Brazil unwisely gives pesticides a free pass Coelho, Felipe E A; Lopes, Lara C; Cavalcante, Raquel M S ...
Science (American Association for the Advancement of Science),
08/2019, Letnik:
365, Številka:
6453
Journal Article
Micelles have aroused interest due to their ability to assist in the transport of poorly soluble drugs. In this study the mixture of copolymers F127/E45S8 in different proportions (F/ES 30/70, 50/50 ...and 70/30) was performed to improve the bioavailability of griseofulvin and quercetin. The results of cytotoxicity (MTT assay) revealed that the copolymers F127 and E45S8 had considerable biocompatibility and did not affect the metabolism of human neutrophils. The binary systems were also evaluated by critical micellar concentration (CMC) and thermoresponsive behavior. The CMC values were intermediate to those of the isolated copolymers. The systems maintained the thermoresponsive properties present in F127 making the systems interesting for subcutaneous administration. The systems presented small size, an average range in size from 17 to 38 nm, and the samples prepared with higher hydrophobic proportion presented more uniform sizes. Results suggest stability and the increasing of the nanosystems circulation time. The F/ES 30/70 system has polydispersity smaller than 0.1 and showed an increase of 129 times for quercetin solubility. Thus, it is possible to consider F127/E45S8 micelles as potential nanosystems for poorly soluble drug delivery.
The aims of this study were to test the antifungal activity, toxicity and chemical composition of essential oil from C. sativum L. fruits. The essential oil, obtained by hydro-distillation, was ...analyzed by gas chromatography/mass spectroscopy. Linalool was the main constituent (58.22%). The oil was considered bioactive, showing an LC₅₀ value of 23 μg/mL in the Artemia salina lethality test. The antifungal activity was evaluated against Microsporum canis and Candida spp. by the agar-well diffusion method and the minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC) were established by the broth microdilution method. The essential oil induced growth inhibition zones of 28 ± 5.42 and 9.25 ± 0.5 for M. canis and Candida spp. respectively. The MICs and MFCs for M. canis strains ranged from 78 to 620 and 150 to 1,250 μg/mL, and the MICs and MFCs for Candida spp strains ranged from 310 to 620 and 620 to 1,250 μg/mL, respectively. C. sativum essential oil is active in vitro against M. canis and Candida spp. demonstrating good antifungal activity.
Thermo responsive copolymers were synthesized by radical polymerization of the N-isopropylacrylamide (NIPAm) onto galactomannan (GM) chain. All copolymers showed thermal responsiveness and a critical ...aggregation concentration (CAC) at 25 °C greater than at 50 °C. Below the lower critical solution temperature (LCST), copolymer nanoparticles presented sizes between 16 and 50 nm, whereas above LCST, they aggregate, presenting sizes in the range 145.8–194.0 nm, depending on NIPAm/GM molar ratio. Amphotericin-B (AmB) was encapsulated in the copolymer nanoparticles with encapsulation efficiency of 41.4 ± 2.76% and 69.0 ± 2.92% respectively for CP1 and CP2. In vitro AmB delivery from the CP1 nanoparticles was found to exhibit controlled release profile. Hemolysis assay was carried out using erythrocytes cells and samples of AmB loaded copolymer nanoparticles (CP1-AmB), unloaded copolymer nanoparticles (CP1) and commercial AmB were evaluated. Unloaded copolymer nanoparticles show hemocompatibility while the percentage of hemolysis of erythrocytes cells for CP1-AmB sample was 8.7 times lower than that observed for commercial AmB. CP1-AmB showed similar minimum inhibitory concentration (MIC) as commercial AmB, in four Candida albicans strains. As CP1-AmB nanoparticle show better hemocompatibility than commercial AmB, this thermo responsive copolymer shows potential as AmB nanocarrier device to be used in fungal infection.
Ephedrines are widely used in therapy. Because of their stimulant properties, these substances are relevant in different forensic fields. At present, the state of the art for ephedrines ...quantification relay based on a liquid chromatography mass spectrometry, mainly because of the dilute-and-shoot approach. Notwithstanding, several gas chromatography based methods have already been described, all of them include cleanup steps, with the potential disadvantage of incurring errors and increasing the workload. In this paper, a straightforward method for ephedrine quantification based on gas chromatographic mass spectrometry, without cleanup and based on Doehlert matrix optimization is presented. Only 10 µL of a urine sample is necessary and for N-methyl-N-(trimethylsilyl)trifluoroacetamide/N-methyl-bis-trifluoracetamide derivatives, the intermediate precision was 2.77% for ephedrine, 9.20% for cathine, 8.29% for norephedrine and 4.27% for pseudoephedrine. The limit of detection was 20 ng mL-1 for ephedrine, 30 ng mL-1 for cathine and 40 ng mL-1 for norephedrine and pseudoephedrine.
Aging leads to several anatomical and functional deficits in circadian timing system. In previous works, we observed morphological alterations with age in hypothalamic suprachiasmatic nuclei, one ...central component of this system. However, there are few data regarding aging effects on other central components of this system, such as thalamic intergeniculate leaflet (IGL). In this context, we studied possible age-related alterations in neurochemical components and retinal projections of rat IGL. For this goal, young (3 months), adult (13 months), and aged (23 months) Wistar rats were submitted to an intraocular injection of neural tracer, cholera toxin subunit b (CTb), 5 days before a tissue fixation process by paraformaldehyde perfusion. Optical density measurements and cell count were performed at digital pictures of brain tissue slices processed by immunostaining for glutamic acid decarboxylase (GAD), enkephalin (ENK), neuropeptide Y (NPY) and CTb, characteristic markers of IGL and its retinal terminals. We found a significant age-related loss in NPY immunoreactive neurons, but not in immunoreactivity to GAD and ENK. We also found a decline of retinal projections to IGL with age. We conclude aging impairs both a photic environmental clue afferent to IGL and a neurochemical expression which has an important modulatory circadian function, providing strong anatomical correlates to functional deficits of the aged biological clock.
•Ethanol production process alternatives are simulated in Aspen HYSYS®.•Two alternative fermentation technologies: low temperature and extractive.•One alternative distillation technology: double ...effect.•Their combinations are technically and economically evaluated.•Possible ethanol price reductions of up to 5% can be achieved.
The intensification of climate change and other phenomena associated with the growing pollution of the planet have increasingly highlighted the need for energy sources that are less harmful to the environment. There is currently a strong trend towards the substitution of non-renewable and highly polluting energy sources, such as petroleum derivatives, by renewable sources, from the use of biomass, for example. Sugarcane is a widely used biomass for ethanol production in Brazil, which is the second largest ethanol producer in the world. Although well established in the country, ethanol production is very complex and process alternatives are continually being developed to make it more efficient. This work aims to simulate the fermentation and distillation stages of the ethanol production process from sugarcane juice, considering both the conventional route and alternative technologies, and compare them through an integrated economic analysis. In the simulations, the yeast growth rate in the fermenter was considered through the creation of a solid pseudocomponent, which is a differential of this work. For fermentation, the conventional route was compared with Low Temperature Fermentation and Vacuum Extractive Fermentation. For distillation, besides the conventional process, Double Effect Distillation was also analyzed. It was concluded that the process designs of Low Temperature Fermentation + Conventional Distillation and Vacuum Extractive Fermentation + Double Effect Distillation are economically advantageous when compared to the conventional one, with annual net profits up to 31.6% higher, showing the possibility of obtaining a more efficient and profitable process, or a reduction of up to 5% in the ethanol price through the implementation of these alternative technologies.
Microbiological processes were used for chitin and chitosan production with Cunninghamella elegans UCP/WFCC 0542 grown in different concentrations of two agro-industrial wastes, corn steep liquor ...(CSL) and cassava wastewater (CW) established using a 2² full factorial design. The polysaccharides were extracted by alkali-acid treatment and characterized by infrared spectroscopy, viscosity, thermal analysis, elemental analysis, scanning electron microscopy and X-ray diffraction. The cytotoxicity of chitosan was evaluated for signs of vascular change on the chorioallantoic membrane of chicken eggs. The highest biomass (9.93 g/L) was obtained in trial 3 (5% CW, 8% CSL), the greatest chitin and chitosan yields were 89.39 mg/g and 57.82 mg/g, respectively, and both were obtained in trial 2 (10% CW, 4% CSL). Chitin and chitosan showed a degree of deacetylation of 40.98% and 88.24%, and a crystalline index of 35.80% and 23.82%, respectively, and chitosan showed low molecular weight (LMW 5.2 × 10³ Da). Chitin and chitosan can be considered non-irritating, due to the fact they do not promote vascular change. It was demonstrated that CSL and CW are effective renewable agroindustrial alternative substrates for the production of chitin and chitosan.
•Three non-conventional supercritical biodiesel production processes are simulated.•Triacetin and glycerol dicarbonate are produced as by-products instead of glycerol.•Route 1 proved feasible in ...every scenario and is the less energy intensive route.•Route 2 demands 3–4 times more energy and was not able to meet the specifications.•Route 3 is also feasible, but some care is needed in the final purification step.
The conventional chemical route for biodiesel production is transesterification, which is carried out on industry via homogeneous alkaline catalysis. Although several alternative technologies have been studied to make transesterification more competitive, none of them, so far, has been interesting at commercial level. One of the drawbacks of transesterification is the generation of glycerol, which must be removed and whose excess demand makes it less profitable. Therefore, a possible solution would be to explore industrial processes that generate by-products other than glycerol, which could add value to the process. In this article, simulations of three “non-conventional” supercritical routes for industrial biodiesel production were carried out: interesterification with methyl acetate (Route 1); reaction with acetic acid followed by esterification with methanol (Route 2); and reaction with dimethyl carbonate (Route 3). As the main reactions occur at supercritical state, catalysts are not required and the purification steps are simpler than for the conventional technology. Routes 1 and 3 proved to be technically feasible. The first one consumes only 7.1–8.5% of the energy that will be produced as biofuel, while the second one consumes 8.8–10.4%. The incorporation of the by-products - triacetin and glycerol dicarbonate - in the final fuel was also evaluated and proved to be a possible alternative. Route 2, however, was not able to provide biodiesel meeting the specifications (high acidity), and demands three to four times more energy than the other routes. So, it cannot be considered technically feasible at this level and will require further development.
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