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1.
Nat Commun ; 10(1): 2741, 2019 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-31227695

RESUMO

Knowing how biomarker levels vary within biological fluids over time can produce valuable insight into tissue physiology and pathology, and could inform personalised clinical treatment. We describe here a wearable sensor for monitoring biomolecule levels that combines continuous fluid sampling with in situ analysis using wet-chemical assays (with the specific assay interchangeable depending on the target biomolecule). The microfluidic device employs a droplet flow regime to maximise the temporal response of the device, using a screw-driven push-pull peristaltic micropump to robustly produce nanolitre-sized droplets. The fully integrated sensor is contained within a small (palm-sized) footprint, is fully autonomous, and features high measurement frequency (a measurement every few seconds) meaning deviations from steady-state levels are quickly detected. We demonstrate how the sensor can track perturbed glucose and lactate levels in dermal tissue with results in close agreement with standard off-line analysis and consistent with changes in peripheral blood levels.


Assuntos
Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas/instrumentação , Sistemas Automatizados de Assistência Junto ao Leito , Pele/química , Dispositivos Eletrônicos Vestíveis , Biomarcadores/análise , Glicemia/análise , Desenho de Equipamento , Glucose/análise , Voluntários Saudáveis , Humanos , Ácido Láctico/análise , Microdiálise/instrumentação , Microdiálise/métodos , Técnicas Analíticas Microfluídicas/métodos
2.
J Food Sci ; 84(7): 1799-1805, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31218694

RESUMO

Defatting of seabass skins using pulsed electric field (PEF)-assisted process at different electric field strengths (16 and 24 kV/cm) and times (36, 72, and 108 ms) in combination with porcine pancreas lipase (PPL) at 25 U/g dry matter was investigated. PEF-treated skin at 24 kV/cm for 72 ms followed by PPL treatment removed 86.93% lipids. PEF-treated skin was further optimized for lipid reduction by response surface methodology. Central composite design was adopted to establish treatments based on two independent variables, involving PPL concentration (30 to 55 U/g dry matter) and hydrolysis time (60 to 180 min). Second-order polynomial model was used for predicting the response. The highest lipid removal (91.96 ± 1.70%) was attained when the optimal condition (42.36 PPL units/g dry skin matter for 139.78 min) was used. The experiment value was in accordance with the predicted value. PEF-PPL-treated skin had lower monounsaturated and polyunsaturated fatty acids than the solvent-extracted skin (P < 0.05). When PEF-PPL-treated skin was hydrolyzed using papain at 0.30 U/g dry matter, lower fishy odor/flavor of resulting hydrolyzed collagen (PEF-PPL-HC) was found than other samples (P < 0.05). Lower total volatile compounds were also obtained in PEF-PPL-HC sample. Thus, the use of PEF pretreatment along with PPL before papain hydrolysis effectively prevented the formation of fishy odor/flavor in hydrolyzed collagen from seabass skin. PRACTICAL APPLICATION: Fishy odor/flavor caused by lipid oxidation of fish skin hydrolysates limits their applications in foods. Defatting process is the significant step for skin pretreatment. Although several methods could remove lipids from fish skins, either by lipase or solvent extraction, fishy odor/flavor is still detected in hydrolysate. Pulsed electric field-assisted process in combination with porcine lipase is another approach that can be used to enhance efficiency via electroporation, causing the loosened skin matrix and facilitating the migration of lipase into the skin. Consequently, the resulting hydrolysate might have the lowered fishy odor/flavor and could be used in foods, especially for fortification.


Assuntos
Manipulação de Alimentos/métodos , Lipase/química , Lipídeos/química , Pele/química , Animais , Bass , Biocatálise , Colágeno/química , Ácidos Graxos Insaturados/química , Proteínas de Peixes/química , Manipulação de Alimentos/instrumentação , Humanos , Odorantes/análise , Oxirredução , Suínos , Paladar
3.
Talanta ; 201: 58-64, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31122461

RESUMO

The fabrication of flexible and transparent Surface Enhanced Raman Scattering (SERS) substrates enabling fast, sensitive and on site detection is relevant for the practical application of SERS for real world analysis, such as food safety and organic pollutants monitoring. In this work novel Ag NPs/PDMS composites were fabricated and employed for the SERS detection of food contaminants directly on food surfaces. Ag NPs/PDMS composites were obtained by self-assembly of organic Ag nanoparticle solutions on flexible PDMS surfaces. Preliminary evaluation of the suitability of Ag NPs/PDMS probes for SERS analysis showed that composites were characterized by a SERS enhancement factor (EF) of 3.1 × 105, good stability and resistance to harsh conditions as well as good uniformity and batch to bach reproducibility. The "sticky" nature of Ag NPs/PDMS composites was exploited to "paste" them on irregular analytical surfaces, thus enabling the detection in situ of food contaminant crystal violet (CV) and pesticide thiram, respectively. Specifically, CV and thiram concentrations as low as 1 × 10-7 M and 1 × 10-5 M were measured on contaminated fish skin and orange peel, respectively. Furthermore, efficient SERS detection by micro-extraction of CV from fish skin and thiram from fruit surfaces was achieved, showing the analytical versatility of the fabricated SERS composites.


Assuntos
Contaminação de Alimentos/análise , Nanopartículas Metálicas/química , Nanocompostos/química , Silicones/química , Prata/química , Animais , Anti-Infecciosos Locais/análise , Citrus sinensis/química , Peixes , Fungicidas Industriais/análise , Violeta Genciana/análise , Reprodutibilidade dos Testes , Silicones/síntese química , Pele/química , Análise Espectral Raman/métodos , Tiram/análise
4.
Chemosphere ; 229: 611-617, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31102916

RESUMO

Since tannery workers in developing countries are chronically exposed to high levels of chromium (Cr), there are serious concerns about health problems. However, there has been limited study in which Cr levels were measured in tannery workers, who are chronically exposed to Cr. Our preliminary inspection showed that there was hyperpigmented skin in tannery workers. We therefore investigated the correlation between skin pigmentation levels digitally evaluated as L* values by using a reflectance spectrophotometer and Cr levels in skin appendages in 100 male tannery workers and in 49 male non-tannery workers in Bangladesh. Digitalized skin pigmentation levels of the face and feet in addition to Cr levels in hair and toenails in tannery workers were significantly higher than those in non-tannery workers in our univariate analysis. Spearman's rank correlation coefficient analysis showed significant correlation between duration of tannery work (years) and Cr levels in hair (r = 0.62) and toenails (r = 0.61). Our multivariate analysis also showed that Cr levels in hair and toenails were significantly correlated with digitalized skin pigmentation levels of the face and feet in addition to duration of tannery work in all participants. Thus, our results showed the development of hyperpigmented skin in tannery workers. Our results also suggested that hyperpigmented skin could be a useful diagnostic marker for chronic exposure to Cr. Furthermore, cutaneous L* value might be a convenient marker for detection of chronic Cr poisoning, since the digitalized values enable objective evaluation of skin pigmented levels by general people as well as dermatologists.


Assuntos
Cromo/análise , Hiperpigmentação/induzido quimicamente , Doenças Profissionais/induzido quimicamente , Exposição Ocupacional/efeitos adversos , Adulto , Idoso , Bangladesh , Cromo/toxicidade , Face , , Cabelo/química , Humanos , Hiperpigmentação/patologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Unhas/química , Pele/química , Espectrofotometria/métodos , Curtume
5.
J Mol Model ; 25(5): 140, 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-31041534

RESUMO

Skin provides excellent protection against the harsh external environment and foreign substances. The lipid matrix of the stratum corneum, which contains various kinds of ceramides, plays a major role in the barrier function of the skin. Here we report a study of the effects of ceramide type on the structural and transport properties of ceramide bilayers using molecular dynamics (MD) simulations. Specifically, the effects of headgroup chemistry (number and positions of hydroxyl groups) and tail structure (unsaturation of the sphingoid moiety) on the structural and transport properties of various ceramide bilayers at 310 K were analyzed. Theoretical results for structural properties such as area per lipid, bilayer thickness, lateral arrangement, order parameter, and hydrogen bonding are reported here and compared with corresponding experimental data. Our study revealed that the presence of a double bond disrupts the bilayer packing, which leads to a low area compressibility modulus, a large area per lipid, and low bilayer thickness. Furthermore, the effect of structural changes on water permeation was studied using steered MD simulations. Water permeation was found to be influenced by headgroup polarity, chain packing, and the ability of the water to hydrogen bond with the ceramides. The molecular-level information obtained from the current study should aid the design of mixed bilayer systems with desired properties and provide the basis for the development of higher order coarse-grained models.


Assuntos
Ceramidas/química , Bicamadas Lipídicas/química , Simulação de Dinâmica Molecular , Pele/química , Ligações de Hidrogênio , Lipídeos/química , Estrutura Molecular , Análise Espectral , Relação Estrutura-Atividade
6.
Environ Health Prev Med ; 24(1): 36, 2019 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-31101002

RESUMO

BACKGROUND: Melanin is detectable in various sense organs including the skin in animals. It has been reported that melanin adsorbs toxic elements such as mercury, cadmium, and lead. In this study, we investigated the adsorption of molybdenum, which is widely recognized as a toxic element, by melanin. METHODS: Molybdenum level of the mouse skin was measured by inductively coupled plasma mass spectrometry. The pigmentation level of murine skin was digitalized as the L* value by using a reflectance spectrophotometer. An in vitro adsorption assay was performed to confirm the interaction between molybdenum and melanin. RESULTS: Our analysis of hairless mice with different levels of skin pigmentation showed that the level of molybdenum increased with an increase in the level of skin pigmentation (L* value). Moreover, our analysis by Spearman's correlation coefficient test showed a strong correlation (r = - 0.9441, p < 0.0001) between L* value and molybdenum level. Our cell-free experiment using the Langmuir isotherm provided evidence for the adsorption of molybdenum by melanin. The maximum adsorption capacity of 1 mg of synthetic melanin for molybdenum was 131 µg in theory. CONCLUSION: Our in vivo and in vitro results showed a new aspect of melanin as an adsorbent of molybdenum.


Assuntos
Melaninas/química , Molibdênio/química , Poluentes Químicos da Água/química , Adsorção , Animais , Melaninas/metabolismo , Camundongos , Camundongos Pelados , Camundongos Transgênicos , Molibdênio/metabolismo , Molibdênio/farmacologia , Pele/química , Pele/efeitos dos fármacos , Pigmentação da Pele/efeitos dos fármacos , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/farmacologia
7.
Mar Drugs ; 17(5)2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31052462

RESUMO

Collagen was extracted from bigeye tuna (Thunnus obesus) skins by salting-out (PSC-SO) and isoelectric precipitation (PSC-IP) methods. The yield of the PSC-IP product was approximately 17.17% (dry weight), which was greater than the yield obtained from PSC-SO (14.14% dry weight). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis indicated that collagen from bigeye tuna skin belongs to collagen type I. Inductively coupled plasma mass spectrometry results indicate that the heavy metal abundance in PSC-IP was lower than the maximum acceptable amounts according to Chinese regulatory standards. In addition, results from a methylthiazolyldiphenyl-tetrazolium bromide assay and an in vitro scratch assay demonstrated that PSC-IP could promote the proliferation and migration of NIH-3T3 fibroblasts. Overall, results suggest PSC-IP could be used to rapidly extract collagen from marine by-products instead of traditional salting-out methods. Collagen from bigeye tuna skin may also have strong potential for cosmetic and biomedical applications.


Assuntos
Colágeno/análise , Colágeno/isolamento & purificação , Proteínas de Peixes/análise , Proteínas de Peixes/isolamento & purificação , Animais , Ensaios de Migração Celular , Proliferação de Células , Colágeno/química , Colágeno Tipo I , Proteínas de Peixes/química , Camundongos , Células NIH 3T3/efeitos dos fármacos , Pele/química , Pele/metabolismo , Solubilidade , Atum
8.
J Agric Food Chem ; 67(16): 4671-4678, 2019 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-30929424

RESUMO

Collagen-derived hydroxyproline (Hyp)-containing oligopeptides, known to have various physiological functions, are detected in blood at markedly higher concentrations after oral ingestion of collagen hydrolysate. Monitoring the absorption and metabolism of the bioactive peptides is essential to investigate the beneficial effects of collagen hydrolysate. We previously developed an internal standard mixture by sequential protease digestion of stable isotope-labeled collagen, which enabled highly accurate quantitation of collagen-derived oligopeptides by liquid chromatography-mass spectrometry (LC-MS). However, the use of proteases caused a profound imbalance in the generated peptides. Here, we employed partial acid hydrolysis to achieve more efficient and balanced peptide generation. Various stable isotope-labeled oligopeptides were detected after 0.5 h acid hydrolysis, and marked enhancement of peptide generation compared with the previous enzymatic method was observed, especially for Hyp-Gly (27.8 ± 0.6 ng/µg vs 0.231 ± 0.02 ng/µg). The acid hydrolysate was then heated to generate labeled cyclic dipeptides. Using the novel internal standard mixture in LC-MS, we were able to simultaneously quantitate 23 collagen-derived oligopeptides in human plasma and urine after oral administration of collagen hydrolysate.


Assuntos
Colágeno/química , Colágeno/metabolismo , Ácidos/química , Adulto , Animais , Isótopos de Carbono/análise , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , Marcação por Isótopo , Masculino , Isótopos de Nitrogênio/análise , Peptídeos/química , Peptídeos/metabolismo , Hidrolisados de Proteína/química , Hidrolisados de Proteína/metabolismo , Pele/química , Suínos , Espectrometria de Massas em Tandem , Adulto Jovem
9.
Forensic Sci Int ; 300: e24-e30, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31023496

RESUMO

Realgar (arsenic sulfide) is widely used in combination with other herbs as Chinese patent medicine to treat a variety of diseases in China. As a mineral arsenic, its mild toxicity was also well known. Longtime over-dose usage or wrongly oral intake of realgar can cause chronic arsenic poisoning and/or death, but acute fatal arsenic poisoning resulted from short-term dermal use of realgar-containing medicine was very rare. Here, we present the case of a 35-year-old Chinese man, who was diagnosed with severe psoriasis and died of fatal acute arsenic poisoning after he applied a local folk prescription ointment containing mainly the realgar to the affected skin for about 4 days. The autopsy showed multiple punctate hemorrhages over the limbs, pleural effusion, edematous lungs with consolidation, mild myocardial hypertrophy and normal-looking kidneys. The histopathological examination of renal tissue showed severe degeneration, necrosis and desquamation of renal tubular epithelial cells, presence of protein cast and a widened edematous interstitium with interstitial fibrosis. The presence of arsenic in large amount in the ointment (about 6%), in blood (1.76 µg/mL), and in skin (4.71 µg/g), were confirmed analytically. We also provide the clinical records of the deceased and briefly reviewed 7 similar cases in literature (6 in Chinese and 1 in English) in the past 30 years in China.


Assuntos
Intoxicação por Arsênico/etiologia , Medicina Tradicional Chinesa/efeitos adversos , Sulfetos/envenenamento , Administração Tópica , Adulto , Intoxicação por Arsênico/patologia , Arsenicais/administração & dosagem , Arsenicais/análise , China , Hemorragia/patologia , Humanos , Rim/patologia , Pulmão/patologia , Masculino , Pomadas , Derrame Pleural/patologia , Pele/química , Sulfetos/administração & dosagem , Sulfetos/análise
10.
Int J Pharm ; 563: 384-394, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-30959237

RESUMO

Ceramides (Cers) are significant constituents of the stratum corneum (SC), the uppermost skin layer responsible for skin barrier properties. Cers are a heterogeneous group of lipids whose mutual interactions are still unclear. To better understand these interactions, we characterized model membranes containing stearic acid, cholesterol, cholesterol sulfate and one or more of the following ceramides: N-stearoyl-sphingosine (CerNS), N-stearoyl-phytosphingosine (CerNP) and N-(2-hydroxy)stearoyl-phytosphingosine (CerAP). Small angle X-ray scattering and FTIR spectroscopy were used to study lipid arrangement, phase separation and thermotropic behaviour. In the one-Cer systems, the membranes with CerNP showed strong hydrogen bonding and significant phase separation, even after phase transition, while the systems containing CerAP and CerNS had increased lipid miscibility. The multi-Cer systems exhibited different behaviour. In particular, the membrane containing all three Cers was a highly miscible system with narrow one-step phase transition, which, of all the studied samples, occurred at the lowest temperatures. Our results show that even a small variation in Cer structure results in substantially different phase behaviour, which is further affected by the presence of other Cer subclasses. Interestingly, the phase behaviour of the most complex three-Cer system was simpler than that of the others, highlighting the importance of lipid diversity in real SC.


Assuntos
Ceramidas/química , Lipídeos de Membrana/química , Esfingosina/análogos & derivados , Hidroxilação , Transição de Fase , Pele/química , Esfingosina/química , Temperatura Ambiente
11.
Rapid Commun Mass Spectrom ; 33(16): 1336-1343, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31034697

RESUMO

RATIONALE: Authentication of fish is of importance in the view of toxins, allergen warnings and economic fraud control. Traditional methods in the authentication of fish, e.g. morphological, genetic and proteomic analysis, are either at low throughput or at high-cost. METHODS: A high-throughput matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS)-based approach was developed to analyze biomaterials from fish skin, and mass spectra from different fish species were compared by chemometric methods to differentiate fish species. RESULTS: A total of 51 fish samples were used to generate more than 150 fingerprinting mass spectra. The fish belonging to the same genus can be identified at species level. A mass spectral database of different fishes can be built as reference for authentication. The analysis can be performed based on micrograms of fish-skin sample and accomplished in 1-3 hours. CONCLUSIONS: The developed strategy holds potential to be applied to fish authentication in the fishing industry and as a scientific method to avoid mislabeling. It has promise to be practically used for fast and effective identification of closely related fish species to guarantee the quality of fishery products to consumers.


Assuntos
Proteínas de Peixes , Peixes/classificação , Proteômica/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Animais , Proteínas de Peixes/análise , Proteínas de Peixes/química , Análise de Componente Principal , Pele/química
12.
Biomed Chromatogr ; 33(8): e4557, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30990899

RESUMO

In our study, a method for the determination for tazarotene and betamethasone dipropionate in human tissue-engineered skin was established. Tazarotene gel, betamethasone dipropionate cream or a combination cream was administered to the skin. Then the skin was taken off at 0.25, 0.75, 1.75, 3, 5, 8, 12, 24, 36, 48 h time points after the residual drug was removed. The concentrations of tazarotene, betamethasone dipropionate and their major metabolites in skin were determined by LC-MS. Tazarotene and tazarotenic acid were detected in the concentration range of 2-200 µg/mL with an LLOQ of 2 µg/mL. Betamethasone dipropionate was detected in the concentration range 0.5-300 µg/mL with an LLOQ of 0.5 µg/mL, and betamethasone was detected at 2-200 µg/mL with an LLOQ of 2 µg/mL. The intra- and inter-day precisions of the four analytes in the skin homogenate were all <15% (RSD, %). The results showed that tazarotene could be metabolized to tazarotenic acid and betamethasone dipropionate could be metabolized to betamethasone in tissue-engineered skin. The results also revealed that this method was suitable for the simultaneous determination of tazarotene, betamethasone dipropionate and their metabolites in tissue-engineered skin.


Assuntos
Betametasona/análogos & derivados , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Ácidos Nicotínicos/análise , Betametasona/análise , Betametasona/química , Betametasona/metabolismo , Betametasona/farmacocinética , Técnicas de Cultura de Células , Linhagem Celular , Humanos , Limite de Detecção , Modelos Lineares , Modelos Biológicos , Ácidos Nicotínicos/química , Ácidos Nicotínicos/metabolismo , Ácidos Nicotínicos/farmacocinética , Reprodutibilidade dos Testes , Pele/química , Pele/metabolismo , Engenharia Tecidual
13.
Mar Drugs ; 17(4)2019 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-31013895

RESUMO

A previous report indicated that collagen hydrolysate fraction (F7) from Spanish mackerel (Scomberomorous niphonius) skins showed high reducing power and radical scavenging activities on 2,2-Diphenyl-1-picrylhydrazyl (DPPH) (EC50 value of 1.57 mg/mL) and hydroxyl (EC50 value of 1.20 mg/mL). In this work, eight peptides were isolated from F7 and identified as Gly-Pro-Tyr (GPY, 335.31 Da), Gly-Pro-Thr-Gly-Glu (GPTGE, 459.47 Da), Pro-Phe-Gly-Pro-Asp (PFGPD, 531.52 Da), Gly-Pro-Thr-Gly-Ala-Lys (GPTGAKG, 586.65 Da), Pro-Tyr-Gly-Ala-Lys-Gly (PYGAKG, 591.69 Da), Gly-Ala-Thr-Gly-Pro-Gln-Gly (GATGPQG, 586.61 Da), Gly-Pro-Phe-Gly-Pro-Met (GPFGPM, 604.73 Da), and Tyr-Gly-Pro-Met (YGPM, 466.50 Da), respectively. Among them, PFGPD, PYGAKG, and YGPM exhibited strong radical scavenging activities on DPPH (EC50 values of 0.80, 3.02, and 0.72 mg/mL for PFGPD, PYGAKG, and YGPM, respectively), hydroxyl (EC50 values of 0.81, 0.66, and 0.88 mg/mL for PFGPD, PYGAKG, and YGPM, respectively), superoxide anion (EC50 values of 0.91, 0.80, and 0.73 mg/mL for PFGPD, PYGAKG, and YGPM, respectively), and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) cation (EC50 values of 0.86, 1.07, and 0.82 mg/mL for PFGPD, PYGAKG, and YGPM, respectively) in a positive concentration-activity relationship. Furthermore, PFGPD, PYGAKG, and YGPM could effectively reduce Fe3+ to Fe2+ and inhibit lipid peroxidation. Hence, eight collagen peptides from hydrolysate of Spanish mackerel skins might be served as antioxidant candidates for various industrial applications.


Assuntos
Antioxidantes/química , Colágeno/química , Colágeno/farmacologia , Peptídeos/química , Peptídeos/farmacologia , Perciformes/metabolismo , Pele/química , Animais , Antioxidantes/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Hidrolisados de Proteína/metabolismo , Superóxidos/metabolismo
14.
Rapid Commun Mass Spectrom ; 33(15): 1277-1285, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31034695

RESUMO

RATIONALE: Stable isotope analysis is used to understand the foraging habits and movements of a diverse set of organisms. Variability in stable isotope ratios among tissues derived from the same animal makes it difficult to compare data among study results in which different tissue types are evaluated. Isotopic relationships between two green turtle (Chelonia mydas) tissue types, skin and unhatched egg contents are unknown. Similarly, few data exist to evaluate the influence of time elapsed after oviposition (as a proxy for decomposition) on isotopic variability among unhatched eggs within the same nest. METHODS: Skin and unhatched egg contents were collected from 69 adult female green turtles and associated nests at the Archie Carr National Wildlife Refuge in Florida, USA. Values of δ13 C, δ15 N, and δ34 S were measured for both tissue types using a continuous flow isotope ratio mass spectrometer. Standardized major-axis (SMA) regression was used to generate conversion equations of carbon, nitrogen, and sulfur isotope ratios between the two tissue types. Model selection frameworks consisting of single-factor linear models were employed per isotope ratio to assess how egg time-in-nest affected intraclutch isotopic variability. RESULTS: Conversion equations for all three isotope ratios indicated significant relationships between skin and unhatched egg values, although model fits were lower than found in some studies examining similar patterns in other marine turtle species. The probability of increased intraclutch variability was significantly higher among eggs collected at longer intervals after deposition. CONCLUSIONS: This study reports the first-ever δ13 C and δ15 N conversion equations between skin and unhatched eggs for green turtles, and the first δ34 S conversion equation for any marine turtle species. SMA regression was used to directly convert tissue values bidirectionally, unlike equations generated using ordinary least-squares regression. Issues with increased intraclutch variability at later excavation dates highlight the importance of collecting unhatched eggs as soon as possible after hatchling emergence.


Assuntos
Óvulo/química , Pele/química , Animais , Animais Selvagens , Isótopos de Carbono/análise , Ecossistema , Feminino , Modelos Lineares , Espectrometria de Massas , Isótopos de Nitrogênio/análise , Oviposição , Isótopos de Enxofre/análise , Tartarugas/fisiologia
15.
Food Chem ; 287: 273-279, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-30857699

RESUMO

Growing demand for gelatin has increased interest in using alternative raw materials. In this study, different animal skins; namely frog, tuna and chicken skins; were utilized in gelatin extraction by previously optimized extraction procedures. Quality characteristics and functional properties of the resultant gelatins were comparatively investigated. Frog skin gelatin had the highest protein content with 77.8% while the highest hydroxyproline content was found in chicken skin gelatin with 6.4%. Frog skin gelatin showed a significantly higher melting point (42.7 °C) compared to tuna and chicken gelatins. Bloom value was also significantly higher in frog skin gelatin compared to that of chicken and tuna skin gelatins. Results showed that processing waste like skins of different animals may present opportunities in gelatin production as high quality alternatives. This study may help the industry by providing one hand comparable data over potentially significant sources.


Assuntos
Galinhas , Gelatina/química , Rana esculenta , Pele/química , Atum , Animais , Gelatina/análise , Hidroxiprolina/análise , Temperatura de Transição
16.
Forensic Sci Int ; 298: 48-57, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30877948

RESUMO

This study investigated the prevalence of eight OGSR compounds in a civilian and a police population. Specimens were collected from the hands and sleeves of 122 civilians and 115 individuals working in police services using carbon stubs. Data was acquired using liquid chromatography coupled to tandem mass spectrometry. Results indicated a non-negligible prevalence in the civilian sample, with 18% of the 122 civilians sampled having one or more OGSR related compounds on their hands and 11.5% on their wrists or sleeves. For the police population, the prevalence was logically higher than for civilians, with 36.5% of the hand specimens and 33% of the wrist specimens positive for one or more compounds. A higher prevalence was expected for the second population due to the possession of service weapons regularly used during shooting exercises. These results demonstrate that the presence of one OGSR compound is not a rare occurrence, even in a civilian population. Considering the results of this research together with information on alternative sources of the targeted OGSR compounds can serve as a basis for OGSR interpretation in casework.


Assuntos
Armas de Fogo , Polícia , Pele/química , Antimônio/análise , Bário/análise , Cromatografia Líquida , Vestuário , Humanos , Chumbo/análise , Suíça , Espectrometria de Massas em Tandem
17.
Mar Drugs ; 17(3)2019 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-30813606

RESUMO

The aim of this study is to investigate the physicochemical properties, biosafety, and biocompatibility of the collagen extract from the skin of Nile tilapia, and evaluate its use as a potential material for biomedical applications. Two extraction methods were used to obtain acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) from tilapia skin. Amino acid composition, FTIR, and SDS-PAGE results showed that ASC and PSC were type I collagen. The molecular form of ASC and PSC is (α1)2α2. The FTIR spectra of ASC and PSC were similar, and the characteristic peaks corresponding to amide A, amide B, amide I, amide II, and amide III were 3323 cm-1, 2931 cm-1, 1677 cm-1, 1546 cm-1, and 1242 cm-1, respectively. Denaturation temperatures (Td) were 36.1 °C and 34.4 °C, respectively. SEM images showed the loose and porous structure of collagen, indicting its physical foundation for use in applications of biomedical materials. Negative results were obtained in an endotoxin test. Proliferation rates of osteoblastic (MC3T3E1) cells and fibroblast (L929) cells from mouse and human umbilical vein endothelial cells (HUVEC) were increased in the collagen-treated group compared with the controls. Furthermore, the acute systemic toxicity test showed no acute systemic toxicity of the ASC and PSC collagen sponges. These findings indicated that the collagen from Nile tilapia skin is highly biocompatible in nature and could be used as a suitable biomedical material.


Assuntos
Materiais Biocompatíveis/química , Ciclídeos , Colágeno Tipo I/química , Proteínas de Peixes/química , Animais , Materiais Biocompatíveis/isolamento & purificação , Linhagem Celular , Colágeno Tipo I/isolamento & purificação , Colágeno Tipo I/ultraestrutura , Proteínas de Peixes/isolamento & purificação , Proteínas de Peixes/ultraestrutura , Humanos , Concentração de Íons de Hidrogênio , Camundongos , Microscopia Eletrônica de Varredura , Pele/química , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier
18.
Mar Drugs ; 17(3)2019 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-30818811

RESUMO

The objective of this report was to investigate the isolation and recovery of different biocompounds and bioproducts from wastes (skins and heads) that were obtained from five species discarded by fishing fleets (megrim, hake, boarfish, grenadier, and Atlantic horse mackerel). Based on chemical treatments, enzymatic hydrolysis, and bacterial fermentation, we have isolated and produced gelatinous solutions, oils that are rich in omega-3, fish protein hydrolysates (FPHs) with antioxidant and antihypertensive activities, and peptones. FPHs showed degrees of hydrolysis higher than 13%, with soluble protein concentrations greater than 27 g/L and in vitro digestibilities superior to 90%. Additionally, amino acids compositions were always valuable and bioactivities were, in some cases, remarkable. Peptones that were obtained from FPHs of skin and the heads were demonstrated to be a viable alternative to expensive commercial ones indicated for the production of biomass, lactic acid, and pediocin SA-1 from Pediococcus acidilactici.


Assuntos
Produtos Biológicos/isolamento & purificação , Ácidos Graxos Ômega-3/isolamento & purificação , Peixes , Peptonas/isolamento & purificação , Hidrolisados de Proteína/isolamento & purificação , Animais , Anti-Hipertensivos/economia , Anti-Hipertensivos/isolamento & purificação , Anti-Hipertensivos/farmacologia , Antioxidantes/economia , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Bactérias/metabolismo , Produtos Biológicos/economia , Produtos Biológicos/farmacologia , Ácidos Graxos Ômega-3/economia , Ácidos Graxos Ômega-3/farmacologia , Fermentação , Pesqueiros/economia , Cabeça , Hidrólise , Peptonas/economia , Peptonas/farmacologia , Hidrolisados de Proteína/economia , Hidrolisados de Proteína/farmacologia , Pele/química , Espanha
19.
ACS Appl Mater Interfaces ; 11(14): 13608-13615, 2019 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-30868878

RESUMO

The human skin has inspired multimodal detection using smart devices or systems in fields including biomedical engineering, robotics, and artificial intelligence. Hairs of a high aspect ratio (AR) connected to follicles, in particular, detect subtle structural displacements by airflow or ultralight touch above the skin. Here, hairy skin electronics assembled with an array of graphene sensors (16 pixels) and artificial microhairs for multimodal detection of tactile stimuli and details of airflows (e.g., intensity, direction, and incident angle) are presented. Composed of percolation networks of graphene nanoplatelet sheets, the sensor array can simultaneously detect pressure, temperature, and vibration, all of which correspond to the sensing range of human tactile perceptions with ultrahigh response time (<0.5 ms, 2 kHz) for restoration. The device covered with microhairs (50 µm diameter and 300 µm height, AR = 6, hexagonal layout, and ∼4400/cm2) exhibits mapping of electrical signals induced by noncontact airflow and identifying the direction, incident angle, and intensity of wind to the sensor. For potential applications, we implement the hairy electronics to a sailing robot and demonstrate changes in locomotion and speed by detecting the direction and intensity of airflow.


Assuntos
Grafite/química , Cabelo/química , Robótica , Pele/química , Eletrônica , Humanos , Pressão , Tato
20.
Mar Drugs ; 17(3)2019 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-30866485

RESUMO

Recent animal studies found the potential of a collagen peptide derived from skate skin to have anti-obesity effects through the suppression of fat accumulation and regulation of lipid metabolism. However, no studies have yet been performed in humans. Here, this very first human randomized, placebo-controlled, and double-blinded study was designed to investigate the efficacy and tolerability of skate skin collagen peptides (SCP) for the reduction of body fat in overweight adults. Ninety healthy volunteers (17 men) aged 41.2 ± 10.4 years with a mean body mass index of 25.6 ± 1.9 kg/m² were assigned to the intervention group (IG), which received 2000 mg of SCP per day or to the control group (CG) given the placebo for 12 weeks and 81 (90%) participants completed the study. Changes in body fat were evaluated using dual energy X-ray absorptiometry as a primary efficacy endpoint. After 12 weeks of the trial, the percentage of body fat and body fat mass (kg) in IG were found to be significantly better than those of subjects in CG (-1.2% vs. 2.7%, p = 0.024 and -1.2 kg vs. 0.3 kg, p = 0.025). Application of SCP was well tolerated and no notable adverse effect was reported from both groups. These results suggest the beneficial potential of SCP in the reduction of body fat in overweight adults.


Assuntos
Fármacos Antiobesidade/uso terapêutico , Colágeno/uso terapêutico , Obesidade/tratamento farmacológico , Peptídeos/uso terapêutico , Administração Oral , Adulto , Animais , Fármacos Antiobesidade/química , Índice de Massa Corporal , Colágeno/química , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Peptídeos/química , Raias , Pele/química , Extratos de Tecidos/química , Extratos de Tecidos/uso terapêutico
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