Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Heliyon ; 10(11): e32161, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38947488

RESUMO

Additive manufacturing (AM) has gained significant attention in recent years owing to its ability to fabricate intricate shapes and structures that are often challenging or unattainable using conventional manufacturing techniques. This high-quality development trend entails higher requirements for the structural design of 3D printers. In this study, polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS) filaments were fed through a heated extrusion nozzle, which melted the material and deposited it onto a build platform. This study's objectives are high-gravitational material extrusion (HG-MEX) systems development, analyzing the high gravity influences on the flow behavior of materials during extrusion, and understanding the effects of gravitational on material flow and overall extrusion performance. HG-MEX systems have great potential for addressing various challenges in additive manufacturing, such as precise manufacturing. The highlight of the progress is that we developed an HG-MEX system and applied surface science to material extrusion in different gravity. We established a system and obtained results on different gravity, we analyzed the analogy between different gravity phenomena. We analyzed the interplay between the behavior of the fabricated parts and gravity. We analyzed high gravity effects on extrusion processes. The results confirmed the characteristics and feasibility of the developed system. The results suggest that a material extrusion line operating under 15 G conditions resulted in better printing quality compared to one operating under 1 G conditions. This observation implies that high gravity had a positive effect on the extrusion process, leading to improved material extrusion performance.

2.
Sci Rep ; 13(1): 14224, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37648752

RESUMO

Additive manufacturing (AM) has gained significant attention in recent years owing to its ability to quickly and easily fabricate complex shapes and geometries that are difficult or impossible to achieve with traditional manufacturing methods. This study presents the development of a high-gravity material extrusion (HG-MEX) system, which generates a high-gravity field through centrifugal acceleration. In this process, the material is dissolved by heating the nozzle and subsequently deposited on the construction platform. The primary objective of this research is to evaluate the positive effects of gravity on material extrusion (MEX), which is a key aspect of AM. To accomplish this, a combined machine comprising a MEX unit and centrifuge is constructed. This HG-MEX system is used to analyze and reflect the influence of gravity on the material extrusion. The experimental evaluations demonstrate that the application of high gravity is a promising approach to improve the shape accuracy and performance of the parts fabricated through MEX. Notably, our results confirm the feasibility of utilizing MEX under high gravity to enhance performance in AM processes.

3.
Int J Clin Oncol ; 28(10): 1421-1430, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37584872

RESUMO

OBJECTIVE: Optimal adjuvant chemotherapy for nonsquamous cervical carcinoma has not yet been established. This study investigated the efficacy and safety of docetaxel/carboplatin (DC) for early-stage nonsquamous cell cervical carcinoma after radical hysterectomy (RH). METHODS: We evaluated 157 patients with stage IB-IIB nonsquamous cervical carcinoma with intermediate risk and high risk treated at our institution with DC after type II or III RH from 2007 to 2021. Patients received docetaxel (60-70 mg/m2) and carboplatin (area under the curve 5-6) every 3 weeks for six cycles. The primary endpoint was 2 year recurrence-free survival (RFS) and the secondary endpoint was adverse events (AEs). RESULTS: There were 106 intermediate-risk and 51 high-risk patients. The high-risk patients included 11 with positive parametrial involvement, 20 with pelvic lymph node metastases, and 20 with both parametrial involvement and pelvic lymph node metastases. The 2 year RFS rates for intermediate-risk, high-risk, and positive pelvic lymph nodes were 94.8% (95% confidence interval [CI], 87.9-97.8), 80.1% (95% CI, 64.1-89.5), and 74.5% (95% CI, 55.4-86.4), respectively. Sixteen patients had recurrence, including local recurrence (n = 6), distant metastasis (n = 9), and local and distant metastasis (n = 1). Hematologic toxicity was the most frequent AE, especially leukopenia and neutropenia. Nausea and constipation were the most frequent nonhematologic toxicities. CONCLUSION: DC therapy at our institution showed good 2 year RFS, and postoperative adjuvant therapy with DC therapy is suggested as a useful strategy for patients with nonsquamous cervical carcinoma.


Assuntos
Carcinoma , Neoplasias do Colo do Útero , Feminino , Humanos , Carboplatina , Estudos Retrospectivos , Docetaxel/uso terapêutico , Colo do Útero/patologia , Metástase Linfática , Quimioterapia Adjuvante , Carcinoma/tratamento farmacológico , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/cirurgia , Neoplasias do Colo do Útero/patologia , Histerectomia , Estadiamento de Neoplasias , Taxa de Sobrevida
4.
Polymers (Basel) ; 15(14)2023 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-37514426

RESUMO

Polymer science plays a crucial role in the understanding and numerical study of material extrusion processes that have revolutionized additive manufacturing (AM). This study investigated the impact of high-gravity conditions on material extrusion and conducted a numerical study by referring to the development of a high-gravity material extrusion system (HG-MEX). In this study, we evaluated the polymeric characteristics of HG-MEX. By analyzing the interplay between polymer behavior and gravity, we provide insights into the effects of high gravity on extrusion processes, including filament flow, material deposition, and the resulting fabrication characteristics. The established numerical study of high-gravity material extrusion in additive manufacturing is a meaningful and valuable approach for improving the quality and efficiency of the process. This study is unique in that it incorporates material surface characteristics to represent the performance and contact with polymer science in additive manufacturing. The findings presented herein contribute to a broader understanding of polymer science and its practical implications for HG-MEX under various gravitational conditions.

5.
Molecules ; 25(17)2020 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-32847022

RESUMO

Fusobacterium nucleatum (Fn) is generally an opportunistic oral pathogen that adheres to mammalian mucosal sites, triggering a host inflammatory response. In general, Fn is normally found within the human oral cavity; however, it was previously reported that Fn is a risk factor for certain respiratory diseases. Surprisingly, this was never fully elucidated. Here, we investigated the virulence potential of heat-killed Fn on primary human tracheal, bronchial, and alveolar epithelial cells. In this study, we measured the secretion of inflammatory- (IL-8 and IL-6), stress- (total heme and hydrogen peroxide), and cell death-related (caspase-1 and caspase-3) signals. We established that the inflammatory response mechanism varies in each epithelial cell type: (1) along tracheal cells, possible Fn adherence would trigger increased heme secretion and regulated inflammatory response; (2) along bronchial cells, potential Fn adherence would simultaneously initiate an increase in secreted H2O2 and inflammatory response (ascribable to decreased secreted heme amounts); and (3) along alveolar cells, putative Fn adherence would instigate the increased secretion of inflammatory responses attributable to a decrease in secreted heme levels. Moreover, regardless of the epithelial cell-specific inflammatory mechanism, we believe these are putative, not harmful. Taken together, we propose that any potential Fn-driven inflammation along the respiratory tract would be initiated by differing epithelial cell-specific inflammatory mechanisms that are collectively dependent on secreted heme.


Assuntos
Células Epiteliais Alveolares/metabolismo , Fusobacterium nucleatum/química , Heme/metabolismo , Temperatura Alta , Células Epiteliais Alveolares/patologia , Caspase 1/metabolismo , Caspase 3/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Inflamação/induzido quimicamente , Inflamação/metabolismo , Interleucina-6/metabolismo , Interleucina-8/metabolismo
6.
In Vivo ; 34(2): 587-594, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32111757

RESUMO

BACKGROUND/AIM: Epstein-Barr virus (EBV) associates with human chronic periodontitis (CP) progression. We previously demonstrated that butyric acid (BA), produced by periodontopathic bacteria, induced EBV lytic switch activator BZLF1 expression. We investigated whether short chain fatty acids (SCFAs) in CP patients' saliva enabled EBV reactivation. MATERIALS AND METHODS: Saliva was collected from seven CP patients and five periodontally healthy individuals. SCFAs were quantified using HPLC. BZLF1 mRNA and its pertinent protein ZEBRA were determined with Real-time PCR and western blotting. Histone H3 acetylation (AcH3) was further examined. RESULTS: BZLF1 mRNA expression and transcriptional activity in EBV-infected Daudi cells were induced only when treated with the CP saliva. Among SCFAs, BA alone correlated significantly with the BZLF1 transcription (r=0.88; p<0.02). As expected, CP patients' saliva induced AcH3. CONCLUSION: BA in saliva may play a role in EBV reactivation and hence contribute to EBV-related disease progression in CP patients.


Assuntos
Ácido Butírico/metabolismo , Periodontite Crônica/etiologia , Periodontite Crônica/metabolismo , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/virologia , Herpesvirus Humano 4/genética , Saliva/metabolismo , Transativadores/genética , Acetilação , Adulto , Idoso , Periodontite Crônica/patologia , Regulação Viral da Expressão Gênica , Histonas/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Pessoa de Meia-Idade , Projetos Piloto
7.
In Vivo ; 33(6): 1793-1800, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31662504

RESUMO

BACKGROUND/AIM: Human chronic periodontitis is a major health problem. Although some oral bacteria have been reported to be putative pathogens, Epstein-Barr virus (EBV) is reported to be associated with the progression of periodontitis. However, the role of EBV in the aetiology of periodontitis is unknown. Therefore, we investigated periodontal pathogenesis of EBV to confirm whether EBV-encoded latent membrane protein 1 (LMP1) induces Interleukin-8 (IL8) production in human gingival cells. MATERIALS AND METHODS: Real-time polymerase chain reaction, luciferase assay, enzyme-linked immunosorbent assay (ELISA), and western blotting were performed for determining IL8 mRNA expression, nuclear factor kappa B (NF-ĸB) transcription, IL8 production, and the phosphorylation of NF-ĸB p65 and Inhibitor of kappa B alpha (IĸBα), respectively, in Ca9-22 human gingival epithelial cells. Two LMP1 mutants lacking C-terminal activating region (CATR) domains responsible for activating NF-ĸB were used. RESULTS: Extremely high IL8 production was induced by LMP1 in time- and dose-dependent manner, where simultaneous phosphorylation of NF-κB p65 and IĸBα and transcription of NF-ĸB were observed. On the contrary, IL8 production and NF-ĸB transcription were drastically inhibited by dominant negative mutant of IĸBα. Moreover, the LMP1 mutants failed to induce IL8 production. CONCLUSION: Our findings suggest that due to CATR domains, LMP1 contributes to the progression of periodontitis via IL8 production attributable to NF-ĸB activation.


Assuntos
Periodontite Crônica/metabolismo , Células Epiteliais/metabolismo , Epitélio/metabolismo , Gengiva/metabolismo , Herpesvirus Humano 4/metabolismo , Interleucina-8/metabolismo , Proteínas da Matriz Viral/metabolismo , Linhagem Celular , Células Epiteliais/virologia , Epitélio/virologia , Gengiva/virologia , Humanos , NF-kappa B/metabolismo , Transdução de Sinais/fisiologia , Fator de Transcrição RelA/metabolismo
8.
Sci Rep ; 9(1): 13445, 2019 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-31530932

RESUMO

Epstein-Barr virus (EBV) is associated with several disorders. EBV is known to modulate the proliferation and survival of hematopoietic cells such as B cells and T cells in human. However, the effects of EBV on hematopoiesis itself have not been investigated. To study EBV infection in murine models, their hematopoiesis must be humanized, since EBV infection is limited only in primates. To engraft the human hematopoiesis, NOD/Shi-scid-IL2rγnull (NOG) mice were used. Usually, the hematopoiesis humanized mice reconstitute only lymphoid cells, but myeloid cells are not. However, we revealed human macrophages (hMφ) and their precursor monocytes were increased in peripheral tissues of EBV-infected mice. Furthermore, our previous report indicated Mφ accumulation in spleen was essential for development of EBV-positive tumors, suggesting that EBV modulates human hematopoiesis in order to thrive. Interestingly, we revealed a dramatic increase of immature granulocytes only in bone marrow of EBV-infected mice. In addition, GM-CSF, a cytokine that is essential for differentiation of the myeloid lineage, was significantly increased in EBV-infected mice. These results were also reproduced in patients with EBV-related disorders. We suggest that the hematopoietic alterations during EBV-infection might contribute immune suppression to the development and exacerbation of EBV-related disorders.


Assuntos
Medula Óssea/virologia , Infecções por Vírus Epstein-Barr/sangue , Animais , Medula Óssea/fisiologia , Infecções por Vírus Epstein-Barr/patologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/sangue , Hematopoese , Humanos , Leucócitos Mononucleares/virologia , Camundongos Endogâmicos NOD , Camundongos SCID
9.
Yakugaku Zasshi ; 137(12): 1543-1553, 2017 Dec 01.
Artigo em Japonês | MEDLINE | ID: mdl-28966222

RESUMO

1H quantitative NMR (1H qNMR) is known as a powerful tool for determination of analytes without the need for their identical standards, which is eligible to a primary rate method. 1H qNMR has been already stipulated to an assay for purity determination in Japanese Pharmacopoeia (JP), and then this technique has been also applied in several fields such as pharmaceutical and food sciences. However, there is little information about the accuracy of 1H qNMR so that the further applications into other fields such as industrial chemistry could be constricted. In this study, in order to assess the reliability of 1H qNMR, we designed the round-robin test of 1H qNMR under the basis of the measurement conditions described in JP. 1,4-Bis(trimethylsilyl)benzene-d4 [1,4-BTMSB-d4, 99.9±0.6% (w/w)] and 3,5-bis(trifluoromethyl)benzoic acid [3,5-BTMFBA, 99.96±0.06% (w/w)], which are certified reference materials (CRMs), were adopted to analyte and qNMR reference standard respectively for the accurate evaluation in this test. Six NMR instruments in 5 institutions optimized to 1H qNMR conditions provided the purity 1,4-BTMSB-d4 within acceptable error range. This result represented that 1H qNMR has the capability to determine precisely the value of analyte in practical analytical field and to be set as official analytical method for purity determination or assay of concentration of organic compounds.


Assuntos
Espectroscopia de Ressonância Magnética/normas , Deutério , Espectroscopia de Ressonância Magnética/instrumentação , Espectroscopia de Ressonância Magnética/métodos , Sensibilidade e Especificidade
10.
J Sep Sci ; 32(3): 399-407, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19142913

RESUMO

Separation methods based on capillary zone electrophoresis and micellar electrokinetic chromatography were developed to characterize the distribution of ethylene oxide (EO) homologues in the fatty alcohol ethoxylates (FAEs). Prior to the separation, the FAEs were derivatized with 2-fluoro-1-methylpyridinium p-toluenesulfonate (FMPTS) to allow CZE separation and UV detection. To prevent adsorption of cationic analytes onto the inner surface of the capillary and formation of micelles in CZE analysis, a lower pH background solution (BGS) containing a high concentration of acetonitrile was employed. Under optimal conditions, FMPTS-derivatized FAEs with an average EO number of 6 were completely separated within 11 min. For MEKC analysis of the FAEs, dodecyltrimethylammonium chloride (DTAC) was added to the BGS. In the presence of 30 mM DTAC in 10 mM phosphate buffer (pH 2.5) containing 20% (v/v) acetonitrile, superior oligomer separation of the FAEs containing up to 50 EO groups was achieved within 30 min with good analytical reproducibilities. Furthermore, the developed method was applied to the analysis of the FAEs in commercial products such as laundry detergent and fabric softener.

11.
J Sep Sci ; 31(5): 829-36, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18293423

RESUMO

The use of an inorganic layered compound as a pseudostationary phase (PSP) in EKC was investigated. A synthetic smectite, which is the most typical swellable clay mineral, with an average diameter of 130 nm was selected as the PSP. The retention characteristics of the smectite and on-line sample concentration by sweeping were examined for the analysis of polyoxyethylene mono phenyl ethers (PPEs) with different degrees of ethoxylation. The retention factor was increased with increase in the number of ethylene oxide groups and a good separation of the PPE homologs was achieved by smectite-EKC. The RSD of the migration time, plate number, and peak area were 0.60, 8.3, and 2.7% (n = 5), respectively. The developed method can be applied to the analysis of PPEs in commercially available consumer products without any sample pretreatments. In addition, ca. 100-fold sensitivity enhancements for the PPEs with high retention factors were obtained by sweeping.

12.
Food Addit Contam ; 24(8): 799-806, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17613066

RESUMO

Guidelines for the oxyethylene group (EO) content of polysorbates are set by the Food and Agriculture Organization/World Health Organization Joint Expert Committee on Food Additives. However, the classical titration method for EO determination is difficult and time-consuming. Here, we show that quantitative (1)H-nuclear magnetic resonance spectroscopy can determine the EO contents of polysorbates rapidly and simply. The EO signals were identified through comparisons with sorbitan monolaurate and poly(ethylene glycol) distearate. Potassium hydrogen phthalate was used as an internal standard. The EO contents were estimated from the ratio of the signal intensities of EO to the internal standard. Two nuclear magnetic resonance systems were used to validate the proposed method. The EO content of commercial polysorbates 20, 60, 65, and 80 was determined to be within the recommended limits using this technique. Our approach thus represents an additional or alternative method of determining the EO contents of polysorbates.


Assuntos
Óxido de Etileno/análise , Polissorbatos/análise , Tensoativos/análise , Óxido de Etileno/química , Aditivos Alimentares/análise , Espectroscopia de Ressonância Magnética/métodos , Polissorbatos/química , Tensoativos/química
13.
J Chromatogr A ; 1139(1): 136-42, 2007 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-17118377

RESUMO

A simple, rapid and simultaneous determination of four types of amphoteric surfactants, i.e., C8, C10, C12, C14, C16 and C18-homologues of alkyldimethylamine N-oxide (AO), alkylamidopropylamine N-oxide (APAO), alkylbetaine (Bt) and alkylamidopropylbetaine (APB), was performed by using capillary electrophoresis (CE) with indirect UV detection. To optimize the separation conditions, effects of pH of background solution (BGS), organic modifier and chromophore for indirect UV detection on the CE separation of the amphoteric compounds were investigated. Addition of 50% (v/v) acetonitrile to the BGS under a lower pH condition brought a good separation performance due to the suppression of micelle formation for the analytes and the adsorption onto the inner surface of the capillary. Under an optimal condition, the 24 amphoteric analytes were completely separated in a single run within 17min. The relative standard deviation of the migration time was ranging from 0.20 to 0.23% and the limit of detection values for AO, APAO, Bt and APB homologues were 10-20, 20, 20-50 and 50microg/mL, respectively. Furthermore, the developed method can provide a high resolution separation of the amphoteric surfactants in commercially available detergents and shampoo without any sample pretreatments.


Assuntos
Eletroforese Capilar/métodos , Espectrofotometria Ultravioleta/métodos , Tensoativos/análise , Concentração de Íons de Hidrogênio , Estrutura Molecular , Reprodutibilidade dos Testes , Tensoativos/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...