We present extensive datasets for a class of intermediate-luminosity optical transients known as luminous red novae. They show double-peaked light curves, with an initial rapid luminosity rise to a ...blue peak (at −13 to −15 mag), which is followed by a longer-duration red peak that sometimes is attenuated, resembling a plateau. The progenitors of three of them (NGC 4490−2011OT1, M 101−2015OT1, and SNhunt248), likely relatively massive blue to yellow stars, were also observed in a pre-eruptive stage when their luminosity was slowly increasing. Early spectra obtained during the first peak show a blue continuum with superposed prominent narrow Balmer lines, with P Cygni profiles. Lines of Fe II are also clearly observed, mostly in emission. During the second peak, the spectral continuum becomes much redder, Hα is barely detected, and a forest of narrow metal lines is observed in absorption. Very late-time spectra (∼6 months after blue peak) show an extremely red spectral continuum, peaking in the infrared (IR) domain. Hα is detected in pure emission at such late phases, along with broad absorption bands due to molecular overtones (such as TiO, VO). We discuss a few alternative scenarios for luminous red novae. Although major instabilities of single massive stars cannot be definitely ruled out, we favour a common envelope ejection in a close binary system, with possibly a final coalescence of the two stars. The similarity between luminous red novae and the outburst observed a few months before the explosion of the Type IIn SN 2011ht is also discussed.
Objective To evaluate mortality and morbidity in a large cohort of twin pregnancies according to chorionicity. We aimed to estimate the optimal time of delivery.
Design Historical cohort design.
...Setting Two teaching hospitals.
Population Twin pregnancies delivered in the University Medical Centre, Utrecht, and the St Elisabeth Hospital, Tilburg (1995–2004), The Netherlands (n = 1407).
Methods Pregnancy outcomes were documented according to chorionicity. Mortality ≥32 weeks was reviewed carefully with special attention to antenatal fetal monitoring, autopsy and placental histopathology to find an explanation for adverse outcome.
Main outcome measures Perinatal mortality and morbidity in monochorionic (MC) and dichorionic (DC) twins.
Results Perinatal mortality was 11.6% in MC twin pregnancies and 5.0% in DC twin pregnancies. After 32 weeks, the risk of intrauterine death (IUD) was significantly higher in MC twins than in DC twins (hazard ratio 8.8, 95% CI 2.7–28.9). In most of these cases of IUD, no antenatal signs of impaired fetal condition had been present. Median gestational age was 1 week longer in DC twins than in MC twins, and the mean birthweight was 221 g higher. Severe birthweight discordancy (>20%) occurred more often in MC twins than in DC twins (OR 1.23, 95% CI 0.97–1.55). The incidence of necrotising enterocolitis (NEC) was higher in MC twins, after adjustment for age and weight at birth (OR 4.05, 95% CI 1.97–8.35). There was a trend towards higher neuromorbidity in MC twins.
Conclusions This is the largest cohort study of twin pregnancies evaluating outcome according to chorionicity thus far. MC twins are at increased risk for fetal death (even at term), NEC and neuromorbidity. Current antenatal care is insufficient to predict and prevent this excess perinatal mortality and morbidity. Planned delivery at or even before 37 weeks of gestation seems to be justified for MC twins.
The Two Micron All Sky Survey (2MASS) Skrutskie, M. F; Cutri, R. M; Stiening, R ...
The Astronomical journal,
02/2006, Letnik:
131, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Between 1997 June and 2001 February the Two Micron All Sky Survey (2MASS) collected 25.4 Tbytes of raw imaging data covering 99.998% of the celestial sphere in the near-infrared J (1.25 mm), H (1.65 ...mm), and Ks (2.16 mm) bandpasses. Observations were conducted from two dedicated 1.3 m diameter telescopes located at Mount Hopkins, Arizona, and Cerro Tololo, Chile. The 7.8 s of integration time accumulated for each point on the sky and strict quality control yielded a 10 s point-source detection level of better than 15.8, 15.1, and 14.3 mag at the J, H, and Ks bands, respectively, for virtually the entire sky. Bright source extractions have 1 s photometric uncertainty of <0.03 mag and astrometric accuracy of order 100 mas. Calibration offsets between any two points in the sky are <0.02 mag. The 2MASS All-Sky Data Release includes 4.1 million compressed FITS images covering the entire sky, 471 million source extractions in a Point Source Catalog, and 1.6 million objects identified as extended in an Extended Source Catalog.
Loeys-Dietz syndrome (LDS) associates with a tissue signature for high transforming growth factor (TGF)-β signaling but is often caused by heterozygous mutations in genes encoding positive effectors ...of TGF-β signaling, including either subunit of the TGF-β receptor or SMAD3, thereby engendering controversy regarding the mechanism of disease. Here, we report heterozygous mutations or deletions in the gene encoding the TGF-β2 ligand for a phenotype within the LDS spectrum and show upregulation of TGF-β signaling in aortic tissue from affected individuals. Furthermore, haploinsufficient Tgfb2(+/-) mice have aortic root aneurysm and biochemical evidence of increased canonical and noncanonical TGF-β signaling. Mice that harbor both a mutant Marfan syndrome (MFS) allele (Fbn1(C1039G/+)) and Tgfb2 haploinsufficiency show increased TGF-β signaling and phenotypic worsening in association with normalization of TGF-β2 expression and high expression of TGF-β1. Taken together, these data support the hypothesis that compensatory autocrine and/or paracrine events contribute to the pathogenesis of TGF-β-mediated vasculopathies.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
There is a growing need for techniques that can identify and characterize protein modifications on a large or global scale. We report here a proteomics approach to enrich, recover, and identify ...ubiquitin conjugates from Saccharomyces cerevisiae lysate. Ubiquitin conjugates from a strain expressing 6xHis-tagged ubiquitin were isolated, proteolyzed with trypsin and analyzed by multidimensional liquid chromatography coupled with tandem mass spectrometry (LC/LC-MS/MS) for amino acid sequence determination. We identified 1,075 proteins from the sample. In addition, we detected 110 precise ubiquitination sites present in 72 ubiquitin-protein conjugates. Finally, ubiquitin itself was found to be modified at seven lysine residues providing evidence for unexpected diversity in polyubiquitin chain topology in vivo. The methodology described here provides a general tool for the large-scale analysis and characterization of protein ubiquitination.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Introduction
It is unclear if the collar and cuff treatment improve alignment in displaced surgical neck fractures of the proximal humerus. Therefore, this study evaluated if the neckshaft angle and ...extent of displacement would improve between trauma and onset of radiographically visible callus in non-operatively treated surgical neck fractures (Boileau type A, B, C).
Materials and Methods
A consecutive series of patients (≥ 18 years old) were retrospectively evaluated from a level 1 trauma center in Australia (inclusion period: 2016–2020) and a level 2 trauma center in the Netherlands (inclusion period: 2004 to 2018). Patients were included if they sustained a Boileau-type fracture and underwent initial non-operative treatment. The first radiograph had to be obtained within 24 h after the initial injury and the follow-up radiograph(s) 1 week after trauma and before the start of radiographically visible callus. On each radiograph, the maximal medial gap (MMG), maximal lateral gap (MLG), and neck-shaft angle (NSA) were measured. Linear mixed modelling was performed to evaluate if these measurements would improve over time.
Results
Sixty-seven patients were included: 25 type A, 11 type B, and 31 type C fractures.
The mean age (range) was 68 years (24–93), and the mean number (range) of follow-up radiographs per patient was 1 (1–4). Linear mixed modelling on both MMG and MLG revealed no improvement during follow-up among the three groups. Mean NSA of type A fractures improved significantly from 161° at trauma to 152° at last follow-up (
p-
value = 0.004).
Conclusions
Apart from humeral head angulation improvement in type A, there is no increase nor reduction in displacement among the three fracture patterns. Therefore, it is advised that surgical decision-making should be performed immediately after trauma.
Level of clinical evidence
Level IV, retrospective case series.
Genes involved in fatty acid catabolism have undergone extensive duplication in the genus Mycobacterium, which includes the etiologic agents of leprosy and tuberculosis. Here, we show that ...prokaryotic- and eukaryotic-like isoforms of the glyoxylate cycle enzyme isocitrate lyase (ICL) are jointly required for fatty acid catabolism and virulence in Mycobacterium tuberculosis. Although deletion of icl1 or icl2, the genes that encode ICL1 and ICL2, respectively, had little effect on bacterial growth in macrophages and mice, deletion of both genes resulted in complete impairment of intracellular replication and rapid elimination from the lungs. The feasibility of targeting ICL1 and ICL2 for chemical inhibition was shown using a dual-specific ICL inhibitor, which blocked growth of M. tuberculosis on fatty acids and in macrophages. The absence of ICL orthologs in mammals should facilitate the development of glyoxylate cycle inhibitors as new drugs for the treatment of tuberculosis.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Abstract
Supernova (SN) 2016bdu is an unusual transient resembling SN 2009ip. SN 2009ip-like events are characterized by a long-lasting phase of erratic variability that ends with two luminous ...outbursts a few weeks apart. The second outburst is significantly more luminous (about 3 mag) than the first. In the case of SN 2016bdu, the first outburst (Event A) reached an absolute magnitude Mr ≈ −15.3 mag, while the second one (Event B) occurred over one month later and reached Mr ≈ −18 mag. By inspecting archival data, a faint source at the position of SN 2016bdu is several times in the past few years. We interpret these detections as signatures of a phase of erratic variability, similar to that experienced by SN 2009ip between 2008 and mid-2012, and resembling the currently observed variability of the luminous blue variable SN 2000ch in NGC 3432. Spectroscopic monitoring of SN 2016bdu during the second peak initially shows features typical of an SN IIn. One month after the Event B maximum, the spectra develop broad Balmer lines with P Cygni profiles and broad metal features. At these late phases, the spectra resemble those of a typical Type II SN. All members of this SN 2009ip-like group are remarkably similar to the Type IIn SN 2005gl. For this object, the claim of a terminal SN explosion is supported by the disappearance of the progenitor star. While the similarity with SN 2005gl supports a genuine SN explosion scenario for SN 2009ip-like events, the unequivocal detection of nucleosynthesized elements in their nebular spectra is still missing.
Mycobacterium tuberculosis claims more human lives each year than
any other bacterial pathogen. Infection is maintained in spite of acquired
immunity and resists eradication by antimicrobials. ...Despite
an urgent need for new therapies targeting persistent bacteria, our knowledge
of bacterial metabolism throughout the course of infection remains rudimentary.
Here we report that persistence of M. tuberculosis in mice is facilitated
by isocitrate lyase (ICL), an enzyme essential for the metabolism of fatty
acids. Disruption of the icl gene attenuated bacterial
persistence and virulence in immune-competent mice without affecting bacterial
growth during the acute phase of infection. A link between the requirement
for ICL and the immune status of the host was established by the restored
virulence of Δicl bacteria in interferon-γ knockout mice.
This link was apparent at the level of the infected macrophage: Activation
of infected macrophages increased expression of ICL, and the Δicl
mutant was markedly attenuated for survival in activated but not resting
macrophages. These data suggest that the metabolism of M. tuberculosis
in vivo is profoundly influenced by the host response to infection,
an observation with important implications for the treatment of chronic tuberculosis.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Genomic technologies have significantly advanced our understanding of the composition and diversity of host-associated microbial populations. However, their spatial organization and functional ...interactions relative to the host have been more challenging to study. Here we present a pipeline for the assessment of intestinal microbiota localization within immunofluorescence images of fixed gut cross-sections that includes a flexible software package, BacSpace, for high-throughput quantification of microbial organization. Applying this pipeline to gnotobiotic and human microbiota-colonized mice, we demonstrate that elimination of microbiota-accessible carbohydrates (MACs) from the diet results in thinner mucus in the distal colon, increased proximity of microbes to the epithelium, and heightened expression of the inflammatory marker REG3β. Measurements of microbe-microbe proximity reveal that a MAC-deficient diet alters monophyletic spatial clustering. Furthermore, we quantify the invasion of Helicobacter pylori into the glands of the mouse stomach relative to host mitotic progenitor cells, illustrating the generalizability of this approach.
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•Single-cell imaging at tissue scales reveals spatial organization of gut microbiota•Absence of dietary fiber drives thinning of protective mucus layer•Microbe-microbe proximity measurement reveals monophyletic clustering is diet-dependent•BacSpace software enables large-scale quantitative image analysis
Earle et al. combine imaging methods with analysis software to enable high-resolution quantification of gut microbiota spatial organization in tissues. Their analysis reveals that elimination of microbiota-accessible carbohydrates from the diet results in thinner mucus, increased proximity of microbes to the epithelium, and heightened expression of inflammatory markers.
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