazitaxel, the patient died because of cancer progression 24 months after the initial treatment for prostate cancer. Here, we present a case of BRCA2-altered small-cell neuroendocrine prostate cancer treated with both platinum-containing chemotherapy and PARPi. Both therapies achieved an initial response; however, durable responses were not obtained. Additional discussion regarding the optimal treatment strategy for BRCA-altered small-cell/neuroendocrine prostate cancer is required

The relationships between internal working models of caregiving : Care for child and care for partner

Caregiving behavior, the important element in dyadic relationship, occurred by activation of caregiving behavioral system. Repeat experiences of such activation constructs a type of mental representation, as a terminology in attachment theory, internal working model (IWM). It is said that such IWMs of caregiving are constructed for each recipient separately. The purpose of this study is to examine the relationship between IWMs of caregiving for different recipients and these influences toward parental sensitivity. From the results, caregiving IWM have high correlations between different recipients. In addition, attachment and caregiving toward marital partner show unique influences on sensitivity

Carbon fiber textile composites using highly-polymerized thermoplastic epoxy: effect of molecular weight of epoxy on the mechanical performance of composites

The purpose of this study is to reveal the effect of resin molecular weight on the mechanical properties of carbon fabric reinforced thermoplastic epoxy composites (CFRTP). An extensive experimental campaign allowed understanding the influence of the thermoplastic resin with weight-average molecular weight (Mw) ranging from 14,000 to 117,000. Different loading conditions were applied, including quasi-static and cyclic three point bending and tensile loadings. Moreover, fiber-matrix adhesion and interlaminar fracture toughness were measured by micro-droplet and End Notched Flexure (ENF) mode II fracture tests. The mechanical responses highlighted the considerable improvements of the composite performances for thermoplastic epoxy with high polymerization (high molecular weight). It is also shown that an excessive polymerization, greater than 60,000 Mw, is not necessary for composite performance