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1.
Acta Diabetol ; 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38743078

RESUMO

AIM: To analyze the prevalence of anxiety and depression in a large cohort of adults with autoimmune diabetes, identifying sex-driven associated factors. MATERIALS AND METHODS: In this cross-sectional study, we enrolled 553 consecutive adults with Type 1 diabetes mellitus or latent autoimmune diabetes in adults who came to the Division of Endocrinology of the S.Orsola-Malpighi Polyclinic, Bologna (Italy), to receive their second dose of SARS-CoV-2 vaccine. We administered the questionnaires: Hospital Anxiety and Depression Scale, Diabetes Distress Scale, Diabetes-related Quality of Life, Diabetes Treatment Satisfaction Questionnaire. We collected clinical and biochemical data and 14 days glucose metrics in patients with sensor use > 70% in a time span of ± 4 months from the questionnaires' administration. We excluded 119 patients from our analyses with missing data (final cohort n = 434: 79% of those enrolled). RESULTS: Anxiety and depression prevalence was respectively 30.4% and 10.8%. According to the multivariate analysis, higher diabete-related emotional burden, lower treatment satisfaction, but not physician-related distress, were risk factors for anxiety and depression; female sex was associated with anxiety (OR 0.51, 95% 0.31-0.81; p = 0.005); in women, depression was associated with increasing age (males vs. females OR 0.96 per 1 year increase, 95% CI 0.92-1.00; p = 0.036), whilst in men with HbA1c (OR 1.08 per 1 mmol/mol increase, 95% CI 1.03-1.13; p = 0.002). CONCLUSION: Nearly 1/3 of patients with autoimmune diabetes suffers from anxiety and 1/10 from depression. These conditions are associated with independent modifiable and non-modifiable characteristics. For depression, these characteristics differ between males and females.

2.
J Phys Chem Lett ; 15(9): 2392-2399, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38394035

RESUMO

Fucoxanthin Chlorophyll Protein (FCP) is a Light Harvesting Complex found in diatoms and brown algae. It is particularly interesting for its efficiency in capturing the blue-green part of the light spectrum due to the presence of specific chromophores (fucoxanthin, chlorophyll a, and chlorophyll c). Recently, the crystallographic structure of FCP was solved, revealing the 3D arrangement of the pigments in the protein scaffold. While this information is helpful for interpreting the spectroscopic features of FCP, it has also raised new questions about the potential interactions between fucoxanthin and chlorophyll c. These interactions were suggested by their spatial closeness but have never been experimentally observed. To investigate this possible interaction mechanism, in this work, two-dimensional electronic spectroscopy (2DES) has been applied to study the ultrafast relaxation dynamics of FCP. The experiments captured an instantaneous delocalization of the excitation among fucoxanthin and chlorophyll c, suggesting the presence of a non-negligible coupling between the chromophores.


Assuntos
Clorofila , Xantofilas , Clorofila A , Clorofila/química , Análise Espectral , Xantofilas/química , Complexos de Proteínas Captadores de Luz/química
3.
Photosynth Res ; 159(2-3): 133-152, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37191762

RESUMO

Photo-induced triplet states in the thylakoid membranes isolated from the cyanobacterium Acaryocholoris marina, that harbours Chlorophyll (Chl) d as its main chromophore, have been investigated by Optically Detected Magnetic Resonance (ODMR) and time-resolved Electron Paramagnetic Resonance (TR-EPR). Thylakoids were subjected to treatments aimed at poising the redox state of the terminal electron transfer acceptors and donors of Photosystem II (PSII) and Photosystem I (PSI), respectively. Under ambient redox conditions, four Chl d triplet populations were detectable, identifiable by their characteristic zero field splitting parameters, after deconvolution of the Fluorescence Detected Magnetic Resonance (FDMR) spectra. Illumination in the presence of the redox mediator N,N,N',N'-Tetramethyl-p-phenylenediamine (TMPD) and sodium ascorbate at room temperature led to a redistribution of the triplet populations, with T3 (|D|= 0.0245 cm-1, |E|= 0.0042 cm-1) becoming dominant and increasing in intensity with respect to untreated samples. A second triplet population (T4, |D|= 0.0248 cm-1, |E|= 0.0040 cm-1) having an intensity ratio of about 1:4 with respect to T3 was also detectable after illumination in the presence of TMPD and ascorbate. The microwave-induced Triplet-minus-Singlet spectrum acquired at the maximum of the |D|-|E| transition (610 MHz) displays a broad minimum at 740 nm, accompanied by a set of complex spectral features that overall resemble, despite showing further fine spectral structure, the previously reported Triplet-minus-Singlet spectrum attributed to the recombination triplet of PSI reaction centre, 3 P 740 [Schenderlein M, Çetin M, Barber J, et al. Spectroscopic studies of the chlorophyll d containing photosystem I from the cyanobacterium Acaryochloris marina. Biochim Biophys Acta 1777:1400-1408]. However, TR-EPR experiments indicate that this triplet displays an eaeaea electron spin polarisation pattern which is characteristic of triplet sublevels populated by intersystem crossing rather than recombination, for which an aeeaae polarisation pattern is expected instead. It is proposed that the observed triplet, which leads to the bleaching of the P740 singlet state, sits on the PSI reaction centre.


Assuntos
Cianobactérias , Complexo de Proteína do Fotossistema I , Tilacoides , Tilacoides/química , Complexo de Proteína do Fotossistema I/química , Clorofila/química , Complexo de Proteína do Fotossistema II/química , Espectroscopia de Ressonância de Spin Eletrônica
4.
Phys Chem Chem Phys ; 25(42): 28998-29016, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37859550

RESUMO

The influence of carotenoid triplet states on the Qy electronic transitions of chlorophylls has been observed in experiments on light-harvesting complexes over the past three decades, but the interpretation of the resulting spectral feature in the triplet minus singlet (T-S) absorption spectra of photosystems is still debated, as the physical-chemical explanation of this feature has been elusive. Here, we resolve this debate, by explaining the T-S spectra of pigment complexes over the Qy-band spectral region through a comparative study of chlorophyll-carotenoid model dyads and larger pigment complexes from the main light harvesting complex of higher plants (LHCII). This goal is achieved by combining state-of-the-art time-dependent density functional theory with analysis of the relationship between electronic properties and nuclear structure, and by comparison to the experiment. We find that the special signature in the T-S spectra of both model and natural photosystems is determined by singlet-like triplet excitations that can be described as effective singlet excitations on chlorophylls influenced by a stable electronic triplet on the carotenoid. The comparison with earlier experiments on different light-harvesting complexes confirms our theoretical interpretation of the T-S spectra in the Qy spectral region. Our results indicate an important role for the chlorophyll-carotenoid electronic coupling, which is also responsible for the fast triplet-triplet energy transfer, suggesting a fast trapping of the triplet into the relaxed carotenoid structure. The gained understanding of the interplay between the electronic and nuclear structures is potentially informative for future studies of the mechanism of photoprotection by carotenoids.

5.
Biochim Biophys Acta Bioenerg ; 1864(4): 149002, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37562512

RESUMO

In cyanobacteria that undergo far red light photoacclimation (FaRLiP), chlorophyll (Chl) f is produced by the ChlF synthase enzyme, probably by photo-oxidation of Chl a. The enzyme forms homodimeric complexes and the primary amino acid sequence of ChlF shows a high degree of homology with the D1 subunit of photosystem II (PSII). However, few details of the photochemistry of ChlF are known. The results of a mutational analysis and optically detected magnetic resonance (ODMR) data from ChlF are presented. Both sets of data show that there are significant differences in the photochemistry of ChlF and PSII. Mutation of residues that would disrupt the donor side primary electron transfer pathway in PSII do not inhibit the production of Chl f, while alteration of the putative ChlZ, P680 and QA binding sites rendered ChlF non-functional. Together with previously published transient EPR and flash photolysis data, the ODMR data show that in untreated ChlF samples, the triplet state of P680 formed by intersystem crossing is the primary species generated by light excitation. This is in contrast to PSII, in which 3P680 is only formed by charge recombination when the quinone acceptors are removed or chemically reduced. The triplet states of a carotenoid (3Car) and a small amount of 3Chl f are also observed by ODMR. The polarization pattern of 3Car is consistent with its formation by triplet energy transfer from ChlZ if the carotenoid molecule is rotated by 15° about its long axis compared to the orientation in PSII. It is proposed that the singlet oxygen formed by the interaction between molecular oxygen and 3P680 might be involved in the oxidation of Chl a to Chl f.


Assuntos
Clorofila , Complexo de Proteína do Fotossistema II , Complexo de Proteína do Fotossistema II/metabolismo , Clorofila/metabolismo , Clorofila A , Carotenoides/química , Óxido Nítrico Sintase , Espectroscopia de Ressonância Magnética
6.
Endocr Connect ; 12(7)2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37018117

RESUMO

Objective: The aim of this study isto assess the efficacy of a very low-calorie ketogenic diet (VLCKD) method vs a Mediterranean low-calorie diet (LCD) in obese polycystic ovary syndrome (PCOS) women of a reproductive age. Design: Randomized controlled open-label trial was performed in this study. The treatment period was 16 weeks; VLCKD for 8 weeks then LCD for 8 weeks, according to the Pronokal® method (experimental group; n = 15) vs Mediterranean LCD for 16 weeks (control group; n = 15). Ovulation monitoring was carried out at baseline and after 16 weeks, while a clinical exam, bioelectrical impedance analysis (BIA), anthropometry, and biochemical analyses were performed at baseline, at week 8, and at week 16. Results: BMI decreased significantly in both groups and to a major extent in the experimental group (-13.7% vs -5.1%, P = 0.0003). Significant differences between the experimental and the control groups were also observed in the reduction of waist circumference (-11.4% vs -2.9%), BIA-measured body fat (-24.0% vs -8.1%), and free testosterone (-30.4% vs -12.6%) after 16 weeks (P = 0.0008, P = 0.0176, and P = 0.0009, respectively). Homeostatic model assessment for insulin resistance significantly decreased only in the experimental group (P = 0.0238) but without significant differences with respect to the control group (-23% vs -13.2%, P > 0.05). At baseline, 38.5% of participants in the experimental group and 14.3% of participants in the control group had ovulation, which increased to 84.6% (P = 0.031) and 35.7% (P > 0.05) at the end of the study, respectively. Conclusion: In obese PCOS patients, 16 weeks of VLCKD protocol with the Pronokal® method was more effective than Mediterranean LCD in reducing total and visceral fat, and in ameliorating hyperandrogenism and ovulatory dysfunction. Significance statements: To the best of our knowledge, this is the first randomized controlled trial on the use of the VLCKD method in obese PCOS. It demonstrates the superiority of VLCKD with respect to Mediterranean LCD in reducing BMI with an almost selective reduction of fat mass and a unique effect of VLCKD in reducing visceral adiposity, insulin resistance, and in increasing SHBG with a consequent reduction of free testosterone. Interestingly, this study also demonstrates the superiority of the VLCKD protocol in improving ovulation, whose occurrence increased by 46.1% in the group treated by the VLCKD method against a rise of 21.4% in the group treated by Mediterranean LCD. This study extends the therapeutic approach possibilities in obese PCOS women.

7.
Inflamm Bowel Dis ; 29(8): 1297-1305, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-36897213

RESUMO

BACKGROUND: Crohn's disease (CD) is an inflammatory, chronic disorder that alternates between a quiescent phase and inflammatory flare-ups. Research has begun to elucidate the impact of CD in modulating brain structure and function. The previous neuroimaging studies mainly involved CD patients in remission (CD-R); therefore, little is known about how inflammation influences brain-related features in different stages of the disease. We carried out a magnetic resonance imaging (MRI) study to explore whether the different levels of disease activity may differentially affect brain structure and function. METHODS: Fourteen CD-R patients, 19 patients with mild to moderate inflammatory activity (CD-A), and 18 healthy controls (HCs) underwent an MRI scan including structural and functional sequences. RESULTS: Between-group comparisons showed morphological and functional brain differences distinctively associated with the stage of disease activity. The CD-A patients had reduced gray matter within the posterior cingulate cortex (PCC) relative to CD-R patients. Analysis on resting fMRI data showed the following patterns: (1) increased connectivity within the left fronto-parietal network (in the superior parietal lobe) in CD-R patients relative to CD-A patients; (2) decreased connectivity in the motor network (in parietal and motor areas) in the CD-A group relative to the HC group; (3) reduced connectivity in the motor network and (4) in the language network (in parietal areas and in the PCC) in CD-R patients relative to HC. CONCLUSIONS: The present findings represent a further step towards understanding brain morphological and functional changes in the active vs remission stages of CD patients.


We found morphological and functional brain changes associated with different stages of disease activity in Crohn's disease. These findings may represent the neural correlates of fatigue, irritable bowel syndrome­like symptoms, and cognitive-emotional impairments; these could be useful for evaluating disease progression.


Assuntos
Doença de Crohn , Humanos , Doença de Crohn/patologia , Vias Neurais , Encéfalo , Imageamento por Ressonância Magnética
8.
Biochim Biophys Acta Bioenerg ; 1864(2): 148935, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36379269

RESUMO

Detailed information on the photo-generated triplet states of diatom and haptophyte Fucoxanthin Chlorophyll-binding Proteins (FCPs and E-FCPs, respectively) have been obtained from a combined spectroscopic investigation involving Transient Absorption and Time-Resolved Electron Paramagnetic Resonance. Pennate diatom Phaeodactylum tricornutum FCP shows identical photoprotective Triplet-Triplet Energy Transfer (TTET) pathways to the previously investigated centric diatom Cyclotella meneghiniana FCP, with the same two chlorophyll a-fucoxanthin pairs that involve the fucoxanthins in sites Fx301 and Fx302 contributing to TTET in both diatom groups. In the case of the haptophyte Emilianina huxleyi E-FCP, only one of the two chlorophyll a-fucoxanthins pairs observed in diatoms, the one involving chlorophyll a409 and Fx301, has been shown to be active in TTET. Furthermore, despite the marked change in the pigment content of E-FCP with growth light intensity, the TTET pathway is not affected. Thus, our comparative investigation of FCPs revealed a photoprotective TTET pathway shared within these classes involving the fucoxanthin in site Fx301, a site exposed to the exterior of the antenna monomer that has no equivalent in Light-Harvesting Complexes from the green lineage.


Assuntos
Proteínas de Ligação à Clorofila , Diatomáceas , Proteínas de Ligação à Clorofila/química , Clorofila A/metabolismo , Clorofila/metabolismo , Diatomáceas/química , Espectroscopia de Ressonância de Spin Eletrônica , Transferência de Energia
9.
BMC Med ; 20(1): 500, 2022 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-36575453

RESUMO

BACKGROUND: Obesity and related co-morbidities represent a major health challenge nowadays, with a rapidly increasing incidence worldwide. The gut microbiome has recently emerged as a key modifier of human health that can affect the development and progression of obesity, largely due to its involvement in the regulation of food intake and metabolism. However, there are still few studies that have in-depth explored the functionality of the human gut microbiome in obesity and even fewer that have examined its relationship to eating behaviors. METHODS: In an attempt to advance our knowledge of the gut-microbiome-brain axis in the obese phenotype, we thoroughly characterized the gut microbiome signatures of obesity in a well-phenotyped Italian female cohort from the NeuroFAST and MyNewGut EU FP7 projects. Fecal samples were collected from 63 overweight/obese and 37 normal-weight women and analyzed via a multi-omics approach combining 16S rRNA amplicon sequencing, metagenomics, metatranscriptomics, and lipidomics. Associations with anthropometric, clinical, biochemical, and nutritional data were then sought, with particular attention to cognitive and behavioral domains of eating. RESULTS: We identified four compositional clusters of the gut microbiome in our cohort that, although not distinctly associated with weight status, correlated differently with eating habits and behaviors. These clusters also differed in functional features, i.e., transcriptional activity and fecal metabolites. In particular, obese women with uncontrolled eating behavior were mostly characterized by low-diversity microbial steady states, with few and poorly interconnected species (e.g., Ruminococcus torques and Bifidobacterium spp.), which exhibited low transcriptional activity, especially of genes involved in secondary bile acid biosynthesis and neuroendocrine signaling (i.e., production of neurotransmitters, indoles and ligands for cannabinoid receptors). Consistently, high amounts of primary bile acids as well as sterols were found in their feces. CONCLUSIONS: By finding peculiar gut microbiome profiles associated with eating patterns, we laid the foundation for elucidating gut-brain axis communication in the obese phenotype. Subject to confirmation of the hypotheses herein generated, our work could help guide the design of microbiome-based precision interventions, aimed at rewiring microbial networks to support a healthy diet-microbiome-gut-brain axis, thus counteracting obesity and related complications.


Assuntos
Microbioma Gastrointestinal , Humanos , Feminino , Microbioma Gastrointestinal/genética , RNA Ribossômico 16S/genética , Multiômica , Obesidade/genética , Dieta , Comportamento Alimentar/fisiologia , Fezes/microbiologia
10.
J Contextual Behav Sci ; 26: 44-55, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36060527

RESUMO

The COVID-19 pandemic evokes high levels of post-traumatic stress (PTS) in some people as well as positive personal changes, a phenomenon known as post-traumatic growth (PTG). Experiencing an adverse event as traumatic is crucial for triggering PTG, therefore higher PTS is often associated with higher PTG. This longitudinal study examined the protective role of psychological flexibility in fostering PTG in a group of people reporting high PTS related to COVID-19 as compared to those with low PTS. We hypothesized that higher psychological flexibility will be associated with higher PTG in those with high PTS and that psychological flexibility would be unrelated to PTG in those with low PTS. Secondary data analysis was conducted on data from a larger project investigating the psychological impacts of COVID-19. Adult Italians (N = 382) completed online surveys at Time 1 (three months after the first national lockdown, July 2020) and Time 2 (three months later when the number of COVID-19 cases increased, October 2020). Based on the Impact of Event Scale-Revised cut-off score, two PTS groups were identified at Time 2: low PTS (below cut-off) and high PTS (above cut-off). As predicted, moderation analyses showed that after controlling for Time 1 PTS and PTG and confounding variables, Time 1 psychological flexibility was associated with higher Time 2 PTG in the high PTS group, whereas psychological flexibility was unrelated to PTG in the low PTS group. Four psychological flexibility sub-processes (present moment awareness, defusion, values, committed action) at Time 1 were related to higher Time 2 PTG in only the high PTS group. Findings advance understanding of the role of psychological flexibility in trauma reactions and pandemic mental health adjustment. Evidence-based approaches that target psychological flexibility, like Acceptance and Commitment Therapy, are likely to foster PTG and ultimately adjustment in people with high PTS during and after the pandemic.

11.
Molecules ; 27(12)2022 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-35744779

RESUMO

A magnetophotoselection (MPS) investigation of the photoexcited triplet state of chlorophyll a both in a frozen organic solvent and in a protein environment, provided by the water-soluble chlorophyll protein (WSCP) of Lepidium virginicum, is reported. The MPS experiment combines the photoselection achieved by exciting with linearly polarized light with the magnetic selection of electron paramagnetic resonance (EPR) spectroscopy, allowing the determination of the relative orientation of the optical transition dipole moment and the zero-field splitting tensor axes in both environments. We demonstrate the robustness of the proposed methodology for a quantitative description of the excitonic interactions among pigments. The orientation of the optical transition dipole moments determined by the EPR analysis in WSCP, identified as an appropriate model system, are in excellent agreement with those calculated in the point-dipole approximation. In addition, MPS provides information on the electronic properties of the triplet state, localized on a single chlorophyll a pigment of the protein cluster, in terms of orientation of the zero-field splitting tensor axes in the molecular frame.


Assuntos
Clorofila , Lepidium , Clorofila/química , Clorofila A/metabolismo , Espectroscopia de Ressonância de Spin Eletrônica , Lepidium/metabolismo , Complexos de Proteínas Captadores de Luz/química , Água/química
12.
Int J Mol Sci ; 23(9)2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35563202

RESUMO

Carotenoids represent the first line of defence of photosystems against singlet oxygen (1O2) toxicity, because of their capacity to quench the chlorophyll triplet state (3Chl) through a physical mechanism based on the transfer of triplet excitation (triplet-triplet energy transfer, TTET). In previous works, we showed that the antenna LHCII is characterised by a robust photoprotective mechanism, able to adapt to the removal of individual chlorophylls while maintaining a remarkable capacity for 3Chl quenching. In this work, we investigated the effects on this quenching induced in LHCII by the replacement of the lutein bound at the L1 site with violaxanthin and zeaxanthin. We studied LHCII isolated from the Arabidopsis thaliana mutants lut2-in which lutein is replaced by violaxanthin-and lut2 npq2, in which all xanthophylls are replaced constitutively by zeaxanthin. We characterised the photophysics of these systems via optically detected magnetic resonance (ODMR) and time-resolved electron paramagnetic resonance (TR-EPR). We concluded that, in LHCII, lutein-binding sites have conserved characteristics, and ensure efficient TTET regardless of the identity of the carotenoid accommodated.


Assuntos
Arabidopsis , Luteína , Arabidopsis/metabolismo , Carotenoides/metabolismo , Clorofila/metabolismo , Transferência de Energia , Complexos de Proteínas Captadores de Luz/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Xantofilas/química , Zeaxantinas/metabolismo
13.
Photosynth Res ; 152(2): 213-234, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35290567

RESUMO

The photoexcited triplet state of the "primary donors" in the two photosystems of oxygenic photosynthesis has been investigated by means of electron-nuclear double resonance (ENDOR) at Q-band (34 GHz). The data obtained represent the first set of 1H hyperfine coupling tensors of the 3P700 triplet state in PSI and expand the existing data set for 3P680. We achieved an extensive assignment of the observed electron-nuclear hyperfine coupling constants (hfcs) corresponding to the methine α-protons and the methyl group ß-protons of the chlorophyll (Chl) macrocycle. The data clearly confirm that in both photosystems the primary donor triplet is located on one specific monomeric Chl at cryogenic temperature. In comparison to previous transient ENDOR and pulse ENDOR experiments at standard X-band (9-10 GHz), the pulse Q-band ENDOR spectra demonstrate both improved signal-to-noise ratio and increased resolution. The observed ENDOR spectra for 3P700 and 3P680 differ in terms of the intensity loss of lines from specific methyl group protons, which is explained by hindered methyl group rotation produced by binding site effects. Contact analysis of the methyl groups in the PSI crystal structure in combination with the ENDOR analysis of 3P700 suggests that the triplet is located on the Chl a' (PA) in PSI. The results also provide additional evidence for the localization of 3P680 on the accessory ChlD1 in PSII.


Assuntos
Complexo de Proteína do Fotossistema I , Prótons , Clorofila A , Espectroscopia de Ressonância de Spin Eletrônica , Fotossíntese
14.
Healthcare (Basel) ; 9(11)2021 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-34828621

RESUMO

(1) Background. In caretaking professions, attachment style and mentalization capacities are essential factors for establishing an effective caretaker-patient relationship and for buffering burnout. While attachment avoidance and dependency are considered risk factors for burnout, impairment in mentalization capacity is associated with psychological distress and ineffective emotion regulation. (2) Objective: Evaluating the attachment style and mentalization capacity in nurse professionals and nursing students. We further investigated the impact of these factors on burnout in professional nurses. (3) Method: 94 nursing students and 94 controls and 34 professional nurses completed the Attachment Style Questionnaire (ASQ) and the Reflective Functioning Questionnaire (RFQ). For professional nurses, the Maslach's Burnout Inventory (MBI) was also administered. (4) Results: Nursing students exhibited lower scores in secure attachment and higher scores in anxiety over relationships compared to controls while no difference in mentalization capacity was found between both groups. Importantly, attachment anxiety resulted a significant predictor of burnout in professional nurses. (5) Conclusions: Nursing students might compensate their attachment insecurity with high mentalization. Attachment security may play a protective role against burnout in the professional nurses. Education programs aimed at enhancing mentalizing abilities might facilitate nursing students' entrance in the forthcoming clinical environment and practice. Implementing training strategies based on attachment theory may contribute to burnout prevention in nurse professionals.

15.
Biochim Biophys Acta Bioenerg ; 1862(11): 148481, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34363791

RESUMO

The triplet states populated under illumination in the monomeric light-harvesting complex II (LHCII) were analyzed by EPR and Optically Detected Magnetic Resonance (ODMR) in order to fully characterize the perturbations introduced by site-directed mutations leading to the removal of key chlorophylls. We considered the A2 and A5 mutants, lacking Chls a612(a611) and Chl a603 respectively, since these Chls have been proposed as the sites of formation of triplet states which are subsequently quenched by the luteins. Chls a612 and Chl a603 belong to the two clusters determining the low energy exciton states in the complex. Their removal is expected to significantly alter the excitation energy transfer pathways. On the basis of the TR- and pulse EPR triplet spectra, the two symmetrically related pairs constituted by Chl a612/Lut620 and Chl a603/Lut621 were both possible candidate for triplet-triplet energy transfer (TTET). However, the ODMR results clearly show that only Lut620 is involved in triplet quenching. In the A5 mutant, the Chl a612/Lut620 pair retains this pivotal photoprotective role, while the A2 mutant was found to activate an alternative pathway involving the Chl a603/Lut621pair. These results shows that LHCII is characterized by a robust photoprotective mechanism, able to adapt to the removal of individual chromophores while maintaining a remarkable degree of Chl triplet quenching. Small amounts of unquenched Chl triplet states were also detected. The analysis of the results allowed us to assign the sites of "unquenched" chlorophyll triplets to Chl a610 and Chl a602.


Assuntos
Carotenoides/química , Clorofila/química , Complexos de Proteínas Captadores de Luz/química , Sequência de Aminoácidos , Espectroscopia de Ressonância de Spin Eletrônica , Transferência Ressonante de Energia de Fluorescência , Espectroscopia de Ressonância Magnética , Processos Fotoquímicos , Fotossíntese , Conformação Proteica , Relação Estrutura-Atividade
16.
Photochem Photobiol Sci ; 20(6): 747-759, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34018156

RESUMO

The type-I, homodimeric photosynthetic reaction center (RC) of Heliobacteria (HbRC) is the only known RC in which bacteriochlorophyll g (BChl g) is found. It is also simpler than other RCs, having the smallest number of protein subunits and bound chromophores of any type-I RC. In the presence of oxygen, BChl g isomerizes to 81-hydroxychlorophyll aF (Chl aF). This naturally occurring process provides a way of altering the chlorophylls and studying the effect of these changes on energy and electron transfer. Transient absorbance difference spectroscopy reveals that triplet-state formation occurs in the antenna chlorophylls of HbRCs but does not provide site-specific information. Here, we report on an extended optically detected magnetic resonance (ODMR) study of the antenna triplet states in HbRCs with differing levels of conversion of BChl g to Chl aF. The data reveal pools of BChl g molecules with different triplet zero-field splitting parameters and different susceptibilities to chemical oxidation. By relating the detailed spectroscopic characteristics derived from the ODMR data to the recently solved crystallographic structure, we have tentatively identified BChl g molecules in which the probability of triplet formation is high and sites at which BChl g conversion is more likely, providing useful information about the fate of the excitation in the complex.


Assuntos
Bacterioclorofilas/química , Clostridiales/química , Oxigênio/análise , Bacterioclorofilas/metabolismo , Clostridiales/metabolismo , Espectroscopia de Ressonância Magnética , Oxigênio/metabolismo
17.
Biochim Biophys Acta Bioenerg ; 1862(1): 148310, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32991847

RESUMO

Fucoxanthin chlorophyll-binding proteins (FCPs) are the major light-harvesting complexes of diatoms. In this work, FCPs isolated from Cyclotella meneghiniana have been studied by means of optically detected magnetic resonance (ODMR) and time-resolved electron paramagnetic resonance (TR-EPR), with the aim to characterize the photoprotective mechanism based on triplet-triplet energy transfer (TTET). The spectroscopic properties of the chromophores carrying the triplet state have been interpreted on the basis of a delved analysis of the recently solved crystallographic structures of FCP. The results point toward a photoprotective role for two fucoxanthin molecules exposed to the exterior of the FCP monomers. This shows that FCP has adopted a structural strategy different from that of related light-harvesting complexes from plants and other microalgae, in which the photoprotective role is carried out by two highly conserved carotenoids in the interior of the complex.


Assuntos
Proteínas de Ligação à Clorofila/química , Estramenópilas/química , Proteínas de Ligação à Clorofila/metabolismo , Espectroscopia de Ressonância de Spin Eletrônica , Estramenópilas/metabolismo
18.
Med Hypotheses ; 140: 109665, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32155541

RESUMO

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, are chronic intestinal disorders that requires lifelong treatments. IBD are associated with perceived stress, poor quality of life, and psychopathological disorders. Previous studies have documented that psychological distress and depression are risk factors for IBD. On the other hand, IBD itself might be a source of psychological stress. IBD negatively affect individuals' daily social interactions and close interpersonal relationships. Despite IBD's detrimental effects on quality of life, patients' adherence to medicaments remains low, increasing the risk of relapses and the subsequent worsening of the clinical condition. Drawing on attachment and mentalization theories, we aim to contribute to understanding of the mechanisms involved in the poor quality of social relationships and the tendency for medication non-adherence in patients with IBD. We hypothesize a bidirectional link between IBD and attachment style and related mentalization abilities, where an individual's attachment style refers to a complex and characteristic pattern of relating to self and others and mentalization refers to the process of inferring one's own and others' mental and physical states. This hypothesized link between IBD and insecure attachment style, mediated by reduced mentalizing abilities, may be a risk factor for developing both IBD-related psychological disorders and reduced medication adherence, which could then lead to worsening disease management and prognoses for the disease course. The medication nonadherence is here considered as both an outcome and a risk factor of this vicious circle. We share the view that preventing the worsening of the IBD condition and promoting patients' medication adherence would be possible by considering the circular relationship between IBD, attachment, and mentalization and by promoting reflective functioning in patients with IBD, from the onset of the disease.

19.
J Phys Chem Lett ; 11(3): 1059-1067, 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-31952446

RESUMO

The interplay between active molecules and the protein environment in light-harvesting complexes tunes the photophysics and the dynamical properties of pigment-protein complexes in a subtle way, which is not fully understood. Here we characterized the photophysics and the ultrafast dynamics of four variants of the water-soluble chlorophyll protein (WSCP) as an ideal model system to study the behavior of strongly interacting chlorophylls. We found that when coordinated by the WSCP protein, the presence of the formyl group in chlorophyll b replacing the methyl group in chlorophyll a strongly affects the exciton energy and the dynamics of the system, opening up the possibility of tuning the photophysics and the transport properties of multichromophores by engineering specific interactions with the surroundings.


Assuntos
Clorofila A/química , Clorofila/química , Complexos de Proteínas Captadores de Luz/química , Modelos Moleculares , Temperatura , Termodinâmica , Água/química
20.
Adv Health Sci Educ Theory Pract ; 25(4): 799-808, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-31960188

RESUMO

Medical students' motivations for choosing a medical career are likely based on and remain tethered to the affectively-laden caring component of doctor-patient interactions. However, this component is rarely presented in educational surgical videos. It is unknown whether affectively engaging students by including patient-related emotionally salient information potentiates or draws focus away from learning a surgical procedure and whether such information affects motivation and attitudes toward the video. Therefore, we investigate whether presenting a patient's emotional state before video surgery enhances or weakens the educational value of that video. In a within-subjects crossover design, second-year medical students (n = 130) viewed video clips of surgeries. These videos, from online medical education platforms, were preceded by the patient's information from the original video or by information about the patient's preoperative emotional preparation. After each video, participants completed a multiple-choice test about the video's content to measure learning, answered a question about their motivation to re-watch the video, and completed an attitude scale regarding the video. Incorporating patient's information into surgical videos significantly enhanced students' acquisition of the technical aspects of surgery procedures (p < 0.0001), motivation to re-watch the video (p < 0.001), and favorable attitudes toward the video (p = 0.02). These findings show that incorporating information about patients' emotional states may enhance students' positive attitudes and motivations toward educational videos and may improve their learning of surgical techniques. They also suggest that the role of this factor should be considered when developing guidelines for medical educational video release.


Assuntos
Educação Médica/métodos , Emoções , Pacientes/psicologia , Procedimentos Cirúrgicos Operatórios/educação , Gravação em Vídeo , Atitude do Pessoal de Saúde , Competência Clínica , Estudos Cross-Over , Feminino , Humanos , Aprendizagem , Masculino , Motivação , Adulto Jovem
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