528 research outputs found

    Single and binary protein electroultrafiltration using poly(vinyl-alcohol)-carbon nanotube (PVA-CNT) composite membranes.

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    Electrically conductive composite ultrafiltration membranes composed of carbon nanotubes have exhibited efficient fouling inhibition in wastewater treatment applications. In the current study, poly(vinyl-alcohol)-carbon nanotube membranes were applied to fed batch crossflow electroultrafiltration of dilute (0.1 g/L of each species) single and binary protein solutions of α-lactalbumin and hen egg-white lysozyme at pH 7.4, 4 mM ionic strength, and 1 psi. Electroultrafiltration using the poly(vinyl-alcohol)-carbon nanotube composite membranes yielded temporary enhancements in sieving for single protein filtration and in selectivity for binary protein separation compared to ultrafiltration using the unmodified PS-35 membranes. Assessment of membrane fouling based on permeate flux, zeta potential measurements, and scanning electron microscopy visualization of the conditioned membranes indicated significant resulting protein adsorption and aggregation which limited the duration of improvement during electroultrafiltration with an applied cathodic potential of -4.6 V (vs. Ag/AgCl). These results imply that appropriate optimization of electroultrafiltration using carbon nanotube-deposited polymeric membranes may provide substantial short-term improvements in binary protein separations

    Structurally Ordered Mesoporous Carbon Nanoparticles as Transmembrane Delivery Vehicle in Human Cancer Cells

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    A structurally ordered, CMK-1 type mesoporous carbon nanoparticle (MCN) material was successfully synthesized by using a MCM-48 type mesoporous silica nanoparticle as template. The structure of MCN was analyzed by a series of different techniques, including the scanning and transmission electron microscopy, powder X-ray diffraction, and N2 sorption analysis. To the best of our knowledge, no study has been reported prior to our investigation on the utilization of these structurally ordered mesoporous carbon nanoparticles for the delivery of membrane impermeable chemical agents inside of eukaryotic cells. The cellular uptake efficiency and biocompatibility of MCN with human cervical cancer cells (HeLa) were investigated. Our results show that the inhibitory concentration (IC50) value of MCN is very high (\u3e50 μg/mL per million cells) indicating that MCN is fairly biocompatible in vitro. Also, a membrane impermeable fluorescence dye, Fura-2, was loaded to the mesoporous matrix of MCN. We demonstrated that the MCN material could indeed serve as a transmembrane carrier for delivering Fura-2 through the cell membrane to release these molecules inside of live HeLa cells. We envision that further developments of this MCN material will lead to a new generation of nanodevices for transmembrane delivery and intracellular release applications

    Are Preoperative Kattan and Stephenson Nomograms Predicting Biochemical Recurrence after Radical Prostatectomy Applicable in the Chinese Population?

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    Purpose. Kattan and Stephenson nomograms are based on the outcomes of patients with prostate cancer recruited in the USA, but their applicability to Chinese patients is yet to be validated. We aim at studying the predictive accuracy of these nomograms in the Chinese population. Patients and Methods. A total of 408 patients who underwent laparoscopic or open radical resection of prostate from 1995 to 2009 were recruited. The preoperative clinical parameters of these patients were collected, and they were followed up regularly with PSA monitored. Biochemical recurrence was defined as two or more consecutive PSA levels >0.4 ng/mL after radical resection of prostate or secondary cancer treatment. Results. The overall observed 5-year and 10-year biochemical recurrence-free survival rates were 68.3% and 59.8%, which was similar to the predicted values by the Kattan and Stephenson nomograms, respectively. The results of our study achieved a good concordance with both nomograms (Kattan: 5-years, 0.64; Stephenson: 5-years, 0.62, 10-years, 0.71). Conclusions. The incidence of prostate cancer in Hong Kong is increasing together with the patients’ awareness of this disease. Despite the fact that Kattan nomograms were derived from the western population, it has been validated in our study to be useful in Chinese patients as well

    The C. Elegans Heterochronic Gene lin-46 Affects Developmental Timing at Two Larval Stages and Encodes a Relative of the Scaffolding Protein Gephyrin

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    The succession of developmental events in the C. elegans larva is governed by the heterochronic genes. When mutated, these genes cause either precocious or retarded developmental phenotypes, in which stage-specific patterns of cell division and differentiation are either skipped or reiterated, respectively. We identified a new heterochronic gene, lin-46, from mutations that suppress the precocious phenotypes caused by mutations in the heterochronic genes lin-14 and lin-28. lin-46 mutants on their own display retarded phenotypes in which cell division patterns are reiterated and differentiation is prevented in certain cell lineages. Our analysis indicates that lin-46 acts at a step immediately downstream of lin-28, affecting both the regulation of the heterochronic gene pathway and execution of stage-specific developmental events at two stages: the third larval stage and adult. We also show that lin-46 is required prior to the third stage for normal adult cell fates, suggesting that it acts once to control fates at both stages, and that it affects adult fates through the let-7 branch of the heterochronic pathway. Interestingly, lin-46 encodes a protein homologous to MoeA of bacteria and the C-terminal domain of mammalian gephyrin, a multifunctional scaffolding protein. Our findings suggest that the LIN-46 protein acts as a scaffold for a multiprotein assembly that controls developmental timing, and expand the known roles of gephyrin-related proteins to development

    Anomalous Scaling of Structure Functions and Dynamic Constraints on Turbulence Simulations

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    The connection between anomalous scaling of structure functions (intermittency) and numerical methods for turbulence simulations is discussed. It is argued that the computational work for direct numerical simulations (DNS) of fully developed turbulence increases as Re4Re^{4}, and not as Re3Re^{3} expected from Kolmogorov's theory, where ReRe is a large-scale Reynolds number. Various relations for the moments of acceleration and velocity derivatives are derived. An infinite set of exact constraints on dynamically consistent subgrid models for Large Eddy Simulations (LES) is derived from the Navier-Stokes equations, and some problems of principle associated with existing LES models are highlighted.Comment: 18 page

    Transcriptomic Comparison of Human Peripartum and Dilated Cardiomyopathy Identifies Differences in Key Disease Pathways

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    Peripartum cardiomyopathy (PPCM) is a rare form of acute onset heart failure that presents in otherwise healthy pregnant women around the time of delivery. While most of these women respond to early intervention, about 20% progress to end-stage heart failure that symptomatically resembles dilated cardiomyopathy (DCM). In this study, we examined two independent RNAseq datasets from the left ventricle of end-stage PPCM patients and compared gene expression profiles to female DCM and non-failing donors. Differential gene expression, enrichment analysis and cellular deconvolution were performed to identify key processes in disease pathology. PPCM and DCM display similar enrichment in metabolic pathways and extracellular matrix remodeling suggesting these are similar processes across end-stage systolic heart failure. Genes involved in golgi vesicles biogenesis and budding were enriched in PPCM left ventricles compared to healthy donors but were not found in DCM. Furthermore, changes in immune cell populations are evident in PPCM but to a lesser extent compared to DCM, where the latter is associated with pronounced pro-inflammatory and cytotoxic T cell activity. This study reveals several pathways that are common to end-stage heart failure but also identifies potential targets of disease that may be unique to PPCM and DCM.</p

    Precise Temporal Action Localization by Evolving Temporal Proposals

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    Locating actions in long untrimmed videos has been a challenging problem in video content analysis. The performances of existing action localization approaches remain unsatisfactory in precisely determining the beginning and the end of an action. Imitating the human perception procedure with observations and refinements, we propose a novel three-phase action localization framework. Our framework is embedded with an Actionness Network to generate initial proposals through frame-wise similarity grouping, and then a Refinement Network to conduct boundary adjustment on these proposals. Finally, the refined proposals are sent to a Localization Network for further fine-grained location regression. The whole process can be deemed as multi-stage refinement using a novel non-local pyramid feature under various temporal granularities. We evaluate our framework on THUMOS14 benchmark and obtain a significant improvement over the state-of-the-arts approaches. Specifically, the performance gain is remarkable under precise localization with high IoU thresholds. Our proposed framework achieves mAP@IoU=0.5 of 34.2%

    Synovial fluid leukocyte apoptosis is inhibited in patients with very early rheumatoid arthritis

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    Synovial leukocyte apoptosis is inhibited in established rheumatoid arthritis (RA). In contrast, high levels of leukocyte apoptosis are seen in self-limiting crystal arthritis. The phase in the development of RA at which the inhibition of leukocyte apoptosis is first apparent, and the relationship between leukocyte apoptosis in early RA and other early arthritides, has not been defined. We measured synovial fluid leukocyte apoptosis in very early arthritis and related this to clinical outcome. Synovial fluid was obtained at presentation from 81 patients with synovitis of ≤ 3 months duration. The percentages of apoptotic neutrophils and lymphocytes were assessed on cytospin preparations. Patients were assigned to diagnostic groups after 18 months follow-up. The relationship between leukocyte apoptosis and patient outcome was assessed. Patients with early RA had significantly lower levels of neutrophil apoptosis than patients who developed non-RA persistent arthritis and those with a resolving disease course. Similarly, lymphocyte apoptosis was absent in patients with early RA whereas it was seen in patients with other early arthritides. The inhibition of synovial fluid leukocyte apoptosis in the earliest clinically apparent phase of RA distinguishes this from other early arthritides. The mechanisms for this inhibition may relate to the high levels of anti-apoptotic cytokines found in the early rheumatoid joint (e.g. IL-2, IL-4, IL-15 GMCSF, GCSF). It is likely that this process contributes to an accumulation of leukocytes in the early rheumatoid lesion and is involved in the development of the microenvironment required for persistent RA

    PLZF-expressing CD4 T cells show the characteristics of terminally differentiated effector memory CD4 T cells in humans

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    In humans, promyelocytic leukaemia zinc finger (PLZF)+CD161+CD4 T cells develop in the fetal thymus [1] but these cells were not detectable in thymi obtained from children (11 days to 5.5 years) (Fig. 1A). However, we found PLZF+CD4 T cells within CD45RA+RO+CD4 T cells from tonsils and spleens but rarely in blood (Fig. 1B, left panel and 1C; Supporting Information Fig. 1A and B). PLZF expression was also confirmed by mRNA analysis in these cells from tonsils (Fig. 1B, right panel). CD8 T cells had a very low frequency of CD45RA+RO+ cells compared to CD4 T cells and these cells did not express PLZF (Fig. 1B). We also validated that CD45RA+RO+CD4 T cells are not mucosalassociated invariant T cells [2] (data not shown). PLZF-expressing NKT cells were excluded from all our analyses by CD1d- Tetramer staining (Supporting Information Fig. 2
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