Abstract During the last 25 yr, hundreds of binary stars and planets have been discovered toward the Galactic bulge by microlensing surveys. Thanks to a new generation of large-sky surveys, it is now ...possible to regularly detect microlensing events across the entire sky. The OMEGA Key Projet at the Las Cumbres Observatory carries out automated follow-up observations of microlensing events alerted by these surveys with the aim of identifying and characterizing exoplanets as well as stellar remnants. In this study, we present the analysis of the binary lens event Gaia20bof. By automatically requesting additional observations, the OMEGA Key Project obtained dense time coverage of an anomaly near the peak of the event, allowing characterization of the lensing system. The observed anomaly in the lightcurve is due to a binary lens. However, several models can explain the observations. Spectroscopic observations indicate that the source is located at ≤2.0 kpc, in agreement with the parallax measurements from Gaia. While the models are currently degenerate, future observations, especially the Gaia astrometric time series as well as high-resolution imaging, will provide extra constraints to distinguish between them.
Gravitational microlensing is a phenomenon that allows us to observe dark remnants of stellar evolution even if they no longer emit electromagnetic radiation. In particular, it can be useful to ...observe solitary neutron stars or stellar-mass black holes, providing a unique window through which to understand stellar evolution. Obtaining direct mass measurements with this technique requires precise observations of both the change in brightness and the position of the microlensed star and the European Space Agency's Gaia satellite can provide both. We analysed events published in Gaia Data Release 3 (GDR3) microlensing catalogue using publicly available data from different surveys. Here we describe our selection of candidate dark lenses, where we suspect the lens is a white dwarf (WD), a neutron star (NS), a black hole (BH), or a mass-gap object, with a mass in a range between the heaviest NS and the least massive BH. We estimated the mass of the lenses using information obtained from the best-fitting microlensing models, the Galactic model and the expected distribution of the parameters. We found eight candidates for WDs or NS, and two mass-gap objects.
Quantum technologies, including communication and computing, are enabled by optical fields. Indeed, photons are excellent for carrying quantum information at long distances. Including of material ...systems in optical quantum networks is desired in order to enable additional functionalities, such as long-distance entanglement distribution or advanced quantum computing via interactions. We review applications of atomic ensembles in the quantum optical and hybrid optical-microwave networks.
Identifying black holes is essential for comprehending the development of stars and uncovering novel principles of physics. Gravitational microlensing provides an exceptional opportunity to examine ...an undetectable population of black holes in the Milky Way. In particular, long-lasting events are likely to be associated with massive lenses, including black holes. We present an analysis of the Gaia18ajz microlensing event, reported by the Gaia Science Alerts system, which has exhibited a long timescale and features indicative of the annual microlensing parallax effect. Our objective is to estimate the parameters of the lens based on the best-fitting model. We utilized photometric data obtained from the Gaia satellite and terrestrial observatories to investigate a variety of microlensing models and calculate the most probable mass and distance to the lens, taking into consideration a Galactic model as a prior. Subsequently, weapplied a mass-brightness relation to evaluate the likelihood that the lens is a main sequence star. We also describe the DarkLensCode (DLC), an open-source routine which computes the distribution of probable lens mass, distance and luminosity employing the Galaxy priors on stellar density and velocity for microlensing events with detected microlensing parallax. We modelled Gaia18ajz event and found its two possible models with most likely Einstein timescale of \(316^{+36}_{-30}\) days and \(299^{+25}_{-22}\) days. Applying Galaxy priors for stellar density and motion, we calculated the most probable lens mass of \(4.9^{+5.4}_{-2.3} M_\odot\) located at \(1.14^{+0.75}_{-0.57}\,\text{kpc}\) or \(11.1^{+10.3}_{-4.7} M_\odot\) located at \(1.31^{+0.80}_{-0.60}\,\text{kpc}\). Our analysis of the blended light suggests that the lens is likely a dark remnant of stellar evolution, rather than a main sequence star.
During the last 25 years, hundreds of binary stars and planets have been discovered towards the Galactic Bulge by microlensing surveys. Thanks to a new generation of large-sky surveys, it is now ...possible to regularly detect microlensing events across the entire sky. The OMEGA Key Projet at the Las Cumbres Observatory carries out automated follow-up observations of microlensing events alerted by these surveys with the aim of identifying and characterizing exoplanets as well as stellar remnants. In this study, we present the analysis of the binary lens event Gaia20bof. By automatically requesting additional observations, the OMEGA Key Project obtained dense time coverage of an anomaly near the peak of the event, allowing characterization of the lensing system. The observed anomaly in the lightcurve is due to a binary lens. However, several models can explain the observations. Spectroscopic observations indicate that the source is located at \(\le2.0\) kpc, in agreement with the parallax measurements from Gaia. While the models are currently degenerate, future observations, especially the Gaia astrometric time series as well as high-resolution imaging, will provide extra constraints to distinguish between them.
Abstract Study question Are elevated doses of follicle stimulating hormone (FSH) detrimental to oocyte maturation and the efficacy of ovarian stimulation in good responders? Summary answer Elevated ...FSH levels reduce the number of oocytes collected from good responders. Patients receiving lower total FSH doses had optimal and higher maturation rates. What is known already There is an inverse relationship between the dose of exogeneous follicle stimulating hormone (FSH) and the number of oocytes retrieved. This relationship is independent of patient age or health and implies that excessive FSH doses administered during artificial reproductive technologies (ART) may be detrimental to oocyte maturation. Study design, size, duration This three-year retrospective, multicenter study included 1,075 oocyte donor cycles performed in three IVF clinics between January 2020 and December 2023 with at least a six-month interval between each cycle. Donors were all considered good responders and divided according to the total dose of FSH received per cycle (n = 289 cycles with <1,700 IU FSH; 400 cycles with 1,700 to 2,900 IU FSH; and 386 cycles with >2,900 IU FSH). Participants/materials, setting, methods The mean oocyte donor age was between 26.13 and 27.45 years old. The mean BMI for all three groups was 21. The association between the total FSH dose and serum anti-Müllerian hormone (AMH) level, follicle-to-oocyte index (FOI), number of oocytes retrieved, and oocyte maturation was assessed using the Student’s t-test (parametric) or Mann-Whitney-U test (non-parametric). Main results and the role of chance There were no significant differences in the mean serum AMH levels (5.31 vs. 5.27 vs. 5.13 ng/mL, respectively) and FOI (81.1 vs. 80.2 vs. 81.5, respectively) of patients who received different total doses of FSH. However, the number of oocytes retrieved from each group was inversely related to the total dose of FSH received (24.4 vs. 22.9 vs. 21.01 oocytes, respectively; p < 0.05) Limitations, reasons for caution Full characterization of the oocytes and their developmental potential was outside the scope of this retrospective study. Wider implications of the findings Gaining a better understanding of the complex interplay of gonadotropins throughout folliculogenesis can help optimize ovarian stimulation protocols to maximize the number of mature and developmentally competent oocytes recovered for clinical use. Trial registration number non applicable
Summary Background Use of cetuximab, a monoclonal antibody targeting the epidermal growth factor receptor (EGFR), has the potential to increase survival in patients with advanced non-small-cell lung ...cancer. We therefore compared chemotherapy plus cetuximab with chemotherapy alone in patients with advanced EGFR-positive non-small-cell lung cancer. Methods In a multinational, multicentre, open-label, phase III trial, chemotherapy-naive patients (≥18 years) with advanced EGFR-expressing histologically or cytologically proven stage wet IIIB or stage IV non-small-cell lung cancer were randomly assigned in a 1:1 ratio to chemotherapy plus cetuximab or just chemotherapy. Chemotherapy was cisplatin 80 mg/m2 intravenous infusion on day 1, and vinorelbine 25 mg/m2 intravenous infusion on days 1 and 8 of every 3-week cycle) for up to six cycles. Cetuximab—at a starting dose of 400 mg/m2 intravenous infusion over 2 h on day 1, and from day 8 onwards at 250 mg/m2 over 1 h per week—was continued after the end of chemotherapy until disease progression or unacceptable toxicity had occurred. The primary endpoint was overall survival. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov , number NCT00148798. Findings Between October, 2004, and January, 2006, 1125 patients were randomly assigned to chemotherapy plus cetuximab (n=557) or chemotherapy alone (n=568). Patients given chemotherapy plus cetuximab survived longer than those in the chemotherapy-alone group (median 11·3 months vs 10·1 months; hazard ratio for death 0·871 95% CI 0·762–0·996; p=0·044). The main cetuximab-related adverse event was acne-like rash (57 10% of 548, grade 3). Interpretation Addition of cetuximab to platinum-based chemotherapy represents a new treatment option for patients with advanced non-small-cell lung cancer. Funding Merck KGaA.
Cultivation conditions for recombinant Escherichia coli strain KPR-42 producing human gamma-interferon in liquid nutrient medium were optimized. Glucose content in the medium was optimized by the ...reason that glucose catabolism products cause the medium acidification. That permitted to prolong fermentation time and increase recombinant protein content in the cells by 23-25%, avoiding expendable enrichment of the medium by nutrient components.
In recent years, treatment approaches in patients with HL are actively discussed. The actual issue remains the combination therapy or possible avoiding of radiation therapy to reduce toxicity and the ...occurrence of secondary tumors in the future. In a number of studies, the prognostic role of interim and end of treatment PET/CT is investigated as a disease prognostic risk factor. In this article, we presented analysis of interim-PET/CT in patients with primary HL as a prognostic marker. It was proved, that results of interim PET/CT show a highly predictive of the response to the first line therapy and could predict progression free survival (PFS).
