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1.
Environ Sci Pollut Res Int ; 31(12): 18200-18208, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37002519

RESUMO

Solar energy is one of the most feasible options to produce energy in countries where unexploited desert areas or solar radiation are abundant. An energy tower is an effective system for electrical power generation that can perform more efficiently along with solar radiation. As the primary aim of the present study, effects of different environmental parameters on total efficacy of energy tower were investigated. In this study, the efficiency of the energy tower system is investigated experimentally by an indoor fully adjustable apparatus. In this regard, a comprehensive set of influencing parameters like air velocity, humidity, and temperature and the effects of tower height on the performance of the energy tower are individually assessed. It is demonstrated that there is a direct relationship between an increase in humidity percentage of the surrounding and performance of energy tower, meaning that a 274% increase in humidification rate led to 43% elevation in airflow velocity. The kinetic energy increases in the direction of airflow from top to bottom, and as the height of the tower lengthens, the kinetic energy enhances and subsequently increases the overall efficiency of the tower. An elevation about 2.7% in airflow velocity was seen due to an increase from 180 to 250 cm in chimney height. Although the energy tower performs efficiently in the nighttime, airflow velocity increases averagely about 8% during the daytime and at the peak of the solar radiation, the airflow velocity enhances by 58% compared to nighttime.


Assuntos
Energia Solar , Umidade , Temperatura
2.
PLoS One ; 18(6): e0286991, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37327243

RESUMO

Some states in the U.S. have traditionally received less federal research funding than other states. The National Science Foundation (NSF) created a program in 1979, called the Experimental Program to Stimulate Competitive Research (EPSCoR) to enhance the research competitiveness in such states. While the geographic disparity in federal research funding is well known, the overall impact of federal funding on the research performance of EPSCoR and non-EPSCoR has not been previously studied. In the current study, we compared the combined research productivity of Ph.D. granting institutions in EPSCoR versus the non-EPSCoR states to better understand the scientific impact of federal investments in sponsored research across all states. The research outputs we measured included journal articles, books, conference papers, patents, and citation count in academic literature. Unsurprisingly, results indicated that the non-EPSCoR states received significantly more federal research funding than their EPSCoR counterparts, which correlated with a higher number of faculty members in the non-EPSCoR versus EPSCoR states. Also, in the overall research productivity expressed on a per capita, the non-EPSCoR states fared better than EPSCoR states. However, when the research output was measured based on per $1M investment of federal research funding, EPSCoR states performed significantly better than the non-EPSCoR states in many research productivity indicators, with the notable exception of patents. Together, this study found preliminary evidence that EPSCoR states achieved a high degree of research productivity despite receiving significantly fewer federal research dollars. The limitations and next steps of this study are also discussed.


Assuntos
Eficiência , Organização do Financiamento , Humanos , Estados Unidos , Estudos Longitudinais , Docentes , National Institutes of Health (U.S.)
3.
JAMA Netw Open ; 6(4): e238897, 2023 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-37074713

RESUMO

Importance: Social media is simultaneously home to communities of users who promote eating disorders as a lifestyle and users who advocate for recovery. As studies have confirmed an association between exposure to pro-eating disorder content and engaging in disordered eating behaviors, an examination of the accuracy of and interactions with information shared in these complex and contradictory communities can provide insights into content available to users at risk. Objective: To determine the associations among themes, accuracy of information, and user engagement of eating disorder content on a short video-sharing social media platform. Design, Setting, and Participants: This qualitative study included a thematic analysis of a sample of 200 TikTok videos, as well as user engagement metrics and content creator characteristics, between February and June 2022. Data were analyzed from March to June 2022. Main Outcomes and Measures: Content themes, accuracy of information, user engagement, and the associations among these factors were identified in a sample of eating disorder videos on a social media platform. Data were analyzed with Pearson χ2, analysis of variance, linear regression, and random permutation tests. Results: Among the 200 videos assessed, 124 (62.0%) covered prorecovery content, 59 (29.5%) included pro-eating disorder content, and 17 (8.5%) contained anti-eating disorder content. Thematic analysis revealed 4 high-level themes: (1) encouraging the development or sustainment of eating disorders, (2) sharing physical or emotional experiences with eating disorders, (3) sharing narratives of recovery, and (4) social support. While the results of Pearson χ2 test indicated that videos in the prorecovery domain contained more accurate content than videos categorized in the pro-eating disorder and anti-eating disorder domains (χ24 = 157.92; P < .001), the results of analysis of variance demonstrated that there was no significant difference in user engagement between informative and misleading content (likes: F = 0.110; P = .95; comments: F = 2.031; P = .13; views: F = 0.534; P = .59; shares: F = 0.691; P = .50). Results of the 10 000 random permutation tests, in which all P values were between .40 and .60 regardless of the distances, suggested that there was no significant difference in user engagement among the 3 domains. Conclusions and Relevance: This mixed-methods qualitative analysis of misleading eating disorder information on social media found that pro-eating disorder and prorecovery communities were prevalent. However, social media users in the prorecovery community created more informative than misleading content. Furthermore, the study found no significant difference between users' engagement with accurate vs misleading videos, which may suggest that false information alone does not influence the virality of videos.


Assuntos
Transtornos da Alimentação e da Ingestão de Alimentos , Mídias Sociais , Humanos , Emoções , Apoio Social
4.
PLoS One ; 15(10): e0239282, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33095778

RESUMO

OBJECTIVES: To determine if the URO-MCP-1 mouse model for bladder IC/BPS is associated with in vivo bladder hyper-permeability, as measured by contrast-enhanced MRI (CE-MRI), and assess whether molecular-targeted MRI (mt-MRI) can visualize in vivo claudin-2 expression as a result of bladder hyper-permeability. Interstitial cystitis/bladder pain syndrome (IC/BPS) is a chronic, painful condition of the bladder that affects primarily women. It is known that permeability plays a substantial role in IC/BPS. Claudins are tight junction membrane proteins that are expressed in epithelia and endothelia and form paracellular barriers and pores that determine tight junction permeability. Claudin-2 is a molecular marker that is associated with increased hyperpermeability in the urothelium. MATERIALS AND METHODS: CE-MRI was used to measure bladder hyper-permeability in the URO-MCP-1 mice. A claudin-2-specific mt-MRI probe was used to assess in vivo levels of claudin-2. The mt-MRI probe consists of an antibody against claudin-2 conjugated to albumin that had Gd-DTPA (gadolinium diethylenetriamine pentaacetate) and biotin attached. Verification of the presence of the mt-MRI probe was done by targeting the biotin moiety for the probe with streptavidin-horse radish peroxidase (SA-HRP). Trans-epithelial electrical resistance (TEER) was also used to assess bladder permeability. RESULTS: The URO-MCP-1 mouse model for IC/BPS was found to have a significant increase in bladder permeability, following liposaccharide (LPS) exposure, compared to saline-treated controls. mt-MRI- and histologically-detectable levels of the claudin-2 probe were found to increase with LPS -induced bladder urothelial hyper-permeability in the URO-MCP-1 IC mouse model. Levels of protein expression for claudin-2 were confirmed with immunohistochemistry and immunofluorescence imaging. Claudin-2 was also found to highly co-localize with zonula occlidens-1 (ZO-1), a tight junction protein. CONCLUSION: The combination of CE-MRI and TEER approaches were able to demonstrate hyper-permeability, a known feature associated with some IC/BPS patients, in the LPS-exposed URO-MCP-1 mouse model. This MRI approach could be clinically translated to establish which IC/BPS patients have bladder hyper-permeability and help determine therapeutic options. In addition, the in vivo molecular-targeted imaging approach can provide invaluable information to enhance our understanding associated with bladder urothelium hyper-permeability in IC/BPS patients, and perhaps be used to assist in developing further therapeutic strategies.


Assuntos
Claudina-2/metabolismo , Cistite Intersticial/patologia , Imageamento por Ressonância Magnética/métodos , Sondas Moleculares/química , Bexiga Urinária/fisiopatologia , Animais , Anticorpos/química , Anticorpos/imunologia , Claudina-2/imunologia , Cistite Intersticial/metabolismo , Modelos Animais de Doenças , Gadolínio DTPA/química , Imuno-Histoquímica , Lipopolissacarídeos/toxicidade , Camundongos , Permeabilidade/efeitos dos fármacos , Albumina Sérica/química
5.
Appl Radiat Isot ; 68(1): 84-9, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19748787

RESUMO

Photoneutrons produced during radiation therapy with high energy photons is the main source of unwanted out-of-field received doses of patients. To analyze the neutron dose equivalent (NDE) for wedged beams and its variation with field size, Monte Carlo (MC) modeling of an 18MV photon beam was performed using MCNPX MC code. The results revealed that the NDE is on average 6.5 times higher for wedged beams. For open beams, the NDE decreased with increasing field size especially for field sizes >20x20cm(2). While, for wedged beams, the NDE increased with field size. It was suggested that the increase of NDE for wedged beams should be taken into account in radiation-induced secondary cancer risk estimations and radiation protection calculations.


Assuntos
Nêutrons , Aceleradores de Partículas/instrumentação , Proteção Radiológica/instrumentação , Dosagem Radioterapêutica , Humanos , Método de Monte Carlo , Fótons
6.
Radiat Prot Dosimetry ; 138(2): 123-8, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19789200

RESUMO

The effect of an automatic wedge filter on photon and photoneutron spectra of a medical linac was evaluated using the Monte Carlo method. The head of an Elekta SL75/25 was simulated using the MCNPX Monte Carlo code. The photon and photoneutron spectra for open and wedged beams were calculated at the isocentre with a source to axis distance of 100 cm. For a wedged beam, the neutron fluence was from 3.84 to 7.2 times higher for field sizes from 10 x 10 to 30 x 30 cm(2). The neutron fluence is decreased with field size for open beams and is increased with field size for wedged beams The photon beam spectra became harder and the mean energy was 6 % higher for a wedged beam, which led to a 4 % increase in relative depth dose and a better skin sparing effect. The results here recommend that the higher photoneutron fluence of the wedged beam should be taken into account in patient dosimetry and shielding calculations.


Assuntos
Nêutrons , Aceleradores de Partículas/instrumentação , Fótons , Simulação por Computador , Humanos , Método de Monte Carlo
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