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1.
Sci Total Environ ; 912: 168664, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-37996016

RESUMO

In this study we found that endocrine disrupting chemicals (EDCs) were omnipresent in a tropical seabird community comprising diverse ecological guilds and distinct foraging and trophic preferences. Because EDCs tend to bioaccumulate within the food web and microplastics can absorb and release harmful chemical compounds, our findings draw attention to the potential threats to wildlife. Thus, the goal of this study was to investigate the role of plastic ingestion, trophic and foraging patterns (δ15N and δ13C) of five tropical seabird species breeding in sympatry, on the exposure to EDCs, namely Polybrominated diphenyl ethers (PBDEs), methoxylated polybrominated diphenyl ethers (MeO-PBDEs) and personal care products (PCPs, e.g., musk fragrances and UV-filters). Results indicated that microplastics occurrence and EDCs detection frequency varied among species. Microplastics occurrence was higher in species with dual and coastal foraging strategies. Preen oil had higher levels of MeO-PBDEs and PCPs, while serum had higher levels of PBDEs. In brown boobies, the correlation between microplastics and ∑PBDEs levels was significant, suggesting that microplastics ingestion is a key PBDEs route. Trophic position (δ15N) plays a key role in PBDEs accumulation, particularly in Bulwer's petrel, which occupies a high trophic position and had more specialized feeding ecology than the other species. MeO-PBDEs were linked to foraging habitat (δ13C), although the link to foraging locations deserves further investigation. Overall, our findings not only fill key gaps in our understanding of seabirds' exposure to microplastics and EDCs, but also provide an essential baseline for future research and monitoring efforts. These findings have broader implications for the marine wildlife conservation and pollution management in sensitive environments, such as the tropical regions off West Africa.


Assuntos
Disruptores Endócrinos , Monitoramento Ambiental , Animais , Éteres Difenil Halogenados/análise , Microplásticos , Plásticos , Animais Selvagens , Aves , Ingestão de Alimentos
2.
Sci Rep ; 13(1): 21079, 2023 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-38030663

RESUMO

Normal-to-cancer (NTC) transition is known to be closely associated to cell´s biomechanical properties which are dependent on the dynamics of the intracellular medium. This study probes different human cancer cells (breast, prostate and lung), concomitantly to their healthy counterparts, aiming at characterising the dynamical profile of water in distinct cellular locations, for each type of cell, and how it changes between normal and cancer states. An increased plasticity of the cytomatrix is observed upon normal-to-malignant transformation, the lung carcinoma cells displaying the highest flexibility followed by prostate and breast cancers. Also, lung cells show a distinct behaviour relative to breast and prostate, with a higher influence from hydration water motions and localised fast rotations upon NTC transformation. Quasielastic neutron scattering techniques allowed to accurately distinguish the different dynamical processes taking place within these highly heterogeneous cellular systems. The results thus obtained suggest that intracellular water dynamics may be regarded as a specific reporter of the cellular conditions-either healthy or malignant.


Assuntos
Neoplasias , Água , Humanos , Difração de Nêutrons , Nêutrons
3.
Sci Total Environ ; 898: 165437, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-37437636

RESUMO

Oceans have been considered as an unlimited supply of goods and services, but resource extraction and waste disposal became ubiquitous and have been damaging the health of marine ecosystems. Finding suitable sentinel species of the human impacts on the oceans is thus imperative, since they may work as early warnings of disruptive situations. In this study, we investigated how taxonomy and foraging distribution influenced the occurrence of anthropogenic debris among five seabird species inhabiting the tropical Atlantic region. Occurrence of anthropogenic debris was assessed using faeces of breeding individuals as a proxy of ingestion. A total of 268 particles were extracted from all samples. The categories "fragments" and "fibres", as well as the colour "blue", were the most prevalent characteristics across species. There was a high diversity of polymers from cellulosic particles to synthetic plastics (Anthropogenic Cellulosic 26.9 %; Polyester 7.7 %; Varnish 5.8 %; Polypropylene 1.9 %). Species with a more coastal foraging strategy exhibited higher occurrence and number of anthropogenic debris when compared to species foraging comparably more in pelagic areas. This suggests that anthropogenic debris are more prevalent in coastal foraging areas, where human activities occur in higher number and frequency (e.g., fisheries) and sources of freshwater input from inland are at close distance. These results provide more evidence to the growing perception on the ubiquity and diversity of anthropogenic debris in the marine environment, and further support the usefulness of using seabirds as bio-indicators of anthropogenic pollution in both neritic and oceanic regions.


Assuntos
Ecossistema , Resíduos , Humanos , Animais , Resíduos/análise , Monitoramento Ambiental/métodos , Plásticos , Aves , Ingestão de Alimentos
4.
Forensic Sci Int ; 347: 111690, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37086578

RESUMO

Acetic acid treatment for an accurate differentiation between ancient and recent human bones was assessed using Raman and FTIR-ATR spectroscopies. Each set of skeletal samples was analysed by these techniques, prior and after chemical washing, in order to determine the variations in bone´s chemical composition and crystallinity. Bone samples were collected from several independent sources: recent bones burned under controlled experimental conditions or cremated, and archaeological (XVII century and Iron Age). The effect of acetic acid, expected to impact mostly on carbonates, was clearly evidenced in the spectra of all samples, particularly in FTIR-ATR, mainly through the bands typical of A- and B-carbonates. Furthermore, as seen for crematoria and archaeological samples, acetic acid was found to remove contaminants such as calcium hydroxide. Overall, acetic acid treatment can be an effective method for removing carbonates (exogenous but possibly also endogenous) and external contaminants from bone. However, these effects are dependent on the skeletal conditions (e.g. post-mortem interval and burning settings). In addition, this chemical washing was shown to be insufficient for an unequivocal discrimination between recent and archaeological skeletal remains. Based on the measured IR indexes, only cremated bones could be clearly distinguished.


Assuntos
Ácido Acético , Restos Mortais , Humanos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Carbonatos/análise , Osso e Ossos/química
5.
Sci Total Environ ; 869: 161703, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-36708826

RESUMO

Marine plastic contamination is currently considered ubiquitous in aquatic environments. These particles present a resistant and hydrophobic substrate known to promote microbial colonisation and biofilm formation in aquatic ecosystems, the so-called "Plastisphere", raising concerns about its potential ecological risks. The novelty of this topic translates into a relatively low number of studies, including for transitional coastal ecosystems, such as sandy beaches or estuarine habitats. Therefore, a sampling campaign was conducted in two transitional coastal ecosystems - the Mondego estuary (Portugal) - and adjacent sandy beaches (winter 2020). After visual sorting and filtering of suspected particles under sterile conditions DNA extraction and 16S rRNA amplicon high throughput sequencing was used to profile the bacterial communities on the surface of plastic particles and from those found on the water and sediments from the sampled transitional coastal ecosystems. All particles were characterised according to type, colour and size, and the chemical nature of the particles was determined by FTIR-ATR or µ-FTIR spectroscopy after DNA extraction. All samples contained plastics in several sizes (micro and mesoplastics), shapes (higher abundances of fragments on beaches and fibres in the estuarine waters), colours and polymers. Although no significant differences were detected in the α-diversity indexes of the bacterial communities between plastics and their surrounding environments, data showed the occurrence of unique key bacterial groups on plastics from both environments, such as pathogens (e.g., Lactococcus, Staphylococcus and Streptococcus) and groups commonly associated with wastewater treatment plants (e.g., members of the phylum Firmicutes). This highlights the concerns for plastics to act as vectors of transmission and spread of these bacterial groups in transitional coastal ecosystems. Furthermore, it raises the possibility that (micro)plastics entering the estuary from the sea play a substantial contribution to overall dynamics of (micro)plastics and their microbial assemblages in the estuarine system.


Assuntos
Ecossistema , Poluentes Químicos da Água , RNA Ribossômico 16S/genética , Poluentes Químicos da Água/análise , Plásticos , Bactérias , DNA
6.
Phys Chem Chem Phys ; 24(25): 15406-15415, 2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35704895

RESUMO

Normal-to-malignant transformation is a poorly understood process associated with cellular biomechanical properties. These are strongly dependent on the dynamical behaviour of water, known to play a fundamental role in normal cellular activity and in the maintenance of the three-dimensional architecture of the tissue and the functional state of biopolymers. In this study, quasi-elastic neutron scattering was used to probe the dynamical behaviour of water in human cancer specimens and their respective surrounding normal tissue from breast and tongue, as an innovative approach for identifying particular features of malignancy. This methodology has been successfully used by the authors in human cells and was the first study of human tissues by neutron scattering techniques. A larger flexibility was observed for breast versus tongue tissues. Additionally, different dynamics were found for malignant and non-malignant specimens, depending on the tissue: higher plasticity for breast invasive cancer versus the normal, and an opposite effect for tongue. The data were interpreted in the light of two different water populations within the samples: one displaying bulk-like dynamics (extracellular and intracellular/cytoplasmic) and another with constrained flexibility (extracellular/interstitial and intracellular/hydration layers).


Assuntos
Neoplasias , Água , Humanos , Difração de Nêutrons/métodos , Nêutrons
7.
Sci Rep ; 12(1): 3707, 2022 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-35260648

RESUMO

The "Hypogeum of the Garlands" is a sepulchral site, recently found in Grottaferrata (Lazio, Italy), dating back to the first-second century AD. Two sarcophagi were discovered inside, hosting the human remains of Aebutia Quarta, a rich Roman woman, and her son Carvilius Gemellus. While the body of Carvilius is exceptionally well-preserved, following its embalming and perfect sealing of the sarcophagus, in the case of Aebutia only the bones were preserved because of the sarcophagus's seal breaking down, although she was covered with perfectly preserved flower garlands. Embalming of the body was a rare ritual in the Imperial Roman times when corpses were more often cremated. The remains of Aebutia showed possible traces of heating. Burned bones from a third individual were discovered on the chamber's floor and preliminary anthropological survey showed that this individual was a male of 40-50 years old. Here, a combination of spectroscopic techniques, including non-destructive inelastic neutron scattering and Raman spectroscopy, and minimally destructive Fourier transform infrared spectroscopy, were applied to the analysis of these bone samples to give information about ancient Roman funerary practices. The temperature and burning conditions were thus determined, showing that Aebutia Quarta was exposed to mild temperatures (200 °C) only in the upper part of the body, while the third individual was likely cremated as its bones were exposed to temperatures up to 900 °C in quasi-anaerobic conditions.


Assuntos
Osso e Ossos , Análise Espectral Raman , Adulto , Feminino , História Antiga , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Espectroscopia de Infravermelho com Transformada de Fourier
8.
Int J Legal Med ; 136(1): 309-317, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34613463

RESUMO

In forensic anthropology, there is an inherent difficulty in estimating the post-mortem interval (PMI). This study aimed to assess whether there is a correlation between changes in the bone mineral component and the PMI estimation. Samples of femur and humerus from 80 identified individuals with known post-mortem interval were analyzed. Infrared spectroscopy in attenuated total reflectance mode (FTIR-ATR) was applied for this analysis, several indices having been obtained from the infrared bands most representative of the bone's relative contents in carbonate and phosphate. Specific relationships between sex/age and PMI were attained: for larger PMIs, there was an increase in the amount of B-type carbonate (BPI), A-type carbonates (API), and in the carbonate/phosphate (C/P) ratio, and a decrease of the crystallinity index (CI) and in the carbonate ratio (C/C). Two particular infrared indices (CI and C/C) were identified as the most suitable for post-mortem interval estimation, especially in females, controlling the effects of sex and age (in the statistical analysis).


Assuntos
Antropologia Forense , Úmero , Autopsia/métodos , Feminino , Fêmur/química , Antropologia Forense/métodos , Humanos , Mudanças Depois da Morte , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
9.
R Soc Open Sci ; 8(10): 210774, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34729208

RESUMO

This study aims to analyse human bones exposed to low/medium temperatures (200-650°C) under experimentally controlled conditions, both oxidizing and reducing, using complementary optical and neutron vibrational spectroscopy techniques. Clear differences were observed between the aerobically and anaerobically heated bones. The organic constituents disappeared at lower temperatures for the former (ca 300°C), while they lingered for higher temperatures in anaerobic environments (ca 450-550°C). Unsaturated non-graphitizing carbon species (chars) were detected mainly for anaerobically heated samples, and cyanamide formation occurred only at 650°C in reducing settings. Overall, the main changes were observed from 300 to 400°C in anaerobic conditions and from 450 to 500°C in aerobic environments. The present results enabled the identification of specific spectroscopic biomarkers of the effect of moderate temperatures (less than or equal to 650°C) on human bone, thus contributing to a better characterization of forensic and archaeological skeletal remains subject to heating under distinct environmental settings. In particular, these data may provide information regarding cannibalism or ancient bone boiling and defleshing rituals.

10.
Sci Rep ; 11(1): 1361, 2021 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-33446708

RESUMO

Complementary optical and neutron-based vibrational spectroscopy techniques (Infrared, Raman and inelastic neutron scattering) were applied to the study of human bones (femur and humerus) burned simultaneously under either aerobic or anaerobic conditions, in a wide range of temperatures (400 to 1000 °C). This is the first INS study of human skeletal remains heated in an oxygen-deprived atmosphere. Clear differences were observed between both types of samples, namely the absence of hydroxyapatite's OH vibrational bands in bone burned anaerobically (in unsealed containers), coupled to the presence of cyanamide (NCNH2) and portlandite (Ca(OH)2) in these reductive conditions. These results are expected to allow a better understanding of the heat effect on bone´s constituents in distinct environmental settings, thus contributing for an accurate characterisation of both forensic and archaeological human skeletal remains found in distinct scenarios regarding oxygen availability.


Assuntos
Restos Mortais/química , Fêmur/química , Temperatura Alta , Úmero/química , Humanos , Análise Espectral Raman
11.
J Food Sci Technol ; 57(12): 4443-4458, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33087958

RESUMO

The Sarcocornia genus is an extreme salt-tolerant plant that can be cultivated in saline habitats almost worldwide. To preserve Sarcocornia perennis, convective drying experiments were conducted and their effects on the physico-chemical properties and phenolic content of the plant were studied using conventional and vibrational spectroscopy techniques. The drying process of Sarcocornia perennis at temperatures of 40 °C, 50 °C, 60 °C and 70 °C revealed three periods of convective drying process with drying times ranging between 4.5 and 24.9 h, respectively to higher and lower temperatures. The heating-up period can be neglected as compared with the drying process, and the duration of constant rate period, as a percentage of the total drying time, ranged between 34 and 20% respectively at 40 °C and 70 °C. The Modified Page model was proposed to describe the drying process at the different temperatures. From a nutritional point of view, this halophyte plant may be considered as a good source of fibres, phenolic compounds and natural minerals, such as sodium, potassium, calcium and magnesium. The convective drying, in the temperature range currently used, was found to preserve the colour, nutritional characteristics and phytochemical value of Sarcocornia perennis. These results were confirmed by FTIR-ATR and highlight the potential use of the dried plant in novel food products.

12.
Anal Methods ; 12(39): 4806-4812, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-32955042

RESUMO

Palladium-(Pd)-based drugs are emerging as alternatives to platinum (Pt) anticancer chemotherapeutics, which increases the need for efficient and suitable procedures of Pd analysis in reduced amounts of pre-clinical animal samples. Herein, an ICP-MS (inductively coupled plasma-mass spectrometry) method was developed and validated for simple and fast analysis of Pd/Pt-based drugs in 11 distinct biological matrices (adipose tissue, muscle, liver, kidney, spleen, testis, heart, lungs, brain, blood and serum). The critical variables affecting sample preparation and Pd/Pt extraction were optimized using two-level (2k) factorial and central composite designs. Biological samples (50 mg) were digested in closed tubes with a screw cap, using a 3 : 1 (v/v) mixture of nitric acid (900 µL) and hydrochloric acid (300 µL) for 60 min in a 90 °C water bath. Full method validation using in-house materials showed a LOD of 0.001 µg L-1, linear dynamic range from 0.025-10 µg L-1 (R2 = 0.9999 for Pd; R2 = 0.9998 for Pt), good repeatability (CV: 0.02-1.9%) and intermediate precision (CV: 0.52-1.53%) for both the studied metals. The accuracy ranged from 83.5-105.1% considering microwave-assisted digestion as the reference method. The developed and validated method allows the processing of hundreds of biological samples simultaneously, with low reagent and sample consumption. Therefore, the method is highly suitable for analysis of novel Pd/Pt-based drugs in pharmaco-toxicokinetic and biodistribution animal studies that involve a large number of multi-organ samples.


Assuntos
Paládio , Preparações Farmacêuticas , Animais , Masculino , Espectrometria de Massas , Platina , Distribuição Tecidual
13.
Struct Dyn ; 7(5): 054701, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32923512

RESUMO

The transition from normal to malignant state in human cells is still a poorly understood process. Changes in the dynamical activity of intracellular water between healthy and cancerous human cells were probed as an innovative approach for unveiling particular features of malignancy and identifying specific reporters of cancer. Androgen-unresponsive prostate and triple-negative breast carcinomas were studied as well as osteosarcoma, using the technique of quasi-elastic neutron scattering. The cancerous cells showed a considerably higher plasticity relative to their healthy counterparts, this being more significant for the mammary adenocarcinoma. Also, the data evidence that the prostate cancer cells display the highest plasticity when compared to triple-negative mammary cancer and osteosarcoma, the latter being remarkably less flexible. Furthermore, the results suggest differences between the flexibility of different types of intracellular water molecules in normal and cancerous cells, as well as the number of molecules involved in the different modes of motion. The dynamics of hydration water molecules remain virtually unaffected when going from healthy to cancer cells, while cytoplasmic water (particularly the rotational motions) undergoes significant changes upon normal-to-cancer transition. The results obtained along this study can potentially help to understand the variations in cellular dynamics underlying carcinogenesis and tumor metastasis, with an emphasis on intracellular water.

14.
Sensors (Basel) ; 20(2)2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31963186

RESUMO

Advances in research in Cultural Heritage see increasing application of a multidisciplinary approach and the combined use of physical and chemical characterization of artefacts that can be used to define their structure and their state of conservation, also providing valuable information in selecting the most suitable microclimatic conditions for the exhibition environment. This approach provides a platform for a synergic collaboration amongst researchers, restorers, conservators, and archaeologists. Existing state-of-the-art technologies for neutron-based methods are currently being applied to the study of objects of historical and cultural interest in several neutron-beam facilities around the world. Such techniques are non-invasive and non-destructive and are, therefore, ideal to provide structural information about artefacts, such as their composition, presence of alterations due to the environmental conditions, inclusions, structure of the bulk, manufacturing techniques, and elemental composition, which provide an overall fingerprint of the object's characteristics, thanks to the nature of the interaction of neutrons with matter. Here, we present an overview of the main neutron methods for the characterization of materials of interest in Cultural Heritage and we provide a brief introduction to the sensors and detectors that are used in this framework. We conclude with some case studies underlining the impact of these applications in different archaeological and historical contexts.

15.
Bioprocess Biosyst Eng ; 43(2): 359, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31584123

RESUMO

Unfortunately, in the "How to Cite as" section, the given and the family name of the author was incorrectly published, the correct name is Lladó Maldonado. S.

16.
Sci Adv ; 5(6): eaaw1292, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31259242

RESUMO

Burned skeletal remains are abundant in archaeological and paleontological sites, the result of fire or of ancient funerary practices. In the burning process, the bone matrix suffers structural and dimensional changes that interfere with the reliability of available osteometric methods. Recent studies showed that these macroscopic changes are accompanied by microscopic variations are reflected in vibrational spectra. An innovative integrated approach to the study of archaeological combusted skeletal remains is reported here, where the application of complementary vibrational spectroscopic techniques-INS (inelastic neutron scattering), FTIR (Fourier transform infrared), and micro-Raman-enables access to the complete vibrational profile and constitutes the first application of neutron spectroscopy to ancient bones. Comparison with data from modern human bones that were subjected to controlled burning allowed identification of specific heating conditions. This pioneering study provides archaeologists and anthropologists with relevant information on past civilizations, including regarding funerary, burial, and cooking practices and environmental settings.


Assuntos
Osso e Ossos/química , Difração de Nêutrons , Espectroscopia de Infravermelho com Transformada de Fourier , Arqueologia/história , Restos Mortais , Cremação , Fêmur/química , Fíbula/química , História Antiga , História Medieval , Humanos , Úmero/química , Espalhamento a Baixo Ângulo , Análise Espectral Raman
17.
Bioprocess Biosyst Eng ; 42(6): 953-961, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30810809

RESUMO

Bioreactors at the microliter scale offer a promising approach to accelerate bioprocess development. Advantages of such microbioreactors include a reduction in the use of expensive reagents. In this study, a chemostat operation mode of a cuvette-based microbubble column bioreactor made of polystyrene (working volume of 550 µL) was demonstrated. Aeration occurs through a nozzle (Ø ≤ 100 µm) and supports submerged whole-cell cultivation of Staphylococcus carnosus. Stationary concentrations of biomass and glucose were determined in the dilution rate regime ranging from 0.12 to 0.80 1/h with a glucose feed concentration of 1 g/L. For the first time, reaction kinetics of S. carnosus were estimated from data obtained from continuous cultivation. The maximal specific growth rate (µmax = 0.824 1/h), Monod constant (KS = 34 × 10- 3gS/L), substrate-related biomass yield coefficient (YX/S = 0.315 gCDW/gS), and maintenance coefficient (mS = 0.0035 gS/(gCDW·h)) were determined. These parameters are now available for further studies in the field of synthetic biology.


Assuntos
Biomassa , Reatores Biológicos/microbiologia , Staphylococcus/crescimento & desenvolvimento
18.
Ann Biomed Eng ; 47(4): 1153-1164, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30710185

RESUMO

This study analyzes the effects of the Rapha® system, which employs red light therapy (RLT) and a natural latex biomembrane in the healing of neuropathic ulcers associated with the diabetic foot. We conducted a randomized, controlled, blinded clinical trial with 15 participants that were divided into three groups (GI, GII and GIII): (i) Rapha® system application by the participant and a health professional at home, with clinical status evaluation every 2 weeks at the hospital (GI); (ii) standard protocol used in Brazil, performed by a health professional at the hospital (GII; control); and (iii) the Rapha® system applied by the participant at home and clinical status evaluation every 2 weeks at the hospital (GIII). We used image processing techniques on photographic recordings of the lesions, and several statistical tests were used to analyze the data, allowing for the comparison of the average results for all groups. The average healing rates of GI, GII, and GIII were 77.0, 51.4, and 80%, respectively. The granulation tissue evaluation indicated a higher efficacy in the tissue repair of lesions treated with the Rapha® system. In conclusion, the Rapha® system proved to be an effective healing system, even when self-applied at the patient's home.


Assuntos
Bandagens , Pé Diabético/terapia , Látex , Membranas Artificiais , Fototerapia , Cicatrização , Idoso , Pé Diabético/patologia , Pé Diabético/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
RSC Adv ; 9(63): 36640-36648, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-35539083

RESUMO

The first neutron diffraction study of human burned bone is reported, aiming at a comprehensive elucidation of the heat-induced bone diagenesis process. Chemical and crystallinity changes were probed in different types of bone (femur, humerus and tibia) upon heating to different maximum temperatures (from 400 to 1000 °C, under aerobic conditions). Fourier transform infrared spectroscopy has provided valuable complementary information. Noticeable crystallographic and domain size variations were detected, mainly between 700 and 900 °C, the high temperature interval (>700 °C) corresponding to an organized, highly symmetric inorganic bone matrix, virtually devoid of carbonates and organic constituents, while the lower range (<700 °C) revealed a considerably lower crystallinity associated with the presence of carbonates, lipids and collagen. This work contributes to a better understanding of heat-induced changes in bone and is therefore relevant for archaeology, biomaterials and forensic science.

20.
Molecules ; 24(1)2018 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-30586854

RESUMO

In the present study, we developed a green epoxidation approach for the synthesis of the diastereomers of (-)-isopulegol benzyl ether epoxide using molecular oxygen as the oxidant and a hybrid manganese(III)-porphyrin magnetic reusable nanocomposite as the catalyst. High activity, selectivity, and stability were obtained, with up to four recycling cycles without the loss of activity and selectivity for epoxide. The anticancer effect of the newly synthesized isopulegol epoxide diastereomers was evaluated on a human osteosarcoma cell line (MG-63); both diastereomers showed similar in vitro potency. The measured IC50 values were significantly lower than those reported for other monoterpene analogues, rendering these epoxide isomers as promising anti-tumor agents against low prognosis osteosarcoma.


Assuntos
Antineoplásicos/farmacologia , Biomimética , Fenômenos Magnéticos , Metaloporfirinas/química , Nanocompostos/química , Osteossarcoma/patologia , Antineoplásicos/síntese química , Antineoplásicos/química , Varredura Diferencial de Calorimetria , Catálise , Linhagem Celular Tumoral , Monoterpenos Cicloexânicos , Compostos de Epóxi/síntese química , Compostos de Epóxi/química , Humanos , Manganês/química , Nanocompostos/ultraestrutura , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Estereoisomerismo , Terpenos/síntese química , Terpenos/química , Terpenos/farmacologia , Termogravimetria
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