Despite the big deployment of concentrating solar power (CSP) plants, their environmental evaluation is still a pending issue. In this paper, a detailed life cycle assessment (LCA) of a CSP tower ...plant with molten salts storage in a baseload configuration is carried out and compared with a reference CSP plant without storage. Results show that the plant with storage has a lower environmental impact due to the lower operational impact. The dependence on grid electricity in a CSP tower plant without storage increases its operation stage impact. The impact of the manufacturing and disposal stage is similar in both plants. When analyzed in detail, the solar field system and the thermal energy storage (TES) and heat transfer fluid (HTF) systems are the ones with higher impact. Within the storage system, the molten salts are those with higher impact. Therefore, in this study the impact of the origin of the salts is evaluated, showing that when the salts come from mines their impact is lower than when they are synthetized. Results show that storage is a key element for CSP plants not only to ensure dispatchability but also to reduce their environmental impact.
A significant increase of the electrical conductivity of PEDOT:PSS films, brought about by the addition of dimethyl sulfate (DMS, (CH3)2SO4), while preserving the films’ excellent flexibility and ...visible-light transparency, is reported. The electrical and morphological properties of the films were studied as a function of DMS concentration. At an optimal concentration of around 1:25 (DMS to PEDOT:PSS), the conductivity of the films is enhanced by a factor on the order of 1880 times that of pristine PEDOT:PSS films. Extensive spectroscopic measurements using absorbance, Raman, and FTIR techniques, as well as structural characterization by AFM microscopy, were performed. These measurements support the idea that the mechanism responsible for the conductivity enhancement is the partial replacement of the PSS− segments by SO4 −2 anionic sulfates when a small amount of DMS is added to a PEDOT:PSS solution. This mechanism is associated with an increase of doping, and this doping can be understood in the following manner: due to that the SO3 − ions of the PSS segment only carry one negative charge, it is more probable for them to create polaronic states, whereas the SO4 −2 ions are double charged, increasing the possibility of creating bipolaron carriers in the PEDOT backbone. In this way, the partial replacement of the PSS− segments by SO4 −2 ions increases the bipolaron population by an ion exchange process, and, as a consequence, the doping level is increased.
The effect of Si and Al promoted in TiO2 catalysts on both acid-base properties and 2-propanol dehydration was studied. The sol-gel method was used to prepare pure TiO2 and TiO2-Al2O3 and TiO2-SiO2 ...mixed oxides with 1%, 3% and 10% of Al2O3 or SiO2. The structure and surface characterization (XRD, TG-DTA, N2 sorption, 27Al and 19Si MAS NMR) revealed that the promoted cations were dispersed in the TiO2 lattice. The acid and basic sites density was measured by NH3-TPD and CO2-TPD. FTIR-pyridine-TPD revealed predominantly Lewis-type acidity for all these catalysts and a low presence Brønsted-type acidity was detect only for 10% SiO2 promoted catalyst. The change in the activity of 2-propanol decomposition was useful to detect the effect of type and content of cation in the acid-base properties of promoted catalysts. The acid-base molar ratio of the catalytic surface was increased as a function of content of Al and Si and it was related to the increase in the alcohols decomposition activity. Dehydration activity was more sensitive for the Si-promoted catalysts than the Al-promoted ones, showing an important role of cation coordination in the acidic and catalytic properties of these mixed oxides.
Introduction
Polyphenols have shown capacity to improve appetite sensation, leading to enhanced control of body weight. However, despite being related with hunger-related hormones, metabolic and ...mechanism are not well known.
Methods
The effectiveness of a nutraceutical composed of extract to
Lippia citriodora
and
Hibiscus sabdarrifa
(Lc-Hs) for controlling satiety and hunger was analyzed in a cross-over, placebo-controlled (Pla) clinical intervention. The study was divided in two 60-day periods separated by 30-day length wash-out period. At the end of each period, overweight and obese subjects (
n
= 33; age = 33.76 ± 12.23; BMI = 28.20 kg/m
2
± 2.47; fat mass 30.65 ± 8.39%; both sexes were proposed to eat an ad-libitum meal. Meanwhile, appetite sensation was determined by visual analog scales at different times. Moreover, blood extraction was performed to determine biochemical parameters (lipid and glucidic profile and safety parameters) and to evaluate hunger-related hormones (insulin, leptin, ghrelin, adiponectin, GLP-1 and peptide YY).
Results
A decrease in appetite sensation was observed in Lc-Hs treatment, showing higher satiety quotient (Pla = 3.36 ± 2.33%mm/kcal; Lc-Hs = 5.53 ± 2.91%mm/kcal;
p
< 0.0001). Area under the curve was higher in Pla compared to Lc-Hs during the test, from baseline to minute 240 (240 (Pla 9136.65 ± 2261.46%
x
min
−1
; Lc-Hs 8279.73 ± 2745.71%
x
min
−1
;
p
< 0.014). Energy consumption was lower for subjects treated with Lc-Hs (774.44 ± 247.77 kcal) compared to those treated with Pla (849.52 ± 246.54 kcal) (
p
< 0.004). Leptin values varied from baseline (Pla 12.36 ± 1.98 ng/mL; Lc-Hs 13.13 ± 1.99 ng/mL) to the end of the study (Pla 12.60 ± 2.02 ng/mL; Lc-Hs 12.06 ± 2.05 ng/mL;
p
< 0.047). GLP-1 values varied (
p
< 0.001) in Lc-Hs treatment from baseline (4.34 ± 0.49 ng/mL) to the end of the study (3.23 ± 0.52 ng/mL).
Conclusion
The supplementation with the Lc-Hs extract decreases appetite sensation in overweight and obese population, reducing calorie intake after an ad-libitum meal. Due to variation on hunger-related hormones and the relationship between satiety feeling, it would be interesting to develop future research focused on the variation of the hormones themselves.
Here in the results of simulation of a batch reactor in which the transesterification of triolein is carried out in presence of a heterogenous catalyst. The simulated operation conditions consisted ...in two levels of temperature (50 and 60 °C), concentration of catalyst (0.5 and 1.0 kg/m
3
) and two initial concentrations of intermediaries and final products (at 1 and 10 g), keeping the amount of triolein and methanol at 1 kg and 12 mol of alcohol per mol of triolein. For the most severe conditions and lower amount of intermediaries and product in the feedstock, the final concentration of methyl oleate was 1.45 mol/L. At similar conditions of operation of reactor, the effect of reducing the concentration of catalyst was the factor that affected mainly the production of methyl oleate (1.41 mol/L), followed by the effect of temperature (1.44 mol/L of methyl oleate), while no appreciable effect on biodiesel production was observed by increasing the concentration of intermediaries and products in the feedstock. The developed reactor model predicted accordingly the profiles of viscosity and density which are necessary to the mechanical design of reactor.
Bacterial Shiga-like toxins are virulence factors that constitute a significant public health threat worldwide, and the plant toxin ricin is a potential bioterror weapon. To gain access to their ...cytosolic target, ribosomal RNA, these toxins follow the retrograde transport route from the plasma membrane to the endoplasmic reticulum, via endosomes and the Golgi apparatus. Here, we used high-throughput screening to identify small molecule inhibitors that protect cells from ricin and Shiga-like toxins. We identified two compounds that selectively block retrograde toxin trafficking at the early endosome-TGN interface, without affecting compartment morphology, endogenous retrograde cargos, or other trafficking steps, demonstrating an unexpected degree of selectivity and lack of toxicity. In mice, one compound clearly protects from lethal nasal exposure to ricin. Our work discovers the first small molecule that shows efficacy against ricin in animal experiments and identifies the retrograde route as a potential therapeutic target.
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► Identification of two toxin inhibitors by cell-based high-throughput screening ► Cells are protected against the plant toxin ricin and bacterial Shiga-like toxins ► Inhibitors selectively block toxin trafficking at endosome-TGN interface ► One compound protects mice from lethal nasal challenge with ricin
In this study, a new series of more than 60 quinoline derivatives has been synthesized and evaluated against Mycobacterium tuberculosis (H37Rv). Apart from the SAR exploration around the initial ...hits, the optimization process focused on the improvement of the physicochemical properties, cytotoxicity, and metabolic stability of the series. The best compounds obtained exhibited MIC values in the low micromolar range, excellent intracellular antimycobacterial activity, and an improved physicochemical profile without cytotoxic effects. Further investigation revealed that the amide bond was the source for the poor blood stability observed, while some of the compounds exhibited hERG affinity. Compound 83 which contains a benzoxazole ring instead of the amide group was found to be a good alternative, with good blood stability and no hERG affinity, providing new opportunities for the series. Overall, the obtained results suggest that further optimization of solubility and microsomal stability of the series could provide a strong lead for a new anti-TB drug development program.
The high intermittency of solar energy is still a challenge yet to be overcome. The use of thermal storage has proven to be a good option, with phase change materials (PCM) as very promising ...candidates. Nevertheless, PCM compounds have typically poor thermal conductivity, reducing their attractiveness for commercial uses. This paper demonstrates the viability of increasing the PCM effective thermal conductivity to industrial required values (around 4 W/m·K) by using metal wool infiltrated into the resin under vacuum conditions. To achieve this result, the authors used an inert resin, decoupling the specific PCM material selection from the enhancement effect of the metal wools. To ensure proper behavior of the metal wool under standard industrial environments at a broad range of temperatures, a set of analyses were performed at high temperatures and an inert atmosphere, presenting a thorough analysis of the obtained results.
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