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

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Small ; : e2403079, 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38829022

RESUMEN

Phosphate-based electrolyte propels the advanced battery system with high safety. Unfortunately, restricted by poor electrochemical stability, it is difficult to be compatible with advanced lithium metal anodes and Ni-rich cathodes. To alleviate these issues, the study has developed a phosphate-based localized high-concentration electrolyte with a nitrate-driven solvation structure, and the nitrate-derived N-rich inorganic interface shows excellent performance in stabilizing the LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode interface and modulating the lithium deposition morphology on the anode. The results show that the Li|| NCM811 cell has exceptional long-cycle stability of >80% capacity retention after 800 cycles at 4.3 V, 1 C. A more prominent capacity retention rate of 93.3% after 200 cycles can be reached with the high voltage of 4.5 V. While being compatible with the phosphate-based electrolyte with good flame retardancy and the good electrochemical stability of Ni-rich lithium metal battery (LMBs) systems, the present work expands the construction of anion-rich solvation structures, which is expected to promote the development of the high-performance LMBs with safety.

2.
Small ; : e2403871, 2024 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-39004859

RESUMEN

The slow reaction kinetics and severe shuttle effect of lithium polysulfide make Li-S battery electrochemical performance difficult to meet the demands of large electronic devices such as electric vehicles. Based on this, an electrocatalyst constructed by metal phase material (MoS2) and semiconductor phase material (SnS2) with ohmic contact is designed for inhibiting the dissolution of lithium polysulfide with improving the reaction kinetics. According to the density-functional theory calculations, it is found that the heterostructured samples with ohmic contacts can effectively reduce the reaction-free energy of lithium polysulfide to accelerate the sulfur redox reaction, in addition to the excellent electron conduction to reduce the overall activation energy. The metallic sulfide can add more sulfophilic sites to promote the capture of polysulfide. Thanks to the ohmic contact design, the carbon nanotube-MoS2-SnS2 achieved a specific capacity of 1437.2 mAh g-1 at 0.1 C current density and 805.5 mAh g-1 after 500 cycles at 1 C current density and is also tested as a pouch cell, which proves to be valuable for practical applications. This work provides a new idea for designing an advanced and efficient polysulfide catalyst based on ohmic contact.

3.
Small ; : e2402123, 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38804876

RESUMEN

The localized high-concentration electrolyte (LHCE) propels the advanced high-voltage battery system. Sulfone-based LHCE is a transformative direction compatible with high energy density and high safety. In this work, the application of lithium bis(trifluoromethanesulphonyl)imide and lithium bis(fluorosulfonyl)imide (LiFSI) in the LHCE system constructed from sulfolane and 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) is investigated. The addition of diluent causes an increase of contact ion pairs and ionic aggregates in the solvation cluster and an acceptable quantity of free solvent molecules. A small amount of LiFSI as an additive can synergistically decompose with TTE on the cathode and participate in the construction of both electrode interfaces. The designed electrolyte helps the Ni-rich system to cycle firmly at a high voltage of 4.5 V. Even with high mass load and lean electrolyte, it can keep a reversible specific capacity of 91.5% after 50 cycles. The constructed sulfone-based electrolyte system exhibits excellent thermal stability far beyond the commercial electrolytes. Further exploration of in-situ gelation has led to a quick conversion of the designed liquid electrolyte to the gel state, accompanied by preserved stability, which provides a direction for the synergistic development of LHCE with gel electrolytes.

4.
Acta Pharmacol Sin ; 45(2): 366-377, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37770579

RESUMEN

Diabetic nephropathy (DN) is characterized by chronic low-grade renal inflammatory responses, which greatly contribute to disease progression. Abnormal glucose metabolism disrupts renal lipid metabolism, leading to lipid accumulation, nephrotoxicity, and subsequent aseptic renal interstitial inflammation. In this study, we investigated the mechanisms underlying the renal inflammation in diabetes, driven by glucose-lipid metabolic rearrangement with a focus on the role of acetyl-CoA synthetase 2 (ACSS2) in lipid accumulation and renal tubular injury. Diabetic models were established in mice by the injection of streptozotocin and in human renal tubular epithelial HK-2 cells cultured under a high glucose (HG, 30 mmol/L) condition. We showed that the expression levels of ACSS2 were significantly increased in renal tubular epithelial cells (RTECs) from the diabetic mice and human diabetic kidney biopsy samples, and ACSS2 was co-localized with the pro-inflammatory cytokine IL-1ß in RTECs. Diabetic ACSS2-deficient mice exhibited reduced renal tubular injury and inflammatory responses. Similarly, ACSS2 knockdown or inhibition of ACSS2 by ACSS2i (10 µmol/L) in HK-2 cells significantly ameliorated HG-induced inflammation, mitochondrial stress, and fatty acid synthesis. Molecular docking revealed that ACSS2 interacted with Sirtuin 1 (SIRT1). In HG-treated HK-2 cells, we demonstrated that ACSS2 suppressed SIRT1 expression and activated fatty acid synthesis by modulating SIRT1-carbohydrate responsive element binding protein (ChREBP) activity, leading to mitochondrial oxidative stress and inflammation. We conclude that ACSS2 promotes mitochondrial oxidative stress and renal tubular inflammation in DN by regulating the SIRT1-ChREBP pathway. This highlights the potential therapeutic value of pharmacological inhibition of ACSS2 for alleviating renal inflammation and dysregulation of fatty acid metabolic homeostasis in DN. Metabolic inflammation in the renal region, driven by lipid metabolism disorder, is a key factor in renal injury in diabetic nephropathy (DN). Acetyl-CoA synthetase 2 (ACSS2) is abundantly expressed in renal tubular epithelial cells (RTECs) and highly upregulated in diabetic kidneys. Deleting ACSS2 reduces renal fatty acid accumulation and markers of renal tubular injury in diabetic mice. We demonstrate that ACSS2 deletion inhibits ChREBP-mediated fatty acid lipogenesis, mitochondrial oxidative stress, and inflammatory response in RTECs, which play a major role in the progression of diabetic renal tubular injury in the kidney. These findings support the potential use of ACSS2 inhibitors in treating patients with DN.


Asunto(s)
Diabetes Mellitus Experimental , Nefropatías Diabéticas , Humanos , Ratones , Animales , Sirtuina 1/metabolismo , Nefropatías Diabéticas/patología , Acetilcoenzima A/metabolismo , Acetilcoenzima A/uso terapéutico , Diabetes Mellitus Experimental/tratamiento farmacológico , Simulación del Acoplamiento Molecular , Riñón/patología , Factores de Transcripción/metabolismo , Metabolismo de los Lípidos , Glucosa/metabolismo , Ácidos Grasos/metabolismo , Inflamación/metabolismo , Ligasas/metabolismo , Lípidos
5.
Acta Pharmacol Sin ; 41(8): 1111-1118, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32203081

RESUMEN

Some studies have shown that gut microbiota along with its metabolites is closely associated with diabetic mellitus (DM). In this study we explored the relationship between gut microbiota and kidney injuries of early diabetic nephropathy (DN) and its underlying mechanisms. Male SD rats were intraperitoneally injected with streptozotocin to induce DM. DM rats were orally administered compound broad-spectrum antibiotics for 8 weeks. After the rats were sacrificed, their blood, urine, feces, and renal tissues were harvested for analyses. We found that compared with the control rats, DM rats had abnormal intestinal microflora, increased plasma acetate levels, increased proteinuria, thickened glomerular basement membrane, and podocyte foot process effacement in the kidneys. Furthermore, the protein levels of angiotensin II, angiotensin-converting enzyme, and angiotensin II type 1 receptor in the kidneys of DM rats were significantly increased. Administration of broad-spectrum antibiotics in DM rats not only completely killed most intestinal microflora, but also significantly lowered the plasma acetate levels, inhibited intrarenal RAS activation, and attenuated kidney damage. Finally, we showed that plasma acetate levels were positively correlated with intrarenal angiotensin II protein expression (r = 0.969, P < 0.001). In conclusion, excessive acetate produced by disturbed gut microbiota might be involved in the kidney injuries of early DN through activating intrarenal RAS.


Asunto(s)
Acetatos/metabolismo , Diabetes Mellitus Experimental/fisiopatología , Nefropatías Diabéticas/fisiopatología , Disbiosis/fisiopatología , Microbioma Gastrointestinal/fisiología , Sistema Renina-Angiotensina/fisiología , Acetatos/sangre , Animales , Antibacterianos/farmacología , Diabetes Mellitus Experimental/patología , Nefropatías Diabéticas/patología , Microbioma Gastrointestinal/efectos de los fármacos , Riñón/patología , Masculino , Ratas Sprague-Dawley
6.
Biochem Biophys Res Commun ; 509(2): 596-602, 2019 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-30606480

RESUMEN

BACKGROUND: Platelet microparticles (PMPs) are closely associated with diabetic macrovascular complications. This study aimed to explore the underlying mechanisms of high glucose-induced PMPs generation. METHODS: Washed platelets, obtained from the plasma of healthy male Sprague-Dawley rats, were incubated with high glucose. PMPs were isolated using gradient centrifugation and counted by flow cytometry. Expression and activity of ROCK1 and caspase3 were evaluated by real-time PCR, Western blotting, and activity assay kit. RESULTS: High glucose enhanced PMPs shedding in the presence of collagen. The mRNA and protein levels of ROCK1, but not ROCK2, were increased in platelets incubated with high glucose. Y-27632, an inhibitor of ROCK, blocked the increased PMPs shedding induced by high glucose. Expression and activity of caspase3 were elevated in platelets under the high glucose conditions. Z-DVED-FMK, a caspase3 inhibitor, inhibited ROCK1 activity and decreased the PMPs generation under high glucose. CONCLUSION: High glucose increased PMPs shedding via caspase3-ROCK1 signal pathway.


Asunto(s)
Plaquetas/metabolismo , Caspasa 3/metabolismo , Micropartículas Derivadas de Células/metabolismo , Glucosa/metabolismo , Transducción de Señal , Quinasas Asociadas a rho/metabolismo , Animales , Hiperglucemia/metabolismo , Masculino , Ratas Sprague-Dawley
7.
Acta Pharmacol Sin ; 40(7): 989-990, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31015737

RESUMEN

The REFERENCES 1-35 are wrong because of the error in the process of typesetting.

8.
Acta Pharmacol Sin ; 40(4): 468-476, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30446735

RESUMEN

Platelet microparticles (PMPs) are closely associated with diabetic macrovascular complications. The present study aimed to investigate the effects of PMPs in diabetes on aortic vascular endothelial injury and to explore the underlying mechanisms. Peritoneal injection of streptozotocin was used to generate a diabetic rat model in vivo, and human umbilical vein endothelial cells (HUVECs) treated with PMPs were used in vitro. PMP levels in the circulation and aorta tissues were time-dependently increased in streptozotocin-induced diabetic rats at weeks 4, 8, and 12 (P < 0.05). Aspirin significantly inhibited the PMP levels at each time point (P < 0.05). In diabetic rats, the endothelial nitric oxide levels were decreased significantly combined with increased endothelial permeability. PMPs were internalized by HUVECs and primarily accumulated around the nuclei. PMPs inhibited endothelial nitric oxide levels to about 50% and caused approximately twofold increase in reactive oxygen species production. Furthermore, PMPs significantly decreased the endothelial glycocalyx area and expression levels of glypican-1 and occludin (P < 0.05). Interestingly, the PMP-induced endothelial injuries were prevented by raptor siRNA and rapamycin. In conclusion, increased PMPs levels contribute to aortic vascular endothelial injuries in diabetes through activating the mTORC1 pathway.


Asunto(s)
Plaquetas/química , Micropartículas Derivadas de Células/metabolismo , Diabetes Mellitus Experimental/metabolismo , Endotelio Vascular/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Animales , Micropartículas Derivadas de Células/química , Células Cultivadas , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/patología , Endotelio Vascular/patología , Humanos , Masculino , Ratas , Ratas Sprague-Dawley , Estreptozocina
9.
BMC Nephrol ; 20(1): 303, 2019 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-31382919

RESUMEN

BACKGROUND: New non-invasive biomarkers are demanded to identify renal damage in various autoimmune-associated kidney diseases. Glomerular podocyte damage mediated by systemic lupus erythematosus (SLE) plays an important role in the pathogenesis and progression of lupus nephritis (LN). This study evaluated whether the podocyte-derived microparticles (MPs) were novel biomarkers of clinical and histological features in SLE patients with LN. METHODS: A cross-sectional study, including 34 SLE patients and 16 healthy controls, was designed. Urinary annexin V+ podocalyxin+ MPs of all participants were quantified by flow cytometry. The correlation of podocyte-derived MPs with clinical and histological parameters of SLE patients was analysed. RESULTS: The number of annexin V+ podocalyxin+ MPs from urine samples were markly increased in patients with SLE. Furthermore, the level of urinary podocyte-derived MPs was positively correlated with the SLE Disease Activity Index (SLEDAI) score, anti-dsDNA antibody titre, erythrocyte sedimentation rate, and proteinuria. Conversely, it was negatively correlated with the level of complement C3 and serum albumin. The number of urinary podocyte-derived MPs was significantly increased in SLE patients with high activity indices. Receiver operating characteristic (ROC) curves were calculated to assess the power for podocyte-derived MP levels in differentiating between SLE patients with and without LN. Podocyte-derived MP levels were able to differentiate between SLE patients with mild disease activity, as well as those with moderate and above disease activity. SLE patients showed increased podocyte-derived MP excretion into the urine. CONCLUSIONS: These findings suggest that the change in urinary podocyte-derived MP levels could be useful for evaluating and monitoring SLE disease activity.


Asunto(s)
Micropartículas Derivadas de Células , Lupus Eritematoso Sistémico/orina , Podocitos , Anexina A5 , Estudios de Casos y Controles , Micropartículas Derivadas de Células/patología , Distribución de Chi-Cuadrado , Estudios Transversales , Femenino , Citometría de Flujo , Humanos , Lupus Eritematoso Sistémico/patología , Nefritis Lúpica/patología , Nefritis Lúpica/orina , Masculino , Persona de Mediana Edad , Podocitos/química , Podocitos/patología , Podocitos/ultraestructura , Curva ROC , Sialoglicoproteínas , Estadísticas no Paramétricas
10.
Adv Exp Med Biol ; 1165: 195-232, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31399967

RESUMEN

Finding new therapeutic targets of glomerulosclerosis treatment is an ongoing quest. Due to a living environment of various stresses and pathological stimuli, podocytes are prone to injuries; moreover, as a cell without proliferative potential, loss of podocytes is vital in the pathogenesis of glomerulosclerosis. Thus, sufficient understanding of factors and underlying mechanisms of podocyte injury facilitates the advancement of treating and prevention of glomerulosclerosis. The clinical symptom of podocyte injury is proteinuria, sometimes with loss of kidney functions progressing to glomerulosclerosis. Injury-induced changes in podocyte physiology and function are actually not a simple passive process, but a complex interaction of proteins that comprise the anatomical structure of podocytes at molecular levels. This chapter lists several aspects of podocyte injuries along with potential mechanisms, including glucose and lipid metabolism disorder, hypertension, RAS activation, micro-inflammation, immune disorder, and other factors. These aspects are not technically separated items, but intertwined with each other in the pathogenesis of podocyte injuries.


Asunto(s)
Glomeruloesclerosis Focal y Segmentaria/fisiopatología , Podocitos/citología , Podocitos/patología , Humanos , Hipertensión , Inflamación , Trastornos del Metabolismo de los Lípidos , Proteinuria
11.
J Am Soc Nephrol ; 29(11): 2671-2695, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30341150

RESUMEN

BACKGROUND: Glomerular endothelium dysfunction, which plays a crucial role in the pathogenesis of early diabetic nephropathy, might be caused by circulating metabolic abnormalities. Platelet microparticles, extracellular vesicles released from activated platelets, have recently emerged as a novel regulator of vascular dysfunction. METHODS: We studied the effects of platelet microparticles on glomerular endothelial injury in early diabetic nephropathy in rats with streptozotocin-induced diabetes and primary rat glomerular endothelial cells. Isolated platelet microparticles were measured by flow cytometry. RESULTS: Plasma platelet microparticles were significantly increased in diabetic rats, an effect inhibited in aspirin-treated animals. In cultured glomerular endothelial cells, platelet microparticles induced production of reactive oxygen species, decreased nitric oxide levels, inhibited activities of endothelial nitric oxide synthase and SOD, increased permeability of the glomerular endothelium barrier, and reduced thickness of the endothelial surface layer. Conversely, inhibition of platelet microparticles in vivo by aspirin improved glomerular endothelial injury. Further analysis showed that platelet microparticles activated the mammalian target of rapamycin complex 1 (mTORC1) pathway in glomerular endothelial cells; inhibition of the mTORC1 pathway by rapamycin or raptor siRNA significantly protected against microparticle-induced glomerular endothelial injury in vivo and in vitro. Moreover, platelet microparticle-derived chemokine ligand 7 (CXCL7) contributed to glomerular endothelial injury, and antagonizing CXCL7 using CXCL7-neutralizing antibody or blocking CXCL7 receptors with a competitive inhibitor of CXCR1 and CXCR2 dramatically attenuated such injury. CONCLUSIONS: These findings demonstrate a pathogenic role of platelet microparticles in glomerular endothelium dysfunction, and suggest a potential therapeutic target, CXCL7, for treatment of early diabetic nephropathy.


Asunto(s)
Plaquetas/fisiología , Micropartículas Derivadas de Células/fisiología , Diabetes Mellitus Experimental/sangre , Nefropatías Diabéticas/sangre , Glomérulos Renales/patología , Animales , Aspirina/farmacología , Plaquetas/efectos de los fármacos , Plaquetas/patología , Micropartículas Derivadas de Células/efectos de los fármacos , Micropartículas Derivadas de Células/patología , Células Cultivadas , Quimiocinas CXC/fisiología , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Experimental/fisiopatología , Nefropatías Diabéticas/patología , Nefropatías Diabéticas/fisiopatología , Células Endoteliales/patología , Glomérulos Renales/irrigación sanguínea , Glomérulos Renales/efectos de los fármacos , Masculino , Diana Mecanicista del Complejo 1 de la Rapamicina/antagonistas & inhibidores , Diana Mecanicista del Complejo 1 de la Rapamicina/fisiología , Activación Plaquetaria , Ratas , Ratas Sprague-Dawley , Transducción de Señal
12.
Acta Pharmacol Sin ; 39(6): 1022-1033, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29620052

RESUMEN

Inflammation and lipid disorders play crucial roles in synergistically accelerating the progression of diabetic nephropathy (DN). In this study we investigated how inflammation and lipid disorders caused tubulointerstitial injury in DN in vivo and in vitro. Diabetic db/db mice were injected with 10% casein (0.5 mL, sc) every other day for 8 weeks to cause chronic inflammation. Compared with db/db mice, casein-injected db/db mice showed exacerbated tubulointerstitial injury, evidenced by increased secretion of extracellular matrix (ECM) and cholesterol accumulation in tubulointerstitium, which was accompanied by activation of the CXC chemokine ligand 16 (CXCL16) pathway. In the in vitro study, we treated HK-2 cells with IL-1ß (5 ng/mL) and high glucose (30 mmol/L). IL-1ß treatment increased cholesterol accumulation in HK-2 cells, leading to greatly increased ROS production, ECM protein expression levels, which was accompanied by the upregulated expression levels of proteins in the CXCL16 pathway. In contrast, after CXCL16 in HK-2 cells was knocked down by siRNA, the IL-1ß-deteriorated changes were attenuated. In conclusion, inflammation accelerates renal tubulointerstitial lesions in mouse DN via increasing the activity of CXCL16 pathway.


Asunto(s)
Quimiocina CXCL16/metabolismo , Nefropatías Diabéticas/metabolismo , Mediadores de Inflamación/metabolismo , Inflamación/metabolismo , Túbulos Renales/metabolismo , Animales , Caseínas , Línea Celular , Quimiocina CXCL16/genética , Colesterol/metabolismo , Nefropatías Diabéticas/genética , Nefropatías Diabéticas/patología , Modelos Animales de Enfermedad , Proteínas de la Matriz Extracelular/metabolismo , Humanos , Inflamación/inducido químicamente , Inflamación/patología , Túbulos Renales/patología , Masculino , Ratones Endogámicos C57BL , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal , Factores de Tiempo
13.
BMC Nephrol ; 19(1): 192, 2018 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-30071823

RESUMEN

BACKGROUND: Increased plasma level of lipoprotein(a) (Lpa) is a risk factor of cardiovascular diseases. This study aimed to explore the role of Lpa in the progression of atherosclerosis in patients with end-stage renal disease (ESRD) and to investigate whether its potential mechanism is mediated by CXC chemokine ligand 16 (CXCL16) and low-density lipoprotein receptor (LDLr). METHODS: This is a retrospective clinical study. From January 2015 to April 2016, forty-six ESRD patients from Danyang First People's Hospital were investigated. The patients were grouped according to their plasma Lpa levels: control group (Lpa < 300 mg/l, n = 23) and high Lpa group (Lpa ≥ 300 mg/l, n = 23). ESRD Patients with acute infective diseases, cancer, and/or chronic active hepatitis were excluded. Biochemical indexes and lipid profiles of the patients were measured. Surgically removed tissues from the radial arteries of ESRD patients receiving arteriovenostomy were used for the preliminary evaluation of atherosclerosis. Haematoxylin-eosin (HE) and filipin staining were used to observe foam cell formation. Protein expression levels of Lpa, CXCL16, and LDLr were detected by immunohistochemistry staining and immunofluorescent staining. RESULTS: There was more foam cell formation and cholesterol accumulation in the radial arteries of the high Lpa group than in those of the control group. Furthermore, the expression levels of Lpa, CXCL16, and LDLr were significantly increased in the radial arteries of the high Lpa group. Correlation analyses showed that the protein expression levels of Lpa (r = 0.72, P < 0.01), LDLr (r = 0.54, P < 0.01), and CXCL16 (r = 0.6, P < 0.01) in the radial arteries of ESRD patients were positively correlated with the plasma Lpa levels. Further analyses showed that the co-expression of Lpa with LDLr or CXCL16 was increased in the high Lpa group. CONCLUSIONS: High plasma Lpa levels accelerated the progression of atherosclerosis in ESRD through inducing Lpa accumulation in the arteries, which was associated with LDLr and CXCL16. These two lipoproteins could both be major lipoprotein components that regulate the entry of Lpa into arterial cells.


Asunto(s)
Aterosclerosis/sangre , Aterosclerosis/diagnóstico , Progresión de la Enfermedad , Fallo Renal Crónico/sangre , Fallo Renal Crónico/diagnóstico , Lipoproteína(a)/sangre , Adulto , Anciano , Biomarcadores/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Estudios Retrospectivos
14.
Nurs Ethics ; 25(6): 734-745, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27682425

RESUMEN

BACKGROUND: Moral distress occurs when nurses experience ethical dilemmas. Issues related to these dilemmas are addressed in some nursing education courses. Nurses' reaction to dilemma such as moral distress is relatively less noticed. OBJECTIVE: This study aimed to identify and describe the various types of perceptions of moral distress exhibited by nurses. RESEARCH DESIGN: This study applied Q methodology to explore the perspectives of nurses regarding moral distress. Data were collected in two stages. First, in-depth interviews were conducted to collect nurses' opinions. Sentences that best fit the concepts of moral distress were extracted for the construction of Q statements. Second, nurses subjectively ranked these Q statements so that the relevant severity of moral distress could be determined using Q sorts. The study participants were nurses at a regional teaching hospital in northeast Taiwan. A total of 60 participants were invited to rank 40 moral distress Q statements. Ethical considerations: The study protocol was approved by the institutional review board of National Yang-Ming University Hospital. Only the participants who signed an informed consent form participated in the study. The respondents' right to withdraw from the study was respected. FINDINGS: Five types of responses were identified regarding the nurses' perspectives. These types were "conflict with personal values," "excessive of workload," "curbing of autonomy," "constraint engendered by organizational norms," and "self-expectation frustration." CONCLUSION: The findings regarding nurses' experiences of moral distress can be used to construct multifaceted policies and solutions and to incorporate ethical education in training programs.


Asunto(s)
Actitud del Personal de Salud , Ética en Enfermería , Principios Morales , Personal de Enfermería en Hospital/psicología , Estrés Psicológico/psicología , Adulto , Femenino , Hospitales de Enseñanza , Humanos , Personal de Enfermería en Hospital/estadística & datos numéricos , Investigación Cualitativa , Taiwán
15.
Faraday Discuss ; 197: 207-224, 2017 04 28.
Artículo en Inglés | MEDLINE | ID: mdl-28184397

RESUMEN

Various carbonaceous species were controllably deposited on Co/Al2O3 catalysts using ethylene as carbon source during the activation process for Fischer-Tropsch synthesis (FTS). Atomic, polymeric and graphitic carbon were distinguished by Raman spectroscopy, thermoanalysis and temperature programmed hydrogenation. Significant changes occurred in both the catalytic activity and selectivity toward hydrocarbon products after ethylene treatment. The activity decreased along with an increase in CH4 selectivity, at the expense of a remarkable decrease of heavy hydrocarbon production, resulting in enhanced selectivity for the gasoline fraction. In situ XPS experiments show the possible electron transfer from cobalt to carbon and the blockage of metallic cobalt sites, which is responsible for the deactivation of the catalyst. DFT calculations reveal that the activation barrier (Ea) of methane formation decreases by 0.61 eV on the carbon-absorbed Co(111) surface, whereas the Ea of the CH + CH coupling reaction changes unnoticeably. Hydrogenation of CHx to methane becomes the preferable route among the elementary reactions on the Co(111) surface, leading to dramatic changes in the product distribution. Detailed coke-induced deactivation mechanisms of Co-based catalysts during FTS are discussed.

16.
Sheng Li Xue Bao ; 68(2): 179-84, 2016 Apr 25.
Artículo en Zh | MEDLINE | ID: mdl-27108905

RESUMEN

The aim of the present study was to develop three-dimensional (3D) culture model, a more pathologically relevant model, of human breast cancer for drug resistance study. MCF-7 cells were embedded within collagen gel to establish 3D culture model. Cellular morphology was observed using Carmine and HE staining. Cell proliferation was evaluated by CCK-8 assay, and cell activity was detected by Live/Dead staining kit. Drug sensitivities of the 3D culture to doxorubicin, carboplatin, 5-fluorouracil were assayed and compared with those of monolayer (2D) culture. In addition, the levels of drug resistance-related genes P-glycoprotein (P-gp), mrp2 mRNA expressions were detected by real time RT-PCR. Expression level of P-gp protein was detected by Western blot. The results showed that MCF-7 cells in 3D culture formed a number of cell aggregates, and most of them displayed good cell viability. The IC50 values of doxorubicin, carboplatin, 5-fluorouracil were all increased significantly in 3D culture compared with those in 2D culture. Moreover, compared with MCF-7 cells in 2D culture, the cells in 3D culture showed increased mRNA levels of P-gp and mrp2, as well as up-regulated protein expression of P-gp. These results suggest that in vitro collagen-embedded culture system of human breast cancer cells represents an improved pathologically relevant 3D microenvironment for breast cancer cells, providing a robust tool to explore the mechanism of drug resistance of cancer cells.


Asunto(s)
Neoplasias de la Mama , Técnicas de Cultivo de Célula , Resistencia a Antineoplásicos , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP , Proliferación Celular , Supervivencia Celular , Doxorrubicina , Humanos , Células MCF-7
17.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 38(4): 464-9, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27594162

RESUMEN

Cells secrete around 30- 100 nm membrane-enclosed vesicles that are released into the extracellular spaceis termed exosomes(EXs). EXs widely present in body fluids and incorporated proteins,nucleic acids that reflect the physiological state of their cells of origin and they may play an important role in cell-to-cell communication in various physiological and disease processes. In this article we review the recent basic and clinical studies in urinary EXs in renal diseases,focusing on their biological characteristics and potential roles as new biological markers,intervention treatment goals,and targeted therapy vectors in renal diseases.However,some issues still exist;in particular,the clinical application of EXs as a liquid biopsy technique warrants further investigations.


Asunto(s)
Biomarcadores/orina , Exosomas , Enfermedades Renales/diagnóstico , Comunicación Celular , Humanos
18.
Ann Bot ; 115(2): 179-86, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25471098

RESUMEN

BACKGROUND AND AIMS: Although hybridization can play a positive role in plant evolution, it has been shown that excessive unidirectional hybridization can result in replacement of a species' gene pool, and even the extinction of rare species via genetic assimilation. This study examines levels of introgression between the common Saxifraga spathularis and its rarer congener S. hirsuta, which have been observed to hybridize in the wild where they occur sympatrically. METHODS: Seven species-specific single nucleotide polymorphisms (SNPs) were analysed in 1025 plants representing both species and their hybrid, S. × polita, from 29 sites across their ranges in Ireland. In addition, species distribution modelling was carried out to determine whether the relative abundance of the two parental species is likely to change under future climate scenarios. KEY RESULTS: Saxifraga spathularis individuals tended to be genetically pure, exhibiting little or no introgression from S. hirsuta, but significant levels of introgression of S. spathularis alleles into S. hirsuta were observed, indicating that populations exhibiting S. hirsuta morphology are more like a hybrid swarm, consisting of backcrosses and F2s. Populations of the hybrid, S. × polita, were generally comprised of F1s or F2s, with some evidence of backcrossing. Species distribution modelling under projected future climate scenarios indicated an increase in suitable habitats for both parental species. CONCLUSIONS: Levels of introgression observed in this study in both S. spathularis and S. hirsuta would appear to be correlated with the relative abundance of the species. Significant introgression of S. spathularis alleles was detected in the majority of the S. hirsuta populations analysed and, consequently, ongoing introgression would appear to represent a threat to the genetic integrity of S. hirsuta, particularly in areas where the species exists sympatrically with its congener and where it is greatly outnumbered.


Asunto(s)
Hibridación Genética , Endogamia , Polimorfismo de Nucleótido Simple , Saxifragaceae/clasificación , Saxifragaceae/genética , Ecosistema , Irlanda , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , Especificidad de la Especie , Simpatría
19.
ACS Appl Mater Interfaces ; 16(15): 19730-19741, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38591140

RESUMEN

Metal-organic framework materials can be converted into carbon-based nanoporous materials by pyrolysis, which have a wide range of applications in energy storage. Here, we design special interface engineering to combine the carbon skeleton and nitrogen-doped carbon nanotubes (CNTs) with the transition metal compounds (TMCs) well, which mitigates the bulk effect of the TMCs and improves the conductivity of the electrodes. Zeolitic imidazolate framework-67 is used as a precursor to form a carbon skeleton and a large number of nitrogen-doped CNTs by pyrolysis followed by the in situ formation of Co3O4 and CoS2, and finally, Co3O4@CNTs and CoS2@CNTs are synthesized. The obtained anode electrodes exhibit a long cycle life and high-rate properties. In lithium-ion batteries (LIBs), Co3O4@CNTs have a high capacity of 581 mAh g-1 at a high current of 5 A g-1, and their reversible capacity is still 1037.6 mAh g-1 after 200 cycles at 1 A g-1. In sodium-ion batteries (SIBs), CoS2@CNTs have a capacity of 859.9 mAh g-1 at 0.1 A g-1 and can be retained at 801.2 mAh g-1 after 50 cycles. The unique interface engineering and excellent electrochemical properties make them ideal anode materials for high-rate, long-life LIBs and SIBs.

20.
Adv Mater ; 35(12): e2204286, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36111553

RESUMEN

Metasurface polarization optics that consist of 2D array of birefringent nano-antennas have proven remarkable capabilities to generate and manipulate vectorial fields with subwavelength resolution and high efficiency. Integrating this new type of metasurface with the standard vertical cavity surface-emitting laser (VCSEL) platform enables an ultracompact and powerful solution to control both phase and polarization properties of the laser on a chip, which allows to structure a VCSEL into vector beams with on-demand wavefronts. Here, this concept is demonstrated by directly generating versatile vector beams from commercially available VCSELs through on-chip integration of high-index dielectric metasurfaces. Experimentally, the versatility of the approach for the development of vectorial VCSELs are validated by implementing a variety of functionalities, including directional emission of multibeam with specified polarizations, vectorial holographic display, and vector vortex beams generations. Notably, the proposed vectorial VCSELs integrated with a single layer of beam shaping metasurface bypass the requirements of multiple cascaded optical components, and thus have the potential to promote the advancements of ultracompact, lightweight, and scalable vector beams sources, enriching and expanding the applications of VCSELs in optical communications, laser manipulation and processing, information encryption, and quantum optics.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA