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1.
Proc Natl Acad Sci U S A ; 117(39): 24154-24164, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32929006

RESUMO

Science is undergoing rapid change with the movement to improve science focused largely on reproducibility/replicability and open science practices. This moment of change-in which science turns inward to examine its methods and practices-provides an opportunity to address its historic lack of diversity and noninclusive culture. Through network modeling and semantic analysis, we provide an initial exploration of the structure, cultural frames, and women's participation in the open science and reproducibility literatures (n = 2,926 articles and conference proceedings). Network analyses suggest that the open science and reproducibility literatures are emerging relatively independently of each other, sharing few common papers or authors. We next examine whether the literatures differentially incorporate collaborative, prosocial ideals that are known to engage members of underrepresented groups more than independent, winner-takes-all approaches. We find that open science has a more connected, collaborative structure than does reproducibility. Semantic analyses of paper abstracts reveal that these literatures have adopted different cultural frames: open science includes more explicitly communal and prosocial language than does reproducibility. Finally, consistent with literature suggesting the diversity benefits of communal and prosocial purposes, we find that women publish more frequently in high-status author positions (first or last) within open science (vs. reproducibility). Furthermore, this finding is further patterned by team size and time. Women are more represented in larger teams within reproducibility, and women's participation is increasing in open science over time and decreasing in reproducibility. We conclude with actionable suggestions for cultivating a more prosocial and diverse culture of science.


Assuntos
Reprodutibilidade dos Testes , Ciência/tendências , Mulheres , Autoria , Humanos , Disseminação de Informação , Publicação de Acesso Aberto
2.
Alzheimers Dement ; 18(12): 2493-2508, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35142026

RESUMO

INTRODUCTION: Identification of novel therapeutics and risk assessment in early stages of Alzheimer's disease (AD) is a crucial aspect of addressing this complex disease. We characterized gene-expression patterns at the mild cognitive impairment (MCI) stage to identify critical mRNA measures and gene clusters associated with AD pathogenesis. METHODS: We used a transcriptomics approach, integrating magnetic resonance imaging (MRI) and peripheral blood-based gene expression data using persistent homology (PH) followed by kernel-based clustering. RESULTS: We identified three clusters of genes significantly associated with diagnosis of amnestic MCI. The biological processes associated with each cluster were mitochondrial function, NF-kB signaling, and apoptosis. Cluster-level associations with cortical thickness displayed canonical AD-like patterns. Driver genes from clusters were also validated in an external dataset for prediction of amyloidosis and clinical diagnosis. DISCUSSION: We found a disease-relevant transcriptomic signature sensitive to prodromal AD and identified a subset of potential therapeutic targets associated with AD pathogenesis.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Encéfalo/patologia , Endofenótipos , Transcriptoma , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/genética , Neuroimagem/métodos , Imageamento por Ressonância Magnética/métodos , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/genética
3.
PLoS Comput Biol ; 15(3): e1006833, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30849087

RESUMO

Communication of signals among nodes in a complex network poses fundamental problems of efficiency and cost. Routing of messages along shortest paths requires global information about the topology, while spreading by diffusion, which operates according to local topological features, is informationally "cheap" but inefficient. We introduce a stochastic model for network communication that combines local and global information about the network topology to generate biased random walks on the network. The model generates a continuous spectrum of dynamics that converge onto shortest-path and random-walk (diffusion) communication processes at the limiting extremes. We implement the model on two cohorts of human connectome networks and investigate the effects of varying the global information bias on the network's communication cost. We identify routing strategies that approach a (highly efficient) shortest-path communication process with a relatively small global information bias on the system's dynamics. Moreover, we show that the cost of routing messages from and to hub nodes varies as a function of the global information bias driving the system's dynamics. Finally, we implement the model to identify individual subject differences from a communication dynamics point of view. The present framework departs from the classical shortest paths vs. diffusion dichotomy, unifying both models under a single family of dynamical processes that differ by the extent to which global information about the network topology influences the routing patterns of neural signals traversing the network.


Assuntos
Mapeamento Encefálico/métodos , Conectoma , Estudos de Coortes , Comunicação , Humanos , Modelos Neurológicos , Processos Estocásticos
4.
J Stat Mech ; 2014(5)2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-26167197

RESUMO

The proliferation of models for networks raises challenging problems of model selection: the data are sparse and globally dependent, and models are typically high-dimensional and have large numbers of latent variables. Together, these issues mean that the usual model-selection criteria do not work properly for networks. We illustrate these challenges, and show one way to resolve them, by considering the key network-analysis problem of dividing a graph into communities or blocks of nodes with homogeneous patterns of links to the rest of the network. The standard tool for undertaking this is the stochastic block model, under which the probability of a link between two nodes is a function solely of the blocks to which they belong. This imposes a homogeneous degree distribution within each block; this can be unrealistic, so degree-corrected block models add a parameter for each node, modulating its overall degree. The choice between ordinary and degree-corrected block models matters because they make very different inferences about communities. We present the first principled and tractable approach to model selection between standard and degree-corrected block models, based on new large-graph asymptotics for the distribution of log-likelihood ratios under the stochastic block model, finding substantial departures from classical results for sparse graphs. We also develop linear-time approximations for log-likelihoods under both the stochastic block model and the degree-corrected model, using belief propagation. Applications to simulated and real networks show excellent agreement with our approximations. Our results thus both solve the practical problem of deciding on degree correction and point to a general approach to model selection in network analysis.

5.
PeerJ Comput Sci ; 10: e2046, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38855247

RESUMO

The COVID-19 pandemic has far-reaching impacts on the global economy and public health. To prevent the recurrence of pandemic outbreaks, the development of short-term prediction models is of paramount importance. We propose an ARIMA-LSTM (autoregressive integrated moving average and long short-term memory) model for predicting future cases and utilize multi-source data to enhance prediction performance. Firstly, we employ the ARIMA-LSTM model to forecast the developmental trends of multi-source data separately. Subsequently, we introduce a Bayes-Attention mechanism to integrate the prediction outcomes from auxiliary data sources into the case data. Finally, experiments are conducted based on real datasets. The results demonstrate a close correlation between predicted and actual case numbers, with superior prediction performance of this model compared to baseline and other state-of-the-art methods.

6.
Front Immunol ; 15: 1301329, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38322266

RESUMO

Acute retinal necrosis (ARN) is an inflammatory disease that is primarily caused by herpesvirus infection, most commonly varicella-zoster virus (VZV), followed by herpes simplex virus (HSV) and occasionally cytomegalovirus (CMV). Sintilimab is an immune checkpoint inhibitor (ICI) that can enhance the body's anti-tumor immune response. However, treatment with ICIs may lead to reactivation of the VZV. Here, we present a case of ARN caused by VZV infection in a patient receiving sintilimab for cervical cancer. A 64-year-old female patient developed vision loss and floaters with left eye redness for one week after 22 cycles of sintilimab for cervical cancer. Based on clinical manifestations, ophthalmological examination, and vitreous humor biopsy, the patient was diagnosed with acute retinal necrosis syndrome secondary to VZV. After receiving systemic antiviral and anti-inflammatory therapy, retinal necrosis lesions and visual function improved. In conclusion, clinicians should be aware of the risk of ARN when using sintilimab and should actively monitor patients for prompt diagnosis and optimal management of this rare adverse drug reaction.


Assuntos
Anticorpos Monoclonais Humanizados , Herpes Simples , Síndrome de Necrose Retiniana Aguda , Neoplasias do Colo do Útero , Feminino , Humanos , Pessoa de Meia-Idade , Síndrome de Necrose Retiniana Aguda/diagnóstico , Síndrome de Necrose Retiniana Aguda/tratamento farmacológico , Herpesvirus Humano 3
7.
Artigo em Inglês | MEDLINE | ID: mdl-38900613

RESUMO

Attribute graph anomaly detection aims to identify nodes that significantly deviate from the majority of normal nodes, and has received increasing attention due to the ubiquity and complexity of graph-structured data in various real-world scenarios. However, current mainstream anomaly detection methods are primarily designed for centralized settings, which may pose privacy leakage risks in certain sensitive situations. Although federated graph learning offers a promising solution by enabling collaborative model training in distributed systems while preserving data privacy, a practical challenge arises as each client typically possesses a limited amount of graph data. Consequently, naively applying federated graph learning directly to anomaly detection tasks in distributed environments may lead to suboptimal performance results. We propose a federated graph anomaly detection framework via contrastive self-supervised learning (CSSL) federated CSSL anomaly detection framework (FedCAD) to address these challenges. FedCAD updates anomaly node information between clients via federated learning (FL) interactions. First, FedCAD uses pseudo-label discovery to determine the anomaly node of the client preliminarily. Second, FedCAD employs a local anomaly neighbor embedding aggregation strategy. This strategy enables the current client to aggregate the neighbor embeddings of anomaly nodes from other clients, thereby amplifying the distinction between anomaly nodes and their neighbor nodes. Doing so effectively sharpens the contrast between positive and negative instance pairs within contrastive learning, thus enhancing the efficacy and precision of anomaly detection through such a learning paradigm. Finally, the efficiency of FedCAD is demonstrated by experimental results on four real graph datasets.

8.
IEEE Trans Vis Comput Graph ; 29(1): 809-819, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36166552

RESUMO

Data privacy is an essential issue in publishing data visualizations. However, it is challenging to represent multiple data patterns in privacy-preserving visualizations. The prior approaches target specific chart types or perform an anonymization model uniformly without considering the importance of data patterns in visualizations. In this paper, we propose a visual analytics approach that facilitates data custodians to generate multiple private charts while maintaining user-preferred patterns. To this end, we introduce pattern constraints to model users' preferences over data patterns in the dataset and incorporate them into the proposed Bayesian network-based Differential Privacy (DP) model PriVis. A prototype system, DPVisCreator, is developed to assist data custodians in implementing our approach. The effectiveness of our approach is demonstrated with quantitative evaluation of pattern utility under the different levels of privacy protection, case studies, and semi-structured expert interviews.

9.
Eur J Ophthalmol ; 32(1): NP230-NP234, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32811185

RESUMO

PURPOSE: Vogt-Koyanagi-Harada (VKH) is an autoimmune disease with bilateral granulomatous uveitis and various systemic manifestations. Bilateral acute angle closure glaucoma (AACG) can be a rare initial manifestation of VKH that may be misdiagnosed as primary angle closure glaucoma (PACG). CASE REPORT: A 62-year-old woman with bilateral painless loss of vision referred to Qingdao Municipal Hospital. She had been diagnosed as PACG before admission and prescribed with anti-glaucoma treatment which did not improve her symptom. She had severe bilateral uveitis, optic disk swelling, and serous retinal detachment in both eyes. Intraocular pressure (IOP) was 20 mmHg in the right eye and 23 mmHg in the left eye, and her best corrected visual acuities (BCVAs) were 0.02 in both eyes. She was treated with oral corticosteroid therapy on a tapering schedule. One month after the therapy, the IOP remained well-controlled with deepened anterior chamber. Her visual acuity and symptom were improved. CONCLUSIONS: We experienced a case of VKH disease with an unusual presentation of bilateral secondary AACG. It is important for ophthalmologists to know about this rare cause of painless loss of vision so that it could be treated properly.


Assuntos
Glaucoma de Ângulo Fechado , Síndrome Uveomeningoencefálica , Feminino , Glaucoma de Ângulo Fechado/diagnóstico , Glaucoma de Ângulo Fechado/tratamento farmacológico , Glaucoma de Ângulo Fechado/etiologia , Humanos , Pressão Intraocular , Pessoa de Meia-Idade , Tonometria Ocular , Síndrome Uveomeningoencefálica/diagnóstico , Síndrome Uveomeningoencefálica/tratamento farmacológico , Acuidade Visual
10.
Polymers (Basel) ; 14(6)2022 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35335543

RESUMO

Active packaging films were prepared by adding red cabbage anthocyanin extract (RCAE) into acetylated distarch phosphate (ADSP). This paper investigated the influence of the interaction relationship between RCAE and the film matrix on the structure, barrier, antioxidant and release properties of active films. Sixteen principal compounds in RCAE were identified as anthocyanins based on mass spectroscopic analysis. Micromorphological observations indicated that the RCAE distribution uniformity in the films decreased as the RCAE content increased. When the concentration of RCAE was not higher than 20%, the moisture absorption and oxygen permeability of films decreased. The stability of RCAE in the films was enhanced by the electrostatic interaction between RCAE and ADSP with the formation of hydrogen bonds, which facilitated the sustainability of the antioxidant properties of films. The release kinetics of RCAE proved that the release rate of RCAE in active films was the fastest in distilled water, and Fickian's law was appropriate for portraying the release behavior. Moreover, the cytocompatibilty assay showed that the test films were biocompatible with a viability of >95% on HepG2 cells. Thus, this study has established the suitability of the films for applications in active and food packaging.

11.
Int J Biol Macromol ; 195: 264-273, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34920054

RESUMO

This study aimed to develop a composite bilayer film based on corn starch (CS)/polylactic acid (PLA). The film had a hydrophobic outer layer and an absorbent inner layer. A natural bioactive substance was incorporated into the inner layer, namely, eucalyptus essential oil microcapsules (EOM). This allowed most of the bioactive substance to be released inside the storage environment. The effects of different amounts of EOM on the physical, mechanical, antioxidant, and antimicrobial properties of the films were investigated. Based on the results of scanning electron microscopy (SEM), the addition of 10-15 mL/100 mL of EOM could be uniformly distributed in the film. The addition of less than 15 mL/100 mL of EOM to the film improved its tensile strength, barrier properties, and elongation at break. The addition of too much EOM led to cracks in the film. The addition of EOM also greatly improved the antioxidant and antibacterial properties of the bilayer film. The best performance was obtained when the added amount was 15 mL/100 mL. Films with the best overall properties were used for preserving Agaricus bisporus. In preservation experiments, this film inhibited the respiration rate of A. bisporus, slowed down the consumption of organic matter, and maintained its moisture content. Compared with other cling films, the shelf life of A. bisporus was greatly extended.


Assuntos
Óleo de Eucalipto/química , Poliésteres/química , Amido/química , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Eucalyptus , Óleo de Eucalipto/farmacologia , Embalagem de Alimentos/métodos , Óleos Voláteis/química , Folhas de Planta/efeitos dos fármacos , Poliésteres/farmacologia , Amido/farmacologia , Resistência à Tração , Zea mays/efeitos dos fármacos
12.
Mol Vis ; 17: 3384-91, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22219634

RESUMO

PURPOSE: The purpose of this study was to investigate the high potential of glucose in inhibiting the innate immune in cultured human cornea epithelial cells (HCEC) and try to determine whether the role of high glucose on the HCEC relate to toll-like receptor (TLR)2 and TLR4. METHODS: Cells were cultured for 3 days in 5 mmol/l (normal glucose). Then high glucose (25 mmol/l) was added along with normal glucose with daily changes in media for 24 h. The cells were also treated with mannitol as an osmotic control. The cellular abundance of the mRNAs for TLR2 and TLR4 was determined by real-time polymerase chain reaction analysis. The proteins of TLR2 and TLR4 were also compared by immunofluorescent staining and western blot. The release of interleukin 6 (IL-6) and IL-8 from cultured HCEC was measured using enzyme-linked immunosorbent assays (ELISA) in the presence and absence of specific blocking antibodies to TLR2 and TLR4. RESULTS: Incubation of HCEC with high glucose showed that the mRNA expression of TLR2 and TLR4 was markedly inhibited. Immunofluorescent staining and western blot analysis confirmed that the protein expression of TLR2 and TLR4 was downregulated in response to high glucose. The result of ELISA also showed that the release of IL-6 and IL-8 can be inhibited by high glucose, but these inhibitions were partly counteracted after pretreatment with anti-TLR2 and/or anti-TLR4 monoclonal antibody. The results also showed that the osmotic control did not affect the expression of TLR2, TLR4, and IL-6, 8. CONCLUSIONS: High glucose may decrease the innate immune through TLRs in cornea epithelium.


Assuntos
Córnea/imunologia , Células Epiteliais/imunologia , Glucose/fisiologia , Imunidade Inata , Receptor 2 Toll-Like/antagonistas & inibidores , Receptor 4 Toll-Like/antagonistas & inibidores , Anticorpos Neutralizantes/farmacologia , Células Cultivadas , Córnea/citologia , Córnea/efeitos dos fármacos , Regulação para Baixo , Ensaio de Imunoadsorção Enzimática , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Expressão Gênica , Glucose/farmacologia , Humanos , Interleucina-6/biossíntese , Interleucina-8/biossíntese , Manitol/farmacologia , RNA Mensageiro/biossíntese , Reação em Cadeia da Polimerase em Tempo Real , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/imunologia , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia
13.
PLoS One ; 15(9): e0238360, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32886681

RESUMO

This paper analyzes the impact of air transport connectivity and accessibility on scientific collaboration. Numerous studies demonstrated that the likelihood of collaboration declines with increase in distance between potential collaborators. These works commonly use simple measures of physical distance rather than actual flight capacity and frequency. Our study addresses this limitation by focusing on the relationship between flight availability and the number of scientific co-publications. Furthermore, we distinguish two components of flight availability: (1) direct and indirect air connections between airports; and (2) distance to the nearest airport from cities and towns where authors of scientific articles have their professional affiliations. Based on Zero-inflated Negative Binomial Regression, we provide evidence that greater flight availability is associated with more frequent scientific collaboration. More flight connections (connectivity) and proximity of airport (accessibility) increase the expected number of coauthored scientific papers. Moreover, direct flights and flights with one transfer are more valuable for intensifying scientific cooperation than travels involving more connecting flights. Further, analysis of four organizational sub-datasets-Arizona State University, Indiana University Bloomington, Indiana University-Purdue University Indianapolis, and University of Michigan-shows that the relationship between airline transport availability and scientific collaboration is not uniform, but is associated with the research profile of an institution and the characteristics of the airport that serves this institution.


Assuntos
Viagem Aérea/estatística & dados numéricos , Pesquisa Biomédica/estatística & dados numéricos , Pesquisa Biomédica/tendências , Comportamento Cooperativo , Publicações Periódicas como Assunto/estatística & dados numéricos , Publicações/estatística & dados numéricos , Meios de Transporte/estatística & dados numéricos , Pesquisa Biomédica/organização & administração , Humanos , Meios de Transporte/métodos , Universidades
14.
Front Big Data ; 3: 556282, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33693415

RESUMO

Big bibliographic datasets hold promise for revolutionizing the scientific enterprise when combined with state-of-the-science computational capabilities. Yet, hosting proprietary and open big bibliographic datasets poses significant difficulties for libraries, both large and small. Libraries face significant barriers to hosting such assets, including cost and expertise, which has limited their ability to provide stewardship for big datasets, and thus has hampered researchers' access to them. What is needed is a solution to address the libraries' and researchers' joint needs. This article outlines the theoretical framework that underpins the Collaborative Archive and Data Research Environment project. We recommend a shared cloud-based infrastructure to address this need built on five pillars: 1) Community-a community of libraries and industry partners who support and maintain the platform and a community of researchers who use it; 2) Access-the sharing platform should be accessible and affordable to both proprietary data customers and the general public; 3) Data-Centric-the platform is optimized for efficient and high-quality bibliographic data services, satisfying diverse data needs; 4) Reproducibility-the platform should be designed to foster and encourage reproducible research; 5) Empowerment-the platform should empower researchers to perform big data analytics on the hosted datasets. In this article, we describe the many facets of the problem faced by American academic libraries and researchers wanting to work with big datasets. We propose a practical solution based on the five pillars: The Collaborative Archive and Data Research Environment. Finally, we address potential barriers to implementing this solution and strategies for overcoming them.

15.
Zhonghua Yan Ke Za Zhi ; 44(4): 310-4, 2008 Apr.
Artigo em Zh | MEDLINE | ID: mdl-18844016

RESUMO

OBJECTIVE: To investigate the killing efficiency of PWZL plasmid-mediated herpes simplex virus-thymidine kinase (TK) and E. coli cytosine deaminase (CD) on human lens epithelium cells followed by the treatment of prodrugs. METHODS: PWZL plasmid was used as a vehicle, to transduce double suicide genes into the human lens epithelium in vitro, then the cells were treated with fluorocytosine (5-FC) and/or ganciclovir (GCV) at different concentrations. The cell growth of the lens epithelium cells was observed by light microscope. MTT analysis was used to estimate the cell survival rate and the bystander effect was analyzed simultaneously. The significance of difference between each group was treated by statistical tests. RESULTS: The CD and TK gene could be joined into PWZL plasmid successfully, and did not have any special effect on normal cells. There was no significant difference in cell viability between CD-TK transfected cells and control cells. Cell viability in cells treated with prodrugs was decreased in a time-dependent manner. At the end of the experiment, cell viability was lowest in GCV 10 mg/L +5-FC 60 mg/L group, GCV 10 mg/L + 5-FC 100 mg/L group and GCV 100 mg/L + 5-FC 100 mg/L group. There were no significant differences between these three groups (X2 = 1.25 , P > 0.01). Analysis of bystander effect indicated that the cell viability in GCV 100 mg/L + 5-FC 100 mg/L group and GCV 10 mg/L +5-FC 60 mg/L group was significantly lower than that in the controls (t = 10.26, 13.16; P < 0.01). CONCLUSIONS: PWZL plasmid can transfect the CD and TK genes into lens epithelium cells successfully and efficiently. CD and TK genes can be expressed steadily. Transfection of double suicide gene reduces the dosage of prodrugs required for killing cells. The combination of 5-FC with GCV shows the greatest killing effect and also has the bystander effect.


Assuntos
Citosina Desaminase/genética , Células Epiteliais/efeitos dos fármacos , Genes Transgênicos Suicidas , Cristalino/citologia , Timidina Quinase/genética , Sobrevivência Celular , Células Cultivadas , Células Epiteliais/citologia , Escherichia coli/enzimologia , Escherichia coli/genética , Flucitosina/farmacologia , Ganciclovir/farmacologia , Terapia Genética , Vetores Genéticos , Humanos , Plasmídeos , Transfecção
16.
Sci Rep ; 8(1): 12997, 2018 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-30158553

RESUMO

The human brain can be described as a complex network of anatomical connections between distinct areas, referred to as the human connectome. Fundamental characteristics of connectome organization can be revealed using the tools of network science and graph theory. Of particular interest is the network's community structure, commonly identified by modularity maximization, where communities are conceptualized as densely intra-connected and sparsely inter-connected. Here we adopt a generative modeling approach called weighted stochastic block models (WSBM) that can describe a wider range of community structure topologies by explicitly considering patterned interactions between communities. We apply this method to the study of changes in the human connectome that occur across the life span (between 6-85 years old). We find that WSBM communities exhibit greater hemispheric symmetry and are spatially less compact than those derived from modularity maximization. We identify several network blocks that exhibit significant linear and non-linear changes across age, with the most significant changes involving subregions of prefrontal cortex. Overall, we show that the WSBM generative modeling approach can be an effective tool for describing types of community structure in brain networks that go beyond modularity.


Assuntos
Encéfalo/anatomia & histologia , Encéfalo/fisiologia , Conectoma , Modelos Neurológicos , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
17.
PLoS One ; 11(2): e0147617, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26886112

RESUMO

Individual's decisions, from what product to buy to whether to engage in risky behavior, often depend on the choices, behaviors, or states of other people. People, however, rarely have global knowledge of the states of others, but must estimate them from the local observations of their social contacts. Network structure can significantly distort individual's local observations. Under some conditions, a state that is globally rare in a network may be dramatically over-represented in the local neighborhoods of many individuals. This effect, which we call the "majority illusion," leads individuals to systematically overestimate the prevalence of that state, which may accelerate the spread of social contagions. We develop a statistical model that quantifies this effect and validate it with measurements in synthetic and real-world networks. We show that the illusion is exacerbated in networks with a heterogeneous degree distribution and disassortative structure.


Assuntos
Ilusões , Rede Social , Humanos , Distribuição Normal
18.
PLoS One ; 10(6): e0126052, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26030210

RESUMO

PURPOSE: To assess the accuracy of the Plusoptix A09 photoscreener in detecting amblyopia risk factors in children and determine referral criteria when using Plusoptix A09 for a large-scale vision screening. METHODS: Pediatric patients attending our eye clinic underwent a comprehensive ophthalmic examination that included photorefraction, orthoptic examination, anterior segment assessment, fundus examination and cycloplegic retinoscopy. The measurements were collected for statistical analyses. RESULTS: One hundred and seventy-eight children (mean age ± SD: 6.2±2.4 years, range: 2.2 to 14.1 years) were included in the study. The mean spherical equivalent (SE) obtained using Plusoptix A09 (PSE) was 0.57 D lower than that obtained from cycloplegic retinoscopy (CRSE) (P = 0.00). However, there was no statistically significant difference of Jackson cross cylinder J0 and J45 between Plusoptix A09 (PJ) and cycloplegic retinoscopy (CRJ) (P = 0.14, P = 0.26). The relationship of SE obtained from Plusoptix A09 and SE obtained from cycloplegic retinoscopy was presented as the equation: CRSE = 0.358 + 0.776 PSE + 0.064 PSE2 + 0.011 PSE3. Based on the Receiver Operating Characteristic (ROC) curve, the Plusoptix A09 had an overall sensitivity of 94.9% and specificity of 67.5% for detecting refractive amblyopia risk factors. The sensitivity and specificity of the Plusoptix A09 for detection of strabismus were 40.7% and 98.3%, respectively; detection of amblyopia and/or strabismus was 84.7% and 63.2%, respectively. CONCLUSIONS: The Plusoptix A09 photoscreener underestimated hyperopia and overestimated myopia according to SE when compared with cycloplegic retinoscopy. The accuracy of the Plusoptix A09 in detecting amblyopia risk factors in children could be improved by the regression equation and optimized criteria for refractive amblyopia risk factors developed in the present study. Moreover, the Plusoptix A09 photoscreener is not suitable for a large-scale strabismus screening when it is applied solely.


Assuntos
Ambliopia/diagnóstico , Seleção Visual/métodos , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Fatores de Risco , Sensibilidade e Especificidade
19.
Zhonghua Yan Ke Za Zhi ; 39(10): 621-5, 2003 Oct.
Artigo em Zh | MEDLINE | ID: mdl-14766078

RESUMO

OBJECTIVE: To investigate the antiproliferative effect of different concentration of all-trans retinoic acid (atRA) in a drug delivery system (DDS) in an experimental proliferative vitreoretinopathy (PVR) model. METHODS: The PVR animal model was induced by central vitrectomy and homologous fibroblasts injected at the same time in pigmented rabbits. Fifty rabbits underwent the surgery. These rabbits were divided into 5 groups of 10 rabbits at random. Group A was the control group. In group B, C, and E, one DDS device was implanted into the vitreous cavity after the vitrectomy, each DDS contained atRA 420 microg, 650 microg and no drug, respectively. In group D, two DDS devices were placed into the vitreous cavity, the total atRA content was 1,070 microg (420 microg + 650 microg). Each group was observed for 8 weeks. The development and the severity of PVR were observed and recorded. The vitreous cavity fluid was aspirated each week for measurement of the concentration of the atRA, in order to estimate the relationship between PVR and concentration of atRA. After 8 weeks, the retinal toxicity was evaluated by histopathology. Statistical analyses were performed at the end of the experiment. RESULTS: Eight weeks after the operation, the incidence of PVR was lower in group C and group D, and there was a significantly statistical difference between these two groups and other groups. No intraocular toxicity was found by the histopathology examination. CONCLUSIONS: atRA DDS is a safe and convenient mode for intraocular administration. DDS containing 650 microg and 1,070 microg atRA can inhibit the cell proliferation in the vitreous cavity effectively after surgery. atRA at a lower concentration cannot eliminate the cell proliferation but may delay the occurrence of PVR.


Assuntos
Implantes de Medicamento , Tretinoína/administração & dosagem , Vitreorretinopatia Proliferativa/tratamento farmacológico , Corpo Vítreo/efeitos dos fármacos , Animais , Divisão Celular/efeitos dos fármacos , Preparações de Ação Retardada , Feminino , Masculino , Coelhos , Tretinoína/metabolismo
20.
Ocul Immunol Inflamm ; 19(4): 275-81, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21770806

RESUMO

PURPOSE: To evaluate the effect of glucocorticoids on the innate immunity of corneal epithelial cells. METHODS: Human corneal epithelial cell lines (HCEC) were co-cultured with LPS and hydrocortisone to determine whether hydrocortisone modulates the expression and function of TLR2, 4. The release of IL-6, 8 from cultured HCEC was measured in the presence and absence of specific blocking antibodies to TLR2, 4. The proteins of TLR2, 4 were also compared by Western blot. RESULTS: Incubation of HCEC with LPS upregulated the expression of TLR2, 4 and increased the release of IL-6, 8. This upregulation was enhanced by low-concentration hydrocortisone, but inhibited by high-concentration hydrocortisone. The concentration of IL-6, 8 was also enhanced by low-concentration hydrocortisone and inhibited by high-concentration hydrocortisone. CONCLUSIONS: Low-concentration hydrocortisone enhances the expression and function of TLRs in HCEC and provides evidence for a novel function of glucocorticoids in innate immunity.


Assuntos
Epitélio Corneano/imunologia , Hidrocortisona/administração & dosagem , Imunidade Inata/efeitos dos fármacos , Linhagem Celular Transformada , Relação Dose-Resposta a Droga , Células Epiteliais/imunologia , Epitélio Corneano/citologia , Epitélio Corneano/metabolismo , Humanos , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Lipopolissacarídeos/farmacologia , Concentração Osmolar , RNA Mensageiro/metabolismo , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Regulação para Cima/efeitos dos fármacos
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