2,664 research outputs found
Proteomic profiling of stallion spermatozoa suggests changes in sperm metabolism and compromised redox regulation after cryopreservation
Proteomic technologies allow the detection of thousands of proteins at the same time, being a powerful technique to reveal molecular regulatory mechanisms in spermatozoa and also sperm damage linked to low fertility or specific biotechnologies. Modifications induced by the cryopreservation in the stallion sperm proteome were studied using UHPLC/MS/MS. Ejaculates from fertile stallions were collected and split in two subsamples, one was investigated as fresh (control) samples, and the other aliquot frozen and thawed using standard procedures and investigated as frozen thawed subsamples. UHPLC/MS/MS was used to study the sperm proteome under these two distinct conditions and bioinformatic enrichment analysis conducted. Gene Ontology (GO) and pathway enrichment analysis were performed revealing dramatic changes as consequence of cryopreservation. The terms oxidative phosphorylation, mitochondrial ATP synthesis coupled electron transport and electron transport chain were significantly enriched in fresh samples (P = 5.50 × 10−12, 4.26 × 10−8 and 7.26 × 10–8, respectively), while were not significantly enriched in frozen thawed samples (P = 1). The GO terms oxidation reduction process and oxidoreductase activity were enriched in fresh samples and the enrichment was reduced in frozen thawed samples (1.40 × 10−8, 1.69 × 10−6 versus 1.13 × 10−2 and 2-86 × 10−2 respectively). Reactome pathways (using human orthologs) significantly enriched in fresh sperm were TCA cycle and respiratory electron transport (P = 1.867 × 10−8), Respiratory electron transport ATP synthesis by chemiosmosis coupling (P = 2.124 × 10−5), Citric acid cycle (TCA cycle)(P = 8.395 × 10−4) Pyruvate metabolism and TCA cycle (P = 3.380 × 10−3), Respiratory electron transport (P = 2.764 × 10−2) and Beta oxidation of laurolyl-CoA to decanoyl CoA-CoA (P = 1.854 × 10−2) none of these pathways were enriched in thawed samples (P = 1). We have provided the first detailed study on how the cryopreservation process impacts the stallion sperm proteome. Our findings identify the metabolic proteome and redoxome as the two key groups of proteins affected by the procedure. Significance: In the present manuscript we investigated how the cryopreservation of stallion spermatozoa impacts the proteome of these cells. This procedure is routinely used in horse breeding and has a major impact in the industry, facilitating the trade of genetic material. This is still a suboptimal biotechnology, with numerous unresolved problems. The limited knowledge of the molecular insults occurring during cryopreservation is behind these problems. The application and development of proteomics to the spermatozoa, allow to obtain valuable information of the specific mechanisms affected by the procedure. In this paper, we report that cryopreservation impacts numerous proteins involved in metabolism regulation (mainly mitochondrial proteins involved in the TCA cycle, and oxidative phosphorylation) and also affects proteins with oxidoreductase activity. Moreover, specific proteins involved in the sperm-oocyte interaction are also affected by the procedure. The information gathered in this study, opens interesting questions and offer new lines of research for the improvement of the technology focusing the targets here identified, and the specific steps in the procedure (cooling, toxicity of antioxidants etc.) to be modified to reduce the damage
Lightning Impulse Current Tests on Conductive Fabrics
Submitted to "Journal of Industrial Textiles"The large amount of electric current associated to lightning discharges is hazardous for living beings, equipment, structures and buildings. To protect those targets against lightning are used Lightning Protection Systems (LPS). However, there are some temporary outdoor activities and backcountry places where an adequate LPS cannot be set up mainly due to the large dimensions of its components and its heavy weight. On the search of light weight lightning protection materials that can be used as part of special LPS, we research some types of electroconductive fabrics by applying high lightning impulse currents in laboratory. The fabric samples checked were pieces of 10 cm x 10 cm: two rip-stop type, a plain-weave, a non-woven and a carbon-impregnated polymeric, all of them obtained commercially. Under laboratory conditions, these samples were subject to subsequent lightning impulse currents registering the voltage and current signals. Optical and scanning electron microscope inspections were performed after tests. Despite some changes visualized as marks left on the fabric surface, the results show that investigated conductive textiles can endure ground currents produced by atmospheric lightning since they withstand the several applied laboratory lightning impulse currents. The outcomes suggest that the weave pattern of the conductive fabric influences the lightning current tolerance, enabling some conductive fabrics to be used in heavy-current applications and as part of personal LPS for outdoor, backcountry and mobile shelters, particularly when lightweight and portability are mandatory
Extragalactic magnetism with SOFIA (SALSA Legacy Program) -- V: First results on the magnetic field orientation of galaxies
We present the analysis of the magnetic field (-field) structure of
galaxies measured with far-infrared (FIR) and radio (3 and 6 cm) polarimetric
observations. We use the first data release of the Survey on extragALactic
magnetiSm with SOFIA (SALSA) of 14 nearby ( Mpc) galaxies with resolved (5
arcsec-18 arcsec; pc-- kpc) imaging polarimetric observations using
HAWC+/SOFIA from to \um. We compute the magnetic pitch angle
() profiles as a function of the galactrocentric radius. We introduce
a new magnetic alignment parameter () to estimate the
disordered-to-ordered -field ratio in spiral -fields. We find FIR and
radio wavelengths to not generally trace the same -field morphology in
galaxies. The profiles tend to be more ordered with galactocentric
radius in radio () than in FIR
(). For spiral galaxies, FIR -fields
are \% more turbulent than the radio -fields. For starburst galaxies,
we find that FIR polarization is a better tracer of the -fields along the
galactic outflows than radio polarization. Our results suggest that the
-fields associated with dense, dusty, turbulent star-forming regions, those
traced at FIR, are less ordered than warmer, less-dense regions, those traced
at radio, of the interstellar medium. The FIR -fields seem to be more
sensitive to the activity of the star-forming regions and the morphology of the
molecular clouds within a vertical height of few hundred pc in the disk of
spiral galaxies than the radio -fields.Comment: 26 pages, 13 figure
MicroRNA expression profiling in Imatinib-resistant Chronic Myeloid Leukemia patients without clinically significant ABL1-mutations
The development of Imatinib Mesylate (IM), the first specific inhibitor of BCR-ABL1, has had a major impact in patients with Chronic Myeloid Leukemia (CML), establishing IM as the standard therapy for CML. Despite the clinical success obtained with the use of IM, primary resistance to IM and molecular evidence of persistent disease has been observed in 20-25% of IM treated patients. The existence of second generation TK inhibitors, which are effective in patients with IM resistance, makes identification of predictors of resistance to IM an important goal in CML. In this study, we have identified a group of 19 miRNAs that may predict clinical resistance to IM in patients with newly diagnosed CML
Frequent and simultaneous epigenetic inactivation of TP53 pathway genes in acute lymphoblastic leukemia
Aberrant DNA methylation is one of the most frequent alterations in patients with Acute Lymphoblastic Leukemia (ALL).
Using methylation bead arrays we analyzed the methylation status of 807 genes implicated in cancer in a group of ALL
samples at diagnosis (n = 48). We found that 154 genes were methylated in more than 10% of ALL samples. Interestingly,
the expression of 13 genes implicated in the TP53 pathway was downregulated by hypermethylation. Direct or indirect
activation of TP53 pathway with 5-aza-29-deoxycitidine, Curcumin or Nutlin-3 induced an increase in apoptosis of ALL cells.
The results obtained with the initial group of 48 patients was validated retrospectively in a second cohort of 200 newly
diagnosed ALL patients. Methylation of at least 1 of the 13 genes implicated in the TP53 pathway was observed in 78% of
the patients, which significantly correlated with a higher relapse (p = 0.001) and mortality (p,0.001) rate being an
independent prognostic factor for disease-free survival (DFS) (p = 0.006) and overall survival (OS) (p = 0.005) in the
multivariate analysis. All these findings indicate that TP53 pathway is altered by epigenetic mechanisms in the majority of
ALL patients and correlates with prognosis. Treatments with compounds that may reverse the epigenetic abnormalities or
activate directly the p53 pathway represent a new therapeutic alternative for patients with ALL
Extragalactic Magnetism with SOFIA (SALSA Legacy Program). VII. A tomographic view of far infrared and radio polarimetric observations through MHD simulations of galaxies
The structure of magnetic fields in galaxies remains poorly constrained,
despite the importance of magnetism in the evolution of galaxies. Radio
synchrotron and far-infrared dust polarization (FIR) polarimetric observations
are the best methods to measure galactic scale properties of magnetic fields in
galaxies beyond the Milky Way. We use synthetic polarimetric observations of a
simulated galaxy to identify and quantify the regions, scales, and interstellar
medium (ISM) phases probed at FIR and radio wavelengths. Our studied suite of
magnetohydrodynamical cosmological zoom-in simulations features
high-resolutions (10 pc full-cell size) and multiple magnetization models. Our
synthetic observations have a striking resemblance to those of observed
galaxies. We find that the total and polarized radio emission extends to
approximately double the altitude above the galactic disk (half-intensity disk
thickness of kpc)
relative to the FIR total and polarized emission that are concentrated in the
disk midplane ( kpc).
Radio emission traces magnetic fields at scales of pc, whereas
FIR emission probes magnetic fields at the smallest scales of our simulations.
These scales are comparable to our spatial resolution and well below the
spatial resolution ( pc) of existing FIR polarimetric measurements.
Finally, we confirm that synchrotron emission traces a combination of the warm
neutral and cold neutral gas phases, whereas FIR emission follows the densest
gas in the cold neutral phase in the simulation. These results are independent
of the ISM magnetic field strength. The complementarity we measure between
radio and FIR wavelengths motivates future multiwavelength polarimetric
observations to advance our knowledge of extragalactic magnetism.Comment: Submitted to ApJ. 32 pages, 15 figure
Extragalactic Magnetism with SOFIA (SALSA Legacy Program). VII. A Tomographic View of Far-infrared and Radio Polarimetric Observations through MHD Simulations of Galaxies
The structure of magnetic fields in galaxies remains poorly constrained, despite the importance of magnetism in the evolution of galaxies. Radio synchrotron and far-infrared (FIR) polarization and polarimetric observations are the best methods to measure galactic scale properties of magnetic fields in galaxies beyond the Milky Way. We use synthetic polarimetric observations of a simulated galaxy to identify and quantify the regions, scales, and interstellar medium (ISM) phases probed at FIR and radio wavelengths. Our studied suite of magnetohydrodynamical cosmological zoom-in simulations features high-resolutions (10 pc full-cell size) and multiple magnetization models. Our synthetic observations have a striking resemblance to those of observed galaxies. We find that the total and polarized radio emission extends to approximately double the altitude above the galactic disk (half-intensity disk thickness of h I radio ∼ h PI radio = 0.23 ± 0.03 kpc) relative to the total FIR and polarized emission that are concentrated in the disk midplane (h I FIR ∼ h PI FIR = 0.11 ± 0.01 kpc). Radio emission traces magnetic fields at scales of ≳300 pc, whereas FIR emission probes magnetic fields at the smallest scales of our simulations. These scales are comparable to our spatial resolution and well below the spatial resolution (<300 pc) of existing FIR polarimetric measurements. Finally, we confirm that synchrotron emission traces a combination of the warm neutral and cold neutral gas phases, whereas FIR emission follows the densest gas in the cold neutral phase in the simulation. These results are independent of the ISM magnetic field strength. The complementarity we measure between radio and FIR wavelengths motivates future multiwavelength polarimetric observations to advance our knowledge of extragalactic magnetism
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Mediation of coffee-induced improvements in human vascular function by chlorogenic acids and its metabolites: two randomized, controlled, crossover intervention trials
Background & aims
Polyphenol intake has been linked to improvements in human vascular function, although data on hydroxycinnamates, such as chlorogenic acid (CGA) have not yet been studied. We aimed to investigate the impact of coffee intake rich in chlorogenic acid on human vascular function and whether CGAs are involved in potential effects.
Methods
Two acute randomized, controlled, cross-over human intervention trials were conducted. The impact of coffee intake, matched for caffeine but differing in CGA content (89, and 310 mg) on flow-mediated dilation (FMD) was assessed in 15 healthy male subjects. In a second intervention trial conducted with 24 healthy male subjects, the impact of pure 5-caffeoylquinic acid (5-CQA), the main CGA in coffee (5-CQA; 450 mg and 900 mg) on FMD was also investigated.
Results
We observed a bi-phasic FMD response after low and high polyphenol, (89 mg and 310 mg CGA) intake, with increases at 1 (1.10 ± 0.43% and 1.34 ± 0.62%, respectively) and 5 (0.79% ± 0.32 and 1.52% ± 0.40, respectively) hours post coffee consumption. FMD responses to coffee intake was closely paralleled by the appearance of CGA metabolites in plasma, notably 3-, 4- and 5-CQA and ferulic-4′-O-sulfate at 1 h and isoferulic-4′-O-glucuronide and ferulic-4′-O-sulfate at 5 h. Intervention with purified 5-CQA (450 mg) also led to an improvement in FMD response relative to control (0.75 ± 1.31% at 1 h post intervention, p = 0.06) and concomitant appearance of plasma metabolites.
Conclusions
Coffee intake acutely improves human vascular function, an effect, in part, mediated by 5-CQA and its physiological metabolites
Searching for a Stochastic Background of Gravitational Waves with LIGO
The Laser Interferometer Gravitational-wave Observatory (LIGO) has performed
the fourth science run, S4, with significantly improved interferometer
sensitivities with respect to previous runs. Using data acquired during this
science run, we place a limit on the amplitude of a stochastic background of
gravitational waves. For a frequency independent spectrum, the new limit is
. This is currently the most sensitive
result in the frequency range 51-150 Hz, with a factor of 13 improvement over
the previous LIGO result. We discuss complementarity of the new result with
other constraints on a stochastic background of gravitational waves, and we
investigate implications of the new result for different models of this
background.Comment: 37 pages, 16 figure
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