1,162 research outputs found
Amniotic fluid absorption and growth functions in humans: what can we indirectly learn from congenital digestive atresias?
Background: Amniotic fluid (AF) was thought of just as a mechanical cushioning to the foetus. Nowadays, its role
during pregnancy is getting more attention, suggesting hitherto unknown aspects. The aim of the study is to speculate
on AF nutritional functions and its clinical repercussions based on what digestive tract (DT) atresias seem to
suggest.
Methods: A retrospective analysis of the patients admitted to our department for DT atresias between 2000 and
2020 was conducted. Patientsâ birth weight (BW), gestational age (GA) at birth and diagnosis were recorded. The following
were excluded from the study: oesophageal atresias (OA) with tracheoesophageal fistula (TOF), colonic and
anal atresias and patients with associated major comorbidities. A control group was made of patients admitted to
our ward in the same period for congenital pulmonary airway malformations (CPAM). To standardize the BW, it was
coupled with birth GA calculating the newborn percentiles. The mean newborn percentiles of OAs, duodenal atresias
(DAs), jejunal atresias (JAs), and ileal atresias (IAs) were independently compared with the control group using Studentâs
t-test. Lastly, the significance of the frequenciesâ distribution of newborns born small for gestational age (SGA)
between the DT atresias and the control group was evaluated with the Ï2 test, and the OR were calculated. A p-value
< 0.05 was considered statistically significant.
Results: A total of 231 patients were eligible for the study: 36 OAs without TOF, mean BW 2488.8 ± 491 g (range
1630â3750 g), mean GA 36.8 ± 2.1 weeks (31â40 weeks), mean newborn percentile 18 ± 22 (1â75); 20 DAs, mean BW
2586.8 ± 577.9 g (1250â3462 g), mean GA 36.2 ± 2.5 weeks (31â40 weeks), mean newborn percentile 31 ± 23 (3â79);
17 JAs, mean BW 2483.5 ± 621.7 g (900â3205 g), mean GA 34.8 ± 2.1 weeks (30â38 weeks), mean newborn percentile
44 ± 28 (4â96); 17 IAs, mean BW 2646.1 ± 769.8 g (1162.0â3888 g), mean GA 35.9 ± 3.2 weeks (30â41 weeks), mean
newborn percentile 44 ± 26 (1â82); and 141 CPAMs with mean BW 3287.4 ± 492.0 g (980â4580 g), mean GA 38.7 ±
1.8 weeks (26â41 weeks), mean newborn percentile 43 ± 26 (1â99). The number of SGA neonates was 18 between
OA patients (50%), 4 between DAs (20%), 1 between JAs (6%), 2 between IAs (12%) and 11 between CPAMs (8%). The
mean percentile of the OAs and DAs was lower than the control group with a p of < .01 and .03 while no statistical significance
was found in the comparison between DAs, JAs, IAs and CPAMs with a p of .06, .86 and .59. The incidence of
SGA in the control group resulted lower than the one in the DT atresias where it becomes higher the more proximal
the atresia is (p < .05). The OR of SGA newborn in the OA group was 11.8, in DA 3.0, in JA 0.7 and in IA 1.6.
Conclusion: AF showed to have a great impact on foetal growth, and its preferred site of absorption seemed to be
the stomach and duodenum. Its nutritional role could have an important predictive value in diagnosing DT atresia
both prenatally and postnatally
Response of the bacterial communities associated with maize rhizosphere to poultry litter as an organomineral fertilizer.
Maize is an important food source worldwide and is of considerable industrial importance. Low maize yields are mostly due to low soil fertility, so expensive mineral fertilizers are often used to offset the lack of nutrients. Poultry litter (PL) is one of the most valuable and phosphorous-rich animal wastes. However, PL usually contains veterinary antibiotic residues, particularly fluoroquinolones (FQs), which may alter soil microorganism diversity and resistance patterns. In this study, we aimed to understand the impact of applying mineral (triple superphosphate?STP) or organomineral (STP with PL and reactive Bayovar phosphate with PL) fertilizers (130 or 260 kg/ha of total P2O5) on the structure and composition of the soil bacteriome and on phosphate-mineralizing bacteria associated with the maize rhizosphere. Maize plants were sampled at 60 and 90 days after sowing and a clear rhizosphere effect was observed in all samples. No specific groups of bacterial genera predominated (>3% relative abundance) according to the different fertilizer treatments and most of the genera were shared among samples. Multivariate analyses of 16S rRNA sequences revealed clear clustering based on sampling time and distinct separation from bulk soil samples. Abundances of phosphate-mineralizing bacteria varied depending on the sampling time.We observed a positive effect on phytase activity under the 260 kg STP with PL treatment. Although the FQ enrofloxacin and its main metabolite ciprofloxacin were detected in PL, their concentrations in fertilized soils were below quantification thresholds. Quinolone resistance genes were not detected in the maize rhizosphere or bulk soil. Together, these results suggest that the rhizosphere effect, plant age and applied amounts of fertilizer are more influential on bacterial communities than the type of fertilizer used. Thus, application of PL as an organomineral fertilizer does not appear to have extensive impacts on the bacterial diversity of maize rhizosphere, so it could be an excellent option for enhancing maize production
Neutrino Detection with Inclined Air Showers
The possibilities of detecting high energy neutrinos through inclined showers
produced in the atmosphere are addressed with an emphasis on the detection of
air showers by arrays of particle detectors. Rates of inclined showers produced
by both down-going neutrino interactions and by up-coming decays from
earth-skimming neutrinos as a function of shower energy are calculated with
analytical methods using two sample neutrino fluxes with different spectral
indices. The relative contributions from different flavors and charged, neutral
current and resonant interactions are compared for down-going neutrinos
interacting in the atmosphere. No detailed description of detectors is
attempted but rough energy thresholds are implemented to establish the ranges
of energies which are more suitable for neutrino detection through inclined
showers. Down-going and up-coming rates are compared.Comment: Submitted to New Journal of Physic
Efficient Symmetry Reduction and the Use of State Symmetries for Symbolic Model Checking
One technique to reduce the state-space explosion problem in temporal logic
model checking is symmetry reduction. The combination of symmetry reduction and
symbolic model checking by using BDDs suffered a long time from the
prohibitively large BDD for the orbit relation. Dynamic symmetry reduction
calculates representatives of equivalence classes of states dynamically and
thus avoids the construction of the orbit relation. In this paper, we present a
new efficient model checking algorithm based on dynamic symmetry reduction. Our
experiments show that the algorithm is very fast and allows the verification of
larger systems. We additionally implemented the use of state symmetries for
symbolic symmetry reduction. To our knowledge we are the first who investigated
state symmetries in combination with BDD based symbolic model checking
Exploring E-cadherin-peptidomimetics interaction using NMR and computational studies
Cadherins are homophilic cell-cell adhesion molecules whose aberrant expression has often been shown to correlate with different stages of tumor progression. In this work, we investigate the interaction of two peptidomimetic ligands with the extracellular portion of human E-cadherin using a combination of NMR and computational techniques. Both ligands have been previously developed as mimics of the tetrapeptide sequence Asp1-Trp2-Val3-Ile4 of the cadherin adhesion arm, and have been shown to inhibit E-cadherin-mediated adhesion in epithelial ovarian cancer cells with millimolar potency. To sample a set of possible interactions of these ligands with the E-cadherin extracellular portion, STD-NMR experiments in the presence of two slightly different constructs, the wild type E-cadherin-EC1-EC2 fragment and the truncated E-cadherin-(Val3)-EC1-EC2 fragment, were carried out at three temperatures. Depending on the protein construct, a different binding epitope of the ligand and also a different temperature effect on STD signals were observed, both suggesting an involvement of the Asp1-Trp2 protein sequence among all the possible binding events. To interpret the experimental results at the atomic level and to probe the role of the cadherin adhesion arm in the dynamic interaction with the peptidomimetic ligand, a computational protocol based on docking calculations and molecular dynamics simulations was applied. In agreement with NMR data, the simulations at different temperatures unveil high variability/dynamism in ligand-cadherin binding, thus explaining the differences in ligand binding epitopes. In particular, the modulation of the signals seems to be dependent on the protein flexibility, especially at the level of the adhesive arm, which appears to participate in the interaction with the ligand. Overall, these results will help the design of novel cadherin inhibitors that might prevent the swap dimer formation by targeting both the Trp2 binding pocket and the adhesive arm residues.
Author summary Classical cadherins are the main adhesive proteins at the intercellular junctions and play an essential role in tissue morphogenesis and homeostasis. A large number of studies have shown that cadherin aberrant expression and/or dysregulation often correlate with pathological processes, such as tumor development and progression. Notwithstanding the emerging role played by cadherins in a number of solid tumors, the rational design of small inhibitors targeting these proteins is still in its infancy, likely due to the challenges posed by the development of small drug-like molecules that modulate protein-protein interactions and to the structural complexity of the various cadherin dimerization interfaces that constantly form and disappear as the protein moves along its highly dynamic and reversible homo-dimerization trajectory. In this work, we study the interaction of two small molecules with the extracellular portion of human E-cadherin using a combination of spectroscopic and computational techniques. The availability of molecules interfering in the cadherin homophilic interactions could provide a useful tool for the investigation of cadherin function in tumors, and potentially pave the way to the development of novel alternative diagnostic and therapeutic interventions in cadherin-expressing solid tumors
Relativistic quantum dynamics in strong fields: Photon emission from heavy, few-electron ions
Recent progress in the study of the photon emission from highly-charged heavy
ions is reviewed. These investigations show that high- ions provide a unique
tool for improving the understanding of the electron-electron and
electron-photon interaction in the presence of strong fields. Apart from the
bound-state transitions, which are accurately described in the framework of
Quantum Electrodynamics, much information has been obtained also from the
radiative capture of (quasi-) free electrons by high- ions. Many features in
the observed spectra hereby confirm the inherently relativistic behavior of
even the simplest compound quantum systems in Nature.Comment: Version 18/11/0
Formalin-fixed and paraffin-embedded samples for next generation sequencing: Problems and solutions
Over the years, increasing information has been asked of the pathologist: we have moved from a purely morphological diagnosis to biomolecular and genetic studies, which have made it possible to implement the use of molecular targeted therapies, such as anti-epidermal growth factor receptor (EGFR) molecules in EGFR-mutated lung cancer, for example. Today, next generation sequencing (NGS) has changed the approach to neoplasms, to the extent that, in a short time, it has gained a place of absolute importance and diagnostic, prognostic and therapeutic utility. In this scenario, formaldehyde-fixed and paraffin-embedded (FFPE) biological tissue samples are a source of clinical and molecular information. However, problems can arise in the genetic material (DNA and RNA) for use in NGS due to fixation, and work is being devoted to possible strategies to reduce its effects. In this paper, we discuss the applications of FFPE tissue samples in the execution of NGS, we focus on the problems arising with the use of this type of material for nucleic acid extraction and, finally, we consider the most useful strategies to prevent and reduce single nucleotide polymorphisms (SNV) and other fixation artifacts
Measurement of the Depth of Maximum of Extensive Air Showers above 10^18 eV
We describe the measurement of the depth of maximum, Xmax, of the
longitudinal development of air showers induced by cosmic rays. Almost four
thousand events above 10^18 eV observed by the fluorescence detector of the
Pierre Auger Observatory in coincidence with at least one surface detector
station are selected for the analysis. The average shower maximum was found to
evolve with energy at a rate of (106 +35/-21) g/cm^2/decade below 10^(18.24 +/-
0.05) eV and (24 +/- 3) g/cm^2/decade above this energy. The measured
shower-to-shower fluctuations decrease from about 55 to 26 g/cm^2. The
interpretation of these results in terms of the cosmic ray mass composition is
briefly discussed.Comment: Accepted for publication by PR
Operations of and Future Plans for the Pierre Auger Observatory
Technical reports on operations and features of the Pierre Auger Observatory,
including ongoing and planned enhancements and the status of the future
northern hemisphere portion of the Observatory. Contributions to the 31st
International Cosmic Ray Conference, Lodz, Poland, July 2009.Comment: Contributions to the 31st ICRC, Lodz, Poland, July 200
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