Low-molecular-weight heparin represent a significant advancement in anticoagulant therapy with enoxaparin being a prominent example obtained exclusively through the fragmentation of porcine ...intestinal heparin. However, escalating demand and limited resources have raised concerns about enoxaparin supplementation. The current challenge involves exploring alternative heparin sources for large-scale enoxaparin production with bovine intestinal heparin emerging as a promising option. Our study demonstrates that enoxaparin derived from the available bovine heparin preparation differs significantly from the reference compound. Yet, the implementation of a straightforward purification step yields a preparation termed “high-anticoagulant bovine heparin”. Fragmentation of this purified product through β-elimination produces enoxaparin akin to the standard from a porcine origin. To ensure physicochemical similarity, we employed various spectroscopic, enzymatic, and chromatographic tests to compare the new bovine-derived enoxaparin with the original porcine compound. Biological activity was confirmed through in vitro coagulation assays and assessments using an animal model of venous thrombosis. Our study affirms that the β-elimination reaction cleaves the bovine heparin chain without preferential breaks in regions with different sulfation patterns. Additionally, we scrutinized decasaccharides purified from enoxaparin preparations, providing a comprehensive demonstration of the similarity between products obtained from porcine and bovine heparin. In summary, our findings indicate that an enoxaparin equivalent to the original porcine-derived product can be derived from bovine heparin, given that the starting material undergoes a simple purification step.
•Fe-containing carbon catalysts for FTS prepared by distinct routes.•Effects of the FTS reaction temperature and pressure were examined.•Using ferrocene by sol-gel method, syngas is converted to C10+ ...hydrocarbons.•Chemical modification of ferrocene enables Fe nanoparticles on carbon actives in WGS.•Synergy of magnetite, Fe-doped nitrogen and the iron carbides determine performance.
Four different preparation routes were applied to obtain Fe-containing carbon catalysts for Fischer Tropsch Synthesis (FTS) including copolymer assisted co-precipitation of iron precursor, chemical modification of ferrocene, sol-gel and wetness impregnation of iron on polymeric carbon. The effects of the FTS reaction temperature and pressure were also examined. Using ferrocene as a starting precursor and applying sol-gel method to prepare the solid, the syngas is readily converted to C10+ hydrocarbons with a conversion of up to 56% and a productivity of 34mg hydrocarbon.gcat−1.h−1 at 240°C and 20atm. Impregnation method gave a Fe/C based catalyst with the highest exposure of active sites, including surface Fe3+ and Fe2+ redox sites with great properties in FTS. Chemical modification of ferrocene route enables the formation of hematite and maghemite nanoparticles on carbon, which were in situ reduced to magnetite and iron carbides, being the latter mostly active for the water gas shift reaction. It is found that copolymer assisted co-precipitation of ferrocene facilitates the production of large crystals of magnetite, which suffered from sintering and coking exhibiting low performance in FTS. Among these methods, sol-gel based catalyst proved to have superior performance due to the good dispersion of Fe, stable magnetite and iron carbide and Fe-doped nitrogen carbon phases production. Based on spent catalysts characterizations, the synergetic effect between magnetite and the iron carbides phases in the sol-gel based catalyst plays an important role in heavy hydrocarbon formation.
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•Metal-containing titanate nanotubes had suitable pore-structure and surface acidity.•PtOx and chlorined-Pt species dispersed on the alkali trititanate nanotube phase.•Catalytic ...activity affected by surface and structural properties.•Leaching of Co and Ni species caused the deactivation of the CTNT and NTNT catalysts.•PTNT exhibited high stability during solkeltal production.
Pt-containing titanate nanotubes (PTNT) catalyst had PtOx and chlorined-Pt species dispersed on the alkali trititanate nanotube phase (TNT). This solid was morphologically and structurally stable during glycerol acetalization of glycerol with acetone. In contrast, a significant transformation of Ni2+ and Co3+/Co2+ surface species dispersed on TNT provoked morphological, textural and surface changes affecting the catalytic performance of these samples, as observed with the help of HRTEM, XPS, Raman and textural properties measurements. Leaching of Co and Ni species was identified as the main mechanism for the deactivation respectively on Co-containing titanate nanotubes (CTNT) and Ni-containing titanate nanotube (NTNT) catalysts. On the contrary, PTNT performed very well giving rise to 28% of conversion and 11% selectivity to solketal over three reaction cycles of 24 h. This was thanked to the suitable tuning of pore-structure and proper surface acidity of PTNT, resulting in a stable solid for the reaction.
•A new test is proposed to assess energy savings on the tire-pavement interaction.•Lab data were successfully analyzed with two data mining techniques (ANN and SVM).•ANN presented the best ...performance for energy consumption estimation.•Prediction quality can be maintained for models with three or more input parameters.•The main parameters governing the energy consumption are speed and surface texture.
The energy or fuel consumption of the millions of vehicles that daily operate in road pavements has a significant economic and environmental impact on the use phase of road infrastructures regarding their life cycle analysis. Therefore, new solutions should be studied to reduce the vehicles energy consumption, namely due to the tire-pavement interaction, and contribute towards the sustainable development. This study aims at estimating the energy consumption due to the rolling resistance of tires moving over pavements with distinct surface characteristics. Thus, different types of asphalt mixtures were used in the surface course to determine the main parameters influencing the energy consumption. A laboratory scale prototype was developed explicitly for this evaluation. Data mining techniques were used to analyze the experimental results due to the complex correlation between the data collected during the tests, providing meaningful results. In particular, the artificial neural network allowed to obtain models with excellent capacity to estimate energy consumption. A sensitive analysis was carried out with a five input parameter model, which showed that the main parameters controlling the energy consumption are the vehicle speed and the mean texture depth.
The long term and complex nature of Chagas disease in humans has restricted studies on vaccine feasibility. Animal models also have limitations due to technical difficulties in monitoring the ...extremely low parasite burden that is characteristic of chronic stage infections. Advances in imaging technology offer alternative approaches that circumvent these problems. Here, we describe the use of highly sensitive whole body in vivo imaging to assess the efficacy of recombinant viral vector vaccines and benznidazole-cured infections to protect mice from challenge with Trypanosoma cruzi.
Mice were infected with T. cruzi strains modified to express a red-shifted luciferase reporter. Using bioluminescence imaging, we assessed the degree of immunity to re-infection conferred after benznidazole-cure. Those infected for 14 days or more, prior to the onset of benznidazole treatment, were highly protected from challenge with both homologous and heterologous strains. There was a >99% reduction in parasite burden, with parasites frequently undetectable after homologous challenge. This level of protection was considerably greater than that achieved with recombinant vaccines. It was also independent of the route of infection or size of the challenge inoculum, and was long-lasting, with no significant diminution in immunity after almost a year. When the primary infection was benznidazole-treated after 4 days (before completion of the first cycle of intracellular infection), the degree of protection was much reduced, an outcome associated with a minimal T. cruzi-specific IFN-γ+ T cell response.
Our findings suggest that a protective Chagas disease vaccine must have the ability to eliminate parasites before they reach organs/tissues, such as the GI tract, where once established, they become largely refractory to the induced immune response.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Mesoporous mixed oxides supports modified by Pt or Ru addition.•MgO, ZrO2, CeO2 and La2O3 promoters added to alumina support.•Distinct behaviours were observed when Ru or Pt was dispersed on these ...solids.•Pt/CeO2–Al2O3 showed high catalytic performance compared to the other solids.
Mesoporous mixed oxides supports were impregnated with solutions of Pt or Ru compounds. The catalytic performance and stability were evaluated in dry reforming of methane. The catalysts were characterized by X-ray diffraction (XRD), nitrogen adsorption–desorption isotherms, temperature programmed reduction (TPR), High-resolution transmission electron microscopy (HRTEM) and Transmission electron microscopy (TEM) analyses and Raman spectroscopy. Promoters such as MgO, ZrO2, CeO2 and La2O3 were added to alumina support and exhibited distinct behaviour, when Ru or Pt was dispersed on these solids. Catalysts based on Pt-containing CeO2–Al2O3 showed a relatively high catalytic activity and stability compared to the other solids. The influences of the temperature and CH4/CO2 on the catalytic behaviour of the most active solids were also studied. The coking takes place due to carbonaceous deposition, but no significant loss of activity was observed during 24h for some catalysts, which suggest the carbon species formed did not damage the solid.
We evaluated the effects of feeding 6%, 12% or 18% crude glycerin, containing 80.5% glycerol, on testicular histomorphometry and markers of oxidative stress and on plasma testosterone concentrations ...in lambs. Body weight, testicular biometric measurements, gonadosomatic index and net weight of the testicles were higher for the treated groups (P <0.05) compared with a control group that did not receive dietary glycerin. The mean total length of seminiferous tubules was higher in the 6% group (P <0.05), while the mean total tubular and seminiferous epithelium volumes increased in all treated groups (P <0.05). The volume of Leydig cells increased in the 12% group, while their number per gram of testicle decreased (P <0.05). There was a decrease in mean nuclear diameter and mean volume of Leydig cells, and an increase in the mean number of these cells per gram of testicle, in the 18% group (P <0.05). Plasma testosterone concentrations were unaffected. There was desquamation of seminiferous epithelium and vacuolation of Sertoli cells in the treated groups. Variable degrees of spermatocyte necrosis and the presence of giant cells were seen in all groups and there was intense vacuolation of Sertoli cells in the 12% and 18% groups. Superoxide dismutase and catalase production increased most in the 12% and 18% groups (P <0.05), while glutathione production was higher in the 18% group (P <0.05). Mean nitric oxide concentration decreased in all treated groups (P <0.05), while malondialdehyde production was higher in the 18% group than in the control and 6% groups (P <0.05). We conclude that the inclusion of 6% glycerin in the diet of lambs results in changes in testicular morphology that have been previously associated with improved reproductive function, but without evidence of oxidative stress.
Oxides with good catalytic performances and more selectivity to valuable chemicals attract numerous research interests for the oxidation of hydrocarbon fuels. Taking advantage of the nanocasting ...route, CeFe-based nanocomposites were prepared and characterized to achieve superior stability in the oxidation of cyclic compounds. Adding a third metal (Me = Ni2+, Mn2+/Mn3+ or Co2+/Co3+) to the CeFe-based oxide helped the formation of Ce3+/Ce4+, Fe2+/Fe3+ and active couples in the ternary nanocomposites. The solids having a spherical morphology and good textural properties enabled the formation of promising ternary oxide catalysts for the oxidation of ethylbenzene compared with those of binary and single monoxide nanocomposites. The close contact among the Ce3+/Ce4+ and Fe2+/Fe3+ pairs with Ni2+ species provided the formation of a highly stable CeFeNi catalyst with enhanced performance in the oxidation of cyclic compounds such as ethylbenzene, styrene and benzyl alcohol substrates.
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