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1.
Molecules ; 29(12)2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38930881

RESUMEN

Anthocyanins, as the most critical water-soluble pigments in nature, are widely present in roots, stems, leaves, flowers, fruits, and fruit peels. Many studies have indicated that anthocyanins exhibit various biological activities including antioxidant, anti-inflammatory, anti-tumor, hypoglycemic, vision protection, and anti-aging. Hence, anthocyanins are widely used in food, medicine, and cosmetics. The green and efficient extraction and purification of anthocyanins are an important prerequisite for their further development and utilization. However, the poor stability and low bioavailability of anthocyanins limit their application. Protein, one of the three essential nutrients for the human body, has good biocompatibility and biodegradability. Proteins are commonly used in food processing, but their functional properties need to be improved. Notably, anthocyanins can interact with proteins through covalent and non-covalent means during food processing, which can effectively improve the stability of anthocyanins and enhance their bioavailability. Moreover, the interactions between proteins and anthocyanins can also improve the functional characteristics and enhance the nutritional quality of proteins. Hence, this article systematically reviews the extraction and purification methods for anthocyanins. Moreover, this review also systematically summarizes the effect of the interactions between anthocyanins and proteins on the bioavailability of anthocyanins and their impact on protein properties. Furthermore, we also introduce the application of the interaction between anthocyanins and proteins. The findings can provide a theoretical reference for the application of anthocyanins and proteins in food deep processing.


Asunto(s)
Antocianinas , Antocianinas/química , Antocianinas/aislamiento & purificación , Humanos , Proteínas/aislamiento & purificación , Proteínas/química , Antioxidantes/química , Antioxidantes/aislamiento & purificación , Antioxidantes/farmacología , Disponibilidad Biológica , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación
2.
Int J Med Sci ; 17(12): 1673-1682, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32714070

RESUMEN

Objective: Type 2 diabetes mellitus (T2DM) is a chronic condition resulting from insulin resistance and insufficient ß-cell secretion, leading to improper glycaemic regulation. Previous studies have found that excessive fat deposits in organs such as the liver and muscle can cause insulin resistance through lipotoxicity that affects ß-cell function. The relationships between fat deposits in pancreatic tissue, the function of ß-cells, the method of visceral fat evaluation and T2DM have been sought by researchers. This study aims to elucidate the role of pancreatic fat deposits in the development of T2DM using quantitative computed tomography (QCT), especially their effects on islet ß-cell function. Methods: We examined 106 subjects at the onset of T2DM who had undergone abdominal QCT. Estimated pancreatic fat and liver fat were quantified using QCT and calculated. We analysed the correlations with Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) scores and other oral glucose tolerance test-derived parameters that reflect islet function. Furthermore, correlations of estimated pancreatic fat and liver fat with the area under the curve for insulin (AUCINS) and HOMA-IR were assessed with partial correlation analysis and demonstrated by scatter plots. Results: Associations were found between estimated liver fat and HOMA-IR, AUCINS, the modified ß-cell function index (MBCI) and Homeostatic Model Assessment ß (HOMA-ß). However, no significant differences existed between estimated pancreas fat and those parameters. Similarly, after adjustment for sex, age and body mass index, only estimated liver fat was correlated with HOMA-IR and AUCINS. Conclusions: This study suggests no significant correlation between pancreatic fat deposition and ß-cell dysfunction in the early stages of T2DM using QCT as a screening tool. The deposits of fat in the pancreas and the resulting lipotoxicity may play an important role in the late stage of islet cell function dysfunction as the course of T2DM progresses.


Asunto(s)
Tejido Adiposo/diagnóstico por imagen , Diabetes Mellitus Tipo 2/diagnóstico , Células Secretoras de Insulina/patología , Páncreas/diagnóstico por imagen , Tejido Adiposo/patología , Adulto , Glucemia/genética , Índice de Masa Corporal , Diabetes Mellitus Tipo 2/diagnóstico por imagen , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/patología , Femenino , Prueba de Tolerancia a la Glucosa , Humanos , Insulina/metabolismo , Resistencia a la Insulina/genética , Células Secretoras de Insulina/metabolismo , Grasa Intraabdominal/diagnóstico por imagen , Grasa Intraabdominal/metabolismo , Hígado/metabolismo , Hígado/patología , Masculino , Persona de Mediana Edad , Páncreas/patología , Tomografía Computarizada de Emisión
3.
Exp Cell Res ; 341(1): 61-66, 2016 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-26546984

RESUMEN

BACKGROUND AND AIMS: We have previously demonstrated that islet stellate cells (ISCs) exhibiting a similar phenotype to classical pancreatic stellate cells (PSCs) could be isolated from rat islets, where they may contribute to islet fibrosis in type 2 diabetes mellitus (T2DM). This study was designed to determine whether human islets also contain ISC. MATERIALS AND METHODS: Using standard explants techniques, human ISCs were enriched from freshly isolated human islets. Immunofluorescence visualization of markers for PSCs(α-smooth muscle actin;α-SMA), desmin, vimentin, glial fibrillary acidic protein (GFAP) was used to characterize the human ISC. Cell counting kit-8 (CCK-8) was used to assess the proliferation of ISC. The wound-healing assay and the transwell migration were used to assess the migration capacity of ISC. Immunofluorescence against collagen typesI (col-I), collagen typesIII (col-III) and fibronectin (FN) was performed to identify extracellular matrix (ECM) component synthesized by ISC. Adipogenic and osteogenic differentiation were tried to detected stem cell potential. RESULTS: In culture, ISC with triangular shape grow out from human islets. The passaged ISC expressed α-SMA, desmin, vimentin, GFAP and was positive for col-I, col-III and FN. The proliferation and migration ability of ISC was significantly slower than those of PSC. And both the human PSC and ISC were able to differentiate in vitro into adipocyte- and osteoblast-like cells. CONCLUSION: Similar to our previous rat experiment, the current study shows that human islets also contain ISC which is phenotypically similar but not identical to human PSC.


Asunto(s)
Separación Celular , Islotes Pancreáticos/citología , Células Estrelladas Pancreáticas/citología , Células Estrelladas Pancreáticas/metabolismo , Adipogénesis , Biomarcadores/análisis , Técnicas de Cultivo de Célula , Diferenciación Celular , Movimiento Celular , Proliferación Celular , Humanos , Osteogénesis
4.
World J Diabetes ; 15(1): 105-125, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38313853

RESUMEN

BACKGROUND: Development of end-stage renal disease is predominantly attributed to diabetic nephropathy (DN). Previous studies have indicated that myricetin possesses the potential to mitigate the pathological alterations observed in renal tissue. Nevertheless, the precise molecular mechanism through which myricetin influences the progression of DN remains uncertain. AIM: To investigate the effects of myricetin on DN and explore its potential therapeutic mechanism. METHODS: Db/db mice were administered myricetin intragastrically on a daily basis at doses of 50 mg/kg or 100 mg/kg for a duration of 12 wk. Subsequently, blood and urine indexes were assessed, along with examination of renal tissue pathology. Kidney morphology and fibrosis were evaluated using various staining techniques including hematoxylin and eosin, periodic acid-Schiff, Masson's trichrome, and Sirius-red. Additionally, high-glucose culturing was conducted on the RAW 264.7 cell line, treated with 25 mM myricetin or co-administered with the PI3K/Akt inhibitor LY294002 for a period of 24 h. In both in vivo and in vitro settings, quantification of inflammation factor levels was conducted using western blotting, real-time qPCR and ELISA. RESULTS: In db/db mice, administration of myricetin led to a mitigating effect on DN-induced renal dysfunction and fibrosis. Notably, we observed a significant reduction in expressions of the kidney injury markers kidney injury molecule-1 and neutrophil gelatinase associated lipocalin, along with a decrease in expressions of inflammatory cytokine-related factors. Furthermore, myricetin treatment effectively inhibited the up-regulation of tumor necrosis factor-alpha, interleukin-6, and interluekin-1ß induced by high glucose in RAW 264.7 cells. Additionally, myricetin modulated the M1-type polarization of the RAW 264.7 cells. Molecular docking and bioinformatic analyses revealed Akt as the target of myricetin. The protective effect of myricetin was nullified upon blocking the polarization of RAW 264.7 via inhibition of PI3K/Akt activation using LY294002. CONCLUSION: This study demonstrated that myricetin effectively mitigates kidney injury in DN mice through the regulation of macrophage polarization via the PI3K/Akt signaling pathway.

5.
Mol Biotechnol ; 65(11): 1729-1736, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36881252

RESUMEN

Gene editing technology is regarded as a good news to save patients with genetic diseases because of its significant function of specifically changing genetic information. From zinc-finger proteins to transcription activator-like effector protein nucleases gene editing tools are constantly updated. At the same time, scientists are constantly developing a variety of new gene editing therapy strategies, in order to promote gene editing therapy from various aspects and realize the maturity of the technology as soon as possible. In 2016, CRISPR-Cas9-mediated CAR-T therapy was the first to enter the clinical trial stage, indicating that the use of CRISPR-Cas system as the blade of the genetic lancet to save patients is officially on the schedule. The first challenge to achieve this exciting goal is to improve the security of the technology. This review will introduce the gene security issues faced by the CRISPR system as a clinical treatment tool, the current safer delivery methods and the newly developed CRISPR editing tools with higher precision. Many reviews summarize the means of improving the security of gene editing therapy and the comprehensive delivery method, while few articles focus on the threat of gene editing to the genomic security of the treatment target. Therefore, this review focuses on the risks brought by gene editing therapy to the patient genome, which provides a broader perspective for exploring and improving the security of gene editing therapy from two aspects of delivery system and CRISPR editing tools.


Asunto(s)
Sistemas CRISPR-Cas , Edición Génica , Humanos , Terapia Genética , Genoma
6.
Front Nutr ; 9: 853442, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35369091

RESUMEN

Bioaffinity ultrafiltration combined with LC-Orbitrap-MS/MS was applied for the first time to achieve rapid screening and identification of tyrosinase inhibitory peptides (TYIPs) from grass carp scale gelatin hydrolysates. The binding mode of TYIPs with tyrosinase was investigated by molecular docking technology. The whitening effect of TYIPs was further studied by evaluating the tyrosinase activity and melanin content in mouse B16F10 cells. Four new TYIPs were screened from hydrolysates, among which DLGFLARGF showed the strongest tyrosinase inhibition with an IC50 value of 3.09 mM. Molecular docking showed that hydrogen bonds were the main driving force in the interaction between the peptide DLGFLARGF and tyrosinase. The addition of DLGFLARGF significantly inhibited the tyrosinase activity and melanin production of B16F10 melanoma cells. These results suggest that DLGFLARGF is a promising skin whitening agent for the treatment of potential pigment-related diseases.

7.
Materials (Basel) ; 15(12)2022 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-35744206

RESUMEN

The wide Mg alloy sheets produced by hot extrusion usually can easily form an inhomogeneous texture, resulting in anisotropic mechanical properties and poor formability. However, few studies have been carried out on the bulk texture investigation at different areas of as-extruded Mg alloy sheets, especially the Mg alloys with different alloying elements. In this work, the effect of Al on the bulk texture and mechanical properties at different areas for three wide Mg-Al-Zn alloy sheets with different Al contents (Mg-3Al-0.5Zn, Mg-8Al-0.5Zn and Mg-9Al-0.5Zn) are mainly investigated by neutron diffraction. The results showed that a strong and uneven basal texture was formed in the Mg-3Al-0.5Zn sheet. Meanwhile, the intensity of the basal texture was significantly weakened due to the numerous fine precipitates of Mg17Al12 particles, with the Al content increasing, which hinder the grain growth during extrusion, while fine recrystallized grains have a more random orientation. The enhanced tensile properties in Mg-8Al-0.5Zn and Mg-9Al-0.5Zn alloy sheets are ascribed to the cooperation effect of a refined microstructure, precipitates and weakened basal texture. Among the three Mg alloy sheets, the Mg-8Al-0.5Zn alloy sheet has a yield strength of about 270 MPa, an ultimate tensile strength of about 330 MPa and ultimate elongation of about 16% in the extrusion direction, which possesses the most excellent comprehensive mechanical properties.

8.
Front Med (Lausanne) ; 8: 656086, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33748166

RESUMEN

Background and Objective: Glucose fluctuation (GF) has been reported to induce renal injury and diabetic nephropathy (DN). However, the mechanism still remains ambiguous. Mitochondrial energy metabolism, especially aerobic glycolysis, has been a hotspot of DN research for decades. The activation of HIF-1α/miR210/ISCU/FeS axis has provided a new explanation for aerobic glycolysis. Our previous studies indicated quercetin as a potential therapeutic drug for DN. This study aims to evaluate levels of aerobic glycolysis and repressive effect of quercetin via HIF-1α/miR210/ISCU/FeS axis in a cell model of GF. Methods: The mouse glomerular mesangial cells (MCs) were exposed in high or oscillating glucose with or without quercetin treatment. Cell viability was measured by CCK8 assay. Aerobic glycolysis flux was evaluated by lactate acid, pH activity of PFK. Apoptosis level was confirmed by Annexin V-APC/7-AAD double staining and activity of caspase-3. TNF-α and IL-1ß were used to evaluate inflammation levels. Results: GF deteriorated inflammation damage and apoptosis injury in MCs, while quercetin could alleviate this GF-triggered cytotoxicity. GF intensified aerobic glycolysis in MCs and quercetin could inhibit this intensification in a dose-dependent manner. Quercetin prevented activities of two FeS-dependent metabolic enzymes, aconitase, and complex I, under GF injury in MCs. The mRNA expression and protein contents of HIF-1α were increased after GF exposure, and these could be alleviated by quercetin treatment. Knockdown of ISCU by siRNA and Up-regulating of miR-210 by mimic could weaken the effects of quercetin that maintained protein levels of ISCU1/2, improved cell viability, relieved inflammation injury, decreased apoptosis, and reduced aerobic glycolysis switch in MCs. Conclusion: Quercetin antagonizes GF-induced renal injury by suppressing aerobic glycolysis via HIF-1α/miR-210/ISCU/FeS pathway in MCs cell model. Our findings contribute to a new insight into understanding the mechanism of GF-induced renal injury and protective effects of quercetin.

9.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 27(5): 521-3, 2010 Oct.
Artículo en Zh | MEDLINE | ID: mdl-20931529

RESUMEN

Autoimmune diabetes is a T cell-mediated disease characterized by the autoimmune destruction of pancreatic ß-cells and insulin deficiency. It is related to multiple genes. The IDDM1 locus, which lies within the human leukocyte antigen (HLA) and the IDDM2 locus, which is located to the insulin gene region, are two major genetic contributors of susceptibility. Many other loci conferring susceptibility to autoimmune diabetes are being discovered, including PTPN22, CTLA4, IL2RA and IFIH1. In this article, these loci and their possible immunologic mechanisms involved in the pathogenesis of this disease will be reviewed.


Asunto(s)
Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/inmunología , Animales , Diabetes Mellitus Tipo 1/patología , Predisposición Genética a la Enfermedad , Humanos
10.
Artículo en Inglés | MEDLINE | ID: mdl-33013687

RESUMEN

Background: Serum uric acid levels have been shown to be associated with increased risk of diabetes. However, it remains unclear whether uric acid-lowering therapy (ULT) is associated with improved glycemic status. This study aimed to summarize evidence from randomized controlled trials (RCTs) to investigate whether ULT reduces fasting blood glucose (FBG) and glycated hemoglobin A1c (HbA1c) levels. Methods: PubMed, Embase, and the Cochrane Library were searched from inception until April 10, 2019. Moreover, in order to maximize the search for articles on the same topic, the reference lists of included studies, relevant review articles and systematic reviews were reviewed. Parallel RCTs investigating the effect of ULT on FBG or HbA1c levels were considered for inclusion. An English language restriction was applied. Data were screened and extracted independently by two researchers. Meta-analyses were performed using random-effects models to calculate the weighted mean differences (WMDs) and 95% confidence intervals (CIs). Results: Four trials with 314 patients reported the effect of ULT with allopurinol on FBG and 2 trials with 141 patients reported the effect of ULT with allopurinol on HbA1c. Treatment with allopurinol resulted in a significant decrease in FBG (WMD: -0.61 mmol/L, 95% CI: -0.93 to -0.28), but only a trend of reduction in HbA1c (WMD: -0.47%, 95% CI: -1.16 to 0.22). Notably, the subgroup analyses showed that treatment with allopurinol was associated with reduced FBG levels in patients without diabetes (WMD: -0.60 mmol/L, 95% CI: -0.99 to -0.20), but not in patients with diabetes. In addition, the dose of allopurinol treatment ≥200 mg daily resulted in a reduction of FBG levels (WMD: -0.59 mmol/L, 95% CI: -0.95 to -0.23), whereas low-dose allopurinol (<200 mg daily) had no effect on FBG levels. Conclusions: The findings suggest that ULT with allopurinol may be effective at reducing glycemia, but such an improvement does not appear to be observed in patients with diabetes. The findings require confirmation in additional trials with larger sample sizes.


Asunto(s)
Alopurinol/farmacología , Glucemia/efectos de los fármacos , Diabetes Mellitus Tipo 2/sangre , Supresores de la Gota/farmacología , Hemoglobina Glucada/análisis , Humanos
11.
Cell Death Dis ; 11(6): 446, 2020 06 10.
Artículo en Inglés | MEDLINE | ID: mdl-32522976

RESUMEN

Cisplatin is one of the most potent chemotherapy drugs to treat cancers, but its clinical application remains limited due to severe nephrotoxicity. Several approaches have been developed to minimize such side effects, notably including chronotherapy, a well-known strategy based on the circadian clock. However, the component of the circadian clock machinery that particularly responses to the cisplatin stimulation remains unknown, including its functions in cisplatin-induced renal injury. In our present study, we demonstrated that Bmal1, as a key clock gene, was induced by the cisplatin stimulation in the mouse kidney and cultured human HK-2 renal cells. Gain- and loss-of-function studies indicated that Bmal1 facilitated cisplatin-induced renal injury both in vivo and in vitro, by aggravating the cell apoptotic process. More importantly, RNA-seq analysis revealed that Bmal1 triggered the expression of hallmark genes involved in renal hepatization, a critical event accompanied by the injury. At the molecular level, Bmal1 activated the transcription of hepatization-associated genes through direct recruitment to the E-box motifs of their promoters. Our findings suggest that Bmal1, a pivotal mediator induced renal injury in response to cisplatin treatment, and the therapeutic intervention targeting Bmal1 in the kidney may be a promising strategy to minimize the toxic side-effects of cisplatin in its clinical applications.


Asunto(s)
Factores de Transcripción ARNTL/genética , Relojes Circadianos/genética , Cisplatino/efectos adversos , Riñón/lesiones , Riñón/patología , Factores de Transcripción ARNTL/metabolismo , Albúminas/genética , Albúminas/metabolismo , Animales , Línea Celular , Cisplatino/administración & dosificación , Regulación de la Expresión Génica/efectos de los fármacos , Técnicas de Silenciamiento del Gen , Haptoglobinas/genética , Haptoglobinas/metabolismo , Humanos , Riñón/metabolismo , Masculino , Ratones Endogámicos C57BL , Regiones Promotoras Genéticas/genética , Proteínas Quinasas/metabolismo , Factores de Tiempo , Transferrina/genética , Transferrina/metabolismo
12.
Int J Clin Exp Pathol ; 11(9): 4296-4304, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-31949826

RESUMEN

Diabetic nephropathy is a common complication of type 2 diabetes and is related to the epithelial to mesenchymal transition. In this study, we aimed to find whether the RhoA/ROCK pathway affects the development of diabetic nephropathy caused by the epithelial to mesenchymal transition both in vivo and in vitro. The results show that inhibition of the RhoA/ROCK signaling pathway improved the pathology and degree of fibrosis in diabetic nephropathy as determined by hematoxylin and eosin staining and Masson staining. We also found, using immunohistochemistry and quantitative reverse transcription polymerase chain reaction, that a RhoA/Rock inhibitor regulated relative protein and gene expression levels in a dose-dependent manner. Furthermore, the inhibitor improved fibrosis induced by high levels of glucose in HK-2 cells by suppressing E-cadherin, α-SMA, and FSP-1 expression. In conclusion, the RhoA/ROCK signaling pathway plays an important role in the development of diabetic nephropathy and could be a potential therapeutic target for type 2 diabetes.

13.
Materials (Basel) ; 12(1)2018 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-30587787

RESUMEN

Forming magnesium alloys with rare earth elements (La, Gd, Nd, Y, Ce) is a routine method for modifying their microstructure and properties. In the present work, the effect of Ce addition on the microstructure evolution and the mechanical properties of as-extruded Mg-8Al-0.5Zn (AZ80) alloy was investigated. All of the extruded AZ80-xCe (x = 0, 0.2, 0.8 and 1.4 wt %) alloys exhibited equiaxed grains formed by fully dynamic recrystallization, and the grain size of the extruded AZ80 alloy was remarkably reduced by ~56.7% with the addition of 1.4 wt % Ce. Furthermore, the bulk-shaped Al4Ce phase formed when Ce was first added, with the Ce content rising to 0.8 wt % or higher, and Al4Ce particles in both the nano- and micron sizees were well distributed in the primary α-Mg matrix. The area fraction of the Al4Ce particles expanded with increasing Ce content, providing more nuclei for dynamic recrystallization, which could contribute to the grain refinement. The results of the tensile tests in this study showed that Ce addition effectively improved the room temperature formability of the as-extruded AZ80 alloy, without sacrificing strength. The significantly improved mechanical properties were ascribed to excellent grain refinement, weakened texture strength, an increased Schmid factor, and a reduced area fraction of low-angle grain boundaries, all resulting from Ce addition to the as-extruded AZ80 alloy. The contribution of the nano-Al4Ce precipitates on improving the mechanical properties was also discussed in this paper.

14.
Materials (Basel) ; 11(6)2018 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-29861443

RESUMEN

A high extrusion ratio of 166:1 was applied to commercial AZ61 alloy in one step with an extrusion speed of 2.1 m·min-1. The effects of DA (direct aging) treatment on the microstructure and tensile properties of extruded alloy were investigated. The extruded alloy exhibits fine DRXed grains and the average grain size is ~11 µm. After DA treatment at 170 °C, the tensile strength and 0.2% offset yield strength is enhanced from 314 to 336 MPa and from 169 to 191 MPa respectively, sacrificing elongation from 26.5% to 23.3%. The grain size and texture distribution of extruded AZ61 scarcely evolve during the post aging treatment. However, the enhanced strength in peak-aged alloy is mainly caused by the high-density elliptical Mg17Al12 precipitates distributing uniformly along the grain boundaries or within the grains, by precipitation and dispersion hardening. Furthermore, the nano-sized precipitates effectively inhibit grains from coarsening by triggering pinning effects along the grain boundaries at elevated temperature. As a result, the peak-aged alloy exhibits a better superplasticity of 306.5% compared with that of 231.8% of extruded sample. This work provides a practical one-step method for mass-producing Mg alloy sheets with excellent tensile strength and ductility compared with those fabricated by conventional extrusion methods.

15.
Sci Rep ; 7(1): 4540, 2017 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-28674452

RESUMEN

The tensile creep behavior of Al-Cu-Mg alloy and its composite containing in situ nano-sized TiCx were explored at temperatures of 493 K, 533 K and 573 K with the applied stresses in the range of 40 to 100 MPa. The composite reinforced by nano-sized TiCx particles exhibited excellent creep resistance ability, which was about 4-15 times higher than those of the unreinforced matrix alloy. The stress exponent of 5 was noticed for both Al-Cu-Mg alloy and its composite, which suggested that their creep behavior was related to dislocation climb mechanism. During deformation at elevated temperatures, the enhanced creep resistance of the composite was mainly attributed to two aspects: (a) Orowan strengthening and grain boundary (GB) strengthening induced by nano-sized TiCx particles, (b) θ' and S' precipitates strengthening.

16.
Materials (Basel) ; 9(4)2016 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-28773367

RESUMEN

It is found that Li2Sb compound can act as the nucleus of primary Mg2Si during solidification, by which the particle size of primary Mg2Si decreased from ~300 to ~15-25 µm. Owing to the synergistic effect of the Li2Sb nucleus and adsorption-poisoning of Li atoms, the effect of complex modification of Li-Sb on primary Mg2Si was better than that of single modification of Li or Sb. When Li-Sb content increased from 0 to 0.2 and further to 0.5 wt.%, coarse dendrite changed to defective truncated octahedron and finally to perfect truncated octahedral shape. With the addition of Li and Sb, ultimate compression strength (UCS) of Al-20Mg2Si alloys increased from ~283 to ~341 MPa and the yield strength (YS) at 0.2% offset increased from ~112 to ~179 MPa while almost no change was seen in the uniform elongation. Our study offers a simple method to control the morphology and size of primary Mg2Si, which will inspire developing new Al-Mg-Si alloys with improved mechanical properties.

17.
J Diabetes Res ; 2016: 6924593, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26697502

RESUMEN

We previously isolated islet stellate cells (ISCs) from healthy Wistar rat islets. In the present study, we isolated "already primed by diabetic environment" ISCs from islets of Goto-Kakizaki rats, determined the gene profile of these cells, and assessed the effects of these ISCs on beta-cell function and survival. We detected gene expression of ISCs by digital gene expression. INS-1 cell proliferation, apoptosis, and insulin production were measured after being treated with ISCs supernatant (SN). We observed the similar expression pattern of ISCs and PSCs, but 1067 differentially expressed genes. Insulin production in INS-1 cells cultured with ISC-SN was significantly reduced. The 5-ethynyl-2'-deoxyuridine-positive INS-1 cells treated with ISC-SN were decreased. Propidium iodide- (PI-) positive INS-1 cells were 2.6-fold higher than those in control groups. Caspase-3 activity was increased. In conclusion, ISCs presented in fibrotic islet of GK rats might be special PSCs, which impaired beta-cell function and proliferation and increased beta-cell apoptosis.


Asunto(s)
Diabetes Mellitus Tipo 2/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Células Estrelladas Pancreáticas/metabolismo , Animales , Apoptosis/fisiología , Proliferación Celular/fisiología , Diabetes Mellitus Tipo 2/patología , Fibrosis/metabolismo , Fibrosis/patología , Células Secretoras de Insulina/patología , Células Estrelladas Pancreáticas/patología , Ratas
18.
Materials (Basel) ; 9(12)2016 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-28774083

RESUMEN

Nano-SiC particulates (n-SiCp) reinforced Mg-8Al-1Sn (AT81) composites with different pre-oxidation parameters were fabricated by powder metallurgy (P/M) process combined with hot extrusion. The effects of pre-oxidization treatment of n-SiCp on the microstructure and tensile properties of 0.5 vol % n-SiCp/AT81 composites were investigated accordingly. The distribution of n-SiCp with different pre-oxidation parameters was homogeneous in the composites. Moreover, it was found that a thin MgAl2O4 layer formed at the interface when the n-SiCp were pre-oxidized at 1073 K for 2 h, while the MgAl2O4 layer became much thicker with pre-oxidization temperature increasing to 1273 K for 2 h. After an appropriate pre-oxidization treatment of n-SiCp at 1073 K for 2 h, the as-extruded 0.5 vol % n-SiCp/AT81 composites exhibited an enhanced strength. It was found that the yield strength (YS) and ultimate tensile strength (UTS) increased from 168 MPa and 311 MPa to 255 MPa and 393 MPa compared with the as-extruded AT81 alloy, reflecting 51.8% and 26.4% increments, respectively. The improvement of mechanical properties should be mainly attributed to the grain refinement and homogeneous distribution of n-SiCp in the composites. Moreover, a well-bonded interface and the formation of an appropriate amount of interfacial product (MgAl2O4) benefited the material's mechanical properties.

19.
Oncotarget ; 6(35): 37054-65, 2015 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-26496027

RESUMEN

Emerging evidence indicates that the islet fibrosis is attributable to activation of islet stellate cells (ISCs). In the present study, we compared the differences in biological activity of ISCs isolated from diabetic db/db and non-diabetic db/m mice, and the effects of the regenerating islet-derived protein 1 (Reg1) on ISC function. We showed that ISCs isolated from db/db mice were activated more rapidly than those from db/m mice during culture. Both Reg1 and its putative receptor exostosin-like glycosyltransferase 3 (EXTL3) were highly expressed by diabetic ISCs. Treatment with Reg1 inhibited migration, viability, and synthesis and secretion of Type I Collagen(Col-I), Type III Collagen(Col-III) and Fibronectin(FN) by diabetic ISCs, and this was associated with deactivation of the PI3K/Akt, MAPK/Erk1/2 signaling pathway in an EXTL3-dependent manner. In conclusion, our observations (i) confirmed the presence of fibrogenic stellate cells within pancreatic islets, which are prone to be activated in Type 2 diabetes, and (ii) revealed a potential role for Reg1 in preventing ISC activation.


Asunto(s)
Diabetes Mellitus Experimental/fisiopatología , Diabetes Mellitus Tipo 2/fisiopatología , Islotes Pancreáticos/citología , Litostatina/metabolismo , N-Acetilglucosaminiltransferasas/metabolismo , Animales , Apoptosis , Western Blotting , Movimiento Celular , Proliferación Celular , Células Cultivadas , Técnica del Anticuerpo Fluorescente , Técnicas para Inmunoenzimas , Islotes Pancreáticos/metabolismo , Litostatina/genética , Masculino , Ratones , Ratones Endogámicos C57BL , N-Acetilglucosaminiltransferasas/genética , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Cicatrización de Heridas
20.
Materials (Basel) ; 8(12): 8839-8849, 2015 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-28793749

RESUMEN

Nano-sized TiCx/2009Al composites (with 5, 7, and 9 vol% TiCx) were fabricated via the combustion synthesis of the 2009Al-Ti-CNTs system combined with vacuum hot pressing followed by hot extrusion. In the present study, CNTs were used as the carbon source to synthesize nano-sized TiCx particles. An attempt was made to correlate the effect of ground CNTs by milling and the distribution of synthesized nano-sized TiCx particles in 2009Al as well as the tensile properties of nano-sized TiCx/2009Al composites. Microstructure analysis showed that when ground CNTs were used, the synthesized nano-sized TiCx particles dispersed more uniformly in the 2009Al matrix. Moreover, when 2 h-milled CNTs were used, the 5, 7, and 9 vol% nano-sized TiCx/2009Al composites had the highest tensile properties, especially, the 9 vol% nano-sized TiCx/2009Al composites. The results offered a new approach to improve the distribution of in situ nano-sized TiCx particles and tensile properties of composites.

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