Calcium-dependent binding between calmodulin and lysozyme

AbstractCalmodulin, an acidic protein that binds calcium with high affinity, has multiple roles in the activation of many enzymes involved in cellular regulation of eukaryotes. In this study we show that calmodulin binding to hen egg-white lysozyme, in a Ca2+-dependent way, was observed using electroblots incubated with biotinylated calmodulin and detected with avidin-alkaline phosphatase or for affinity chromatography on a gel calmodulin column. Antimicrobial activity of lysozyme was not modified in the presence of Ca2+-calmodulin

Permeabilizing action of an antimicrobial lactoferricin-derived peptide on bacterial and artificial membranes

AbstractA synthetic peptide (23 residues) that includes the antibacterial and lipopolysaccharide-binding regions of human lactoferricin, an antimicrobial sequence of lactoferrin, was used to study its action on cytoplasmic membrane of Escherichia coli 0111 and E. coli phospholipid vesicles. The peptide caused a depolarization of the bacterial cytoplasmic membrane, loss of the pH gradient, and a bactericidal effect on E. coli. Similarly, the binding of the peptide to liposomes dissipated previously created transmembrane electrical and pH gradients. The dramatic consequences of the transmembrane ion flux during the peptide exposure indicate that the adverse effect on bacterial cells occurs at the bacterial inner membrane

Catalysts based on Co-Birnessite and Co-Todorokite for the efficient production of hydrogen by ethanol steam reforming

[EN] Two structured manganese oxides (Birnessite and Todorokite) containing Co have been studied in the steam reforming of ethanol. It has been found that both materials are active in the hydrogen production, exhibiting high values of conversion of ethanol and selectivities to hydrogen (100% and 70%, respectively). The best results have been obtained with the catalyst based on Todorokite material. Characterization by DRX, BET area, TPR and TEM has allowed to find that the excellent performance exhibited by this material could be attributed to the lower size of the Co metallic particles present in this sample (6 nm vs 12 nm in Birnessite). This lower size could be related to the especial microporous structure of Todorokite precursor, which could provide high-quality positions for the stabilization of the Co metal particles during calcination and reduction steps. Catalytic deactivation has also been considered. Deactivation was found higher for Todorokite-based catalyst, which presented the largest amount of deposited carbon (26.2 wt% for Co-TOD vs 10.6 wt% for Co-BIR). On the other hand, the degree of metal sintering was found similar in both catalysts. Therefore, the deactivation of the catalysts has been attributed primarily to the deposition of coke. The results presented here show that it is possible to prepare new catalysts based on manganese oxides with Birnessite and Todorokite structure and promoted with Co with high catalytic performance in the steam reforming of ethanol. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.The doctor Javier Francisco Da Costa Serra acknowledges the CSIC for granted the scholarship predoctoral-JAE-CSIC. Moreover, Electronic Microscopy Service of UPV for TEM images.Da Costa Serra, JF.; Chica, A. (2018). Catalysts based on Co-Birnessite and Co-Todorokite for the efficient production of hydrogen by ethanol steam reforming. International Journal of Hydrogen Energy. 43(35):16859-16865. https://doi.org/10.1016/j.ijhydene.2017.12.114S1685916865433

New Catalysts based on Ni-Birnessite and Ni-Todorokite for the Efficient Production of Hydrogen by Bioethanol Steam Reforming

Catalytic steam reforming of bioethanol seems to be a promise option to produce renewable hydrogen; however efficient catalysts are still under development. Recently, manganese oxide based materials (MO) are the subject of intense research as low cost, efficient, and environmentally friendly catalysts. Among them MO with layer and tunnel structure have received significant attention due to their excellent catalytic activity. Specifically, we have explored the catalytic performance of two MO containing Ni (Birnessite and Todorokite). We find that both materials are highly active and selective to produce hydrogen by steam reforming of bioethanol. Their characterization by DRX, BET area, TPR, and TEM, has allowed to find that the excellent performance exhibited by these materials could be attributed to the especial structure of these MO, which would provide high-quality positions for the stabilization of the Ni metal particles.Fuertes, A.; Da Costa Serra, JF.; Chica, A. (2012). New Catalysts based on Ni-Birnessite and Ni-Todorokite for the Efficient Production of Hydrogen by Bioethanol Steam Reforming. Energy Procedia. 29:181-191. doi:10.1016/j.egypro.2012.09.023S1811912

Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Advanced Preparative Strategies for Activated Carbons Designed for the Adsorptive Storage of Hydrogen

Since air quality is a major public health concern, especially in urban areas, the use of alternative fuels for vehicular applications has been strongly encouraged. Of these fuels, hydrogen is the only one that can produce zero emission through fuel cells. However, the storage of such a very light and highly combustible gas has yet to be solved. Only adsorption storage is discussed in the present paper. It should be recalled that no material has been capable of meeting the recommended targets to date. Recent progresses in preparing suitable carbon structures for hydrogen storage are described, and new routes for characterising and correspondingly improving the micropore texture are explored