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1.
Circ Econ Sustain ; 3(1): 475-510, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35855295

RESUMO

Current rising concerns about environmental and climate impacts in production, consumption and end-of-life of plastics have led to efforts to switch from linear to circular economy of plastics in Europe. Greenhouse gas emissions are likely to decrease with a transition to a circular system; however, a systematic and integrated perspective on plastics and the carbon cycle is currently missing in the debate on plastics. In this study, a model to estimate greenhouse gas emissions of the current mostly linear plastics value chain of the EU in 2018 and a future scenario, 2025 model, were created. By 2025 if current policy targets are reached, the plastic packaging recycling rate should be 50%, PET-based drinking bottles should include 25% recycled content, 77% collection target for plastic bottles, 10 Mt recyclates should enter the markets, uptake of bio-based plastics is estimated by European bioplastics to increase from current 1 to 1.32% and landfilling will continue to decrease according to the current trend at 3.85%. Total greenhouse gas emissions caused by the current plastics value chain are estimated at 208 million tonnes of CO2-eq. The 2025 model estimates that total plastics value chain emissions will be 182 Mt of CO2-eq. Reduction potential is approximately 26 Mt of CO2-eq or 13%.

2.
Scand Cardiovasc J ; 51(3): 143-152, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28335644

RESUMO

OBJECTIVES: The objective of this pilot study was to describe the impact of paced heart rate on left ventricular (LV) mechanical dyssynchrony in synchronous compared to dyssynchronous pacing modes in patients with heart failure. METHODS: Echocardiography was performed in 14 cardiac resynchronization therapy (CRT) patients at paced heart rates of 70 and 90 bpm in synchronous- (CRT), and dyssynchronous (atrial pacing + wide QRS activation) pacing modes. LV dyssynchrony was quantified using the 12-segment standard deviation model (Ts-SD) derived from Tissue Doppler Imaging. In addition, cardiac cycle intervals were assessed using cardiac state diagrams and stroke volume (SV) and filling pressure were estimated. RESULTS: Ts-SD decreased significantly with CRT at 90 bpm (25 ± 12 ms) compared to 70 bpm (35 ± 15 ms, p = .01), but remained unchanged with atrial pacing at different paced heart rates (p = .96). The paced heart rate dependent reduction in Ts-SD was consistent when Ts-SD was indexed to average Ts and systolic time interval. Cardiac state diagram derived analysis of cardiac cycle intervals demonstrated a significant reduction of the pre-ejection interval and an increase in diastole with CRT compared to atrial pacing. SV was maintained at the higher paced heart rate with CRT pacing but decreased with atrial pacing. DISCUSSION: Due to the small sample size in this pilot study general and firm conclusions are difficult to render. However, the data suggest that pacing at higher heart rates acutely reduces remaining LV dyssynchrony during CRT, but not during atrial pacing with dyssynchronous ventricular activation. These results need confirmation in a larger patient cohort.


Assuntos
Terapia de Ressincronização Cardíaca/métodos , Insuficiência Cardíaca/terapia , Frequência Cardíaca , Disfunção Ventricular Esquerda/terapia , Função Ventricular Esquerda , Idoso , Terapia de Ressincronização Cardíaca/efeitos adversos , Ecocardiografia Doppler em Cores , Ecocardiografia Doppler de Pulso , Feminino , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Volume Sistólico , Fatores de Tempo , Resultado do Tratamento , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/fisiopatologia , Pressão Ventricular
3.
Pacing Clin Electrophysiol ; 40(5): 504-513, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28206674

RESUMO

BACKGROUND: Spinal cord stimulation (SCS) reduces sympathetic activity in animal models of heart failure with reduced ejection fraction (HF) but limited data exist of SCS in patients with HF. The aim of the present study was to test the primary hypothesis that SCS reduces cardiac sympathetic nerve activity in HF patients. Secondary hypotheses were that SCS improves left ventricular function and dimension, exercise capacity, and clinical variables relevant to HF. METHODS: HF patients with a SCS device previously participating in the DEFEAT-HF trial were included in this crossover study with 6-week intervention periods (SCS-ON and SCS-OFF). SCS (50 Hz, 210-µs pulse duration, aiming at T2-T4 segments) was delivered for 12 hours daily. Indices of myocardial sympathetic neuronal function (heart-to-mediastinum ratio, HMR) and activity (washout rate, WR) were assessed using 123 I-metaiodobenzylguanidine (MIBG) scintigraphy. Echocardiography, exercise testing, and clinical data collection were also performed. RESULTS: We included 13 patients (65.3 ± 8.0 years, nine males) and MIBG scintigraphy data were available in 10. HMR was not different comparing SCS-ON (1.37 ± 0.16) and SCS-OFF (1.41 ± 0.21, P = 0.46). WR was also unchanged comparing SCS-ON (41.5 ± 5.3) and SCS-OFF (39.1 ± 5.8, P = 0.30). Similarly, average New York Heart Association class (2.4 ± 0.5 vs 2.3 ± 0.6, P = 0.34), quality of life score (24 ± 16 vs 24 ± 16, P = 0.94), and left ventricular dimension and function as well as exercise capacity were all unchanged comparing SCS-ON and SCS-OFF. CONCLUSION: In patients with HF, SCS (12 hours daily, targeting the T2-T4 segments of the spinal cord) does not appear to influence cardiac sympathetic neuronal activity or function as assessed by MIBG scintigraphy.


Assuntos
Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Coração/inervação , Coração/fisiopatologia , Estimulação da Medula Espinal/métodos , Medula Espinal/fisiopatologia , Sistema Nervoso Simpático/fisiopatologia , Idoso , Feminino , Coração/diagnóstico por imagem , Humanos , Masculino , Medula Espinal/diagnóstico por imagem , Resultado do Tratamento
5.
Scand Cardiovasc J ; 50(5-6): 282-292, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27577107

RESUMO

Heart failure (HF) is considered as an epidemic and affects 2% of the population in the Western world. About 15-30% of patients with HF and reduced ejection fraction (HFrEF) also have prolonged QRS duration on the surface ECG, most commonly as a result of left-bundle branch block (LBBB). Increased QRS duration is a marker of a dyssynchronous activation, and subsequent contraction, pattern in the left ventricle (LV). When dyssynchrony is superimposed on the failing heart it further reduced systolic function and ultimately worsens outcome. During the past 15 years several randomized controlled clinical trials have documented that resynchronization of the dyssynchronous failing heart with a biventricular pacemaker - cardiac resynchronization therapy (CRT) - which can restore a more synchronous activation and contraction pattern. This translates in halted or reversed disease progression and improved clinical outcome, including reduced mortality. In this review, we will discuss several aspects of CRT including mechanisms of dyssynchrony and resynchronization in the failing heart, evidence of CRT efficacy derived from clinical trials and current challenges in CRT including patient selection and optimization of therapy delivery. Last, we will discuss future perspectives including the role of CRT to prevent adverse events in patients with an indication for antibradycardia pacing, the role of leadless pacing in the CRT setting as well as a new clinical arena where dyssynchrony and resynchronization may be important.


Assuntos
Dispositivos de Terapia de Ressincronização Cardíaca/tendências , Terapia de Ressincronização Cardíaca/tendências , Sistema de Condução Cardíaco/fisiopatologia , Insuficiência Cardíaca/terapia , Potenciais de Ação , Animais , Terapia de Ressincronização Cardíaca/efeitos adversos , Terapia de Ressincronização Cardíaca/mortalidade , Difusão de Inovações , Desenho de Equipamento , Previsões , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/fisiopatologia , Frequência Cardíaca , Humanos , Recuperação de Função Fisiológica , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
6.
Europace ; 17(3): 439-46, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25355780

RESUMO

AIMS: To test the hypothesis that acute increased biventricularly (BiV) paced heart rate (pHR) results in decreased muscle sympathetic nerve activity (MSNA), and that dyssynchronous pacing (AAI) attenuates this effect, in heart failure patients receiving cardiac resynchronization therapy (CRT). METHODS AND RESULTS: Fourteen CRT patients (NYHA II-III, 12 males, mean EF 28 ± 14%) were recruited. Three different pHRs (50-90 b.p.m.) were randomly programmed in BiV- and AAI-pacing modes. Muscle sympathetic nerve activity (total sympathetic nerve activity/min (units) and number of bursts/100 RR) were recorded from the peroneal nerve using a microelectrode. In addition, cardiac output (CO) and mean blood pressure (mBP) were measured. With BiV pacing, the total MSNA/min was lower at 70 b.p.m. (-7 ± 21%, P = 0.18) and 90 b.p.m. (-29 ± 18%, P = 0.01) compared with at 50 b.p.m. (280 ± 180 U). Similarly, bursts/100RR decreased with increased BiV pHR. Cardiac output (3.7 L/min at 50 b.p.m., +12 ± 12% at 70 b.p.m., and +18 ± 19% at 90 b.p.m.) and mBP (78 ± 11 mmHg at 50 b.p.m., +6 ± 6% at 70 b.p.m. and +11 ± 8% at 90 b.p.m.) increased significantly at elevated pHRs in BiV-pacing mode. The effect on MSNA, CO, and mBP was less pronounced in AAImode but we found no significant differences between the pacing modes. CONCLUSION: Increased pHR acutely reduces MSNA and improves haemodynamics in HF patients treated with CRT with no evident differences between BiV- and AAI-pacing modes. Further studies are warranted to guide the programming of basic pHR in CRT patients.


Assuntos
Terapia de Ressincronização Cardíaca/métodos , Insuficiência Cardíaca/terapia , Frequência Cardíaca , Músculo Esquelético/inervação , Nervo Fibular/fisiopatologia , Sistema Nervoso Simpático/fisiopatologia , Idoso , Feminino , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade
7.
J Hazard Mater ; 179(1-3): 573-80, 2010 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-20363074

RESUMO

Quantifying the spatial variability of factors affecting natural attenuation of hydrocarbons in the unsaturated zone is important to (i) performing a reliable risk assessment and (ii) evaluating the possibility for bioremediation of petroleum-polluted sites. Most studies to date have focused on the shallow unsaturated zone. Based on a data set comprising analysis of about 100 soil samples taken in a 16 m-deep unsaturated zone polluted with volatile petroleum compounds, we statistically and geostatistically analysed values of essential soil properties. The subsurface of the site was highly layered, resulting in an accumulation of pollution within coarse sandy lenses. Air-filled porosity, readily available phosphorous, and the first-order rate constant (k(1)) of benzene obtained from slurry biodegradation experiments were found to depend on geologic sample characterization (P<0.05), while inorganic nitrogen was homogenously distributed across the soil stratigraphy. Semivariogram analysis showed a spatial continuity of 4-8.6 m in the vertical direction, while it was 2-5 times greater in the horizontal direction. Values of k(1) displayed strong spatial autocorrelation. Even so, the soil potential for biodegradation was highly variable, which from autoregressive state-space modeling was partly explained by changes in soil air-filled porosity and gravimetric water content. The results suggest considering biological heterogeneity when evaluating the fate of contaminants in the subsurface.


Assuntos
Biodegradação Ambiental , Hidrocarbonetos/análise , Petróleo/análise , Poluentes do Solo/análise , Solo/análise , Algoritmos , Sedimentos Geológicos/análise , Modelos Estatísticos , Nitrogênio/análise , Fósforo/análise , Porosidade , Microbiologia do Solo
8.
Vadose Zone J ; 9(1): 137-147, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21617737

RESUMO

Naturally occurring biodegradation of petroleum hydrocarbons in the vadose zone depends on the physical soil environment influencing field-scale gas exchange and pore-scale microbial metabolism. In this study, we evaluated the effect of soil physical heterogeneity on biodegradation of petroleum vapors in a 16-m-deep, layered vadose zone. Soil slurry experiments (soil/water ratio 10:30 w/w, 25°C) on benzene biodegradation under aerobic and well-mixed conditions indicated that the biodegradation potential in different textured soil samples was related to soil type rather than depth, in the order: sandy loam > fine sand > limestone. Similarly, O(2) consumption rates during in situ respiration tests performed at the site were higher in the sandy loam than in the fine sand, although the difference was less significant than in the slurries. Laboratory and field data generally agreed well and suggested a significant potential for aerobic biodegradation, even with nutrient-poor and deep subsurface conditions. In slurries of the sandy loam, the biodegradation potential declined with increasing in situ water saturation (i.e., decreasing air-filled porosity in the field). This showed a relation between antecedent undisturbed field conditions and the slurry biodegradation potential, and suggested airfilled porosity to be a key factor for the intrinsic biodegradation potential in the field.

9.
J Am Vet Med Assoc ; 223(4): 495-500, 2003 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-12930089

RESUMO

OBJECTIVE: To determine prevalence of resistance to all anthelmintics that are commonly used to treat gastrointestinal nematodes (GINs) in goats. DESIGN: Prospective study. ANIMALS: 777 goats. PROCEDURE: On each farm, goats were assigned to 1 of 5 treatment groups: untreated controls, albendazole (20 mg/kg [9.0 mg/lb], p.o., once), ivermectin (0.4 mg/kg [0.18 mg/lb], p.o., once), levamisole (12 mg/kg [5.4 mg/lb], p.o., once), or moxidectin (0.4 mg/kg, p.o., once), except on 3 farms where albendazole was omitted. Fecal samples were collected 2 weeks after treatment for determination of fecal egg counts (FECs), and percentage reductions were calculated by comparing data from anthelmintic-treated and control groups. Nematode populations were categorized as susceptible, suspected resistant, or resistant by use of guidelines published by the World Association for the Advancement of Veterinary Parasitology. RESULTS: Resistance to albendazole was found on 14 of 15 farms, and resistance to ivermectin, levamisole, and moxidectin was found on 17, 6, and 1 of 18 farms, respectively. Suspected resistance to levamisole and moxidectin was found on 4 and 3 farms, respectively. Resistance to multiple anthelmintics (albendazole and ivermectin) was found on 14 of 15 farms and to albendazole, ivermectin, and levamisole on 5 of 15 farms. Mean overall FEC reduction percentages for albendazole, ivermectin, levamisole, and moxidectin were 67, 54, 94, and 99%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Anthelmintic resistance in GINs of goats is highly prevalent in the southern United States. The high prevalence of resistance to multiple anthelmintics emphasizes the need for reexamination of nematode control practices.


Assuntos
Anti-Helmínticos/farmacologia , Doenças das Cabras/tratamento farmacológico , Enteropatias Parasitárias/veterinária , Nematoides/efeitos dos fármacos , Infecções por Nematoides/veterinária , Albendazol/farmacologia , Albendazol/uso terapêutico , Animais , Anti-Helmínticos/uso terapêutico , Resistência a Medicamentos , Fezes/parasitologia , Feminino , Georgia/epidemiologia , Doenças das Cabras/epidemiologia , Doenças das Cabras/parasitologia , Cabras , Enteropatias Parasitárias/tratamento farmacológico , Enteropatias Parasitárias/epidemiologia , Ivermectina/farmacologia , Ivermectina/uso terapêutico , Levamisol/farmacologia , Levamisol/uso terapêutico , Masculino , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/epidemiologia , Contagem de Ovos de Parasitas/veterinária , Testes de Sensibilidade Parasitária/veterinária , Prevalência , Estudos Prospectivos , Distribuição Aleatória , South Carolina/epidemiologia
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