Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 114
Filtrar
1.
Angew Chem Int Ed Engl ; 63(33): e202407794, 2024 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-38896057

RESUMO

Vat photopolymerization 3D printing has proven very successful for the rapid additive manufacturing (AM) of polymeric parts at high resolution. However, the range of materials that can be printed and their resulting properties remains narrow. Herein, we report the successful AM of a series of poly(carbonate-b-ester-b-carbonate) elastomers, derived from carbon dioxide and bio-derived ϵ-decalactone. By employing a highly active and selective Co(II)Mg(II) polymerization catalyst, an ABA triblock copolymer (Mn=6.3 kg mol-1, ÐM=1.26) was synthesized, formulated into resins which were 3D printed using digital light processing (DLP) and a thiol-ene-based crosslinking system. A series of elastomeric and degradable thermosets were produced, with varying thiol cross-linker length and poly(ethylene glycol) content, to produce complex triply periodic geometries at high resolution. Thermomechanical characterization of the materials reveals printing-induced microphase separation and tunable hydrophilicity. These findings highlight how utilizing DLP can produce sustainable materials from low molar mass polyols quickly and at high resolution. The 3D printing of these functional materials may help to expedite the production of sustainable plastics and elastomers with potential to replace conventional petrochemical-based options.

2.
Sensors (Basel) ; 23(10)2023 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-37430795

RESUMO

Functional objects are large and small physical entities installed in urban environments to offer specific functionalities to visitors, such as shops, escalators, and information kiosks. Instances of the novel notion are focal points of human activities and are significant in pedestrian movement. Pedestrian trajectory modelling in an urban scene is a challenging problem because of the complex patterns resulting from social interactions of the crowds and the diverse relation between pedestrians and functional objects. Many data-driven methods have been proposed to explain the complex movements in urban scenes. However, the methods considering functional objects in their formulation are rare. This study aims to reduce the knowledge gap by demonstrating the importance of pedestrian-object relations in the modelling task. The proposed modelling method, called pedestrian-object relation guided trajectory prediction (PORTP), uses a dual-layer architecture that includes a predictor of pedestrian-object relation and a series of relation-specific specialized pedestrian trajectory prediction models. The experiment findings indicate that the inclusion of pedestrian-object relation results in more accurate predictions. This study provides an empirical foundation for the novel notion and a strong baseline for future work on this topic.

3.
J Chem Educ ; 99(5): 1877-1889, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37552781

RESUMO

Chemistry laboratory experiments are invaluable to students' acquisition of necessary synthetic, analytical, and instrumental skills during their undergraduate studies. However, the COVID-19 pandemic rendered face-to-face (f2f), in-person teaching laboratory experiences impossible from late 2019-2020 and forced educators to rapidly develop new solutions to deliver chemistry laboratory education remotely. Unfortunately, achieving learning and teaching objectives to the same caliber of in-person experiments is very difficult through distance learning. To overcome these hurdles, educators have generated many virtual and remote learning options for not only foundational chemistry courses but also laboratory experiments. Although the pandemic challenged high-level chemistry education, it has also created an opportunity for both students and educators to be more cognizant of virtual learning opportunities and their potential benefits within chemistry curriculum. Irrespective of COVID-19, virtual learning techniques, especially virtual lab experiments, can complement f2f laboratories and offer a cost-efficient, safe, and environmentally sustainable alternative to their in-person counterparts. Implementation of virtual and distance learning techniques-including kitchen chemistry and at-home laboratories, prerecorded videos, live-stream video conferencing, digital lab environment, virtual and augmented reality, and others-can provide a wide-ranging venue to teach chemistry laboratories effectively and encourage diversity and inclusivity in the field. Despite their relevance to real-world applications and potential to expand upon fundamental chemical principles, polymer lab experiments are underrepresented in the virtual platform. Polymer chemistry education can help prepare students for industrial and academic positions. The impacts of polymers in our daily life can also promote students' interests in science and scientific research. Hence, the translation of polymer lab experiments into virtual settings improves the accessibility of polymer chemistry education. Herein, we assess polymer experiments in the emergence of virtual learning environments and provide suggestions for further incorporation of effective polymer teaching and learning techniques into virtual settings.

4.
J Sport Rehabil ; 31(7): 894-903, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35487575

RESUMO

INTRODUCTION: While anterior cruciate ligament (ACL) tears are commonly managed with ACL reconstruction (ACL-R), 35% of ACL-R individuals fail to return to the preinjury elite sport level. Persistent neuromuscular deficits in the hamstrings and quadriceps have been observed. It has been proposed that aquatic therapy can be used to optimize neuromuscular control after ACL-R. OBJECTIVES: (1) To compare muscle activity in ACL-R individuals during aquatic treadmill (ATM) running at different water depths and (2) to compare muscle activity during ATM running between ACL-R and healthy individuals. METHODS: A total of 38 participants, including 18 ACL-R individuals (mean postoperative time [SD] = 25.8 [25.0] mo) and 20 healthy individuals were recruited. Muscle activity of biceps femoris (BF), rectus femoris (RF), tibialis anterior, and medial gastrocnemius during land treadmill and ATM running at mid-shin, mid-thigh, and waist levels were recorded using surface electromyography (sEMG).  The sEMG signals of the selected muscles were normalized and expressed in % Maximal Voluntary Contraction (%MVC). Muscle activity of the ACL-R, ACL-contralateral, and healthy control limbs at different water depths was compared. RESULTS: Among the 3 groups, the ACL-R group demonstrated the most prominent percentage increase of 101.97% (P = .001) at mid-shin level, 139.66% (P = .001) at mid-thigh level, and 141.97% (P < .001) at waist level, respectively, in %MVC when compared to land. In the ACL-R group, muscle activity of BF in the stance phase (BFSt) was significantly higher than the control group on land at all water depths. Muscle activity of RF in the swing phase (RFSw) in the ACL-R group significantly increased in all water depths immersion when compared to land, respectively. CONCLUSION: This study showed an increasing trend in muscle activity of BFSt and RFSw in ACL-R individuals during ATM running at increased water depths. ATM running could be implemented as neuromuscular training in rehabilitation after ACL-R.


Assuntos
Lesões do Ligamento Cruzado Anterior , Reconstrução do Ligamento Cruzado Anterior , Músculos Isquiossurais , Corrida , Lesões do Ligamento Cruzado Anterior/cirurgia , Eletromiografia , Músculos Isquiossurais/fisiologia , Humanos , Músculo Esquelético/fisiologia , Músculo Quadríceps/fisiologia , Corrida/fisiologia , Água
5.
Sex Transm Infect ; 97(3): 215-220, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33087479

RESUMO

OBJECTIVES: This study draws on qualitative insights on the barriers and facilitators to HIV testing, as well as perceptions of HIV self-testing (HIVST), to propose a framework to understand not only the benefits but also potential knock-on implications of introducing HIVST in the context of other STI testing. METHODS: We conducted semistructured, in-depth interviews with 30 gay, bisexual and other men who have sex with men aged 18 and 39 years old in Singapore. Interview topics included barriers and facilitators to HIV and other STI testing, as well as perceptions of HIVST. Interviews were audio-recorded, transcribed, coded and analysed using thematic analysis. RESULTS: For HIV testing, participants cited the perceived risk of acquiring, susceptibility to and symptoms of HIV as internal motivators, while social influence and accessibility of HIV testing services were external motivators. For STI testing, perceived symptoms and partner notification of STI were reported as internal and external motivators, respectively. Availability of bundle tests, starting a new relationship and instances of mandatory testing motivated both simultaneous HIV and other STI testing. The fear of a positive diagnosis and lack of confidentiality were cited as internal and external barriers to HIV testing, respectively, while low perceived severity of other STI and the cost of STI tests were cited as internal and external barriers to other STI testing, respectively. We identified pathways to HIV and other STI testing and discussed how the introduction of HIVST may reduce opportunities for other STI testing. CONCLUSIONS: The findings of this study suggest that introducing HIVST might weaken linkages to other STI testing if alternative strategies of promoting other STI testing are not simultaneously implemented. We recommend that future interventions address both the risks of HIV and other STI simultaneously, and that structural interventions promoting HIV and other STI preventions be balanced accordingly.


Assuntos
Infecções por HIV/diagnóstico , Infecções Sexualmente Transmissíveis/diagnóstico , Adulto , Medo , Infecções por HIV/epidemiologia , Infecções por HIV/psicologia , Homossexualidade Masculina/psicologia , Homossexualidade Masculina/estatística & dados numéricos , Humanos , Masculino , Motivação , Pesquisa Qualitativa , Autoteste , Minorias Sexuais e de Gênero , Infecções Sexualmente Transmissíveis/epidemiologia , Infecções Sexualmente Transmissíveis/psicologia , Singapura/epidemiologia , Adulto Jovem
6.
Sensors (Basel) ; 21(8)2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33918695

RESUMO

During the training phase of the supervised learning, it is not feasible to collect all the datasets of labelled data in an outdoor environment for the localization problem. The semi-supervised transfer learning is consequently used to pre-train a small number of labelled data from the source domain to generate a kernel knowledge for the target domain. The kernel knowledge is transferred to a target domain to transfer some unlabelled data into the virtual labelled data. In this paper, we have proposed a new outdoor localization scheme using a semi-supervised transfer learning for LoRaWANs. In the proposed localization algorithm, a grid segmentation concept is proposed so as to generate a number of virtual labelled data through learning by constructing the relationship of labelled and unlabelled data. The labelled-unlabelled data relationship is repeatedly fine-tuned by correctly adding some more virtual labelled data. Basically, the more the virtual labelled data are added, the higher the location accuracy will be obtained. In the real implementation, three types of signal features, RSSI, SNR, and timestamps, are used for training to improve the location accuracy. The experimental results illustrate that the proposed scheme can improve the location accuracy and reduce the localization error as opposed to the existing outdoor localization schemes.

7.
Int J Mol Sci ; 22(16)2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34445499

RESUMO

Xenoestrogens and phytoestrogens are referred to as "foreign estrogens" that are produced outside of the human body and have been shown to exert estrogen-like activity. Xenoestrogens are synthetic industrial chemicals, whereas phytoestrogens are chemicals present in the plant. Considering that these environmental estrogen mimics potentially promote hormone-related cancers, an understanding of how they interact with estrogenic pathways in human cells is crucial to resolve their possible impacts in cancer. Here, we conducted an extensive literature evaluation on the origins of these chemicals, emerging research techniques, updated molecular mechanisms, and ongoing clinical studies of estrogen mimics in human cancers. In this review, we describe new applications of patient-derived xenograft (PDX) models and single-cell RNA sequencing (scRNA-seq) techniques in shaping the current knowledge. At the molecular and cellular levels, we provide comprehensive and up-to-date insights into the mechanism of xenoestrogens and phytoestrogens in modulating the hallmarks of cancer. At the systemic level, we bring the emerging concept of window of susceptibility (WOS) into focus. WOS is the critical timing during the female lifespan that includes the prenatal, pubertal, pregnancy, and menopausal transition periods, during which the mammary glands are more sensitive to environmental exposures. Lastly, we reviewed 18 clinical trials on the application of phytoestrogens in the prevention or treatment of different cancers, conducted from 2002 to the present, and provide evidence-based perspectives on the clinical applications of phytoestrogens in cancers. Further research with carefully thought-through concepts and advanced methods on environmental estrogens will help to improve understanding for the identification of environmental influences, as well as provide novel mechanisms to guide the development of prevention and therapeutic approaches for human cancers.


Assuntos
Neoplasias/tratamento farmacológico , Neoplasias/prevenção & controle , Fitoestrógenos/uso terapêutico , Análise de Célula Única/métodos , Animais , Biomarcadores Tumorais/genética , Ensaios Clínicos como Assunto , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Neoplasias/genética , Fitoestrógenos/farmacologia , Análise de Sequência de RNA , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Nonlinear Dyn ; 106(2): 1311-1323, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34248280

RESUMO

Although deterministic compartmental models are useful for predicting the general trend of a disease's spread, they are unable to describe the random daily fluctuations in the number of new infections and hospitalizations, which is crucial in determining the necessary healthcare capacity for a specified level of risk. In this paper, we propose a stochastic SEIHR (sSEIHR) model to describe such random fluctuations and provide sufficient conditions for stochastic stability of the disease-free equilibrium, based on the basic reproduction number that we estimated. Our extensive numerical results demonstrate strong threshold behavior near the estimated basic reproduction number, suggesting that the necessary conditions for stochastic stability are close to the sufficient conditions derived. Furthermore, we found that increasing the noise level slightly reduces the final proportion of infected individuals. In addition, we analyze COVID-19 data from various regions worldwide and demonstrate that by changing only a few parameter values, our sSEIHR model can accurately describe both the general trend and the random fluctuations in the number of daily new cases in each region, allowing governments and hospitals to make more accurate caseload predictions using fewer compartments and parameters than other comparable stochastic compartmental models.

9.
Oncologist ; 25(5): 438-446, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32048768

RESUMO

INTRODUCTION: Objective response rates (ORR) appear to be higher in melanoma patients who develop immune-related adverse events (irAEs), but whether there is a similar association between irAEs and survival remains unknown. MATERIALS AND METHODS: Patients with advanced melanoma treated with single-agent pembrolizumab or nivolumab in the province of Alberta from June 2014 to May 2017 were identified through the provincial pharmacy database. Chart review identified and categorized all irAEs that occurred while on anti-programmed cell death protein 1 (PD-1) checkpoint inhibitors. The primary objective was to compare overall survival (OS) with patients who developed any irAEs versus those who did not. Secondary outcomes included progression-free survival (PFS) and ORR. RESULTS: Among 186 patients, any-grade and grade ≥3 irAEs occurred in 88 (47%) and 27 (15%) patients, respectively; one patient died of pneumonitis. In a landmark analysis excluding patients who died within the first 12 weeks, the median follow-up was 24 months, 20 months in patients without any irAEs and 26 months in patients with irAEs (p = .006). Median OS was 39 versus 23 months (hazard ratio [HR], 0.46; p = .001) for any irAE and no irAE, respectively, and median OS not reached versus 29 months for grade ≥3 irAEs and no grade ≥3 irAEs, respectively. In multivariate analysis, elevated lactate dehydrogenase correlated with reduced OS (HR, 2.34; p = .001), whereas each additional cycle of treatment received (HR, 0.94; p < .001) and development of grade ≥3 irAEs (HR, 0.29, p = .024) were significantly associated with longer OS. CONCLUSION: Anti-PD-1-associated grade ≥3 irAEs in patients with advanced melanoma is associated with better patient outcomes, including overall survival. IMPLICATIONS FOR PRACTICE: Previous prospective randomized clinical trials demonstrate improved response rates in patients with melanoma who develop select adverse events. The current population-based real-world study in advanced melanoma reports an association with anti-programmed cell death protein 1 (PD-1)-induced grade ≥3 immune-related adverse events (irAEs) and better patient outcomes, including overall survival. These results suggest that irAEs may be a manifestation of a patient's ability to mount a systemic immune response from PD-1-directed therapies, which may be associated with therapeutic benefit. The finding of irAEs coinciding with clinical benefit from these therapies supposes that these events are, by and large, unavoidable, and the critical management of irAEs remains essential for optimizing patient outcomes.


Assuntos
Antineoplásicos Imunológicos , Melanoma , Antineoplásicos Imunológicos/efeitos adversos , Humanos , Imunoterapia/efeitos adversos , Melanoma/tratamento farmacológico , Estudos Prospectivos , Estudos Retrospectivos
10.
Anal Chem ; 92(11): 7556-7564, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32366088

RESUMO

Understanding the complex relationships between genomics, transcriptomics, and proteomics requires the development of more sensitive and rapid methods of multiplexed protein analysis. This is necessary to understand the relationship between cellular responses to environmental stresses, disease progression, and/or drug treatment; however, most methods are limited by low sensitivity, nonspecificity, and minimal multiplexing capacity. To more fully explore the relationship between multiple cellular pathways, we have developed a novel antibody-based multiplex assay using inductively coupled plasma mass spectrometry (ICP-MS), which we term metal-assisted protein quantitation (MAPq). MAPq utilizes lanthanide-conjugated antibodies to simultaneously quantify up to 35 proteins with low pg/mL sensitivity. This method is especially advantageous for low-abundance proteins, a significant limitation of many multiplex MS methods. We observed a limit of detection of 0.5 pg/mL and a limit of quantitation of 5 pg/mL with virtually no background signal. We applied this method to both cultured cells and mouse tissues to investigate changes in low-abundance nuclear and cytoplasmic proteins following drug or environmental stresses. MAPq was found to be at least 10 times more sensitive than Western blots and could detect quantitative changes in protein expression not readily observed using conventional approaches.


Assuntos
Anticorpos/análise , Elementos da Série dos Lantanídeos/química , Compostos Organometálicos/química , Linhagem Celular Tumoral , Humanos , Espectrometria de Massas
11.
Arch Biochem Biophys ; 692: 108511, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32710883

RESUMO

(-)-Epigallocatechin-3-gallate (EGCG), the most abundant catechin component in green tea, has been reported to attenuate age-associated insulin resistance, lipogenesis and loss of muscle mass through restoring Akt activity in skeletal muscle in our previous and present studies. Accumulated data has suggested that polyphenols regulate signaling pathways involved in aging process such as inflammation and oxidative stress via modulation of miRNA expression. Here we found that miRNA-486-5p was significantly decreased in both aged senescence accelerated mouse-prone 8 (SAMP8) mice and late passage C2C12 cells. Thus, we further investigated the regulatory effect of EGCG on miRNA-486-5p expression in age-regulated muscle loss. SAMP8 mice were fed with chow diet containing without or with 0.32% EGCG from aged 32 weeks for 8 weeks. Early passage (<12 passages) and late passage (>30 passages) of C2C12 cells were treated without or with EGCG at concentrations of 50 µM for 24h. Our data showed that EGCG supplementation increased miRNA-486-5p expression in both aged SAMP8 mice and late passage C2C12 cells. EGCG stimulated AKT phosphorylation and inhibited FoxO1a-mediated MuRF1 and Atrogin-1 transcription via up-regulating the expression of miR-486 in skeletal muscle of 40-wk-old SAMP8 mice as well as late passage C2C12 cells. In addition, myostatin expression was increased in late passage C2C12 cells and anti-myostatin treatment upregulated the expression of miR-486-5p. Our results identify a unique mechanism of a dietary constituent of green tea and suggest that use of EGCG or compounds derived from it attenuates age-associated muscle loss via myostatin/miRNAs/ubiquitin-proteasome signaling.


Assuntos
Envelhecimento/metabolismo , Catequina/análogos & derivados , Regulação da Expressão Gênica/efeitos dos fármacos , MicroRNAs/metabolismo , Proteínas Musculares/biossíntese , Atrofia Muscular/metabolismo , Miostatina/biossíntese , Envelhecimento/efeitos dos fármacos , Envelhecimento/genética , Envelhecimento/patologia , Animais , Catequina/química , Catequina/farmacologia , Linhagem Celular , Camundongos , Camundongos Transgênicos , MicroRNAs/genética , Proteínas Musculares/genética , Atrofia Muscular/genética , Atrofia Muscular/patologia , Miostatina/genética , Chá/química
12.
Biogerontology ; 21(3): 367-380, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32130580

RESUMO

The senescence-accelerated mouse (SAM) prone 8 (SAMP8) has been demonstrated for muscular aging research including sarcopenia, but its underlying mechanisms remain scarce. Physiological indices and histology of skeletal muscle were analyzed in SAMP8 mice at different ages. SAMP8 mice exhibited typical features of sarcopenia at 40 weeks of age and were more time-efficient than that at 88 weeks of age in bothSAM resistant 1 (SAMR1) and C57BL/6 mice. Increase in FoxO3a-mediated transcription of Atrogin-1 and MuRF1 and decrease in phosphorylated mTOR/P70s6k were observed at week 40 in SAMP8 mice. High oxidative stress was observed from week 24 and persisted to week 40 in SAMP8 mice evidenced by overexpression of protein carbonyl groups and reduced activities of CAT, SOD, and GPx. Downregulation of genes involved in mitochondrial biogenesis (PGC-1α, Nrf-1, Tfam, Ndufs8, and Cox5b) and in mitochondrial dynamics fission (Mfn2 and Opa1) from week 24 indicated dysregulation of mitochondrial quality control in SAMP8 mice. Impaired autophagic flux was observed in SAMP8 mice evidenced by elevated Atg13 and LC3-II accompanied with the accumulation of P62 and LAMP1. Increases in inflammatory factors (IL-6 and MCP-1), adipokines (leptin and resistin), and myostatin in serum at week 32 and decline in Pax7+ satellite cell resided next to muscle fibers at week 24 implied that muscle microenvironment contributed to the progression of sarcopenia in SAMP8 mice. Our data suggest that early alterations of mitochondrial quality control and autophagic flux worsen muscle microenvironment prior to the onset of sarcopenia.


Assuntos
Envelhecimento , Mitocôndrias , Sarcopenia , Animais , Camundongos , Camundongos Endogâmicos C57BL , Músculo Esquelético/metabolismo , Sarcopenia/metabolismo
13.
Nutr Neurosci ; 22(12): 840-849, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29595091

RESUMO

Objectives: This study evaluated the bioactive composition of tempeh products and examined the effects of tempeh on BV-2 microglial cell cytotoxicity, neurotrophic effects, and expression of inflammatory genes.Methods: Tempeh products included soybean fermented by Rhizopus, soybean fermented through cocultivation with Rhizopus and Lactobacillus, and red bean fermented through cocultivation with Rhizopus and Lactobacillus (RT-C). We analyzed the bioactive contents of tempeh extracts and evaluated the effects of tempeh water extract on lipopolysaccharide (LPS)-treated BV-2 cells.Results: The results showed that RT-C water extract had the highest concentrations of γ-aminobutyric acid (GABA) and anthocyanin. The tempeh water extracts, especially RT-C, reduced the formation of LPS-induced reactive oxygen species, downregulated the levels of nitric oxide synthase and phospho-cyclic-AMP response element-binding protein, and upregulated the expression of brain-derived neurotrophic factor (BDNF).Discussion: Our data demonstrate that RT-C has the highest concentrations of GABA and anthocyanin, more effectively reduces oxidative stress and inflammation, and increases the expression of BDNF in LPS-induced BV-2 cells.


Assuntos
Lipopolissacarídeos/farmacologia , Microglia/efeitos dos fármacos , Fármacos Neuroprotetores/administração & dosagem , Extratos Vegetais/farmacologia , Alimentos de Soja , Animais , Antocianinas/análise , Antocianinas/farmacologia , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Fator Neurotrófico Derivado do Encéfalo/análise , Linhagem Celular , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/análise , Fermentação , Lactobacillus/metabolismo , Camundongos , Óxido Nítrico Sintase Tipo II/análise , Extratos Vegetais/química , Rhizopus/metabolismo , Glycine max , Ácido gama-Aminobutírico/análise , Ácido gama-Aminobutírico/farmacologia
15.
Health Care Manag Sci ; 21(4): 554-572, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28755176

RESUMO

An earlier article, inspired by overflow models in telecommunication systems with multiple streams of telephone calls, proposed a new analytical model for a network of intensive care units (ICUs), and a new patient referral policy for such networks to reduce the blocking probability of external emergency patients without degrading the quality of service (QoS) of canceled elective operations, due to the more efficient use of ICU capacity overall. In this work, we use additional concepts and insights from traditional teletraffic theory, including resource sharing, trunk reservation, and mutual overflow, to design a new patient referral policy to further improve ICU network efficiency. Numerical results based on the analytical model demonstrate that our proposed policy can achieve a higher acceptance level than the original policy with a smaller number of beds, resulting in improved service for all patients. In particular, our proposed policy can always achieve much lower blocking probabilities for external emergency patients while still providing sufficient service for internal emergency and elective patients. In addition, we provide new accurate and computationally efficient analytical approximations for QoS evaluation of ICU networks using our proposed policy. We demonstrate numerically that our new approximation method yields more accurate, robust and conservative results overall than the traditional approximation. Finally, we demonstrate how our proposed approximation method can be applied to solve resource planning and optimization problems for ICU networks in a scalable and computationally efficient manner.


Assuntos
Eficiência Organizacional , Unidades de Terapia Intensiva/organização & administração , Admissão do Paciente , Encaminhamento e Consulta/organização & administração , Teoria de Sistemas , Comportamento Cooperativo , Número de Leitos em Hospital , Humanos , Transferência de Pacientes/organização & administração , Qualidade da Assistência à Saúde/organização & administração
16.
Behav Res Methods ; 50(5): 1763-1777, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-28779457

RESUMO

Here we report on MELD-SCH (MEgastudy of Lexical Decision in Simplified CHinese), a dataset that contains the lexical decision data of 1,020 one-character, 10,022 two-character, 949 three-character, and 587 four-character simplified Chinese words obtained from 504 native Chinese users. It also includes a number of word-level and character-level variables. Analyses showed that the reliability of the dataset is satisfactory, as indicated by split-half correlations and comparisons with other datasets. Item-based regression showed that both word-level and character-level variables contributed significantly to the reaction times and error rates of lexical decision. Moreover, we discovered a U-shape relationship between word-length and reaction times, which has not been reported in Chinese before. MELD-SCH can facilitate research in Chinese word recognition by providing high quality normative data and information of different linguistic variables. It also encourages researchers to extend their empirical findings, which are mostly based on one-character and two-character words, to words of different lengths.


Assuntos
Linguística/métodos , Processos Mentais , Psicolinguística/métodos , Semântica , Vocabulário , Povo Asiático , Pesquisa Comportamental/métodos , Coleta de Dados , Tomada de Decisões , Feminino , Humanos , Masculino , Tempo de Reação , Reconhecimento Psicológico , Reprodutibilidade dos Testes , Tamanho da Amostra , Adulto Jovem
17.
Int Tinnitus J ; 22(1): 84-88, 2018 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-29993223

RESUMO

OBJECTIVES: The function of γ-amino butyric acid receptor (GR) was related with tinnitus. But, the effects of Spirulina platensis water extract (SP) on the mRNA expression of GRAß3 in mice with tinnitus were still unclear. METHOD: Eighteen SAMP8 mice were divided into the control group (intraperitoneal injection of saline, once per day), the tinnitus group (intraperitoneal injection of salicylate, 300 mg/kg body weight once per day), and the spirulina group [intraperitoneal injection of salicylate, 300 mg/kg body weight and oral SP supplementation (1000 mg/kg body weight) once per day]. Effects of SP on the mRNA expression of GRAß3 in the cochlea and brain of mice were studied for 4 days. RESULTS: Compared to the control group, the tinnitus group had significantly higher tinnitus scores and lower mRNA expression of GRAß3 gene in the cochlear, brainstem, hippocampus and parahippocampus, temporal lobes, and the frontal lobes. On the other hand, the spirulina group had significantly lower tinnitus scores and higher GRAß3 gene expression than the tinnitus group in all tested areas. CONCLUSION: SP could reduce salicylate-induced tinnitus possibly via increasing the salicylate-induced down-regulation of GRAß3 gene expression.


Assuntos
RNA Mensageiro/metabolismo , Receptores de GABA-B/genética , Receptores de GABA , Spirulina/química , Zumbido/genética , Animais , Encéfalo/metabolismo , Cóclea/metabolismo , Regulação para Baixo , Expressão Gênica , Camundongos , Receptores de GABA-B/metabolismo , Ácido Salicílico , Zumbido/induzido quimicamente , Zumbido/metabolismo
18.
Chem Res Toxicol ; 30(2): 689-698, 2017 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-28107623

RESUMO

More precise identification and treatment monitoring of prediabetic/diabetic individuals will require additional biomarkers to complement existing diagnostic tests. Candidates include hyperglycemia-induced adducts such as advanced glycation end products (AGEs) of proteins, lipids, and DNA. The potential for DNA-AGEs as diabetic biomarkers was examined in a longitudinal study using the Leprdb/db animal model of metabolic syndrome. The DNA-AGE, N2-(1-carboxyethyl)-2'-deoxyguanosine (CEdG) was quantified by mass spectrometry using isotope dilution from the urine and tissue of hyperglycemic and normoglycemic mice. Hyperglycemic mice (fasting plasma glucose, FPG, ≥ 200 mg/dL) displayed a higher median urinary CEdG value (238.4 ± 112.8 pmol/24 h) than normoglycemic mice (16.1 ± 11.8 pmol/24 h). Logistic regression analysis revealed urinary CEdG to be an independent predictor of hyperglycemia. Urinary CEdG was positively correlated with FPG in hyperglycemic animals and with HbA1c for all mice. Average tissue-derived CEdG was also higher in hyperglycemic mice (18.4 CEdG/106 dG) than normoglycemic mice (4.4 CEdG/106 dG). Urinary CEdG was significantly elevated in Leprdb/db mice relative to Leprwt/wt, and tissue CEdG values increased in the order Leprwt/wt < Leprwt/db < Leprdb/db. These data suggest that urinary CEdG measurement may provide a noninvasive quantitative index of glycemic status and augment existing biomarkers for the diagnosis and monitoring of diabetes.


Assuntos
DNA/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Modelos Animais de Doenças , Produtos Finais de Glicação Avançada/metabolismo , Animais , Camundongos , Camundongos Endogâmicos C57BL
19.
Lipids Health Dis ; 16(1): 12, 2017 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-28095860

RESUMO

Atherosclerosis represents a significant cause of morbidity and mortality in both the developed and developing countries. Animal models of atherosclerosis have served as valuable tools for providing insights on its aetiology, pathophysiology and complications. They can be used for invasive interrogation of physiological function and provide a platform for testing the efficacy and safety of different pharmacological therapies. Compared to studies using human subjects, animal models have the advantages of being easier to manage, with controllable diet and environmental risk factors. Moreover, pathophysiological changes can be induced either genetically or pharmacologically to study the harmful effects of these interventions. There is no single ideal animal model, as different systems are suitable for different research objectives. A good understanding of the similarities and differences to humans enables effective extrapolation of data for translational application. In this article, we will examine the different mouse models for the study and elucidation of the pathophysiological mechanisms underlying atherosclerosis. We also review recent advances in the field, such as the role of oxidative stress in promoting endoplasmic reticulum stress, mitochondrial dysfunction and mitochondrial DNA damage, which can result in vascular inflammation and atherosclerosis. Finally, novel therapeutic approaches to reduce vascular damage caused by chronic inflammation using microRNA and nano-medicine technology, are discussed.


Assuntos
Aterosclerose/fisiopatologia , Modelos Animais de Doenças , Estresse do Retículo Endoplasmático , Estresse Oxidativo , Animais , Aterosclerose/tratamento farmacológico , Aterosclerose/etiologia , Dano ao DNA , DNA Mitocondrial , Inflamação/tratamento farmacológico , Camundongos
20.
Int J Audiol ; 56(2): 92-98, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27686009

RESUMO

OBJECTIVE: This study was conducted to evaluate the speech perception of Malaysian Chinese adults using the Taiwanese Mandarin HINT (MHINT-T) and the Malay HINT (MyHINT). DESIGN: The MHINT-T and the MyHINT were presented in quiet and noise (front, right and left) conditions under headphones. Results for the two tests were compared with each other and with the norms for each test. STUDY SAMPLE: Malaysian Chinese native speakers of Mandarin (N = 58), 18-31 years of age with normal hearing. RESULTS: On average, subjects demonstrated poorer speech perception ability than the normative samples for these tests. Repeated measures ANOVA showed that speech reception thresholds (SRTs) were slightly poorer on the MHINT-T than on the MyHINT for all test conditions. However, normalized SRTs were poorer by 0.6 standard deviations for MyHINT as compared with MHINT-T. CONCLUSIONS: MyHINT and MHINT-T can be used as norm-referenced speech perception measures for Mandarin-speaking Chinese in Malaysia.


Assuntos
Estimulação Acústica/métodos , Audiometria da Fala/métodos , Multilinguismo , Ruído/efeitos adversos , Mascaramento Perceptivo , Percepção da Fala , Adolescente , Adulto , Limiar Auditivo , Feminino , Audição , Humanos , Masculino , Valor Preditivo dos Testes , Inteligibilidade da Fala , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA