19341 research outputs found
Sort by
A contribuição da gestão do conhecimento do consumidor para o desenvolvimento da capacidade de sensing : um estudo de caso em uma empresa de serviços do setor imobiliário.
No full textPrograma de Pós-Graduação em Engenharia de Produção. Departamento de Engenharia de Produção, Instituto de Ciências Exatas e Aplicadas, Universidade Federal de Ouro Preto.Diante do crescente aumento da competitividade entre as empresas, identificar oportunidades é essencial para as empresas se destacarem e sobreviverem no mercado. Em virtude disso, é de fundamental importância levar em consideração a visão dos consumidores para melhorar a percepção de mercado das organizações. Em vista disso, este trabalho objetiva propor um modelo empírico, apresentando como a empresa de serviços do setor imobiliário, objeto de estudo, monitora informações sobre os consumidores e, a partir disso, desenvolve a capacidade de sensing para se ajustar ao ambiente. Para tanto, foi realizado um levantamento bibliográfico sobre capacidades dinâmicas, gestão do conhecimento e consumidor, e identificaram-se limitações que elucidam uma lacuna nos trabalhos publicados, uma vez que não abordam como o conhecimento adquirido por meio de pesquisas sobre o consumidor é monitorado e gerenciado, visando desenvolver capacidades dinâmicas. Sendo assim, a metodologia adotada é de cunho qualitativo e foi utilizado o estudo de caso como método. Foram realizadas entrevistas semiestruturadas como instrumento de coleta de dados. Por fim, para a análise dos dados foi utilizada a técnica de análise de conteúdo. Como resultado, foi proposto um modelo apresentando a interdependência entre as atividades de sensing e o processo de gestão do conhecimento, caracterizando uma coevolução. O modelo incorpora informações e práticas utilizadas pela empresa desde a captação de dados externos até o processo de aplicação do conhecimento. Sendo assim, à medida que a organização aprimora a capacidade de sensing e o desenvolvimento das demais atividades de gestão do conhecimento, as capacidades dinâmicas também evoluem.Giving the increasing competitiveness among companies, identifying opportunities is essential for companies to stand out and survive in the market. Therefore, it is of fundamental importance to take into account the consumer's vision to improve the market perception of organizations. In view of this, this work aims to propose an empirical model, presenting how the real estate service company, the object of study, monitors information about consumers and, from this, develops the capacity to sense to adapt to the environment. To this end, a bibliographic survey was carried out on dynamic capabilities, knowledge management, and consumers, and limitations were identified that elucidate a gap in the published works, since they do not address how the knowledge acquired through consumer research is monitored and managed, aiming to develop dynamic capabilities. Thus, the methodology adopted is qualitative and the case study was used as a method. Semi-structured interviews were conducted as a data collection instrument. Finally, for data analysis, the content analysis technique was used. As a result, a model was proposed presenting the interdependence between sensing activities and the knowledge management process, characterizing a coevolution. The model incorporates information and practices used by the company from the collection of external data to the process of applying knowledge. Thus, as the organization improves its sensing capacity and the development of other knowledge management activities, dynamic capabilities also evolve
PLA-b-SMA as an amphiphilic diblock copolymer for encapsulation of lipophilic cargo.
No full textThe encapsulation of active pharmaceutical ingredients (APIs) within drug
delivery systems such as polymeric nanoparticles (PNPs) vastly improves the
therapeutic efficiency of the incorporated APIs. PNPs synthesized using
amphiphilic block copolymers are efficient drug delivery systems as the
hydrophobic block facilitates the encapsulation of lipophilic components and
the hydrophilic block constitutes the hairy corona of the PNP that stabilizes
the nanocarriers against aggregation in solution. Poly(styrene-alt-maleic acid)
(SMA) is an attractive polymer for the hydrophilic corona of PLA-based
nanoparticles as it allows for post polymerization functionalization and aids in
the prevention of NP aggregation. The synthesis of a novel PLA-b-SMA block
copolymer, via sequential ring opening polymerization (ROP) and reversible
addition–fragmentation chain transfer (RAFT) polymerization, is presented.
PLA macro-CTAs, synthesized via ROP, can be chain extended via RAFT
copolymerization of styrene and maleic anhydride to yield PLA-b-SMAnh and
via RAFT polymerization of N-vinylpyrrolidone to yield PLA-b-PVP block
copolymers. Controlled hydrolysis of the anhydride moieties converts
PLA-b-SMAnh into PLA-b-SMA. Monodisperse PLA-b-SMA and PLA-b-PVP
nanoparticles (NPs) ranging in diameter between 60 and 220 nm are prepared.
The lipophilic fluorescent dye DiI is encapsulated within the NPs successfully
and these fluorescent NPs are used in a preliminary cell uptake study
Planejamento, síntese e avaliação citotóxica de novas chalconas derivadas do 2-METOXI-4-PROPILFENOL, a partir da otimização estrutural de um composto hit.
No full textPrograma de Pós-Graduação em Ciências Farmacêuticas. Escola de Farmácia, Universidade Federal de Ouro Preto.O câncer representa a segunda maior causa de mortes no Brasil e no mundo e a busca por novas
terapias para esta doença é um desafio constante, em vista da agressividade e toxicidade
associadas aos tratamentos disponíveis. Atualmente existem diversos fármacos disponíveis para
o tratamento do câncer porém, apesar do seu objetivo principal consistir na destruição das
células neoplásicas, estes atuam de forma não seletiva, o que consiste na principal limitação do
tratamento, justificando a busca por novas substâncias mais potentes e seletivas. No âmbito das
substâncias naturais biologicamente ativas, as chalconas, flavonoides de cadeia aberta contendo
dois anéis aromáticos unidos por um sistema α,β-insaturado, são amplamente distribuídas no
reino vegetal, e exibem um diversificado espectro de atividades biológicas, dentre elas,
potencial antitumoral. Recentemente nosso grupo relatou a síntese de uma série de chalconas
inéditas derivadas do eugenol e análogos, dentre as quais uma delas (substância I, derivada do
2-metoxi-4-propil-fenol), se destacou quanto ao seu potencial citotóxico, sendo mais de duas
vezes mais potente e três vezes menos tóxica que a doxorrubicina contra células de
hepatocarcinoma humano (HepG2). Considerando estratégias de modificações moleculares,
como hibridação molecular e bioisosterismo, realizou-se neste trabalho o planejamento e
síntese de novas chalconas derivadas da chalcona I e a avaliação do seu potencial citotóxico
contra diferentes linhagens de células tumorais. Todas as substâncias sintetizadas foram
devidamente caracterizadas por espectroscopia de ressonância magnética nuclear (RMN) de 1H
e 13C e sua atividade citotóxica avaliada contra as linhagens tumorais HeLa, HepG2, T24 e
TOV-21G, além da linhagem humana sadia MRC-5. Dentre os derivados ativos, a chalcona 19
apresentou a atividade mais promissora, sendo ativa contra todas as linhagens tumorais
avaliadas, com valores de CC50 de 7,05 μM (HeLa), 5,61 μM (HepG2), 6,60 μM (TOV-21G) e
2,08 μM (T24), e índice de seletividade até 250 vezes maior que a doxorrubicina, fármaco
utilizado como controle positivo nos testes realizados, para a linhagem TOV-21G.Cancer represents the second cause of death in Brazil and worldwide, and the pursuit of new
therapies for this disease remains a constant challenge, given the aggressiveness and toxicity
associated with available treatments. While various drugs are currently accessible for cancer
treatment, their non-selective mode of action, despite aiming at neoplastic cell destruction,
remains the primary limitation of treatment, thus justifying the search for more potent and
selective compounds. Within the biologically active natural substances, chalcones, open-chain
flavonoids with two aromatic rings linked by an α,β-unsaturated system, are widely distributed
in the plant kingdom and exhibit a diverse spectrum of biological activities, including potential
antitumor effects. Recently, our group reported the synthesis of a series of novel chalcones
derived from eugenol and its analogs. Among these, one compound (Substance I, derived from
2-methoxy-4-propylphenol) stood out for its cytotoxic potential, being more than twice as
potent and three times less toxic than doxorubicin against human hepatocarcinoma cells
(HepG2). In consideration of molecular modification strategies, such as molecular
hybridization and bioisosterism, this work entails the design and synthesis of new chalcones
derived from chalcone I, along with an evaluation of their cytotoxic potential against different
cancer cell lines. All synthesized compounds were appropriately characterized using 1H and 13C
nuclear magnetic resonance (NMR) spectroscopy, and their cytotoxic activity was assessed
against the tumor cell lines HeLa, Hep-G2, T24, and TOV-21G, as well as the healthy human
cell line MRC-5. Among the active derivatives, Chalcone 19 exhibited the most promising
activity, being effective against all evaluated tumor cell lines, with CC50 values of 7.05 μM
(HeLa), 5.61 μM (HepG2), 6.60 μM (TOV-21G), and 2.08 μM (T24), and a selectivity index
up to 250 times higher than doxorubicin, the positive control drug used in the tests, for the
TOV-21G cell line
Violência de gênero na docência : moral, hierarquia e poder na universidade pública.
No full textPrograma de Pós-Graduação em Educação. Departamento de Educação, Instituto de Ciências Humanas e Sociais, Universidade Federal de Ouro Preto.Esta tese partiu dos testemunhos de cinco mulheres cis, incluindo a autora, sobre violências
institucionais vividas no exercício da docência do ensino superior em universidades públicas
brasileiras. Os convites foram feitos por amostra não probabilista intencional. Usamos no
referencial teórico conceitos ligados a violência, relações de poder, discurso e verdade de
Michel Foucault; poder maquínico de Gilles Deleuze e Félix Guattari e, a partir da leitura de
Marie-France Hirigoyen, percebemos que o que estávamos estudando não era assédio moral e,
usando diversos autores e legislações, passamos a utilizar tortura moral para definir as práticas
de violência cometidas pelo Estado e seus agentes que se repetem ao longo do tempo e têm por
objetivo mudar as crenças, os discursos e os modos de ser de suas vítimas (seu eu) nos processos
de gestão do trabalho nas universidades públicas brasileiras. Nosso objetivo geral era
compreender como se estabelecem as relações de poder e resistência que fazem com que
mulheres vivenciem cerceamentos e violências no exercício da docência do Ensino Superior
em universidades públicas brasileiras. Sobre isso, chegamos à compreensão de que há um
dispositivo que opera via tortura moral, a partir do qual essas relações de poder se estabelecem
como mecanismos de correção. Os objetivos específicos previam analisar relações entre moral
e hierarquia na produção de cerceamento e violências contra mulheres no exercício da docência
no Ensino Superior em universidades públicas brasileiras (e concluímos que tanto os códigos
morais compartilhados, quanto a hierarquia são usados para validar as práticas de violência
institucional); verificar se há regularidades discursivas sobre gênero, sexualidades, questões
étnico-raciais e de classe entre diferentes docentes ao narrarem processos de violência sofridos
no exercício da docência em instituições públicas de Ensino Superior (as encontramos, mas
encontramos também outras, como as ligadas ao uso das maternidades para validar violências);
e identificar relações entre as violências narradas com códigos morais de gênero, sexualidades,
étnico-raciais e classe em instituições públicas de Ensino Superior (o que foi possível ao
analisar o uso dos códigos morais compartilhados na validação das violências institucionais que
compõem práticas de tortura moral). Dessa investigação resultou a tese de que as violências
impostas hierarquicamente a nós são parte de um dispositivo que opera por práticas de tortura
moral, enquanto violência institucional, com o objetivo de que nos adequemos ao que é
considerado apropriado à docência do Ensino Superior, pensada a partir de uma ideia de
universidade criada na lógica moderna, eurocêntrica, caucasiana, heterossexual, cis, elitista e
masculina.This thesis addressed the testimonies of five cis women, including the author’s one, about
institutional violence experienced while they work as professors in Brazilian public
universities. Invitations were made by intentional non-probabilistic sampling. We use in the
theoretical framework concepts related to violence, power relations, discourse and truth by
Michel Foucault; mechanic power of Gilles Deleuze and Félix Guattari and, from reading of
Marie-France Hirigoyen, we realized that what we were studying was not moral harassment
and, using different authors and legislation, we started to use the concept of moral torture to
define the practices of violence committed by the State and its agents, which are repeated over
time and aim at changing the beliefs, discourses and ways of being of their victims (their self)
within work management processes in Brazilian public universities. Our general objective was
to understand how the relations of power and resistance are established in a way that it results
on women experiencing restrictions and violence in the work of higher education teaching in
Brazilian public universities. On this topic, we came to the understanding that there is a
dispositif that operates via moral torture, from which these power relations are established as
correction mechanisms. The specific objectives were to analyze the relationship between
morality and hierarchy in the production of restrictions and violence against women in higher
education teaching in Brazilian public universities (and we concluded that both shared moral
codes and hierarchy are used to validate practices of institutional violence); to verify if there
are discursive regularities on gender, sexualities, ethnic-racial and class issues amongst
different professors when they narrate processes of violence suffered in the exercise of teaching
in public institutions of Higher Education (we found them, but we also found others, such as
those linked to the use of motherhood to validate violence); and to identify relationships
between the violence narrated with moral codes of gender, sexualities, ethnic-racial identities
and class in public institutions of Higher Education (which was possible when analyzing the
use of shared moral codes in the validation of institutional violences that produce practices of
moral torture). This investigation resulted in the thesis that the violence hierarchically imposed
on us is part of a dispositif that operates through practices of moral torture, as institutional
violence, aiming at making us adapt to what is considered appropriate for teaching in Higher
Education according to an idea of university created in a modern, Eurocentric, caucasian,
heterosexual, cis, elitist and male logic
Geochemical multifractal modeling of soil and stream sediment data applied to gold prospectivity mapping of the Pitangui Greenstone Belt, northwest of Quadrilátero Ferrífero, Brazil.
No full textGeochemical mapping has become essential to prospective assessments in both brownfield and greenfield exploration targeting. During the last two decades, several techniques have been applied to the identification of mineralization's geochemical signature. Among these techniques, Hierarchical Clustering (HC) and Principal Component Analysis (PCA) have been widely used. Other techniques, like Multifractal Spectrum (MS) and Local Singularity Mapping (LSM), are efficient in the generation of models suitable to determine the type of database statistical distribution and mapping zones of geochemical enrichment and depletion. We combined these techniques for soil and stream sediment geochemistry and generated two prospective geochemical models for the gold deposits from the Pitangui Greenstone Belt (PGB), located at northwest of Quadrilátero Ferrífero – Brazil. The results of PCA and HC showed a geochemical association of As-Bi-Mo-Sb with gold mineralization in the PGB. According with descriptive statistical analysis, these elements do not display normal or log-normal statistical distribution, which allowed the application of multifractal models on the geochemical mapping. MS technique revealed that all elements associated with gold have a multifractal distribution. In addition, geochemistry data shows that high contents of elements measured in the stream sediment analysis displays greater dispersion when compared to elements of soil geochemistry data, due to their mobility in environmental conditions. We used LSM technique to map geochemical enrichment of the elements associated with gold. The maps were evaluated using the Ground Truth Analysis (GTA) and the results showed a good performance in the identification of prospective zones. The anomalies identified in both geochemical maps showed a strong correlation between geochemical enrichment zones and geological factors that favors gold mineralization. These results bring a new perspective on the distribution of geochemical anomalies using, for the first time, the multifractal geochemical modeling on the PGB. The geochemical maps point to new targets for mineral exploration and contribute significantly for the prospective models of the region
Efficacy of ultrasound vector flow imaging in tracking omnidirectional pulsatile flow.
No full textBackground: Ultrasound vector flow imaging (VFI) shows potential as an emerging non-invasive modality for time-resolved flow mapping. However, its efficacy in tracking multidirectional pulsatile flow with temporal resolvability has not yet been systematically evaluated because of the lack of an appropriate test protocol.
Purpose: We present the first systematic performance investigation of VFI in tracking pulsatile flow in a meticulously designed scenario with time-varying, omnidirectional flow fields (with flow angles from 0◦ to 360◦).
Methods: Ultrasound VFI was performed on a three-loop spiral flow phantom (4 mm diameter; 5 mm pitch) that was configured to operate under pulsatile flow conditions (10 ml/s peak flow rate; 1 Hz pulse rate; carotid pulse shape). The
spiral lumen geometry was designed to simulate recirculatory flow dynamics observed in the heart and in curvy blood vessel segments such as the carotid bulb.The imaging sequence was based on steered plane wave pulsing (−10◦,0◦, +10◦ steering angles; 5 MHz imaging frequency; 3.3 kHz interleaved pulse rep etition frequency). VFI’s pulsatile flow estimation performance and its ability to detect secondary flow were comparatively assessed against flow fields derived
from computational fluid dynamics (CFD) simulations that included considera tion of fluid-structure interactions (FSI). The mean percentage error (MPE) and the coefficient of determination (R2) were computed to assess the correspondence of the velocity estimates derived from VFI and CFD-FSI simulations. In addition, VFI’s efficacy in tracking pulse waves was analyzed with respect to pressure transducer measurements made at the phantom’s inlet and outlet.
Results: Pulsatile flow patterns rendered by VFI agreed with the flow profiles computed from CFD-FSI simulations (average MPE: –5.3%). The shape of the VFI-measured velocity magnitude profile generally matched the inlet flow profile.
High correlation exists between VFI measurements and simulated flow vectors (lateral velocity: R2 = 0.8; axial velocity R2 = 0.89; beam-flow angle: R2 = 0.98; p < 0.0001 for all three quantities). VFI was found to be capable of consistently tracking secondary flow. It also yielded pulse wave velocity (PWV) estimates (5.72 ± 1.02 m/s) that, on average, are within 6.4% of those obtained from pressure transducer measurements (6.11 ± 1.15 m/s).
Conclusion: VFI can consistently track omnidirectional pulsatile flow on a time resolved basis. This systematic investigation serves well as a quality assurance test of VFI
Nitrosyl/Diphenylphosphine/Amino Acid–Ruthenium complexes as inhibitors of MDA-MB-231 breast cancer cells.
No full textHerein, we report on the synthesis and characterization of ruthenium compounds with the
general formula [RuCl(AA-H)(NO)(dppb]PF6
, where AA = glycine (1), L-alanine (2), L-phenylalanine
(3) and L-valine (4), and dppb = 1,4-bis(diphenylphosphine)butane. The complexes were characterized
using elemental analysis, UV/Vis and infrared spectroscopies, 1H, 13C, 31P NMR techniques, and
cyclic voltammetry. Furthermore, the structures of the compounds (1) and (3) were determined using
single-crystal X-ray diffraction. In vitro evaluation of the Ru(II)/nitrosyl/amino acid complexes
revealed their cytotoxic activities against triple-negative MDA-MB-231 breast cancer cells, and against
the non-tumor murine fibroblast cells. All the compounds decreased the percentage of viable cells,
inducing cell death by apoptosis. Additionally, the Ru(II) complexes inhibited the migration of
MDA-MB-231 cells at concentrations lower than 35 µM, after 48 h of exposure. Thus, these complexes
may be promising agents for the treatment of triple-negative MDA-MB-231 breast cancer
Comparação de métodos para avaliar a acurácia da incorporação de dados químicos censurados na análise estatística descritiva de águas subterrâneas contaminadas.
No full textChemical analyses of groundwater often present data sets with censored values, i.e., below the detection limit (LOD).
When the proportion of censored values is significant, descriptive (mean, median and standard deviation) or exploratory
geochemical analysis may be impaired. Ignoring such data or replacing them with some predetermined value is not always
the recommended alternative. Thus, the objective of this research is to investigate the applicability of four methods in
estimating censored chemical data from an area with contaminated groundwater. Three statistical methods were used:
parametric (Maximum Likelihood Estimation, MLE), non-parametric (Kaplan-Meier, KM) and robust (Order Regression
Methods, ROS), in addition to the traditional method of direct replacement of censored data, using LOD/2. The MLE,
assuming a Gaussian distribution of the data (MLE-no), yielded allowable substitution factors, close to 0.5, similarly to the
traditional substitution method (LOD/2). Validation with complete datasets with the same estimation methods and con-
sidering three artificial LOD attested to the good results of MLE-no and ROS with 25% and 50% of censored data, respec-
tively, as well as LOD/2. The first two methods are preferable to LOD/2 as they are statistically based. It is recommended
in future studies that such estimation methods be combined with other geostatistical treatments to improve the spatial
analysis of hydrochemical datasets.Análises químicas da água subterrânea frequentemente apresentam conjuntos de dados com valores censurados, ou seja, abaixo do limite de detecção (LD). Quando a proporção de valores censurados é significativa, a análise geoquímica descritiva (média, mediana e desvio padrão) ou a exploratória podem ser prejudicadas e ignorar tais dados ou substituí-los por algum valor pré-determinado nem sempre é a alternativa recomendável. Assim, neste trabalho objetiva-se investigar a aplicabilidade de quatro métodos na estimativa de dados químicos censurados de uma área com águas subterrâneas contaminadas. Foram empregados três métodos estatísticos: paramétrico (Estimativa de Máxima Verossimilhança, MLE), não paramétrico (Kaplan-Meier, KM) e robusto (Métodos de Regressão na Ordem, ROS), além do método tradicional de substituição direta de dados censurados, utilizando o LD/2. O MLE, admitindo uma distribuição gaussiana dos dados (MLE-no), rendeu fatores de substituição admissíveis, próximos a 0,5, à semelhança do método tradicional de substituição (LD/2). A validação com conjuntos de dados completos com os mesmos métodos de estimativa e considerando três LD artificiais atestou os bons resultados de MLE-no e ROS com 25% e 50% de dados censurados, respectivamente, bem como de LD/2. Acredita-se que os dois primeiros métodos sejam preferíveis ao LD/2, por serem estatisticamente baseados. Recomenda-se em estudos futuros que tais métodos de estimativa sejam combinados com outros tratamentos geoestatísticos para melhorar a análise espacial de conjuntos de dados hidroquímicos
Um estudo longitudinal do treinamento motor com o uso de realidade aumentada.
No full textObjetivo: Apresentar a arquitetura e um protocolo de treinamento com um sistema de
realidade aumentada, proposto para oferecer estímulos visuais para exercícios de ombro.
Métodos: Um sistema de realidade aumentada de baixo custo foi desenvolvido para
fornecer imagem motora através de um braço virtual tridimensional que substitui a
imagem do braço real do usuário na imagem espelhada na tela. Um protocolo foi proposto
e três participantes com Acidente Vascular Cerebral (AVC) crônico com diferentes níveis
de hemiparesia esquerda participaram do estudo longitudinal com o sistema. As medidas
da amplitude de movimento foram obtidas no início e no final de cada sessão. Resultados:
Foram observadas mudanças na faixa de movimento dos participantes com hemiparesia
de nível leve e moderado. A faixa de movimento do participante com paralisia total
(severo) não sofreu alterações. Conclusão: O sistema de realidade aumentada é
adequado para uso com participantes que apresentam diferentes níveis para paralisia do
membro superior.Objective: To present an augmented reality system's architecture and training protocol,
designed to provide visual stimuli for shoulder exercises. Methods: A low-cost mixed
reality system was developed to provide motor imagery through a three-dimensional
virtual arm that replaces the image of the user's real arm in the mirror image on the
computer screen. A protocol was proposed, and three participants with chronic stroke with
different left hemiparesis levels participating the system's longitudinal study. Range of
motion measurements was obtained at the beginning and end of each session. Results:
Changes in participants' range of motion with mild and medium-level hemiparesis were
observed. The participant's range of motion with total (severe) paralysis did not change.
Conclusion: The augmented reality system is suitable for participants with different levels
of upper limb paralysis