12 research outputs found
Titanium cold-trapping, near-solar abundance ratios for tens of species, and the first unambiguous detection of VO revealed on the ultra-hot Jupiter WASP-76b using MAROON-X
Stars and planetary system
Titanium cold-trapping, near-solar abundance ratios for tens of species, and the first unambiguous detection of VO revealed on the ultra-hot Jupiter WASP-76b using MAROON-X
Stars and planetary system
Hot Rocks Survey II. the thermal emission of TOI-1468 b reveals a bare hot rock
Context: terrestrial exoplanets orbiting nearby small cool stars, known as M dwarfs, are well suited for an atmospheric characterisation. Because the intense X-ray and UV (XUV) irradiation from M dwarf host stars is strong, orbiting exoplanets are thought to be unable to retain primordial hydrogen- or helium-dominated atmospheres. However, it is currently unknown whether heavier secondary atmospheres can survive. Aims.: the aim of the Hot Rocks Survey programme is to determine whether exoplanets can retain secondary atmospheres in the presence of M dwarf hosts. In the sample of nine exoplanets in the programme, we aim to determine whether TOI-1468 b has a substantial atmosphere or is consistent with a low-albedo bare rock. Methods: the James Webb Space Telescope provides an opportunity to characterise the thermal emission with MIRI at 15 μm. The occultation of TOI-1468 b was observed three times. We compared our observations to atmospheric models that include varying amounts of CO2 and H2O. Results: the observed occultation depths for the individual visits are 239±52 ppm, 341±53 ppm, and 357±52 ppm. A joint fit yields an occultation depth of 311±31 ppm. The thermal emission is mostly consistent with no atmosphere and a zero Bond albedo at a confidence level of 1.65, or a blackbody at a brightness temperature of 1024 ± 78 K. A pure CO2 or H2O atmosphere with a surface pressure above 1 bar is ruled out at higher than 3.Conclusions: surprisingly, the surface of TOI-1468 b is marginally hotter than expected. This indicates an additional source of energy on the planet. This source might originate from a temperature inversion or induction heating, or it might be an instrumental artefact. The results within the Hot Rocks Survey build on the legacy of studying the atmospheres of exoplanets around M dwarfs. The outcome of this survey will prove useful to the large-scale survey of M dwarfs that was recently approved by the STScI.</p
Hot Rocks Survey I: A possible shallow eclipse for LHS 1478 b
Context. M-dwarf systems offer an opportunity to study terrestrial exoplanetary atmospheres due to their small size and cool temperatures. However, the extreme conditions imposed by these host stars raise a question about whether their close-in rocky planets are able to retain any atmosphere at all.
Aims. The Hot Rocks Survey aims to answer this question by targeting nine different M-dwarf rocky planets spanning a range of planetary and stellar properties. Of these, LHS 1478 b orbits an M3-type star, has an equilibrium temperature of Teq = 585 K, and receives 21 times Earth’s instellation.
Methods. We observed two secondary eclipses of LHS 1478 b using photometric imaging at 15 µm using the Mid-Infrared Instrument on the James Webb Space Telescope (JWST MIRI) to measure thermal emission from the dayside of the planet. We compared these values to atmospheric models to evaluate potential heat transport and CO2 absorption signatures.
Results. We find that a secondary eclipse depth of 138 ± 53 ppm at the expected time for a circular orbit is preferred over a null model at 2.8σ, a moderate detection, though dynamical models do favour a non-eccentric orbit for this planet. The second observation results in a non-detection due to significantly larger unexplained systematics. Based on the first observation alone, we can reject the null hypothesis of the dark (zero Bond albedo) no atmosphere bare rock model with a confidence level of 3.3σ, though for AB = 0.2 the significance decreases to 2.1σ. The tentative secondary eclipse depth is consistent with the majority of the atmospheric scenarios we considered, spanning CO2-rich atmospheres with surface pressures from 0.1 to 10 bar. However, we stress that the two observations from our programme do not yield consistent results, and more observations are needed to verify our findings. The Hot Rocks Survey serves as a relevant primer for future endeavours such as the Director’s Discretionary Time (DDT) Rocky Worlds programme
Nonpermissive HLA-DPB1 disparity is a significant independent risk factor for mortality after unrelated hematopoietic stem cell transplantation
The importance of donor-recipient human leukocyte antigen (HLA)-DPB1 matching for the clinical outcome of unrelated hematopoietic stem cell transplantation (HSCT) is controversial. We have previously described an algorithm for nonpermissive HLA-DPB1 disparities involving HLA-DPB1*0901,*1001,*1701,*0301,*1401,*4501, based on T-cell alloreactivity patterns. By revisiting the immunogenicity of HLA-DPB1*02, a modified algorithm was developed and retrospectively tested in 621 unrelated HSCTs facilitated through the Italian Registry for oncohematologic adult patients. The modified algorithm proved to be markedly more predictive of outcome than the original one, with significantly higher Kaplan-Meier probabilities of 2-year survival in permissive compared with nonpermissive transplantations (55% vs 39%, P = .005). This was the result of increased adjusted hazards of nonrelapse mortality (hazard ratio [HR] = 1.74; confidence interval [CI], 1.19-2.53; P = .004) but not of relapse (HR = 1.02; CI, 0.73-1.42; P = .92). The increase in the hazards of overall mortality by nonpermissive HLA-DPB1 disparity was similar in 10 of 10 (HR = 2.12; CI, 1.23-3.64; P = .006) and 9 of 10 allele-matched transplantations (HR = 2.21; CI, 1.28-3.80; P = .004), both in early-stage and in advanced-stage disease. These data call for revisiting current HLA matching strategies for unrelated HSCT, suggesting that searches should be directed up-front toward identification of HLA-DPB1 permissive, 10 of 10 or 9 of 10 matched donors
Nonpermissive HLA-DPB1 disparity is a significant independent risk factor for mortality after unrelated hematopoietic stem cell transplantation
Abstract
The importance of donor-recipient human leukocyte antigen (HLA)-DPB1 matching for the clinical outcome of unrelated hematopoietic stem cell transplantation (HSCT) is controversial. We have previously described an algorithm for nonpermissive HLA-DPB1 disparities involving HLA-DPB1*0901,*1001,*1701,*0301,*1401,*4501, based on T-cell alloreactivity patterns. By revisiting the immunogenicity of HLA-DPB1*02, a modified algorithm was developed and retrospectively tested in 621 unrelated HSCTs facilitated through the Italian Registry for oncohematologic adult patients. The modified algorithm proved to be markedly more predictive of outcome than the original one, with significantly higher Kaplan-Meier probabilities of 2-year survival in permissive compared with nonpermissive transplantations (55% vs 39%, P = .005). This was the result of increased adjusted hazards of nonrelapse mortality (hazard ratio [HR] = 1.74; confidence interval [CI], 1.19-2.53; P = .004) but not of relapse (HR = 1.02; CI, 0.73-1.42; P = .92). The increase in the hazards of overall mortality by nonpermissive HLA-DPB1 disparity was similar in 10 of 10 (HR = 2.12; CI, 1.23-3.64; P = .006) and 9 of 10 allele-matched transplantations (HR = 2.21; CI, 1.28-3.80; P = .004), both in early-stage and in advanced-stage disease. These data call for revisiting current HLA matching strategies for unrelated HSCT, suggesting that searches should be directed up-front toward identification of HLA-DPB1 permissive, 10 of 10 or 9 of 10 matched donors.
Comment i
Nonpermissive HLA-DPB1 disparity is a significant independent risk factor for mortality after unrelated hematopoietic stem cell transplantation.
The importance of donor-recipient human leukocyte antigen (HLA)-DPB1 matching for the clinical outcome of unrelated hematopoietic stem cell transplantation (HSCT) is controversial. We have previously described an algorithm for nonpermissive HLA-DPB1 disparities involving HLA-DPB1*0901,*1001,*1701,*0301,*1401,*4501, based on T-cell alloreactivity patterns. By revisiting the immunogenicity of HLA-DPB1*02, a modified algorithm was developed and retrospectively tested in 621 unrelated HSCTs facilitated through the Italian Registry for oncohematologic adult patients. The modified algorithm proved to be markedly more predictive of outcome than the original one, with significantly higher Kaplan-Meier probabilities of 2-year survival in permissive compared with nonpermissive transplantations (55% vs 39%, P = .005). This was the result of increased adjusted hazards of nonrelapse mortality (hazard ratio [HR] = 1.74; confidence interval [CI], 1.19-2.53; P = .004) but not of relapse (HR = 1.02; CI, 0.73-1.42; P = .92). The increase in the hazards of overall mortality by nonpermissive HLA-DPB1 disparity was similar in 10 of 10 (HR = 2.12; CI, 1.23-3.64; P = .006) and 9 of 10 allele-matched transplantations (HR = 2.21; CI, 1.28-3.80; P = .004), both in early-stage and in advanced-stage disease. These data call for revisiting current HLA matching strategies for unrelated HSCT, suggesting that searches should be directed up-front toward identification of HLA-DPB1 permissive, 10 of 10 or 9 of 10 matched donors
Nonpermissive HLA-DPB1 disparity is a significant independent risk factor for mortality after unrelated hematopoietic stem cell transplantation
The importance of donor-recipient human leukocyte antigen (HLA)-DPB1 matching for the clinical outcome of unrelated hematopoietic stem cell transplantation (HSCT) is controversial. We have previously described an algorithm for nonpermissive HLA-DPB1 disparities involving HLA-DPB1*0901,*1001,*1701,*0301,*1401,*4501, based on T-cell alloreactivity patterns. By revisiting the immunogenicity of HLA-DPB1*02, a modified algorithm was developed and retrospectively tested in 621 unrelated HSCTs facilitated through the Italian Registry for onco-hematologic adult patients. The modified algorithm proved to be markedly more predictive of outcome than the original one, with significantly higher KaplanMeier probabilities of 2-year survival in permissive compared with nonpermissive transplantations (55% vs 39%, P = .005). This was the result of increased adjusted hazards of nonrelapse mortality (hazard ratio [HR] = 1.74; confidence interval [CI], 1.19-2.53; P = .004) but not of relapse (HR = 1.02; CI, 0.73-1.42; P = .92). The increase in the hazards of overall mortality by nonpermissive HLA-DPB1 disparity was similar in 10 of 10 (HR = 2.12; CI, 1.23-3.64; P = .006) and 9 of 10 allele-matched transplantations (HR = 2.21; CI, 1.28-3.80; P = .004), both in early-stage and in advanced-stage disease. These data call for revisiting current HLA matching strategies for unrelated HSCT, suggesting that searches should be directed up-front toward identification of HLA-DPB1 permissive, 10 of 10 or 9 of 10 matched donors. (Blood. 2009; 114:1437-1444
Impact of nucleic acid testing for hepatitis B virus, hepatitis C virus, and human immunodeficiency virus on the safety of blood supply in Italy: A 6-year survey
BACKGROUND: Nucleic acid testing (NAT) for hepatitis C virus (HCV) and human immunodeficiency virus (HIV) has been implemented in several European countries and in the United States, while hepatitis B virus (HBV) NAT is still being questioned by opinions both in favor and against such an option, depending on the HBV endemicity, health care resources, and expected benefits. STUDY DESIGN AND METHODS: This survey was aimed to assess the NAT impact in improving the safety of blood supply in Italy, 6 years after implementation. The study involved 93 Italian transfusion centers and was carried out in 2001 through 2006. A total of 10,776,288 units were tested for the presence of HCV RNA, 7,932,430 for HIV RNA, and 3,405,497 for HBV DNA, respectively. RESULTS: Twenty-seven donations or 2.5 per million tested were HCV RNA-positive/anti-HCV-negative; 14 or 1.8 per million units tested were HIV RNA-positive/anti-HIV-negative; and 197 or 57.8 per million donations tested were HBV DNA-positive/hepatitis B surface antigen-negative. Of the latter, 8 (2.3/10(6)) were collected from donors in the window phase of infection and 189 (55.5/10(6)) from donors with occult HBV. Sixty-eight percent of the latter donors had hepatitis B surface antibody, 74.5 percent of whom with concentrations considered protective (>= 10 mIU/mL). CONCLUSION: NAT implementation has improved blood safety by reducing the risk of entering 2.5 HCV and 1.8 HIV infectious units per million donations into the blood supply. The yield of NAT in detecting infectious blood before transfusion was higher for HBV than for HCV or HIV. However, the benefit of HBV NAT in terms of avoided HBV-related morbidity and mortality in blood recipients needs to be further evaluated
