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Solute transport during rapid and repeated thermal cycle in additive manufacturing (AM) leading to non-equilibrium, non-uniform microstructure remains to be studied. Here, a fully-coupled fluid dynamics and microstructure modelling is developed to rationalise the dynamic solute transport process and elemental segregation in AM, and to gain better understanding of non-equilibrium nature of intercellular solute segregation and cellular structures at sub-grain scale during the melting-solidification of the laser powder bed fusion process. It reveals the solute transport induced by melt convection dilutes the partitioned solute at the solidification front and promotes solute trapping, and elucidates the mechanisms of the subsequent microstructural morphology transitions to ultra-fine cells and then to coarse cells. These suggest solute trapping effect could be made used for reducing crack susceptibility by accelerating the solidification process. The rapid solidification characteristics exhibit promising potential of additive manufacturing for hard-to-print superalloys and aid in alloy design for better printability.
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BACKGROUND: We report a rare case of a large congenital hemangioma (CH) in the maxillofacial region in a female neonate that caused thrombocytopenia and heart failure. With close multidisciplinary collaboration, the congenital hemangioma was successfully resected with good results. CASE SUMMARY: The patient was delivered at gestational age of 36 wk by cesarean section due to cephalopelvic disproportion and lack of onset of labor (birth weight: 2630 g). A right-sided facial tumor was detected in the fetus during routine antenatal ultrasound examination of the mother at 32 wk of gestation. Physical examination revealed a 7 cm × 7 cm × 3 cm hard, dull purple-colored mass on the right maxillofacial region. The mass was tense and had prominent surface telangiectasias. Laboratory investigations revealed reduced hemoglobin and platelet count, and increased activated partial thromboplastin time, prothrombin time, and thrombin time. International normalized ratio, fibrin degradation products, and D-Dimer levels were significantly increased. Thromboelastography showed increased alpha angle, mean amplitude, and the clot formation speed. Thyroid-stimulating hormone level was significantly elevated. The patient was administered prednisone, propranolol, euthyrox, vitamin K1, milrinone, and digoxin. After operation, cefepime was administered for anti-infection and propranolol was prescribed at discharge. CONCLUSION: We report a rare case of CH in the right maxillofacial region causing thrombocytopenia and heart failure.
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Recent studies have suggested that the regulation of endogenous neural stem cells (NSCs) or transplanting of exogenous nerve cells are the newest and most promising methods for the treatment of dementia and other neurological diseases. The special location and limited number of endogenous NSCs, however, restrict their clinical application. The success in directional differentiation of exogenous stem cells from other tissue sources into neural cells has provided a novel source for NSCs. Study on the relative mechanisms is still at the preliminary stage. Currently the induction methods include: 1) cell growth factor induction; 2) chemical induction; 3) combined growth factor-chemical induction; or 4) other induction methods such as traumatic brain tissue homogenate, gene transfection, traditional Chinese medicine, and coculture induction. Cerebrospinal fluid (CSF), as a natural medium under physiological conditions, contains a variety of progrowth peptide factors that can promote the proliferation and differentiation of mesenchymal stromal cells (MSCs) into neural cells through the corresponding receptors on the cell surface. This suggests that CSF can not only nourish the nerve cells, but also become an effective and suitable inducer to increase the yield of NSCs. However, some other studies believed that CSF contained certain inhibitory components against the differentiation of primary stem cells into mature neural cells. Based on the above background, here we review the relative literature on the influence of the CSF on stem cells in order to provide a more comprehensive reference for the wide clinical application of NSCs in the future.
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Técnicas de Reprogramación Celular/métodos , Líquido Cefalorraquídeo/metabolismo , Péptidos y Proteínas de Señalización Intercelular/líquido cefalorraquídeo , Trasplante de Células Madre Mesenquimatosas/métodos , Enfermedades del Sistema Nervioso/terapia , Animales , Humanos , Péptidos y Proteínas de Señalización Intercelular/farmacología , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/efectos de los fármacos , Células-Madre Neurales/citologíaRESUMEN
Mesenchymal stem cells (MSCs) have been shown to be able to inhibit cancer cells growth. In this study, we investigate the role and the molecular mechanism of hypoxia-inducible factor 1-alpha (HIF-1α) in inhibition of cancer cell proliferation by human MSCs through depletion and overexpression of HIF-1α in human MSCs. We found that the cell culture medium from HIF-1α-depleted Z3 cells significantly promotes breast cancer MCF-7 cell proliferation and colony formation. The expression of p21 is increased in MCF-7 cells, but p53 level remains unchanged. In contrast, the cultured medium from HIF-1α-overexpressed Z3 cells dramatically inhibits MCF-7 cell proliferation and colony formation. The expression of p21 is inhibited in MCF-7 cells, but p53 does not change. We conclude HIF-1α promotes inhibitory effect of human MCSs on breast cancer cell proliferation and colony formation. This process is tightly correlated with cell cycle protein p21 level in cancer cells.
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Neoplasias de la Mama/patología , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Células Madre Mesenquimatosas/citología , Neoplasias de la Mama/metabolismo , Hipoxia de la Célula , Proliferación Celular , Medios de Cultivo/química , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Células MCF-7 , Trasplante de Células Madre , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
Atractylenolide II (AII) and atractylenolide III (AIII) are the major active components in Atractylodes Macrocephala Rhizoma (AMR). In this study, a sensitive, rapid and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of AII and AIII in rat plasma using loliolide as internal standard (IS). After protein precipitation with ethyl acetate, the analytes were injected into an LC-MS/MS system for quantification. Chromatography was performed using a C(18) column, eluting with water and acetonitrile (45:55, v/v) at 0.2 mL/min. All analytes including IS were monitored under positive ionization conditions by multiple reaction monitoring with an electrospray ionization source. The validated method was successfully applied to the pharmacokinetic study of AII and AIII in rat plasma after oral administration of AMR extract. The results provided a meaningful basis for evaluating the clinical applications of traditional Chinese medicine.
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Atractylodes/química , Cromatografía Liquida/métodos , Lactonas/sangre , Sesquiterpenos/sangre , Espectrometría de Masas en Tándem/métodos , Administración Oral , Animales , Estabilidad de Medicamentos , Lactonas/química , Lactonas/farmacocinética , Masculino , Extractos Vegetales/administración & dosificación , Extractos Vegetales/farmacocinética , Ratas , Ratas Sprague-Dawley , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Sesquiterpenos/química , Sesquiterpenos/farmacocinéticaRESUMEN
AIM: To investigate chemical constituents of Spatholobus suberectus Dunn. METHODS: Isolation and purification were carried out by column chromatographic methods. Compounds were characterized based on their physical characteristics and spectra data. RESULTS: Seventeen compounds were isolated from ethanol extract of S. suberectus. The structures were elucidated as prestegane B (1), (2R, 3R)-buteaspermanol (2), (+)-medioresinol (3), (2R, 3R)-3,7-dihydroxyflavanone (4), benzeneethanol (5), 4, 7, 2'-trihydroxy-4'-methoxyisoflavanol (6), naringenin (7), blumenol A (8), protocatechuic acid ethyl ester (9), liquiritigenin (10), 7, 4'-dihydroxy-8-methoxy-isoflavone (11), 3, 5, 7, 3', 5'-pentahydroxyflavanone (12), protocatechuic acid (13), glycyroside (14), 8-methylretusin-7-O-ß-D-glucopyranoside (15), 3, 3', 4', 5, 6, 7, 8-heptahydroxyflavan (16), and dulcisflavan (17). CONCLUSION: All compounds are firstly isolated from the title plant and compounds 1, 3 were isolated from the Spatholobus genus for the first time.
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Fabaceae/química , Extractos Vegetales/química , 4-Butirolactona/análogos & derivados , 4-Butirolactona/química , 4-Butirolactona/aislamiento & purificación , Lignanos/química , Lignanos/aislamiento & purificación , Estructura MolecularRESUMEN
INTRODUCTION: Atractylodes Macrocephala Rhizoma (AMR) is a traditional Chinese medicine containing several sesquiterpenoids with a series of effects. These bioactive compounds may be used as chemical markers for the quality control of AMR. It is necessary to optimise the extraction method and conditions in order to improve extraction productivity. OBJECTIVE: To develop a simple and effective method for the extraction of sesquiterpenoids from AMR and then to simultaneously determine four sesquiterpenoids, selina-4 (14), 7(11)-dien-8-one (SA), atractylenolide II (AII), atractylenolide III (AIII) and atractylenolide VII (AVII), in AMR. METHODOLOGY: Ultrasound-assisted extraction (UAE) was optimised by central composite design (CCD) to obtain the maximum efficiency. The gas chromatography method was validated and applied for the quantification of four sesquiterpenoids. RESULTS: The optimum values of factors were: particle size (120 mesh), extraction time (26 min), extraction temperature (39°C) and 31 mL of chloroform. The selectivity, linear range, limits of detection (LOD) and quantification (LOQ), accuracy, precision and repeatability of the method developed indicated its validity. The application of the method showed that the contents of four sesquiterpenoids in AMR were rather variable. CONCLUSION: The results indicated that the described GC method could be used for the quality control of AMR and its related preparations. Meanwhile, this research revealed that UAE under optimum conditions could be considered as a powerful tool for the extraction of phytochemicals from plants.