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1.
J Endocrinol Invest ; 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38372939

RESUMO

BACKGROUND: Despite the increasing interest in transgender health research, to date little is known about the size of the transgender and gender diverse (TGD) population. METHODS: A web-based questionnaire survey was developed, including a collection of socio-demographic characteristics and disseminated online through social media. Gender incongruence was evaluated by using a 2-item approach assessing gender recorded at birth and gender identity. The primary objective of the present population-based study was to estimate the proportion of TGD people across ages among a large sample of people who answered a web-based survey. The secondary endpoints were to identify gender-affirming needs and possible barriers to healthcare access. RESULTS: A total of 19,572 individuals participated in the survey, of whom 7.7% reported a gender identity different from the sex recorded at birth. A significantly higher proportion of TGD people was observed in the youngest group of participants compared with older ones. Among TGD people who participated in the study, 58.4% were nonbinary, and 49.1% experienced discrimination in accessing health care services. Nonbinary TGD participants reported both the need for legal name and gender change, along with hormonal and surgical interventions less frequently compared to binary persons. CONCLUSIONS: Being TGD is not a marginal condition In Italy. A large proportion of TGD persons may not need medical and surgical treatments. TGD people often experience barriers to healthcare access relating to gender identity.

2.
J Endocrinol Invest ; 46(4): 779-786, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36348253

RESUMO

PURPOSE: The aim of our study was to assess dermatological changes in transgender people after the start of gender-affirming hormonal treatment (GAHT) and to investigate whether various hormonal preparations differently affect dermatological changes in trans AFAB (assigned female at birth) people. METHODS: In a multicenter prospective study, 484 participants (193 assigned male at birth/AMAB and 291 AFAB) were evaluated at baseline (T0), 6 (T1) and 12 months (T2) after the start of GAHT. Hair growth was assessed by the Ferriman-Gallwey (FG) score, acne by the Global Acne Grading Scale (GAGS), and alopecia by the Norwood Hamilton (NH) score. RESULTS: In AFAB people, a significant increase in FG score and NH grade was observed across time, as well as in GAGS score in a subsample of 71 individuals (p < 0.001). Testosterone (T) undecanoate and esters showed a higher increase in hair distribution at T2 vs. T1 as compared to T gel (p < 0.01). T esters showed a significantly higher impact in GAGS score modifications at T1 and at T2 vs. T0 compared to T gel (p = 0.021 and p = 0.003, respectively). In trans AMAB people, a significant decrease of FG score was observed across time (p < 0.001), although 51.3% of individuals still reported an FG score higher than eight after 12 months. CONCLUSION: T treatment increased hair growth, acne and alopecia prevalence in AFAB people, with T undecanoate and esters influencing hair growth more than T gel. Opposite dermatological changes were observed in AMAB people.


Assuntos
Acne Vulgar , Pessoas Transgênero , Transexualidade , Recém-Nascido , Humanos , Masculino , Feminino , Estudos Prospectivos , Alopecia/tratamento farmacológico , Alopecia/epidemiologia , Acne Vulgar/tratamento farmacológico
3.
Water Res ; 221: 118727, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35797818

RESUMO

Hypersaline endorheic aquatic systems (H-SEAS) are lakes/shallow playas in arid and semiarid regions that undergo extreme oscillations in salinity and severe drought episodes. Although their geochemical uniqueness and microbiome have been deeply studied, very little is known about the availability and quality of dissolved organic matter (DOM) in the water column.. A H-SEAS from the Monegros Desert (Zaragoza, NE Spain) was studied during a hydrological wetting-drying-rewetting cycle. DOM analysis included: (i) a dissolved organic carbon (DOC) mass balance; (ii) spectroscopy (absorbance and fluorescence) and (iii) a molecular characterization with Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). The studied system stored a large amount of DOC and under the highest salinity conditions, salt-saturated waters (i.e., brines with salinity > 30%) accumulated a disproportionate quantity of DOC, indicating a significant in-situ net DOM production. Simultaneously, during the hydrological transition from wet to dry, the DOM pool showed strong alterations of it molecular composition. Spectroscopic methods indicated that aromatic and degraded DOM was rapidly replaced by fresher, relatively small, microbial-derived moieties with a large C/N ratio. FT-ICR-MS highlighted the accumulation of small, saturated and oxidized molecules (molecular O/C > 0.5), with a remarkable increase in the relative contribution of highly oxygenated (molecular O/C>0.9) compounds and a decrease of aliphatic and carboxyl-rich alicyclic moleculesThese results indicated that H-SEAS are extremely active in accumulating and processing DOM, with the notable release of organic solutes probably originated from decaying microplankton under large osmotic stress at extremely high salinities.


Assuntos
Matéria Orgânica Dissolvida , Lagos , Hidrologia , Lagos/química , Espectrometria de Massas , Água
4.
J Endocrinol Invest ; 45(11): 2059-2068, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35779204

RESUMO

PURPOSE: We evaluated differences in Autism Spectrum Quotient (AQ) scores between a sample of hormone-naïve transgender and cisgender people and the impact of gender-affirming hormonal treatment (GAHT) on AQ scores across time. Furthermore, we assessed alexithymia and social anxiety as possible mediators of changes in AQ scores. METHODS: A cross-sectional comparison between cisgender and transgender people before GAHT and a prospective study on the effects of GAHT over time were performed. Transgender and cisgender people completed several psychometric tests. A total sample of 789 persons (n = 229 cismen; n = 172 ciswomen; n = 206 transmen; n = 182 transwomen) referring to the Florence and Rome Gender Clinics between 2018 and 2020 was enrolled. Of these, 62 participants referring to the Florence Gender Clinic were evaluated in a prospective study at baseline and 12 months after GAHT. RESULTS: Groups showed significant differences in terms of autistic traits: ciswomen showed lower scores of AQ, while cismen reported higher scores of AQ than all other groups. Transgender individuals showed significant higher levels of Gender Dysphoria (GD), body uneasiness, alexithymia and social anxiety, compared to cisgender ones. No significant differences in general psychopathology were found between groups. Across time, transmen and transwomen showed a significant reduction in AQ scores. The decrease in alexithymia and social anxiety after GAHT did not predict the change in AQ scores. CONCLUSIONS: The autistic traits in our sample may represent an epiphenomenon of GD rather than being part of an Autism Spectrum Disorder (ASD) condition, since they significantly decreased after 12 months of GAHT.


Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Pessoas Transgênero , Transtorno do Espectro Autista/tratamento farmacológico , Transtorno do Espectro Autista/epidemiologia , Transtorno Autístico/tratamento farmacológico , Transtorno Autístico/epidemiologia , Estudos Transversais , Hormônios , Humanos , Estudos Prospectivos
5.
Bioresour Technol ; 342: 126013, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34587581

RESUMO

In this work, a novel delignification process was proposed for the fractionation of invasive species such as Acacia dealbata wood. Organosolv process catalyzed with an acidic ionic liquid, 1-butyl-3-methylimidazolium hydrosulfate was evaluated to obtain cellulose-enriched solids and liquid fractions rich in hemicelluloses derived compounds and lignin. Under selected operating conditions (190 °C, 60% ethanol, 60 min of reaction time and 0.6 g 1-butyl-3-methylimidazolium hydrosulfate/g wood), high solubilization of lignin and hemicelluloses and cellulose recovery (87.5%, 88.7% and 88.3%, respectively), with a pulp yield of 43.1% were achieved. Moreover, 62.6 % of lignin was recovered by precipitation from the black liquor (composed mainly by 4.43 g xylose/L, 7.66 g furfural/L and 3.59 g acetic acid/L). In addition, enzymatic digestibility of delignified wood was also assayed. Overall, this work presents an alternative biorefinery scheme based in the use of environmentally friendly solvent and catalyst for selective fractionation of A. dealbata wood.


Assuntos
Acacia , Líquidos Iônicos , Catálise , Hidrólise , Lignina , Madeira
6.
Educ Prim Care ; 31(6): 365-370, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32862789

RESUMO

Purpose: Nowadays chronicity is one of the most frequent aspects of care doctors have to deal with. Students need to know and learn clinical, relational, social and managerial elements of chronicity and changes that disease causes in patients, families and doctors themselves. Methods: Students are supervised by a family doctor, in taking care of 'their' patient and of his/her family. They are asked to keep an updated diary, participate in the periodical revision of the medical history and write an end-report. Two focus groups were conducted, adopting a constructive qualitative approach in order to analyse results. Results: The focus groups and the SWOT analysis show common themes such as innovative learning and multidisciplinary approach. Clinical evolution of the disease, mental and body changes and the diagnostic and therapeutic future planning were also revealed. Conclusions: The main goal of this innovation was understanding the importance of a continuous clinical relationship and of the role of the doctor as 'therapy itself'. The project was demonstrated to be able to teach the future physicians how to practice more empathetic medicine and to improve the skills needed in a complex relational environment including that of chronic disease.


Assuntos
Doença Crônica , Continuidade da Assistência ao Paciente , Educação de Graduação em Medicina/métodos , Medicina de Família e Comunidade/educação , Medicina de Família e Comunidade/métodos , Grupos Focais , Humanos , Itália , Aprendizagem , Estudantes de Medicina/psicologia
7.
Sci Total Environ ; 714: 136838, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-32018979

RESUMO

Microbiota inhabiting the intermittent streambeds mediates several in-stream processes that are essential for ecosystem function. Reduced stream discharge caused by the strengthened intermittency and increased duration of the dry phase is a spreading global response to changes in climate. Here, the impacts of a 5-month desiccation, one-week rewetting and punctual storms, which interrupted the dry period, were examined. The genomic composition of total (DNA) and active (RNA) diversity, and the community level physiological profiles (CLPP) were considered as proxies for functional diversity to describe both prokaryotes and eukaryotes inhabiting the surface and hyporheic streambeds. Comparisons between the genomic and potential functional responses helped to understand how and whether the microbial diversity was sensitive to the environmental conditions and resource acquisition, such as water stress and extracellular enzyme activities, respectively. RNA expression showed the strongest relationship with the environmental conditions and resource acquisition, being more responsive to changing conditions compared to DNA diversity, especially in the case of prokaryotes. The DNA results presumably reflected the legacy of the treatments because inactive, dormant, or dead cells were included, suggesting a slow microbial biomass turnover or responses of the microbial communities to changes mainly through physiological acclimation. On the other hand, microbial functional diversity was largely explained by resources acquisition, such as metrics of extracellular enzymes, and appeared vulnerable to the hydrological changes and duration of desiccation. The data highlight the need to improve the functional assessment of stream ecosystems with the application of complementary metrics to better describe the streambed microbial dynamics under dry-rewet stress.


Assuntos
Microbiota , Biomassa , Hidrologia , Rios
8.
Sci Rep ; 9(1): 13506, 2019 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-31534180

RESUMO

Stream microbes that occur in the Mediterranean Basin have been shown to possess heightened sensitivity to intensified water stress attributed to climate change. Here, we investigate the effects of long-term drought (150 days), storms and rewetting (7 days) on the diversity and composition of archaea, bacteria and fungi inhabiting intermittent streambed sediment (surface and hyporheic) and buried leaves. Hydrological alterations modified the archaeal community composition more than the bacterial community composition, whereas fungi were the least affected. Throughout the experiment, archaeal communities colonizing sediments showed greater phylogenetic distances compared to those of bacteria and fungi, suggesting considerable adaptation to severe hydrological disturbances. The increase in the class abundances, such as those of Thermoplasmata within archaea and of Actinobacteria and Bacilli within bacteria, revealed signs of transitioning to a drought-favoured and soil-like community composition. Strikingly, we found that in comparison to the drying phase, water return (as sporadic storms and rewetting) led to larger shifts in the surface microbial community composition and diversity. In addition, microhabitat characteristics, such as the greater capacity of the hyporheic zone to maintain/conserve moisture, tended to modulate the ability of certain microbes (e.g., bacteria) to cope with severe hydrological disturbances.


Assuntos
Hidrologia/métodos , Microbiota/fisiologia , Adaptação Biológica/genética , Archaea/classificação , Bactérias/classificação , Mudança Climática , Secas , Fungos/classificação , Sedimentos Geológicos/microbiologia , Filogenia , Rios/microbiologia
9.
Cancer Microenviron ; 12(2-3): 67-76, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31297730

RESUMO

Epithelial mesenchymal crosstalk (EMC) describes the interaction of the tumor stroma and associated fibroblasts with epithelial cancer cells. In this study we analysed the effects of EMC on head and neck cancer cells. In tumor cell lines EMC was induced using media conditioned from a mix-culture of cancer cells and fibroblasts. Cell proliferation and chemotherapy response were assessed using direct cell counting. Flow cytometry, immunohistochemistry of markers of epithelial-mesenchymal transition (EMT) and subsequent TissueFaxs™ acquisition and quantification and western blot analysis were performed. Holotomographic microscopy imaging was used to visualize the effects of EMC on Cisplatin response of SCC-25 cells. EMC induced a hybrid epithelial-mesenchymal phenotype in SCC-25 cells with co-expression of vimentin and cytokeratin. This hybrid phenotype was associated with chemotherapy resistance and increased proliferation of the cells. The EMC conditioned medium led to an activation of the IL-6/STAT3 pathway with subsequent phosphorylation of STAT3. EMC induced a hybrid epithelial-mesenchymal phenotype in HNSCC cells accompanied by increased therapy resistance and cell proliferation. The IL-6/STAT3 pathway might be one of the major pathways involved in these EMC-related effects.

10.
Animal ; 13(12): 2847-2856, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31182175

RESUMO

(-)-Epigallocatechin-3-gallate (EGCG), the major phenolic compound of green tea, and hydroxytyrosol (HTyr), a phenol found in olive oil, have received attention due to their wide-ranging health benefits. To date, there are no studies that report their effect in bovine mammary gland. Therefore, the aim of this study was to evaluate the anti-oxidative and anti-inflammatory effects of EGCG and HTyr in bovine mammary epithelial cell line (BME-UV1) and to compare their antioxidant and anti-inflammatory in vitro efficacy. Sample of EGCG was obtained from a commercially available green tea extract while pure HTyr was synthetized in our laboratories. The mammary oxidative stress and inflammatory responses were assessed by measuring the oxidative stress biomarkers and the gene expression of inflammatory cytokines. To evaluate the cellular antioxidant response, glutathione (GSH/GSSH), γ-glutamylcysteine ligase activity, reactive oxygen species and malondialdehyde (MDA) production were measured after 48-h incubation of 50 µM EGCG or 50 µM of HTyr. Reactive oxygen species production after 3 h of hydrogen peroxide (50 µM H2O2) or lipopolysaccharide (20 µM LPS) exposure was quantified to evaluate and to compare the potential protection of EGCG and HTyr against H2O2-induced oxidative stress and LPS-induced inflammation. The anti-inflammatory activity of EGCG and HTyr was investigated by the evaluation of pro and anti-inflammatory interleukins (tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6 and IL-10) messenger RNA abundance after treatment of cells for 3 h with 20 µM of LPS. Data were analyzed by one-way ANOVA. (-)-Epigallocatechin-3-gallate or HTyr treatments induced higher concentrations of intracellular GSH compared to control cells, matched by an increase of γ-glutamylcysteine ligase activity mainly in cells treated with HTyr. Interestingly, EGCG and HTyr prevented oxidative lipid damage in the BME-UV1 cells by a reduction of intracellular MDA levels. (-)-Epigallocatechin-3-gallate and HTyr were able to enhance cell resistance against H2O2-induced oxidative stress. It was found that EGCG and HTyr elicited a reduction of the three inflammatory cytokines TNF-α, IL-1ß, IL-6 and an increase of the anti-inflammatory cytokine IL-10. Hydroxytyrosol has proved to be a strong antioxidant compound, and EGCG has shown mainly an anti-inflammatory profile. These results indicated that EGCG and HTyr may provide dual protection because they were able to attenuate oxidative stress and inflammatory responses, suggesting that these phenolic compounds are potential natural alternatives to be used in dairy cattle as feed supplement for reducing the development of oxidative and inflammatory processes related to parturition or as topical treatments for the control of bovine intramammary inflammation.


Assuntos
Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Catequina/análogos & derivados , Álcool Feniletílico/análogos & derivados , Animais , Catequina/farmacologia , Bovinos , Linhagem Celular , Células Epiteliais , Álcool Feniletílico/farmacologia
11.
Spectrochim Acta A Mol Biomol Spectrosc ; 214: 522-530, 2019 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-30818151

RESUMO

This paper reports for the first time a detailed spectroscopic investigation into the ground- and excited-state properties of α-amino-orcein (α-AO), one of the main components of the orcein dye, in solvents of different proticity and water at different pHs. In order to gain insight into the nature of the involved transitions and excited state deactivation pathways, the study was carried out by means of UV-Visible steady state and ultrafast spectroscopic techniques with the support of quantum mechanical calculations (DFT and TDDFT). The results highlight that the photophysical and photodynamic behaviour of α-AO are highly sensitive to the solvent proticity and pH. In particular, protic environment induces a red shift (55 nm) of the absorption spectrum together with a relevant decrease of the fluorescence quantum yield (from 0.19 in acetonitrile to 6.6 × 10-3 in methanol) and radiative rate constant (two orders of magnitude). A notable red shift is also caused by increasing the pH leading the molecule from monocationic to neutral and then monoanionic form through two deprotonation steps (pKa = 3.539 ±â€¯0.006 and 11.180 ±â€¯0.006). Following deprotonation, the molecule assumes spectral and photophysical properties very similar to those retrieved in protic media. The observed behaviour has been rationalized through the occurrence of hydrogen bonding, likely involving to a greater extent the carbonyl oxygen of α-AO and the protic solvent, that favours the charge delocalization on the whole chromophore as well as fast non-radiative excited state deactivation. The ultrafast spectroscopic investigation revealed in fact the presence, in protic solvent, of a short living component (tens of picoseconds), assignable to solvent complexed S1 state, alongside the long living component (few nanoseconds) observed in aprotic media and attributed to the solvent free S1 state. The results achieved in this study for α-AO provides an important contribution to the interpretation of absorption and fluorescence features of orcein dye mixture in more complex systems (protein based substrates within the many aspects of the cultural heritage and biomedical field) where hydrogen bonds are expected to play a crucial role in mediating the interaction with the environment.

12.
Sci Total Environ ; 669: 559-569, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30889445

RESUMO

Bioclogging is a main concern in infiltration systems as it may significantly shorten the service life of these low-technology water treatment methods. In porous media, biofilms grow to clog partially or totally the pore network. Dynamics of biofilm accumulation (e.g., by attachment, detachment, advective transport in depth) and their impact on both surface and deep bioclogging are still not yet fully understood. To address this concern, a 104 day-long outdoor infiltration experiment in sand tanks was performed, using secondary treated wastewater and two grain size distributions (GSDs): a monolayer system filled with fine sand, and a bilayer one composed by a layer of coarse sand placed on top of a layer of fine sand. Biofilm dynamics as a function of GSD and depth were studied through cross-correlations and multivariate statistical analyses using different parameters from biofilm biomass and activity indices, plus hydraulic parameters measured at different depths. Bioclogging (both surface and deep) was found more significant in the monolayer fine system than in the bilayer coarse-fine one, possibly due to an early low-cohesive biofilm formation in the former, driven by lower porosity and lower fluxes; under such conditions biomass is favorably detached from the top layer, transported and accumulated in depth, so that new biomass might colonize the surface. On the other hand, in the bilayer system, fluxes are highest, and the biofilm is still in a growing phase, with low biofilm detachment capability from the top sand layer and high microbial activity in depth, resulting in low bioclogging. Overall, the bilayer coarse-fine system allows infiltrating higher volume of water per unit of surface area than the monolayer fine one, minimizing surface and deep bioclogging, and thus increasing the longevity and efficiency of infiltration systems.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Biofilmes , Biomassa , Permeabilidade , Porosidade , Dióxido de Silício , Águas Residuárias , Movimentos da Água , Purificação da Água
14.
J Breath Res ; 12(4): 046004, 2018 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-29984708

RESUMO

A reliable method for the determination of carbonyl compounds in exhaled breath based on on-sorbent derivatization coupled with thermal desorption and gas chromatography-tandem mass spectrometry is described. The analytical performances were optimized for a mixture of C2-C9 aldehydes and C3-C9 ketones, particularly interesting for clinical applications, by using an internal standard and applying a 23 full factorial design. A volume of sample (250 ml) was loaded at 50 ml min-1 into a Tenax GR sorbent tube containing 130 nmol of O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride. All compounds showed a limit of detection lower than 200 pptv. The yield of the derivatization procedure was normalized by adding to the sample a known amount of 6D-acetone as an internal standard. This allowed halving the relative standard deviation to 10% and 15% for the mono-and di-carbonyl compounds, respectively, thus improving reliability. The optimized method was applied to the determination of carbonyl compounds in 12 breath samples collected from four patients suffering from heart failure during hospitalization.


Assuntos
Testes Respiratórios/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectrometria de Massas em Tandem/métodos , Temperatura , Calibragem , Insuficiência Cardíaca/diagnóstico , Humanos , Limite de Detecção , Modelos Lineares , Peso Molecular , Reprodutibilidade dos Testes
15.
Environ Sci Technol ; 52(10): 5734-5743, 2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29672036

RESUMO

Infiltration systems are treatment technologies based on water percolation through porous media where biogeochemical processes take place. Grain size distribution (GSD) acts as a driver of these processes and their rates and influences nutrient accumulation in sediments. Coarse sands inhibit anaerobic reactions such as denitrification and could constrain nutrient accumulation in sediments due to smaller specific surface area. Alternatively, fine sands provide higher nutrient accumulation but need a larger area available to treat the same volume of water; furthermore, they are more susceptible to bioclogging. Combining both sand sizes in a bilayer system would allow infiltrating a greater volume of water and the occurrence of aerobic/anaerobic processes. We studied the performance of a bilayer coarse-fine system compared to a monolayer fine one-by triplicate-in an outdoor infiltration experiment to close the C-N-P cycles simultaneously in terms of mass balances. Our results confirm that the bilayer coarse-fine GSD promotes nutrient removal by physical adsorption and biological assimilation in sediments, and further it enhances biogeochemical process rates (2-fold higher than the monolayer system). Overall, the bilayer coarse-fine system allows treating a larger volume of water per surface unit achieving similar removal efficiencies as the fine system.


Assuntos
Nutrientes , Dióxido de Silício , Sedimentos Geológicos , Porosidade , Água
16.
Biofouling ; 34(2): 200-211, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29405091

RESUMO

Two non-destructive techniques, confocal laser scanning microscopy (CLSM) and planar optode (VisiSens imaging), were combined to relate the fine-scale spatial structure of biofilm components to real-time images of oxygen decay in aquatic biofilms. Both techniques were applied to biofilms grown for seven days at contrasting light and temperature (10/20°C) conditions. The geo-statistical analyses of CLSM images indicated that biofilm structures consisted of small (~100 µm) and middle sized (~101 µm) irregular aggregates. Cyanobacteria and EPS (extracellular polymeric substances) showed larger aggregate sizes in dark grown biofilms while, for algae, aggregates were larger in light-20°C conditions. Light-20°C biofilms were most dense while 10°C biofilms showed a sparser structure and lower respiration rates. There was a positive relationship between the number of pixels occupied and the oxygen decay rate. The combination of optodes and CLMS, taking advantage of geo-statistics, is a promising way to relate biofilm architecture and metabolism at the micrometric scale.


Assuntos
Biofilmes/crescimento & desenvolvimento , Processamento de Imagem Assistida por Computador , Microscopia Confocal , Oxigênio/análise , Biofilmes/classificação , Biopolímeros/análise , Clorófitas/química , Clorófitas/crescimento & desenvolvimento , Cianobactérias/química , Cianobactérias/crescimento & desenvolvimento , Espaço Extracelular/química
17.
Dalton Trans ; 47(9): 2976-2985, 2018 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-29182170

RESUMO

The chloride form of MgAl layered double hydroxide (hereafter MgAlCl) as an anion exchanger and the semisodic form of α-zirconium phosphate (hereafter ZrPNaH) as a cation exchanger are proposed as new cleaning agents for the removal of gypsum from ancient monuments. The ability of these exchangers to capture the calcium and sulphate ions of the gypsum powder was first investigated separately and then as a coupled system. MgAlCl/gypsum, ZrPNaH/gypsum and MgAlCl/ZrPNaH/gypsum mixtures were characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and dispersive X-ray spectroscopy (EDX). ZrPNaH in the form of a wet paste exhibited a rapid uptake of calcium from gypsum powder via Na+ and H+/Ca2+ cation exchange. Gypsum powder was also successfully dissolved by a wet paste of MgAlCl by exploiting the Cl-/SO42- anion exchange reaction. However, the dehydration of the paste favoured the reprecipitation of a secondary gypsum that was characterized by lower crystallinity and smaller particle size than the pristine gypsum. The combination of wet MgAlCl and ZrPNaH showed a synergic effect on the dissolution of gypsum and partially prevented the reprecipitation of gypsum in the dry paste. Finally, a preliminary test of the removal of gypsum crust grown on a sandstone sample was performed.

19.
Environ Sci Technol ; 51(11): 6110-6119, 2017 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-28481089

RESUMO

Physical heterogeneity determines interstitial fluxes in porous media. Nutrients and organic matter distribution in depth influence physicochemical and microbial processes occurring in subsurface. Columns 50 cm long were filled with sterile silica sand following five different setups combining fine and coarse sands or a mixture of both mimicking potential water treatment barriers. Water was supplied continuously to all columns during 33 days. Hydraulic conductivity, nutrients and organic matter, biofilm biomass, and activity were analyzed in order to study the effect of spatial grain size heterogeneity on physicochemical and microbial processes and their mutual interaction. Coarse sediments showed higher biomass and activity in deeper areas compared to the others; however, they resulted in incomplete denitrification, large proportion of dead bacteria in depth, and low functional diversity. Treatments with fine sediment in the upper 20 cm of the columns showed high phosphorus retention. However, low hydraulic conductivity values reported in these sediments seemed to constraint biofilm activity and biomass. On the other hand, sudden transition from coarse-to-fine grain sizes promoted a hot-spot of organic matter degradation and biomass growth at the interface. Our results reinforce the idea that grain-size disposition in subsurface sandy sediments drives the interstitial fluxes, influencing microbial processes.


Assuntos
Bactérias , Fósforo , Microbiologia da Água , Biomassa , Sedimentos Geológicos
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