As the green hydrogen industry develops, hybrid renewable power supply configurations emerge as a solution to increasing electrolyzer load factor. In particular, solar photovoltaics (PV) paired with ...Battery Energy Storage Systems (BESS) will provide a suitable option for continuous power supply as their investment costs continue to decline during the next decade. An opportunity arises to use the plant’s energy resources to provide grid services without hindering hydrogen production. Motivated by this, this paper presents a chance-constrained stochastic model for the optimal operation scheduling of a PV-BESS-Electrolyzer system participating in energy and ancillary services markets. Scenarios are used to account for uncertainty in solar power availability and energy content of the frequency regulation signal, and a degradation model is included to properly consider the effect of repeated battery cycling. Computational experiments using PJM market data and a realistic time frame show the benefits of the proposed model, achieving 10.2% more profits than the deterministic benchmark problem, while maintaining low failure rates in the provision of the regulation service and a similar hydrogen production compared to an off-grid standalone operation.
•Scenarios are used to capture regulation signal energy content uncertainty.•Using batteries just for hydrogen production is not cost effective.•Frequency regulation is a significant source of income.•Hydrogen production is minimally affected by providing regulation services.•Battery degradation greatly diminishes in a grid connected plant.
Second-to-second renewable power fluctuations can severely hinder the frequency regulation performance of modern isolated microgrids, as these typically have a low inertia and significant renewable ...energy integration. In this context, the present paper studies the coordinated control of Thermostatically Controlled Loads (TCLs) for managing short-term power imbalances, and their integration in microgrid operations through the use of aggregate TCL models. In particular, two computationally efficient and accurate aggregate TCL models are developed: a virtual battery model representing the aggregate flexibility of TCLs considering solar irradiance heat gains and wall/floor heat transfers, and a frequency transient model representing the aggregate dynamics of a TCL collection considering communication delays and the presence of model uncertainty and time-variability. The proposed aggregate TCL models are then used to design a practical Energy Management System (EMS) integrating TCL flexibility, and study the impact of TCL integration on microgrid operation and frequency control. Computational experiments using detailed frequency transient and thermal dynamic models are presented, demonstrating the accuracy of the proposed aggregate TCL models, as well as the economic and reliability benefits resulting from using these aggregate models to integrate TCLs in microgrid operations.
The intracellular ROCK signaling pathway is an important modulator of blood pressure and of cardiovascular and renal remodeling when Rho-kinase activity is increased. Besides, in preclinical models ...of diabetes, ROCK activation has also a role in abnormal glucose metabolism as well as in subsequent vascular and myocardial dysfunction. In humans, there are a few data assessing ROCK activation in patients with type 2 diabetes mellitus (T2D) and no studies assessing upstream/downstream components of the ROCK pathway. We assessed here levels of ROCK activation and some of the RhoA/ROCK cascade molecules in peripheral blood mononuclear cells (PBMCs) in T2D patients under current treatment.
Cross-sectional observational study comparing 28 T2D patients under current antidiabetic treatment with 31 consecutive healthy subjects, matched by age and gender. Circulating levels of malondialdehyde, angiotensin II and inflammatory cytokines IL-6 and IL-8 were determined in all subjects. ROCK activation in PMBCs, upstream and downstream cascade proteins, and levels of the proinflammatory molecules VCAM, ICAM-1 and IL-8 were determined in their PMBCs by Western blot.
Compared to healthy controls, ROCK activation in T2D patients measured by 2 direct ROCK targets in PBMCs was increased by 420 and 570% (p < 0001) and it correlated significantly with serum glucose levels. p38 MAPK phosphorylation (downstream from ROCK) and JAK-2 (upstream from ROCK) were significantly higher in the T2D patients by 580% and 220%, respectively. In T2D patients, significantly increased PBMC levels of the proinflammatory molecules VCAM-1, ICAM-1 and IL-8 were observed compared to control subjects (by 180%, 360% and 260%, respectively). Circulating levels of Ang II and MDA were significantly higher in T2D patients by 29 and 63%, respectively.
T2D patients under treatment with glucose-lowering drugs, antihypertensive treatment as well as with statins have significantly increased ROCK activation in their circulating leukocytes along with higher phosphorylation of downstream cascade proteins despite pharmacologic treatment, along with increased plasma angiotensin II and MDA levels. ROCK inhibition might have an additional role in the prevention and treatment of T2D.
Reverse remodeling is a clinically relevant endpoint in heart failure with reduced ejection fraction (HFrEF). Rho-kinase (ROCK) signaling cascade activation correlates with cardiac remodeling and ...left ventricular (LV) systolic dysfunction in HFrEF patients. Cardiac resynchronization therapy (CRT) is effective in HFrEF, especially when there is a left bundle block, as this treatment may stimulate reverse remodeling, thereby improving quality of life and prolonging survival for patients with this severe condition. Here, we evaluate the hypothesis that ROCK activation is reduced after effective CRT in HFrEF.
ROCK activation in circulating leukocytes was evaluated in 28 HFrHF patients, using Western blot (myosin light chain phosphatase subunit 1 phosphorylation, MYPT1p/t), before and three months after initiation of CRT. LV systolic function and remodeling were assessed by echocardiography.
Three months after CRT, LV ejection fraction increased an average of 14.5% (
< 0.001) in 13 patients (responders), while no change was observed in 15 patients (non-responders). End-systolic diameter decreased 16% (
< 0.001) in responders, with no change in non-responders. ROCK activation in PBMCs decreased 66% in responders (
< 0.05) but increased 10% in non-responders (NS). LV end-diastolic diameter was also 5.2 mm larger in non-responders vs. responders (
= 0.058). LV ejection fraction, systolic diameter, and ROCK activation levels were similar in both groups at baseline.
In HFrEF patients, 3 months of effective CRT induced reverse myocardial remodeling, and ROCK activation was significantly decreased in circulating leukocytes. Thus, decreased ROCK activation in circulating leukocytes may reflect reverse cardiac remodeling in patients with heart failure.
Background
Increased Rho‐kinase activity in circulating leucocytes is observed in heart failure with reduced ejection fraction (HFrEF). However, there is little information in HFrEF regarding other ...Rho‐kinase pathway components an on the relationship between Rho‐kinase and apoptosis. Here, Rho‐kinase activation levels and phosphorylation of major downstream molecules and apoptosis levels were measured for the first time both in HFrEF patients and healthy individuals.
Methods
Cross‐sectional study comparing HFrEF patients (n = 20) and healthy controls (n = 19). Rho‐kinase activity in circulating leucocytes (peripheral blood mononuclear cells, PBMCs) was determined by myosin light chain phosphatase 1 (MYPT1) and ezrin‐radixin‐moesin (ERM) phosphorylation. Rho‐kinase cascade proteins phosphorylation p38‐MAPK, myosin light chain‐2, JAK and JNK were also analysed along with apoptosis.
Results
MYPT1 and ERM phosphorylation were significantly elevated in HFrEF patients, (3.9‐ and 4.8‐fold higher than in controls, respectively). JAK phosphorylation was significantly increased by 300% over controls. Phosphorylation of downstream molecules p38‐MAPK and myosin light chain‐2 was significantly higher by 360% and 490%, respectively, while JNK phosphorylation was reduced by 60%. Catecholamine and angiotensin II levels were significantly higher in HFrEF patients, while angiotensin‐(1‐9) levels were lower. Apoptosis in circulating leucocytes was significantly increased in HFrEF patients by 2.8‐fold compared with controls and significantly correlated with Rho‐kinase activation.
Conclusion
Rho‐kinase pathway is activated in PMBCs from HFrEF patients despite optimal treatment, and it is closely associated with neurohormonal activation and with apoptosis. ROCK cascade inhibition might induce clinical benefits in HFrEF patients, and its assessment in PMBCs could be useful to evaluate reverse remodelling and disease regression.
Big thrombus “sitting” in an atrial septal aneurysm Adauy, Julián Vega; Gabrielli, Luigi; Córdova, Samuel ...
Echocardiography (Mount Kisco, N.Y.),
September 2017, 2017-Sep, 2017-09-00, 20170901, Letnik:
34, Številka:
9
Journal Article
Recenzirano
A 79 year‐old‐man presented three episodes of upper gastrointestinal bleeding and weight loss. Endoscopy revealed bleeding and extrinsic compression at the pyloric region. Computed tomography scan ...showed a pancreatic tumor, peritoneal carcinomatosis, vascular infiltration, and incidentally found a partially calcified hypodense lesion of 35 mm in the left atrium, suggesting a myxoma or a thrombus. Echocardiography revealed moderate left atrium enlargement, dilated left atrial appendage with spontaneous echo contrast, moderate dilatation and dysfunction of the left ventricle, ejection fraction was 39%, and an atrial septal aneurysm in which a piriform, mass of 35×33×25 mm, was “sitting,” suggesting an organized thrombus.
To develop an artificial seed of sugar cane using sodium alginate and starch, it was possible to bring shoots resistance and protection in addition to a germination of 100 and 84%, respectively. In ...order to improve the technology of the artificial seed of sugarcane, two experiments were carried out to evaluate different polymer concentrations (sodium alginate and starch) and determine the maximum storage time for the artificial seed, using a completely random design, and a factorial 5x5 completely random design. The study variables were as follows: physical condition, rheological, mechanical test and seedling emergence. The results obtained have allowed to us to conclude that the best physical condition, resistance and seedling emergence, were obtained with 2% (w/v) sodium alginate and 15% (w/v) starch, corroborating that the initially proposed encapsulation is reliable for the artificial seed elaboration. The seed viability at the fifth day of elaboration was the best choice with a seedling emergence of 100 % at the 30 days of planting. Therefore, artificial seed can only be stored for five days to ensure a 100% seed germination.
Cardiac myxomas are frequently located in the left or right atria, with multiple locations being rare. We report a 59‐year‐old healthy female with 5 months of cough and exertional dyspnea. A ...transthoracic echocardiography (TTE) exhibits a 9 × 5 cm nonpedunculated tumor arising from the interatrial septum (IAS) and inhabiting both atria, but was unable to depict the relation with the IAS. Transesophageal echocardiography exposes a single tumor crossing the IAS through an ostium secundum atrial septal defect (ASD) causing right heart functional impairment. Uneventful cardiac surgery allowed complete resection of the lesion and ASD closure. Pathology reported a myxoma.
Background: Hypertrophic cardiomyopathy (HCM) is a common cause of sudden death in athletes and differentiating this condition from the nonpathological “athlete's heart” remains a challenge. The ...development of pathological left ventricular hypertrophy (LVH) is associated with left atrial (LA) dilatation and dysfunction. LA strain and strain rate by two‐dimensional (2D) speckle tracking are novel indices of LA function and might contribute to differentiate physiological from pathological LVH among athletes with underdiagnosed HCM. Methods: We evaluated 20 patients with nonobstructive HCM, 20 highly trained athletes and 20 healthy controls matched for age, gender, and body surface area. All patients underwent a transthoracic echocardiogram with evaluation of LA strain: s‐wave (LASs); and strain rate: s‐wave (LASRs) and a‐wave (LASRa). Results: LV mass index, LA volume index, and ejection fraction were comparable between patients with HCM and athletes. Patients with HCM had a significantly lower LASs (19 + 8% vs. 43 + 8%, P < 0.01), LASRs (0.7 + 0.2 s‐1 vs. 1.6 + 0.2 s‐1, P < 0.01), and LASRa (–0.8 + 0.1 s‐1 vs. –1.4 + 0.3 s‐1, P < 0.01) compared to athletes. Among hypertrophic subjects, independent predictors of hypertrophy related to HCM were LASs and E/é ratio. Conclusions: LA myocardial deformation is significantly impaired in patients with HCM compared to athletes and healthy controls. LA strain and strain rate assessed by 2D speckle tracking should be incorporated in the evaluation of trained athletes with LVH and LA dilatation.
Background The small guanosine triphosphatase Rho and its target Rho-kinase have significant roles in experimental remodeling and ventricular dysfunction, but no data are available on Rho-kinase ...activation in patients with heart failure (HF). We hypothesized that, in patients with chronic HF, Rho-kinase in circulating leukocytes is activated and related to left ventricular (LV) remodeling and dysfunction. Methods Accordingly, Rho-kinase activity, assessed by the levels of phosphorylated to total myosin light chain phosphatase 1 (MYPT1-P/T) in circulating leukocytes, and echocardiographic LV function data were compared between patients with HF New York Heart Association functional class II or III due to systolic dysfunction (n = 17), healthy controls (n = 17), and hypertensive patients without HF (n = 17). Results In the control subjects, mean MYPT1-P/T ratio was 1.2 ± 0.2 (it was similar in the hypertensive patients without HF), whereas in patients with HF, it was significantly increased by >100-fold ( P < .001). Both MYPT1-P/T and log MYPT1-P/T ratios were inversely correlated with ejection fraction ( r = −0.54, P < .03 and r = −0.86, P < .001, respectively). Furthermore, in patients with HF with LV end-diastolic diameter <60 mm, MYPT1-P/T ratio was 35.8 ± 18.1, whereas it was significantly higher in patients with LV diameter ≥60 mm ( P < .05). Conclusions Rho-Kinase activity is markedly increased in patients with stable chronic HF under optimal medical treatment, and it is associated with pathologic LV remodeling and systolic dysfunction. Mechanisms of Rho-kinase activation in patients with HF, its role in the progression of the disease, and the direct effect of Rho-kinase inhibition need further investigation.
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