433 research outputs found
3D refractive index reconstruction from phaseless coherent optical microscopy data using multiple scattering-based inverse solvers - a study
Reconstructing 3D refractive index profile of scatterers using optical microscopy measurements presents several challenges over the conventional microwave and RF domain measurement scenario. These include phaseless and polarization-insensitive measurements, small numerical aperture, as well as a Green's function where spatial frequencies are integrated in a weighted manner such that far-field angular spectrum cannot be probed and high spatial frequencies that permit better resolution are weighed down. As a result of these factors, the non-linearity and the ill-posedness of the inverse problem are quite severe. These limitations have imposed that inverse scattering problems in the microscopy domain largely consider scalar wave approximations and neglect multiple scattering. Here, we present first inverse scattering results for optical microscopy setup where full-wave vectorial formulation and multiple scattering is incorporated. We present (a) how three popular inverse scattering solvers from microwave domain can be adapted for the present inverse problem, (b) the opportunities and challenges presented by each of these solvers, (c) a comparative insight into these solvers and contrast with the simpler Born approximation approach, and (d) potential routes to improve the performance of these solvers for the hard inverse problem of optical microscopy
3D full-wave multi-scattering forward solver for coherent microscopes
A rigorous forward model solver for conventional coherent microscope is presented. The forward model is derived from Maxwell’s equations and models the wave behaviour of light matter interaction. Vectorial waves and multiple-scattering effect are considered in this model. Scattered field can be calculated with given distribution of the refractive index of the biological sample. Bright field images can be obtained by combining the scattered field and reflected illumination, and experimental validation is included. Insights into the utility of the full-wave multi-scattering (FWMS) solver and comparison with the conventional Born approximation based solver are presented. The model is also generalizable to the other forms of label-free coherent microscopes, such as quantitative phase microscope and dark-field microscope
In Vivo
The leaf of Elaeagnus lanceolata and Elaeagnus henryi as well as Elaeagnus pungens has been documented as an effective herb for the treatment of asthma and chronic bronchitis in traditional clinical medicine. This study was aimed at evaluating the antiasthmatic, antitussive, and expectorant activities of the water extracts from the three plants in vivo and analyzing their chemical components by HPLC-DAD. At the medium and high doses, the water extracts of three Elaeagnus leaves significantly prolonged the preconvulsive time (P < 0.01) in guinea pigs, lengthened the latent period of cough (P < 0.01) and decreased the cough frequency caused by aqueous ammonia in mice (P < 0.01), and enhanced tracheal phenol red output in mice (P < 0.01). There were no significant differences in the pharmacological actions between the three Elaeagnus leaves. Moreover, there was more similarity on overlap peaks in the range of retention time from 10 to 40 min by HPLC and many peaks that belonged to flavonoids compounds. It suggested that the main constituents of the three Elaeagnus leaves were flavonoid for the pharmacological activities. These effects were the important evidence for the traditional use of E. henryi leaf and E. lanceolata leaf as well as E. pungens to treat asthma and chronic bronchitis
Genetics of primary ovarian insufficiency: new developments and opportunities
BACKGROUND Primary ovarian insufficiency (POI) is characterized by marked heterogeneity, but with a significant genetic contribution. Identifying exact causative genes has been challenging, with many discoveries not replicated. It is timely to take stock of the field, outlining the progress made, framing the controversies and anticipating future directions in elucidating the genetics of POI. METHODS A search for original articles published up to May 2015 was performed using PubMed and Google Scholar, identifying studies on the genetic etiology of POI. Studies were included if chromosomal analysis, candidate gene screening and a genome-wide study were conducted. articles identified were restricted to English language full-text papers. RESULTS Chromosomal abnormalities have long been recognized as a frequent cause of POI, with a currently estimated prevalence of 10?13%. Using the traditional karyotype methodology, monosomy X, mosaicism, X chromosome deletions and rearrangements, X-autosome translocations, and isochromosomes have been detected. Based on candidate gene studies, single gene perturbations unequivocally having a deleterious effect in at least one population include Bone morphogenetic protein 15 (BMP15), Progesterone receptor membrane component 1 (PGRMC1), and Fragile X mental retardation 1 (FMR1) premutation on the X chromosome; Growth differentiation factor 9 (GDF9), Folliculogenesis specific bHLH transcription factor (FIGLA), Newborn ovary homeobox gene (NOBOX), Nuclear receptor subfamily 5, group A, member 1 (NR5A1) and Nanos homolog 3 (NANOS3) seem likely as well, but mostly being found in no more than 1?2% of a single population studied. Whole genome approaches have utilized genome-wide association studies (GWAS) to reveal loci not predicted on the basis of a candidate gene, but it remains difficult to locate causative genes and susceptible loci were not always replicated. Cytogenomic methods (array CGH) have identified other regions of interest but studies have not shown consistent results, the resolution of arrays has varied and replication is uncommon. Whole-exome sequencing in non-syndromic POI kindreds has only recently begun, revealing mutations in the Stromal antigen 3 (STAG3), Synaptonemal complex central element 1 (SYCE1), minichromosome maintenance complex component 8 and 9 (MCM8, MCM9) and ATP-dependent DNA helicase homolog (HFM1) genes. Given the slow progress in candidate-gene analysis and relatively small sample sizes available for GWAS, family-based whole exome and whole genome sequencing appear to be the most promising approaches for detecting potential genes responsible for POI. CONCLUSION Taken together, the cytogenetic, cytogenomic (array CGH) and exome sequencing approaches have revealed a genetic causation in ?20?25% of POI cases. Uncovering the remainder of the causative genes will be facilitated not only by whole genome approaches involving larger cohorts in multiple populations but also incorporating environmental exposures and exploring signaling pathways in intragenic and intergenic regions that point to perturbations in regulatory genes and networks
Association of basal serum testosterone levels with ovarian response and in vitro fertilization outcome
<p>Abstract</p> <p>Background</p> <p>To evaluate basal testosterone (T) levels during follicular phase of the menstrual cycle as a predictor for ovarian response and in vitro fertilization (IVF) outcome.</p> <p>Method</p> <p>We analyzed data retrospectively from hospital-based IVF center including one thousand two hundred and sixty Chinese Han women under their first IVF cycle reached the ovum pick-up stage, without polycystic ovary syndrome (PCOS) or endometriosis undergoing long IVF protocol. Patients were divided into 2 groups. Group 1: patients with diminished ovarian reserve (basal FSH >10 IU/L) (n = 187); Group 2: patients with normal ovarian reserve (basal FSH < = 10 IU/L) (n = 1073). We studied the association of basal T levels with ovarian response and IVF outcome in the two groups. Long luteal down-regulation protocol was used in all patients, that is, the gonadotropin releasing hormone agonist was administered in the midluteal phase of the previous cycle and use of recombinant FSH was started when satisfactory pituitary desensitization was achieved.</p> <p>Results</p> <p>Basal T levels were markly different between pregnant and non-pregnant women in Group 1; whereas not in Group 2. A testosterone level of 47.85 ng/dl was shown to predict pregnancy outcome with a sensitivity of 52.8% and specificity of 65.3%; and the basal T was correlated with the numbers of large follicles (> 14 mm) on HCG day in Group 1. Significantly negative correlations were observed between basal T, days of stimulation and total dose of gonadotropins after adjusting for confounding factors in both groups.</p> <p>Conclusion</p> <p>In women with diminished ovarian reserve, basal T level was a predictor for the number of large follicles on HCG day and pregnancy outcome; but could not in those with normal serum FSH. Basal T levels were associated with both days of stimulation and total dose of gonadotropins, indicating that lower level of T might relate with potential ovarian poor response.</p
DualVD: An Adaptive Dual Encoding Model for Deep Visual Understanding in Visual Dialogue
Different from Visual Question Answering task that requires to answer only
one question about an image, Visual Dialogue involves multiple questions which
cover a broad range of visual content that could be related to any objects,
relationships or semantics. The key challenge in Visual Dialogue task is thus
to learn a more comprehensive and semantic-rich image representation which may
have adaptive attentions on the image for variant questions. In this research,
we propose a novel model to depict an image from both visual and semantic
perspectives. Specifically, the visual view helps capture the appearance-level
information, including objects and their relationships, while the semantic view
enables the agent to understand high-level visual semantics from the whole
image to the local regions. Futhermore, on top of such multi-view image
features, we propose a feature selection framework which is able to adaptively
capture question-relevant information hierarchically in fine-grained level. The
proposed method achieved state-of-the-art results on benchmark Visual Dialogue
datasets. More importantly, we can tell which modality (visual or semantic) has
more contribution in answering the current question by visualizing the gate
values. It gives us insights in understanding of human cognition in Visual
Dialogue.Comment: Accepted by the Thirty-Fourth AAAI Conference on Artificial
Intelligence (AAAI-2020
Bright solitons in a spin-orbit-coupled dipolar Bose-Einstein condensate trapped within a double-lattice
By effectively controlling the dipole-dipole interaction, we investigate the
characteristics of the ground state of bright solitons in a spin-orbit coupled
dipolar Bose-Einstein condensate. The dipolar atoms are trapped within a
double-lattice which consists of a linear and a nonlinear lattice. We derive
the motion equations of the different spin components, taking the controlling
mechanisms of the diolpe-dipole interaction into account. An analytical
expression of dipole-dipole interaction is derived. By adjusting the dipole
polarization angle, the dipole interaction can be adjusted from attraction to
repulsion. On this basis, we study the generation and manipulation of the
bright solitons using both the analytical variational method and numerical
imaginary time evolution. The stability of the bright solitons is also analyzed
and we map out the stability phase diagram. By adjusting the long-range
dipole-dipole interaction, one can achieve manipulation of bright solitons in
all aspects, including the existence, width, nodes, and stability. Considering
the complexity of our system, our results will have enormous potential
applications in quantum simulation of complex systems
Novel NR5A1 Missense Mutation in Premature Ovarian Failure: Detection in Han Chinese Indicates Causation in Different Ethnic Groups
Background
The etiology of most premature ovarian failure (POF) cases is usually elusive. Although genetic causes clearly exist and a likely susceptible region of 8q22.3 has been discovered, no predominant explanation exists for POF. More recently, evidences have indicated that mutations in NR5A1 gene could be causative for POF. We therefore screened for mutations in the NR5A1 gene in a large cohort of Chinese women with non-syndromic POF. Methods
Mutation screening of NR5A1 gene was performed in 400 Han Chinese women with well-defined 46,XX idiopathic non-syndromic POF and 400 controls. Subsequently, functional characterization of the novel mutation identified was evaluated in vitro. Results
A novel heterozygous missense mutation [c.13T\u3eG (p.Tyr5Asp)] in NR5A1 was identified in 1 of 384 patients (0.26%). This mutation impaired transcriptional activation on Amh, Inhibin-a, Cyp11a1and Cyp19a1 gene, as shown by transactivation assays. However, no dominant negative effect was observed, nor was there impact on protein expression and nuclear localization. Conclusions
This novel mutation p.Tyr5Asp, in a novel non-domain region, is presumed to result in haploinsufficiency. Irrespectively, perturbation in NR5A1 is not a common explanation for POF in Chinese
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