238 research outputs found
The pregnancy microbiome and preterm birth
Preterm birth is a global health concern and continues to contribute to substantial neonatal morbidity and mortality despite advances in obstetric and neonatal care. The underlying aetiology is multi-factorial and remains incompletely understood. In this review, the complex interplay between the vaginal microbiome in pregnancy and its association with preterm birth is discussed in depth. Advances in the study of bacteriology and an improved understanding of the human microbiome have seen an improved awareness of the vaginal microbiota in both health and in disease
Physiological responses of cultured bovine granulosa cells to elevated temperatures under low and high oxygen in the presence of different concentrations of melatonin
Our understanding of the effects of temperature on granulosa cell (GC) physiology is primarily limited to in vitro studies conducted under atmospheric (approx 20% O2) conditions. In the current series of factorial experiments we identify important effects of O2 level (i.e. 5% vs 20% O2) on GC viability and steroidogenesis, and go onto report effects of standard (37.5°C) vs high (40.0°C) temperatures under more physiologically representative (i.e. 5%) O2 levels in the presence of different levels of melatonin (0, 20, 200 and 2000 pg/mL); a potent free-radical scavenger and abundant molecule within the ovarian follicle. Cells aspirated from antral (4 to 6 mm) follicles were cultured in fibronectin-coated wells using serum-free M199 for up to 144 h. At 37.5 C viable cell number was enhanced and luteinization reduced under 5 vs 20% O2. Oxygen level interacted (P<0.001) with time in culture to affect aromatase activity and cell estradiol (E2) production (pg/mL/105 cells). These decreased between 48 and 96 h for both O2 levels but increased again by 144 h for cells cultured under 5% but not 20% O2. Progesterone (P4) concentration (ng/mL/105 cells) was greater (P<0.001) under 20 vs 5% O2 at 96 and 144 h. Cell number increased (P<0.01) with time in culture under 5% O2 irrespective of temperature. However, higher doses of melatonin increased viable cell number at 40.0°C but reduced viable cell number at 37.5°C (P=0.004). Melatonin also reduced (P<0.001) ROS generation at both O2 levels across all concentrations. E2 increased with time in culture at both temperatures under 5% O2, however P4 declined between 96 to 144 h at 40.0 but not 37.5°C. Furthermore, melatonin interacted (P<0.001) with temperature in a dose dependent manner to increase P4 at 37.5°C but to reduce P4 at 40.0°C. Transcript expression for HSD3B1 paralleled temporal changes in P4 production, and those for HBA were greater at 5% than 20% O2, suggesting that hemoglobin synthesis is responsive to changes in O2 level. In conclusion, 5% O2 enhances GC proliferation and reduces luteinization. Elevated temperatures under 5% O2 reduce GC proliferation and P4 production. Melatonin reduces ROS generation irrespective of O2 level and temperature, but interacts with temperature in a dose dependent manner to influence GC proliferation and luteinization
A prediction of -multi- states
We present a study of the many-body interaction between a and
multi-. We use an extrapolation to SU(4) of the hidden gauge formalism,
which produced dynamically the resonances in the
interaction and in the interaction. Then let a third
particle, , , or a resonance collide with them, evaluating the
scattering amplitudes in terms of the Fixed Center Approximation of the Faddeev
equations. We find several clear resonant structures above 2800\mev in the
multibody scattering amplitudes. They would correspond to new charmed
resonances, , , and , which are not yet listed in
the PDG, which would be analogous to the , ,
, and , ,
described before as multi- and -multi- states respectively
Strategy to find the two states from lattice QCD simulations
Theoretical studies within the chiral unitary approach, and recent
experiments, have provided evidence of the existence of two isoscalar states in
the region of the . In this paper we use the same chiral
approach to generate energy levels in a finite box. In a second step, assuming
that these energies correspond to lattice QCD results, we devise the best
strategy of analysis to obtain the two states in the infinite volume case, with
sufficient precision to distinguish them. We find out that using energy levels
obtained with asymmetric boxes and/or with a moving frame, with reasonable
errors in the energies, one has a successful scheme to get the two
poles.Comment: Published version (more discussions added based on referee's
suggestions, giving rise to a new section: IV
Gamma ray and neutron radiation effects on the electrical and structural properties of n-ZnO/p-CuGaO2 schottky diode
This research focuses on the radiation tolerance of ZnO and CuGaO2 based semiconductor application for space borne application. In this research, n-ZnO/p-CuGaO2 based semiconductor devices were fabricated and exposed to gamma rays with increasing total ionizing dose (TID) and neutron fluence at different flux. Based on the I-V properties, the decrease in the turn-on voltage of the diode is noticeable with increasing radiation dose for both gamma and neutron flux exposure. The maximum turn-on-voltage of the fabricated diode was shown to be 1.5 V. Exposure towards gamma, shows that the turn-on is increased to 4.7 V at 200 kGy. However, the effect of neutron flux at 6.5 Ă 1015 n cmâ2 shows a small significant effect on the turn on voltage of 1.7 V after irradiation. Results show moderate mitigation towards irradiation, indicating that n-ZnO/p-CuGaO2 thin film is capable of withstanding harsh radiation environment while still retaining its semiconductor as the changes in band gap ranges between 3 eV to 4 eV at post-irradiation
A new perspective on the Faddeev equations and the system from chiral dynamics and unitarity in coupled channels
We review recent work concerning the interaction and Faddeev
equations with chiral dynamics which allow us to look at the from a
different perspective and pay attention to problems that have been posed in
previous studies on the subject. We show results which provide extra
experimental evidence on the existence of two states. We then
show the findings of a recent approach to Faddeev equations using chiral
unitary dynamics, where an explicit cancellation of the two body off shell
amplitude with three body forces stemming from the same chiral Lagrangians
takes place. This removal of the unphysical off shell part of the amplitudes is
most welcome and renders the approach unambiguous, showing that only on shell
two body amplitudes need to be used. With this information in mind we use an
approximation to the Faddeev equations within the fixed center approximation to
study the system, providing answers within this approximation to
questions that have been brought before and evaluating binding energies and
widths of this three body system. As a novelty with respect to recent work on
the topic we find a bound state of the system with spin S=1, like a bound state
of -deuteron, less bound that the one of S=0, where all recent efforts
have been devoted. The width is relatively large in this case, suggesting
problems in a possible experimental observation.Comment: 18 pages, 7 figures, one misprint corrected, Nuclear Physics A in
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Use of Cholecystokinin to Prevent the Development of Parenteral Nutritionâ Associated Cholestasis
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142290/1/jpen0100.pd
Botanical and Genetic Identification Followed by Investigation of Chemical Composition and Biological Activities on the Scabiosa atropurpurea L. Stem from Tunisian Flora
Scarce information about the phenolic composition of Scabiosa atropurpurea L. is available, and no carotenoid compounds have been reported thus far. In this study the phenolic and carotenoid composition of this plant was both investigated and associated bioactivities were evaluated. Aiming to obtain extracts and volatile fractions of known medicinal plants to valorize them in the pharmaceutical or food industries, two techniques of extraction and five solvents were used to determine the biologically active compounds. Gas chromatography coupled to flame ionization and mass spectrometry and liquid chromatography coupled to photodiode array and atmospheric pressure chemical ionization/electrospray ionization mass spectrometry highlighted the presence of 15 volatiles, 19 phenolic, and 24 natural pigments in Scabiosa atropurpurea L. stem samples; among them, the most abundant were 1,8-cineole, chlorogenic acid, cynaroside, and lutein. Bioactivity was assessed by a set of in vitro tests checking for antioxidant, antibacterial, antifungal, and allelopathic (against Brassica oleracea L. and Lens culinaris Medik) effects. Scabiosa atropurpurea L. stem extracts presented a considerable antioxidant, antibacterial, and allelopathic potential, with less antifungal effectiveness. These results indicate that the volatile fractions and extracts from S. atropurpurea L. stem could be considered as a good source of bioactive agents, with possible applications in food-related, agriculture, and pharmaceutical fields. Genetic investigations showed 97% of similarity with Scabiosa tschiliensis, also called Japanese Scabiosa
Analysis of Various Polarization Asymmetries In The Inclusive Decay In The Fourth-Generation Standard Model
In this study a systematical analysis of various polarization asymmetries in
inclusive b \rar s \ell^+ \ell^- decay in the standard model (SM) with four
generation of quarks is carried out. We found that the various asymmetries are
sensitive to the new mixing and quark masses for both of the and
channels. Sizeable deviations from the SM values are obtained. Hence, b \rar s
\ell^+ \ell^- decay is a valuable tool for searching physics beyond the SM,
especially in the indirect searches for the fourth-generation of quarks (.Comment: 19 Pages, 10 Figures, 3 Table
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