Bond Strength of Composite Resin to Bleached Dentin: Effect of Using Antioxidant Versus Buffering Agent

Objective: Application of sodium ascorbate as an antioxidant and calcium hydroxide as a buffering agent following intracoronal bleaching has been recommended. The aim of this study was to investigate the effect of using the mentioned materials onshear bond strength of composite resin to the bleached dentin.Materials and Methods: In this in vitro investigation, sixty human sound premolars were divided randomly into five groups (n=12). Occlusal dentin surfaces were exposed.The negative control (NC) group was not bleached and the other groups were bleached with 35% hydrogen peroxide gel for 5 days. Afterwards, compositecylinders were built up in the positive control (PC) group immediately after bleaching,in the delay bonding (DB) group after one week, in the sodium ascorbate (SA)and calcium hydroxide (CH) groups after 40 hours of treatment with the materials.Then, the samples were stored in 37°C for 24 hours. The specimens were thermocycled (5-55°C, 500 cycles), subjected to shear bond testing by universal machine.The data were analyzed by One-Way ANOVA and Duncan tests (a =0.05).Results: There was a significant difference between PC and CH groups in comparison with the other groups (p<0.05), but the difference among other groups was not significant (p>0.05).Conclusion: Application of sodium ascorbate could significantly increase the bond strength of composite resin to bleached dentin, while the use of calcium hydroxide did not affect bond strength

Optimized Microstrip Antennas with Metamaterial Superstrates Using Particle Swarm Optimization

Two new designs of compact microstrip antennas, where metamaterials are placed on structure as superstrate, are proposed. The newly designed metamaterial unit cell and antenna feed position optimized by particle swarm optimization. It was found that the characteristics of novel microstrip antennas with designed metamaterials placed on the superstrate are comparable to the conventional patch antennas, while their gain, directivity and radiating efficiency are noticeably improved. Gain of microstrip antenna is increased 3dB to 4dB and level of back lobe is decresed

Competitive Intelligence Text Mining: Words Speak

Competitive intelligence (CI) has become one of the major subjects for researchers in recent years. The present research is aimed to achieve a part of the CI by investigating the scientific articles on this field through text mining in three interrelated steps. In the first step, a total of 1143 articles released between 1987 and 2016 were selected by searching the phrase "competitive intelligence" in the valid databases and search engines; then, through reviewing the topic, abstract, and main text of the articles as well as screening the articles in several steps, the authors eventually selected 135 relevant articles in order to perform the text mining process. In the second step, pre-processing of the data was carried out. In the third step, using non-hierarchical cluster analysis (k-means), 5 optimum clusters were obtained based on the Davies–Bouldin index, for each of which a word cloud was drawn; then, the association rules of each cluster was extracted and analyzed using the indices of support, confidence, and lift. The results indicated the increased interest in researches on CI in recent years and tangibility of the strong and weak presence of the developed and developing countries in formation of the scientific products; further, the results showed that information, marketing, and strategy are the main elements of the CI that, along with other prerequisites, can lead to the CI and, consequently, the economic development, competitive advantage, and sustainability in market

Evaluation of intranasal dexmedetomidine in providing moderate sedation in patients undergoing ERCP: A randomized controlled trial

Background and purpose: Endoscopic retrograde cholangiopancreatography (ERCP) is usually performed under deep sedation. Respiratory depression and airway obstruction are the most dangerous complications of sedatives. Dexmedetomidine is a drug that does not cause respiratory depression so, this study evaluated the efficacy of nasal dexmedetomidine in inducing moderate sedation in patients undergoing ERCP. Materials and methods: In a double blind randomized controlled trial, the patients candidate for ERCP in Firoozgar hospital, were divided into two groups. Group I received normal saline while in group II dexmedetomidine 1μg/kg was administered intranasaly. Also, intravenous midazolam and fentanyl, and if needed, propofol were used for induction of sedation. Then total use of sedative drugs, hemodynamic parameters, patient and physician satisfaction and side effects of treatment were documented. Results: There were no significant differences in age, sex and BMI between the two groups. Mean use of midazolam and fentanyl was almost similar in two groups but the use of propofol was lower in group II (P= 0.002). The mean heart rate was found to be lower in the group receiving dexmedetomidine but systolic and diastolic blood pressure were almost similar in two groups (P> 0.05). Compared with the results in group I, the patients and physicians in group II were more satisfied with dexmedetomidine. Conclusion: Dexmedetomidine as an adjuvant drug for sedation in patients undergoing ERCP could reduce the need for other sedatives, and also satisfy both the patients and therapists. © 2016, Mazandaran University of Medical Sciences. All Rights reserved

Elevated gamma-glutamyl transferase is associated with subclinical inflammation independent of cardiometabolic risk factors in an asymptomatic population: a cross-sectional study

BACKGROUND: Serum Gamma-Glutamyl Transferase (GGT), a marker of oxidative stress, has been suggested to be independently associated with cardiovascular disease (CVD) events. We examined the association of serum GGT levels with the burden of subclinical inflammation across a spectrum of metabolic conditions. METHODS: We evaluated 5,446 asymptomatic subjects (43 ± 10 years, 78 % males) who had an employer-sponsored physical between 2008 and 2010. Highly sensitivity C-reactive protein (hsCRP) was measured as a marker of underlying systemic inflammation. A linear regression of GGT quartiles with log transformed hsCRP and a multivariate logistic regression of GGT quartiles with elevated hsCRP (≥3 mg/L) were performed. RESULTS: Median GGT was 31 IU/l (IQR: 22–45 IU/l), 1025 (19 %) had hsCRP ≥ 3 mg/L. The median hsCRP increased with GGT quartiles (Q1: 0.9 mg/L, Q2: 1.1 mg/L, Q3: 1.4 mg/L, Q4: 1.6 mg/L, p < 0.001). Linear regression models showed GGT in the fourth quartile was associated with 0.45 mg/L (95 % CI 0.35, 0.54, p < 0.001) increase in log transformed hsCRP adjusting for risk factors. The Odds Ratio (OR) for an elevated hsCRP (≥3 mg/L) also increased with higher GGT quartiles; GGT Q2 1.44 (95 % CI 1.12, 1.85), GGT Q3 1.89 (95 % CI 1.45, 2.46), GGT Q4 2.22 (95 % CI 1.67, 2.95), compared to GGT Q1. The strength of association increased in the presence of and combination of metabolic conditions. CONCLUSION: In our cohort of asymptomatic individuals a higher serum GGT level was independently associated with increased burden of subclinical inflammation across metabolic states. These findings may explain GGT association with increased CVD risk

Black Hole Mass Estimates Based on CIV are Consistent with Those Based on the Balmer Lines

Using a sample of high-redshift lensed quasars from the CASTLES project with observed-frame ultraviolet or optical and near-infrared spectra, we have searched for possible biases between supermassive black hole (BH) mass estimates based on the CIV, Halpha and Hbeta broad emission lines. Our sample is based upon that of Greene, Peng & Ludwig, expanded with new near-IR spectroscopic observations, consistently analyzed high S/N optical spectra, and consistent continuum luminosity estimates at 5100A. We find that BH mass estimates based on the FWHM of CIV show a systematic offset with respect to those obtained from the line dispersion, sigma_l, of the same emission line, but not with those obtained from the FWHM of Halpha and Hbeta. The magnitude of the offset depends on the treatment of the HeII and FeII emission blended with CIV, but there is little scatter for any fixed measurement prescription. While we otherwise find no systematic offsets between CIV and Balmer line mass estimates, we do find that the residuals between them are strongly correlated with the ratio of the UV and optical continuum luminosities. Removing this dependency reduces the scatter between the UV- and optical-based BH mass estimates by a factor of approximately 2, from roughly 0.35 to 0.18 dex. The dispersion is smallest when comparing the CIV sigma_l mass estimate, after removing the offset from the FWHM estimates, and either Balmer line mass estimate. The correlation with the continuum slope is likely due to a combination of reddening, host contamination and object-dependent SED shapes. When we add additional heterogeneous measurements from the literature, the results are unchanged.Comment: Accepted for publication in The Astrophysical Journal. 37 text pages + 8 tables + 23 figures. Updated with comments by the referee and with a expanded discussion on literature data including new observation

Infrared Narrow-Band Tomography of the Local Starburst NGC 1569 with LBT/LUCIFER

We used the near-IR imager/spectrograph LUCIFER mounted on the Large Binocular Telescope (LBT) to image, with sub-arcsec seeing, the local dwarf starburst NGC 1569 in the JHK bands and HeI 1.08 micron, [FeII] 1.64 micron and Brgamma narrow-band filters. We obtained high-quality spatial maps of HeI, [FeII] and Brgamma emission across the galaxy, and used them together with HST/ACS images of NGC 1569 in the Halpha filter to derive the two-dimensional spatial map of the dust extinction and surface star formation rate density. We show that dust extinction is rather patchy and, on average, higher in the North-West (NW) portion of the galaxy [E_g(B-V) = 0.71 mag] than in the South-East [E_g(B-V) = 0.57 mag]. Similarly, the surface density of star formation rate peaks in the NW region of NGC 1569, reaching a value of about 4 x 10^-6 M_sun yr^-1 pc^-2. The total star formation rate as estimated from the integrated, dereddened Halpha luminosity is about 0.4 M_sun yr^-1, and the total supernova rate from the integrated, dereddened [FeII] luminosity is about 0.005 yr^-1 (assuming a distance of 3.36 Mpc). The azimuthally averaged [FeII]/Brgamma flux ratio is larger at the edges of the central, gas-deficient cavities (encompassing the super star clusters A and B) and in the galaxy outskirts. If we interpret this line ratio as the ratio between the average past star formation (as traced by supernovae) and on-going activity (represented by OB stars able to ionize the interstellar medium), it would then indicate that star formation has been quenched within the central cavities and lately triggered in a ring around them. The number of ionizing hydrogen and helium photons as computed from the integrated, dereddened Halpha and HeI luminosities suggests that the latest burst of star formation occurred about 4 Myr ago and produced new stars with a total mass of ~1.8 x 10^6 M_sun. [Abridged]Comment: accepted for publication in A

Antimicrobial de-escalation in the critically ill patient and assessment of clinical cure: the DIANA study

Purpose: The DIANA study aimed to evaluate how often antimicrobial de-escalation (ADE) of empirical treatment is performed in the intensive care unit (ICU) and to estimate the effect of ADE on clinical cure on day 7 following treatment initiation. Methods: Adult ICU patients receiving empirical antimicrobial therapy for bacterial infection were studied in a prospective observational study from October 2016 until May 2018. ADE was defined as (1) discontinuation of an antimicrobial in case of empirical combination therapy or (2) replacement of an antimicrobial with the intention to narrow the antimicrobial spectrum, within the first 3&nbsp;days of therapy. Inverse probability (IP) weighting was used to account for time-varying confounding when estimating the effect of ADE on clinical cure. Results: Overall, 1495 patients from 152 ICUs in 28 countries were studied. Combination therapy was prescribed in 50%, and carbapenems were prescribed in 26% of patients. Empirical therapy underwent ADE, no change and change other than ADE within the first 3&nbsp;days in 16%, 63% and 22%, respectively. Unadjusted mortality at day 28 was 15.8% in the ADE cohort and 19.4% in patients with no change [p = 0.27; RR 0.83 (95% CI 0.60\u20131.14)]. The IP-weighted relative risk estimate for clinical cure comparing ADE with no-ADE patients (no change or change other than ADE) was 1.37 (95% CI 1.14\u20131.64). Conclusion: ADE was infrequently applied in critically ill-infected patients. The observational effect estimate on clinical cure suggested no deleterious impact of ADE compared to no-ADE. However, residual confounding is likely

The CARMENES search for exoplanets around M dwarfs High-resolution optical and near-infrared spectroscopy of 324 survey stars

The CARMENES radial velocity (RV) survey is observing 324 M dwarfs to search for any orbiting planets. In this paper, we present the survey sample by publishing one CARMENES spectrum for each M dwarf. These spectra cover the wavelength range 520–1710 nm at a resolution of at least R >80 000, and we measure its RV, Hα emission, and projected rotation velocity. We present an atlas of high-resolution M-dwarf spectra and compare the spectra to atmospheric models. To quantify the RV precision that can be achieved in low-mass stars over the CARMENES wavelength range, we analyze our empirical information on the RV precision from more than 6500 observations. We compare our high-resolution M-dwarf spectra to atmospheric models where we determine the spectroscopic RV information content, Q, and signal-to-noise ratio. We find that for all M-type dwarfs, the highest RV precision can be reached in the wavelength range 700–900 nm. Observations at longer wavelengths are equally precise only at the very latest spectral types (M8 and M9). We demonstrate that in this spectroscopic range, the large amount of absorption features compensates for the intrinsic faintness of an M7 star. To reach an RV precision of 1 m s−1 in very low mass M dwarfs at longer wavelengths likely requires the use of a 10 m class telescope. For spectral types M6 and earlier, the combination of a red visual and a near-infrared spectrograph is ideal to search for low-mass planets and to distinguish between planets and stellar variability. At a 4 m class telescope, an instrument like CARMENES has the potential to push the RV precision well below the typical jitter level of 3–4 m s−1