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1.
J Biol Chem ; 289(41): 28225-36, 2014 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-25138274

RESUMO

Odontoblasts are a type of terminally differentiated matrix-secreting cells. A number of molecular mechanisms are involved in the differentiation of odontoblasts. Several studies demonstrated that Krüppel-like factor 4 (KLF4) promotes odontoblast differentiation via control of dentin sialophosphoprotein (DSPP). Because nuclear factor I-C (NFIC) is also known to control DSPP, we investigated the relationship between NFIC and KLF4 during odontoblast differentiation. Klf4 mRNA expression was significantly decreased in Nfic(-/-) pulp cells compared with wild type cells. In immunohistochemistry assays, dentin matrix protein 1 (Dmp1), and DSP protein expression was barely observed in Nfic(-/-) odontoblasts and dentin matrix. Nfic bound directly to the Klf4 promoter and stimulated Klf4 transcriptional activity, thereby regulating Dmp1 and DSPP expression during odontoblast differentiation. Nfic or Klf4 overexpression promoted mineralized nodule formation in MDPC-23 cells. In addition, Nfic overexpression also decreased Slug luciferase activity but augmented E-cadherin promoter activity via up-regulation of Klf4 in odontoblasts. Our study reveals important signaling pathways during dentinogenesis: the Nfic-Klf4-Dmp1-Dspp and the Nfic-Klf4-E-cadherin pathways in odontoblasts. Our results indicate the important role of NFIC in regulating KLF4 during dentinogenesis.


Assuntos
Caderinas/genética , Dentinogênese/genética , Proteínas da Matriz Extracelular/genética , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição NFI/genética , Fosfoproteínas/genética , Sialoglicoproteínas/genética , Ameloblastos/citologia , Ameloblastos/metabolismo , Animais , Caderinas/metabolismo , Diferenciação Celular , Dentina/citologia , Dentina/crescimento & desenvolvimento , Dentina/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Genes Reporter , Células HEK293 , Humanos , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/metabolismo , Luciferases/genética , Luciferases/metabolismo , Camundongos , Camundongos Knockout , Fatores de Transcrição NFI/metabolismo , Odontoblastos/citologia , Odontoblastos/metabolismo , Fosfoproteínas/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Ratos , Sialoglicoproteínas/metabolismo , Transdução de Sinais , Transcrição Gênica
2.
Surg Radiol Anat ; 35(6): 463-9, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23296841

RESUMO

PURPOSE: The palatal mucosa is a major donor site for connective tissue in the field of periodontal plastic surgery, since it satisfies both the esthetic and functional demands of patients. The purpose of this study was to use histomorphometric analysis to measure the thicknesses of the palatal mucosa and the lamina propria including the epithelium on cadavers. METHODS: Thirty-four hemimaxillae of cadavers were examined (13 male and 4 female, mean age 57.2 years). Each maxilla was processed for histological sectioning and subsequently for histomorphometric analysis. The thicknesses of the palatal mucosa and the lamina propria including the epithelium were measured at three points starting from the alveolar crest, at intervals of 4 mm, with the aid of Adobe Photoshop. RESULTS: The thickness of the palatal mucosa at the alveolar crest and at 4 and 8 mm below the alveolar crest were 2.51 ± 0.83 (mean ± SD), 2.92 ± 0.80, and 3.62 ± 0.99 mm, respectively, and thus increasing from the alveolar crest toward the midpalatal suture. Conversely, the thicknesses of the lamina propria including the epithelium at these same positions were 2.06 ± 0.70, 1.54 ± 0.48, and 1.28 ± 0.46 mm, respectively, thus decreasing toward the midpalatal suture. CONCLUSIONS: The present results indicate that clinicians need to be particularly careful when harvesting palatal mucosa that is destined to be used as autogenous donor material for connective tissue in periodontal plastic surgery.


Assuntos
Maxila/patologia , Mucosa Bucal/patologia , Mucosa Bucal/transplante , Palato/patologia , Periodonto/cirurgia , Cirurgia Plástica/métodos , Adulto , Idoso , Análise de Variância , Cadáver , Tecido Conjuntivo/transplante , Feminino , Humanos , Imuno-Histoquímica , Masculino , Maxila/cirurgia , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Bucais/métodos , Palato/cirurgia , Periodontia/métodos , Coleta de Tecidos e Órgãos
3.
Artigo em Inglês | MEDLINE | ID: mdl-36361231

RESUMO

COVID-19 has caused tremendous damage to global economies, and similar health crises are expected to happen again. This study tests whether slack resources would enable companies to prepare for such uncertainties. Specifically, we explored the influence of the COVID-19 patient occurrence on corporate financial performance and the buffering effect of financial slacks using Chinese listed companies' data during 2021. We also examined whether this effect differs across firms' financial health and industry. Test results are as follows. First, consistent with the recent studies on pandemics, the degree of COVID-19 prevalence had a negative impact on the Chinese company's financial performance, and slack resources offset this adverse effect. Second, slack's buffering effects appeared mostly in financially constrained companies. Third, such effects mostly appeared in industries vulnerable to the COVID-19 shock. In the business environment of 2021, adapted to COVID-19, our main test result seems to mainly come from companies with a greater need for slack. Our tests imply that, despite differences in the degree of accessibility to resources, excess resources help companies overcome the COVID-19 crisis, which means that firms can more efficiently respond to economic shocks such as COVID-19 if they reserve past profits as free resources. This study contributes to the literature in that there is limited research on the slack resources' buffering effect on the COVID-19 shock and that this study works as a robustness test as it uses data from one of the East Asian regions at a time when the control of COVID-19 was relatively consistent and successful, which can limit the effect of COVID-19 and slacks.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , Pandemias , Organizações , Indústrias , China/epidemiologia
4.
Artigo em Inglês | MEDLINE | ID: mdl-34948842

RESUMO

With the global trend toward an aging population, the increasing number of dementia patients and elderly living alone has emerged as a serious social issue in South Korea. The assessment of activities of daily living (ADL) is essential for diagnosing dementia. However, since the assessment is based on the ADL questionnaire, it relies on subjective judgment and lacks objectivity. Seven healthy seniors and six with early-stage dementia participated in the study to obtain ADL data. The derived ADL features were generated by smart home sensors. Statistical methods and machine learning techniques were employed to develop a model for auto-classifying the normal controls and early-stage dementia patients. The proposed approach verified the developed model as an objective ADL evaluation tool for the diagnosis of dementia. A random forest algorithm was used to compare a personalized model and a non-personalized model. The comparison result verified that the accuracy (91.20%) of the personalized model was higher than that (84.54%) of the non-personalized model. This indicates that the cognitive ability-based personalization showed encouraging performance in the classification of normal control and early-stage dementia and it is expected that the findings of this study will serve as important basic data for the objective diagnosis of dementia.


Assuntos
Atividades Cotidianas , Demência , Idoso , Envelhecimento , Cognição , Demência/diagnóstico , Demência/epidemiologia , Ambiente Domiciliar , Humanos
5.
ACS Nano ; 15(10): 16904-16912, 2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34661389

RESUMO

Ferromagnetism in two-dimensional materials presents a promising platform for the development of ultrathin spintronic devices with advanced functionalities. Recently discovered ferromagnetic van der Waals crystals such as CrI3, readily isolated two-dimensional crystals, are highly tunable through external fields or structural modifications. However, there remains a challenge because of material instability under air exposure. Here, we report the observation of an air-stable and layer-dependent ferromagnetic (FM) van der Waals crystal, CrPS4, using magneto-optic Kerr effect microscopy. In contrast to the antiferromagnetic (AFM) bulk, the FM out-of-plane spin orientation is found in the monolayer crystal. Furthermore, alternating AFM and FM properties observed in even and odd layers suggest robust antiferromagnetic exchange interactions between layers. The observed ferromagnetism in these crystals remains resilient even after the air exposure of about a day, providing possibilities for the practical applications of van der Waals spintronics.

6.
Nanoscale Res Lett ; 12(1): 373, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28549378

RESUMO

We report p-type tin monoselenide (SnSe) single crystals, grown in double-sealed quartz ampoules using a modified Bridgman technique at 920 °C. X-ray powder diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX) measurements clearly confirm that the grown SnSe consists of single-crystal SnSe. Electrical transport of multi-layer SnSe nanoflakes, which were prepared by exfoliation from bulk single crystals, was conducted using back-gated field-effect transistor (FET) structures with Au and Ti contacts on SiO2/Si substrates, revealing that multi-layer SnSe nanoflakes exhibit p-type semiconductor characteristics owing to the Sn vacancies on the surfaces of SnSe nanoflakes. In addition, a strong carrier screening effect was observed in 70-90-nm-thick SnSe nanoflake FETs. Furthermore, the effect of the metal contacts to multi-layer SnSe nanoflake-based FETs is also discussed with two different metals, such as Ti/Au and Au contacts.

7.
Nanoscale ; 9(21): 7027-7036, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28368061

RESUMO

Recently, significant progress has been made in increasing the figure-of-merit (ZT) of various nanostructured materials, including thin-film and quantum dot superlattice structures. Studies have focused on the size reduction and control of the surface or interface of nanostructured materials since these approaches enhance the thermopower and phonon scattering in quantum and superlattice structures. Currently, bismuth-tellurium-based semiconductor materials are widely employed for thermoelectric (TE) devices such as TE energy generators and coolers, in addition to other sensors, for use at temperatures under 400 K. However, new and promising TE materials with enhanced TE performance, including doped zinc oxide (ZnO) multilayer or superlattice thin films, are also required for designing solid-state TE power generating devices with the maximum output power density and for investigating the physics of in-plane TE generators. Herein, we report the growth of Al2O3/ZnO (AO/ZnO) superlattice thin films, which were prepared by atomic layer deposition (ALD), and the evaluation of their electrical and TE properties. All the in-plane TE properties, including the Seebeck coefficient (S), electrical conductivity (σ), and thermal conductivity (κ), of the AO/ZnO superlattice (with a 0.82 nm-thick AO layer) and AO/ZnO films (with a 0.13 nm-thick AO layer) were evaluated in the temperature range 40-300 K, and the measured S, σ, and κ were -62.4 and -17.5 µV K-1, 113 and 847 (Ω cm)-1, and 0.96 and 1.04 W m-1 K-1, respectively, at 300 K. Consequently, the in-plane TE ZT factor of AO/ZnO superlattice films was found to be ∼0.014, which is approximately two times more than that of AO/ZnO films (ZT of ∼0.007) at 300 K. Furthermore, the electrical power generation efficiency of the TE energy generator consisting of four couples of n-AO/ZnO superlattice films and p-Bi0.5Sb1.5Te3 (p-BST) thin-film legs on the substrate was demonstrated. Surprisingly, the output power of the 100 nm-thick n-AO/ZnO superlattice film/p-BST TE energy generator was determined to be ∼1.0 nW at a temperature difference of 80 K, corresponding to a significant improvement of ∼130% and ∼220% compared to the 100 nm-thick AO/ZnO film/p-BST and n-BT/p-BST film generators, respectively, owing to the enhancement of the TE properties, including the power factor of the superlattice film.

8.
Anat Cell Biol ; 46(3): 171-6, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24179691

RESUMO

This study aimed to measure the thickness of the epithelium and lamina propria of the palatal mucosa and to elucidate the location of the greater palatine artery to provide the anatomical basis for subepithelial connective tissue grafting. Thirty-two maxillary specimens, taken from the canine distal area to the first molar distal area, were embedded in paraffin and stained with hematoxylin-eosin. The thickness of the epithelium and lamina propria of the palatal mucosa was measured at three positions on these specimens, starting from 3 mm below the alveolar crest and in 3-mm intervals. The location of the greater palatine artery was evaluated by using image-processing software. The mean epithelial thickness decreased significantly in the posterior teeth; it was 0.41, 0.36, 0.32, and 0.30 mm in the canine, first premolar, second premolar, and first molar distal areas, respectively. The lamina propria was significantly thicker in the canine distal; it was 1.36, 1.08, 1.09, and 1.05 mm, respectively. The mean length from the alveolar crest to the greater palatine artery increased toward the posterior molar; it was 7.76, 9.21, 10.93, and 11.28 mm, respectively. The mean depth from the surface of the palatal mucosa to the greater palatine artery decreased from the canine distal to the first premolar distal but increased again toward the posterior molar; it was 3.97, 3.09, 3.58, and 5.50 mm, respectively. Detailed histological assessments of the lamina propria of the palatal mucosa and the greater palatine artery are expected to provide useful anatomical guidelines for subepithelial connective tissue grafting.

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