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1.
Artigo em Inglês | MEDLINE | ID: mdl-38973337

RESUMO

Myocardial reperfusion injury (MRI) accounts for up to 50% of the final size in acute myocardial infarction and other conditions associated with ischemia-reperfusion. Currently, there is still no therapy to prevent MRI, but it is well known that oxidative stress has a key role in its mechanism. We previously reduced MRI in rats through a combined antioxidant therapy (CAT) of ascorbic acid, N-acetylcysteine, and deferoxamine. This study determines the safety and pharmacokinetics of CAT in a Phase I clinical trial. Healthy subjects (n = 18) were randomized 2:1 to CAT or placebo (NaCl 0.9% i.v.). Two different doses/infusion rates of CATs were tested in a single 90-minute intravenous infusion. Blood samples were collected at specific times for 180 minutes to measure plasma drug concentrations (ascorbic acid, N-acetylcysteine, and deferoxamine) and oxidative stress biomarkers. Adverse events were registered during infusion and followed for 30 days. Both CAT1 and CAT2 significantly increased the CAT drug concentrations compared to placebo (P < .05). Most of the pharmacokinetic parameters were similar between CAT1 and CAT2. In total, 6 adverse events were reported, all nonserious and observed in CAT1. The ferric-reducing ability of plasma (an antioxidant biomarker) increased in both CAT groups compared to placebo (P < .001). The CAT is safe in humans and a potential treatment for patients with acute myocardial infarction undergoing reperfusion therapy.

2.
Molecules ; 29(12)2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38930828

RESUMO

The development of new compounds to treat Chagas disease is imperative due to the adverse effects of current drugs and their low efficacy in the chronic phase. This study aims to investigate nitroisoxazole derivatives that produce oxidative stress while modifying the compounds' lipophilicity, affecting their ability to fight trypanosomes. The results indicate that these compounds are more effective against the epimastigote form of T. cruzi, with a 52 ± 4% trypanocidal effect for compound 9. However, they are less effective against the trypomastigote form, with a 15 ± 3% trypanocidal effect. Additionally, compound 11 interacts with a higher number of amino acid residues within the active site of the enzyme cruzipain. Furthermore, it was also found that the presence of a nitro group allows for the generation of free radicals; likewise, the large size of the compound enables increased interaction with aminoacidic residues in the active site of cruzipain, contributing to trypanocidal activity. This activity depends on the size and lipophilicity of the compounds. The study recommends exploring new compounds based on the nitroisoxazole skeleton, with larger substituents and lipophilicity to enhance their trypanocidal activity.


Assuntos
Isoxazóis , Tripanossomicidas , Trypanosoma cruzi , Trypanosoma cruzi/efeitos dos fármacos , Tripanossomicidas/farmacologia , Tripanossomicidas/química , Tripanossomicidas/síntese química , Isoxazóis/química , Isoxazóis/farmacologia , Proteínas de Protozoários/metabolismo , Proteínas de Protozoários/química , Proteínas de Protozoários/antagonistas & inibidores , Relação Estrutura-Atividade , Doença de Chagas/tratamento farmacológico , Doença de Chagas/parasitologia , Cisteína Endopeptidases/química , Cisteína Endopeptidases/metabolismo , Animais , Domínio Catalítico , Estrutura Molecular
3.
Interv Cardiol ; 19: e06, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38808282

RESUMO

Background: Ventricular arrhythmias are a leading cause of sudden death. The objective of this study was to characterise the results of patients with ventricular arrhythmias refractory to standard medical management, undergoing Video-assisted thoracoscopic cardiac sympathetic denervation (VAT-CSD) during 2012-2022 in Cali, Colombia. Methods: This was an observational retrospective study, using the Institutional General Thoracic Surgery Database for patient identification and retrospectively reviewing the clinical charts for data description and analysis. Results: Clinical records of 19 patients who underwent VAT-CSD for ventricular arrhythmia were analysed. The patients were predominantly male (73.7%) with an mean age of 62 years. Ischaemic heart disease was the main underlying condition (52.6%); all individuals had a diagnosis of heart failure, with comorbidities such as hypertension (63.1%), acute MI (57.8%) and diabetes (26.3%) also present. The procedure was performed bilaterally in 89.4% of cases and was successful with minimal perioperative complications. Postoperative follow-up showed improvement in symptoms, including a significant reduction in the number of ICD shocks and emergency department visits. Conclusion: VAT-CSD is a viable, safe and palliative therapeutic option for patients with ventricular arrhythmias who have not responded to conventional treatments, achieving a significant decrease in symptoms with low mortality and perioperative complications.

4.
Cells ; 12(21)2023 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-37947651

RESUMO

Capsaicinoids are a unique chemical species resulting from a particular biosynthesis pathway of hot chilies (Capsicum spp.) that gives rise to 22 analogous compounds, all of which are TRPV1 agonists and, therefore, responsible for the pungency of Capsicum fruits. In addition to their human consumption, numerous ethnopharmacological uses of chili have emerged throughout history. Today, more than 25 years of basic research accredit a multifaceted bioactivity mainly to capsaicin, highlighting its antitumor properties mediated by cytotoxicity and immunological adjuvancy against at least 74 varieties of cancer, while non-cancer cells tend to have greater tolerance. However, despite the progress regarding the understanding of its mechanisms of action, the benefit and safety of capsaicinoids' pharmacological use remain subjects of discussion, since CAP also promotes epithelial-mesenchymal transition, in an ambivalence that has been referred to as "the double-edge sword". Here, we update the comparative discussion of relevant reports about capsaicinoids' bioactivity in a plethora of experimental models of cancer in terms of selectivity, efficacy, and safety. Through an integration of the underlying mechanisms, as well as inherent aspects of cancer biology, we propose mechanistic models regarding the dichotomy of their effects. Finally, we discuss a selection of in vivo evidence concerning capsaicinoids' immunomodulatory properties against cancer.


Assuntos
Capsicum , Neoplasias , Humanos , Capsaicina/farmacologia , Frutas/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Biologia
5.
Sci Rep ; 13(1): 14356, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37658086

RESUMO

We reconstructed hydroclimate variability in the Yucatán Peninsula (YP) based on stalagmite oxygen and carbon isotope records from a well-studied cave system located in the northeastern YP, a region strongly influenced by Caribbean climate dynamics. The new stalagmite isotopic records span the time interval between 43 and 26.6 ka BP, extending a previously published record from the same cave system covering the interval between 26.5 and 23.2 ka BP. Stalagmite stable isotope records show dominant decadal and multidecadal variability, and weaker variability on millennial timescales. These records suggest significant precipitation declines in the broader Caribbean region during Heinrich events 4 and 3 of ice-rafted discharge into the North Atlantic, in agreement with the antiphase pattern of precipitation variability across the equator suggested by previous studies. On millennial timescales, the stalagmite isotope records do not show the distinctive saw-tooth pattern of climate variability observed in Greenland during Dansgaard-Oeschger (DO) events, but a pattern similar to North Atlantic sea surface temperature (SST) variability. We propose that shifts in the mean position of the Intertropical Convergence Zone (ITCZ), per se, are not the dominant driver of last glacial hydroclimate variability in the YP on millennial timescales but instead that North Atlantic SSTs played a dominant role. Our results support a negative climate feedback mechanism whereby large low latitude precipitation deficits resulting from AMOC slowdown would lead to elevated salinity in the Caribbean and ultimately help reactivate AMOC and Caribbean precipitation. However, because of the unique drivers of future climate in the region, predicted twenty-first century YP precipitation reductions are unlikely to be modulated by this negative feedback mechanism.

6.
Sci Rep ; 13(1): 8586, 2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37236996

RESUMO

We have conducted a monitoring survey and paleolimnological study of a W-E transect of six high altitude lakes (1870-2630 m asl) in the western and central Pyrenees (Spain) to evaluate the regional response to current global change in high altitude Mediterranean mountains. The reconstructed Total Organic Carbon (TOCflux) and lithogenic (Lflux) fluxes during the last 1200 years show the expected variability as lakes differ in altitude, geological and climate settings, limnological properties and human impact history. However, all show unique patterns after 1850 CE, particularly during the Great Acceleration (after 1950 CE). Recent Lflux increase could be related to higher erodibility by rainfall and run-off during the longer snow-free season in the Pyrenees. In all sites, higher TOCflux and geochemical (lower δ13COM, lower C/N) and biological (diatom assemblages) signatures since 1950 CE suggest an increase in algal productivity, likely favored by warmer temperatures and higher nutrient deposition. These recent, unprecedented Lflux and TOCflux increases, in spite of their diverse history and limnological properties of the lakes, demonstrate the regional impact of the Great Acceleration not only in the ecological dynamics of alpine lakes but also in the hydrological cycle in high altitude mountain watersheds.

7.
Nat Commun ; 14(1): 2700, 2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37164947

RESUMO

The end of the Middle Pleistocene Transition (MPT, ~ 800-670 thousand years before present, ka) was characterised by the emergence of large glacial ice-sheets associated with anomalously warm North Atlantic sea surface temperatures enhancing moisture production. Still, the direction and intensity of moisture transport across Eurasia towards potential ice-sheets is poorly constrained. To reconstruct late MPT moisture production and dispersal, we combine records of upper ocean temperature and pollen-based Mediterranean forest cover, a tracer of westerlies and precipitation, from a subtropical drill-core collected off South-West Iberia, with records of East Asia summer monsoon (EASM) strength and West Pacific surface temperatures, and model simulations. Here we show that south-western European winter precipitation and EASM strength reached high levels during the Marine Isotope Stage 18 glacial. This anomalous situation was caused by nearly-continuous moisture supply from both oceans and its transport to higher latitudes through the westerlies, likely fuelling the accelerated expansion of northern hemisphere ice-sheets during the late MPT.

8.
Horiz. sanitario (en linea) ; 21(2): 222-228, May.-Aug. 2022. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1448408

RESUMO

Resumen: Objetivo: Identificar la presencia de violencia de género en mujeres confinadas, debido a la pandemia por Covid-19 en la región Costa de Oaxaca. Materiales y métodos: Investigación cuantitativa, descriptiva, correlacional y de corte transversal en 50 mujeres mayores de 18 años, que permanecieron al menos 1 mes confinadas debido a la pandemia por Covid-19, a quienes aplicaron un cuestionario que empleó el Índice de Severidad de Violencia de Pareja, respetando las recomendaciones éticas pertinentes de la Ley General de Salud en Materia de Investigación para la Salud. Los datos fueron procesados en el programa estadístico SPSS versión 21 y se empleó estadística descriptiva y el coeficiente de correlación de Pearson. Resultados: Se encontró una prevalencia de violencia psicológica de 90%, 72% de las mujeres notificaron violencia física y 64% fueron víctimas de violencia sexual. Se observa correlación positiva entre la edad con la violencia física (r= 0.405, p=0.004), violencia psicológica (r= 0.416, p= 0.003) y la violencia sexual (r= 0.527, p=0.000); se observa correlación negativa en las variables escolaridad y violencia física (r= -0.538, p= 0.000), violencia psicológica (r= -0.488, p= 0.000), violencia sexual (r=-0.411, p= 0.003). Conclusiones: La violencia de género es un tema que ha tomado gran relevancia en los últimos años, y que en la actualidad sigue siendo preocupante. A pesar de que se ha difundido información, sigue existiendo violencia dentro de los hogares mexicanos, en la Costa de Oaxaca durante el confinamiento por Covid-19 la violencia de género ha sido altamente prevalente, por lo que se requiere implementar medidas tendentes a prevenir y tratar la violencia de género.


Abstract: Objective: To identify the presence of gender-based violence in women confined due to the Covid-19 pandemic in the Oaxaca Coast Region Materials and methods: Quantitative, descriptive, correlational and cross-sectional research in 50 women over 18 years of age who remained at least 1 month in confinement due to the Covid-19 pandemic, who applied a questionnaire using the Intimate Partner Violence Severity Index, respecting the pertinent ethical recommendations of the General Health Law on Health Research. The data were processed in the SPSS version 21 statistical program and descriptive statistics and Pearson´s correlation coefficient were used. Results: A prevalence of psychological violence was found to be 90%. 72% of the women reported physical violence and 64% were victims of sexual violence. A positive correlation was observed between age and physical violence (r= 0.405, p= 0.004), psychological violence (r= 0.416, p= 0.003) and sexual violence (r= 0.527, p=0.000); a negative correlation was observed in the variables schooling and physical violence (r= -0.538, p= 0.000), psychological violence (r= -0.488, p= 0.000), sexual violence (r= -0.411, p= 0.003). Conclusions: Gender-based violence is an issue that has taken great relevance in recent years, and that currently continues to be of concern. Despite the fact that information has been disseminated, violence continues to exist within mexican homes. In the Oaxaca Coast during the confinement by Covid-19, gender-based violence has been highly prevalent, which is why it is necessary to implement measures to prevent and treat gender-based violence.

9.
Materials (Basel) ; 15(9)2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35591451

RESUMO

In this work, we studied the phases in a Mg-Ti-O system using a 1:1 formulation of MgO:TiO2, mixing synthetic brucite of Mexican origin with TiO2 microparticles of high purity, with a heat treatment at 1100 °C for 1 h. Due to its valence electrons, TiO2 can contribute to the sintering process to improve density in MgO products. The raw materials and formulation by XPS and X-RD techniques were characterized. The results demonstrate the presence of different oxidation states in titania and the formation of different oxides in the Mg-Ti-O system when mixed and calcined at 1100 °C; additionally, we estimated the formation of vacancies in the crystal lattice during the transformation from hexagonal brucite to magnesia with a cubic structure centered on the faces. Its thermal behavior is indicated by the MgO-TiO2 phase diagram.

10.
Materials (Basel) ; 15(7)2022 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-35407755

RESUMO

The deterioration of the refractory lining represents a significant problem for the smooth operation in the ferroalloys industry, particularly in the production of silicomanganese, due to the periodic requirements of substitution of the damaged refractory. Within this context, magnesia refractories are commonly employed in the critical zones of the furnaces used in silicomanganese production since the slag involved in the process has a basic character. The behavior of MgO-ZrO2 ceramic composites with different ZrO2 nanoparticles (0, 1, 3, and 5 wt.%) contents in the presence of silicomanganese slags is proposed in this manuscript. XPS, XRD and SEM-EDX were used to evaluate the properties of the ceramic composite against the silicomanganese slag. The static corrosion test was used to evaluate the corrosion of the refractory. Results suggest that corrosion is controlled by the change in slag viscosity due to the reaction between CaZrO3 and the melted slag. Besides, ZrO2 nanoparticles located at both triple points and grain boundaries act as a barrier for the slag advance within the refractory. The utilization of MgO refractories with ZrO2 nanoparticles can extend the life of furnaces used to produce silicomanganese.

11.
Molecules ; 27(3)2022 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-35163871

RESUMO

Plant biochemistry studies have increased in recent years due to their potential to improve human health. Argylia radiata is an extremophile plant with an interesting polyphenolic profile. However, its biomass is scarce and occasionally available. Argylia in vitro biomass was obtained from tissue culture and compared with in vivo roots regarding its polyphenolic and flavonoid content. Different solvents were used to prepare extracts from the in vitro tissue of callus and aerial plant organs and in vivo roots. UPLC-MS/MS was used to assess the chemical composition of each extract. ORAC-FL and scavenging of free radicals (DPPH and OH) methods were used to determine the antioxidant capacity of extracts. Furthermore, the biological activity of the extracts was established using the cellular antioxidant activity method. The vitroplants were a good source of polyphenols (25-68 mg GAE/100 g tissue FW), and methanol was the most efficient solvent. Eight polyphenolic compounds were identified, and their antioxidant properties were investigated by different chemical methods with EPR demonstrating its specific scavenging activity against free radicals. All extracts showed cellular dose-dependent antioxidant activity. The methanolic extract of vitroplants showed the highest cellular antioxidant activity (44.6% and 51%) at 1 and 10 µg/mL of extract, respectively. Vitroplants of A. radiata are proposed as a biotechnological product as a source of antioxidant compounds with multiple applications.


Assuntos
Antioxidantes/farmacologia , Begoniaceae/química , Sequestradores de Radicais Livres/farmacologia , Raízes de Plantas/química , Polifenóis/análise , Polifenóis/farmacologia , Solventes/química
12.
Environ Res ; 204(Pt A): 111895, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34437852

RESUMO

This paper analyses the probabilistic future behaviour of heat-waves (HWs) in the city of Madrid in the twenty-first century, using maximum daily temperatures from twenty-one climate circulation models under two representative concentration pathways (RCP 8.5 & RCP 4.5). HWs are modelled considering three factors: number per annum, duration and intensity, characterised by three stochastic processes: Poisson, Gamma and truncated Gaussian, respectively. Potential correlations between these processes are also considered. The probabilistic temperature behaviour is combined with an epidemiological model with stochastic mortality risk following a generalized extreme value distribution (gev). The objective of this study is to obtain probability distributions of mortality and risk measures such as the mean value of the 5% of worst cases in the 21st century, in particular from 2025 to 2100. Estimates from stochastic models for characterising HWs and epidemiological impacts on human health can vary from one climate model to another, so relying on a single climate model can be problematic. For this reason, the calculations are carried out for 21 models and the average of the results is obtained. A sensitivity adaptation analysis is also performed. Under RCP 8.5 for 2100 for Madrid city a mean excess of 3.6 °C over the 38 °C temperature threshold is expected as the average of all models, with an expected attributable mortality of 1614 people, but these figures may be substantially exceeded in some cases if the highest-risk cases occur.


Assuntos
Modelos Climáticos , Temperatura Alta , Adaptação Fisiológica , Mudança Climática , Modelos Epidemiológicos , Humanos , Mortalidade
13.
Molecules ; 26(24)2021 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-34946751

RESUMO

Angiogenesis, the formation of new blood vessels, underlies tissue development and repair. Some medicinal plant-derived compounds can modulate the angiogenic response. Heliopsis longipes, a Mexican medicinal plant, is widely used because of its effects on pain and inflammation. The main bioactive phytochemicals from H. longipes roots are alkamides, where affinin is the most abundant. Scientific studies show various medical effects of organic extracts of H. longipes roots and affinin that share some molecular pathways with the angiogenesis process, with the vasodilation mechanism of action being the most recent. This study investigates whether pure affinin and the ethanolic extract from Heliopsis longipes roots (HLEE) promote angiogenesis. Using the aortic ring rat assay (ex vivo method) and the direct in vivo angiogenesis assay, where angioreactors were implanted in CD1 female mice, showed that affinin and the HLEE increased vascular growth in a dose-dependent manner in both bioassays. This is the first study showing the proangiogenic effect of H. longipes. Further studies should focus on the mechanism of action and its possible therapeutic use in diseases characterized by insufficient angiogenesis.


Assuntos
Asteraceae/química , Etanol/química , Neovascularização Fisiológica/efeitos dos fármacos , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Alcamidas Poli-Insaturadas/farmacologia , Animais , Aorta Torácica/efeitos dos fármacos , Estrutura Molecular , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Raízes de Plantas/química , Plantas Medicinais , Alcamidas Poli-Insaturadas/química , Alcamidas Poli-Insaturadas/isolamento & purificação , Ratos
14.
Int J Nanomedicine ; 16: 5879-5894, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34471354

RESUMO

PURPOSE: The importance of studying polyphenolic compounds as natural antioxidants has encouraged the search for new methods of analysis that are quick and simple. The synthesis of silver nanoparticles (AgNPs) using plant extracts has been presented as an alternative to determine the total polyphenolic content and its antioxidant activity. METHODS: In this study, aqueous leaf extract of Solanum mammosum, a species of plant endemic to South America, was used to produce AgNPs. The technique of oxygen radical absorption capacity using fluorescein (ORAC-FL) was used to measure antioxidant activity. The oxidation of the 2´,7´-dichlorodihydrofluorescein diacetate (DCFH2-DA) as fluorescent probe was used to measure cellular antioxidant activity (CAA). Electrochemical behavior was also examined using differential pulse voltammetry (DPV) and cyclic voltammetry (CV). Total polyphenolic content (TPH) was analyzed using the Folin-Ciocalteu method, and the major polyphenolic compound was analyzed by high performance liquid chromatography with diode array detector (HPLC/DAD). Finally, a microbial analysis was conducted using Escherichia coli and Bacillus sp. RESULTS: The average size of nanoparticles was 5.2 ± 2.3 nm measured by high-resolution transmission electron microscopy (HR-TEM). The antioxidant activity measured by ORAC-FL in the extract and nanoparticles were 3944 ± 112 and 637.5 ± 14.8 µM ET/g of sample, respectively. Cellular antioxidant activity was 14.7 ± 0.2 for the aqueous extract and 12.5 ± 0.2 for the nanoparticles. The electrochemical index (EI) was 402 µA/V for the extract and 324 µA/V for the nanoparticles. Total polyphenolic content was 826.6 ± 20.9 and 139.7 ± 20.9 mg EGA/100 g of sample. Gallic acid was the main polyphenolic compound present in the leaf extract. Microbiological analysis revealed that although leaf extract was not toxic for Escherichia coli and Bacillus sp., minor toxic activity for AgNPs was detected for both strains. CONCLUSION: It is concluded that the aqueous extract of the leaves of S. mammosum contains nontoxic antioxidant compounds capable of producing AgNPs. The methods using AgNPs can be used as a fast analytical tool to monitor the presence of water-soluble polyphenolic compounds from plant origin. Analysis and detection of new antioxidants from plant extracts may be potentially applicable in biomedicine.


Assuntos
Nanopartículas Metálicas , Solanum , Antioxidantes , Fluoresceína , Capacidade de Absorbância de Radicais de Oxigênio , Extratos Vegetais , Espécies Reativas de Oxigênio , Prata , Água
15.
Molecules ; 26(10)2021 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-34068159

RESUMO

Walnut green husk (WGH) is a waste generated by the walnut (Juglans regia L.) harvest industry. It represents a natural source of polyphenols, compounds with antioxidant and antimicrobial activities, but their activity could be dependent on the ripeness stage of the raw material. In this study, the effect of the different ripeness stages-open (OH) and closed (CH) husks-on the antioxidant and antimicrobial properties of WGH extracts were analyzed, emphasizing the influence of the extracts in inhibiting Escherichia coli growth. The ripeness stage of WGH significantly affected the antioxidant activity of the extracts. This was attributed to the different polyphenol profiles related to the mechanical stress when the husk opened compared to the closed sample. The antimicrobial activity showed inhibition of E. coli growth. OH-extracts at 96 µg/mL caused the lowest specific growth rate (µmax = 0.003 h-1) and the greatest inhibition percentage (I = 93%) compared to CH-extract (µmax = 0.01 h-1; I = 69%). The obtained results showed the potential of the walnut green husk, principally open husk, as an economical source of antioxidant and antimicrobial agents with potential use in the food industry.


Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Indústrias , Juglans/química , Extratos Vegetais/farmacologia , Bactérias/efeitos dos fármacos , Cinética , Testes de Sensibilidade Microbiana , Polifenóis/farmacologia
16.
Sci Total Environ ; 751: 141851, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32898748

RESUMO

Worldwide increases in droughts- and heat-waves-associated tree mortality events are destabilizing the future of many forests and the ecosystem services they provide. Along with climate, understanding the impact of the legacies of past forest management is key to better explain current responses of different tree species to climate change. We studied tree mortality events that peaked in 2012 affecting one native (silver fir; growing within its natural distribution range) and two introduced (black pine and Scots; growing outside their natural distribution range) conifer species from the Romanian Carpathians. The three conifers were compared in terms of mortality events, growth trends, growth resilience to severe drought events, climate-growth relationships, and regeneration patterns. The mortality rates of the three species were found to be associated with severe drought events. Nevertheless, the native silver fir seems to undergo a self-thinning process, while the future of the remaining living black pine and Scots pine trees is uncertain as they register significant negative growth trends. Overall, the native silver fir showed a higher resilience to severe drought events than the two introduced pine species. Furthermore, and unlike the native silver fir, black pine and Scots pine species do not successfully regenerate. A high diversity of native broadleaf species sprouts and develops instead under them suggesting that we might be witnessing a process of ecological succession, with broadleaves recovering their habitats. As native species seem to perform better in terms of resilience and regeneration than introduced species, the overall effect of the black pine and Scots pine mortality might be compensated. Legacies of past forest management should be taken into account in order to better understand current responses of different tree species to ongoing climate change.


Assuntos
Secas , Traqueófitas , Ecossistema , Florestas , Romênia , Árvores
17.
Sci Rep ; 10(1): 21277, 2020 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-33277562

RESUMO

The wavelet local multiple correlation (WLMC) is introduced for the first time in the study of climate dynamics inferred from multivariate climate time series. To exemplify the use of WLMC with real climate data, we analyse Last Millennium (LM) relationships among several large-scale reconstructed climate variables characterizing North Atlantic: i.e. sea surface temperatures (SST) from the tropical cyclone main developmental region (MDR), the El Niño-Southern Oscillation (ENSO), the North Atlantic Multidecadal Oscillation (AMO), and tropical cyclone counts (TC). We examine the former three large-scale variables because they are known to influence North Atlantic tropical cyclone activity and because their underlying drivers are still under investigation. WLMC results obtained for these multivariate climate time series suggest that: (1) MDRSST and AMO show the highest correlation with each other and with respect to the TC record over the last millennium, and: (2) MDRSST is the dominant climate variable that explains TC temporal variability. WLMC results confirm that this method is able to capture the most fundamental information contained in multivariate climate time series and is suitable to investigate correlation among climate time series in a multivariate context.

18.
Materials (Basel) ; 13(3)2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31973124

RESUMO

The search for sensitive and rapid analytical techniques for the determination of natural antioxidants is an area in constant growth due, among other aspects, to the complexity of plant matrices. In this study, silver nanoparticles prepared with the aqueous extract of Mimosa albida leaves were used to assess their polyphenolic content and antioxidant capacity. Silver nanoparticles were characterized by different techniques. As a result, nanoparticles of 6.5 ± 3.1 nm were obtained. The total phenolic content in the extract was 1320.4 ± 17.6 mg of gallic acid equivalents GAE. 100 g-1 and in the nanoparticles 257.3 ± 5.1 mg GAE. 100 g-1. From the phenolic profile analyzed by ultra high-performance liquid chromatography (UPLC) with a diode-array detector (DAD), the presence of apigenin and luteolin in the plant extract is postulated. The antioxidant capacity measured by oxygen radical absorbance capacity ORAC-fluorescein assay was 86917 ± 6287 and 7563 ± 967 µmol ET g-1 in the extract and nanoparticles respectively. Electrochemical analysis by cyclic voltammetry (CV) confirmed the effective reduction capacity of the Mimosa albida leaves extract to reduce Ag ions to AgNPs and differential pulse voltammetry (DPV) suggested the presence of two main reducing agents in the extract. From this study, it was concluded that the aqueous extract of Mimosa albida contains reducing agents capable of synthesizing silver nanoparticles, which can be used in the phytochemical industry.

19.
Patient Educ Couns ; 103(1): 127-135, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31521424

RESUMO

OBJECTIVE: Growing use of clinical exome sequencing (CES) has led to an increased burden of genomic education. Self-guided educational tools can minimize the educational burden for genetic counselors (GCs). The effectiveness of these tools must be evaluated. METHODS: Parents of patients offered CES were randomized to watch educational videos before their visit or to receive routine care. Parents and GCs were surveyed about their experiences following the sessions. The responses of the video (n = 102) and no-video (n = 105) groups were compared. RESULTS: GCs reported no significant differences between parents in the video and no-video groups on genetics knowledge or CES knowledge. In contrast, parents' scores on genetics knowledge questions were lower in the video than no-video group (p = 0.007). Most parents reported the videos were informative, and the groups did not differ in satisfaction with GCs or decisions to have CES. CONCLUSION: GCs and parents perceived the videos to be beneficial. However, lower scores on genetics knowledge questions highlight the need for careful development of educational tools. PRACTICE IMPLICATIONS: Educational tools should be developed and assessed for effectiveness with the input of all stakeholders before widespread implementation. Better measures of the effectiveness of these educational tools are needed.


Assuntos
Conselheiros , Aconselhamento Genético , Exoma , Humanos , Pais , Educação de Pacientes como Assunto
20.
Obes Surg ; 30(1): 102-110, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31515727

RESUMO

INTRODUCTION: Bariatric surgery has been shown to be effective in reducing weight and has benefits, such as lowering blood pressure. An increase in urinary sodium excretion has been suggested as a possible mechanism. This study explored changes in sodium excretion and their correlation with blood pressure after Roux-en-Y gastric bypass. MATERIALS AND METHODS: This study was conducted on 28 obese participants with body mass index (BMI) of 44.54 ± 7.81 kg/m2 who underwent gastric bypass. Before surgery and at the third and sixth months after gastric bypass, blood pressure, urinary sodium concentration, 24-hour (24-h) urinary sodium excretion, and fractional excretion of sodium were evaluated. In addition, serum sodium and potassium levels were determined. Nonparametric tests were used to analyze the data. RESULTS: Blood pressure decreased after surgery and remained at low levels over the 3- and 6-month periods. The urinary sodium concentration increased at 3 months after surgery; however, the 24-h urinary sodium excretion and urine volume decreased. Interestingly, although some associations between variables were observed, significant correlations between the 24-h urinary sodium excretion and the systolic, diastolic, and mean blood pressures were found. In addition, the urine volume was higher in the sixth month than in the third month following surgery. CONCLUSIONS: In the months immediately following surgery, a low-salt and low-volume diet favors decreases in urine volume and 24-h urinary sodium excretion. In addition, in the sixth month after surgery, an association between blood pressure and 24-h urinary sodium excretion was observed.


Assuntos
Pressão Sanguínea/fisiologia , Derivação Gástrica , Obesidade Mórbida/cirurgia , Eliminação Renal/fisiologia , Sódio/metabolismo , Adulto , Índice de Massa Corporal , Feminino , Seguimentos , Derivação Gástrica/métodos , Taxa de Filtração Glomerular , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/metabolismo , Obesidade Mórbida/fisiopatologia , Obesidade Mórbida/urina , Período Pós-Operatório , Potássio/sangue , Sódio/sangue , Sódio/urina , Fatores de Tempo , Redução de Peso/fisiologia
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