2,597 research outputs found
Factors associated with failed treatment : an analysis of 121,744 women embarking on their first IVF cycles
Peer reviewedPublisher PD
Schottky Diodes on ZnO Thin Films Grown by Plasma-Enhanced Atomic Layer Deposition
Enhancement of the properties of zinc oxide (ZnO)-based Schottky diodes has been explored using a combination of plasma-enhanced atomic layer deposition (PE-ALD) ZnO thin films and silver oxide Schottky contacts deposited by reactive radio-frequency sputtering. The electrical properties of the ZnO thin films were systematically tuned by varying the deposition temperature and oxygen plasma time during PE-ALD to optimize the performance of the diode. Low temperature (80 °C) coupled with relatively long oxygen plasma time (>30 s) PE-ALD is the key to produce ZnO films with net doping concentration lower than 10 17 cm -3 . Under the optimal deposition conditions identified, the diode shows an ideality factor of 1.33, an effective barrier height of 0.80 eV, and an ON/OFF ratio of 3.11 × 10 5
Role of macrophage sialoadhesin in host defense against the sialylated pathogen group B <em>Streptococcus</em>
ABSTRACT: Several bacterial pathogens decorate their surfaces with sialic acid (Sia) residues within cell wall components or capsular exopolysaccharides. Sialic acid expression can promote bacterial virulence by blocking complement activation or by engagement of inhibitory sialic acid-binding immunoglobulin-like lectins (Siglecs) on host leukocytes. Expressed at high levels on splenic and lymph node macrophages, sialoadhesin (Sn) is a unique Siglec with an elongated structure that lacks intracellular signaling motifs. Sialoadhesin allows macrophage to engage certain sialylated pathogens and stimulate inflammatory responses, but the in vivo significance of sialoadhesin in infection has not been shown. We demonstrate that macrophages phagocytose the sialylated pathogen group B Streptococcus (GBS) and increase bactericidal activity via sialoadhesin-sialic-acid-mediated recognition. Sialoadhesin expression on marginal zone metallophillic macrophages in the spleen trapped circulating GBS and restricted the spread of the GBS to distant organs, reducing mortality. Specific IgM antibody responses to GBS challenge were also impaired in sialoadhesin-deficient mice. Thus, sialoadhesin represents a key bridge to orchestrate innate and adaptive immune defenses against invasive sialylated bacterial pathogens. KEY MESSAGE: Sialoadhesin is critical for macrophages to phagocytose and clear GBS. Increased GBS organ dissemination in the sialoadhesin-deficient mice. Reduced anti-GBS IgM production in the sialoadhesin-deficient mice. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00109-014-1157-y) contains supplementary material, which is available to authorized users
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Hybrid spectrum access with relay assisting both primary and secondary networks under imperfect spectrum sensing
This paper proposes a novel hybrid interweave-underlay spectrum access for a cognitive amplify-and-forward relay network where the relay forwards the signals of both the primary and secondary networks. In particular, the secondary network (SN) opportunistically operates in interweave spectrum access mode when the primary network (PN) is sensed to be inactive and switches to underlay spectrum access mode if the SN detects that the PN is active. A continuous-time Markov chain approach is utilized to model the state transitions of the system. This enables us to obtain the probability of each state in the Markov chain. Based on these probabilities and taking into account the impact of imperfect spectrum sensing of the SN, the probability of each operation mode of the hybrid scheme is obtained. To assess the performance of the PN and SN, we derive analytical expressions for the outage probability, outage capacity, and symbol error rate over Nakagami-m fading channels. Furthermore, we present comparisons between the performance of underlay cognitive cooperative radio networks (CCRNs) and the performance of the considered hybrid interweave-underlay CCRN in order to reveal the advantages of the proposed hybrid spectrum access scheme. Eventually, with the assistance of the secondary relay, performance improvements for the PN are illustrated by means of selected numerical results
Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.
Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
Dynamic behavior analysis via structured rank minimization
Human behavior and affect is inherently a dynamic phenomenon involving temporal evolution of patterns manifested through a multiplicity of non-verbal behavioral cues including facial expressions, body postures and gestures, and vocal outbursts. A natural assumption for human behavior modeling is that a continuous-time characterization of behavior is the output of a linear time-invariant system when behavioral cues act as the input (e.g., continuous rather than discrete annotations of dimensional affect). Here we study the learning of such dynamical system under real-world conditions, namely in the presence of noisy behavioral cues descriptors and possibly unreliable annotations by employing structured rank minimization. To this end, a novel structured rank minimization method and its scalable variant are proposed. The generalizability of the proposed framework is demonstrated by conducting experiments on 3 distinct dynamic behavior analysis tasks, namely (i) conflict intensity prediction, (ii) prediction of valence and arousal, and (iii) tracklet matching. The attained results outperform those achieved by other state-of-the-art methods for these tasks and, hence, evidence the robustness and effectiveness of the proposed approach
BRIT1/MCPH1 links chromatin remodelling to DNA damage response
To detect and repair damaged DNA, DNA damage response proteins need to overcome the barrier of condensed chromatin to gain access to DNA lesions1. ATP-dependent chromatin remodeling is one of the fundamental mechanisms used by cells to relax chromatin in DNA repair2–3. However, the mechanism mediating their recruitment to DNA lesions remains largely unknown. BRIT1 (also known as MCPH1) is an early DNA damage response protein that is mutated in human primary microcephaly4–8. We report here a previously unknown function of BRIT1 as a regulator of ATP-dependent chromatin remodeling complex SWI/SNF in DNA repair. Upon DNA damage, BRIT1 increases its interaction with SWI/SNF through the ATM/ATR-dependent phosphorylation on the BAF170 subunit. This increase of binding affinity provides a means by which SWI/SNF can be specifically recruited to and maintained at DNA lesions. Loss of BRIT1 causes impaired chromatin relaxation owing to reduced association of SWI/SNF with chromatin. This explains the decreased recruitment of repair proteins to DNA lesions and reduced efficiency of repair in BRIT1-deficient cells, resulting in impaired survival from DNA damage. Our findings, therefore, identify BRIT1 as a key molecule that links chromatin remodeling with DNA damage response in the control of DNA repair, and its dysfunction contributes to human disease
Local and systemic effect of transfection-reagent formulated DNA vectors on equine melanoma
Background Equine melanoma has a high incidence in grey horses. Xenogenic DNA
vaccination may represent a promising therapeutic approach against equine
melanoma as it successfully induced an immunological response in other species
suffering from melanoma and in healthy horses. In a clinical study, twenty-
seven, grey, melanoma-bearing, horses were assigned to three groups (n = 9)
and vaccinated on days 1, 22, and 78 with DNA vectors encoding for equine (eq)
IL-12 and IL-18 alone or in combination with either human glycoprotein (hgp)
100 or human tyrosinase (htyr). Horses were vaccinated intramuscularly, and
one selected melanoma was locally treated by intradermal peritumoral
injection. Prior to each injection and on day 120, the sizes of up to nine
melanoma lesions per horse were measured by caliper and ultrasound. Specific
serum antibodies against hgp100 and htyr were measured using cell based flow-
cytometric assays. An Analysis of Variance (ANOVA) for repeated measurements
was performed to identify statistically significant influences on the relative
tumor volume. For post-hoc testing a Tukey-Kramer Multiple-Comparison Test was
performed to compare the relative volumes on the different examination days.
An ANOVA for repeated measurements was performed to analyse changes in body
temperature over time. A one-way ANOVA was used to evaluate differences in
body temperature between the groups. A p–value < 0.05 was considered
significant for all statistical tests applied. Results In all groups, the
relative tumor volume decreased significantly to 79.1 ± 26.91% by day 120 (p <
0.0001, Tukey-Kramer Multiple-Comparison Test). Affiliation to treatment
group, local treatment and examination modality had no significant influence
on the results (ANOVA for repeated measurements). Neither a cellular nor a
humoral immune response directed against htyr or hgp100 was detected. Horses
had an increased body temperature on the day after vaccination. Conclusions
This is the first clinical report on a systemic effect against equine melanoma
following treatment with DNA vectors encoding eqIL12 and eqIL18 and formulated
with a transfection reagent. Addition of DNA vectors encoding hgp100
respectively htyr did not potentiate this effect
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