Ultrastable Y (USY) zeolite remains the most important component in catalysts for converting oil fractions into gasoline. Usually, USY zeolite contains a large amount of extraframework aluminum ...(EFAL) species responsible for enhancing catalytic activity and improving zeolite stability. Despite numerous studies, EFAL remains, somehow, the chimaera of acid catalysis involving zeolites. Herein, we attempt to understand the influence of EFAL in the activation mechanism(s) of isobutane (chosen as a model alkane) over acidic FAU zeolites, namely HY and NaHY zeolites (exempted from EFAL), HUSY (30% of Al being EFAL) and HUSYLEFAL (EFAL partially removed by complexation with EDTA). The exchange of all Brønsted sites with deuterium enabled following the formation of primary products of isobutane cracking at 200 °C by gas online mass spectrometry. In the absence of EFAL (HY and NaHY), CH3D (m/z 17) was the sole product detected. Conversely, HUSY zeolite yielded both HD (m/z 3) and CH3D (m/z 17). Our results were interpreted as the tertiary σC–H bond in isobutane selectively underwent a protolytic reaction at low temperature solely in the presence of EFAL acid sites, while the σC–C bond could be activated by Brønsted sites in the absence of EFAL and also by EFAL acid sites. A proposal of the nature of the active EFAL site was made based on quantum chemical calculations and on the catalytic data. These results shed light on the understanding of the mechanism of small alkane activation over acidic zeolites.
The heterogeneous acid‐catalyzed activation step of alkanes leading to the reaction intermediates (carbocationic or alkoxy species) was up to now the matter of a longstanding controversy. Gas ...chromatography and online mass spectroscopy measurements show that H2 and methane are formed over H‐zeolites, whereas HD and CH3D are formed over D‐zeolites as the primary products in the reaction with isobutane. These results indicate that σ‐bond protolysis by strong acid sites is the first step for hydrocarbon activation on these catalysts at mild temperatures (473 K), in analogy to the activation path occurring in liquid superacid media.
Super acid for super people: A superacid‐like activation of alkanes occurs over zeolites. A longstanding controversy about the initial step of hydrocarbon activation on industrial catalysts (a or b, see figure), such as acidic zeolites, has been solved by experiments combining gas chromatography, mass spectroscopy and isotopic labelling of starting materials.
The increasing prevalence of obesity and, consequently, chronic inflammation and its complications has increased the search for new treatment methods. The effect of the purified tamarind seed trypsin ...inhibitor (TTIp) on metabolic alterations in Wistar rats with obesity and dyslipidemia was evaluated. Three groups of animals with obesity and dyslipidemia were formed, consuming a high glycemic index and glycemic load (HGLI) diet, for 10 days: Obese/HGLI diet; Obese/standard diet; Obese/HGLI diet + TTIp (730 μg/kg); and one eutrophic group of animals was fed a standard diet. Rats were evaluated daily for food intake and weight gain. On the 11th day, animals were anesthetized and sacrificed for blood and visceral adipose tissue collection. TTIp treated animals presented significantly lower food intake than the untreated group (p = 0.0065), TG (76.20 ± 18.73 mg/dL) and VLDL-C (15.24 ± 3.75 mg/dL). Plasma concentrations and TNF-α mRNA expression in visceral adipose tissue also decreased in obese animals treated with TTIp (p < 0.05 and p = 0.025, respectively) with a negative immunostaining. We conclude that TTIp presented anti-TNF-α activity and an improved lipid profile of Wistar rats with dyslipidemia and obesity induced by a high glycemic index and load diet regardless of
induction.
Chronic cocaine use has been shown to lead to neurotoxicity in rodents and humans, being associated with high morbidity and mortality rates. However, recreational use, which may lead to addictive ...behavior, is often neglected. This occurs, in part, due to the belief that exposure to low doses of cocaine comes with no brain damage risk. Cocaine addicts have shown glucose metabolism changes related to dopamine brain activity and reduced volume of striatal gray matter. This work aims to evaluate the morphological brain changes underlying metabolic and locomotor behavioral outcome, in response to a single low dose of cocaine in a pre-clinical study. In this context, a Balb-c mouse model has been chosen, and animals were injected with a single dose of cocaine (0.5 mg/kg). Control animals were injected with saline. A behavioral test, positron emission tomography (PET) imaging, and anatomopathological studies were conducted with this low dose of cocaine, to study functional, metabolic, and morphological brain changes, respectively. Animals exposed to this cocaine dose showed similar open field activity and brain metabolic activity as compared with controls. However, histological analysis showed alterations in the prefrontal cortex and
of mice exposed to cocaine. For the first time, it has been demonstrated that a single low dose of cocaine, which can cause no locomotor behavioral and brain metabolic changes, can induce structural damage. These brain changes must always be considered regardless of the dosage used. It is essential to alert the population even against the consumption of low doses of cocaine.
Trypsin inhibitors are studied in a variety of models for their anti-obesity and anti-inflammatory bioactive properties. Our group has previously demonstrated the satietogenic effect of tamarind seed ...trypsin inhibitors (TTI) in eutrophic mouse models and anti-inflammatory effects of other trypsin inhibitors. In this study, we evaluated TTI effect upon satiety, biochemical and inflammatory parameters in an experimental model of metabolic syndrome (MetS). Three groups of
= 5 male
rats with obesity-based MetS received for 10 days one of the following: (1) Cafeteria diet; (2) Cafeteria diet + TTI (25 mg/kg); and (3) Standard diet. TTI reduced food intake in animals with MetS. Nevertheless, weight gain was not different between studied groups. Dyslipidemia parameters were not different with the use of TTI, only the group receiving standard diet showed lower very low density lipoprotein (VLDL) and triglycerides (TG) (Kruskal-Wallis,
< 0.05). Interleukin-6 (IL-6) production did not differ between groups. Interestingly, tumor necrosis factor-alpha (TNF-α) was lower in animals receiving TTI. Our results corroborate the satietogenic effect of TTI in a MetS model. Furthermore, we showed that TTI added to a cafeteria diet may decrease inflammation regardless of weight loss. This puts TTI as a candidate for studies to test its effectiveness as an adjuvant in MetS treatment.
Background.
Individuals with Parkinson’s disease (PD) can experience motor impairments related to their hand-use that restrict participation in daily activities. Feeding is one activity impacted by ...this health condition. The use of adapted utensils can improve performance and independence in this activity.
Purpose.
To investigate if a locally designed and made eating-adaptive device helps a person with PD to improve their feeding performance.
Method.
Single-case ABC-type experimental design. Performance and satisfaction of a 60-year-old man with PD were assessed during feeding tasks in 70 sequential days in three phases. Celeration Line, Two-Standard Deviation Band, and Visual Analysis were the methods used for data analysis.
Findings.
Performance and satisfaction increased significantly after the introduction of the adaptive eating device. The addition of weight also contributed to the increase in the participant’s performance.
Implications.
Adaptive eating device with low production costs and possibility of customized adjustments improves performance of people with PD.
For environmental reasons, the production of plastic from renewable sources is gaining importance worldwide. In the case of polyethylene made from sugarcane-based ethanol, Brazil, being the world ...leader in sugarcane production, plays a fundamental role. Nevertheless, the absence of national regulations for monitoring the manufacturing process or verifying the biogenic fraction of what is already on the market raises concerns in Brazil. The main reason for the lack of such regulations is that the only approach fully capable of distinguishing identical chemical compounds of biogenic or fossil origin is the measurement of radiocarbon concentrations using an expensive and time-consuming method. Nevertheless, the measurement of stable carbon isotopes ratios has proven to be an acceptable approach to distinguish between C4 plant-derived plastics and petroleum-derived plastics. The present study compares the potential of the conventional mass spectrometry and radiocarbon accelerator mass spectrometry techniques as tools to determine the biogenic fraction of green polyethylene in Brazil. For plastics derived from either corn or sugarcane sources, δ13C values less negative than −20‰ indicate biofractions of 51% or higher. Other values would indicate the need to follow up to the radiocarbon accelerator mass spectrometry measurement, since it would not be possible to distinguish between lower biofractions and the presence of wheat or soy. The conventional mass spectrometry method can be employed for the preliminary screening of bio-based materials in manufacturing industries, representing a relatively cheap and accessible way of inspecting these products in developing countries.
•Plastic marketed as bio-based may have petroleum as a significant source.•Biofractions of plastics derived from C4 plants can be resolved via IRMS analyses.•Sugarcane based plastics were measured by both IRMS and 14C-AMS techniques.•IRMS represents a cheaper alternative to 14C-AMS analyses in biofraction studies.
Objective: This study evaluated the effect of a protein, the isolated Trypsin Inhibitor (TTI) from Tamarindus indica L. seed, as a CCK secretagogue and its action upon food intake and leptin in obese ...Wistar rats. Methods: Three groups of obese rats were fed 10 days one of the following diets: Standard diet (Labina®) + water; High Glycemic Index and Load (HGLI) diet + water or HGLI diet + TTI. Lean animals were fed the standard diet for the 10 days. Food intake, zoometric measurements, plasma CCK, plasma leptin, relative mRNA expression of intestinal CCK-related genes, and expression of the ob gene in subcutaneous adipose tissue were assessed. Results: TTI decreased food intake but did not increase plasma CCK in obese animals. On the other hand, TTI treatment decreased CCK-1R gene expression in obese animals compared with the obese group with no treatment (p = 0.027). Obese animals treated with TTI presented lower plasma leptin than the non-treated obese animals. Conclusion: We suggest that TTI by decreasing plasma leptin may improve CCK action, regardless of its increase in plasma from obese rats, since food intake was lowest.
Tumours display different cell populations with distinct metabolic phenotypes. Thus, subpopulations can adjust to different environments, particularly with regard to oxygen and nutrient availability. ...Our results indicate that progression to metastasis requires mitochondrial function. Our research, centered on cell lines that display increasing degrees of malignancy, focused on metabolic events, especially those involving mitochondria, which could reveal which stages are mechanistically associated with metastasis. Melanocytes were subjected to several cycles of adhesion impairment, producing stable cell lines exhibiting phenotypes representing a progression from non-tumorigenic to metastatic cells. Metastatic cells (4C11+) released the highest amounts of lactate, part of which was derived from glutamine catabolism. The 4C11+ cells also displayed an increased oxidative metabolism, accompanied by enhanced rates of oxygen consumption coupled to ATP synthesis. Enhanced mitochondrial function could not be explained by an increase in mitochondrial content or mitochondrial biogenesis. Furthermore, 4C11+ cells had a higher ATP content, and increased succinate oxidation (complex II activity) and fatty acid oxidation. In addition, 4C11+ cells exhibited a 2-fold increase in mitochondrial membrane potential (ΔΨmit). Consistently, functional assays showed that the migration of cells depended on glutaminase activity. Metabolomic analysis revealed that 4C11+ cells could be grouped as a subpopulation with a profile that was quite distinct from the other cells investigated in the present study. The results presented here have centred on how the multiple metabolic inputs of tumour cells may converge to compose the so-called metastatic phenotype.
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