Context.
We present a systematic X-ray spectral-timing study of the recently discovered, exceptionally bright black hole X-ray binary system MAXI J1820+070. Our analysis focuses on the first part of ...the 2018 outburst, covering the rise throughout the hard state, the bright hard and hard-intermediate states, and the transition to the soft-intermediate state.
Aims.
We address the issue of constraining the geometry of the innermost accretion flow and its evolution throughout an outburst.
Methods.
We employed two independent X-ray spectral-timing methods applied to archival NICER data of MAXI J1820+070. We first identified and tracked the evolution of a characteristic frequency of soft X-ray thermal reverberation lags (lags of the thermally reprocessed disc emission after the irradiation of variable hard X-ray photons). This frequency is sensitive to intrinsic changes in the relative distance between the X-ray source and the disc. Then, we studied the spectral evolution of the quasi-thermal component responsible for the observed thermal reverberation lags. We did so by analysing high-frequency covariance spectra, which single out spectral components that vary in a linearly correlated way on the shortest sampled timescales and are thus produced in the innermost regions of the accretion flow.
Results.
The frequency of thermal reverberation lags steadily increases throughout most of the outburst, implying that the relative distance between the X-ray source and the disc decreases as the source softens. However, near transition this evolution breaks, showing a sudden increase (decrease) in lag amplitude (frequency). On the other hand, the temperature of the quasi-thermal component in covariance spectra, due to disc irradiation and responsible for the observed soft reverberation lags, consistently increases throughout all the analysed observations.
Conclusions.
This study proposes an alternative interpretation to the recently proposed contracting corona scenario. Assuming a constant height for the X-ray source, the steady increase in the reverberation lag frequency and in the irradiated disc temperature in high-frequency covariance spectra can be explained in terms of a decrease in the disc inner radius as the source softens. The behaviour of thermal reverberation lags near transition might be related to the relativistic plasma ejections detected at radio wavelengths, suggesting a causal connection between the two phenomena. Throughout most of the hard and hard-intermediate state, the disc is consistent with being truncated (with an inner radius
R
in
≳ 10
R
g
), reaching close to the innermost stable circular orbit only near transition.
Carbapenem-resistant Enterobacteriaceae represents a major public health issue. This study investigated the clonality and resistance mechanisms of 92 carbapenem-resistant
E. coli
(
n =
21) and
K. ...pneumoniae
(
n =
71) isolates collected consecutively from clinical specimens and patients at high risk of carriage between 2010 and 2012 in a healthcare region in Hong Kong. Combined disk tests (CDTs) and the Carba NP test were used for phenotypic detection of carbapenemases. PCR assays were used to detect carbapenemase genes. All isolates were intermediate or resistant to at least one carbapenem. Nine (9.8 %) isolates were genotypic carbapenemase producers and included six
K. pneumoniae
(one ST1306/
bla
IMP-4
, one ST889/
bla
IMP-4
, two ST11/
bla
KPC-2
, one ST258/
bla
KPC-2
, one ST483/
bla
NDM-1
) and three
E. coli
(one ST131/
bla
IMP-4
, two ST744/
bla
NDM-1
) isolates. All nine isolates carrying carbapenemase genes could be detected by the CDTs and the Carba NP test. PCR identified
bla
CTX-M
and
bla
AmpC
alone or in combination in 77.8 % (7/9) and 96.4 % (80/83) of the carbapenemase-producers and non-producers, respectively. Porin loss was detected in 22.2 % (2/9) and 59.0 % (49/83) of the carbapenemase-producers and non-producers, respectively. Overall, the
E. coli
clones were diverse (14 different STs), but 36.6 % (26/71) of the
K. pneumoniae
isolates belonged to ST11. In conclusion, the prevalence of carbapenemases among carbapenem-nonsusceptible
E. coli
and
K. pneumoniae
remained low in Hong Kong. Porin loss combined with AmpC and/or CTX-M type ESBL was the major mechanism of carbapenem resistance in the study population.
Objectives
We examined the relationship between absolute income, adequacy of disposable income, and self-rated health among participants aged 60 years and over.
Design
Cross sectional study.
Setting
...Community living older people in Hong Kong.
Participants
Older people aged 60 years and over in five districts in Hong Kong.
Measurements
Data from a cross sectional survey of age friendly characteristics across five districts of Hong Kong carried out using stratified random sampling across a broad range of socioeconomic attributes.
Results
Self-rated health showed a gradient for both absolute and adequacy of disposable income. The OR for the association between having just enough, or insufficient disposable income and poor health was higher: 2.0 and 3.6 respectively, and higher than that for absolute income (OR 1.8), and remained significant after adjustment for absolute income. No association between absolute income and self-rated health was observed among women. These findings suggest that adequacy of disposable income provide a stronger association with self-rated health compared with absolute income among older people aged 60 years and over, particularly for women. The absolute income corresponding to what is considered adequate disposable income lies between HK$4000–10000.
Conclusion
Adequacy of disposable income may be a better indicator than absolute income for older people in examining the relationship with health outcomes, particularly for older women.
Aim
To assess the connection between mitophagy and hypoxia‐induced apoptosis in osteoblasts and whether simvastatin alleviates bone resorption in apical periodontitis through modulation of ...mitophagy‐related apoptosis.
Methodology
Hypoxia‐induced generation of reactive oxygen species in mitochondria and changes in mitochondrial membrane potential were evaluated, respectively, by MitoSOX and JC‐1 fluorescence dye signalling. Accumulation of mitophagy markers PTEN‐induced putative kinase 1 (PINK1) and Parkin in mitochondria was examined by Western blotting and immunofluorescence microscopy. Osteoblast apoptosis was assessed by Western analysis of cleaved‐poly (adenosine diphosphate ribose) polymerase (PARP). In a rat model of induced apical periodontitis, the therapeutic effect of simvastatin and its action on osteoblast mitophagy and apoptosis were examined. anova, Fisher's and Student's t‐test were used for data analysis.
Results
Hypoxia‐induced mitochondrial dysfunction and stimulated mitophagy in osteoblasts. Hypoxia also provoked apoptosis in osteoblasts and inhibition of mitophagy decreased hypoxia‐augmented apoptotic activity. Simvastatin alleviated hypoxia‐induced mitochondrial dysfunction, mitophagy and apoptosis. The protective action of simvastatin against apoptosis was related to its antimitophagy activity. Experiments in the rat model of induced apical periodontitis supported the laboratory findings. Simvastatin treatment mitigated periapical bone loss and reduced the activities of apoptosis and mitophagy in regional osteoblasts.
Conclusions
The results suggest that modulation of osteoblast mitophagy may help diminish bone loss associated with inflammation and has potential as an auxiliary therapy for apical periodontitis.
Irisin in domestic animals Lai, E.; Unniappan, S.
Domestic animal endocrinology,
April 2023, 2023-04-00, 20230401, Letnik:
83
Journal Article
Recenzirano
•Irisin is a highly conserved peptide in domestic animals.•Irisin is abundant in many tissues in animals.•Irisin has the potential to be used as a biomarker and therapeutic agent.
Irisin is a 112 ...amino acid peptide hormone cleaved from the fibronectin type III domain-containing protein. Irisin is highly conserved across vertebrates, suggesting evolutionarily conserved common functions among domestic animals. These functions include the browning of white adipose tissue and increased energy expenditure. Irisin has been detected and studied primarily in plasma, serum, and skeletal muscle, but has also been found in adipose tissue, liver, kidney, lungs, cerebrospinal fluid, breast milk, and saliva. This wider tissue presence of irisin suggests additional functions beyond its role as a myokine in regulating energy use. We are beginning to understand irisin in domestic animals. The goal of this review is to provide an up-to-date commentary on irisin structure, tissue distribution, and functions across vertebrates, especially mammals of importance in veterinary medicine. Irisin could be explored as a potential candidate for developing therapeutic agents and biomarkers in domestic animal endocrinology.
A high rate of suicide has been reported in patients who sustain fractures, but the association remains uncertain in the context of other factors. The aim of this study was to examine the association ...between fractures and the risk of suicide in this contextual setting.
We performed a case-control study of patients aged 40 years or older who died by suicide between 2000 and 2011. We included patients' demographics, physical and mental health problems, and socioeconomic factors. We performed conditional logistic regression to evaluate the associations between fractures and the risk of suicide.
We included a total of 34 794 patients who died by suicide and 139 176 control patients. We found that fractures as a homogenous group (adjusted odds ratios (aOR), 1.48; 95% confidence interval (CI) 1.43 to 1.53), and specifically pelvic (aOR 2.04; 95% CI 1.68 to 2.47) and spinal fractures (aOR 1.53; 95% CI 1.43 to 1.64), were associated with a higher risk of suicide. In addition, we found that patients who had a lower income, had never married, had lower levels of educational attainment, or had coexistent physical and mental conditions such as anxiety, mood disorders, and psychosis-related disorders had a higher risk of suicide.
Fractures, specifically those of the hip and spine, were associated with an increased risk of suicide. The findings suggest that greater clinical attention should be given to this risk in patients with fractures, especially for those with additional risk factors. Cite this article: Bone Joint J 2018;100-B:780-6.
Irisin is a 112-amino acid peptide hormone that is cleaved from fibronectin type III domain-containing protein 5 (FNDC5), a type I transmembrane protein abundantly found in muscle tissue. Irisin is a ...putative mediator of the benefits of exercise, neuroprotection, bone growth, and cardiac health. However, few studies have focused on irisin in domestic animals. Further, whether processed irisin is detectable in domestic animal tissues remains uncertain. To address this, we determined FNDC5 mRNA and protein concentration in anatine (duck) and porcine (pig) skeletal muscle, and in equine (horse), swine, and anatine serum samples. RT-PCR analysis identified FNDC5 mRNA in all pig and duck skeletal muscle samples. An approximately 25 kDa band representing FNDC5 was detected in both pig and duck skeletal muscle. Fluorescence immunohistochemistry using a rabbit monoclonal FNDC5/irisin primary antibody and a goat polyclonal anti-rabbit secondary antibody localized FNDC5/irisin-like immunoreactivity in both the glandular and muscular regions of pig stomach. FNDC5/irisin-like immunoreactivity was also identified in horse, pig, and duck serum using a multispecies irisin ELISA. The average values of irisin-like immunoreactivity were 13.7 (duck), 15.4 (horse), and 7.0 (pig) ng/mL in samples tested. Our results support the presence of irisin precursor in several domestic animals. Processed irisin, however, was not detectable. Further studies are required to validate reliable tools to detect and quantify processed irisin in domestic animals.
•FNDC5 mRNA was detected in duck and pig skeletal muscle.•While FNDC5 precursor was detectable in pig and duck muscle, processed irisin was not.•FNDC5-like immunoreactivity was detected in serum of domestic animals.•Non-specificity exists in commercially available FNDC5 antibodies.
The Fracture Risk Assessment Tool (FRAX) has been used universally for the purpose of fracture risk assessment. However, the predictive capacity of FRAX for autoimmune diseases remains inconclusive. ...This study aimed to compare the applicability of FRAX for autoimmune disease patients. This retrospective study recruited rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and primary Sjögren syndrome (pSS) patients with bone mineral density (BMD) tests. Patients with any osteoporotic fractures were identified. Taiwan-specific FRAX with and without BMD were then calculated. In total, 802 patients (451 RA, 233 SLE and 118 pSS) were enrolled in this study. The cumulative incidences of osteoporotic fractures in the RA, SLE and pSS patients were 43.0%, 29.2% and 33.1%, respectively. For those with a previous osteoporotic fracture, T-scores were classified as low bone mass. Overall, the patients’ 10-year probability of major fracture risk by FRAX without BMD was 15.8%, which then increased to 20.3% after incorporation of BMD measurement. When analyzed by disease group, the fracture risk in RA patients was accurately predicted by FRAX. In contrast, current FRAX, either with or without BMD measurement, underestimated the fracture risk both in SLE and pSS patients, even after stratification by age and glucocorticoid treatment. For pSS patients with major osteoporotic fractures, FRAX risks imputed by RA were comparable to major osteoporotic fracture risks of RA patients. Current FRAX accurately predicted fracture probability in RA patients, but not in SLE and pSS patients. RA-imputed FRAX risk scores could be used as a temporary substitute for SLE and pSS patients.
Notch is a transmembrane receptor that mediates local cell-cell communication and coordinates a signaling cascade present in all animal species studied to date. Notch signaling is used widely to ...determine cell fates and to regulate pattern formation; its dysfunction results in a tremendous variety of developmental defects and adult pathologies. This primer describes the mechanism of Notch signal transduction and how it is used to control the formation of biological patterns.
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