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The multifaceted process of nerve regeneration following damage remains a significant clinical issue, due to the lack of a favorable regenerative microenvironment and insufficient endogenous biochemical signaling. However, the current nerve grafts have limitations in functionality, as they require a greater capacity to effectively regulate the intricate microenvironment associated with nerve regeneration. In this regard, we proposed the construction of a functional artificial scaffold based on a "two-pronged" approach. The whole system was developed by encapsulating Tazarotene within nanomicelles formed through self-assembly of reactive oxygen species (ROS)-responsive amphiphilic triblock copolymer, all of which were further loaded into a thermosensitive injectable hydrogel. Notably, the hydrogel exhibits obvious temperature sensitivity at a concentration of 6 wtâ¯%, and the nanoparticles possess concentration-dependent H2O2-response capability with a controlled release profile in 48 h. The combined strategy promoted the repair of injured peripheral nerves, attributed to the dual role of the materials, which mainly involved providing structural support, modulating the immune microenvironment, and enhancing angiogenesis. Overall, this study opens up intriguing prospects in tissue engineering.
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Sistemas de Liberación de Medicamentos , Peróxido de Hidrógeno , Peróxido de Hidrógeno/farmacología , Ingeniería de Tejidos , Hidrogeles/farmacología , Hidrogeles/química , Nervios Periféricos/fisiología , Regeneración NerviosaRESUMEN
The oriented growth of ß-Ga2 O3 films has triggered extensive interest due to the remarkable and complex anisotropy found in the ß-Ga2 O3 bulks. Remarkable properties, including stronger solar-blind ultraviolet (SBUV) absorption, better mobility, and higher thermal conductivity, are usually observed along <010> direction as compared to other low-index axes. So far, <010>-oriented ß-Ga2 O3 film growth has been hindered by the lack of suitable substrates and higher surface energy of the (010) crystal plane. Herein, the first growth of uniquely <010>-oriented ß-Ga2 O3 films on quartz substrates by laser chemical vapor deposition (LCVD) are reported. By investigating the effects of deposition temperature (Tdep ) and O2 flow rate (RO2 ) on the growth of ß-Ga2 O3 films, it is found that the formation of <010> orientation is closely related to the higher stability of oxygen close-packed planes under O-rich condition. As a result, a grain size of up to ≈2 µm and a deposition rate of up to ≈ 40 µm h-1 are obtained. Metal-semiconductor-metal (MSM) type detector based on <010>-oriented ß-Ga2 O3 film exhibits ultra-fast response speed, 1-2 orders of magnitude higher than those of most detectors based on ß-Ga2 O3 films with other orientations.
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In this study, the significance of oxidized low-density lipoprotein (ox-LDL) in promoting the progression of atherosclerosis was investigated by inducing the differentiation of macrophages into the M2 subtype within a high-fat diet-induced ApoE -/- mouse model. The study also evaluated the effects of ß2-AR agonists and blockers on this process. Ox-LDL was found to have significantly promoted the differentiation of macrophages into the M2 type and induced related functional alterations. Furthermore, it activated the pyroptosis pathway and encouraged the release of lactate dehydrogenase. The administration of ß2-AR agonists intensified these processes, while ß2-AR blockers had the opposite effect. In animal experiments, the model group displayed elevated numbers of M2-type macrophages beneath the aortic root intima, an increased rate of plaque destruction, and the formation of atherosclerotic plaques compared to the control group. The SAL (Salbutamol) group exhibited even more severe plaque development than the model group. Conversely, the ICI (ICI118551) group demonstrated M2-type macrophage levels comparable to the control group, with a higher plaque destruction rate than controls but significantly lower than the model group, and no atherosclerotic plaques. These findings suggest that ox-LDL promoted the differentiation of recruited monocytes into M2-type macrophages, leading to a shift in the inflammatory response from M1 to M2 macrophages. This alteration resulted in the persistence of atherosclerotic inflammation, as M2-type macrophages were prone to cell membrane rupture (such as pyroptosis), contributing to the continuous recruitment of circulating monocytes and heightened inflammatory reactions within atherosclerotic plaques. Consequently, this process fueled the progression of atherosclerosis.
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Aterosclerosis , Placa Aterosclerótica , Ratones , Animales , Placa Aterosclerótica/metabolismo , Dieta Alta en Grasa/efectos adversos , Ratones Noqueados para ApoE , Aterosclerosis/metabolismo , Macrófagos , Lipoproteínas LDL/farmacología , Lipoproteínas LDL/metabolismo , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Inflamación/metabolismo , Ratones Endogámicos C57BL , Ratones NoqueadosRESUMEN
BACKGROUND/AIMS: The activation of the complement system and subsequent inflammatory responses are important features of myocardial ischemia/reperfusion (I/R) injury. Exosomes are nanoscale extracellular vesicles that play a significant role in remote ischemic preconditioning (RIPC) cardioprotection. The present study aimed to test whether RIPC-induced plasma exosomes (RIPC-Exo) exert protective effects on myocardial I/R injury by inhibiting complement activation and inflammation and whether exosomal heat shock protein 90 (HSP90) mediates these effects. METHODS: Rat hearts underwent 30 min of coronary ligation followed by 2 h of reperfusion. Plasma exosomes were isolated from RIPC rats and injected into the infarcted myocardium immediately after ligation. Sixty rats were randomly divided into Sham, I/R, I/R + RIPC-Exo (50 µg/µl), and RIPC-Exo + GA (geldanamycin, 1 mg/kg, administration 30 min before ligation) groups. Cardiomyocyte apoptosis, the release of myocardial markers (LDH, cTnI and CK-MB), infarct size, the expression of HSP90, complement component (C)3, C5a, c-Jun N-terminal kinase (JNK), interleukin (IL)-1ß, tumor necrosis factor (TNF)-alpha and intercellular adhesion molecule -1 (ICAM-1) were assessed. RESULTS: RIPC-Exo treatment significantly reduced I/R-induced cardiomyocyte apoptosis, the release of myocardial markers (LDH, cTnI and CK-MB) and infarct size. These beneficial effects were accompanied by decreased C3 and C5a expression, decreased inflammatory factor levels (IL-1ß, TNF-α, and ICAM-1), decreased JNK and Bax, and increased Bcl-2 expression. Meanwhile, the expression of HSP90 in the exosomes from rat plasma increased significantly after RIPC. However, treatment with HSP90 inhibitor GA significantly reversed the cardioprotection of RIPC-Exo, as well as activated complement component, JNK signalling and inflammation, indicating that HSP90 in exosomes isolated from the RIPC was important in mediating the cardioprotective effects during I/R. CONCLUSION: Exosomal HSP90 induced by RIPC played a significant role in cardioprotection against I/R injury, and its function was in part linked to the inhibition of the complement system, JNK signalling and local and systemic inflammation, ultimately alleviating I/R-induced myocardial injury and apoptosis by the upregulation of Bcl-2 expression and the downregulation of proapoptotic Bax.
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Precondicionamiento Isquémico Miocárdico , Precondicionamiento Isquémico , Daño por Reperfusión Miocárdica , Ratas , Animales , Daño por Reperfusión Miocárdica/patología , Molécula 1 de Adhesión Intercelular , Proteína X Asociada a bcl-2 , Factor de Necrosis Tumoral alfa , Activación de Complemento , Inflamación , InfartoRESUMEN
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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OBJECTIVES: This study aims to investigate the clinical value of uric acid in predicting adverse pregnancy outcomes (APOs) of women with hypertensive disorders of pregnancy. MATERIAL AND METHODS: A total of 180 pregnant women with HDP from September 2015 to January 2017 were selected for this study. These subjects were classified into two groups, according to serum uric acid level: high UA group (n = 137) and normal UA group (n = 43). In addition, 180 healthy pregnant women were selected and assigned as the control group (n = 180). The monitored biochemical indices and APOs in these three groups were analyzed. Furthermore, non-conditional logistic regression analysis was performed to determine influencing factors of APOs in women with HDP and hyperuricemia. RESULTS: The non-conditional multi-factor logistic regression analysis revealed that HUA (SUA > 357 umol/L) is the risk factor of APOs in women with HDP (OR = 1.258, P < 0.05). CONCLUSIONS: Women with HDP and HUA are often accompanied with a variety of abnormal biochemical indicators, and is correlated with the severity of the disease and APOs.
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Hipertensión Inducida en el Embarazo/sangre , Resultado del Embarazo , Nacimiento Prematuro/sangre , Ácido Úrico/sangre , Adulto , Biomarcadores/sangre , Estudios de Casos y Controles , Femenino , Humanos , Hipertensión Inducida en el Embarazo/diagnóstico , Recien Nacido Prematuro , Embarazo , Factores de Riesgo , Adulto JovenRESUMEN
BACKGROUND/AIMS: Previous studies have shown that heat shock protein 90 (HSP90)-mediated mitochondrial import of connexin 43 (Cx43) is critical in preconditioning cardioprotection. The present study was designed to test whether postconditioning has the same effect as preconditioning in promoting Cx43 translocation to mitochondria and whether mitochondrial HSP90 modulates this effect. METHODS: Cellular models of hypoxic postconditioning (HPC) from rat heart-derived H9c2 cells and neonatal rat cardiomyocytes were employed. The effects of HPC on cardiomyocytes apoptosis were examined by flow cytometry and Hoechst 33342 fluorescent staining. Reactive oxidative species (ROS) production was assessed with the peroxide-sensitive fluorescent probe 2',7'-dichlorofluorescin in diacetate (DCFH-DA). The anti- and pro-apoptotic markers Bcl-2 and Bax, HSP90 and Cx43 protein levels were studied by Western blot analysis in total cell homogenate and sarcolemmal and mitochondrial fractions. The effects on HPC of the HSP90 inhibitor geldanamycin (GA), ROS scavengers superoxide dismutase (SOD) and catalase (CAT), and small interfering RNA (siRNA) targeting Cx43 and HSP90 were also investigated. RESULTS: HPC significantly reduced hypoxia/reoxygenation (H/R)-induced cardiomyocyte apoptosis. These beneficial effects were accompanied by an increase in Bcl-2 levels and a decrease in Bax levels in both sarcolemmal and mitochondrial fractions. HPC with siRNA targeting Cx43 or the ROS scavengers SOD plus CAT significantly prevented ROS generation and HPC cardioprotection, but HPC with either SOD or CAT did not. These data strongly supported the involvement of Cx43 in HPC cardioprotection, likely via modulation of the ROS balance which plays a central role in HPC protection. Furthermore, HPC increased total and mitochondrial levels of HSP90 and the mitochondria-to-sarcolemma ratio of Cx43; blocking the function of HSP90 with the HSP90 inhibitor geldanamycin (GA) or siRNA targeting HSP90 prevented the protection of HPC and the HPC-induced association of Cx43, indicating that mitochondrial HSP90 was important for mitochondrial translocation of Cx43 during HPC. CONCLUSION: Mitochondrial HSP90 played a central role in HPC cardioprotection, and its activity was linked to the mitochondrial targeting of Cx43, the activation of which triggered ROS signaling and the subsequent reduction of redox stress. Consequently, its target gene, Bcl-2, was upregulated, and proapoptotic Bax was inhibited in the sarcolemma and mitochondria, ultimately attenuating H/R-induced cardiomyocyte apoptosis. These data reveal a novel mechanism of HPC protection.
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Conexina 43/metabolismo , Proteínas HSP90 de Choque Térmico/metabolismo , Animales , Apoptosis/efectos de los fármacos , Benzoquinonas/farmacología , Catalasa/farmacología , Hipoxia de la Célula , Línea Celular , Conexina 43/antagonistas & inhibidores , Conexina 43/genética , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Proteínas HSP90 de Choque Térmico/genética , Lactamas Macrocíclicas/farmacología , Microscopía Fluorescente , Mitocondrias/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/química , Especies Reactivas de Oxígeno/metabolismo , Sarcolema/metabolismo , Superóxido Dismutasa/farmacología , Proteína X Asociada a bcl-2/metabolismoRESUMEN
Resveratrol (RSV), a phytoalexin, has shown to prevent endothelial dysfunction and reduce diabetic vascular complications and the risk of cardiovascular diseases. The aim of this study was to investigate the signaling mechanisms underlying the protecting effects of RSV against endothelial dysfunction during hyperglycemia in vitro and in vivo. Human umbilical vein endothelial cells (HUVECs) were treated with RSV, and then exposed to high glucose (HG, 30 mmol/L). Akt-Ser473 phosphorylation, eNOS-Ser1177 phosphorylation, and PTEN protein levels in the cells were detected using Western blot. For in vivo studies, WT and Akt-/- mice were fed a normal diet containing RSV (400 mg·kg-1·d-1) for 2 weeks, then followed by injection of STZ to induce hyperglycemia (300 mg/dL). Endothelial function was evaluated using aortic rings by assessing ACh-induced vasorelaxation. RSV (5-20 µmol/L) dose-dependently increased Akt-Ser473 phosphorylation, accompanied by increased eNOS-Ser1177 phosphorylation in HUVECs; these effects were more prominent under HG stimulation. Transfection with Akt siRNA abolished RSV-enhanced eNOS phosphorylation and NO release. Furthermore, RSV (5-20 µmol/L) dose-dependently decreased the levels of PTEN, which was significantly increased under HG stimulation, and PTEN overexpression abolished RSV-stimulated Akt phosphorylation in HG-treated HUVECs. Moreover, RSV dramatically increased 26S proteasome activity, which induced degradation of PTEN. In in vivo studies, pretreatment with RSV significantly increased Akt and eNOS phosphorylation in aortic tissues and ACh-induced vasorelaxation, and improved diabetes-induced endothelial dysfunction in wild-type mice but not in Akt-/- mice. RSV attenuates endothelial function during hyperglycemia via activating proteasome-dependent degradation of PTEN, which increases Akt phosphorylation, and consequentially upregulation of eNOS-derived NO production.
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Endotelio Vascular/efectos de los fármacos , Hiperglucemia/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Estilbenos/farmacología , Acetilcolina/farmacología , Animales , Células Cultivadas , Relación Dosis-Respuesta a Droga , Activación Enzimática/efectos de los fármacos , Glucosa/farmacología , Células Endoteliales de la Vena Umbilical Humana , Humanos , Ratones , Ratones Noqueados , Óxido Nítrico Sintasa de Tipo III/metabolismo , Fosfohidrolasa PTEN/metabolismo , Fosforilación , Proteínas Proto-Oncogénicas c-akt/genética , ARN Interferente Pequeño/farmacología , Resveratrol , Vasodilatación/efectos de los fármacosRESUMEN
In this paper, the common errors in medical devices test reports are classified and analyzed. And then the main 11 influence factors for these inspection report errors are summarized. The hierarchy model was also developed and verified by presentation data using MATLAB. The feasibility of comprehensive weights quantitative comparison has been analyzed by using the analytic hierarchy process. In the end, this paper porspects the further research direction.
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Análisis de Falla de Equipo , Equipos y Suministros/normas , Modelos TeóricosRESUMEN
BACKGROUND: Previous studies have shown that heat shock protein 90 (HSP90) plays a vital role in ischemic preconditioning. The present study was designed to explore whether HSP90 might be responsible for cardioprotection in ischemic postconditioning (PostC). MATERIALS AND METHODS: Rat hearts underwent 30 min of regional ischemia and 2 h of reperfusion in situ, and PostC was effected with three cycles of 30-s reperfusion and 30-s coronary artery occlusion at the end of ischemia. Ninety rats were randomized into five groups: sham; ischemia-reperfusion (I/R); PostC; 1 mg/kg HSP90 inhibitor geldanamycin (GA) plus PostC (PostC + GA1); and 5 mg/kg GA plus PostC (PostC + GA5). The GA was administered 10 min before reperfusion. RESULTS: Compared with the I/R group, the PostC group exhibited lower infarct size (46.7 ± 3.0% versus 27.4 ± 4.0%, respectively), release of lactate dehydrogenase and creatine kinase-MB (2252.6 ± 350.8 versus 1713.7 ± 202.4 IU/L, 2804.3 ± 315.7 versus 1846.2 ± 238.0 IU/L, respectively), cardiomyocyte apoptosis (48.4 ± 5.6% versus 27.6 ± 3.8%, respectively), and mitochondrial damage. These beneficial effects were accompanied by an increase in mitochondrial Bcl-2 levels and a decrease in Bax levels. In addition, mitochondrial protein kinase Cepsilon (PKCepsilon) was relatively low in the I/R group but significantly higher in the PostC group, whereas cytosolic PKCepsilon was relatively high in the I/R group but significantly lower in the PostC group, suggesting the translocation of PKCepsilon from cytosol to mitochondria during PostC. However, blocking HSP90 function with GA inhibited the protection of PostC and PKCepsilon mitochondrial translocation. CONCLUSIONS: HSP90 is critical in PostC-induced cardioprotection, and its activity might be linked to mitochondrial targeting of PKCepsilon, the activation of which results in upregulation of its target gene, Bcl-2, and the inhibition of proapoptotic Bax in mitochondria.
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Chaperonina 60/metabolismo , Poscondicionamiento Isquémico , Daño por Reperfusión Miocárdica/metabolismo , Proteína Quinasa C-epsilon/metabolismo , Animales , Apoptosis , Benzoquinonas , Western Blotting , Forma MB de la Creatina-Quinasa/sangre , L-Lactato Deshidrogenasa/sangre , Lactamas Macrocíclicas , Masculino , Mitocondrias/ultraestructura , Infarto del Miocardio/patología , Daño por Reperfusión Miocárdica/prevención & control , Miocardio/metabolismo , Miocardio/patología , Miocitos Cardíacos/ultraestructura , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Proteína X Asociada a bcl-2/metabolismoRESUMEN
OBJECTIVES: The purpose of this study was to investigate whether focal fatty sparing can arise in preexisting nonalcoholic diffuse homogeneous fatty liver and its clinical implications. METHODS: This prospective study consisted of 2 parts. In the first part, 8598 people (5202 men and 3396 women; mean age ± SD, 43.4 ± 28.3 years; range, 18-82 years) were consecutively evaluated with sonography for abnormal liver findings; in the second part, participants with diffuse homogeneous fatty liver were followed over approximately 3 years. Sonographic findings of the participants in the first year and findings of the participants with diffuse homogeneous fatty liver in the first and third years were analyzed. RESULTS: In the first part, 778 of 8598 participants (9.05%) were found to have fatty liver, including 752 cases of nonalcoholic diffuse fatty liver (8.75%) and 26 cases of alcoholic fatty liver (0.30%). Of the 752 cases of nonalcoholic diffuse fatty liver, 301 participants had nonalcoholic diffuse homogeneous fatty liver, and 68 (9.04%) had focal fatty sparing. In the second part, the 301 participants with nonalcoholic diffuse homogeneous fatty liver (205 men and 96 women; mean age, 39.6 ± 10.4 years; range, 18-60 years) were followed. In the third year, 2 cases of fatty liver (0.67%) had resolved, 2 cases (0.67%) had inflammatory pseudotumors, and no focal fatty sparing was found (P < .001). CONCLUSIONS: The findings of this study suggest that focal fatty sparing usually does not arise in preexisting nonalcoholic diffuse homogeneous fatty liver, and a newly emerging abnormality is more likely a true lesion.
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Hígado Graso/diagnóstico por imagen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Hígado/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico/diagnóstico por imagen , Estudios Prospectivos , Factores de Riesgo , Ultrasonografía Doppler en Color/métodos , Adulto JovenRESUMEN
OBJECTIVE: To investigate whether there are ultrasound characteristics that can suggest HCC in ultrasound surveillance of nodules in cirrhotic liver. METHODS: Data from 277 patients with hepatitis B virus-related nodules in cirrhotic liver undergoing ultrasound surveillance of the nodules for malignancy were reviewed. Size of the nodules ranged 6-23 mm. The nodules were followed by color Doppler ultrasound at 3- to 6-month intervals, with focus on size, shape, echogenicity, margin, halo sign, and vasculature. Suspicious malignant nodules underwent contrast-enhanced CT/MRI, and some indeterminate nodules underwent biopsy. RESULTS: Nodules in 189 patients were hypo/isoechoic/faint high echoic, 23 were hyperechoic, and 65 were both hypo/isoechoic/faint high echoic and hyperechoic. Forty-two patients developed hepatocellular carcinoma: 35 from nodules and 7 from background parenchyma. Fourteen nodules recessed (size >10 mm), 11 new nodules emerged (size >10 mm), and the total number of nodules increased over 5 years. All hepatocellular carcinomas developed from hypo/isoechoic/faint high echoic nodules, and no typical hyperechoic nodules developed into hepatocellular carcinomas. The size increased significantly when the nodules developed into hepatocellular carcinomas. No nodule presented an overt halo, seven hepatocellular carcinomas developed from nodules with a halo, and ill-defined margins of 16 nodules became well defined when they developed into hepatocellular carcinomas. No vasculature was detectable in the nodules, while it was detectable in eight hepatocellular carcinomas. No significant change occurred in nodules without malignancy. CONCLUSION: The characteristics for dynamic surveillance of nodules in cirrhotic liver for malignancy should include nodule growth, margin, halo, and vasculature. Apart from evident growth, an ill-defined margin becoming a well-defined margin, a newly emerged halo, and newly detectable vasculature are strongly suggestive of nodule malignancy.
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Gallium oxide (Ga2O3), as a new kind of ultra-wide band gap semiconductor material, is widely studied in many fields, such as power electronics, UV - blind photodetectors, solar cells and so on. Owing to the advantages of its excellent performance and broad application prospects in semiconductor technology, Ga2O3 materials have attracted extensive academic and technological attention. This review mainly focuses on introducing the main liquid-phase synthesis methods of Ga2O3 nanoparticles, such as direct-precipitation, chemical bath deposition, hydrothermal, solvothermal, and sol-gel method, including the characteristics in process and advantages and disadvantages of these methods. Then, the effects of reaction conditions, such as pH, capping agent, aging and calcination conditions, on the morphologies and sizes of the precursor and the final products were elucidated. Moreover, the applications of Ga2O3 particles in the fields of catalysis, gas sensors, and other devices in current research on Ga2O3 nanomaterials are discussed with the description of the basic working principle and influence factors.
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The synthesis of highly efficient NiFe-layered double hydroxides (NiFe-LDHs) to catalyze the oxygen evolution reaction (OER) is urgent and challenging. Herein, NiFe-FeCl3-x and NiFe-FeCl2-x samples (where FeCl3 and FeCl2 represent the Fe sources and x represents the imposed reaction time: 6, 12, and 24 h) were prepared via one-pot hydrothermal synthesis using Fe sources characterized by Fe(III) or Fe(II) valence states. In the presence of triethanolamine, when FeCl3 was used as the Fe source, pure NiFe-LDH was obtained, whose crystallinity increased with increasing hydrothermal treatment time. In contrast, when FeCl2 was used as the Fe source, a mixture of NiFe-LDH, Fe2O3, and trace amounts of Fe3O4 was obtained. The content of NiFe-LDH in the mixture increased under longer hydrothermal treatment and NiFe-FeCl3-x catalysts exhibited better OER performance than NiFe-FeCl2-x catalysts. Specifically, NiFe-FeCl3-6 afforded the highest OER performance with an overpotential of 246.8 mV at 10 mA cm-2 and a Tafel slope of 46.1 mV dec-1. Herein, we investigated the effects of the valence state of Fe precursors on the structures and OER activities of the prepared catalysts; the mechanism of NiFe-LDH formation via hydrothermal synthesis in the presence of triethanolamine was also proposed.
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In recent years, the vitrified bond diamond grinding wheel has been applied widely in automotive, aerospace and machine tools of manufacturing industries. However, the main problems of low intensity and poor wettability between the vitrified bond and diamond abrasive limit its further application. In this study, BaO was added into the basic SiO2-B2O3-Al2O3-R2O vitrified bond system, and the impact of BaO on the wettability, thermal and mechanical behavior of vitrified bond and vitrified bond diamond composites was systematically discussed, respectively. The test indicated that when the vitrified bond containing BaO of 6 wt.% was sintered with diamond abrasive at 750 °C, a continuous barium feldspar phase transition layer between diamond abrasive and the bond was generated, which ameliorated the wet property of the bond-diamond abrasive. The contact angle varied from 59° on the blank sample to 35°, and the expansion coefficient changed from 6.24 × 10-6/K to 5.30 × 10-6/K. The Rockwell hardness and flexural strength of the vitrified bond diamond composites achieved the peaks of 117.5 MPa and 113.6 MPa, respectively, which increased by 20.2% and 16.5% compared with that of sample without the addition of BaO.
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The distribution of second phase particles in the microstructure of composite ceramics affects the mechanical properties, and the intragranular structures often result in better properties compared to the intergranular structures. However, it is difficult to obtain composite ceramics with intragranular structure by conventional route. To produce composite ceramics with an intragranular structure in a simpler route. In this work, starting powders with different phase compositions were obtained by the co-precipitation method, and zirconia toughened alumina (ZTA) composite ceramics were prepared with these starting powders by spark plasma sintering (SPS). The results show that it is easier to fabricate ZTA composite ceramics with an intragranular structure by using composite powders containing amorphous or transition phase Al2O3 as starting materials. The phase composition of the powder prepared by the co-precipitation method after calcination at 1100 °C is θ-Al2O3 and t-ZrO2, and the average grain size after sintering at 1500 °C is 1.04 ± 0.28 µm, and the maximum Vickers hardness and fracture toughness of the specimens reach 19.37 ± 0.43 GPa and 6.18 ± 0.06 MPa·m1/2, respectively. The ZrO2 particles were the core of crystallization and grow together with the Al2O3 matrix, forming the intragranular structure of ZTA ceramics. This work may provide a new idea for preparing composite ceramics with intragranular structure.
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Chronic diabetic wounds are the most common complication for diabetic patients. Due to high oxidative stress levels affecting the entire healing process, treating diabetic wounds remains a challenge. Here, we present a strategy for continuously regulating oxidative stress microenvironment by the catalyst-like magnesium-gallate metal-organic framework (Mg-GA MOF) and developing sprayable hydrogel dressing with sodium alginate/chitosan quaternary ammonium salts to treat diabetic wounds. Chitosan quaternary ammonium salts with antibacterial properties can prevent bacterial infection. The continuous release of gallic acid (GA) effectively eliminates reactive oxygen species (ROS), reduces oxidative stress, and accelerates the polarization of M1-type macrophages to M2-type, shortening the transition between inflammation and proliferative phase and maintaining redox balance. Besides, magnesium ions adjuvant therapy promotes vascular regeneration and neuronal formation by activating the expression of vascular-associated genes. Sprayable hydrogel dressings with antibacterial, antioxidant, and inflammatory regulation rapidly repair diabetic wounds by promoting neurovascular network reconstruction and accelerating re-epithelialization and collagen deposition. This study confirms the feasibility of catalyst-like MOF-contained sprayable hydrogel to regulate the microenvironment continuously and provides guidance for developing the next generation of non-drug diabetes dressings.
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[This corrects the article DOI: 10.1016/j.bioactmat.2023.05.019.].
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BACKGROUND: Tilapia is the common name for a group of cichlid fishes and is one of the most important aquacultured freshwater food fish. Mozambique tilapia and its hybrids, including red tilapia are main representatives of salt tolerant tilapias. A linkage map is an essential framework for mapping QTL for important traits, positional cloning of genes and understanding of genome evolution. RESULTS: We constructed a consensus linkage map of Mozambique tilapia and red tilapia using 95 individuals from two F1 families and 401 microsatellites including 282 EST-derived markers. In addition, we conducted comparative mapping and searched for sex-determining loci on the whole genome. These 401 microsatellites were assigned to 22 linkage groups. The map spanned 1067.6 cM with an average inter-marker distance of 3.3 cM. Comparative mapping between tilapia and stickleback, medaka, pufferfish and zebrafish revealed clear homologous relationships between chromosomes from different species. We found evidence for the fusion of two sets of two independent chromosomes forming two new chromosome pairs, leading to a reduction of 24 chromosome pairs in their ancestor to 22 pairs in tilapias. The XY sex determination locus in Mozambique tilapia was mapped on LG1, and verified in five families containing 549 individuals. The major XY sex determination locus in red tilapia was located on LG22, and verified in two families containing 275 individuals. CONCLUSIONS: A first-generation linkage map of salt tolerant tilapia was constructed using 401 microsatellites. Two separate fusions of two sets of two independent chromosomes may lead to a reduction of 24 chromosome pairs in their ancestor to 22 pairs in tilapias. The XY sex-determining loci from Mozambique tilapia and red tilapia were mapped on LG1 and LG22, respectively. This map provides a useful resource for QTL mapping for important traits and comparative genome studies. The DNA markers linked to the sex-determining loci could be used in the selection of YY males for breeding all-male populations of salt tolerant tilapia, as well as in studies on mechanisms of sex determination in fish.
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Mapeo Cromosómico , Repeticiones de Microsatélite/genética , Sitios de Carácter Cuantitativo/genética , Tolerancia a la Sal/genética , Procesos de Determinación del Sexo/genética , Tilapia/genética , Tilapia/fisiología , Animales , Femenino , Genómica , Masculino , Anotación de Secuencia Molecular , Especificidad de la EspecieRESUMEN
OBJECTIVES: The purpose of this study was to investigate the stability of focal fatty sparing of the liver and its clinical implications. METHODS: This prospective study consisted of 2 parts. In the first part, patients who underwent sonography and computed tomography (CT) or magnetic resonance imaging (MRI) were selected, and abnormal findings including focal and diffuse liver abnormalities were documented. In the second part, patients with nonalcoholic hepatic steatosis and focal fatty sparing were included and underwent follow-up with sonography in the second and third years (study interval, 34-37 months; mean ± SD, 35.9 ± 1.14 months). Some cases of focal fatty sparing that were not appreciable on sonography in the third year were reevaluated with CT. RESULTS: A total of 6781 patients with nonalcoholic hepatic steatosis and focal abnormalities were found among 35,337 people undergoing liver sonography; 2133 underwent CT, MRI, biopsy, or a combination thereof. Eighty-nine of those patients (63 male and 26 female; mean age, 37.6 ± 17.5 years; range, 18-72 years) with hepatic steatosis and focal fatty sparing were finally included. In the second part of the study, focal fatty sparing was appreciable on follow-up sonography in 78 cases (87.6%) and 61 cases (68.5%) in the second and third years, respectively. The hepatic steatosis resolved in the third year in 4 patients, and 26 of 28 cases (92.8%) of focal fatty sparing that were not appreciable on follow-up sonography were found on CT in the third year. CONCLUSIONS: Focal fatty sparing may change with fatty liver changes over time, and it is sometimes not appreciable on sonography, although it is often evident on CT. These findings imply that if differentiation between focal fatty sparing and a tumor is undetermined and follow-up is performed, should any change occur, then an abnormality that is no longer appreciable at follow-up is probably focal fatty sparing rather than a true tumor.