RESUMO
CONTEXT: Health simulation is a recognized educational method for teaching and validating surgical procedural skills. The latter requires the development of adapted assessment tools, reaching different validity criteria. The aim of this study was to validate a multimodal assessment tool for a complex skin suturing exercise, combining a manual knot, an intradermal linear suturing and a needle holder tied knot. METHODOLOGY: The suturing exercise was realized on a synthetic skin model by voluntary participants after having obtained their written consent, including 9 postgraduate medical students, 40 surgical residents of different levels of experience, and a group of 9 senior surgeons. The multimodal assessment tool (MAT) combined a checklist, a speed score and a global rating scale. Each exercise was scored by two evaluators. Medical students' performances were filmed anonymously so that they could be scored iteratively. Content validity was tested through a satisfaction questionnaire randomly completed by participants. RESULTS: The MAT was considered relevant or very relevant by 98% of the participants, with a better appreciation for the checklist than for the global rating scale. Internal consistency was strong with a Cronbach α coefficient at 0.78, and a good correlation between the results of the checklist and the global rating scale (r=0.79, P<0.0001). The MAT showed continuous improvement in mean scores from 34.4±3.6 for novices to 47.4±2.5/50 points for experts, passing through three intermediate levels groups, and allowed for significant discrimination between groups. The MAT was reliable, with a coefficient of correlation set at 0.88 for intra-observer reliability, and 0.72 for inter-observer reliability. On sub score analysis, the global rating scale and the speed score better discriminated between groups than the checklist, the latter moreover showing slightly lower reliability than the global rating scale. CONCLUSION: Despite its banality in any surgeon's practice and the fact that it is taught from the 2nd cycle of medical studies, suturing and its technical components have rarely been the subject of publications dedicated to the validation of specific assessment tools. Hence, this work on the MAT and its sub scores made it possible to validate them on many validity and reliability criteria. They can therefore be proposed to surgical teachers for evaluating a complex suturing exercise, with a checklist that is easier to use even for novices and a global rating scale showing better discrimination capacity.
RESUMO
INTRODUCTION: Microcirculatory alterations are key mechanisms in sepsis pathophysiology leading to tissue hypoxia, edema formation, and organ dysfunction. Hyperspectral imaging (HSI) is an emerging imaging technology that uses tissue-light interactions to evaluate biochemical tissue characteristics including tissue oxygenation, hemoglobin content and water content. Currently, clinical data for HSI technologies in critical ill patients are still limited. METHODS AND ANALYSIS: TIVITA® Tissue System was used to measure Tissue oxygenation (StO2), Tissue Hemoglobin Index (THI), Near Infrared Perfusion Index (NPI) and Tissue Water Index (TWI) in 25 healthy volunteers and 25 septic patients. HSI measurement sites were the palm, the fingertip, and a suprapatellar knee area. Septic patients were evaluated on admission to the ICU (E), 6 h afterwards (E+6) and three times a day (t3-t9) within a total observation period of 72 h. Primary outcome was the correlation of HSI results with daily SOFA-scores. RESULTS: Serial HSI at the three measurement sites in healthy volunteers showed a low mean variance expressing high retest reliability. HSI at E demonstrated significantly lower StO2 and NPI as well as higher TWI at the palm and fingertip in septic patients compared to healthy volunteers. StO2 and TWI showed corresponding results at the suprapatellar knee area. In septic patients, palm and fingertip THI identified survivors (E-t4) and revealed predictivity for 28-day mortality (E). Fingertip StO2 and THI correlated to SOFA-score on day 2. TWI was consistently increased in relation to the TWI range of healthy controls during the observation time. Palm TWI correlated positively with SOFA scores on day 3. DISCUSSION: HSI results in septic patients point to a distinctive microcirculatory pattern indicative of reduced skin oxygenation and perfusion quality combined with increased blood pooling and tissue water content. THI might possess risk-stratification properties and TWI could allow tissue edema evaluation in critically ill patients. CONCLUSION: HSI technologies could open new perspectives in microcirculatory monitoring by visualizing oxygenation and perfusion quality combined with tissue water content in critically ill patients - a prerequisite for future tissue perfusion guided therapy concepts in intensive care medicine.
Assuntos
Imageamento Hiperespectral , Microcirculação , Imagem de Perfusão , Testes Imediatos , Sepse/diagnóstico por imagem , Pele/irrigação sanguínea , Espectroscopia de Luz Próxima ao Infravermelho , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/metabolismo , Água Corporal/metabolismo , Estudos de Casos e Controles , Estado Terminal , Feminino , Hemoglobinas/metabolismo , Humanos , Imageamento Hiperespectral/instrumentação , Masculino , Pessoa de Meia-Idade , Escores de Disfunção Orgânica , Oxigênio/metabolismo , Imagem de Perfusão/instrumentação , Projetos Piloto , Sistemas Automatizados de Assistência Junto ao Leito , Valor Preditivo dos Testes , Estudos Prospectivos , Fluxo Sanguíneo Regional , Sepse/metabolismo , Sepse/fisiopatologia , Pele/metabolismo , Espectroscopia de Luz Próxima ao Infravermelho/instrumentação , Fatores de TempoRESUMO
BACKGROUND: Individuals with Down syndrome (DS) are at high risk for dementia, specifically Alzheimer's disease. However, many measures regularly used for the detection of dementia in the general population are not suitable for individuals with DS due in part to floor effects. Some measures, including the Severe Impairment Battery (SIB), Brief Praxis Test (BPT) and Dementia Scale for People with Learning Disabilities (DLD), have been used in clinical trials and other research with this population. Validity research is limited, particularly regarding the use of such tools for detection of prodromal dementia in the DS population. The current project presents baseline cross-sectional SIB, BPT and DLD performance in order to characterise their predictive utility in discriminating normal cognition, possible dementia and probable dementia in adult DS. METHOD: Baseline SIB, BPT and DLD performances from 100 individuals (no dementia = 68, possible dementia = 16 & probable dementia = 16) were examined from a longitudinal cohort of aging individuals with DS. Receiver operating characteristic curves investigated the accuracy of these measures in relation to consensus dementia diagnoses, diagnoses which demonstrated high percent agreement with the examining neurologist's independent diagnostic impression. RESULTS: The SIB and BPT exhibited fair discrimination ability for differentiating no/possible versus probable dementia [area under the curve (AUC) = 0.61 and 0.66, respectively]. The DLD exhibited good discrimination ability for differentiating no versus possible/probable dementia (AUC = 0.75) and further demonstrated better performance of the DLD Cognitive subscale compared with the DLD Social subscale (AUC = 0.77 and 0.67, respectively). CONCLUSIONS: Results suggest that the SIB, BPT and DLD are able to reasonably discriminate consensus dementia diagnoses in individuals with DS, supporting their continued use in the clinical assessment of dementia in DS. The general performance of these measures suggests that further work in the area of test development is needed to improve on the AUCs for dementia status discrimination in this unique population. At present, however, the current findings suggest that the DLD may be the best option for reliable identification of prodromal dementia in this population, reinforcing the importance of including informant behaviour ratings in assessment of cognition for adults with DS.
Assuntos
Doença de Alzheimer , Demência , Síndrome de Down , Deficiências da Aprendizagem , Adulto , Estudos Transversais , Demência/diagnóstico , Síndrome de Down/complicações , Síndrome de Down/diagnóstico , Humanos , Testes NeuropsicológicosRESUMO
Films of iron selenide (FeSe) one unit cell thick grown on strontium titanate (SrTiO3 or STO) substrates have recently shown superconducting energy gaps opening at temperatures close to the boiling point of liquid nitrogen (77 kelvin), which is a record for the iron-based superconductors. The gap opening temperature usually sets the superconducting transition temperature Tc, as the gap signals the formation of Cooper pairs, the bound electron states responsible for superconductivity. To understand why Cooper pairs form at such high temperatures, we examine the role of the SrTiO3 substrate. Here we report high-resolution angle-resolved photoemission spectroscopy results that reveal an unexpected characteristic of the single-unit-cell FeSe/SrTiO3 system: shake-off bands suggesting the presence of bosonic modes, most probably oxygen optical phonons in SrTiO3 (refs 5, 6, 7), which couple to the FeSe electrons with only a small momentum transfer. Such interfacial coupling assists superconductivity in most channels, including those mediated by spin fluctuations. Our calculations suggest that this coupling is responsible for raising the superconducting gap opening temperature in single-unit-cell FeSe/SrTiO3.
RESUMO
BACKGROUND: People with Down syndrome (DS) develop Alzheimer's disease (AD) at an earlier age of onset than those with sporadic AD. AD neuropathology is typically present in DS by 40 years of age with an onset of dementia approximately 10 years later. This early onset is due to the overexpression of amyloid precursor protein from the third copy of chromosome 21. Cerebrovascular neuropathology is thought to contribute in 40-60% of cases sporadic AD. However, the vascular contribution to dementia in people with DS has been relatively unexplored. We hypothesised that vascular perfusion is compromised in older adults with DS relative to younger individuals and is further exacerbated in those with dementia. METHOD: Cerebral blood flow (CBF) was measured using pulsed arterial spin labelling in 35 cognitively characterised adults with DS (26-65 years). DS participants were also compared with 15 control subjects without DS or dementia (26-65 years). Linear regression evaluated the difference in CBF across groups and diagnosis along with assessing the association between CBF and cognitive measures within the DS cohort. RESULTS: Cerebral blood flow was significantly lower among DS participants with probable AD compared with controls (P = 0.02) and DS participants with no dementia (P = 0.01). Within the DS cohort, CBF was significantly associated with the Severe Impairment Battery (SIB) measure and the Dementia Questionnaire for People with Learning Disabilities (DLD) rating (F3,25 = 5.13; P = 0.007). Both the SIB (ß = 0.74; t = 2.71; P = 0.01) and DLD (ß = -0.96; t = -3.87; P < 0.001) indicated greater impairment as global CBF decreased. Age was significantly associated with CBF among participants with DS. There was a non-linear effect of age, whereby CBF declined more rapidly after 45 years of age. CONCLUSIONS: This preliminary study of CBF in DS indicates that cerebrovascular pathology may be a significant contributor to dementia in DS. CBF was associated with diagnosis, cognition and age. Notably, CBF decreases at a greater rate after age 45 and may represent a significant prodromal event in AD progression.
Assuntos
Envelhecimento/fisiologia , Circulação Cerebrovascular/fisiologia , Demência/epidemiologia , Síndrome de Down/epidemiologia , Adulto , Idoso , Comorbidade , Demência/fisiopatologia , Síndrome de Down/fisiopatologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estados Unidos/epidemiologiaRESUMO
Breast male cancer is a rare condition. We report a case of a synchronous bilateral ductal carcinoma in situ (DCIS) which developed in a 26-year-old man with long-standing gynecomastia. He underwent bilateral subcutaneous mastectomy. Histology revealed bilateral pure DCIS. There was no identifiable causative factor for the development of bilateral DCIS, and there was no family history of the disease. No other treatment was required, and after 18 months there were no signs of local recurrence. This case highlights the importance of staying vigilant regarding the presence of malignancy in normally benign conditions. Liposuction has become a very useful technique for gynecomastia correction, however, there is a risk of dissemination of an unknown malignant tumor. In atypical cases, en bloc surgical excision should be performed.
Assuntos
Neoplasias da Mama Masculina , Carcinoma Intraductal não Infiltrante , Ginecomastia , Lipectomia , Mastectomia , Adulto , Neoplasias da Mama Masculina/cirurgia , Carcinoma Intraductal não Infiltrante/cirurgia , Ginecomastia/etiologia , Ginecomastia/cirurgia , Humanos , Masculino , Recidiva Local de NeoplasiaRESUMO
In this paper, we aim to focus on false positive results in the evaluation of thyroid aspirations, covering cystic, inflammatory, follicular and oncocytic lesions, papillary carcinoma, and medullary carcinoma of thyroid. The recently described entity noninvasive follicular thyroid neoplasm with papillary-like nuclear features is also discussed detailing the impact of its introduction on the sensitivity and specificity of thyroid FNA, as well as the use of molecular tests for diagnostics. Medicolegal issues in relation to current practice in English law are also described.
Assuntos
Biópsia por Agulha Fina , Doenças da Glândula Tireoide/patologia , Glândula Tireoide/patologia , Diagnóstico Diferencial , Reações Falso-Positivas , Humanos , Sensibilidade e EspecificidadeRESUMO
The structure of phycobiliproteins of the cyanobacterium Acaryochloris marina was investigated in buffer solution at physiological temperatures, i.e. under the same conditions applied in spectroscopic experiments, using small angle neutron scattering. The scattering data of intact phycobiliproteins in buffer solution containing phosphate can be well described using a cylindrical shape with a length of about 225Å and a diameter of approximately 100Å. This finding is qualitatively consistent with earlier electron microscopy studies reporting a rod-like shape of the phycobiliproteins with a length of about 250 (M. Chen et al., FEBS Letters 583, 2009, 2535) or 300Å (J. Marquart et al., FEBS Letters 410, 1997, 428). In contrast, phycobiliproteins dissolved in buffer lacking phosphate revealed a splitting of the rods into cylindrical subunits with a height of 28Å only, but also a pronounced sample aggregation. Complementary small angle neutron and X-ray scattering experiments on phycocyanin suggest that the cylindrical subunits may represent either trimeric phycocyanin or trimeric allophycocyanin. Our findings are in agreement with the assumption that a phycobiliprotein rod with a total height of about 225Å can accommodate seven trimeric phycocyanin subunits and one trimeric allophycocyanin subunit, each of which having a height of about 28Å. The structural information obtained by small angle neutron and X-ray scattering can be used to interpret variations in the low-energy region of the 4.5K absorption spectra of phycobiliproteins dissolved in buffer solutions containing and lacking phosphate, respectively.
Assuntos
Cianobactérias/química , Transferência de Energia , Espalhamento a Baixo Ângulo , Difração de Nêutrons , Ficobiliproteínas/química , Difração de Raios XRESUMO
OBJECTIVE: BRAFV600E represents the most common diagnostic marker in papillary thyroid carcinoma (PTC). A few papers have demonstrated the correlation between BRAFV600E and specific morphological findings on PTCs in the adult population. This is the first reported series investigating cytological morphological parameters in paediatric thyroid carcinoma. METHODS: One hundred and nineteen paediatric samples (56 male and 63 female patients), diagnosed in the period between April 2013 and July 2015, were enrolled in the study. Fifteen patients with inadequate results were excluded. Cytological cases were processed with liquid-based cytology (LBC). BRAFV600E and immunocytochemistry for the VE1 antibody were performed on LBC. RESULTS: The diagnostic series included 10 mutated and 94 wild-type (WT) cases. Twenty two percent surgical samples showed 96% cytohistological concordance. The morphological analysis revealed plump cells (abundant eosinophilic cytoplasm and PTC nuclei) in all 10 mutated cases with only four cases showing a focal (less than 20% of the cells) plump component. None of the WT showed plump cells. A sickle nuclear shape was seen only in the mutated cases. VE1 yielded 100% positivity on mutated cases with three cytohistological discrepancies. CONCLUSIONS: The BRAFV600E mutation is also seen in paediatric cytology and the morphological features showed a high accuracy as both predictive mutational parameters and a helpful aid in management mainly of the aggressive BRAFV600E mutated carcinomas.
Assuntos
Carcinoma/diagnóstico , Citodiagnóstico , Proteínas Proto-Oncogênicas B-raf/genética , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/diagnóstico , Adolescente , Carcinoma/genética , Carcinoma/patologia , Carcinoma Papilar , Criança , Análise Mutacional de DNA , Feminino , Humanos , Imuno-Histoquímica , Masculino , Mutação , Câncer Papilífero da Tireoide , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologia , Nódulo da Glândula Tireoide/patologiaRESUMO
Accidents in which a person is run over are often associated with multiple serious injuries. Immediate bleeding control is crucial. Pressure and shear stress at the borders of subcutaneous tissue to the muscle fascia can cause hypoperfusion and the emergence of blood-filled cavities that are associated with a high risk of infection and necrosis, a so-called Morel-Lavallée lesion. Insufficient therapy can lead to local complications and furthermore to live-threatening sepsis.
Assuntos
Traumatismo Múltiplo/terapia , Ferimentos e Lesões/terapia , Acidentes de Trânsito , Adolescente , Desbridamento , Hemorragia/etiologia , Hemorragia/terapia , Humanos , Masculino , Traumatismo Múltiplo/etiologia , Traumatismo Múltiplo/cirurgia , Necrose , Manejo da Dor , Sepse/etiologia , Sepse/terapia , Síndrome , Ferimentos e Lesões/complicaçõesRESUMO
Orange carotenoid protein (OCP) is a water-soluble photoactive protein responsible for a photoprotective mechanism of nonphotochemical quenching in cyanobacteria. Under blue-green illumination, OCP converts from the stable orange into the signaling red quenching form; however, the latter form could also be obtained by chemical activation with high concentrations of sodium thiocyanate (NaSCN) or point mutations. In this work, we show that a single replacement of tryptophan-288, normally involved in protein-chromophore interactions, by alanine, results in formation of a new protein form, hereinafter referred to as purple carotenoid protein (PCP). Comparison of resonance Raman spectra of the native photoactivated red form, chemically activated OCP, and PCP reveals that carotenoid conformation is sensitive to the structure of the C-domain, implicating that the chromophore retains some interactions with this part of the protein in the active red form. Combination of differential scanning fluorimetry and picosecond time-resolved fluorescence anisotropy measurements allowed us to compare the stability of different OCP forms and to estimate relative differences in protein rotation rates. These results were corroborated by hydrodynamic analysis of proteins by dynamic light scattering and analytical size-exclusion chromatography, indicating that the light-induced conversion of the protein is accompanied by a significant increase in its size. On the whole, our data support the idea that the red form of OCP is a molten globule-like protein in which, however, interactions between the carotenoid and the C-terminal domain are preserved.
Assuntos
Proteínas de Bactérias/fisiologia , Proteínas de Bactérias/química , Proteínas de Bactérias/isolamento & purificação , Cromatografia em Gel , Clonagem Molecular , Cianobactérias/fisiologia , Fluorescência , Polarização de Fluorescência , Fluorometria , Análise Espectral Raman , Synechocystis/fisiologiaRESUMO
It was hypothesized that the Malabar grouper Ephinephelus malabaricus larvae have developed search patterns adapted to the distribution of their prey to maximise their net energy intake per unit time. Analysis of the swimming behaviour of E. malabaricus larvae in both the presence and absence of Artemia sp. nauplii is presented to test this hypothesis. A method derived from turbulence studies (the moment function of the displacements) was used to characterize the behaviour. The results revealed that larval swimming pattern was multifractal (intermittent and long-range-correlated) and isotropic (i.e. uniform in all directions) in the presence of prey, but multifractal and anisotropic (i.e. more frequent long displacement on the vertical axis) in the absence of prey. It is suggested that the search behaviour observed in the absence of prey is an adaptive response to prey distribution pattern, which is often characterised by multifractality and anisotropy (i.e. larger patches on the horizontal axes). In the presence of prey, E. malabaricus shifted to intensive search behaviour. Other possible contributors to the observed patterns are discussed. It is concluded that multifractality and anisotropy of swimming patterns observed in the experiment are mainly explained in an optimal foraging theory framework.
Assuntos
Comportamento Alimentar , Perciformes/fisiologia , Natação , Adaptação Fisiológica , Animais , Anisotropia , Ingestão de Energia , Larva/fisiologia , Comportamento Predatório/fisiologiaRESUMO
As high-intensity solar radiation can lead to extensive damage of the photosynthetic apparatus, cyanobacteria have developed various protection mechanisms to reduce the effective excitation energy transfer (EET) from the antenna complexes to the reaction center. One of them is non-photochemical quenching (NPQ) of the phycobilisome (PB) fluorescence. In Synechocystis sp. PCC6803 this role is carried by the orange carotenoid protein (OCP), which reacts to high-intensity light by a series of conformational changes, enabling the binding of OCP to the PBs reducing the flow of energy into the photosystems. In this paper the mechanisms of energy migration in two mutant PB complexes of Synechocystis sp. were investigated and compared. The mutant CK is lacking phycocyanin in the PBs while the mutant ΔPSI/PSII does not contain both photosystems. Fluorescence decay spectra with picosecond time resolution were registered using a single photon counting technique. The studies were performed in a wide range of temperatures - from 4 to 300 K. The time course of NPQ and fluorescence recovery in darkness was studied at room temperature using both steady-state and time-resolved fluorescence measurements. The OCP induced NPQ has been shown to be due to EET from PB cores to the red form of OCP under photon flux densities up to 1000 µmolphotonsm⻲s⻹. The gradual changes of the energy transfer rate from allophycocyanin to OCP were observed during the irradiation of the sample with blue light and consequent adaptation to darkness. This fact was interpreted as the revelation of intermolecular interaction between OCP and PB binding site. At low temperatures a significantly enhanced EET from allophycocyanin to terminal emitters has been shown, due to the decreased back transfer from terminal emitter to APC. The activation of OCP not only leads to fluorescence quenching, but also affects the rate constants of energy transfer as shown by model based analysis of the decay associated spectra. The results indicate that the ability of OCP to quench the fluorescence is strongly temperature dependent. This article is part of a special issue entitled: photosynthesis research for sustainability: keys to produce clean energy.
Assuntos
Fluorometria/métodos , Ficobilissomas/química , Synechocystis/metabolismo , Transferência de Energia , Fluorescência , Conformação ProteicaRESUMO
BACKGROUND: Using surrogate end points for overall survival, such as disease-free survival, is increasingly common in randomized controlled trials. However, the definitions of several of these time-to-event (TTE) end points are imprecisely which limits interpretation and cross-trial comparisons. The estimation of treatment effects may be directly affected by the definitions of end points. The DATECAN initiative (Definition for the Assessment of Time-to-event Endpoints in CANcer trials) aims to provide recommendations for definitions of TTE end points. We report guidelines for randomized cancer clinical trials (RCTs) in breast cancer. PATIENTS AND METHODS: A literature review was carried out to identify TTE end points (primary or secondary) reported in publications of randomized trials or guidelines. An international multidisciplinary panel of experts proposed recommendations for the definitions of these end points based on a validated consensus method that formalize the degree of agreement among experts. RESULTS: Recommended guidelines for the definitions of TTE end points commonly used in RCTs for breast cancer are provided for non-metastatic and metastatic settings. CONCLUSION: The use of standardized definitions should facilitate comparisons of trial results and improve the quality of trial design and reporting. These guidelines could be of particular interest to those involved in the design, conducting, reporting, or assessment of RCT.
Assuntos
Neoplasias da Mama/terapia , Determinação de Ponto Final/normas , Ensaios Clínicos Controlados Aleatórios como Assunto/normas , Projetos de Pesquisa/normas , Terminologia como Assunto , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/mortalidade , Consenso , Técnica Delphi , Progressão da Doença , Intervalo Livre de Doença , Determinação de Ponto Final/classificação , Feminino , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto/classificação , Fatores de Tempo , Falha de TratamentoRESUMO
The time courses of the photosystem II (PSII) redox states were analyzed with a model scheme supposing a fraction of 11-25 % semiquinone (with reduced [Formula: see text]) RCs in the dark. Patterns of single flash-induced transient fluorescence yield (SFITFY) measured for leaves (spinach and Arabidopsis (A.) thaliana) and the thermophilic alga Chlorella (C.) pyrenoidosa Chick (Steffen et al. Biochemistry 44:3123-3132, 2005; Belyaeva et al. Photosynth Res 98:105-119, 2008, Plant Physiol Biochem 77:49-59, 2014) were fitted with the PSII model. The simulations show that at high-light conditions the flash generated triplet carotenoid (3)Car(t) population is the main NPQ regulator decaying in the time interval of 6-8 µs. So the SFITFY increase up to the maximum level [Formula: see text]/F 0 (at ~50 µs) depends mainly on the flash energy. Transient electron redistributions on the RC redox cofactors were displayed to explain the SFITFY measured by weak light pulses during the PSII relaxation by electron transfer (ET) steps and coupled proton transfer on both the donor and the acceptor side of the PSII. The contribution of non-radiative charge recombination was taken into account. Analytical expressions for the laser flash, the (3)Car(t) decay and the work of the water-oxidizing complex (WOC) were used to improve the modeled P680(+) reduction by YZ in the state S 1 of the WOC. All parameter values were compared between spinach, A. thaliana leaves and C. pyrenoidosa alga cells and at different laser flash energies. ET from [Formula: see text] slower in alga as compared to leaf samples was elucidated by the dynamics of [Formula: see text] fractions to fit SFITFY data. Low membrane energization after the 10 ns single turnover flash was modeled: the ∆Ψ(t) amplitude (20 mV) is found to be about 5-fold smaller than under the continuous light induction; the time-independent lumen pHL, stroma pHS are fitted close to dark estimates. Depending on the flash energy used at 1.4, 4, 100 % the pHS in stroma is fitted to 7.3, 7.4, and 7.7, respectively. The biggest ∆pH difference between stroma and lumen was found to be 1.2, thus pH- dependent NPQ was not considered.
Assuntos
Arabidopsis/metabolismo , Chlorella/metabolismo , Transporte de Elétrons/efeitos da radiação , Complexo de Proteína do Fotossistema II/metabolismo , Spinacia oleracea/metabolismo , Animais , Arabidopsis/efeitos da radiação , Chlorella/efeitos da radiação , Elétrons , Fluorescência , Lasers , Luz , Simulação de Dinâmica Molecular , Oxirredução , Complexo de Proteína do Fotossistema II/efeitos da radiação , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação , Prótons , Espectrometria de Fluorescência , Spinacia oleracea/efeitos da radiaçãoRESUMO
We report findings of strong anomalies in both mutual inductance and inelastic Raman spectroscopy measurements of single-unit-cell FeSe film grown on Nb-doped SrTiO3, which occur near the temperature where the superconductinglike energy gap opens. Analysis suggests that the anomaly is associated with a broadened ferroelectric transition in a thin layer near the FeSe/SrTiO3 interface. The coincidence of the ferroelectric transition and gap-opening temperatures adds credence to the central role played by the film-substrate interaction on the strong Cooper pairing in this system. We discuss scenarios that could explain such a coincidence.
RESUMO
Despite significant advances in diagnosis, surgical techniques, general patient care, and local and systemic adjuvant therapies, metastatic disease remains the most critical condition limiting the survival of patients with breast cancer. Therefore, the development of effective treatment against late-arising metastasis has become the centre of clinical attention and is one of the current challenges in cancer research. A deeper understanding of the metastatic cascade is fundamental, and the need for repetitive tumour assessments for the evaluation of tumour evolution is a relatively new practice in routine medical care. As such, fine needle aspiration cytology (FNAC) is ideally placed to monitor biological changes in metastasis that may affect treatment and response. As FNAC is a minimally invasive method, it can be performed repeatedly with relatively little trauma, and selective ancillary tests can be applied to FNAC specimens, including for tumour whose primary nature is known. Herein, we review how the linear and parallel models explain metastatic dissemination, thus influencing therapeutic and clinical decisions, and how cytology, together with immunocytochemistry and molecular analysis, can be a tool for routine clinical practice and clinical trials aimed at metastatic disease with a special emphasis on breast cancer.
Assuntos
Biópsia por Agulha Fina , Neoplasias da Mama/diagnóstico , Citodiagnóstico , Segunda Neoplasia Primária/diagnóstico , Neoplasias da Mama/patologia , Feminino , Humanos , Metástase Neoplásica , Segunda Neoplasia Primária/patologiaRESUMO
OBJECTIVES: To discuss the role and training of cytotechnologists (CTs) in Europe, to identify areas of good practice and to provide an informed opinion to those providing guidelines for training and practice in Europe. METHODS: All members of the Editorial Advisory Board of Cytopathology were invited to take part in a 'discussion forum' for which six topics were circulated in advance concerning the roles of CTs with regard to: (1) pre-screening slides; (2) 'signing out' reports; (3) carrying out ancillary techniques; (4) supervising laboratory staff; (5) taking part in rapid on-site evaluation (ROSE) of fine needle aspirates (FNAs); and (6) whether CTs were trained specifically in cytopathology or in general histopathology. Notes of the meeting were circulated by email and a final report was agreed by 22 participants from 17 predominantly European countries. RESULTS: Training for CTs throughout Europe was variable, especially for non-gynaecological cytology, which was inconsistent with the range of activities required. The participants recommended graduate entry, preliminary training in general laboratory technology, and subsequent training to take account of the probability and, in some centres, the reality of primary cervical cancer screening changing from cytology to human papillomavirus (HPV) testing. They further recommended that CTs should perform HPV tests and take part in ROSE for FNAs, and they supported the European Federation of Cytology Societies developing guidelines for training and practice. CONCLUSION: With CT training added to a university-based education in laboratory or biomedical science, a career in cytotechnology should be an attractive option involving a diverse range of laboratory and clinically based activities.
Assuntos
Citodiagnóstico/normas , Educação/normas , Pessoal de Laboratório Médico/normas , Citodiagnóstico/métodos , Educação/métodos , Europa (Continente) , HumanosRESUMO
INTRODUCTION: Oncologic esophagectomy is a two-cavity procedure with considerable morbidity and mortality. Complex anatomy and the proximity to major vessels constitute a risk for massive intraoperative hemorrhage. Currently, there is no conclusive consensus on the ideal anesthesiologic countermeasure in case of such immense blood loss. The objective of this work was to identify the most promising anesthesiologic management in case of intraoperative hemorrhage with regards to tissue perfusion of the gastric conduit during esophagectomy using hyperspectral imaging (HSI). MATERIAL AND METHODS: An established live porcine model (n=32) for esophagectomy was used with gastric conduit formation and simulation of a linear stapled side-to-side esophagogastrostomy. After a standardized procedure of controlled blood loss of about 1 L per pig, the four experimental groups (n=8 each) differed in anesthesiologic intervention i.e. (I) permissive hypotension, (II) catecholamine therapy using noradrenaline, (III) crystalloid volume supplementation and (IV) combined crystalloid volume supplementation with noradrenaline therapy. HSI tissue oxygenation (StO2) of the gastric conduit was evaluated and correlated with systemic perfusion parameters. Measurements were conducted before (T0) and after (T1) laparotomy, after hemorrhage (T2) and 60 minutes (T3) and 120 minutes (T4) after anesthesiologic intervention. RESULTS: StO2 values of the gastric conduit showed significantly different results between the four experimental groups with 63.3% (±7.6%) after permissive hypotension (I), 45.9% (±6.4%) after catecholamine therapy (II), 70.5% (±6.1%) after crystalloid volume supplementation (III) and 69.0% (±3.7%) after combined therapy (IV). StO2 values correlated strongly with systemic lactate values (r=-0.67; CI -0.77 to -0.54), which is an established prognostic factor. CONCLUSION: Crystalloid volume supplementation (III) yields the highest StO2 values and lowest systemic lactate values and therefore appears to be the superior primary treatment strategy after hemorrhage during esophagectomy with regards to microcirculatory tissue oxygenation of the gastric conduit.
RESUMO
The present work describes results obtained on hybrid systems formed in aqueous buffer solution by self-assembly of different CdSe quantum dots (QDs) surrounded by a ZnS shell and functionalized by covering the surface with anionic and cationic groups and various isolated pigment-protein complexes from the light-harvesting antennae of photosynthetic organisms (light-harvesting complexes 1 and 2 (LH1 and LH2, respectively) from purple bacteria, phycobiliproteins (PBPs) from cyanobacteria and the rod-shaped PBP from the cyanobacterium Acaryochloris marina). Excitation energy transfer (EET) from QDs to PBP rods was found to take place with varying and highly temperature-dependent efficiencies of up to 90%. Experiments performed at room temperature on hybrid systems with different QDs show that no straightforward correlation exists between the efficiency of EET and the parameter J/(R(12)(6)) given by the theory of Förster resonance energy transfer (FRET), where J is the overlap integral of the normalized QD emission and PBP absorption and R(12) the distance between the transition dipole moments of donor and acceptor. The results show that the hybrid systems cannot be described as randomly orientated aggregates consisting of QDs and photosynthetic pigment-protein complexes. Specific structural parameters are inferred to play an essential role. The mode of binding and coupling seems to change with the size of QDs and with temperature. Efficient EET and fluorescence enhancement of the acceptor was observed at particular stoichiometric ratios between QDs and trimeric phycoerythrin (PE). At higher concentrations of PE, a quenching of its fluorescence is observed in the presence of QDs. This effect is explained by the existence of additional quenching channels in aggregates formed within hybrid systems. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial.