994 resultados para Isolation


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Gonadal development is an ideal model to study organogenesis because a variety of developmental processes can be studied during the differentiation of the bipotential primordium into testis or ovary. To better understand this process, Representational Difference Analysis of cDNA was used to identify genes that are differentially expressed in mouse gonads at 13.5 days post-coitus. The analysis led to the identification of three testis specific genes and a sequence that was only expressed in the ovary. The male genes identified: renin, Col9a3, and a novel gene termed tescalcin had patterns of expression that suggested a role in testis determination. ^ Studies of the tescalcin gene revealed that it is organized into eight exons and seven introns. The gene was located at 64 cM in mouse chromosome 5, where it spans approximately 35 Kb. Three mRNA variants resulting from alternative splicing of intron 5 were identified in mouse tissues. Gel mobility shift assays demonstrated that Sp1 and Sp3 from Y-1, msc-1, and MIN-6 cells nuclear extracts bind the GC-boxes within the tescalcin proximal promoter. Bisulfite sequencing analysis of tescalcin CpG island revealed that it is differentially methylated in male and female mouse embryonic gonads, and that hypermethylation of this region represses expression of tescalcin in the β-TC3 cell line. ^ The major tescalcin mRNA encodes a protein with 214 amino acids that contains a consensus EF-hand Ca2+-binding domain and an N-myristoylation motif. The amino acid sequence of tescalcin is highly conserved among various species, and it showed the highest homology with calcineurin B homologous proteins 1 and 2, and calcineurin B. Western blot analysis using antibodies generated against the tescalcin protein confirmed its presence in specific mouse tissues and cell lines. Immunohistochemical analysis of mouse embryos confirmed the pattern of expression of tescalcin mRNA in fetal testis. Using pull-down assays, glyceraidehydes-3-phosphate dehydrogenase was identified as an interacting and potential functional partner of tescalcin. ^ The identification and characterization of tescalcin as a novel embryonic testicular marker will contribute to the elucidation of the genetic pathways involved in testis development and likely to the understanding of pathological conditions such as sex reversal and infertility. ^

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In isolation and characterization studies, expression level U1 and U2 snRNA isoforms were obtained from the 5th instar larval stage silk gland (SG). The DNA content of the SG cells is approximately 200,000-fold higher compared to the usual (2N) somatic cells of B. mori due to endoreduplication. In this study, the existence of U1 and U2 snRNA isoforms in the SG of the organism is investigated. Bombyx mori U1 and U2-specific RT-PCR libraries from the silk gland were generated. Five U1 and eight U2 isoforms were isolated and characterized. Nucleotide differences, structural alterations, as well as protein and RNA interaction sites were analyzed in these variants. For the U1 snRNA variants, they were compared to the previously reported BmN isoforms. In all these U-snRNA variants, polymorphic sites do not predominate at the core of known functional sequences, which were interspecifically conserved. Variant sites and inter-species differences are located in moderately conserved regions. Free energy (ΔG) values for the entire U1 and U2 snRNA secondary structures and for the individual stem/loops domains of the isoforms were generated and compared to determine their structural stability. This will be the first time that U1 and U2 variants are shown specific for a development stage (larval) other than embryonic or adult. ^ Using phylogenetic analysis, evolutionary trees were generated for the U1 and U2 snRNAs using animal, plant, protista and fungal species. The resulting trees were boostrapped for robustness and rooted with the self-splicing RNA group II intron sequence from the cyanobacterium Calothrix. Using phylogenetic analyses, possible structural and functional evolutionary interdependence between the U1 and U2 snRNAs was investigated. ^

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Funding This work was supported by the HADEEP projects, funded by the Nippon Foundation, Japan (2009765188), the Natural Environmental Research Council, UK (NE/E007171/1) and the Total Foundation, France. We acknowledge additional support from the Marine Alliance for Science and Technology for Scotland (MASTS) funded by the Scottish Funding Council (Ref: HR09011) and contributing institutions. We also acknowledge support from the Leverhulme Trust to SBP. Additional sea time was supported by NIWA’s ‘Impact of Resource Use on Vulnerable Deep-Sea Communities’ project (CO1_0906)

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Cancer comprises a collection of diseases, all of which begin with abnormal tissue growth from various stimuli, including (but not limited to): heredity, genetic mutation, exposure to harmful substances, radiation as well as poor dieting and lack of exercise. The early detection of cancer is vital to providing life-saving, therapeutic intervention. However, current methods for detection (e.g., tissue biopsy, endoscopy and medical imaging) often suffer from low patient compliance and an elevated risk of complications in elderly patients. As such, many are looking to “liquid biopsies” for clues into presence and status of cancer due to its minimal invasiveness and ability to provide rich information about the native tumor. In such liquid biopsies, peripheral blood is drawn from patients and is screened for key biomarkers, chiefly circulating tumor cells (CTCs). Capturing, enumerating and analyzing the genetic and metabolomic characteristics of these CTCs may hold the key for guiding doctors to better understand the source of cancer at an earlier stage for more efficacious disease management.

The isolation of CTCs from whole blood, however, remains a significant challenge due to their (i) low abundance, (ii) lack of a universal surface marker and (iii) epithelial-mesenchymal transition that down-regulates common surface markers (e.g., EpCAM), reducing their likelihood of detection via positive selection assays. These factors potentiate the need for an improved cell isolation strategy that can collect CTCs via both positive and negative selection modalities as to avoid the reliance on a single marker, or set of markers, for more accurate enumeration and diagnosis.

The technologies proposed herein offer a unique set of strategies to focus, sort and template cells in three independent microfluidic modules. The first module exploits ultrasonic standing waves and a class of elastomeric particles for the rapid and discriminate sequestration of cells. This type of cell handling holds promise not only in sorting, but also in the isolation of soluble markers from biofluids. The second module contains components to focus (i.e., arrange) cells via forces from acoustic standing waves and separate cells in a high throughput fashion via free-flow magnetophoresis. The third module uses a printed array of micromagnets to capture magnetically labeled cells into well-defined compartments, enabling on-chip staining and single cell analysis. These technologies can operate in standalone formats, or can be adapted to operate with established analytical technologies, such as flow cytometry. A key advantage of these innovations is their ability to process erythrocyte-lysed blood in a rapid (and thus high throughput) fashion. They can process fluids at a variety of concentrations and flow rates, target cells with various immunophenotypes and sort cells via positive (and potentially negative) selection. These technologies are chip-based, fabricated using standard clean room equipment, towards a disposable clinical tool. With further optimization in design and performance, these technologies might aid in the early detection, and potentially treatment, of cancer and various other physical ailments.

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Rolling Isolation Systems provide a simple and effective means for protecting components from horizontal floor vibrations. In these systems a platform rolls on four steel balls which, in turn, rest within shallow bowls. The trajectories of the balls is uniquely determined by the horizontal and rotational velocity components of the rolling platform, and thus provides nonholonomic constraints. In general, the bowls are not parabolic, so the potential energy function of this system is not quadratic. This thesis presents the application of Gauss's Principle of Least Constraint to the modeling of rolling isolation platforms. The equations of motion are described in terms of a redundant set of constrained coordinates. Coordinate accelerations are uniquely determined at any point in time via Gauss's Principle by solving a linearly constrained quadratic minimization. In the absence of any modeled damping, the equations of motion conserve energy. This mathematical model is then used to find the bowl profile that minimizes response acceleration subject to displacement constraint.

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Ageing of the population is a worldwide phenomenon. Numerous ICT-based solutions have been developed for elderly care but mainly connected to the physiological and nursing aspects in services for the elderly. Social work is a profession that should pay attention to the comprehensive wellbeing and social needs of the elderly. Many people experience loneliness and depression in their old age, either as a result of living alone or due to a lack of close family ties and reduced connections with their culture of origin, which results in an inability to participate actively in community activities (Singh & Misra, 2009). Participation in society would enhance the quality of life. With the development of information technology, the use of technology in social work practice has risen dramatically. The aim of this literature review is to map out the state of the art of knowledge about the usage of ICT in elderly care and to figure out research-based knowledge about the usability of ICT for the prevention of loneliness and social isolation of elderly people. The data for the current research comes from the core collection of the Web of Science and the data searching was performed using Boolean? The searching resulted in 216 published English articles. After going through the topics and abstracts, 34 articles were selected for the data analysis that is based on a multi approach framework. The analysis of the research approach is categorized according to some aspects of using ICT by older adults from the adoption of ICT to the impact of usage, and the social services for them. This literature review focused on the function of communication by excluding the applications that mainly relate to physical nursing. The results show that the so-called ‘digital divide’ still exists, but the older adults have the willingness to learn and utilise ICT in daily life, especially for communication. The data shows that the usage of ICT can prevent the loneliness and social isolation of older adults, and they are eager for technical support in using ICT. The results of data analysis on theoretical frames and concepts show that this research field applies different theoretical frames from various scientific fields, while a social work approach is lacking. However, a synergic frame of applied theories will be suggested from the perspective of social work.

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Objective
Scant evidence is available on the discordance between loneliness and social isolation among older adults. We aimed to investigate this discordance and any health implications that it may have.

Method
Using nationally representative datasets from ageing cohorts in Ireland (TILDA) and England (ELSA), we created a metric of discordance between loneliness and social isolation, to which we refer as Social Asymmetry. This metric was the categorised difference between standardised scores on a scale of loneliness and a scale of social isolation, giving categories of: Concordantly Lonely and Isolated, Discordant: Robust to Loneliness, or Discordant: Susceptible to Loneliness. We used regression and multilevel modelling to identify potential relationships between Social Asymmetry and cognitive outcomes.

Results
Social Asymmetry predicted cognitive outcomes cross-sectionally and at a two-year follow-up, such that Discordant: Robust to Loneliness individuals were superior performers, but we failed to find evidence for Social Asymmetry as a predictor of cognitive trajectory over time.

Conclusions
We present a new metric and preliminary evidence of a relationship with clinical outcomes. Further research validating this metric in different populations, and evaluating its relationship with other outcomes, is warranted.

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The racemic tertiary cathinones N,N-dimethylcathinone (1), N,N-diethylcathinone (2) and 2-(1-pyrrolidinyl)-propiophenone (3) have been prepared in reasonable yield and characterized using NMR and mass spectroscopy. HPLC indicates that these compounds are isolated as the anticipated racemic mixture. These can then be co-crystallized with (+)-O,O′-di-p-toluoyl-d-tartaric, (+)-O,O′-dibenzoyl-d-tartaric and (-)-O,O′-dibenzoyl-l-tartaric acids giving the single enantiomers S and R respectively of 1, 2 and 3, in the presence of sodium hydroxide through a dynamic kinetic resolution. X-ray structural determination confirmed the enantioselectivity. The free amines could be obtained following basification and extraction. In methanol these are reasonably stable for the period of several hours, and their identity was confirmed by HPLC and CD spectroscopy.

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This paper presents a novel high symmetry balun which significantly improves the performance of dipole-based dual-polarized antennas. The new balun structure provides enhanced differential capability leading to high performance in terms of port-to-port isolation and far-field cross polarization. An example antenna using this balun is proposed. The simulated results show 53.5% of fractional bandwidth within the band 1.71−2.96 GHz (VSWR<1.5) and port-to-port isolation >59 dB. The radiation characteristic shows around 9 dBi of gain and far-field cross polarization <−48 dBi over the entire bandwidth. The detailed balun functioning and full antenna measurements will be presented during the conference. Performance comparison with similar structures will be also provided.

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B7-H4 (VTCN1, B7x, B7s) is an inhibitory modulator of T-cell response implicated in antigen tolerization. As such, B7-H4 is an immune checkpoint of potential therapeutic interest. To generate anti-B7-H4 targeting reagents, we isolated antibodies by differential cell screening of a yeast-display library of recombinant antibodies (scFvs) derived from ovarian cancer patients and we screened for functional scFvs capable to interfere with B7-H4-mediated inhibition of antitumor responses. We found one antibody binding to B7-H4 that could restore antitumor T cell responses. This chapter gives an overview of the methods we developed to isolate a functional anti-B7-H4 antibody fragment.

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This article reports the initial findings from the evaluation of four creative arts projects involving groups of older people living in a rural community. The purpose of the projects was to reduce social isolation among participants through providing direct access to arts and social activities. The view was that these activities would improve life skills and independence, increase levels of activity and improve the health, wellbeing and quality of life of participants. Evaluation of these projects demonstrated increased levels of self-worth and self-esteem among participants, and many of the older people involved agreed that they had made new friends while having the opportunity to try out a new activity.

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v. 46, n. 2, p. 149-158, apr./jun. 2016.

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Thesis (Ph.D.)--University of Washington, 2016-08