188 research outputs found
Overuse of Fluoride in Public Water Systems: Stimulating Fluorosis Rather Than Preventing Dental Caries
In the early 1940’s, researchers sponsored by the Centers for Disease Control and Prevention (CDC) discovered an inverse correlation between the prevalence of dental caries and the quantity of fluoride consumption and exposure. As a result of this finding, the Environmental Protection Agency under the advisement of the CDC instructed municipalities in the United States to fluoridate their public water systems in order to increase fluoride exposure. More recently though, other researchers have concluded that there is a positive correlation between another dental condition, dental fluorosis, and fluoride consumption and have made recommendations to decrease fluoride consumption due to the aesthetic and physical damage associated with dental fluorosis. The researchers also suggested that the African American population in municipalities with fluoridated water systems expressed significantly higher susceptibility to dental fluorosis due to biological susceptibility and cultural practices. A study was conducted on the concentrations of fluoride in public water systems of municipalities with large African American populations. Because the African American demographic is essentially being overdosed with fluoride, it can be suggested that communities with large African American populations ought to reduce the concentration of fluoride in their water systems or completely eliminate public water fluoridation and give residents the option of accessing fluoride in the form of dental products or fluoride supplements. Until fluoride reduction is achievable, public health officials need to inform and educate African Americans of the risks associated with dental fluorosis and the preventative measures that African Americans, as well as other individuals, can utilize to reduce their fluorosis susceptibility.https://scholarscompass.vcu.edu/uresposters/1028/thumbnail.jp
Among Us
The networked society provides an extremely complex environment where we are free to swim, and to sink. In this thesis, I used different materials and forms to visualize this concept. The final work is a series of human faces floating from the water surface with steady gaze. Affected by the background of my sculpture and oil painting, I explored how to combine the two, and drew a 3D portrait, then completely transformed from two-dimensional to three-dimensional, and produced a set of installations with repeated face elements. With the experience and emotional response to working three-dimensionally, I once again returned to oil painting and completed a final portrait work, closing the loop from illusion to reality to illusion. This thesis is a record of my journey. It details how I shaped different materials and forms, how they blended with each other and shaped my work itself, as well as my exploration of how we should face the complex emotional expression of other people in such an environment, and how we should pursue a final self-balance
Bohr-type inequalities for unimodular bounded analytic functions
In this paper, we establish several new versions of Bohr-type inequalities
for bounded analytic functions in the unit disk by allowing
in place of the
in the power series representations of the functions
involved with the Bohr sum and thereby introducing a single parameter, which
generalize several related results of earlier authors.Comment: 13 pages. The article is with a journa
Design of a Drug Delivery System through the Gastrointestinal Tract
Alzheimer’s Disease (AD) afflicts an estimated 5.3 million individuals and is the sixth leading cause of death in America. The drug delivery method of interest is an orally administered sustained-release delivery system that addresses the needs of the associated patient population. By augmenting drug delivery with a higher effective payload per dose compared to current methods, drug efficacy and bioavailability would improve. This will result in a decrease of the overall cost for medication as a greater percentage of the administered drug will be viable.
This design addresses the release of AD drug from the drug delivery system at the small intestine. The design specifications are uniqueness and novelty, cost, ease of use, compatibility, toxicity, shelf life, and pH sensitivity. This design features the utilization of a pH sensitive hydrogel composed of PEGDA and PMMA-co-MMA that will encapsulate the drug through the GI tract and respond appropriately to stimuli in the small intestine to release its content in an appropriate manner. This prevents the release of drug in acidic environments like the stomach where it will be degraded. From experimental studies, the hydrogel drug delivery system was found to be effective. Drug release kinetics using fluorescent dyes indicated that the release was greatest in the pH environment that simulated that found in the small intestines whereas the release was the lowest in very acidic pH levels simulating the acidity of the stomach.https://scholarscompass.vcu.edu/capstone/1076/thumbnail.jp
Ariadne's Thread:Using Text Prompts to Improve Segmentation of Infected Areas from Chest X-ray images
Segmentation of the infected areas of the lung is essential for quantifying
the severity of lung disease like pulmonary infections. Existing medical image
segmentation methods are almost uni-modal methods based on image. However,
these image-only methods tend to produce inaccurate results unless trained with
large amounts of annotated data. To overcome this challenge, we propose a
language-driven segmentation method that uses text prompt to improve to the
segmentation result. Experiments on the QaTa-COV19 dataset indicate that our
method improves the Dice score by 6.09% at least compared to the uni-modal
methods. Besides, our extended study reveals the flexibility of multi-modal
methods in terms of the information granularity of text and demonstrates that
multi-modal methods have a significant advantage over image-only methods in
terms of the size of training data required.Comment: Provisional Acceptance by MICCAI 202
The acute toxicity of cypermethrin, emamectin benzoate and imidacloprid on red swamp crayfish (<em>Procambarus clarkia</em>)
Pesticide contamination is commonly found as a mixture of different pesticides rather than individual compounds. However, the regulatory risk evaluation is mostly based on the effects of individual pesticides. In the present study, we aimed to investigate the individual and combined toxicities of cypermethrin (CYP) with emamectin benzoate (EMB) and imidacloprid (IMI) to crayfish using acute indices and various sub-lethal endpoints. Semi-static bioassay procedures were followed in the experiment. The 24, 48, and 72 h LC~50~ values (with 95% confidence limits) of CYP for crayfish were calculated as 0.141, 0.137, and 0.135 ug/ml, respectively, which were higher than those of IMI (75.813, 72.345, 70.568 ug/ml) and EMB (34.581, 27.930, 22.298 ug/ml). Pesticide mixtures of CYP and EMB displayed a synergistic response to crayfish; the LC50 was 0.053, 0.050, and 0.048 ug/ml, which was lower than when only CYP was present. Pesticide mixtures of CYP and EMB were found to be highly toxic to crayfish. At the physiological level, both individuals and mixtures of pesticides caused severe injury to the internal organs of crayfish. Taken together, the synergistic effects indicated that it was highly important to include joint toxicity studies when assessing the risk of pesticides
Orexin-A protects against oxygen-glucose deprivation/reoxygenation-induced cell damage by inhibiting endoplasmic reticulum stress-mediated apoptosis via the Gi and PI3K signaling pathways
The neuropeptide orexin-A (OXA) has a neuroprotective effect, acting as an anti-apoptotic factor in response to multiple stimuli. Apoptosis induced by endoplasmic reticulum stress (ERS) underlies oxygen-glucose deprivation and reoxygenation (OGD/R)-induced cell damage, an in vitro model of ischemia/reperfusion injury. However, that OXA inhibits ERS-induced apoptosis in the OGD/R model has not been reported. In the present study, we investigated the neuroprotective effect of OXA (0.1 μM) on OGD/R-induced damage in the human neuroblastoma cell line SH-SY5Y. After OXA treatment following 4 h oxygen-glucose deprivation (OGD) and then 4 h reoxygenation (R), cell morphology, viability, and apoptosis were analyzed by histology, Cell Counting Kit-8 assay, and flow cytometry, respectively. Western blotting was used to measure expression levels of ERS- and apoptosis-related proteins. To determine signaling pathways involved in OXA-mediated neuroprotection, the Gi pathway inhibitor pertussis toxin (PTX; 100 ng/mL) and PI3K inhibitor LY294002 (LY; 10 μM) were added. In addition, in order to prove the specificity of these characteristics, the OXA antagonist Suvorexant (DORA; Ki of 0.55 nM and 0.35 nM for OX1R and OX2R) was used for intervention. Our results showed that OGD/R induced cell damage, manifested as morphological changes and a significant decrease in viability. Furthermore, Western blotting detected an increase in ERS-related proteins GRP78, p-IRE1α, p-JNK, and Cleaved caspase-12, as well as apoptosis-related proteins Cleaved caspase-3 and Bax, and a decrease in the anti-apoptosis factor Bcl-2. OXA intervention alleviated the degree of cellular damage, and protein expression was also reversed. In addition, the protective effect of OXA was reduced by adding PTX and LY. Meanwhile, after the use of DORA, changes in the expression of related proteins were detected, and it was found that the protective effect of OXA was weakened. Collectively, our results indicate that OXA has a neuroprotective effect on OGD/R-induced cell damage by inhibiting ERS-induced apoptosis through the combined action of Gi and PI3K signaling pathways. These findings help to clarify the mechanism underlying the neuroprotective action of OXA, which should aid the development of further candidate drugs, and provide a new therapeutic direction for the treatment of ischemic stroke
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