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1.
J Clin Monit Comput ; 2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-39158783

RESUMO

PURPOSE: Intraoperative hypotension is associated with adverse outcomes. Predicting and proactively managing hypotension can reduce its incidence. Previously, hypotension prediction algorithms using artificial intelligence were developed for invasive arterial blood pressure monitors. This study tested whether routine non-invasive monitors could also predict intraoperative hypotension using deep learning algorithms. METHODS: An open-source database of non-cardiac surgery patients ( https://vitadb.net/dataset ) was used to develop the deep learning algorithm. The algorithm was validated using external data obtained from a tertiary Korean hospital. Intraoperative hypotension was defined as a systolic blood pressure less than 90 mmHg. The input data included five monitors: non-invasive blood pressure, electrocardiography, photoplethysmography, capnography, and bispectral index. The primary outcome was the performance of the deep learning model as assessed by the area under the receiver operating characteristic curve (AUROC). RESULTS: Data from 4754 and 421 patients were used for algorithm development and external validation, respectively. The fully connected model of Multi-head Attention architecture and the Globally Attentive Locally Recurrent model with Focal Loss function were able to predict intraoperative hypotension 5 min before its occurrence. The AUROC of the algorithm was 0.917 (95% confidence interval [CI], 0.915-0.918) for the original data and 0.833 (95% CI, 0.830-0.836) for the external validation data. Attention map, which quantified the contributions of each monitor, showed that our algorithm utilized data from each monitor with weights ranging from 8 to 22% for determining hypotension. CONCLUSIONS: A deep learning model utilizing multi-channel non-invasive monitors could predict intraoperative hypotension with high accuracy. Future prospective studies are needed to determine whether this model can assist clinicians in preventing hypotension in patients undergoing surgery with non-invasive monitoring.

2.
J Nanobiotechnology ; 21(1): 310, 2023 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-37658367

RESUMO

BACKGROUND: Basic fibroblast growth factor (bFGF) is one of the critical components accelerating angiogenesis and tissue regeneration by promoting the migration of dermal fibroblasts and endothelial cells associated with matrix formation and remodeling in wound healing process. However, clinical applications of bFGF are substantially limited by its unstable nature due to rapid decomposition under physiological microenvironment. RESULTS: In this study, we present the bFGF-loaded human serum albumin nanoparticles (HSA-bFGF NPs) as a means of enhanced stability and sustained release platform during tissue regeneration. Spherical shape of the HSA-bFGF NPs with uniform size distribution (polydispersity index < 0.2) is obtained via a simple desolvation and crosslinking process. The HSA-bFGF NPs securely load and release the intact soluble bFGF proteins, thereby significantly enhancing the proliferation and migration activity of human dermal fibroblasts. Myofibroblast-related genes and proteins were also significantly down-regulated, indicating decrease in risk of scar formation. Furthermore, wound healing is accelerated while achieving a highly organized extracellular matrix and enhanced angiogenesis in vivo. CONCLUSION: Consequently, the HSA-bFGF NPs are suggested not only as a delivery vehicle but also as a protein stabilizer for effective wound healing and tissue regeneration.


Assuntos
Fator 2 de Crescimento de Fibroblastos , Nanopartículas , Humanos , Fator 2 de Crescimento de Fibroblastos/farmacologia , Células Endoteliais , Albumina Sérica Humana , Cicatrização
3.
Int J Mol Sci ; 23(20)2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36293347

RESUMO

Electrical signals represent an essential form of cellular communication. For decades, electrical stimulation has been used effectively in clinical practice to enhance bone healing. However, the detailed mechanisms between electrical stimulation and bone healing are not well understood. In addition, there have been many difficulties in setting up a stable and efficient electrical stimulation system within the in vitro environment. Therefore, various conductive materials and electrical stimulation methods have been tested to establish an effective electrical stimulation system. Through these systems, many studies have been conducted on the effects of electrical stimulation on bone healing and osteogenic differentiation. However, previous studies were limited by the use of opaque conductive materials that obscure the cells; fluorescent observations and staining are known to be two of the critical methods to confirm the states of the cells. Indium tin oxide (ITO) glass is known to have excellent transparency and conductivity, but it is challenging to cultivate cells due to low cell adhesion characteristics. Therefore, we used O2 plasma treatment to increase the hydrophilicity and wettability of ITO glass. This enhanced cell affinity to the glass, providing a stable surface for the cells to attach. Then, electrical stimulation was applied with an amplitude range of 10 to 200 µA at a frequency of 10 Hz. Our results demonstrated that the osteogenic differentiation efficiency was maximized under the amplitude conditions of 10 µA and 50 µA. Accordingly, the results of our study suggest the development of an excellent platform in the field of biological research as a good tool to elucidate various mechanisms of cell bioactivity under electrical conditions.


Assuntos
Células-Tronco Mesenquimais , Osteogênese , Humanos , Diferenciação Celular , Estimulação Elétrica
4.
Odontology ; 109(2): 411-421, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32980911

RESUMO

This retrospective study investigated the effect of mineral trioxide aggregate (MTA) plug location on treatment outcome and root maturation after regenerative endodontic procedures (REP) in immature permanent teeth. Thirty-three roots (n = 33) in cohort that underwent REP consistently according to AAE guideline were included to trace radiographic changes for the root and canal dimensions. Based on intraoral radiographs, roots were divided into two groups depending on the location of MTA plug within whole root length: coronal group (n = 14), within the upper half; apical group (n = 19), within the lower half. Periapical radiographs were standardized to assess treatment outcomes and root maturation including root development stages and digital measurements on the change ratios of root length, apex width, radiographic root area (RRA), modified RRA (mRRA), and periapical rarefaction area. The data were statistically analysed using the Mann-Whitney test. The patients' average age was 11 years and 10 months, with no significant between-group difference in sex. Premolars were the most prevalent tooth type (62.1%), followed by incisiors and molars. Pre-existing symptoms and signs subsided within 6 months in all cases. The teeth showed similar radiographic root development in both groups (P > 0.05). However, mRRA increase ratio was significantly higher in apical group than that in coronal group at early (< 6 months) and late (< 24 months) periods of follow-up (P < 0.05). Significant changes of root development stage were observed at early period for apical group and at late period for coronal group (P < 0.05). All the observed cases showed continuing root development after REP. Significant changes in root developments occurred at different follow-up periods according to the location of MTA plugs.


Assuntos
Endodontia Regenerativa , Materiais Restauradores do Canal Radicular , Compostos de Alumínio , Compostos de Cálcio , Criança , Combinação de Medicamentos , Humanos , Óxidos , Estudos Retrospectivos , Silicatos , Ápice Dentário/diagnóstico por imagem
5.
Eur J Dent Educ ; 25(1): 78-85, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32777126

RESUMO

INTRODUCTION: Accurate clinical decision-making of dentists should be based on their knowledge and experience. In the past 10 years, interest in competency-based dentistry education has rapidly increased, but there has been little attention paid to methods of improving dental education competency. The purpose of this study was to develop a clinical presentation education model that provides opportunities for students to practice problem-solving from the moment they greet the patient so that students can obtain the practical experience of competency-based education and the effectiveness of this model can be confirmed through pilot test. METHODS: This article is divided two parts: First, developing the clinical presentation dental education model (CPDEM) and Second, a pilot study adopted CPDEM. To confirm the effectiveness of this model, the students' satisfaction, their perception of self-achievement were analysed. RESULTS: Clinical presentation dental education model has been developed to provide practice-related education experience and provide linkage between basic science and clinical science. The result of applying this education model to 10 students as a pilot test was shown an overall high satisfaction level. In addition, self-achievement students' reported of all intended competencies was higher than for non-participating students of this model. CONCLUSIONS: This study focuses on practical education centring on clinical presentation. This model could get a meaningful and realistic experiences through the practice using clinical presentation of patients, use their metacognition for organizing and memorizing the patient's case by using concept map. It can be used as a future instructional method to enhance students' competency.


Assuntos
Currículo , Educação em Odontologia , Competência Clínica , Humanos , Modelos Educacionais , Projetos Piloto
6.
J Appl Biomech ; 37(6): 619-628, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34872077

RESUMO

The purpose of this study was to investigate the linear relationships among the hand/clubhead motion characteristics in golf driving in skilled male golfers (n = 66; handicap ≤ 3). The hand motion plane (HMP) and functional swing plane (FSP) angles, the HMP-FSP angle gaps, the planarity characteristics of the off-plane motion of the clubhead, and the attack angles were computed from the drives captured by an optical motion capture system. The HMP angles were identified as the key variables, as the HMP and FSP angles were intercorrelated, but the plane angle gaps, the planarity bias, and the attack angles showed correlations to the HMP angles primarily. Three main swing pattern clusters were identified. The parallel HMP-FSP alignment pattern with a small direction gap was associated with neutral planarity and planar swing pattern. The inward alignment pattern with a large inward direction gap was characterized by flat planes, follow-through-centric planarity, spiral swing pattern, and inward/downward impact. The outward alignment pattern with a large outward direction gap was associated with steep planes, downswing-centric planarity, reverse spiral swing, and outward/upward impact. The findings suggest that practical drills targeting the hand motion pattern can be effective in holistically reprogramming the swing pattern.


Assuntos
Golfe , Fenômenos Biomecânicos , Mãos , Humanos , Masculino , Amplitude de Movimento Articular , Extremidade Superior
7.
Nanotechnology ; 31(12): 125301, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-31783377

RESUMO

Recently, coloring based on nanostructure-light interaction has attracted much attention, because it has many advantages over pigment-based conventional coloring in terms of being non-toxic and highly durable in the environment, and providing high resolution. The asymmetric Fabry-Perot (FP) cavity absorber is the most manufacturable structure among coloring structures because it is simply produced and easily tunable. However, it cannot be applied practically because of the lack of a manufacturing technique that enables simultaneous fabrication of multi-color structures with different heights. Here, the fabrication of colored reflective characters based on various asymmetric FP absorbers with micrometer-scale pixel size are reported. Various cavities with different thicknesses are fabricated in a single step using UV imprint lithography and a simple deposition process. UV/visible spectroscopy is used to characterize the fabricated FP resonator. This absorber demonstrates high absorption, close to 90%, resulting in vivid colors with high resolution of 12700 DPI. It can be potentially used in reflective color displays field, functionalized color decorations, and security color patterns area. It is believed that this study would open up new possibilities for high density color printing in practical industry by introducing cost effective nanoimprint lithography technology.

8.
Nanotechnology ; 31(14): 144003, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-31891918

RESUMO

A phosphor substrate converts a moderate amount of blue light to green light to produce white light. In this study, we have successfully demonstrated the enhancement of the light extraction efficiency of YAG:Ce phosphor substrate using a simple imprint process. Spin-on-glass materials were used to fabricate a pattern on the surface of a phosphor substrate, and nano- and micro-scale patterns were formed to test the performance according to the size of pattern. The light extraction efficiency of the phosphor substrate with a micro-cone pattern increased by 33.2% compared with the flat phosphor substrate.

9.
Clin Oral Investig ; 24(11): 3863-3870, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32170546

RESUMO

OBJECTIVES: To obtain radicular measurements of two separate mesiobuccal (MB) root canals in maxillary first molars using micro-computed tomography (µCT) with customized software. MATERIALS AND METHODS: Human maxillary first molar MB roots (N = 36) with two separate canals (MB1, MB2) and apical foramina were scanned by µCT and analyzed with Kappa2 software to reconstruct three-dimensional (3D) surface models of roots and canals. These models were sectioned at 0.1 mm intervals perpendicular to the central axis of each canal. Canal widths, 3D curvatures, and surrounding dentine thicknesses were measured concurrently on each section. Dentine thicknesses were analyzed statistically for differences between each direction and the different levels of both canals. RESULTS: Dentine walls around MB1 were thicker than MB2 (p < 0.05). Thinnest dentine was most often located at disto-inside direction in both canals. Canal widths were significantly smaller in MB2 than MB1 (p < 0.01). Apical constrictions were smaller (p < 0.05) and further (p < 0.05) from the apex in MB2 than MB1. Canal curvatures were greatest in the apical third of both canals (p < 0.001), and they were greater in MB2 than MB1 (p < 0.05). CONCLUSIONS: MB2 canals had shorter lengths, smaller widths, and more severe curvatures and were surrounded by thinner dentine walls. In MB2, apical constrictions were between 1 and 2 mm from the apex, compared to about 1 mm for MB1. CLINICAL RELEVANCE: These detailed measurements and in-depth 3D analyses of maxillary first molar MB roots with two separate canals and apical foramina provide morphologic references for root canal therapy.


Assuntos
Cavidade Pulpar , Maxila , Cavidade Pulpar/diagnóstico por imagem , Humanos , Maxila/diagnóstico por imagem , Dente Molar/diagnóstico por imagem , Raiz Dentária/diagnóstico por imagem , Microtomografia por Raio-X
10.
Financ Res Lett ; 37: 101748, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32895607

RESUMO

COVID-19 has had significant impact on US stock market volatility. This study focuses on understanding the regime change from lower to higher volatility identified with a Markov Switching AR model. Utilizing machine learning feature selection methods, economic indicators are chosen to best explain changes in volatility. Results show that volatility is affected by specific economic indicators and is sensitive to COVID-19 news. Both negative and positive COVID-19 information is significant, though negative news is more impactful, suggesting a negativity bias. Significant increases in total and idiosyncratic risk are observed across all industries, while changes in systematic risk vary across industry.

11.
Int J Mol Sci ; 21(1)2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31861863

RESUMO

Human ß defensin-3-C15, an epithelium-derived cationic peptide that has antibacterial/antifungal and immuno-regulatory properties, is getting attention as potential therapeutic agent in endodontics. This study aimed to investigate if synthetic human ß defensin-3-C15 (HBD3-C15) peptides could inhibit inflammatory responses in human dental pulp cells (hDPCs), which had been induced by gram-positive endodontic pathogen. hDPC explant cultures were stimulated with Streptococcus gordonii lipoprotein extracts for 24 h to induce expression of pro-inflammatory mediators. The cells were then treated with either HBD3-C15 (50 µg/mL) or calcium hydroxide (CH, 100 µg/mL) as control for seven days, to assess their anti-inflammatory effects. Quantitative RT-PCR analyses and multiplex assays showed that S. gordonii lipoprotein induced the inflammatory reaction in hDPCs. There was a significant reduction of IL-8 and MCP-1 within 24 h of treatment with either CH or HBD3-C15 (p < 0.05), which was sustained over 1 week of treatment. Alleviation of inflammation in both medications was related to COX-2 expression and PGE2 secretion (p < 0.05), rather than TLR2 changes (p > 0.05). These findings demonstrate comparable effects of CH and HDB3-C15 as therapeutic agents for inflamed hDPCs.


Assuntos
Anti-Inflamatórios/farmacologia , Lipoproteínas/imunologia , Infecções Estreptocócicas/imunologia , Streptococcus gordonii/imunologia , beta-Defensinas/farmacologia , Anti-Inflamatórios/síntese química , Células Cultivadas , Polpa Dentária/citologia , Polpa Dentária/efeitos dos fármacos , Polpa Dentária/imunologia , Humanos , Inflamação/tratamento farmacológico , Inflamação/etiologia , Inflamação/imunologia , Modelos Moleculares , Infecções Estreptocócicas/complicações , Infecções Estreptocócicas/tratamento farmacológico , beta-Defensinas/síntese química
12.
BMC Oral Health ; 17(1): 110, 2017 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-28697771

RESUMO

BACKGROUND: Although many studies have compared the properties of ultrasonic scaling instruments, it remains controversial as to which is most suitable for implant scaling. This study evaluated the safety and efficiency of novel metallic ultrasonic scaler tips made by the powder injection molding (PIM) technique on titanium surfaces. METHODS: Mechanical instrumentation was carried out using four types of metal scaler tips consisting of copper (CU), bronze (BR), 316 L stainless steel (316 L), and conventional stainless steel (SS) tips. The instrumented surface alteration image of samples was viewed with scanning electron microscope (SEM) and surface profile of the each sample was investigated with confocal laser scanning microscopy (CLSM). Arithmetic mean roughness (Ra) and maximum height roughness (Rmax) of titanium samples were measured and dissipated power of the scaler tip was estimated for scaling efficiency. RESULTS: The average Ra values caused by the 316 L and SS tip were about two times higher than those of the CU and BR tips (p < 0.05). The Rmax value showed similar results. The efficiency of the SS tip was about 3 times higher than that of CU tip, the 316 L tip is about 2.7 times higher than that of CU tip, and the BR tip is about 1.2 times higher than that of CU tip. CONCLUSIONS: Novel metallic bronze alloy ultrasonic scaler tip minimally damages titanium surfaces, similar to copper alloy tip. Therefore, this bronze alloy scaler tip may be promising instrument for implant maintenance therapy.


Assuntos
Implantes Dentários , Planejamento de Prótese Dentária/métodos , Planejamento de Prótese Dentária/instrumentação , Humanos , Microscopia Confocal , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Titânio , Ultrassom
13.
Appl Microbiol Biotechnol ; 100(6): 2737-48, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26596574

RESUMO

There is an increasing demand for microbial production of lactic acid (LA) as a monomer of biodegradable poly lactic acid (PLA). Both optical isomers, D-LA and L-LA, are required to produce stereocomplex PLA with improved properties. In this study, we developed Saccharomyces cerevisiae strains for efficient production of D-LA. D-LA production was achieved by expressing highly stereospecific D-lactate dehydrogenase gene (ldhA, LEUM_1756) from Leuconostoc mesenteroides subsp. mesenteroides ATCC 8293 in S. cerevisiae lacking natural LA production activity. D-LA consumption after glucose depletion was inhibited by deleting DLD1 encoding D-lactate dehydrogenase and JEN1 encoding monocarboxylate transporter. In addition, ethanol production was reduced by deleting PDC1 and ADH1 genes encoding major pyruvate decarboxylase and alcohol dehydrogenase, respectively, and glycerol production was eliminated by deleting GPD1 and GPD2 genes encoding glycerol-3-phosphate dehydrogenase. LA tolerance of the engineered D-LA-producing strain was enhanced by adaptive evolution and overexpression of HAA1 encoding a transcriptional activator involved in weak acid stress response, resulting in effective D-LA production up to 48.9 g/L without neutralization. In a flask fed-batch fermentation under neutralizing condition, our evolved strain produced 112.0 g/L D-LA with a yield of 0.80 g/g glucose and a productivity of 2.2 g/(L · h).


Assuntos
Ácido Láctico/metabolismo , Engenharia Metabólica/métodos , Redes e Vias Metabólicas/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Adaptação Biológica , Deleção de Genes , Expressão Gênica , Leuconostoc/enzimologia , Leuconostoc/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Saccharomyces cerevisiae/crescimento & desenvolvimento
14.
Mediators Inflamm ; 2015: 385127, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26604431

RESUMO

Porphyromonas gingivalis is considered with inducing pulpal inflammation and has lipopolysaccharide (LPS) as an inflammatory stimulator. GV1001 peptide has anticancer and anti-inflammation activity due to inhibiting activation of signaling molecules after penetration into the various types of cells. Therefore, this study examined inhibitory effect of GV1001 on dental pulp cells (hDPCs) stimulated by P. gingivalis LPS. The intracellular distribution of GV1001 was analyzed by confocal microscopy. Real-time RT-PCR was performed to determine the expression levels of TNF-α and IL-6 cytokines. The role of signaling by MAP kinases (ERK and p38) was explored using Western blot analysis. The effect of GV1001 peptide on hDPCs viability was measured by MTT assay. GV1001 was predominantly located in hDPC cytoplasm. The peptide inhibited P. gingivalis LPS-induced TNF-α and IL-6 production in hDPCs without significant cytotoxicity. Furthermore, GV1001 treatment markedly inhibited the phosphorylation of MAP kinases (ERK and p38) in LPS-stimulated hDPCs. GV1001 may prevent P. gingivalis LPS-induced inflammation of apical tissue. Also, these findings provide mechanistic insight into how GV1001 peptide causes anti-inflammatory actions in LPS-stimulated pulpitis without significantly affecting cell viability.


Assuntos
Anti-Inflamatórios/farmacologia , Citocinas/biossíntese , Polpa Dentária/imunologia , Lipopolissacarídeos/farmacologia , Fragmentos de Peptídeos/farmacologia , Porphyromonas gingivalis/patogenicidade , Telomerase/farmacologia , Adolescente , Adulto , Polpa Dentária/citologia , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Humanos , Interleucina-6/biossíntese , Telomerase/metabolismo , Receptores Toll-Like/fisiologia , Fator de Necrose Tumoral alfa/biossíntese , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidores
15.
Acta Odontol Scand ; 73(6): 427-32, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25385684

RESUMO

OBJECTIVE: Micro-computed tomography (MCT) with alternative image reformatting techniques shows complex and detailed root canal anatomy. This study compared two-dimensional (2D) and 3D MCT image reformatting with standard tooth clearing for studying mandibular first molar mesial root canal morphology. MATERIALS AND METHODS: Extracted human mandibular first molar mesial roots (n=31) were scanned by MCT (Skyscan 1172). 2D thin-slab minimum intensity projection (TS-MinIP) and 3D volume rendered images were constructed. The same teeth were then processed by clearing and staining. For each root, images obtained from clearing, 2D, 3D and combined 2D and 3D techniques were examined independently by four endodontists and categorized according to Vertucci's classification. Fine anatomical structures such as accessory canals, intercanal communications and loops were also identified. RESULTS: Agreement among the four techniques for Vertucci's classification was 45.2% (14/31). The most frequent were Vertucci's type IV and then type II, although many had complex configurations that were non-classifiable. Generally, complex canal systems were more clearly visible in MCT images than with standard clearing and staining. Fine anatomical structures such as intercanal communications, accessory canals and loops were mostly detected with a combination of 2D TS-MinIP and 3D volume-rendering MCT images. CONCLUSIONS: Canal configurations and fine anatomic structures were more clearly observed in the combined 2D and 3D MCT images than the clearing technique. The frequency of non-classifiable configurations demonstrated the complexity of mandibular first molar mesial root canal anatomy.


Assuntos
Cavidade Pulpar/diagnóstico por imagem , Dente Molar/diagnóstico por imagem , Preparo de Canal Radicular/métodos , Microtomografia por Raio-X/métodos , Adulto , Anatomia Transversal/métodos , Corantes , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Pessoa de Meia-Idade , Raiz Dentária/diagnóstico por imagem
16.
J Dent Sci ; 19(2): 909-918, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38618054

RESUMO

Background/purpose: The COVID-19 pandemic has had a profound and enduring impact on various aspects of society, including medical education and the training of dental students. The field of dentistry, given its nature, is particularly susceptible to the challenges posed by a pandemic. Prolonged exposure to the pandemic is believed to have increased stress and burnout among medical and dental students. This study aimed to investigate and analyze the relationship between COVID-19 and stress, burnout, and depression in Korean dental students. Materials and methods: A cross-sectional survey was conducted among 162 third and fourth-grade students from the School of Dentistry at Seoul National University. The survey comprised four main sections: general information, the Maslach Burnout Inventory (MBI), the Patient Health Questionnaire-9 (PHQ-9), and the Impact of Event Scale-Revised (IES-R). Results: The results indicated significant differences in age, study time, career satisfaction, and counseling needs between third and fourth-grade students. The fourth-grade students exhibited higher scores in the IES-R survey, PHQ-9 total score, emotional exhaustion, and depersonalization subscale items of the MBI. Furthermore, the group with abnormal responses to COVID-19 demonstrated lower levels of career satisfaction. Conclusion: Fourth-grade dental students experienced higher levels of depression, vulnerability to the effects of COVID-19, and burnout. These findings highlight the need for addressing the mental health challenges faced by dental students during the COVID-19 pandemic.

17.
Sports Biomech ; : 1-15, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38623642

RESUMO

Vertical and horizontal rhythms are crucial aspects of a dynamic golf swing, and the two-step swing drills (TSSD) were specifically designed to promote rhythmic unloading and loading of the legs. The purpose of this study was to evaluate the effects of a TSSD training session on the swing rhythm and clubhead speed (CHS) among competitive junior golfers (3.1 ± 4.4 hcp). The driver swings (7 swings each) of 10 competitive junior golfers (aged 15-18) were captured before and after a TSSD session consisting of four stages (lasting less than 45 minutes). Post-TSSD training, there were significant increases in CHS (p < .001), maximum unweighting (p = .006), the trail-side push (p = .009), the horizontal motion ranges of the body and pelvis (p = .005-.031), the upward/downward motion range of the body in the backswing (p = .042/.024), and the backswing/downswing angular velocity peaks of the axle-chain system (p < .033). The stepping-like leg actions primarily facilitated horizontal motion rhythm over vertical motion and unweighting over push in terms of ground interaction. These findings suggest that TSSD can serve as an effective method for developing a rhythmic and dynamic motion pattern while increasing CHS.

18.
Biomater Res ; 28: 0011, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38500782

RESUMO

Background: To improve the efficiency of neural development from human embryonic stem cells, human embryoid body (hEB) generation is vital through 3-dimensional formation. However, conventional approaches still have limitations: long-term cultivation and laborious steps for lineage determination. Methods: In this study, we controlled the size of hEBs for ectodermal lineage specification using cell-penetrating magnetic nanoparticles (MNPs), which resulted in reduced time required for initial neural induction. The magnetized cells were applied to concentrated magnetic force for magnet-derived multicellular organization. The uniformly sized hEBs were differentiated in neural induction medium (NIM) and suspended condition. This neurally induced MNP-hEBs were compared with other groups. Results: As a result, the uniformly sized MNP-hEBs in NIM showed significantly improved neural inductivity through morphological analysis and expression of neural markers. Signaling pathways of the accelerated neural induction were detected via expression of representative proteins; Wnt signaling, dopaminergic neuronal pathway, intercellular communications, and mechanotransduction. Consequently, we could shorten the time necessary for early neurogenesis, thereby enhancing the neural induction efficiency. Conclusion: Overall, this study suggests not only the importance of size regulation of hEBs at initial differentiation stage but also the efficacy of MNP-based neural induction method and stimulations for enhanced neural tissue regeneration.

19.
Microb Cell Fact ; 12: 14, 2013 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-23383678

RESUMO

BACKGROUND: Cellulosic biomass is considered as a promising alternative to fossil fuels, but its recalcitrant nature and high cost of cellulase are the major obstacles to utilize this material. Consolidated bioprocessing (CBP), combining cellulase production, saccharification, and fermentation into one step, has been proposed as the most efficient way to reduce the production cost of cellulosic bioethanol. In this study, we developed a cellulolytic yeast consortium for CBP, based on the surface display of cellulosome structure, mimicking the cellulolytic bacterium, Clostridium thermocellum. RESULTS: We designed a cellulolytic yeast consortium composed of four different yeast strains capable of either displaying a scaffoldin (mini CipA) containing three cohesin domains derived from C. thermocellum, or secreting one of the three types of cellulases, C. thermocellum CelA (endoglucanase) containing its own dockerin, Trichoderma reesei CBHII (exoglucanase) fused with an exogenous dockerin from C. thermocellum, or Aspergillus aculeatus BGLI (ß-glucosidase). The secreted dockerin-containing enzymes, CelA and CBHI, were randomly assembled to the surface-displayed mini CipA via cohesin-dockerin interactions. On the other hand, BGLI was independently assembled to the cell surface since we newly found that it already has a cell adhesion characteristic. We optimized the cellulosome activity and ethanol production by controlling the combination ratio among the four yeast strains. A mixture of cells with the optimized mini CipA:CelA:CBHII:BGLI ratio of 2:3:3:0.53 produced 1.80 g/l ethanol after 94 h, indicating about 20% increase compared with a consortium composed of an equal amount of each cell type (1.48 g/l). CONCLUSIONS: We produced cellulosic ethanol using a cellulolytic yeast consortium, which is composed of cells displaying mini cellulosomes generated via random assembly of CelA and CBHII to a mini CipA, and cells displaying BGLI independently. One of the advantages of this system is that ethanol production can be easily optimized by simply changing the combination ratio of the different populations. In addition, there is no limitation on the number of enzymes to be incorporated into this cellulosome structure. Not only cellulases used in this study, but also any other enzymes, including cellulases and hemicellulases, could be applied just by fusing dockerin domains to the enzymes.


Assuntos
Celulose/metabolismo , Celulossomas/metabolismo , Clostridium thermocellum/metabolismo , Etanol/metabolismo , beta-Glucosidase/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Biomassa , Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Celulase/química , Celulase/metabolismo , Celulose 1,4-beta-Celobiosidase/química , Celulose 1,4-beta-Celobiosidase/metabolismo , Clostridium thermocellum/enzimologia , Estrutura Terciária de Proteína , Trichoderma/enzimologia , beta-Glucosidase/química
20.
Biomedicines ; 11(10)2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37893084

RESUMO

Gastric cancer remains a global health threat, particularly in Asian countries. Current treatment methods include surgery, chemotherapy, and radiation therapy. However, they all have limitations, such as adverse side effects, tumor resistance, and patient tolerance. Hyperthermia therapy uses heat to selectively target and destroy cancer cells, but it has limited efficacy when used alone. Linderae Radix (LR), a natural compound with thermogenic effects, has the potential to enhance the therapeutic efficacy of hyperthermia treatment. In this study, we investigated the synergistic anticancer effects of cotreatment with LR and 43 °C hyperthermia in AGS gastric cancer cells. The cotreatment inhibited AGS cell proliferation, induced apoptosis, caused cell cycle arrest, suppressed heat-induced heat shock responses, increased reactive oxygen species (ROS) generation, and promoted mitogen-activated protein kinase phosphorylation. N-acetylcysteine pretreatment abolished the apoptotic effect of LR and hyperthermia cotreatment, indicating the crucial role of ROS in mediating the observed anticancer effects. These findings highlight the potential of LR as an adjuvant to hyperthermia therapy for gastric cancer. Further research is needed to validate these findings in vivo, explore the underlying molecular pathways, and optimize treatment protocols for the development of novel and effective therapeutic strategies for patients with gastric cancer.

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