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1.
ACS Omega ; 8(50): 47874-47882, 2023 Dec 19.
Article in English | MEDLINE | ID: mdl-38144060

ABSTRACT

Chromium-doped Ga2O3, with intense Cr3+-related red-infrared light emission, is a promising semiconductor material for optical sensors. This work constitutes a comprehensive study of the thermoluminescence properties of Cr-, Mg-codoped ß-Ga2O3 single crystals, both prior to and after proton irradiation. The thermoluminescence investigation includes a thorough analysis of measurements with different ß- irradiation doses used to populate the trap levels, with preheating steps to disentangle overlapping peaks (TM-TSTOP and initial rise methods) and finally by computationally fitting to a theoretical expression. At least three traps with activation energies of 0.84, 1.0, and 1.1 eV were detected. By comparison with literature reports, they can be assigned to different defect complexes involving oxygen vacancies and/or common contaminants/dopants. Interestingly, the thermoluminescence signal is enhanced by the proton irradiation while the type of traps is maintained. Finally, the pristine glow curve was recovered on the irradiated samples after an annealing step at 923 K for 10 s. These results contribute to a better understanding of the defect levels in Cr-, Mg-codoped ß-Ga2O3 and show that electrons released from these traps lead to Cr3+-related light emission that can be exploited in dosimetry applications.

2.
Mar Pollut Bull ; 186: 114419, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36525757

ABSTRACT

Multivariate analyses have been applied to the REE contents of three cores collected in the Tinto estuary, SW Spain, an extremely polluted area. Results indicate an extremely correlation between all REE, which behave as a single variable. A slight natural pollution peak and three anthropogenic pollution peaks are identified, related with the first mining activities, the Roman period and a recent intensive mining accompanied by a heavy industrial pollution. In all these peaks, the increase of Cu is parallel to that of MREE, which are configured as the best indicators of pollution among REE. Statistical analyses clearly differentiate four groups, each consisting of samples from different environments. Although grain size and this strong pollution alter the study of REE as environmental indicators, it is possible to recognise groups of samples with a common origin or to identify the surface extent of a given pollution peak.


Subject(s)
Metals, Rare Earth , Water Pollutants, Chemical , Spain , Estuaries , Water Pollutants, Chemical/analysis , Metals, Rare Earth/analysis , Environmental Pollution/analysis , Environmental Monitoring/methods
3.
Article in English | LILACS, VETINDEX | ID: biblio-1347994

ABSTRACT

A clinical case in which skin and hair color change occurred after sacrococcygeal epidural anesthesia in a nine-month-old Siamese cross queen undergoing ovariohysterectomy (OHE) is described. Six weeks after surgery, during a re-check, it was noted that in the sacrococcygeal region the color of the skin and new hair growth was dark with a color comparable to the color present on the body extremities (muzzle, pinnae, legs, and tail). The skin and new hair growth of the shaved abdomen presented a standard color. The key enzyme of the melanogenic pathway in mammals is tyrosinase (TYR), and the Siamese temperature-sensitive phenotype is the result of genetic mutations that makes TYR function thermolabile. The activity of TYR in these cats is limited to the extremities where the temperature is lower while pigment production is impaired in the other body areas. The trichotomy of the sacrococcygeal region performed during wintertime in an outdoor cat was probably the trigger for increased activity of TYR in this area promoting pigment production. The absence of the same alterations in the abdominal area may be justified by less exposure of that region to the external environment, as well as to the feline habits of sedentarism, that avoid significant cooling in these regions. This report highlights the importance of taking this type of occurrence into account when performing an epidural in the Siamese cat breed. Also, to avoid skin color change in this breed, the authors recommend a midline abdominal instead of a flank approach to perform OHE.(AU)


Descreve-se um caso clínico no qual ocorreu mudança na cor da pele e do pelo após anestesia epidural sacrococcígea numa gata cruzada de raça Siamês de nove meses submetida à ovariohisterectomia (OVH). Seis semanas após a cirurgia, durante uma avaliação pós-operatória, notou-se que na região sacrococcígea, a cor da pele e o crescimento do pelo apresentavam uma cor escura, comparável à das extremidades do corpo (face, orelhas, membros e cauda). A pele e o crescimento do pelo do abdómen, que também havia sido tosquiado, apresentavam uma cor padrão. A enzima chave da via melanogênica em mamíferos é a tirosinase (TYR) e o fenótipo siamês sensível à temperatura é o resultado de mutações genéticas que tornam a função TYR termolábil. A atividade da TYR nestes gatos é limitada às extremidades onde a temperatura é mais baixa, enquanto a produção de pigmento é prejudicada em outras áreas do corpo. A tricotomia da região sacrococcígea realizada durante o inverno nesta gata com acesso livre ao ambiente externo, provavelmente determinou um aumento da atividade da TYR nesta área, promovendo a produção de pigmento. A ausência das mesmas alterações na região abdominal pode ser justificada pela menor exposição desta área do corpo ao ambiente externo, também devido aos hábitos felinos de sedentarismo, que evitam resfriamento significativo nestas regiões. Este relato destaca a importância de se levar em consideração a possibilidade deste tipo de ocorrência quando da realização de uma anestesia epidural nesta raça de gatos. Além disso, os autores recomendam uma abordagem abdominal na linha média ao invés de uma abordagem de flanco para realizar a OVH nesta raça, a fim de evitar a alteração da cor da pele.(AU)


Subject(s)
Animals , Cats , Cats , Clinical Laboratory Techniques , Anesthesia, Epidural/veterinary , Sacrococcygeal Region , Hair Removal
4.
Mar Pollut Bull ; 150: 110704, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31740180

ABSTRACT

Estuaries are very sensitive ecosystems to human activities and the natural evolution of their drainage basins located upstream. Pollution derived from human activities, such as historical mining or recent industrial wastes, can significantly affect their environmental quality. This paper analyzes the silver and copper contents of four cores extracted in two estuaries of SW Spain. Its chronology and vertical evolution allow to differentiate the effects of several pollution episodes (natural, Roman, 19th-20th centuries) on its different sedimentary environments in the last 6 million years. Possible future applications are included in the fields of environmental management or even education.


Subject(s)
Copper/analysis , Environmental Monitoring/methods , Geologic Sediments , Silver/analysis , Water Pollutants, Chemical/analysis , Water Pollution, Chemical/statistics & numerical data , Ecosystem , Estuaries , Humans , Spain
5.
Article in English | MEDLINE | ID: mdl-31067685

ABSTRACT

In the last few decades, the rapid technological evolution has led to a growing generation of waste electrical and electronic equipment (WEEE). Not rarely, it has been exported from industrialized to developing countries, where it represents a secondary source of valuable materials such as gold, copper, and silver. The recycling of WEEE is often carried out without any environmental and health protection. This paper reviews recent literature dealing with the informal treatment of WEEE in developing regions, gathering and analyzing data on concentration of both inorganic and organic pollutants in the environment. Open burning practices are revealed as most polluting 'technology', followed by mechanical treatment and leaching. Significant levels of pollutants have been detected in human bodies, both children and adults, working in or living in areas with informal WEEE treatment.


Subject(s)
Developing Countries , Electronic Waste , Environmental Pollution/analysis , Waste Management/methods , Humans
6.
Environ Sci Pollut Res Int ; 26(11): 11042-11052, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30793245

ABSTRACT

Waste electric and electronic equipment (WEEE) represents a potential secondary source of valuable materials, whose recovery is a growing business activity worldwide. In low-income countries, recycling is carried out under poorly controlled conditions resulting in severe environmental pollution. High concentrations of both metallic and organic pollutants have been confirmed in air, soil, water, and sediments in countries with informal recycling areas. The release of these contaminants into the environment presents a risk to the health of the exposed population that has been widely acknowledged but still needs to be quantified. The aim of this work was to evaluate the relative risk from inhalation associated with the open burning of different kinds of WEEE. The shrinking core model was applied to estimate the concentration of the metals which would be released into the environment during the incineration of different types of WEEE. In addition, the potential generation of dioxins during the same informal practice was estimated, based on the plastic content of the WEEE. The results provided for the first time a comparative analysis of the risk posed from the open burning of WEEE components, proposing a methodology to address the absolute risk assessment to workers from the informal recycling of WEEE.


Subject(s)
Air Pollutants/analysis , Electronic Waste/analysis , Incineration/methods , Inhalation Exposure/adverse effects , Inhalation Exposure/analysis , Recycling/methods , Dioxins/analysis , Humans , Metals/analysis , Plastics/analysis , Risk Assessment
7.
Chemosphere ; 223: 171-179, 2019 May.
Article in English | MEDLINE | ID: mdl-30776762

ABSTRACT

Old mine tailings from Northern and Central Portugal were studied in order to perform a radiological and chemical characterization. The evaluation of massic activity of natural radionuclides and concentrations in tailings of polymetallic and Ra/U mines was performed by gamma spectrometry and neutron activation analysis. Iron speciation was carried out by Mössbauer spectroscopy. In polymetallic tailings with physical ore processing (Cumieira and Verdes - exploited for Sn, Nb-Ta) higher contents of Th, 228Ra and 226Ra in the coarser materials occur, probably due to their presence in host rock and ore fragments. In finer tailings, washing may explain the lower 226Ra and 210Pb massic activity. In tailings with physical/chemical ore processing (Covas - exploited for W and Sn) high U contents and a tendency for higher 226Ra and 210Pb massic activity in the fine materials is observed, probably due to their incorporation in nano-sized particles of iron oxides. A high variation of the 210Pb/226Ra ratio occurs in polymetallic tailings; a deficit of 210Pb can be observed particularly in deposits of settling tanks drained from dumps of chemically treated ore. In Ervideira-Mestras tailings (Ra/U exploitation) where no ore process in situ was performed, a near equilibrium between 210Pb and 226Ra occurs. Dose risk assessment was carried out by calculating external outdoor Annual Effective Dose Rate; the dose rates in air due to terrestrial gamma radiation are low for the polymetallic tailings (<47 nGy/h), and higher for tailings of Ra/U (up to 4130 nGy/h), in the worst scenario.


Subject(s)
Mining , Radioisotopes/analysis , Soil Pollutants, Radioactive/analysis , Gamma Rays , Lead Radioisotopes/analysis , Portugal , Radium/analysis , Risk Assessment , Spectrometry, Gamma , Uranium/analysis
8.
Environ Sci Pollut Res Int ; 25(1): 683-692, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29058259

ABSTRACT

In developing countries, the recovery of valuable materials from Waste Electrical and Electronic Equipment (WEEE) is carried out via uncontrolled practices, posing potentially severe risks both to human health and the environment. The assessment of the risk, which depends on both the kind and hazardous properties of the substances contained in WEEE, is currently limited as the exposure scenario for the single informal practice cannot be fully characterized for this purpose. In this context, this work proposes and evaluates a strategy to identify the relative potential harm of different kinds of WEEE by their content in metals, selected as the target substances of concern. This was based on the individual metal content, primarily located in the printed circuit boards (PCBs) of the different devices. The metal composition of the individual PCBs was identified and the dominant unregulated metal recovery practices were reviewed to identify the most suitable parameter to express the toxicity of these metals. Based on a mass-normalized cumulative toxicity, via the inhalation route, individual components were assessed from compositional variation found in the literature. The results is a semiquantitative ranking of individual components, revealing significant differences in potential harm posed by different electronic appliances and an opportunity to provide prioritization strategies in future management.


Subject(s)
Air Pollutants/analysis , Electronic Waste/analysis , Hazardous Substances/analysis , Recycling/methods , Flame Retardants/analysis , Humans , Metals, Heavy/analysis , Risk Assessment
9.
Environ Sci Pollut Res Int ; 24(13): 11978-11990, 2017 May.
Article in English | MEDLINE | ID: mdl-26432271

ABSTRACT

Barks from Prosopis juliflora (acacia) were collected in 12 sites of different geological contexts over the volcanic Fogo Island (Cape Verde). Elemental contents of Ba, Br, Co, Cr, Fe, K, Na, Zn and some rare earth elements (REE)-La, Ce, Sm, Eu, Tb, Yb, and Lu, were obtained for biological samples and topsoils by using k 0-standardized and comparative method of instrumental neutron activation analysis (INAA), aiming the evaluation of chemical elements uptake by acacia bark. This first biomonitoring study of Fogo Island showed that, in general, significant accumulations of trace elements present in high amounts in these soils occur. This can be partially explained by the semi-arid climate with a consequent bioavailability of chemical elements when rain drops fall in this non-polluted environment. REE enrichment factors (EFs) increase with the decrease of ionic radius. Heavy REE (HREE) are significantly enriched in bark, which agrees with their release after the primary minerals breakdown and the formation of more soluble compounds than the other REE, and uptake by plants. Among the potential harmful chemical elements, Cr appears to be partially retained in nanoparticles of iron oxides. The high EFs found in tree barks of Fogo Island are certainly of geogenic origin rather than anthropogenic input since industry and the use of fertilizers is scarce.


Subject(s)
Acacia/chemistry , Air Pollutants/analysis , Environmental Monitoring/methods , Plant Bark/chemistry , Soil/chemistry , Cabo Verde , Islands
10.
Asian Pac J Cancer Prev ; 17(7): 3207-11, 2016.
Article in English | MEDLINE | ID: mdl-27509953

ABSTRACT

BACKGROUND: Skin cancer has a remarkable importance given the high incidence in the population. In Brazil, it is estimated that there were 98,420 new cases of nonmelanoma skin cancer among men and 83,710 new cases among women in 2014. OBJECTIVES: To verify signs and symptoms present in patients with skin neoplasms according to the literature and relate them to the nursing diagnoses of NANDA International. MATERIALS AND METHODS: Integrative literature review carried out from March to May 2015 in the databases: Cumulative Index to Nursing and Allied Health Literature, SCOPUS, National Library of Medicine and Nattional Institutes of Health, Latin American and Caribbean Sciences of Health and Web of Science. The descriptors used were: 'Signs and Symptoms' and 'Skin Neoplasms'. Sixteen articles were identified as the final sample. After review, the signs and symptoms of skin cancer identified in the literature were related to the defining characteristics present in NANDA International, with the aim to trace possible nursing diagnoses. RESULTS: The most prevalent signs and symptoms were: asymmetric and well circumscribed nodules with irregular borders; speckles with modified color aspect; ulcerations; blisters; pain; itching; and bleeding. The principal nursing diagnoses outlined were: risk for impaired skin integrity; impaired skin integrity; acute pain; risk of shock; and impaired comfort. CONCLUSIONS: The identification of signs and symptoms present in patients with skin cancer and the relationships of these with the nursing diagnoses of NANDA International provide a basis for qualified and systematized nursing care to this clientele.


Subject(s)
Nursing Diagnosis/methods , Skin Neoplasms/diagnosis , Skin Neoplasms/epidemiology , Brazil/epidemiology , Female , Humans , Male , Meta-Analysis as Topic , Physical Examination , Prevalence , Prognosis
11.
Hig. aliment ; 30(256/257): 18-25, maio/junho 2016.
Article in Portuguese | LILACS | ID: biblio-1332

ABSTRACT

Aminas bioativas vêm, ao longo dos anos, despertando o interesse dos pesquisadores no que se refere aos benefícios e aos prejuízos da sua presença ou mesmo do seu uso intencional, principalmente na alimentação de aves de corte, refletindo posteriormente na qualidade da carne produzida pelas mesmas. A presença de determinadas aminas em rações de aves de corte pode beneficiar e acelerar o desenvolvimento das mesmas, no entanto, quando presente em níveis elevados pode retardar o crescimento, causar disfunções metabólicas ou mesmo a morte dos animais. Estudos vêm sendo realizados a fim de definir quantidades ideais e tipos de aminas a ser adicionada à dieta a fim de propiciar um desenvolvimento adequado às aves sem, no entanto, apresentar resíduos na carne das mesmas.


Subject(s)
Animals , Poultry/growth & development , Biogenic Amines/analysis , Animal Feed/analysis , Poultry Products/analysis , Biogenic Amines/administration & dosage , Review Literature as Topic , Food Analysis
12.
J Appl Oral Sci ; 23(5): 497-507, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26537721

ABSTRACT

UNLABELLED: The value of aesthetic dentistry has precipitated several developments in the investigation of dental materials related to this field. The free marketing of these products is a problem and it is subject to various interpretations regarding its legality. There are several techniques for tooth whitening, the most used one being the external bleaching. It is the later version of such technique that poses the greatest danger of ingesting the product. The present study analysed the systemic effect of these products when they are swallowed. OBJECTIVE: This experimental study aimed to observe the effects of a tooth whitening product, whose active agent is 6% hydrogen peroxide, on the gastric mucosa of healthy and non-tumour gastric pathology animals. MATERIAL AND METHODS: Fifty Wistar-Han rats were used and then distributed into 5 groups, one for control and four test groups in which the bleaching product was administered in animals with and without non-tumour gastric pathology (induced by the administration of 1 sample of 50% ethanol and 5% of drinking water during 6 days) at different times of study by gavage. There was a decrease in body weight in animals of groups handled during the study period, which was most pronounced in IV and VA groups. Changes in spleen weight relative to body weight revealed no statistically significant changes. An analysis of the frequency was performed on the results of macroscopic observation of the gastric mucosa. RESULTS: The gastric mucosa revealed lesions in all manipulated groups, being more frequent in groups III and IV. It appears that there is a synergism when using hydrogen peroxide and 50% ethanol in the same group. CONCLUSION: Therefore, it seems that there are some signs of toxicity 3 to 4 days after administration of 6% hydrogen peroxide. The prescription of these therapies must be controlled by the clinician and the risks must be minimized.


Subject(s)
Gastric Mucosa/drug effects , Hydrogen Peroxide/toxicity , Tooth Bleaching Agents/toxicity , Tooth Bleaching/adverse effects , Animals , Body Weight , Ethanol/toxicity , Gastric Mucosa/pathology , Organ Size , Rats, Wistar , Spleen/drug effects , Spleen/pathology , Time Factors
13.
J. appl. oral sci ; 23(5): 497-507, Sept.-Oct. 2015. tab, graf
Article in English | LILACS, BBO - Dentistry | ID: lil-764156

ABSTRACT

The value of aesthetic dentistry has precipitated several developments in the investigation of dental materials related to this field. The free marketing of these products is a problem and it is subject to various interpretations regarding its legality. There are several techniques for tooth whitening, the most used one being the external bleaching. It is the later version of such technique that poses the greatest danger of ingesting the product. The present study analysed the systemic effect of these products when they are swallowed.Objective This experimental study aimed to observe the effects of a tooth whitening product, whose active agent is 6% hydrogen peroxide, on the gastric mucosa of healthy and non-tumour gastric pathology animals.Material and Methods Fifty Wistar-Han rats were used and then distributed into 5 groups, one for control and four test groups in which the bleaching product was administered in animals with and without non-tumour gastric pathology (induced by the administration of 1 sample of 50% ethanol and 5% of drinking water during 6 days) at different times of study by gavage. There was a decrease in body weight in animals of groups handled during the study period, which was most pronounced in IV and VA groups. Changes in spleen weight relative to body weight revealed no statistically significant changes. An analysis of the frequency was performed on the results of macroscopic observation of the gastric mucosa.Results The gastric mucosa revealed lesions in all manipulated groups, being more frequent in groups III and IV. It appears that there is a synergism when using hydrogen peroxide and 50% ethanol in the same group.Conclusion Therefore, it seems that there are some signs of toxicity 3 to 4 days after administration of 6% hydrogen peroxide. The prescription of these therapies must be controlled by the clinician and the risks must be minimized.


Subject(s)
Animals , Gastric Mucosa/drug effects , Hydrogen Peroxide/toxicity , Tooth Bleaching Agents/toxicity , Tooth Bleaching/adverse effects , Body Weight , Ethanol/toxicity , Gastric Mucosa/pathology , Organ Size , Rats, Wistar , Spleen/drug effects , Spleen/pathology , Time Factors
14.
Acta Med Port ; 20(1): 37-46, 2007.
Article in Portuguese | MEDLINE | ID: mdl-17624282

ABSTRACT

This study aimed at studying the influence of the quantitative variation of the autologous spongy bone graft on its osteogenic properties by virtue of the fact that its attainment has inconveniences of significant morbidity at local donor level and the limited quantity of grafting able to be obtained. Recourse was made to an osteotomy model for this purpose with the removal of a small 4 mm segment at the mid-diaphysis of the left tibia of twenty one sheep, stabilised by an osteosynthesis plate on which different quantities of autografting spongy bone were applied so that the referred bone defect (1) would not to be completely filled (1.5 g), (2) would be filled without any compression (3 g) and (3) would be filled with an excessive quantity (5 g) (n=5/each group). (4) A control osteotomy (n=6) was also carried out where the bone defect remained empty. Comparison of the evolution of bone regeneration during the postoperative period of 12 weeks was carried out by means of conventional radiographic exams and optical densitometry analysis and by radiological bone densitometry (DEXA--Dual-Energy X-ray Absorptiometry), bone histomorphometry and histological analysis after the animals' euthanasia. Optical density was significantly affected (p<0.0001) by the treatment and by time and with significant differences between the various groups under study over the same time of post-operative period: during immediate postoperative and on the 2nd (p <0.01), 4th (p <0.001), 6th and 8th weeks (p <0.05), but not on the 10th and 12th (p >0.05) post-operative weeks. Bone mineral density (BMD), obtained by DEXA, was 0.4347 +/- 0.3821 g/cm2 in the control group and 0.7482 +/- 0.2327 g/cm2, 0.9517 +/- 0.2292 g/cm2 e 1.0409 +/- 0.0681 g/cm2 in the groups that had received 1.5 g, 3g and 5 g of bone graft, respectively. The BV was 39.2 +/- 24.4% with the control group and 62.0 +/- 14.4%, 76.0 +/- 15.2% and 84.0+/-4.2% in the groups that had received 1.5 g, 3g and 5 g of bone graft, respectively. The BMD and BV were significantly affected (p<0.05 and p <0.01, respectively) by the treatment, nevertheless, there were no significant differences (p >0.05) between the groups that had received the largest volumes of autografting spongy bone on the 12th week of the post-operative period.The conclusion was reached that there was no advantage in excessively filling an osteotomy gap with autografting spongy bone and attainment of only the volume strictly required to fill the osteotomy gap at issue was needed.


Subject(s)
Bone Regeneration , Bone Transplantation , Osteotomy , Tibia/surgery , Animals , Sheep
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