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1.
Ann Bot ; 124(4): 531-542, 2019 10 29.
Artículo en Inglés | MEDLINE | ID: mdl-30759181

RESUMEN

BACKGROUND AND AIMS: Bioenergy is central for the future energy mix to mitigate climate change impacts; however, its intricate link with the water cycle calls for an evaluation of the carbon-water nexus in biomass production. The great challenge is to optimize trade-offs between carbon harvest and water use by choosing cultivars that combine low water use with high productivity. METHODS: Regional scenarios were simulated over a range of willow genotype × environment interactions for the major UK soil × climate variations with the process-based model LUCASS. Soil available water capacity (SAWC) ranged from 51 to 251 mm and weather represented the north-west (wet, cool), north-east (dry, cool), south-west (wet, warm) and south-east (dry, warm) of the UK. Scenario simulations were evaluated for small/open narrow-leaf (NL) versus large/closed broad-leaf (BL) willow canopy phenotypes using baseline (1965-89) and warmer recent (1990-2014) weather data. KEY RESULTS: The low productivity under baseline climate in the north could be compensated by choosing BL cultivars (e.g. 'Endurance'). Recent warmer climate increased average productivity by 0.5-2.5 t ha-1, especially in the north. The modern NL cultivar 'Resolution' had the smallest and most efficient water use. On marginal soils (SAWC <100 mm), yields remained below an economic threshold of 9 t ha-1 more frequently under baseline than recent climate. In the drought-prone south-east, 'Endurance' yielded less than 'Resolution', which consumed on average 17 mm year-1 less water. Assuming a planting area of 10 000 ha, in droughty years between 1.3 and 4.5 × 106 m3 of water could be saved, with a small yield penalty, for 'Resolution'. CONCLUSIONS: With an increase in air temperature and occasional water scarcities expected with climate change, high-yielding NL cultivars should be the preferred choice for sustainable use of marginal lands and reduced competition with agricultural food crops.


Asunto(s)
Salix , Agricultura , Cambio Climático , Fenotipo , Agua
2.
Sci Total Environ ; 900: 166390, 2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-37597557

RESUMEN

Reductions in CO2 emissions are essential to support the UK in achieving its net zero policy objective by around mid-century. Both changing climate and land use change (LUC) offer an opportunity to deploy suitable bioenergy crops strategically to enhance energy production and C sequestration to help deliver net zero through capturing atmospheric CO2. Against this background, we applied process-based models to evaluate the extent of net primary productivity (NPP) losses/gains associated with perennial bioenergy crops and to assess their C sequestration potential under changing climate in the upper River Taw observatory catchment in southwest England. In so doing, we also determined whether LUC from permanent grassland to perennial bioenergy crops, considered in this study, can increase the production and C sequestration potential in the study area. The results show that a warming climate positively impacts the production of all crops considered (permanent grassland, Miscanthus and two cultivars of short rotation coppice (SRC) willow). Overall, Miscanthus provides higher aboveground biomass for energy compared to willow and grassland whereas the broadleaf willow cultivar 'Endurance' is best suited, among all crops considered, for C sequestration in this environment, and more so in the changing climate. In warmer lowlands, LUC from permanent grassland to Miscanthus and in cooler uplands from permanent grassland to 'Endurance', enhances NPP. Colder areas are predicted to benefit more from changing climate in terms of above and belowground biomass for both Miscanthus and willow. The study shows that the above LUC can help augment non-fossil energy production and increase C sequestration potential if C losses from land conversion do not exceed the benefits from LUC. In the wake of a changing climate, aboveground biomass for bioenergy and belowground biomass to enhance carbon sequestration can be managed by the careful selection of bioenergy crops and targeted deployment within certain climatic zones.


Asunto(s)
Dióxido de Carbono , Salix , Secuestro de Carbono , Ríos , Producción de Cultivos , Productos Agrícolas , Inglaterra , Poaceae , Cambio Climático
3.
Grass Forage Sci ; 78(1): 50-63, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38516168

RESUMEN

Each new generation of grassland managers could benefit from an improved understanding of how modification of nitrogen application and harvest dates in response to different weather and soil conditions will affect grass yields and quality. The purpose of this study was to develop a freely available grass yield simulation model, validated for England and Wales, and to examine its strengths and weaknesses as a teaching tool for improving grass management. The model, called LINGRA-N-Plus, was implemented in a Microsoft Excel spreadsheet and iteratively evaluated by students and practitioners (farmers, consultants, and researchers) in a series of workshops across the UK over 2 years. The iterative feedback led to the addition of new algorithms, an improved user interface, and the development of a teaching guide. The students and practitioners identified the ease of use and the capacity to understand, visualize and evaluate how decisions, such as variation of cutting intervals, affect grass yields as strengths of the model. We propose that an effective teaching tool must achieve an appropriate balance between being sufficiently detailed to demonstrate the major relationships (e.g., the effect of nitrogen on grass yields) whilst not becoming so complex that the relationships become incomprehensible. We observed that improving the user-interface allowed us to extend the scope of the model without reducing the level of comprehension. The students appeared to be interested in the explanatory nature of the model whilst the practitioners were more interested in the application of a validated model to enhance their decision making.

4.
Rofo ; 194(6): 634-643, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35081648

RESUMEN

PURPOSE: Report of experience from a single institution in treating postoperative lymphatic leakage (PLL) applying conventional transpedal lymphangiography (TL). MATERIALS AND METHODS: 453 patients with the initial diagnosis of PLL receiving TL between 03/1993 and 09/2018 were identified in the database. Only patients with confirmed PLL were included in the study. The technical success, safety, and treatment success of TL were evaluated. Independent predictors of TL treatment failure were examined using univariate and multivariate logistic regression analysis. RESULTS: 355 consecutive patients (218 men, 137 women; median age of 62 years) who underwent TL for PLL (e. g., chylothorax) after ineffective conservative treatment were included. The median time between causal surgery and TL was 27 days. The median technical success rate of TL was 88.5 %, with a median volume of Lipiodol of 10.0 ml. No complication of TL was recorded. Three groups were defined according to the different clinical courses: group A (41/355, 11.5 %) - TL with technical failure; group B (258/355, 72.7 %) - "therapeutic" TL alone with technical success; and group C (56/355, 15.8 %) - "diagnostic" TL with simultaneously invasive treatment (incl. surgical revision and percutaneous sclerotherapy). Treatment success rate and median time to treatment success were higher in group C than in group B, but without significant differences (64.3 % vs. 61.6 %, p = 0.710; six vs. five days, p = 0.065). Univariate and multivariate logistic regression analyses for group B confirmed drainage volume (> 500 ml/d) and Lipiodol extravasation as independent predictors of TL clinical failure (odds ratios [ORs] of 2.128 and 2.372 [p = 0.005 and p = 0.003, respectively]). CONCLUSION: TL is technically reliable, safe, and effective in treating PLL. When conservative treatment fails, TL can be regarded as the next treatment option. KEY POINTS: · TL is technically reliable, safe, and effective for treating PLL.. · When conservative treatment fails, TL can be regarded as the next treatment option.. · Drainage volume > 500 ml/day is an independent predictor of clinical failure after TL.. · Lipiodol extravasation is an independent predictor of clinical failure after TL.. CITATION FORMAT: · Pan F, Richter GM, Do TD et al. Treatment of Postoperative Lymphatic Leakage Applying Transpedal Lymphangiography - Experience in 355 Consecutive Patients. Fortschr Röntgenstr 2022; 194: 634 - 643.


Asunto(s)
Quilotórax , Linfografía , Quilotórax/diagnóstico por imagen , Quilotórax/terapia , Aceite Etiodizado , Femenino , Humanos , Sistema Linfático , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/diagnóstico por imagen , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/terapia , Estudios Retrospectivos , Resultado del Tratamiento
5.
Sci Total Environ ; 824: 153824, 2022 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-35182632

RESUMEN

Agriculture is challenged to produce healthy food and to contribute to cleaner energy whilst mitigating climate change and protecting ecosystems. To achieve this, policy-driven scenarios need to be evaluated with available data and models to explore trade-offs with robust accounting for the uncertainty in predictions. We developed a novel model ensemble using four complementary state-of-the-art agroecosystems models to explore the impacts of land management change. The ensemble was used to simulate key agricultural and environmental outputs under various scenarios for the upper River Taw observatory, UK. Scenarios assumed (i) reducing livestock production whilst simultaneously increasing the area of arable where it is feasible to cultivate (PG2A), (ii) reducing livestock production whilst simultaneously increasing bioenergy production in areas of the catchment that are amenable to growing bioenergy crops (PG2BE) and (iii) increasing both arable and bioenergy production (PG2A + BE). Our ensemble approach combined model uncertainty using the tower property of expectation and the law of total variance. Results show considerable uncertainty for predicted nutrient losses with different models partitioning the uncertainty into different pathways. Bioenergy crops were predicted to produce greatest yields from Miscanthus in lowland and from SRC-willow (cv. Endurance) in uplands. Each choice of management is associated with trade-offs; e.g. PG2A results in a significant increase of edible calories (6736 Mcal ha-1) but reduced soil C (-4.32 t C ha-1). Model ensembles in the agroecosystem context are difficult to implement due to challenges of model availability and input and output alignment. Despite these challenges, we show that ensemble modelling is a powerful approach for applications such as ours, offering benefits such as capturing structural as well as data uncertainty and allowing greater combinations of variables to be explored. Furthermore, the ensemble provides a robust means for combining uncertainty at different scales and enables us to identify weaknesses in system understanding.


Asunto(s)
Ecosistema , Ríos , Agricultura , Carbono , Conservación de los Recursos Naturales , Productos Agrícolas , Nutrientes , Reino Unido
6.
J Exp Bot ; 62(10): 3263-71, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21515638

RESUMEN

Growing crops for bioenergy or biofuels is increasingly viewed as conflicting with food production. However, energy use continues to rise and food production requires fuel inputs, which have increased with intensification. Focussing on the question of food or fuel is thus not helpful. The bigger, more pertinent, challenge is how the increasing demands for food and energy can be met in the future, particularly when water and land availability will be limited. Energy crop production systems differ greatly in environmental impact. The use of high-input food crops for liquid transport fuels (first-generation biofuels) needs to be phased out and replaced by the use of crop residues and low-input perennial crops (second/advanced-generation biofuels) with multiple environmental benefits. More research effort is needed to improve yields of biomass crops grown on lower grade land, and maximum value should be extracted through the exploitation of co-products and integrated biorefinery systems. Policy must continually emphasize the changes needed and tie incentives to improved greenhous gas reduction and environmental performance of biofuels.


Asunto(s)
Biocombustibles , Fuentes Generadoras de Energía , Inocuidad de los Alimentos , Biomasa , Conservación de los Recursos Naturales , Productos Agrícolas
7.
J Vasc Interv Radiol ; 21(8): 1262-70, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20656224

RESUMEN

PURPOSE: Paclitaxel is an antiproliferative agent in drug-eluting stents with largely unknown tissue interaction. Toxicity might result from overdosage and/or accumulation. Part 1 of this two-step study investigated how paclitaxel uptake depends on dose density, coronary drug transfer kinetics, and elution efficacy. MATERIALS AND METHODS: With cobalt chromium stents and Polyzene-F nanoscale coating, low, intermediate, and high paclitaxel dose densities (25 microg, 50 microg, and 150 microg per stent) were investigated in porcine right coronary arteries (RCAs). Coronary and myocardial tissue concentration measurements and determination of on-stent paclitaxel and plasma concentrations were performed at 2, 8, 24, and 72 hours. RESULTS: For all stents, uptake was similar at all time intervals (paclitaxel RCA concentration range, 1,610-33,300 ng). Low- and intermediate-dose stents showed similar RCA concentrations, but those for high-dose stents were three times greater. Residual on-stent paclitaxel concentration was not time-dependent, at 33.3% on low-, 30.6% on intermediate-, and 17.4% on high-dose stents. Paclitaxel was measurable in only the plasma immediately after stent placement, with a linear dose relationship and a timely regression: measurements in high-dose stents were 0.0454-0.656 ng/mL at 1 minute and 0.0329-0.0879 ng/mL at 5 minutes. Untreated control samples of the left coronary artery showed a linear dose-dependent concentration (12.6 ng/g, 21.2 ng/g, and 85.2 ng/g). CONCLUSIONS: Overall coronary paclitaxel uptake is fairly independent from the baseline overall dose density and, hence, depends on immediate binding mechanisms of the arterial wall. This is supported by the fact that, regardless of the applied dose density, the kinetics of paclitaxel uptake did not follow an exposure time pattern.


Asunto(s)
Angioplastia Coronaria con Balón/instrumentación , Fármacos Cardiovasculares/farmacocinética , Materiales Biocompatibles Revestidos , Vasos Coronarios/metabolismo , Stents Liberadores de Fármacos , Inflamación/metabolismo , Paclitaxel/farmacocinética , Angioplastia Coronaria con Balón/efectos adversos , Animales , Disponibilidad Biológica , Fármacos Cardiovasculares/administración & dosificación , Fármacos Cardiovasculares/sangre , Fármacos Cardiovasculares/toxicidad , Aleaciones de Cromo , Vasos Coronarios/efectos de los fármacos , Vasos Coronarios/patología , Relación Dosis-Respuesta a Droga , Femenino , Inflamación/inducido químicamente , Inflamación/patología , Modelos Animales , Miocardio/metabolismo , Paclitaxel/administración & dosificación , Paclitaxel/sangre , Paclitaxel/toxicidad , Polímeros , Diseño de Prótesis , Porcinos , Porcinos Enanos , Distribución Tisular
8.
Sci Total Environ ; 739: 139092, 2020 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-32521338

RESUMEN

The sustainability of grazing lands lies in the nexus of human consumption behavior, livestock productivity, and environmental footprint. Due to fast growing global food demands, many grazing lands have suffered from overgrazing, leading to soil degradation, air and water pollution, and biodiversity losses. Multidisciplinary efforts are required to understand how these lands can be better assessed and managed to attain predictable outcomes of optimal benefit to society. This paper synthesizes our understanding based on previous work done on modelling the influences of grazing of soil carbon (SC) and greenhouse gas emissions to identify current knowledge gaps and research priorities. We revisit three widely-used process-based models: DeNitrification DeComposition (DNDC), DayCent, and the Pasture Simulation model (PaSim) and two watershed models: The Soil & Water Assessment Tool (SWAT) and Variable Infiltration Capacity Model (VIC), which are widely used to simulate C, nutrient and water cycles. We review their structures and ability as process-based models in representing key feedbacks among grazing management, SOM decomposition and hydrological processes in grazing lands. Then we review some significant advances in the use of models combining biogeochemical and hydrological processes. Finally, we examine challenges of incorporating spatial heterogeneity and temporal variability into modelling C and nutrient cycling in grazing lands and discuss their weakness and strengths. We also highlight key research direction for improving the knowledge base and code structure in modelling C and nutrient cycling in grazing lands, which are essential to conserve grazing lands and maintain their ecosystem goods and services.

9.
Sci Total Environ ; 725: 138072, 2020 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-32298896

RESUMEN

Irrigated dryland agroecosystems could become more sustainable if crop and soil management enhanced soil organic carbon (SOC). We hypothesized that combining high inputs from cover crops with no-tillage will increase long-term SOC stocks. Caatinga shrublands had been cleared in 1972 for arable crops and palm plantations before implementing field experiments on Mango and Melon systems (established in 2009 and 2012, respectively). Each of the two experiments were managed with no-till (NT) or conventional till (CT), and three types of cover cropping, either a plant mixture of 75% (PM1) or 25% (PM2) legumes, or spontaneous vegetation (SV). The RothC model was used with a daily timestep to simulate the soil moisture dynamics and C turnover for this dry climate. Carbon inputs were between 2.62 and 5.82 Mg C ha-1 year-1 and increased the depleted SOC stocks by 0.08 to 0.56 Mg C ha-1 year-1. Scenarios of continuous biomass inputs of ca. 5 Mg C ha-1 year-1 for 60 years are likely to increase SOC stocks in the mango NT beyond the original Caatinga SOC by between 19.2 and 20.5 Mg C ha-1. Under CT similar inputs would increase SOC stocks only marginally above depletion (2.75 to 2.47 Mg C ha-1). Under melon, annual carbon inputs are slightly greater (up to 5.5 Mg C ha-1 year-1) and SOC stocks would increase on average by another 8% to 22.3 to 20.6 Mg C ha-1 under NT and by 8 Mg C ha-1 under CT. These long-term simulations show that combining NT with high quality cover crops (PM1, PM2) would exceed SOC stocks of the initial Caatinga within 20 and 25 years under irrigated melon and mango cultivation, respectively. These results present a solution to reverse prior loss of SOC by replacing CT dryland agriculture with irrigated NT plus high input cover crops agroecosystems.

10.
Rofo ; 192(11): 1025-1035, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32215900

RESUMEN

BACKGROUND: Postoperative lymphatic leakage (PLL) is usually managed by conservative and/or surgical treatments but these procedures can be challenging to perform and potentially clinically ineffective. Therefore, conventional lymphangiography (CL) has emerged as an important alternative. The aim of this review is to present the available outcome data on CL in the management of PLL. METHOD: A systematic literature search (PubMed) using the MeSH term "lymphangiography" was performed and the search was restricted to literature published between January 2007 and August 2019. Identification, screening, and assessment for eligibility and inclusion were conducted in accordance with PRISMA. RESULTS: From the initially obtained 1006 articles (identification), 28 articles with a total of 201 patients were finally included (inclusion). The methodological quality of all included articles corresponds to level 4 (Oxford Centre for Evidence-based Medicine - Levels of Evidence, March 2009). PLL occurs after oncological and non-oncological surgery in the form of chylothorax, chylous ascites, and cervical, thoracic, abdominal and peripheral lymph fistula and/or lymphocele. The technical success rate of CL is 75-100 %. Access for CL is transpedal (176 patients) or intranodal (25 patients). Lipiodol is used as the contrast material in all articles, with a maximum amount of 20 ml for transpedal CL and 30 ml for intranodal CL. The X-ray imaging modalities used for CL are fluoroscopy, radiography and/or CT. Two articles report CL-associated major complications and CL-associated morbidity and mortality. The PLL cure rate is 51-70 % for transpedal CL (time to PLL cure: 2-29 days) and 33-100 % for intranodal CL (time to PLL cure: 2-< 30 days). Bailout procedures in the case of clinically ineffective CL include a range of treatments. CONCLUSION: CL is feasible, safe, and effective in the management of PLL. Lipiodol as the contrast material is essential in CL because the highly viscous iodinated poppy-seed oil has not only diagnostic but therapeutic effects. Guidelines and randomized controlled trials are further steps towards defining the ultimate value of CL. KEY POINTS: · PLL is a difficult-to-treat and potentially life-threatening surgical complication.. · CL has emerged as an alternative to conservative/surgical treatment of PLL.. · CL is feasible, safe, and effective in the management of PLL. · Lipiodol-based CL can be regarded as a therapeutic procedure.. · Guidelines and randomized controlled trials are further important steps.. CITATION FORMAT: · Sommer CM, Pieper CC, Itkin M et al. Conventional Lymphangiography (CL) in the Management of Postoperative Lymphatic Leakage (PLL): A Systematic Review. Fortschr Röntgenstr 2020; 192: 1025 - 1035.


Asunto(s)
Enfermedades Linfáticas/diagnóstico por imagen , Enfermedades Linfáticas/terapia , Linfografía , Complicaciones Posoperatorias/diagnóstico por imagen , Complicaciones Posoperatorias/terapia , Quilotórax/diagnóstico por imagen , Quilotórax/terapia , Ascitis Quilosa/diagnóstico por imagen , Ascitis Quilosa/terapia , Aceite Etiodizado/administración & dosificación , Estudios de Factibilidad , Fístula/diagnóstico por imagen , Fístula/terapia , Fluoroscopía , Humanos , Linfocele/diagnóstico por imagen , Linfocele/terapia , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
11.
J Vasc Interv Radiol ; 20(12): 1608-16, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19944986

RESUMEN

PURPOSE: In part 1 of the present study, the authors demonstrated that coronary paclitaxel uptake from drug eluting stents (DESs) was not dependent on exposure time and dose. In this second part, the effect of the different paclitaxel dose densities on long-term biologic behavior was evaluated. MATERIALS AND METHODS: In 40 minipigs, (with 4- and 12-week follow-up), identical stents with the same three paclitaxel dose densities as in part 1 were implanted in the right coronary artery. Minipigs implanted with Polyzene-F nanocoated stents served as the control group. Quantitative angiography measuring average luminal diameter (from three in-stent reference points), minimal luminal diameter (from the point of maximum in-stent stenosis), average late loss, maximum late loss, and binary stenosis rate was performed, as was microscopy to determine neointimal thickening, injury score, and inflammation. RESULTS: All three DESs were associated with a high average late loss, binary stenosis rate, and neointimal thickening, without significant differences. Drug-free stents had significantly less late in-stent stenosis: there was an average late loss of 0.3 mm +/- 0.3 in drug-free stents versus 0.8 mm +/- 0.2 in intermediate-dose stents and 1.5 mm +/- 0.6 in high-dose stents (P = .04). DES-associated inflammation was high in all DESs and six times higher as in the drug-free stents (Kornowski scores of 0.2 +/- 0.1 in drug-free stents, 1.3 +/- 0.9 in low-dose stents, 1.7 +/- 0.8 in intermediate-dose stents, and 1.3 +/- 1.0 in high-dose stents; P = .04). It worsened with time in all DESs, as did late in-stent stenosis. CONCLUSIONS: The extensive and long-term retention of paclitaxel even in a low-dose formulation, at least according to the present labeling of DESs, might be associated with negative long-term results with regard to inflammation and late in-stent stenosis.


Asunto(s)
Angioplastia Coronaria con Balón/instrumentación , Fármacos Cardiovasculares/toxicidad , Materiales Biocompatibles Revestidos , Reestenosis Coronaria/inducido químicamente , Vasos Coronarios/efectos de los fármacos , Stents Liberadores de Fármacos , Inflamación/inducido químicamente , Paclitaxel/toxicidad , Angioplastia Coronaria con Balón/efectos adversos , Animales , Fármacos Cardiovasculares/administración & dosificación , Angiografía Coronaria , Reestenosis Coronaria/diagnóstico por imagen , Reestenosis Coronaria/patología , Vasos Coronarios/patología , Relación Dosis-Respuesta a Droga , Femenino , Inflamación/diagnóstico por imagen , Inflamación/patología , Modelos Animales , Paclitaxel/administración & dosificación , Diseño de Prótesis , Falla de Prótesis , Porcinos , Porcinos Enanos , Factores de Tiempo
12.
J Vasc Interv Radiol ; 20(12): 1597-607, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19944985

RESUMEN

PURPOSE: To determine the arterial distribution pattern of the embolic agent Embozene within the porcine kidney and compare it with those of other spherical embolic agents. MATERIALS AND METHODS: Embozene, Embosphere, Bead Block, and Contour SE in size classes of 100-300 microm, 500-700 microm, and 700-900 microm and Embozene and Embosphere in the size class of 40-120 microm were used for total arterial occlusion in minipig kidneys. Organs were evaluated microscopically regarding vascular distribution of the different embolic agents and particle sizes. RESULTS: The following variations of arterial distribution were identified. In the 40-120-microm size class, Embosphere particles penetrated significantly deeper compared with Embozene (P = .04). In the 100-300-microm size class, Bead Block showed a significantly deeper distribution as microscopy identified particles in arteries much smaller than their nominal size. In the 500-700-microm size class, Embosphere and Contour SE showed a deeper distribution. The most uniform arterial distribution was observed in the 700-900 microm size class,. However, few Embosphere and Contour SE particles were found in arcuate arteries, also indicating a distal distribution. CONCLUSIONS: Throughout the four most-used size classes, from very small (40-120 microm) to large (700-900 microm), the distribution characteristics of the four tested materials vary substantially. Particularly, small Embosphere particles and small Bead Block particles showed a more distal distribution, as did medium-sized Embosphere and Contour SE particles. In the largest investigated size class, the distribution was more uniform. In general, the Embozene particles are very uniform in size, and they seem to reach vessels closely corresponding to their nominal size.


Asunto(s)
Embolización Terapéutica/métodos , Riñón/irrigación sanguínea , Polímeros/administración & dosificación , Arteria Renal , Resinas Acrílicas/administración & dosificación , Animales , Gelatina/administración & dosificación , Hidrogel de Polietilenoglicol-Dimetacrilato/administración & dosificación , Inyecciones Intraarteriales , Modelos Animales , Compuestos Organofosforados/administración & dosificación , Tamaño de la Partícula , Alcohol Polivinílico/administración & dosificación , Radiografía , Arteria Renal/anatomía & histología , Arteria Renal/diagnóstico por imagen , Porcinos , Porcinos Enanos
13.
J Vasc Interv Radiol ; 20(7): 927-35, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19497761

RESUMEN

PURPOSE: To compare outcomes with a thermoplastic polyurethane (TPU)-covered self-expanding nitinol stent-graft (TPU graft) with those of a bare self-expanding nitinol stent in a porcine model. MATERIALS AND METHODS: Fourteen TPU grafts and 14 commercially available bare nitinol stents were implanted, one each, in the iliac arteries of 14 minipigs. Follow-up was performed at 1 week (six animals), 4 weeks (four animals), and 12 weeks (four animals). The primary study endpoint was in-stent stenosis assessed with quantitative angiography and microscopy. Secondary endpoints were injury, inflammation, and endothelialization. RESULTS: After 1 week, the maximum percentage luminal loss was significantly greater in TPU grafts (average, 16.2%; range, 0.0%-35.8%) than in bare nitinol stents (8.2%; 0.0%-17.3%) (P = .04). Three of the four TPU grafts were occluded after 4 weeks, and all four TPU grafts were occluded after 12 weeks. Binary stenosis was seen in three of four bare nitinol stents after both 4 and 12 weeks. At 4-week follow-up, the average percentage luminal loss was significantly greater in TPU grafts (85.2%; 40.8%-100%) than in bare nitinol stents (49.5%; 37.9%-62.4%) (P = .003). The difference in neointimal height and percentage average stenosis between TPU grafts (1,028.7 microm and 68.4%) and bare nitinol stents (1,033.6 microm [918.0-1,118.40 microm] and 68.1% [60.44%-71.99%]) was not statistically significant. After 12 weeks, the average percentage luminal loss was 100% in TPU grafts due to occlusion of all stent-grafts and 24.9% (8.0%-63.9%) in bare nitinol stents (P = .011). CONCLUSIONS: TPU grafts failed to provide improved patency compared with the bare nitinol stents because of excessive neointimal growth and subsequent occlusion. In addition, the bare nitinol stents showed considerable in-stent stenosis at angiography and microscopy.


Asunto(s)
Prótesis Vascular/efectos adversos , Modelos Animales de Enfermedad , Oclusión de Injerto Vascular/etiología , Arteria Ilíaca/cirugía , Poliuretanos/efectos adversos , Stents/efectos adversos , Aleaciones/efectos adversos , Aleaciones/química , Animales , Materiales Biocompatibles Revestidos/química , Diseño de Equipo , Análisis de Falla de Equipo , Oclusión de Injerto Vascular/diagnóstico , Calor , Humanos , Arteria Ilíaca/diagnóstico por imagen , Arteria Ilíaca/patología , Plásticos/efectos adversos , Plásticos/química , Poliuretanos/química , Porosidad , Radiografía , Porcinos
14.
J Vasc Interv Radiol ; 20(7): 936-45, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19555888

RESUMEN

PURPOSE: To evaluate the immunohistochemical inflammatory reaction after porcine renal embolization with the new spherical embolic agent Embozene and to compare it with other spherical embolic agents. MATERIALS AND METHODS: After superselective porcine renal embolization (40 pigs) with different sizes of embolic agents (Embozene, Embosphere, Bead Block, Contour SE), tissue arrays were obtained (size ranges, 40-120 microm, 100-300 microm, 500-700 microm, 700-900 microm). After immunostaining for CD subtyping (CD45 and CD68) and cytokines (C-reactive protein [CRP] and interleukin-1 beta), a semiquantitative immunoreactivity score was calculated for each marker: intensity of staining was scored between 0 (negative) and 3 (intensive) and extent of staining between 0 and 4 (>80%), indicating the percentage of positive staining. The intensity score (0-3) was multiplied by the extent of staining score (0-4), resulting in a semiquantitative immunoreactivity score (0-12). RESULTS: Analysis of cellular expression profiles (ie, CD45, CD68) revealed a significantly higher inflammatory score 4 weeks after embolization with Embosphere 100-300 microm particles than after embolization with Embozene, Bead Block, and Contour SE. After 12 weeks, the Embosphere 100-300 microm score decreased. Analysis of CRP expression showed similar results, with a significantly higher score 4 weeks after embolization with Embosphere 100-300 microm. In the size class used most frequently for uterine artery emboliation (500-700 microm), all scores were low (<2.5) and there was no significant difference among particle types. CONCLUSIONS: Pronounced immunomarker expression was seen 4 weeks after embolization with small Embosphere particles. However, in general, modern spherical embolic agents cause a fairly low level of inflammatory reaction. In the present experimental setting, which is highly sensitive for specific tissue-to-agent reactivity, Embozene presented with low inflammatory results.


Asunto(s)
Resinas Acrílicas/efectos adversos , Modelos Animales de Enfermedad , Gelatina/efectos adversos , Hemostáticos/efectos adversos , Nefritis/inducido químicamente , Nefritis/patología , Embolización de la Arteria Uterina/efectos adversos , Animales , Humanos , Riñón/efectos de los fármacos , Riñón/patología , Porcinos , Porcinos Enanos
15.
Sci Total Environ ; 634: 1108-1118, 2018 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-29660867

RESUMEN

To optimise trade-offs provided by future changes in grassland use intensity, spatially and temporally explicit estimates of respective grassland productivities are required at the systems level. Here, we benchmark the potential national availability of grassland biomass, identify optimal strategies for its management, and investigate the relative importance of intensification over reversion (prioritising productivity versus environmental ecosystem services). Process-conservative meta-models for different grasslands were used to calculate the baseline dry matter yields (DMY; 1961-1990) at 1km2 resolution for the whole UK. The effects of climate change, rising atmospheric [CO2] and technological progress on baseline DMYs were used to estimate future grassland productivities (up to 2050) for low and medium CO2 emission scenarios of UKCP09. UK benchmark productivities of 12.5, 8.7 and 2.8t/ha on temporary, permanent and rough-grazing grassland, respectively, accounted for productivity gains by 2010. By 2050, productivities under medium emission scenario are predicted to increase to 15.5 and 9.8t/ha on temporary and permanent grassland, respectively, but not on rough grassland. Based on surveyed grassland distributions for Great Britain in 2010 the annual availability of grassland biomass is likely to rise from 64 to 72milliontonnes by 2050. Assuming optimal N application could close existing productivity gaps of ca. 40% a range of management options could deliver additional 21∗106tonnes of biomass available for bioenergy. Scenarios of changes in grassland use intensity demonstrated considerable scope for maintaining or further increasing grassland production and sparing some grassland for the provision of environmental ecosystem services.

16.
Rofo ; 190(3): 250-258, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-28934806

RESUMEN

PURPOSE: To compare radiation exposure of a state-of-the-art and a conventional angiography unit in patients undergoing uterine fibroid embolization (UFE). MATERIALS AND METHODS: Between January 2009 and December 2016, 286 patients underwent UFE in our Interdisciplinary Fibroid Center. The inclusion criteria for this retrospective analysis were first-time transarterial embolization for symptomatic fibroids, bilateral embolization, procedures applying a state-of-the-art (Group 1) or a conventional angiography unit (Group 2), and bilateral technical success with an adequate embolization endpoint after the injection of microspheres. Study endpoints included radiation exposure, major complications, morphological success (MRI), and clinical success (questionnaire on quality-of-life). Propensity score matching controlled for confounders. RESULTS: The inclusion criteria were met by 58 (Group 1) and 177 (Group 2) patients. After propensity score matching, there was no significant difference between Group 1 (n = 46) and Group 2 (n = 92) regarding age, body-mass index, volume of the dominant fibroid and the uterus, fluoroscopy time, and amount of embolic agent (p ≥ 0.10 each). The dose-area product was significantly lower in Group 1 than in Group 2 (1159.0 cGycm2 vs. 3123.5 cGycm2; p < 0.001), while major complication rates (both groups 0 %) and dominant fibroid devascularization (both groups 100 %) were equal (p > 0.99). There were no significant differences between both groups regarding shrinkage of the dominant fibroid and the uterus and no relevant differences regarding patient-reported quality-of-life. CONCLUSION: A state-of-the-art angiography unit has the potential to reduce radiation exposure in patients undergoing UFE without increasing the risk of major complications and with comparably high morphological and clinical success. KEY POINTS: · A state-of-the-art angiography unit potentially reduces radiation exposure in patients undergoing UFE.. · Reduced radiation exposure does not seem to negatively influence the rate of major complications.. · Reduced exposure does not seem to negatively affect morphological and clinical success.. CITATION FORMAT: · Sommer C, Voigt W, Oliger MK et al. Radiation Exposure During Uterine Fibroid Embolization (UFE): A Confounder-Controlled Comparison Between a State-of-the-Art Angiography Unit and a Conventional Angiography unit. Fortschr Röntgenstr 2018; 190: 250 - 258.


Asunto(s)
Angiografía/instrumentación , Diseño de Equipo , Seguridad de Equipos , Leiomioma/terapia , Exposición a la Radiación , Embolización de la Arteria Uterina/instrumentación , Neoplasias Uterinas/terapia , Adulto , Anestesia Epidural , Angiografía de Substracción Digital , Seguridad de Equipos/instrumentación , Femenino , Humanos , Plexo Hipogástrico , Leiomioma/irrigación sanguínea , Leiomioma/diagnóstico por imagen , Persona de Mediana Edad , Bloqueo Nervioso , Calidad de Vida , Estudios Retrospectivos , Encuestas y Cuestionarios , Resultado del Tratamiento , Neoplasias Uterinas/irrigación sanguínea , Neoplasias Uterinas/diagnóstico por imagen
17.
Invest Radiol ; 42(5): 303-11, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17414526

RESUMEN

OBJECTIVES: Previous experimental studies have demonstrated that poly[bis(trifluoroethoxy)phosphazene] (PTFEP) nanocoated stents have antithrombotic characteristics, reduce in-stent stenosis, prevent wall inflammation, and do not hamper endothelialization. This study was designed to validate these findings in a porcine coronary artery model. MATERIALS AND METHODS: PTFEP-coated (n = 15) and bare stents (n= 13) were implanted in coronary arteries of 18 mini-pigs (4- and 12-week follow-up). Primary study endpoints were thrombogenicity and in-stent stenosis, secondary study endpoints were inflammatory response and re-endothelialization evaluated by quantitative angiography and light microscopy. RESULTS: No thrombus deposition occurred on any stent. At 4 weeks follow-up, the bare stents (n = 4) had a significantly smaller neointimal area (1.93 vs. 3.20 mm(2), P = 0.009). At 12 weeks, PTFEP-coated stents (n = 11) had significantly superior results in almost all parameters: neointimal area (2.25 vs. 2.65 mm(2), P = 0.034), neointimal height (204.46 vs. 299.41 microm, P = 0.048), percentage stenosis (38.25 vs. 50.42%, P = 0.019), and inflammation score (0.12 vs. 0.30, P = 0.029). Complete re-endothelialization was seen in both stent types at both intervals. CONCLUSION: At long-term follow-up, the superior results of PTFEP-coated stents were characterized by a noteworthy reduction of neointimal growth and inflammatory response.


Asunto(s)
Materiales Biocompatibles Revestidos , Vasos Coronarios , Compuestos Organofosforados , Polímeros , Stents , Trombosis/prevención & control , Animales , Angiografía Coronaria , Vasos Coronarios/patología , Modelos Animales , Diseño de Prótesis , Acero Inoxidable , Porcinos , Porcinos Enanos , Túnica Íntima/patología , Grado de Desobstrucción Vascular
19.
Resuscitation ; 73(3): 362-73, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17287064

RESUMEN

INTRODUCTION: Successful management of emergency patients with multiple trauma in the hospital resuscitation room depends on the immediate diagnosis and rapid treatment of the most life-threatening injuries. In order to reduce the time spent in the resuscitation room, an in-hospital algorithm was developed in an interdisciplinary team approach with respect to local structures. The aim of the study was to analyse whether this algorithm affects the interval between hospital admission and the completion of diagnostic procedures and the start of life-saving interventions. Moreover, in-hospital mortality was investigated before and after the algorithm was introduced. MATERIAL AND METHODS: In this prospective study, all consecutive trauma patients in the resuscitation room were investigated before (group I, 01/04-10/04) and after (group II, 01/05-11/05) introduction of the algorithm. The times between hospital admission and the end of the diagnostic procedures (ultrasound [sono], chest X-ray [CF], and cranial computed tomography [CCT]), and between hospital admission and the start of life-saving interventions were registered and in-hospital mortality analysed. RESULTS: In the study period, 170 patients in group I and 199 patients in group II were investigated. Injury severity score (ISS) were comparable between the two groups. The intervals between admission and completion of diagnostic procedures were significantly lower after the algorithm was introduced (mean+/-S.D.): sono (11 +/- 10 min versus 7 +/- 6 min, p < 0.05), CF (21 +/- 12 min versus 12 +/- 9 min, p < 0.01), and CCT (55 +/- 27 min versus 32 +/- 14 min, p < 0.01). Moreover, the interval to the start of life-saving interventions was significantly shorter (126 +/- 90 min versus 51 +/- 20 min, p < 0.01). After introducing the algorithm, in-hospital mortality was reduced significantly from 33.3% to 16.7% (p < 0.05) in the most severely injured patients (ISS>or=25). CONCLUSION: The introduction of an algorithm for early management of emergency patients significantly reduced the time spent in the resuscitation room. The periods to completion of sono, CF, and CCT, respectively, and the start of life-saving interventions were significantly shorter after introduction of the algorithm. Moreover, introduction of the algorithm reduced mortality in the most severely injured patients. Although further investigations are needed to evaluate the effects of the Heidelberg treatment algorithm in terms of outcome and mortality, the time reduction in the resuscitation room seems to be beneficial.


Asunto(s)
Traumatismo Múltiple/diagnóstico , Resucitación/normas , Centros Traumatológicos/normas , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Algoritmos , Niño , Preescolar , Femenino , Alemania , Humanos , Masculino , Persona de Mediana Edad , Traumatismo Múltiple/mortalidad , Traumatismo Múltiple/cirugía , Estudios Prospectivos , Factores de Tiempo
20.
Glob Change Biol Bioenergy ; 9(3): 489-507, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28331551

RESUMEN

Planting the perennial biomass crop Miscanthus in the UK could offset 2-13 Mt oil eq. yr-1, contributing up to 10% of current energy use. Policymakers need assurance that upscaling Miscanthus production can be performed sustainably without negatively impacting essential food production or the wider environment. This study reviews a large body of Miscanthus relevant literature into concise summary statements. Perennial Miscanthus has energy output/input ratios 10 times higher (47.3 ± 2.2) than annual crops used for energy (4.7 ± 0.2 to 5.5 ± 0.2), and the total carbon cost of energy production (1.12 g CO2-C eq. MJ-1) is 20-30 times lower than fossil fuels. Planting on former arable land generally increases soil organic carbon (SOC) with Miscanthus sequestering 0.7-2.2 Mg C4-C ha-1 yr-1. Cultivation on grassland can cause a disturbance loss of SOC which is likely to be recovered during the lifetime of the crop and is potentially mitigated by fossil fuel offset. N2O emissions can be five times lower under unfertilized Miscanthus than annual crops and up to 100 times lower than intensive pasture. Nitrogen fertilizer is generally unnecessary except in low fertility soils. Herbicide is essential during the establishment years after which natural weed suppression by shading is sufficient. Pesticides are unnecessary. Water-use efficiency is high (e.g. 5.5-9.2 g aerial DM (kg H2O)-1, but high biomass productivity means increased water demand compared to cereal crops. The perennial nature and belowground biomass improves soil structure, increases water-holding capacity (up by 100-150 mm), and reduces run-off and erosion. Overwinter ripening increases landscape structural resources for wildlife. Reduced management intensity promotes earthworm diversity and abundance although poor litter palatability may reduce individual biomass. Chemical leaching into field boundaries is lower than comparable agriculture, improving soil and water habitat quality.

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