Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 89
Filtrar
1.
Nature ; 583(7817): 560-566, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32699397

RESUMO

There are concerns that recent climate change is altering the frequency and magnitude of river floods in an unprecedented way1. Historical studies have identified flood-rich periods in the past half millennium in various regions of Europe2. However, because of the low temporal resolution of existing datasets and the relatively low number of series, it has remained unclear whether Europe is currently in a flood-rich period from a long-term perspective. Here we analyse how recent decades compare with the flood history of Europe, using a new database composed of more than 100 high-resolution (sub-annual) historical flood series based on documentary evidence covering all major regions of Europe. We show that the past three decades were among the most flood-rich periods in Europe in the past 500 years, and that this period differs from other flood-rich periods in terms of its extent, air temperatures and flood seasonality. We identified nine flood-rich periods and associated regions. Among the periods richest in floods are 1560-1580 (western and central Europe), 1760-1800 (most of Europe), 1840-1870 (western and southern Europe) and 1990-2016 (western and central Europe). In most parts of Europe, previous flood-rich periods occurred during cooler-than-usual phases, but the current flood-rich period has been much warmer. Flood seasonality is also more pronounced in the recent period. For example, during previous flood and interflood periods, 41 per cent and 42 per cent of central European floods occurred in summer, respectively, compared with 55 per cent of floods in the recent period. The exceptional nature of the present-day flood-rich period calls for process-based tools for flood-risk assessment that capture the physical mechanisms involved, and management strategies that can incorporate the recent changes in risk.

2.
Arthroscopy ; 39(3): 881-886, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36543662

RESUMO

PURPOSE: The objective of this systematic literature review was to investigate the effects of the clinical application of bone marrow aspirate (BMA) and/or bone marrow aspirate concentrate (BMAC) in tendon and cartilage injuries in the foot and ankle. METHODS: A search of the Embase, MEDLINE/PubMed, CINAHL, and Cochrane databases was performed in January 2021. The risk of bias of the studies was assessed using the tool "A Cochrane Risk of Bias Assessment Tool for Non-Randomized Studies." The outcomes analyzed included pain reduction and functional improvement with the use of BMA/BMAC in patients with tendon and cartilage injuries in the foot and ankle. RESULTS: Eleven studies met the inclusion criteria for analysis, involving a total of 527 subjects with osteochondral lesions (OCLs) of the talus, cartilage lesions of the talus, and acute Achilles tendon rupture. BMAC was applied alone in 4 studies, and in 7 studies, it was compared with other techniques such as matrix-induced autologous chondrocyte implantation, particulate juvenile articular cartilage, or microfracture. Interventions demonstrated improved function and reduced foot and ankle pain and showed no serious adverse effects. CONCLUSIONS: Evidence indicates that BMAC provides good clinical results, with improved function and reduced pain in adults with OCL and cartilage lesions of the talus and acute Achilles tendon rupture. LEVEL OF EVIDENCE: Level IV, systematic review of level II to IV studies.


Assuntos
Tendão do Calcâneo , Doenças das Cartilagens , Cartilagem Articular , Tálus , Humanos , Adulto , Medula Óssea , Tendão do Calcâneo/cirurgia , Tálus/cirurgia , Tálus/lesões , Cartilagem Articular/lesões , Doenças das Cartilagens/patologia , Dor , Ruptura/patologia , Resultado do Tratamento
3.
BMC Vet Res ; 16(1): 463, 2020 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-33246455

RESUMO

BACKGROUND: The knowledge of how owners view the body condition of their animals is an important factor for the success of the prevention/treatment of obesity and the engagement/adherence to nutritional interventions, which are fundamental to improve the animal prognosis. For this reason, the objective of this study was to evaluate the perception of the owners regarding the body condition score of their animals, compare the perception between cat vs. dog owners, and owners from the countryside vs. metropolitan region of São Paulo State in Brazil. RESULTS: 601 dogs and 110 cats were included in this study. There was no significant difference in body condition score assigned by owners by species. Owners of dogs and cats classified by the veterinarian as ideal, overweight, and obese who disagree with body condition score assigned by veterinarian mainly underestimate the body condition score of their animals, while lean dogs' owners overestimate it. Countryside dog owners had a higher rate of disagreement with the veterinarian and more often underestimate the body condition score than owners from the metropolitan region. The owners of lean cats have the same judgments with veterinarians. CONCLUSIONS: Owners of dogs and cats have difficulty assessing the body condition score, especially owners from countryside.


Assuntos
Composição Corporal , Doenças do Gato/prevenção & controle , Doenças do Cão/prevenção & controle , Obesidade/veterinária , Fenômenos Fisiológicos da Nutrição Animal , Animais , Brasil , Gatos , Cães , Feminino , Humanos , Masculino , Obesidade/prevenção & controle , Propriedade
4.
Skin Res Technol ; 25(4): 461-468, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30623998

RESUMO

BACKGROUND: Nipple pain is the second most common reason for early weaning, exceeded only by the insufficient milk supply. Nipple fissures can bring other problems, acting also as a portal for bacteria and leading to mastitis. This work proposes the breast protector composite development using materials with tissue repair and moisturizing properties, aligned with a low-cost procedure, aiming not only to relieve pain, but also to heal the nipple fissures caused by breastfeeding. MATERIALS AND METHODS: For the dressings, production was used Natural Latex extracted from the rubber tree and glycerol. The Samples were evaluated chemically and physically by the techniques of Scanning Electron Microscopy, Fourier transform infrared spectroscopy, mechanical traction, and contact angle. The samples were also biologically evaluated by the hemolytic and cytotoxic activity assays. RESULTS: From the physical-chemical assays, the matrix with glycerol has high pore density; the natural latex and glycerol do not covalently interact, indicating that the glycerol can be released; the glycerol addition makes the matrix more elastic but fragile, and increase the wettability. From the biological assays, both materials showed no hemolytic effects; and the cytotoxicity results showed that glycerol did not present cytotoxicity in the fibroblasts, but show a dose-dependent influence in the keratinocytes. CONCLUSION: The material developed for application in breast fissures has mechanical properties similar to those found for materials for dermal applications, present high wettability and pore density. Furthermore, the material showed no cytolytic activity and the tests with skin cell cultures demonstrated the biocompatibility.


Assuntos
Bandagens/tendências , Aleitamento Materno/efeitos adversos , Mamilos/patologia , Dor/prevenção & controle , Bandagens/normas , Materiais Biocompatíveis/química , Crioprotetores/administração & dosagem , Crioprotetores/química , Feminino , Glicerol/administração & dosagem , Glicerol/química , Humanos , Látex/química , Teste de Materiais/métodos , Microscopia Eletrônica de Varredura , Mamilos/efeitos dos fármacos , Pele/efeitos dos fármacos , Pele/patologia , Espectroscopia de Infravermelho com Transformada de Fourier , Cicatrização/efeitos dos fármacos
5.
Lasers Med Sci ; 34(1): 191-199, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30443882

RESUMO

Sepsis is a big health problem and one of the most common causes of acute lung injury (ALI) leading to high mortality. Pro-resolving mediators play an important role in abrogating the inflammation and promoting tissue homeostasis restoration. ALI treatment is still a clinical health problem, so new therapies are needed. Here, we evaluated the effect of photobiomodulation treatment on the resolution process of ALI induced by lipopolysaccharide (LPS). Male Balb/c mice were submitted to LPS (ip) or vehicle and irradiated or not with light emitting diode (LED) 2 and 6 h after LPS or vehicle injection, and the parameters were investigated 3 and 7 days after the injections. Our results showed that after 3 days of LED treatment the blood and bronchoalveolar lavage (BAL) cells as well as interleukins (IL) including IL-6 and IL-17 were reduced. No differences were observed in the bone marrow cells, tracheal reactivity, and lipoxin A4 and resolvin E2. Indeed, after 7 days of LED treatment the bone marrow cells, lymphocytes, and lipoxin A4 were increased, while IL-6, IL-17, and IL-10 were decreased. No differences were observed in the blood cells and tracheal reactivity. Thus, our results showed that LED treatment attenuated ALI induced by sepsis by modulating the cell mobilization from their reserve compartments. In addition, we also showed later effects of the LED up to 7 days after the treatment. This study proposes photobiomodulation as therapeutic adjuvant to treat ALI.


Assuntos
Lesão Pulmonar Aguda/etiologia , Lesão Pulmonar Aguda/radioterapia , Inflamação/radioterapia , Terapia com Luz de Baixa Intensidade , Sepse/complicações , Animais , Medula Óssea/patologia , Medula Óssea/efeitos da radiação , Lavagem Broncoalveolar , Movimento Celular/efeitos da radiação , Colinérgicos/farmacologia , Citocinas/metabolismo , Ácido Eicosapentaenoico/análogos & derivados , Ácido Eicosapentaenoico/metabolismo , Inflamação/patologia , Lipopolissacarídeos , Lipoxinas/metabolismo , Pulmão/patologia , Pulmão/efeitos da radiação , Masculino , Camundongos Endogâmicos BALB C , Contração Muscular/efeitos da radiação , Músculo Liso/fisiopatologia , Músculo Liso/efeitos da radiação
6.
Pediatr Nephrol ; 31(8): 1295-303, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-26913724

RESUMO

BACKGROUND: Enuresis (NE) is a clinical condition of multifactorial etiology that leads to difficulties in child/adolescent social interaction. METHODS: This was a prospective study on the impact of multidisciplinary assessment of 6- to 17-year-old patients with monosymptomatic nocturnal enuresis (MNE), including a structured history, clinical/neurological examination, bladder and bowel diaries, sleep diary and questionnaires, psychological evaluation [Child Behavior Checklist (CBCL) and PedsQL 4.0 questionnaires], urinary sonography, blood and urine laboratory tests, polysonography (PSG), and balance evaluation. RESULTS: A total of 140 enuretic participants were evaluated, of whom 27 were diagnosed with NE complicated by urinary disorder, four with hypercalciuria, three with nephropathy and one with attention-deficit hyperactivity disorder. Among the 87 participants who underwent PSG, six were diagnosed with severe apnea. Of the 82 MNE patients who underwent full assessment, 62 were male (75.6 %), and the mean age was 9.5 (±2.6) years. A family history of NE was diagnosed in 91.1 % of first- and second-degree relatives, constipation in 89.3 % and mild/moderate apnea in 40.7 %. Balance control alteration was identified by physical therapy evaluation of MNE patients. Participants' quality of life evaluation scores were significantly lower than those of their parents. CONCLUSION: Enuresis is a multifactorial disorder that requires a structured diagnostic approach.


Assuntos
Enurese Noturna/complicações , Enurese Noturna/diagnóstico , Adolescente , Criança , Feminino , Humanos , Masculino , Prontuários Médicos , Exame Neurológico , Polissonografia , Estudos Prospectivos , Inquéritos e Questionários
7.
Occup Environ Med ; 71(7): 459-65, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24652231

RESUMO

OBJECTIVE: To describe the survey methodology and initial general findings of the first Central American Survey of Working Conditions and Health. METHODS: A representative sample of 12,024 workers was interviewed at home in Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua and Panama. Questionnaire items addressed worker demographics, employment conditions, occupational risk factors and self-perceived health. RESULTS: Overall, self-employment (37%) is the most frequent type of employment, 8% of employees lack a work contract and 74% of the workforce is not covered by social security. These percentages are higher in Guatemala, Honduras and El Salvador, and lower in Costa Rica, Panama and Nicaragua. A third of the workforce works more than 48 h per week, regardless of gender; this is similar across countries. Women and men report frequent or usual exposures to high ambient temperature (16% and 25%, respectively), dangerous tools and machinery (10%, 24%), work on slippery surfaces (10%, 23%), breathing chemicals (12.1%, 18%), handling toxic substances (5%, 12.1%), heavy loads (6%, 20%) and repetitive movements (43%, 49%). Two-thirds of the workforce perceive their health as being good or very good, and slightly more than half reports having good mental health. CONCLUSIONS: The survey offers, for the first time, comparable data on the work and health status of workers in the formal and informal economy in the six Spanish-speaking Central American countries, based on representative national samples. This provides a benchmark for future monitoring of employment and working conditions across countries.


Assuntos
Países em Desenvolvimento , Emprego , Saúde , Exposição Ocupacional , Acidentes de Trabalho , Adulto , América Central , Contratos , Transtornos Traumáticos Cumulativos , Coleta de Dados , Feminino , Substâncias Perigosas , Temperatura Alta , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Previdência Social , Estresse Mecânico , Propriedades de Superfície , Inquéritos e Questionários , Carga de Trabalho
8.
J Insect Sci ; 14: 50, 2014 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-25373197

RESUMO

Species from the Solenopsis saevissima (Smith) (Hymenoptera: Formicidae) species group are native to South America and have a cosmopolitan distribution because they have been accidentally introduced in many countries around the world. In Brazil, they have a wide distribution, including urban areas. The present study was conducted to investigate the characterization of Solenopsis genus populations associated with urban/human interference sites in Brazil by analyzing the mitochondrial gene cytochrome oxidase I and estimating the degree of relatedness of these populations to make inferences about their phylogeny and also observe the patterns of mitochondrial haplotype (mitotype) distribution across their range. The results revealed complete geographical coherence and polyphyly for the Solenopsis invicta Buren and Solenopsis saevissima species groups, which confirms the diversity of the genera. It also suggests the possibility that reproductively-isolated populations occur, resulting in the evolutionary process of speciation. No predominant haplotype was found in the populations analyzed, but some were more prevalent.


Assuntos
Formigas/classificação , Formigas/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Proteínas de Insetos/genética , Proteínas Mitocondriais/genética , Filogenia , Animais , Formigas/metabolismo , Brasil , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Proteínas de Insetos/metabolismo , Proteínas Mitocondriais/metabolismo , Dados de Sequência Molecular , Análise de Sequência de DNA
9.
Sci Total Environ ; 916: 170268, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38246390

RESUMO

Beef production in pasture-based systems is increasingly contested due to related biophysical and environmental challenges. Addressing these requires rigorous science-based evidence to inform private decisions and public policies. Increasing yields and simultaneously reducing the negative environmental impacts of agricultural and livestock production are central to sustainable intensification approaches. Yet, stocking rate, the commonly used metric for animal productivity in pastures, or more broadly, of sustainable intensification in pastoral production systems, warrants scrutiny to signpost successful transformative change of food systems and to avoid provision of misleading policy advice. Here we discuss why future studies would benefit of considering the two constituent elements of productivity in pastoral systems - animal performance (kg of animal product/head) and stocking rates (heads/ha) -, rather than stocking rates alone.


Assuntos
Agricultura , Meio Ambiente , Bovinos , Animais , Gado , Política Pública
10.
Beilstein J Nanotechnol ; 15: 631-637, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38887528

RESUMO

In this study, we present a novel approach for the exfoliation of titanium nitride (TiN) powders utilizing a rapid, facile, and environmentally friendly non-thermal plasma method. This method involves the use of an electric arc and nitrogen as the ambient gas at room temperature to generate ionized particles. These ionized species interact with the ceramic crystal of TiN, resulting in a pronounced structural expansion. The exfoliated TiN products were comprehensively characterized using transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. Remarkably, the cubic crystal structure of TiN was effectively retained, while the (200) crystal plane d-spacing increased from 2.08 to 3.09 Å, accompanied by a reduction in crystallite size and alterations in Raman vibrational modes. Collectively, these findings provide compelling evidence for the successful exfoliation of TiN structures using our innovative non-thermal plasma method, opening up exciting possibilities for advanced material applications.

11.
Work ; 74(1): 219-226, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36214006

RESUMO

BACKGROUND: At energy distribution companies, office and operational employees work in different occupational environments. Cardiovascular diseases (CVD) can develop due to occupational factors and can often lead to morbidity and disability. OBJECTIVE: To evaluate the risk of CVD in workers with different occupations in an energy distribution company, using cardiometabolic indices. METHODS: Workers (men), aged between 20 and 70 years, were divided into two groups: operational (n = 78) and office (n = 106) workers. Their metabolic profiles were analyzed using anthropometric and laboratory data to obtain the atherogenic plasma index (AIP) and insulin resistance index (TyG), and to identify the hypertriglyceridemic waist (HTGW) phenotype as cardiometabolic indicators. RESULTS: There was no difference in CVD risk between the two groups. However, 82% of the test subjects presented a high risk for the development of atherosclerosis based on the AIP, and 11.4% presented the HTGW phenotype, along with the presence of dyslipidemia, insulin resistance, and being overweight as risk factors for CVD. CONCLUSIONS: Although the identified risk factors are not related to the type of occupation at work, companies in the electricity sector can invest in the implementation of measures for health promotion to protect and prevent diseases and improve labor productivity and quality.


Assuntos
Doenças Cardiovasculares , Cintura Hipertrigliceridêmica , Resistência à Insulina , Masculino , Humanos , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Brasil/epidemiologia , Fatores de Risco , Cintura Hipertrigliceridêmica/complicações
12.
Sci Data ; 10(1): 44, 2023 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-36658229

RESUMO

There is a growing need for past weather and climate data to support science and decision-making. This paper describes the compilation and construction of a global multivariable (air temperature, pressure, precipitation sum, number of precipitation days) monthly instrumental climate database that encompasses a substantial body of the known early instrumental time series. The dataset contains series compiled from existing databases that start before 1890 (though continuing to the present) as well as a large amount of newly rescued data. All series underwent a quality control procedure and subdaily series were processed to monthly mean values. An inventory was compiled, and the collection was deduplicated based on coordinates and mutual correlations. The data are provided in a common format accompanied by the inventory. The collection totals 12452 meteorological records in 118 countries. The data can be used for climate reconstructions and analyses. It is the most comprehensive global monthly climate dataset for the preindustrial period so far.

13.
Sci Data ; 10(1): 402, 2023 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-37353567

RESUMO

Documentary climate data describe evidence of past climate arising from predominantly written historical documents such as diaries, chronicles, newspapers, or logbooks. Over the past decades, historians and climatologists have generated numerous document-based time series of local and regional climates. However, a global dataset of documentary climate time series has never been compiled, and documentary data are rarely used in large-scale climate reconstructions. Here, we present the first global multi-variable collection of documentary climate records. The dataset DOCU-CLIM comprises 621 time series (both published and hitherto unpublished) providing information on historical variations in temperature, precipitation, and wind regime. The series are evaluated by formulating proxy forward models (i.e., predicting the documentary observations from climate fields) in an overlapping period. Results show strong correlations, particularly for the temperature-sensitive series. Correlations are somewhat lower for precipitation-sensitive series. Overall, we ascribe considerable potential to documentary records as climate data, especially in regions and seasons not well represented by early instrumental data and palaeoclimate proxies.

14.
Int J Biol Macromol ; 249: 126016, 2023 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-37516224

RESUMO

Films and coatings manufactured with bio-based renewable materials, such as biopolymers and essential oils, could be a sustainable and eco-friendly alternative for protecting and preserving agricultural products. In this work, we developed films and coatings from pectin and chitosan to protect strawberries (Fragaria x ananassa Duch.) from spoilage and microbial contamination. We developed three coatings containing equal amounts of glycerol and Sicilian lemon essential oil (LEO) nanoemulsion. We identified seventeen chemicals from LEO by GC-MS chromatogram, including d-limonene, α-Pinene, ß-Pinene, and γ-Terpinene. The pectin and chitosan coatings were further characterized using different physicochemical, mechanical, and biological methods. The films demonstrated satisfactory results in strength and elongation at the perforation as fruit packaging. In addition, the coatings did not influence the weight and firmness of the strawberry pulps. We observed that 100 % essential oil was released in 1440 min resulting from the erosion process. Also, the oil preserved the chemical stability of the films. Antioxidant activity (AA), measured by Electron Paramagnetic Resonance (EPR), showed that the coatings loaded with 2 % LEO nanoemulsion (PC + oil) showed that almost 50 % of AA from LEO nanoemulsion was preserved. The chitosan and the pectin-chitosan coatings (PC + oil) inhibited filamentous fungi and yeast contaminations in strawberries for at least 14 days, showing a relationship between the AA and antimicrobial results.


Assuntos
Quitosana , Fragaria , Óleos Voláteis , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Fragaria/microbiologia , Quitosana/química , Pectinas/farmacologia , Pectinas/química , Antioxidantes/farmacologia , Antioxidantes/química , Conservação de Alimentos/métodos
15.
J Invertebr Pathol ; 109(3): 287-96, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22266203

RESUMO

Wolbachia are intracellular bacteria that commonly infect arthropods. Its prevalence among ants of the genus Solenopsis is high. In the present study, the presence and distribution of these endosymbionts was examined among populations of Solenopsis spp. from Brazil. A phylogenetic analysis based on the wsp gene was conducted to infer the evolutionary history of Wolbachia infections within the populations surveyed. A high frequency of Wolbachia bacteria was observed among the genus Solenopsis, 51% of the colonies examined were infected. Incidence was higher in populations from southern Brazil. However, little genetic variability was found among different Wolbachia strains within supergroups A and B. Our findings also suggest that horizontal transmission events can occur through the social parasite S. daguerrei.


Assuntos
Formigas/microbiologia , Evolução Biológica , Infecções por Bactérias Gram-Negativas/epidemiologia , Infecções por Bactérias Gram-Negativas/genética , Wolbachia/classificação , Wolbachia/genética , Sequência de Aminoácidos , Animais , Proteínas da Membrana Bacteriana Externa/genética , Brasil , Transmissão de Doença Infecciosa , Genes de Insetos/genética , Infecções por Bactérias Gram-Negativas/transmissão , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa
16.
Injury ; 53(7): 2389-2394, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35644641

RESUMO

Significant work has been done in recent years on treatment strategies for distal femur fractures. Inclusive reviews on periprosthetic fractures of distal femur have been carried out recently, but there is a lack of such reviews on the subject of native distal femur fractures in the recent literature. In this narrative review, we are set out to address the latest updates on geriatric non-periprosthetic distal femur fractures, and perform a rapid review over different treatment options, arriving at a summarized proposed treatment algorithm.


Assuntos
Fraturas do Fêmur , Fraturas Periprotéticas , Idoso , Placas Ósseas , Fraturas do Fêmur/cirurgia , Fêmur , Fixação Interna de Fraturas , Humanos , Fraturas Periprotéticas/cirurgia
17.
Front Bioeng Biotechnol ; 10: 794460, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35519607

RESUMO

Environmental contamination caused by inorganic compounds is a major problem affecting soils and surface water. Most remediation techniques are costly and generally lead to incomplete removal and production of secondary waste. Nanotechnology, in this scenario with the zero-valent iron nanoparticle, represents a new generation of environmental remediation technologies. It is non-toxic, abundant, cheap, easy to produce, and its production process is simple. However, in order to decrease the aggregation tendency, the zero-iron nanoparticle is frequently coated with chemical surfactants synthesized from petrochemical sources, which are persistent or partially biodegradable. Biosurfactants (rhamnolipids), extracellular compounds produced by microorganisms from hydrophilic and hydrophobic substrates can replace synthetic surfactants. This study investigated the efficiency of a rhamnolipid biosurfactant on the aggregation of nanoscale zer-valent iron (nZVI) and its efficiency in reducing nitrate in simulated groundwater at pH 4.0. Two methods were tested: 1) adding the rhamnolipid during chemical synthesis and 2) adding the rhamnolipid after chemical synthesis of nZVI. Scanning electron microscopy field emission, X-ray diffractometry, Fourier transform infrared spectroscopy, thermogravimetric analysis, Dynamic Light Scattering, and zeta potential measurements were used to characterize bare nZVI and rhamnolipid-coated nZVI. The effects of the type of nZVI and initial NO3 concentration were examined. Nanoscale zer-valent iron with the addition of the rhamnolipid after synthesis achieved the best removal rate of nitrate (about 78%), with an initial nitrate concentration of 25 mg L-1. The results suggest that nZVI functionalized with rhamnolipids is a promising strategy for the in situ remediations of groundwater contaminated by NO3, heavy metal, and inorganic carbon.

18.
PLoS One ; 17(1): e0261946, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35020762

RESUMO

Obesity is the most common nutritional disorder in dogs and it is associated with many comorbidities. Some obesity risk factors have already been established, however, the evaluation of the effect of different individual variables on weight loss induced by calorie restriction, although very important, is still poorly explored. The weight loss protocol can be updated and improved by more precise and adjusted equations throughout the weight loss program in the clinical routine practice. Therefore, the objective of this study was to analyze weight loss program dynamics in groups according to reproductive status, age, body size, and breed, as well as to define more accurately the amount of calories per target metabolic weight throughout the program. Data of 1,053 cases, presented between 2012 and 2019 at the Veterinary Hospital of the School of Veterinary Medicine and Animal Science of the University of São Paulo (FMVZ-USP) were retrospectively analyzed. A total of 77 obese dogs (body condition scores 8/9 or 9/9) of different ages, breeds, sizes, and reproductive status were selected. These dogs did not have any concomitant illnesses and successfully completed the weight loss program. Statistical analysis was performed and values of p≤0.05 were considered significant. The proposed weight loss program was based on an energy restriction protocol where daily energy intake (in kcal) was estimated as 70 kcal × target weight0.75. The target weight (TW) was defined as 80% of the animal's current weight. The average calorie intake for weight loss (calories x target weight0.75) was lower for spayed females (62.36), differing from intact males (66.14) and neutered males (65.41), while intact females (63.66) showed intermediate values without differing between groups (p = 0.015). There were no differences between weight loss calories according to age (p = 0.473) or body size (p = 0.084), allowing the use of the same mathematical equation for intact and neutered dogs; for dogs older than 1 year and of different body sizes. Regarding the breed, the average calorie intake was lower (p = 0.002) in mixed breed dogs (61.54xTW0.75) when compared to obesity-prone purebred dogs (64.17xTW0.75) and other purebreds (65.27xTW0.75). It was concluded that spayed females and mixed breed dogs have greater difficulty in losing weight, that is, they need fewer calories per metabolic body weight for the weight loss program to succeed. A more accurate equation for energy requirement for weight loss can improve chances of success, therefore improving compliance and helping clinical management of obesity in dogs.


Assuntos
Dieta Redutora , Doenças do Cão , Ingestão de Energia , Obesidade , Redução de Peso , Animais , Doenças do Cão/dietoterapia , Doenças do Cão/fisiopatologia , Cães , Feminino , Masculino , Obesidade/dietoterapia , Obesidade/fisiopatologia
20.
Colloids Surf B Biointerfaces ; 205: 111883, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34102528

RESUMO

Rhamnolipids are glycolipid biosurfactants that have remarkable physicochemical characteristics, such as the capacity for self-assembly, which makes these biomolecules a promising option for application in nanobiotechnology. Rhamnolipids produced from a low-cost carbon source (glycerol) were used to stabilize silver nanoparticles. Silver nanoparticles (AgNPs) have been the subject of studies due to their physical chemical as well as biological properties, which corroborate their catalytic and antimicrobial activity. We compared nanoparticles obtained with three different pH values during synthesis (5, 7 and 9) in the presence of rhamnolipids. Dynamic light scattering showed that larger particles were formed at pH 5 (78-190 nm) compared to pH 7 (6.5-43 nm) and 9 (5.6-28.1 nm). Moreover, nanoparticle stability (analyzed based on the zeta potential) was enhanced with the increase in pH from 5 to 9 (-29.86 ± 1.04, -37.83 ± 0.90 and -40.33 ± 0.57 mV, respectively). Field emission gun scanning electron microscopy confirmed the round morphology of the silver nanoparticles. The LSPR spectra of AgNP for the pHs studied are conserved. In conclusion, different pH values in the presence of rhamnolipids used in the synthesis of silver nanoparticles directly affect nanoparticle size and stability.


Assuntos
Nanopartículas Metálicas , Prata , Microscopia Eletrônica de Varredura
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA