162 research outputs found

    Highly Transparent, Self-cleaning, and Antireflective Nanoparticle Coatings

    Get PDF
    Current solar panel technologies require a sheet of glass to serve as both mechanical support and to protect the cells from the environment. The reflection from the glass sheet can reflect up to 8% of the incident light, reducing the power output of the panel. Antireflective coatings can be used to allow more light to enter the panel to be converted into usable electricity. However, no solid thin film materials exhibit a low enough index of refraction to serve as antireflective coatings for common solar glass. The main goal of this research was to investigate the self-cleaning, antifogging, and antireflective behavior of low index of refraction silica nanoparticle films, with an ultimate goal to develop a method to deposit these films on glass substrates from aqueous solutions. The optical, wetting, and self-cleaning ability of these films was evaluated at a laboratory scale. It was determined that the film performance could be significantly improved by utilizing a polyvinylpyrrolidone (PVP) adhesion layer during the deposition process. Using this method, the solar weighted transmittance of glass was improved to 97.4%, with peak transmittance of 99.5%, using a double sided coating. The short-circuit current and conversion efficiency of silicon solar cells was improved by a relative 4.4% over an equivalent cell packaged behind uncoated glass. This represents 50% recovery of the losses associated with packaging. Dual-layer antireflective coatings for both silicon and gallium arsenide solar cells using the silica nanoparticle coating were also created. An average increase of 28% in the short-circuit current and 32% relative improvement in device efficiency was achieved with silicon devices. The average conversion efficiency of the planar silicon cells was increased from 10.6% to 14% by addition of the coating. In summary, the experimental study of the optical properties and surface morphology of silica nanoparticle films deposited with a PVP adhesion layer demonstrated the potential of these films as optical coatings and functional self-cleaning and antifogging surfaces. The characterization of these silica nanoparticle films provided a fundamental understanding of the relationship between the optical and wetting properties of the nanoparticle coating and the morphology of the film

    The Evaluation of Mefloquine Drug Repurposing on Acute Myeloid Leukemia

    Get PDF
    The aim of this study is to observe cell proliferation, cell viability, apoptosis, and autophagy on acute myeloid leukemia (AML) cell lines, NB4 and U937, with the drug repurposing of mefloquine (MQ). Methods such as the 3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay and trypan blue staining have shown a decrease in live cells with high concentrations of mefloquine. Using their average perspective IC50 values of MQ concentration, Western blotting was applied by means of apoptosis and autophagy markers to determine if the induction of apoptosis and inhibition of autophagy was present in MQ-treated AML cells. The experiment will be continued with more cell lines, drugs, and other means of protocol in order to contribute to cancer therapy.https://scholarscompass.vcu.edu/uresposters/1285/thumbnail.jp

    Stochastic hypothesis of transition from inborn neutropenia to AML: interactions of cell population dynamics and population genetics

    Get PDF
    We present a stochastic model of driver mutations in the transition from severe congenital neutropenia to myelodysplastic syndrome to acute myeloid leukemia (AML). The model has the form of a multitype branching process.We derive equations for the distributions of the times to consecutive driver mutations and set up simulations involving a range of hypotheses regarding acceleration of the mutation rates in successive mutant clones. Our model reproduces the clinical distribution of times at diagnosis of secondary AML. Surprisingly, within the framework of our assumptions, stochasticity of the mutation process is incapable of explaining the spread of times at diagnosis of AML in this case; it is necessary to additionally assume a wide spread of proliferative parameters among disease cases. This finding is unexpected but generally consistent with the wide heterogeneity of characteristics of human cancers

    Zebrafish Model of MLL-Rearranged Acute Myeloid Leukemia

    Get PDF
    Background: Acute myeloid leukemia (AML) is the second most common type of leukemia. Standard treatment includes chemotherapy as well as stem cell transplantation, but for aging patients and those with impaired immune function these rigorous therapies are not always possible. Furthermore, AML patients harboring a chromosomal rearrangement involving Multiple Lineage Leukemia (MLL) exhibit far worse prognoses than patients without. Given these circumstances new therapies must be developed. Methods: Danio rerio (zebrafish) has emerged as a powerful model organism for investigating human blood malignancies due to the conservation of hematopoiesis between humans and zebrafish. We developed a transient transgenic model exhibiting AML characteristics by microinjecting single-cell zebrafish embryos with a tissue specific MLL-ENL expression construct. Results: We found that the expression of MLL-ENL induced a clustered expansion of MLL+ and pu.1+ myeloid cells on the yolk sac at 48 and 72 hours post fertilization (hpf). To characterize our transient AML model, we treated MLL-ENL expressing embryos with either one of or a combination of two drugs that are currently being used in human AML drug trials, Venetoclax and Flavopiridol. We found that treatment with either drug reduced the myeloid expansion induced by the expression of MLL-ENL, and that co-treatment reduced the observed myeloid expansion even further. Conclusions: Although further analysis is required, these data suggest that we successfully developed a transient transgenic AML model in zebrafish. Furthermore, these data suggest that Venetoclax and Flavopiridol co-treatment could yield better outcomes for AML patients than treatment with either drug individually.https://scholarscompass.vcu.edu/gradposters/1112/thumbnail.jp

    Ex vivo expansion of megakaryocyte precursors from umbilical cord blood CD34+ cells in a closed liquid culture system

    Get PDF
    AbstractUmbilical cord blood (UCB) provides a rich source of stem cells for transplantation after myeloablative therapy. One major disadvantage of UCB transplantation is delayed platelet engraftment. We propose to hasten platelet engraftment by expanding the number of megakaryocyte (MK) precursors (CD34/CD41 cells) through cytokine stimulation within a closed, pre-clinical liquid culture system. Clinical engraftment data suggest a 5- to 10-fold increase in MK precursors in a UCB unit can accelerate platelet engraftment, so this was our goal. Thirteen UCB samples from full-term births were Ficoll-separated and frozen for subsequent use. On thawing, the mononuclear cell population was positively selected for CD34+ expression. The cells were cultured in gas-permeable Teflon-coated bags in serum-free medium containing the following cytokines: recombinant human interleukin-3, recombinant human Flt3 ligand, recombinant human stem cell factor, and recombinant human thrombopoietin. MK lineage cell expansion was assessed using mononuclear cell count and flow cytometry (CD34/41, CD41, CD34/61, and CD61 expression) on days 7, 11, and 14. Optimal expansion of CD34/41 and CD41 cells was observed at day 11, with a median 6-fold and 33-fold increase in the starting cell doses, respectively. CD34/61 and CD61 cell expansion at day 11 was 7-fold and 14-fold, respectively. MK precursors can be successfully expanded from CD34+ UCB cells in a closed liquid culture system using interleukin-3, recombinant human Flt3 ligand, recombinant human stem cell factor, and recombinant human thrombopoietin to a level that should have a clinical impact in the transplantation setting. Our ex vivo expansion technique needs to be further optimized before it can be used in a pilot UCB transplantation trial. © 2003 American Society for Blood and Marrow TransplantationBiology of Blood and Marrow Transplantation 9:151-156 (2003

    Relationships Between Problem-Gambling Severity and Psychopathology as Moderated by Income

    Get PDF
    Background and aims Problem and pathological gambling have been associated with elevated rates of both Axis-I and Axis-II psychiatric disorders. Although both problem gambling and psychiatric disorders have been reported as being more prevalent among lower income vs. middle/higher income groups, how income might moderate the relationship between problem-gambling severity and psychopathology is incompletely understood. To examine the associations between problem-gambling severity and psychopathology in lower income and middle/higher income groups. Methods Data from the first wave of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) (n = 43,093) were analyzed in adjusted logistic regression models to investigate the relationships between problem-gambling severity and psychiatric disorders within and across income groups. Results Greater problem-gambling severity was associated with increased odds of multiple psychiatric disorders for both lower income and middle/higher income groups. Income moderated the association between problem/pathological gambling and alcohol abuse/dependence, with a stronger association seen among middle/higher income respondents than among lower income respondents. Discussion and conclusions The findings that problem-gambling severity is related to psychopathology across income groups suggest a need for public health initiatives across social strata to reduce the impact that problem/pathological gambling may have in relation to psychopathology. Middle/higher income populations, perhaps owing to the availability of more “disposable income,” may be at greater risk for co-occurring gambling and alcohol-use psychopathology and may benefit preferentially from interventions targeting both gambling and alcohol use

    Recent Advances in the Treatment of Opioid Use Disorder

    Get PDF
    PURPOSE OF REVIEW: Opioid use disorder (OUD) remains a national epidemic with an immense consequence to the United States\u27 healthcare system. Current therapeutic options are limited by adverse effects and limited efficacy. RECENT FINDINGS: Recent advances in therapeutic options for OUD have shown promise in the fight against this ongoing health crisis. Modifications to approved medication-assisted treatment (MAT) include office-based methadone maintenance, implantable and monthly injectable buprenorphine, and an extended-release injectable naltrexone. Therapies under investigation include various strategies such as heroin vaccines, gene-targeted therapy, and biased agonism at the G protein-coupled receptor (GPCR), but several pharmacologic, clinical, and practical barriers limit these treatments\u27 market viability. This manuscript provides a comprehensive review of the current literature regarding recent innovations in OUD treatment

    Decision Criteria for Large Vessel Occlusion Using Transcranial Doppler Waveform Morphology

    Get PDF
    Background: The current lack of effective tools for prehospital identification of Large Vessel Occlusion (LVO) represents a significant barrier to efficient triage of stroke patients and detriment to treatment efficacy. The validation of objective Transcranial Doppler (TCD) metrics for LVO detection could provide first responders with requisite tools for informing stroke transfer decisions, dramatically improving patient care.Objective: To compare the diagnostic efficacy of two such candidate metrics: Velocity Asymmetry Index (VAI), which quantifies disparity of blood flow velocity across the cerebral hemispheres, and Velocity Curvature Index (VCI), a recently proposed TCD morphological biomarker. Additionally, we investigate a simple decision tree combining both metrics.Methods: We retrospectively compare accuracy/sensitivity/specificity (ACC/SEN/SPE) of each method (relative to standard CT-Angiography) in detecting LVO in a population of 66 subjects presenting with stroke symptoms (33 with CTA-confirmed LVO), enrolled consecutively at Erlanger Southeast Regional Stroke Center in Chattanooga, TN.Results: Individual VCI and VAI metrics demonstrated robust performance, with area under receiver operating characteristic curve (ROC-AUC) of 94% and 88%, respectively. Additionally, leave-one-out cross-validation at optimal identified thresholds resulted in 88% ACC (88% SEN) for VCI, vs. 79% ACC (76% SEN) for VAI. When combined, the resultant decision tree achieved 91% ACC (94% SEN).Discussion: We conclude VCI to be superior to VAI for LVO detection, and provide evidence that simple decision criteria incorporating both metrics may further optimize.Performance: Our results suggest that machine-learning approaches to TCD morphological analysis may soon enable robust prehospital LVO identification.Registration: Was not required for this feasibility study

    Expanding the scope of drug repurposing in pediatrics: The Children's Pharmacy Collaborative™

    Get PDF
    Drug repurposing is the use of “old” drugs for new indications, avoiding the need for time- and cost-intensive toxicity studies. This approach should be particularly attractive for pediatrics, but its use in this population has been limited. One obstacle has been the lack of a comprehensive database of drugs for which there already is at least one indication in children. We describe the development of The Children’s Pharmacy Collaborative™, which should grow over time, serve as a resource for professionals and families, and stimulate drug repurposing efforts for a range of pediatric disorders

    Dasatinib inhibits the growth of molecularly heterogeneous myeloid leukemias.

    Get PDF
    PURPOSE: Dasatinib is a dual Src/Abl inhibitor recently approved for Bcr-Abl+ leukemias with resistance or intolerance to prior therapy. Because Src kinases contribute to multiple blood cell functions by triggering a variety of signaling pathways, we hypothesized that their molecular targeting might lead to growth inhibition in acute myeloid leukemia (AML). EXPERIMENTAL DESIGN: We studied growth factor-dependent and growth factor-independent leukemic cell lines, including three cell lines expressing mutants of receptor tyrosine kinases (Flt3 or c-Kit) as well as primary AML blasts for responsiveness to dasatinib. RESULTS: Dasatinib resulted in the inhibition of Src family kinases in all cell lines and blast cells at approximately 1 x 10(-9) mol/L. It also inhibited mutant Flt3 or Kit tyrosine phosphorylation at approximately 1 x 10(-6) mol/L. Mo7e cells expressing the activating mutation (codon 816) of c-Kit were most sensitive to growth inhibition with a GI(50) of 5 x 10(-9) mol/L. Primary AML blast cells exhibited a growth inhibition of \u3c1 x\u3e10(-6) mol/L. Cell lines that showed growth inhibition at approximately 1 x 10(-6) mol/L showed a G(1) cell cycle arrest and correlated with accumulation of p21 and p27 protein. The addition of rapamycin or cytotoxic agents enhanced growth inhibition. Dasatinib also caused the apoptosis of Mo7e cells expressing oncogenic Kit. CONCLUSIONS: Although all of the precise targets for dasatinib are not known, this multikinase inhibitor causes either growth arrest or apoptosis in molecularly heterogeneous AML. The addition of cytotoxic or targeted agents can enhance its effects
    • …
    corecore