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1.
Zhonghua Fu Chan Ke Za Zhi ; 56(6): 425-433, 2021 Jun 25.
Artículo en Chino | MEDLINE | ID: mdl-34154318

RESUMEN

Objective: To investigate the differential expression of long non-coding RNA (lncRNA) in placental tissues of women with preeclampsia (PE) and the effect of MIR210HG on the biological function of HTR8/SVneo cells. Methods: A total of 39 cases of PE women (PE group) and 39 cases of normal pregnant women (CTL group) admitted to the Affiliated Hospital of Qingdao University from July 2018 to July 2019 were collected. (1) Transcriptome sequencing (RNA-seq) was used to analyze the differentially expressed lncRNAs in the placental tissues of the two groups. (2) The expression level of MIR210HG, one of the differentially expressed lncRNAs, in the placental tissues of the two groups was detected by real-time quantitative PCR. And the correlations between the expression level of MIR210HG and systolic blood pressure, diastolic blood pressure and neonatal birth weight were analyzed. (3) The constructed small interfering RNA and negative control (NC) RNA were transfected into the HTR8/SVneo cells. The cells were divided into MIR210HG knockdown (KD) group and NC group. The effects of living cell counting (CCK-8) and transwell assay on the proliferation and migration of HTR8/SVneo cells were detected. (4) RNA interacting with MIR210HG was predicted using the Encyclopedia of RNA Interactomes (ENCORI) database. Gene Ontology (GO) functional annotation, Kyoto Encyclopedia of Gene and Genomes (KEGG) and BioCarta pathway enrichment analysis were performed. Results: (1) A total of 26 significantly differentially expressed lncRNAs were found by RNA-seq, among which 21 lncRNAs were up-regulated and 5 lncRNAs were down-regulated. (2) The relative expression level of MIR210HG in the PE group was significantly higher than that in the CTL group (9.30±1.90 and 1.10±0.20, respectively; t=4.425, P<0.01). The relative expression level of MIR210HG had positive linear correlation with systolic blood pressure (r2=0.234, P<0.05) and diastolic blood pressure (r2=0.190, P<0.05), but had a negative linear correlation with newborn birth weight (r2=0.157, P<0.05). (3) Compared with the NC group, the proliferation and migration ability of HTR8/SVneo cells in the KD group were increased (all P<0.05). (4) A total of 38 RNAs that might interact with MIR210HG were predicted by ENCORI database. GO functional annotation analysis showed that MIR210HG might be involved in the functions of 27 pathways, including the regulation of production of molecular mediator of immune response, etc; KEGG pathway analysis showed that MIR210HG might be involved in the function of 8 pathways including allograft rejection, etc; Biocarta pathway analysis showed that MIR210HG may be involved in the functions of 8 pathways, including the eukaryotic initiation factor (eIF) pathway, etc. Conclusion: The expression of MIR210HG is up-regulated in the placental tissue of PE women, and MIR210HG might be a regulator of the biological behavior of trophoblast cells.


Asunto(s)
Placenta , Preeclampsia , ARN Largo no Codificante , Femenino , Humanos , Recién Nacido , Preeclampsia/genética , Embarazo , ARN Largo no Codificante/genética , ARN Interferente Pequeño , Trofoblastos
2.
J Adv Model Earth Syst ; 12(4): e2019MS001770, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32714492

RESUMEN

In China, irrigation is widespread in 40.7% cropland to sustain crop yields. By its action on water cycle, irrigation affects water resources and local climate. In this study, a new irrigation module, including flood and paddy irrigation technologies, was developed in the ORCHIDEE-CROP land surface model which describes crop phenology and growth in order to estimate irrigation demands over China from 1982 to 2014. Three simulations were performed including NI (no irrigation), IR (with irrigation limited by local water resources), and FI (with irrigation demand fulfilled). Observations and census data were used to validate the simulations. Results showed that the estimated irrigation water withdrawal ( W ) based on IR and FI scenarios bracket statistical W with fair spatial agreements ( r = 0 . 68 ± 0 . 07 ; p < 0 . 01 ). Improving irrigation efficiency was found to be the dominant factor leading to the observed W decrease. By comparing simulated total water storage (TWS) with GRACE observations, we found that simulated TWS with irrigation well explained the TWS variation over China. However, our simulation overestimated the seasonality of TWS in the Yangtze River Basin due to ignoring regulation of artificial reservoirs. The observed TWS decrease in the Yellow River Basin caused by groundwater depletion was not totally captured in our simulation, but it can be inferred by combining simulated TWS with census data. Moreover, we demonstrated that land use change tended to drive W locally but had little effect on total W over China due to water resources limitation.

3.
Nature ; 568(7751): 221-225, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30944480

RESUMEN

The global land and ocean carbon sinks have increased proportionally with increasing carbon dioxide emissions during the past decades1. It is thought that Northern Hemisphere lands make a dominant contribution to the global land carbon sink2-7; however, the long-term trend of the northern land sink remains uncertain. Here, using measurements of the interhemispheric gradient of atmospheric carbon dioxide from 1958 to 2016, we show that the northern land sink remained stable between the 1960s and the late 1980s, then increased by 0.5 ± 0.4 petagrams of carbon per year during the 1990s and by 0.6 ± 0.5 petagrams of carbon per year during the 2000s. The increase of the northern land sink in the 1990s accounts for 65% of the increase in the global land carbon flux during that period. The subsequent increase in the 2000s is larger than the increase in the global land carbon flux, suggesting a coincident decrease of carbon uptake in the Southern Hemisphere. Comparison of our findings with the simulations of an ensemble of terrestrial carbon models5,8 over the same period suggests that the decadal change in the northern land sink between the 1960s and the 1990s can be explained by a combination of increasing concentrations of atmospheric carbon dioxide, climate variability and changes in land cover. However, the increase during the 2000s is underestimated by all models, which suggests the need for improved consideration of changes in drivers such as nitrogen deposition, diffuse light and land-use change. Overall, our findings underscore the importance of Northern Hemispheric land as a carbon sink.


Asunto(s)
Dióxido de Carbono/análisis , Dióxido de Carbono/historia , Secuestro de Carbono , Mapeo Geográfico , Sedimentos Geológicos/química , Atmósfera/química , Carbono/química , Dióxido de Carbono/química , China , Materiales de Construcción/análisis , Bosques , Combustibles Fósiles/análisis , Historia del Siglo XX , Historia del Siglo XXI , Modelos Lineales , Modelos Teóricos , Nitrógeno/química , Siberia , Incertidumbre
4.
Meat Sci ; 137: 258-264, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29245028

RESUMEN

The fat quality is an important aspect, especially for Wagyu beef. A handheld fiber-optic near-infrared spectrometer for on-site evaluation of beef fat quality was developed, and the interactance spectra of the intermuscular fat from 833 Wagyu carcasses at 12 markets were measured. The calibration model was transferred to five slave instruments using twenty-six block samples. The performance of one slave instrument was verified at five meat markets (n=360). The coefficients of determination of the slave instrument for monounsaturated, oleic, and saturated fatty acid compositions determined by gas chromatography and near-infrared measurements were 0.69, 0.64, and 0.67, respectively. The standard error of prediction for the slave instrument was approximately 2%. The fiber-optic near-infrared spectrometers were highly accurate in the fat quality evaluation of Wagyu carcasses based on monounsaturated, oleic, and saturated fatty acid composition with easy calibration model transfer.


Asunto(s)
Tejido Adiposo/química , Bovinos , Ácidos Grasos/análisis , Carne Roja/análisis , Espectroscopía Infrarroja Corta/métodos , Animales , Cromatografía de Gases , Femenino , Masculino , Carne Roja/normas
5.
Sci Rep ; 7(1): 9632, 2017 08 29.
Artículo en Inglés | MEDLINE | ID: mdl-28851977

RESUMEN

Concentrations of atmospheric carbon dioxide (CO2) have continued to increase whereas atmospheric deposition of sulphur and nitrogen has declined in Europe and the USA during recent decades. Using time series of flux observations from 23 forests distributed throughout Europe and the USA, and generalised mixed models, we found that forest-level net ecosystem production and gross primary production have increased by 1% annually from 1995 to 2011. Statistical models indicated that increasing atmospheric CO2 was the most important factor driving the increasing strength of carbon sinks in these forests. We also found that the reduction of sulphur deposition in Europe and the USA lead to higher recovery in ecosystem respiration than in gross primary production, thus limiting the increase of carbon sequestration. By contrast, trends in climate and nitrogen deposition did not significantly contribute to changing carbon fluxes during the studied period. Our findings support the hypothesis of a general CO2-fertilization effect on vegetation growth and suggest that, so far unknown, sulphur deposition plays a significant role in the carbon balance of forests in industrialized regions. Our results show the need to include the effects of changing atmospheric composition, beyond CO2, to assess future dynamics of carbon-climate feedbacks not currently considered in earth system/climate modelling.

6.
Zhonghua Wai Ke Za Zhi ; 55(6): 410-415, 2017 Jun 01.
Artículo en Chino | MEDLINE | ID: mdl-28592072

RESUMEN

Objective: To investigate the methods and short-time clinical results of reconstruction of Paprosky type Ⅲ acetabulum bone defects by using tantalum augments. Methods: A total of 17 patients (17 hips) with Paprosky type Ⅲ acetabulum bone defects, treated with tantalum augments in revision of total hip arthroplasty at Department of Orthopedics Surgery in General Hospital of Chinese People's Liberation Army were retrospectively analyzed from March 2014 to May 2016.There were 6 males and 11 females aged from 23 to 74 years with an average of (50.2±16.3) years. Tantalum augments or TM-Cup augment (the cup-on-cup technique) were used to reconstruct the defects.The TM-Cup augment was the tantalum revision cup which was removed titanium ring. The cup-on-cup technique combined TM-Cup augment and biological acetabulum cup. Augments were served as the nonresorptive structural allograft in revision of total hip arthroplasty. Harris hip score was used to evaluate clinical effects. The vertical position of the rotation center was measured and analyzed. Radiographic assessments of the acetabular components were performed by DeLee-Charnley and the Anderson criteria and recorded postoperative complications. Results: All the patients were followed up from 3 to 29 months with an average of (16.2±5.4) months, tantalum augments and biological acetabulum cup were used in 13 patients, the TM-Cup augment and biological acetabulum cup were used in 4 patients. At the time of the latest follow-up, the mean Harris hip score increased compared to preoperatively (86.8±8.3 vs. 30.0±12.0) (t=12.78, P<0.01), the average vertical location of the center of rotation was decreased ((25.3±9.8) mm vs.(47.6±10.5)) mm (t=4.95, P<0.01). All the tantalum augments and biological acetabulum cups were stable, there were no infection, dislocation and other complications. Conclusions: The use of tantalum augments could be considered as an effective management of Paprosky type Ⅲ defects providing good clinical and radiographic outcomes in the short term.The cup-on-cup technique which was used in reconstruction of severe superior-invagination acetabular bone defects and restoration relatively normal center of rotation had special application value.


Asunto(s)
Acetábulo/cirugía , Artroplastia de Reemplazo de Cadera , Prótesis de Cadera , Adulto , Anciano , Femenino , Humanos , Luxaciones Articulares , Masculino , Metales , Persona de Mediana Edad , Complicaciones Posoperatorias , Falla de Prótesis , Reoperación , Estudios Retrospectivos , Rotación , Tantalio , Trasplante Homólogo
7.
Ecology ; 97(8): 1961-1969, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27859198

RESUMEN

The timing of the fruit-set stage (i.e., start and end of fruit set) is crucial in a plant's life cycle, but its response to temperature change is still unclear. We investigated the timing of seven phenological events, including fruit-set dates during 3 yr for six alpine plants transplanted to warmer (approximately +3.5°C in soils) and cooler (approximately -3.5°C in soils) locations along an altitudinal gradient in the Tibetan area. We found that fruit-set dates remained relatively stable under both warming and cooling during the 3-yr transplant experiment. Three earlier phenological events (emergence of first leaf, first bud set, and first flowering) and two later phenological events (first leaf coloring and complete leaf coloring) were earlier by 4.8-8.2 d/°C and later by 3.2-7.1 d/°C in response to warming. Conversely, cooling delayed the three earlier events by 3.8-6.9 d/°C and advanced the two later events by 3.2-8.1 d/°C for all plant species. The timing of the first and/or last fruit-set dates, however, did not change significantly compared to earlier and later phenological events. Statistical analyses also showed that the dates of fruit set were not significantly correlated or had lower correlations with changes of soil temperature relative to the earlier and later phenological events. Alpine plants may thus acclimate to changes in temperature for their fruiting function by maintaining relatively stable timings of fruit set compared with other phenological events to maximize the success of seed maturation and dispersal in response to short-term warming or cooling.


Asunto(s)
Frutas , Temperatura , Cambio Climático , Frío , Ecología , Hojas de la Planta , Fenómenos Fisiológicos de las Plantas , Reproducción , Estaciones del Año
8.
Phys Rev E ; 94(2-1): 020602, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27627230

RESUMEN

Micron-sized colloidal spheres that are dispersed in an isotropic-nematic biphasic host suspension of charged rods (fd-virus particles) are shown to spontaneously form dimers, which exhibit a synchronized oscillatory motion. Dimer formation is not observed in the monophase of isotropic and nematic suspensions. The synchronized oscillations of dimers are connected to the inhomogeneous state of the host suspension of charged rods (fd viruses) where nematic domains are in coexistence with isotropic regions. The synchronization of oscillations occurs in bulk states, in the absence of an external field. With a low field strength of an applied electric field, the synchronization is rather reduced, but it recovers again when the field is turned off. In this Rapid Communication, we report this observation as an example of the strange attractor, occurring in the mixture of PS (polystyrene) dimers in an isotropic-nematic coexistence biphasic fd-virus network. Furthermore, we highlight that the synchronization of PS-dimer oscillations is the result of a global bifurcation diagram, driven by a delicate balance between the short-attractive "twisted" interaction of PS dimers and long-ranged electrostatic repulsive interactions of charged fd rods. The interest is then in the local enhancement of "twist-nematic" elasticity in reorientation of the dimer oscillations. An analysis of image-time correlations is provided with the data movies and Fourier transforms of averaged orientations for the synchronized oscillations of dimers in the biphasic I-N coexistence concentration of charged fd-virus suspensions.


Asunto(s)
Microesferas , Polímeros/química , Electricidad Estática , Movimiento (Física) , Poliestirenos/química , Suspensiones
10.
Nature ; 525(7568): 201-5, 2015 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-26331545

RESUMEN

The global extent and distribution of forest trees is central to our understanding of the terrestrial biosphere. We provide the first spatially continuous map of forest tree density at a global scale. This map reveals that the global number of trees is approximately 3.04 trillion, an order of magnitude higher than the previous estimate. Of these trees, approximately 1.39 trillion exist in tropical and subtropical forests, with 0.74 trillion in boreal regions and 0.61 trillion in temperate regions. Biome-level trends in tree density demonstrate the importance of climate and topography in controlling local tree densities at finer scales, as well as the overwhelming effect of humans across most of the world. Based on our projected tree densities, we estimate that over 15 billion trees are cut down each year, and the global number of trees has fallen by approximately 46% since the start of human civilization.


Asunto(s)
Bosques , Mapeo Geográfico , Árboles/crecimiento & desarrollo , Ecología/estadística & datos numéricos , Ecosistema , Agricultura Forestal/estadística & datos numéricos , Densidad de Población , Reproducibilidad de los Resultados
11.
Transplant Proc ; 46(2): 521-8, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24656003

RESUMEN

Long-term treatment with cyclosporine A (CsA) is associated with various types of complications; however, CsA-induced anemia has not been reported. The present study examined the impact of CsA on hematopoietic parameters and intrarenal expression of erythropoietin (EPO) and the EPO receptor (EPOR) in a rat model of chronic CsA nephrotoxicity. Sprague-Dawley rats were fed a low-salt diet (0.05% sodium) and were treated daily for 4 weeks with vehicle (olive oil 1 mL/kg subcutaneously) or CsA (15 mg/kg subcutaneously). The expression of EPO and EPOR was evaluated by immunohistochemistry and immunoblotting, and hematopoietic parameters were assessed by measuring blood hemoglobin and hematocrit levels, and these variables were compared between treatment groups. Renal function, oxidative stress, histopathology (tubulointerstitial fibrosis), apoptotic cell death, and expression of transforming growth factor ß-inducible gene-h3 (ßig-h3) were also compared between treatment groups. In kidneys from vehicle-treated rats, endogenous EPO and EPOR protein were expressed constitutively in the outer stripe of the outer medulla and the cortex. EPO protein expression decreased significantly in kidneys from CsA-treated rats. By contrast, EPOR expression was higher in kidneys from CsA-treated rats than in vehicle-treated rats. These changes were accompanied by decreases in serum hemoglobin and hematocrit levels and correlated with the number of cells positive for terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (r = -0.769, P = .003) and ßig-h3 protein expression (r = -0.910, P < .001). Long-term treatment with CsA suppresses renal endogenous EPO expression, resulting in anemia. Increases in apoptotic cell death and ßig-h3 expression are closely associated with inhibition of EPO expression in chronic CsA nephrotoxicity.


Asunto(s)
Ciclosporina/uso terapéutico , Eritropoyetina/metabolismo , Riñón/metabolismo , Receptores de Eritropoyetina/metabolismo , Animales , Etiquetado Corte-Fin in Situ , Masculino , Ratas , Ratas Sprague-Dawley
12.
Transplant Proc ; 45(8): 3127-34, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24157049

RESUMEN

BACKGROUND: L-carnitine has protective effects against various types of injury. This study was designed to evaluate the beneficial effects of L-carnitine on pancreatic and renal injuries caused by cyclosporine (CsA). METHODS: Rats maintained on a low sodium diet were given vehicle (olive oil, 1 mL/kg/d), CsA (15 mg/kg/d), L-carnitine (50 or 200 mg/kg/d), or a combination of CsA and L-carnitine for 4 weeks. The impact of L-carnitine on pancreatic injury was assessed by blood glucose levels, plasma insulin concentrations, and hemoglobulin A1c (HbA1c). In addition, the protective effects of L-carnitine against CsA-induced kidney injury were evaluated in terms of renal function, histopathology (inflammatory cell influx and tubulointerstitial fibrosis), oxidative stress (8-hydroxy 2'-deoxyguanosine, 8-OHdG), transforming growth factor-betal (TGF-ß1), apoptosis (caspase-3), and autophagy (LC3-II). RESULTS: CsA treatment caused diabetes, renal dysfunction, tubulointerstitial inflammation (ED-1-positive cells), and fibrosis, which were accompanied by an increase in 8-OHdG production and upregulation of TGF-ß1, caspase-3, and LC3-II. Concomitant administration of L-carnitine increased plasma insulin concentrations, decreasing plasma glucose and HbA1c levels. In the kidney, L-carnitine induced dose-dependent improvement of renal function, inflammation, and fibrosis in parallel with suppression of the expression of TGF-ß1 and 8-OHdG. Furthermore, the administration of L-carnitine at a high dose inhibited the expression of caspase-3 and LC3-II. CONCLUSION: These findings suggest that L-carnitine has a protective effect against CsA-induced pancreatic and renal injuries.


Asunto(s)
Carnitina/farmacología , Ciclosporina/antagonistas & inhibidores , Riñón/efectos de los fármacos , Páncreas/efectos de los fármacos , Animales , Western Blotting , Masculino , Ratas , Ratas Sprague-Dawley
13.
Transplant Proc ; 44(3): 642-5, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22483459

RESUMEN

We evaluated the protective effect of paricalcitol on cyclosporine (CsA)-induced renal injury using an experimental model of chronic CsA nephropathy. Paricalcitol (50 and 200 ng/kg/d) was concomitantly administered with CsA (15 mg/kg/d) for 28 days in rats. We assessed the effects of paricalcitol by measuring degree of the tubulointerstitial fibrosis (TIF) and inflammation, a profibrotic cytokine (ßig-h3), a proapoptotic gene (caspase-3), apoptotic cell death, and oxidative stress. The CsA-treated rats showed increased TIF and inflammatory cell infiltration, but paricalcitol treatment (200 ng/kg) significantly decreased those compared with the CsA-alone group. The expression of ßig-h3, a biologic marker of transforming growth factor ß1, which was increased in the CsA group, also decreased with paricalcitol treatment. The increased rates of excretion of urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and expression of tissue 8-OHdG produced by CsA treatment were significantly attenuated by paricalcitol treatment. The increased expression of caspase-3 and number of TUNEL-positive cells in the CsA group were decreased with concomitant paricalcitol treatment. The effect of paricalcitol was more evident high among the rather than low-dose cohort. In conclusion, paricalcitol showed antiinflammatory and antifibrotic effects. This finding may provide a rationale for use of paricalcitol in CsA-induced renal injury.


Asunto(s)
Ciclosporina/efectos adversos , Ergocalciferoles/uso terapéutico , Inmunosupresores/efectos adversos , Riñón/efectos de los fármacos , 8-Hidroxi-2'-Desoxicoguanosina , Animales , Apoptosis/efectos de los fármacos , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Relación Dosis-Respuesta a Droga , Ergocalciferoles/farmacología , Proteínas de la Matriz Extracelular/metabolismo , Inmunohistoquímica , Etiquetado Corte-Fin in Situ , Riñón/lesiones , Macrófagos/patología , Masculino , Estrés Oxidativo/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Factor de Crecimiento Transformador beta/metabolismo
14.
Ecol Lett ; 15(6): 520-6, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22472207

RESUMEN

Trees with sufficient nutrition are known to allocate carbon preferentially to aboveground plant parts. Our global study of 49 forests revealed an even more fundamental carbon allocation response to nutrient availability: forests with high-nutrient availability use 58 ± 3% (mean ± SE; 17 forests) of their photosynthates for plant biomass production (BP), while forests with low-nutrient availability only convert 42 ± 2% (mean ± SE; 19 forests) of annual photosynthates to biomass. This nutrient effect largely overshadows previously observed differences in carbon allocation patterns among climate zones, forest types and age classes. If forests with low-nutrient availability use 16 ± 4% less of their photosynthates for plant growth, what are these used for? Current knowledge suggests that lower BP per unit photosynthesis in forests with low- versus forests with high-nutrient availability reflects not merely an increase in plant respiration, but likely results from reduced carbon allocation to unaccounted components of net primary production, particularly root symbionts.


Asunto(s)
Biomasa , Ciclo del Carbono , Árboles/crecimiento & desarrollo , Procesos Autotróficos , Carbono/metabolismo , Respiración de la Célula , Clima , Agricultura Forestal , Fotosíntesis , Raíces de Plantas/microbiología , Árboles/metabolismo , Árboles/microbiología
15.
Nanotechnology ; 22(39): 395303, 2011 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-21896974

RESUMEN

A large number of silicon (Si) patterns consisting of nanopillars of varying diameter and pitch have been fabricated and further coated with diamond-like carbon (DLC) and perfluoropolyether (Z-DOL) films. The wetting behavior and nano-adhesion/friction of the patterns are investigated experimentally in relation to the nanostructures and the hydrophobicity of the materials. Measurements of water contact angle illustrate that the patterning-enhanced wettability of the Si flat surface, along with two distinct wettings which are in good agreement with the Wenzel and hemi-wicking states, depended on the value of the pitch-over-diameter ratio. In the case of the coated patterns, three wetting states are observed: the Cassie-Baxter, the Wenzel, and a transition from the Cassie-Baxter into the Wenzel, which varies with regard to the hydrophobic properties of the DLC and Z-DOL. In terms of tribological properties, it is demonstrated that a combination of the nanopatterns and the films is effective in reducing adhesive and frictional forces. In addition, the pitch and diameter of the patterns are found to significantly influence their adhesion/friction behaviors.


Asunto(s)
Carbono/química , Éteres/química , Fluorocarburos/química , Nanoestructuras/química , Silicio/química , Humectabilidad , Nanoestructuras/ultraestructura
16.
Philos Trans A Math Phys Eng Sci ; 369(1943): 2038-57, 2011 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-21502175

RESUMEN

The African continent contributes one of the largest uncertainties to the global CO(2) budget, because very few long-term measurements are carried out in this region. The contribution of Africa to the global carbon cycle is characterized by its low fossil fuel emissions, a rapidly increasing population causing cropland expansion, and degradation and deforestation risk to extensive dryland and savannah ecosystems and to tropical forests in Central Africa. A synthesis of the carbon balance of African ecosystems is provided at different scales, including observations of land-atmosphere CO(2) flux and soil carbon and biomass carbon stocks. A review of the most recent estimates of the net long-term carbon balance of African ecosystems is provided, including losses from fire disturbance, based upon observations, giving a sink of the order of 0.2 Pg C yr(-1) with a large uncertainty around this number. By comparison, fossil fuel emissions are only of the order of 0.2 Pg C yr(-1) and land-use emissions are of the order of 0.24 Pg C yr(-1). The sources of year-to-year variations in the ecosystem carbon-balance are also discussed. Recommendations for the deployment of a coordinated carbon-monitoring system for African ecosystems are given.


Asunto(s)
Ciclo del Carbono , Cambio Climático , África , Biomasa , Ecosistema , Suelo/análisis , Factores de Tiempo , Árboles
17.
Oncogene ; 29(21): 3124-33, 2010 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-20305697

RESUMEN

The epithelial to mesenchymal transition (EMT) that occurs during embryonic development has begun to attract attention as a potential mechanism for tumor cell metastasis. Snail is a well-known Zn-finger transcription factor that promotes EMT by repressing E-cadherin expression. It is known that Snail is phosphorylated by GSK3beta and degraded by beta-TrCP-mediated ubiquitination. Here we described another protein kinase, CK1, whose phosphorylation of Snail is required for the subsequent GSK3beta phosphorylation. Specific inhibition or depletion of CK1varepsilon inhibits the phosphorylation and degradation of Snail and promotes cell migration, suggesting a central role of CK1varepsilon in the EMT process. Furthermore, our study uncovered distinct roles and steps of Snail phosphorylation by CK1varepsilon and GSK3beta. Taken together, we identified CK1varepsilon as a new component of the Snail-mediated EMT process, providing insight into the mechanism of human cancer metastasis.


Asunto(s)
Glucógeno Sintasa Quinasa 3/metabolismo , Factores de Transcripción/metabolismo , Sitios de Unión , Creatina Quinasa/metabolismo , Glutatión Transferasa/metabolismo , Glucógeno Sintasa Quinasa 3 beta , Humanos , Isoenzimas/metabolismo , Cinética , Fosforilación , Fosfoserina/metabolismo , ARN Interferente Pequeño/metabolismo , Factores de Transcripción de la Familia Snail , Especificidad por Sustrato , Proteínas con Repetición de beta-Transducina/metabolismo
18.
Am J Transplant ; 9(9): 2024-33, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19624561

RESUMEN

This study was performed to investigate the effect of sirolimus (SRL) on cyclosporine (CsA)-induced pancreatic islet dysfunction in rats. Three separate studies were performed. First, diabetogenic effect of SRL was evaluated with three different doses (0.15, 0.3 and 0.6 mg/kg). Second, rats were treated with SRL (0.3 mg/kg) with or without CsA (15 mg/kg) for 4 weeks. Third, rats were treated with CsA for 4 weeks, and then switched to SRL for 4 weeks. The effect of SRL on CsA-induced pancreatic islet dysfunction was evaluated by an intraperitoneal glucose tolerance test, plasma insulin concentration, HbA1c level, HOMA-R index, immunohistochemistry of insulin and pancreatic beta islet cell mass. The SRL treatment increased blood glucose concentration in a dose-dependent manner. The combined treatment with SRL and CsA increased blood glucose concentration, Hemoglobin A1c (HbA1c) level, HOMA-R [fasting insulin (mU/mL) x fasting glucose (mmol/L)]/22.5] index and decreased plasma insulin concentration, immunoreactivity of insulin and pancreatic beta islet cell mass compared with rats treated with CsA. CsA withdrawal for 4 weeks improved pancreatic beta-cell function and structure. However, conversion from CsA to SRL further increased blood glucose levels compared with the rats converted from vehicle to SRL. The results of our study demonstrate that SRL is diabetogenic and aggravates CsA-induced pancreatic islet dysfunction.


Asunto(s)
Ciclosporina/efectos adversos , Diabetes Mellitus Experimental/tratamiento farmacológico , Islotes Pancreáticos/efectos de los fármacos , Sirolimus/farmacología , 8-Hidroxi-2'-Desoxicoguanosina , Animales , Glucemia/metabolismo , Desoxiguanosina/análogos & derivados , Desoxiguanosina/farmacología , Diabetes Mellitus Experimental/patología , Relación Dosis-Respuesta a Droga , Hemoglobina Glucada/metabolismo , Inmunohistoquímica/métodos , Inmunosupresores/efectos adversos , Insulina/sangre , Masculino , Ratas , Ratas Sprague-Dawley
19.
Anal Biochem ; 297(2): 137-43, 2001 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-11673880

RESUMEN

The common mobile phase hexane/isopropanol/water used for separation of phospholipids on high-performance liquid chromatography silica columns poses several problems, such as incomplete separation and rapid column deterioration. By inclusion of 5 mM ammonium sulfate in the aqueous phase, we were able to substantially improve the chromatographic resolution and obtain complete separation of phosphatidylcholine, phosphatidylethanolamine, lysophosphatidylcholine, lysophosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, cardiolipin, phosphatidylglycerol, and sphingomyelin. In addition, ammonium sulfate prevented column degeneration and greatly improved reproducibility. A new quantitation method for alkenylacyl, alkylacyl, and diacyl forms of phospholipids was also developed based on derivatization with [(3)H]acetic anhydride. Separation and quantitation of the radioactive acetyl diradylglycerols were performed by straight-phase HPLC coupled to a radioactive flow detector and enabled detection of the various ether analogues at the picomole level with high reproducibility. The described methods are mild and nondestructive and can therefore be easily combined with analysis of either molecular species or fatty acid and aldehyde composition of the individual phospholipids.


Asunto(s)
Aldehídos/análisis , Química Encefálica , Cromatografía Líquida de Alta Presión/métodos , Ácidos Grasos/análisis , Fosfolípidos/aislamiento & purificación , Animales , Diglicéridos/aislamiento & purificación , Éteres/análisis , Humanos , Hígado/química , Ratones , Miocardio/química , Fosfolípidos/clasificación , Ratas
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