Carrageenan from Chondracanthus Chamissoi Algae: Extraction process and experimental evaluation as green corrosion inhibitor for P22 steel in HCl

In this study, the extraction yield of carrageenan from the algae Chondracanthus Chamissoi and its efficiency as an ecological corrosion inhibitor for P22 steel in 1 M HCl at 65°C were evaluated. The extraction of carrageenan from the algae Chondracanthus chamissoi was carried out in cold water at 25°C (CC) and hot water at 80°C (HC), with different degreasing stages prior to the extraction (0, 1 and 2 stages). The codes of the six samples of carrageenan obtained were selected in terms of the production temperature and degreasing stages as: CC-0, CC-1, CC-2, HC-0, HC-1 and HC-2. All the carrageenan samples were characterized using: Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive spectrum. The CC shows crystallinity and is mainly composed of κ-carrageenan in the presence of KCl, NaCl and K3Na(SO4)2; while the degreasing stages reduce the content of KCl and NaCl. The HC presents an amorphous structure composed of κ/ι carrageenans. The highest carrageenan extraction yielded in cold water was 21.43%, without the degreasing stage (CC-0); while, the highest carrageenan extraction yielded in hot water was 28.96% with 2 degreasing stages (HC-2). The inhibition performance was investigated using gravimetric analysis, potentiodynamic polarization, linear polarization resistance, electrochemical impedance spectroscopy and electrochemical frequency modulation. The experimental results demonstrated that all six carrageenan inhibitors act as good corrosion inhibitors for P22 steel in 1 M HCl at 65°C. However, the CC-0 presented the maximum corrosion inhibition efficiency (IEc) of 85.53% (EIS technique). In the HC, the degrease does not significantly affect IEc, allows to obtain 82.56% without degrease (EIS technique). Based on the results obtained, the extraction CC-0 and HC-0 in the same extraction process, allows to obtain a semi-refined, economical carrageenan, with a total carrageenan yield of 45.91%, and with a high IEc.Fil: Zavaleta Gutiérrez, N.. Universidad Nacional de Trujillo.; PerúFil: Alvarado Loyola, L.. Universidad Nacional de Trujillo.; PerúFil: Angelats Silva, L.. Universidad Privada Atenor Orrego; PerúFil: Ñique Gutierrez, N.. Universidad Nacional de Trujillo.; PerúFil: Duffó, Gustavo Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentina. Universidad Nacional de San Martín; Argentin

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

HETEROGENEOUS AUSTENITE GRAIN GROWTH IN MARTENSITIC 9Cr STEEL: COUPLED INFLUENCE OF THE INITIAL METALLURGICAL STATE AND THE HEATING RATE

The coupled influence of the initial metallurgical state and the heating rate to austenite on the occurrence of heterogeneous grain growth during austenitisation of an ASTM A213‐T91 steel has been studied. To that aim, two-step thermal cycles were designed. In the first step, different starting metallurgical conditions were obtained by treating the as received material at 780°C for increasing times up to 6 h. In the second step, in situ austenitisation was performed by heating to austenite at rates of 1, 30 and 50°C s−1 and then holding at 1050°C for 30’. Two types of austenite grain structures were obtained after austenitisation, namely, homogeneous and heterogeneous. The homogeneous structure was characterised by a smooth size distribution of approximately equiaxed, normally grown grains. The heterogeneous structure, instead, exhibited the exaggerated growth of a few austenite grains embedded in a small to medium sized matrix. For the 1°C s−1 heating rate and all of the initial metallurgical states, only homogeneous grain growth was observed, whereas for the 50°C s−1 heating rate only heterogeneous grain growth was observed regardless the starting metallurgical condition. Instead, the occurrence of homogeneous or heterogeneous grain growth after heating at 30°C s−1 was observed to be a function of the time of previous tempering. Some explanations of the phenomenon are advanced taking into account the precipitation state of second phasesfinancial support of National Science and Technology Agency from Argentina in the form of PICT 2005 Nº 33325 contract. CC, CGDA and ITC acknowledge financial support of the Spanish Ministerio de Economia e Innovación in the form of a Coordinate Project (ENE2009-13766-C04-01) in the Energy Area of Plan Nacional 2009Peer reviewe

Heterogeneous austenite grain growth in ASTM A213 Grade T91 steels: Analysis of austenitic grain size distribution using kernel density estimation methodology

The present work studies, using statistical methods, the features of austenite grain size distributions (AGSDs) obtained in an ASTM A213-T91 steel by applying two-step thermal cycles, namely, thermal treatment at tempering temperature +'in situ' austenitisation. Changes in AGSD were produced by varying the holding time at tempering temperature and the heating rate to austenite. The application of different thermal cycle conditions induced two main characteristics in the AGSDs, i.e. the growth of a few very large grains in a matrix of small to medium sized grains, that is, heterogeneous grain size, and a bimodal grain size distribution in that matrix. Statistical techniques were used to describe the resulting AGSDs and to investigate a possible correlation between bimodality and heterogeneity. The characterisations have been carried out using the kernel density estimation (KDE) technique to compute the underlying statistical distribution, and then applying a significance test able to assess whether or not bimodality, if detected with KDE, is statistically significant. Results indicate that bimodality is evidenced for the higher heating rates to austenite and is very likely related to the development of the heterogeneous grain size structure. © 2014 Institute of Materials, Minerals and Mining.NZG, MIL and CAD acknowledge the financial support of the National Science and Technology Agency from Argentina in the form of PICT 2005 no. 33325 contract. ITC, CC and CGDA acknowledge the financial support of the Spanish Ministerio de Economia e Innovacio´n in the form of a Coordinate Project (ENE2009-13766-C04-01) in the Energy Area of Plan Nacional 2009.Peer Reviewe

Snake Venomics of the Central American Rattlesnake Crotalus simus and the South American Crotalus durissus Complex Points to Neurotoxicity as an Adaptive Paedomorphic Trend along Crotalus Dispersal in South America

We report a comparative venomic and antivenomic characterization of the venoms of newborn and adult specimens of the Central American rattlesnake, Crotalus simus, and of the subspecies cumanensis, durissus, ruruima, and terrificus of South American Crotalus durissus. Neonate and adult C. simus share about 50% of their venom proteome. The venom proteome of 6-week-old C. simus is predominantly made of the neurotoxic heterodimeric phospholipase A2 (PLA2 crotoxin) (55.9%) and serine proteinases (36%), whereas snake venom Zn2+-metalloproteinases (SVMPs), exclusively of class PIII, represent only 2% of the total venom proteins. In marked contrast, venom from adult C. simus comprises toxins from 7 protein families. A large proportion (71.7%) of these toxins are SVMPs, two-thirds of which belong to the PIII class. These toxin profiles correlate well with the overall biochemical and pharmacological features of venoms from adult (hemorrhagic) and newborn (neurotoxic) C. simus specimens. The venoms of the South American Crotalus subspecies belong to one of two distinct phenotypes. C. d. cumanensis exhibits high levels of SVMPs and low lethal potency (LD50), whereas C. d. subspecies terrificus, ruruima, and durissus have low SVMP activity and high neurotoxicity to mice. Their overall toxin compositions explain the outcome of envenomation by these species. Further, in all C. simus and C. durissus venoms, the concentration of neurotoxins (crotoxin and crotamine) is directly related with lethal activity, whereas lethality and metalloproteinase activity show an inverse relationship. The similar venom toxin profiles of newborn C. simus and adult C. durissus terrificus, ruruima, and durissus subspecies strongly suggests that the South American taxa have retained juvenile venom characteristics in the adult form (paedomorphism) along their North−South stepping-stone dispersal. The driving force behind paedomorphism is often competition or predation pressure. The increased concentration of the neurotoxins crotoxin and crotamine in South American rattlesnake venoms strongly argues that the gain of neurotoxicity and lethal venom activities to mammals may have represented the key axis along which overall venom toxicity has evolved during Crotalus durissus invasion of South America. The paedomorphic trend is supported by a decreasing LNC (lethal neurotoxicity coefficient, defined as the ratio between the average LD50 of the venom and the crotoxin + crotamine concentration) along the North−South axis, coincident with the evolutionary dispersal pattern of the Neotropical rattlesnakes. The indistinguisable immunoreactivity patterns of Costa Rican and Venezuelan polyvalent antivenoms toward C. simus and C. durissus venoms strongly suggest the possibility of using these antivenoms indistinctly for the management of snakebites by adult C. simus and by certain C. d. cumanensis populations exhibiting a hemorrhagic venom phenotype. The antivenomic results also explain why the antivenoms effectively neutralize the hemorrhagic activity of adult C. simus venoms but does not protect against adult C. durissus sp. and newborn C. simus envenomations. The identification of evolutionary trends among tropical Crotalus, as reported here, may have an impact in defining the mixture of venoms for immunization to produce an effective pan-American anti-Crotalus antivenom.Ministerio de Educación y Ciencia/[BFU2007-6156]//EspañaUniversidad de Costa Rica/[741-A7-611]/UCR/Costa RicaPrograma Iberoamericano de Ciencia y Tecnología para el Desarrollo/206AC0281/CYTED/EspañaAcciones Integradas/2006CR001//Consejo Superior de Investigaciones Científicas/[2007CR0004]/CRUSA-CSIC/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP