Abstract Objectives To evaluate the effect of different cement types on the incidence of failure and loss of retention of zirconia and metal‐ceramic single crowns (SCs) cemented on implant abutments. ...Methods We placed 567 implant‐supported SCs in 358 patients and retrospectively evaluated long‐term retention for up to 12.8 years. The frameworks were made from metal alloy ( n = 307) or zirconia ( n = 260). SCs were cemented with permanent (glass‐ionomer cement; n = 376) or semipermanent cement (zinc oxide non‐eugenol cement; n = 191) on standardized ( n = 446) or customized ( n = 121) abutments. Kaplan–Meier curves were used to calculate the incidence of decementation. Differences between survival curves were assessed with log‐rank tests. Cox‐regression analysis was performed to evaluate multiple risk factors. Results Of the 567 SCs, 22 failed because of technical complications and four because of implant loss. Loss of retention was observed in 50 SCs. Analysis revealed a 7% probability of loss of retention for zirconia and 16% for metal‐ceramic SCs after 10 years ( p = .011). After 5 years, loss of retention was higher for standardized abutments than for customized abutments ( p = .014). The probability of loss of retention was higher with semipermanent than with permanent cement ( p = .001). Cox‐regression analysis revealed semipermanent cement as the only significant risk factor for SC failure ( p = .026). Conclusions In contrast to semipermanent cement, permanent cement provides acceptable long‐term retention of cemented implant‐supported SCs. These possible positive effects of customized abutments have to be controlled with larger sample sizes.
ABSTRACT
GRANDMA (Global Rapid Advanced Network Devoted to the Multi-messenger Addicts) is a network of 25 telescopes of different sizes, including both photometric and spectroscopic facilities. The ...network aims to coordinate follow-up observations of gravitational-wave (GW) candidate alerts, especially those with large localization uncertainties, to reduce the delay between the initial detection and the optical confirmation. In this paper, we detail GRANDMA’s observational performance during Advanced LIGO/Advanced Virgo Observing Run 3 (O3), focusing on the second part of O3; this includes summary statistics pertaining to coverage and possible astrophysical origin of the candidates. To do so, we quantify our observation efficiency in terms of delay between GW candidate trigger time, observations, and the total coverage. Using an optimized and robust coordination system, GRANDMA followed-up about 90 per cent of the GW candidate alerts, that is 49 out of 56 candidates. This led to coverage of over 9000 deg2 during O3. The delay between the GW candidate trigger and the first observation was below 1.5 h for 50 per cent of the alerts. We did not detect any electromagnetic counterparts to the GW candidates during O3, likely due to the very large localization areas (on average thousands of degrees squares) and relatively large distance of the candidates (above 200 Mpc for 60 per cent of binary neutron star, BNS candidates). We derive constraints on potential kilonova properties for two potential BNS coalescences (GW190425 and S200213t), assuming that the events’ locations were imaged.
In this article we further constrain the phenomenology and progenitor properties of this peculiar GRB by performing a multiband temporal and spectral analysis of both the prompt and the afterglow ...emission. We use proprietary and publicly available data from Swift, Konus WIND, XMM-Newton, and TAROT, as well as from other ground-based optical and radio telescopes. We find some peculiar properties that are possibly connected to the exceptional nature of this burst, namely: (1) an unprecedented large optical delay of 410 + or - 50 s between the peak time in gamma-rays and the peak time in the optical of a marked multiwavelength flare; (2) multiwavelength prompt emission spectral modeling requires a certain amount of dust in the circumburst environment. (3) we detect the presence of a hard spectral extra power-law component at the end of the X-ray steep steep decay phase and before the start of the X-ray afterglow, which has never been revealed thus far in past GRBs.
The most energetic gamma-ray bursts (GRBs) are remarkable sources releasing huge amounts of energy on short timescales. Their prompt emission, which usually lasts a few seconds, is so bright that it ...is visible across the whole observable universe. Studying these extreme events may provide clues on the nature of GRB progenitors and on the physical processes at work in relativistic jets. In this paper, we study the bright end of the isotropic energy distribution of long GRBs. We use two samples of long GRBs with redshift detected by Fermi/GBM or Konus-Wind, two instruments that measure the spectral shape and the energetics of the prompt emission accurately. We focus on GRBs within a range of redshifts z = 1-5, a volume that contains a large number of energetic GRBs, and we propose a simple method to reconstruct the bright end of the GRB energy distribution from the observed one. We find that the GRB energy distribution cannot be described by a simple power law but requires a strong cutoff above 1 - 3 × 10 54 erg. We attribute this feature to an intrinsic limit on the energy per unit of solid angle radiated by GRBs.
RR Lyr is one of the most studied variable stars. Its light curve has been regularly monitored since the discovery of its periodic variability in 1899. The analysis of all observed maxima allows us ...to identify two primary pulsation states, defined as pulsation over a long (P
0 longer than 0.56684 d) and a short (P
0 shorter than 0.56682 d) primary pulsation period. These states alternate with intervals of 13–16 yr, and are well defined after 1943. The 40.8-d periodical modulations of the amplitude and the period (i.e. the Blazhko effect) were noticed in 1916. We provide homogeneous determinations of the Blazhko period in the different primary pulsation states. The Blazhko period does not follow the variations of P
0 and suddenly diminished from 40.8 d to around 39.0 d in 1975. The monitoring of these periodicities deserved, and still deserves, a continuous and intensive observational effort. For this purpose, we have built dedicated, transportable and autonomous small instruments, Very Tiny Telescopes (VTTs), to observe the times of maximum brightness of RR Lyr. As immediate results, the VTTs recorded the last change of the P
0 state in mid-2009 and extended the time coverage of the Kepler observations, thus recording a maximum O − C amplitude of the Blazhko effect at the end of 2008, followed by the historically smallest O − C amplitude in late 2013. This decrease is still ongoing and the VTTs are ready to monitor the expected increase in the next few years.
We present observations of the possible short GRB 180418A in γ-rays, X-rays, and in the optical. Early optical photometry with the TAROT and RATIR instruments shows a bright peak ( 14.2 AB mag) ...between T + 28 and T + 90 s that we interpret as the signature of a reverse shock. Later observations can be modeled by a standard forward shock model and show no evidence of a jet break, allowing us to constrain the jet collimation to θj > 7°. Using deep late-time optical observations, we place an upper limit of r > 24 AB mag on any underlying host galaxy. The detection of the afterglow in the Swift UV filters constrains the GRB redshift to z < 1.3 and places an upper bound on the γ-ray isotropic equivalent energy Eγ,iso < 3 × 1051 erg. The properties of this GRB (e.g., duration, hardness ratio, energy, and environment) lie at the intersection between short and long bursts, and we cannot conclusively identify its type. We estimate that the probability that it is drawn from the population of short GRBs is 10%-30%.
Twenty-six years after the arrival of “killer bees” in Arizona, the entire state with the exception of high elevations in the north is populated with this bee variety and 11 people have died at the ...scene of massive bee attacks.
Because of the aggressive behavior of these bees we studied bee stings reported to the Arizona Poison and Drug Information Center. The center received 399 calls regarding 312 victims of bee stings from January 2017 to June 2019. Calls originated from private residences and emergency centers.
Stings occurred at victims’ home residences in 272 (84.7%) of cases and 24 (7.5%) in public areas; 251 people suffered 1 sting; 42 individuals, 2-10 stings, 4 had 11-49 stings, and 13 individuals had >50 stings (so-called massive stinging). Three individuals were admitted to intensive care units (ICU) and one 35-year-old man died of anaphylaxis after 1 sting; moderate clinical effects occurred in 32 individuals including 6 admitted to the hospital but not in the intensive care unit. Anaphylaxis occurred in 30 (9.6%) of individuals, 16 receiving 1 sting. Toxic effects, tachycardia, elevated creatinine, or rhabdomyolysis occurred in 13 (4.2%) individuals.
In the past, individuals stung more than 50 times were beekeepers working with European honeybees, whereas, in the current era, single as well as massive stings are the result of feral “killer bees.” This change in epidemiology requires a new approach to sting victims: those with massive stinging should be evaluated and observed for anaphylaxis and serial laboratory values obtained for days to detect the toxic effects of envenomation.
Abstract
Arctic-boreal regions are experiencing major anthropogenic disturbances in addition to intensifying natural disturbance regimes as a consequence of climate change. Oil and natural gas (OG) ...activities are extensive in the Arctic-boreal region of western North America, a large portion of which is underlain by permafrost. The total number and distribution of OG wells and their potential fate remain unclear. Consequently, the collective impacts of OG wells on natural and cultural resources, human health and emissions of methane (CH
4
), are poorly understood. Using public OG well databases, we analysed the distribution of OG wells drilled between 1984 and 2018 across the Core Domain of the NASA Arctic-Boreal Vulnerability Experiment (‘ABoVE domain’). We identified 242 007 OG wells drilled as of 2018 in the ABoVE domain, of which almost two thirds are now inactive or abandoned OG wells. We found that annual drilling has increased from 269 to 8599 OG wells from 1984 to 2014 with around 1000, 700 and 1800 OG wells drilled annually in evergreen forest, deciduous forest and herbaceous land cover types, respectively. 65 588 OG well sites were underlain by permafrost in 2012. Fugitive CH
4
emissions from active and abandoned OG wells drilled in the Canadian portion of the ABoVE domain accounted for approximately 13% of the total anthropogenic CH
4
emissions in Canada in 2018. Our analysis identified OG wells as an anthropogenic disturbance in the ABoVE domain with potentially non-negligible consequences to local populations, ecosystems, and the climate system.
HIV-infected older individuals may have a diminished immune response because of exhaustion/immune aging of T-cells. Therefore, we have investigated HIV-specific CD4 and CD8 T-cell responses in 100 ...HIV-infected patients (HIV.sup.+) who have aged on long-term antiretroviral therapy (ART) and achieved controlled viremia (mostly undetectable viral load; 92 patients with 20 to 40 HIV RNA copies/mL and 8 60 to 100) and improved CD4 T-cell counts. We show that the median frequencies of HIV-specific CD4.sup.+ and CD8.sup.+ IFN-gamma T-cells were higher in HIV.sup.+ than uninfected individuals (HIV.sup.- ), including increasing levels of IFN-gammaproduced by CD4.sup.+ T-cells and decreasing levels by CD8.sup.+ T-cells with increasing CD4 T-cell counts in HIV.sup.+ . No correlation was found between T-cell responses and varying levels of undetectable viremia. HIV-specific TNF-alpha made by CD8.sup.+ T-cells was higher in HIV.sup.+ than HIV.sup.-, including decreasing levels with increasing CD4 T-cell counts in HIV.sup.+ . Furthermore, the CD8.sup.+ T-cell mediators, CD107a and Granzyme-B, were higher in HIV.sup.+ than HIV.sup.-, and decreased with increasing CD4 T-cell counts in HIV.sup.+ . Remarkably, HIV-specific CD8 T-cells produced decreasing levels of IFN-gammawith increasing age of HIV.sup.+, including decreased levels of CD107a and Granzyme-B in older HIV.sup.+ . However, HIV-specific CD8.sup.+ T-cells produced increasing levels of TNF-alpha with increasing age of the HIV.sup.+, suggesting continued inflammation. In conclusion, HIV.sup.+ with controlled viremia on long-term ART and with higher CD4 T-cell counts showed reduced HIV-specific CD8 T-cell responses as compared to those with lower CD4 T-cell counts, and older HIV.sup.+ exhibited decreasing levels of CD8 T-cell responses with increasing age.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Several studies have shown an increased accumulation of terminally differentiated T cells during HIV infection, suggestive of exhaustion/senescence, causing dysregulation of T cell homeostasis and ...function and rapid HIV disease progression. We have investigated whether long-term antiretroviral therapy (ART), which controls viremia and restores CD4 T cell counts, is correlated with reduction in terminally differentiated T cells, improved ratios of naïve to memory and function of T cells in 100 virologically controlled HIV-infected patients. We show that while the median frequencies of terminally differentiated CD4+ and CD8+ T cells (CD28-, CD27-, CD57+ and CD28-CD57+), were higher in the virologically controlled HIV-infected patients' cohort compared with uninfected individuals' cohort, the frequencies of these cells significantly decreased with increasing CD4 T cell counts in HIV-infected patients. Although, the naïve CD4+ and CD8+ T cells were lower in HIV patients' cohort than uninfected cohort, there was a significant increase in both naïve CD4+ and CD8+ T cells with increasing CD4 T cell counts in HIV-infected patients. The underlying mechanism behind this increased naïve CD4+ and CD8+ T cells in HIV-infected patients was due to an increase in recent thymic emigrants, CD4+CD31+, as compared to CD4+CD31-. The CD4+ T cells of HIV-infected patients produced cytokines, including IL-2, IL-10 and IFN-γ comparable to uninfected individuals. In conclusion, virologically controlled HIV-infected patients on long-term ART show a significant reduction in terminally differentiated T cells, suggestive of decreased exhaustion/senescence, and improvement in the ratios of naïve to memory and function of T cells.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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