1,151 research outputs found
Maternal-Fetal Medicine physiciansā practice patterns for 22-week delivery management
Objective: To describe Maternal-Fetal Medicine (MFM) physiciansā practice patterns for 22-week delivery management.
Mehods: Surveyed 750 randomly-sampled members of the Society of Maternal-Fetal Medicine, querying MFMsā practices and policies guiding 22-week delivery management.
Results: Three hundred and twenty-five (43%) MFMs responded. Nearly all (87%) would offer induction. Twenty-eight percent would order steroids, and 12% would perform cesarean for a patient desiring resuscitation. Offering induction differed significantly based on the providerās practice setting, region, religious service attendance and political affiliation. In multivariable analyses, political affiliation remained a significant predictor of offering induction (pā=ā0.03).
Conclusions: Most MFMs offer induction for PPROM at 22 weeks. A noteworthy proportion is willing to order steroids and perform cesarean. Personal beliefs and practice characteristics may contribute to these decisions. While little is known about the efficacy of these interventions at 22 weeks, some MFMs will offer obstetrical intervention if resuscitation is intended
Tryptic digestion coupled with ambient DESI and LESA mass spectrometry enables identification of skeletal muscle proteins in mixtures and distinguishes between beef, pork, horse, chicken and turkey meat
The use of ambient desorption electrospray ionization (DESI-MS) mass spectrometry and liquid extraction surface analysis mass spectrometry (LESA-MS) is explored for the first time to analyse skeletal muscle proteins obtained from mixture of standard proteins and raw meat. Single proteins and mixtures of up to five proteins (myoglobin, troponin C, actin, BSA, tropomyosin) were deposited onto a polymer surface, followed by in-situ tryptic digestion and comparative analysis using DESI-MS and LESA-MS using tandem electrospray MS. Peptide peaks specific to individual proteins were readily distinguishable with good signal-to-noise ratio in the five-component mixture. LESA-MS gave a more stable analysis and greater sensitivity compared with DESI-MS. Meat tryptic digests were subjected to peptidomics analysis by DESI-MS and LESA-MS. Bovine, horse, pig, chicken and turkey muscle digests were clearly discriminated using multivariate data analysis (MVA) of the peptidomic datasets. The most abundant skeletal muscle proteins were identified and correctly classified according to the species following MS/MS analysis. The study shows, for the first time, that ambient ionization techniques such as DESI-MS and LESA-MS have great potential for species-specific analysis and differentiation of skeletal muscle proteins by direct surface desorption
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Platelet endothelial cell adhesion molecule-1 inhibits platelet response to thrombin and von Willebrand factor by regulating the internalization of glycoprotein Ib via AKT/glycogen synthase kinase-3/dynamin and integrin Ī±IIbĪ²3
OBJECTIVE:
Platelet endothelial cell adhesion molecule-1 (PECAM-1) regulates platelet response to multiple agonists. How this immunoreceptor tyrosine-based inhibitory motif-containing receptor inhibits G protein-coupled receptor-mediated thrombin-induced activation of platelets is unknown.
APPROACH AND RESULTS:
Here, we show that the activation of PECAM-1 inhibits fibrinogen binding to integrin Ī±IIbĪ²3 and P-selectin surface expression in response to thrombin (0.1-3 U/mL) but not thrombin receptor-activating peptides SFLLRN (3Ć10(-7)-1Ć10(-5) mol/L) and GYPGQV (3Ć10(-6)-1Ć10(-4) mol/L). We hypothesized a role for PECAM-1 in reducing the tethering of thrombin to glycoprotein IbĪ± (GPIbĪ±) on the platelet surface. We show that PECAM-1 signaling regulates the binding of fluorescein isothiocyanate-labeled thrombin to the platelet surface and reduces the levels of cell surface GPIbĪ± by promoting its internalization, while concomitantly reducing the binding of platelets to von Willebrand factor under flow in vitro. PECAM-1-mediated internalization of GPIbĪ± was reduced in the presence of both EGTA and cytochalasin D or latrunculin, but not either individually, and was reduced in mice in which tyrosines 747 and 759 of the cytoplasmic tail of Ī²3 integrin were mutated to phenylalanine. Furthermore, PECAM-1 cross-linking led to a significant reduction in the phosphorylation of glycogen synthase kinase-3Ī² Ser(9), but interestingly an increase in glycogen synthase kinase-3Ī± pSer(21). PECAM-1-mediated internalization of GPIbĪ± was reduced by inhibitors of dynamin (Dynasore) and glycogen synthase kinase-3 (CHIR99021), an effect that was enhanced in the presence of EGTA.
CONCLUSIONS:
PECAM-1 mediates internalization of GPIbĪ± in platelets through dual AKT/protein kinase B/glycogen synthase kinase-3/dynamin-dependent and Ī±IIbĪ²3-dependent mechanisms. These findings expand our understanding of how PECAM-1 regulates nonimmunoreceptor signaling pathways and helps to explains how PECAM-1 regulates thrombosis
Pellets recovered from stick nests and new diet items of Furnariidae (Aves: Passeriformes)
This is the first record showing eleven species in seven genera of Furnariidae (Aves: Passeriformes) from Argentina that regurgitate pellets. A total of 627 nests of Furnariidae was examined, and from 84 nests (13.3%), 1,329 pellets were recovered. These pellets were found in the closed, domed nests of many Furnariidae, because in comparison to other passerine birds, their nests were used for roosting, especially in the subfamily Synallaxinae. Anumbius annumbi had the highest percentage of nests containing pellets. Food items identified from the pellets provided important new data on the diets of several species of Furnariidae.Fil: Turienzo, Paola NoemĆ. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y BiologĆa Experimental; Argentina. Consejo Nacional de Investigaciones CientĆficas y TĆ©cnicas; ArgentinaFil: Di Iorio, Osvaldo RubĆ©n. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y BiologĆa Experimental; Argentin
Benchmarks for identification of ordinary differential equations from time series data
Motivation: In recent years, the biological literature has seen a significant increase of reported methods for identifying both structure and parameters of ordinary differential equations (ODEs) from time series data. A natural way to evaluate the performance of such methods is to try them on a sufficient number of realistic test cases. However, weak practices in specifying identification problems and lack of commonly accepted benchmark problems makes it difficult to evaluate and compare different methods
Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Sky Maps, Systematic Errors, and Basic Results
(Abridged) New full sky temperature and polarization maps based on seven
years of data from WMAP are presented. The new results are consistent with
previous results, but have improved due to reduced noise from the additional
integration time, improved knowledge of the instrument performance, and
improved data analysis procedures. The improvements are described in detail.
The seven year data set is well fit by a minimal six-parameter flat Lambda-CDM
model. The parameters for this model, using the WMAP data in conjunction with
baryon acoustic oscillation data from the Sloan Digital Sky Survey and priors
on H_0 from Hubble Space Telescope observations, are: Omega_bh^2 = 0.02260
+-0.00053, Omega_ch^2 = 0.1123 +-0.0035, Omega_Lambda = 0.728 +0.015 -0.016,
n_s = 0.963 +-0.012, tau = 0.087 +-0.014 and sigma_8 = 0.809 +-0.024 (68 % CL
uncertainties). The temperature power spectrum signal-to-noise ratio per
multipole is greater that unity for multipoles < 919, allowing a robust
measurement of the third acoustic peak. This measurement results in improved
constraints on the matter density, Omega_mh^2 = 0.1334 +0.0056 -0.0055, and the
epoch of matter- radiation equality, z_eq = 3196 +134 -133, using WMAP data
alone. The new WMAP data, when combined with smaller angular scale microwave
background anisotropy data, results in a 3 sigma detection of the abundance of
primordial Helium, Y_He = 0.326 +-0.075.The power-law index of the primordial
power spectrum is now determined to be n_s = 0.963 +-0.012, excluding the
Harrison-Zel'dovich-Peebles spectrum by >3 sigma. These new WMAP measurements
provide important tests of Big Bang cosmology.Comment: 42 pages, 9 figures, Submitted to Astrophysical Journal Supplement
Serie
Quantum computing with spin qubits in semiconductor structures
We survey recent work on designing and evaluating quantum computing
implementations based on nuclear or bound-electron spins in semiconductor
heterostructures at low temperatures and in high magnetic fields. General
overview is followed by a summary of results of our theoretical calculations of
decoherence time scales and spin-spin interactions. The latter were carried out
for systems for which the two-dimensional electron gas provides the dominant
carrier for spin dynamics via exchange of spin-excitons in the integer quantum
Hall regime.Comment: 18 pages in PD
Indirect Interaction of Solid-State Qubits via Two-Dimensional Electron Gas
We propose a mechanism of long-range coherent coupling between nuclear spins
to be used as qubits in solid-state semiconductor-heterojunction quantum
information processing devices. The coupling is via localized donor electrons
which in turn interact with the two-dimensional electron gas. An effective
two-spin interaction Hamiltonian is derived and the coupling strength is
evaluated. We also discuss mechanisms of qubit decoherence and consider
possibilities for gate control of the interaction between neighboring qubits.
The resulting quantum computing scheme retains all the gate-control and
measurement aspects of earlier approaches, but allows qubit spacing at
distances of order 100nm, attainable with the present-day semiconductor device
technologies.Comment: 12 pages in plain Te
Authentication of processed meat products by peptidomic analysis using rapid ambient mass spectrometry
We present the application of a novel ambient LESA-MS method for the authentication of processed meat products. A set of 25 species and protein-specific heat stable peptide markers has been detected in processed samples manufactured from beef, pork, horse, chicken and turkey meat. We demonstrate that several peptides derived from myofibrillar and sarcoplasmic proteins are sufficiently resistant to processing to serve as specific markers of processed products. The LESA-MS technique required minimal sample preparation without fractionation and enabled the unambiguous and simultaneous identification of skeletal muscle proteins and peptides as well as other components of animal origin, including the milk protein such as casein alpha-S1, in whole meat product digests. We have identified, for the first time, six fast type II and five slow/cardiac type I MHC peptide markers in various processed meat products. The study demonstrates that complex mixtures of processed proteins/peptides can be examined effectively using this approach
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