356 research outputs found
Protostellar jets: a statistical view with the CALYPSO IRAM-PdBI survey
Interstellar matter and star formatio
Thrombospondin modulates melanoma--platelet interactions and melanoma tumour cell growth in vivo.
In this study we have investigated the role of thrombospondin (TSP) as a possible ligand playing a key role in human M3Da. melanoma cell interaction with platelets and in tumour growth. TSP is secreted (80 +/- 6 ng TSP 10(-6) cells) and bound to the surface of M3Da. cells via receptors different from CD36, as shown by biosynthetic labelling and immunofluorescence studies. The levels of TSP binding to M3Da. cells evaluated by binding studies, using an anti-TSP monoclonal antibody (MAb) (LYP8), shows 367,000 +/- 58,000 (mean +/- s.d.) LYP8 binding sites per cell with a dissociation constant (Kd) of 67 nM. TSP binding to M3Da. cells shows 400,000 +/- 50,000 TSP binding sites per cell with a Kd of 10 nM. The capacity of anti-TSP MAb (LYP8) to inhibit M3Da.-platelet interactions was followed on an aggregometer and evaluated by electron microscopy studies. The biological role of TSP binding to M3Da. cells was investigated by implanting subcutaneously the M3Da. cell line in nude mice and following the size and time of in vivo tumour growth. Reducing the availability or the functional level of TSP by using an anti-TSP MAb (LYP8) resulted in a significant decrease in platelet aggregates interacting with M3Da. melanoma cells. Using an enzyme-linked immunosorbent assay, purified alpha nu beta 3 was shown to bind TSP. Moreover, LYP8-coated M3Da. cells showed a reduced capacity to form tumours in vivo. M3Da. cells were observed to attach and spread on human platelet TSP-coated plastic wells. This attachment by M3Da. cells was inhibited in a similar way by LYP8 and an anti-alpha nu beta 3 MAb (LYP18). The results obtained in this study show that TSP secreted and bound to the surface of a human melanoma cell line (M3Da.) acts as a link between aggregated platelets and the M3Da. cell surface. Moreover, these results shows that TSP can modulate tumour growth in vivo. Reagents such as MAbs directed against TSP and peptides derived from TSP could not only be used as a new therapeutic approach in the control of tumour metastasis of melanoma, but may also contribute to elucidation of the role of TSP in cancer biology
Effect of MHD wind-driven disk evolution on the observed sizes of protoplanetary disks
Stars and planetary system
Evidence for ubiquitous carbon grain destruction in hot protostellar envelopes
Earth is deficient in carbon and nitrogen by up to orders of
magnitude compared with the Sun. Destruction of (carbon- and nitrogen-rich)
refractory organics in the high-temperature planet forming regions could
explain this deficiency. Assuming a refractory cometary composition for these
grains, their destruction enhances nitrogen-containing oxygen-poor molecules in
the hot gas (K) after the initial formation and sublimation of
these molecules from oxygen-rich ices in the warm gas (K). Using
observations of high-mass protostars with ALMA, we find that
oxygen-containing molecules (CHOH and HNCO) systematically show no
enhancement in their hot component. In contrast, nitrogen-containing,
oxygen-poor molecules (CHCN and CHCN) systematically show an
enhancement of a factor in their hot component, pointing to
additional production of these molecules in the hot gas. Assuming only thermal
excitation conditions, we interpret these results as a signature of destruction
of refractory organics, consistent with the cometary composition. This
destruction implies a higher C/O and N/O in the hot gas than the warm gas,
while, the exact values of these ratios depend on the fraction of grains that
are effectively destroyed. This fraction can be found by future chemical models
that constrain C/O and N/O from the abundances of minor carbon, nitrogen and
oxygen carriers presented here.Comment: Accepted for publication in ApJ Letter
Bariatric Surgery Outcomes in Appalachia Influenced by Surgery Type, Diabetes, and Depression
Background
Most effective treatment for morbid obesity and its comorbidities is bariatric surgery. However, research is limited on weight loss and associated outcomes among patients in Appalachia. The objective of this study was to examine demographic and comorbidity influence on surgical outcomes of this population including age, sex, race, state of residence, education, marital status, body mass index (BMI kg/m2), excess body weight (EBW), percent excess weight loss (%EWL), blood pressure, diagnosed depression, diagnosed type 2 diabetes (T2D), Beck Depression Inventory-II (BDI-II), and laboratory values (i.e., hemoglobin A1c). Methods
A retrospective electronic medical record (EMR) data extraction was performed on N = 582 patients receiving bariatric surgery (laparoscopic Roux-en-Y gastric bypass [RYGB] and laparoscopic sleeve gastrectomy [SG]) between 10/2013 and 2/2017. Results
Patient population was 92.5% Caucasian, 79.3% female, 62.8% married, 45 ± 11.1 years, 75.8% received RYGB, and 24.2% received SG. Average %EWL from baseline to 1-year follow-up was 68.5 ± 18.4% (n = 224). In final descriptive models, surgery type, diagnosed T2D, HbA1c, and depressive symptoms were significant covariates associated with lower %EWL. Conclusions
Findings suggest patients completing surgery within an Appalachian region have successful surgical outcomes at 1-year post-surgery, as indicated by significant reductions of \u3e 50% EWL, regardless of other covariates. Results suggest that bariatric programs should consider paying special consideration to patients with T2D or depressive symptoms to improve outcomes. Results have potential to inform future prospective studies and aid in guiding specific interventions tailored to address needs of this unique population
Prostate-Specific Antigen testing in men between 40 and 70 years in Brazil: database from a check-up program
Objectives To evaluate the PSA in a large population of Brazilian men undergone to check up, and correlate the PSA cutoffs with prostate size and urinary symptoms. Materials and Methods This is a cross sectional study performed with men between 40 and 70 years undergone to check-up. All men were undergone to urological evaluation, digital rectal examination, prostate-specific antigen, and ultrasonography The exclusion criteria were men who used testosterone in the last six months, or who were using 5 alpha-reductase inhibitors. Results A total of 5015 men with an average age of 49.0 years completed the study. Most men were white and asymptomatic. The PSA in the three different aging groups were 0.9 ± 0.7ng/dL for men between 40 and 50; 1.2 ± 0.5ng/dL for men between 50 and 60; and 1.7 ± 1.5ng/dL for men greater than 60 years (p=0.001). A total of 192 men had PSA between 2.5 and 4ng/ml. From these men 130 were undergone to prostate biopsy. The predictive positive value of biopsy was 25% (32/130). In the same way, 100 patients had PSA >4ng/mL. From these men, 80 were undergone to prostate biopsy. In this group, the predictive positive value of biopsy was 40% (32/100). The Gleason score was 6 in 19 men (60%), 7 in 10 men (31%) and 8 in 3 men (9%). Conclusions The PSA level of Brazilian men undergone to check up was low. There was a positive correlation with aging, IPSS and prostate size.Universidade Federal de São Paulo (UNIFESP) Department of UrologyHospital Israelita Albert EinsteinWake Forest UniversityUNIFESP, Department of UrologySciEL
Fire Affects Ecophysiology and Community Dynamics of Central Wisconsin Oak Forest Regeneration
In order to understand better the ecophysiological differences among competing species that might influence competitive interactions after, or in the absence of, fire, we examined the response to fire of four sympatric woody species found in intermediatesized gaps in a 30-yr-old mixed-oak forest in central Wisconsin. Selected blocks in the forest were burned in April 1987 by a low-intensity controlled surface fire. The fire had significant effects during the following growing season on community structure, foliar nutrient concentrations, and photosynthesis. Acer rubrum seedling density declined by 70%
following the fire, while percent cover increased several-fold in Rubus allegheniensis. In general, leaf concentrations of N, P, and K were increased by the fire in all species, although the relative enhancement decreased as the growing season progressed. Daily maximum photosynthetic rates were 30-50% higher in burned than unburned sites for Prunus serotina,
Quercus ellipsoidalis, and R. allegheniensis, but did not differ between treatments for A. rubrum. Mean sunlit photosynthetic rates and leaf conductances were stimulated by the burn for all species, with the greatest enhancement in photosynthesis measured in Q. ellipsoidalis. Leaf gas exchange in R. allegheniensis was most sensitive to declining leaf
water potential and elevated vapor pressure gradient, with Q. ellipsoidalis the least sensitive. Fire had no discernable effect on water status of these plants during a year of relatively high rainfall. In comparison with other species, A. rubrum seedlings responded negatively after fire-both in terms of survival/reproduction (decline in the number of individuals)
and relative leaf physiological performance. Fire enhanced the abundance of R. allegheniensis and the potential photosynthetic performance of R. allegheniensis, P. serotina, and particularly Q. ellipsoidalis. We conclude that post-fire stimulation of net photosynthesis and conductance was largely the result of enhanced leaf N concentrations in these species
The diverse chemistry of protoplanetary disks as revealed by JWST
Early results from the JWST-MIRI guaranteed time programs on protostars
(JOYS) and disks (MINDS) are presented. Thanks to the increased sensitivity,
spectral and spatial resolution of the MIRI spectrometer, the chemical
inventory of the planet-forming zones in disks can be investigated with
unprecedented detail across stellar mass range and age. Here data are presented
for five disks, four around low-mass stars and one around a very young
high-mass star. The mid-infrared spectra show some similarities but also
significant diversity: some sources are rich in CO2, others in H2O or C2H2. In
one disk around a very low-mass star, booming C2H2 emission provides evidence
for a ``soot'' line at which carbon grains are eroded and sublimated, leading
to a rich hydrocarbon chemistry in which even di-acetylene (C4H2) and benzene
(C6H6) are detected (Tabone et al. 2023). Together, the data point to an active
inner disk gas-phase chemistry that is closely linked to the physical structure
(temperature, snowlines, presence of cavities and dust traps) of the entire
disk and which may result in varying CO2/H2O abundances and high C/O ratios >1
in some cases. Ultimately, this diversity in disk chemistry will also be
reflected in the diversity of the chemical composition of exoplanets.Comment: 17 pages, 8 figures. Author's version of paper submitted to Faraday
Discussions January 18 2023, Accepted March 16 202
Complex organic molecules in low-mass protostars on Solar System scales -- II. Nitrogen-bearing species
The chemical inventory of planets is determined by the physical and chemical
processes that govern the early phases of star formation. The aim is to
investigate N-bearing complex organic molecules towards two Class 0 protostars
(B1-c and S68N) at millimetre wavelengths with ALMA. Next, the results of the
detected N-bearing species are compared with those of O-bearing species for the
same and other sources. ALMA observations in Band 6 ( 1 mm) and Band 5
( 2 mm) are studied at 0.5" resolution, complemented by Band 3
( 3 mm) data in a 2.5" beam. NH2CHO, C2H5CN, HNCO, HN13CO, DNCO,
CH3CN, CH2DCN, and CHD2CN are identified towards the investigated sources.
Their abundances relative to CH3OH and HNCO are similar for the two sources,
with column densities that are typically an order of magnitude lower than those
of O-bearing species. The largest variations, of an order of magnitude, are
seen for NH2CHO abundance ratios with respect to HNCO and CH3OH and do not
correlate with the protostellar luminosity. In addition, within uncertainties,
the N-bearing species have similar excitation temperatures to those of
O-bearing species ( 100 300 K). The similarity of most abundances
with respect to HNCO, including those of CH2DCN and CHD2CN, hints at a shared
chemical history, especially the high D/H ratio in cold regions prior to star
formation. However, some of the variations in abundances may reflect the
sensitivity of the chemistry to local conditions such as temperature (e.g.
NH2CHO), while others may arise from differences in the emitting areas of the
molecules linked to their different binding energies in the ice. The two
sources discussed here add to the small number of sources with such a detailed
chemical analysis on Solar System scales. Future JWST data will allow a direct
comparison between the ice and gas abundances of N-bearing species.Comment: Accepted to A&A, 41 pages, 37 figure
Mouse transcriptome reveals potential signatures of protection and pathogenesis in human tuberculosis
Although mouse infection models have been extensively used to study the host response to Mycobacterium tuberculosis, their validity in revealing determinants of human tuberculosis (TB) resistance and disease progression has been heavily debated. Here, we show that the modular transcriptional signature in the blood of susceptible mice infected with a clinical isolate of M. tuberculosis resembles that of active human TB disease, with dominance of a type I interferon response and neutrophil activation and recruitment, together with a loss in B lymphocyte, natural killer and T cell effector responses. In addition, resistant but not susceptible strains of mice show increased lung B cell, natural killer and T cell effector responses in the lung upon infection. Notably, the blood signature of active disease shared by mice and humans is also evident in latent TB progressors before diagnosis, suggesting that these responses both predict and contribute to the pathogenesis of progressive M. tuberculosis infection
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