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As known "ecosystem engineers", beavers influence river hydrology, geomorphology, biochemistry, and biological assemblages. However, there is a lack of research regarding the effects of beaver activities on freshwater meiofauna. In this study, we investigated the taxonomic and functional composition of the benthic copepod assemblage of a segment of the Tiber River (Italy) where a beaver dam, created about 7 weeks before our survey, had formed a semi-lentic habitat upstream and a lotic habitat downstream of the dam. We also analyzed the copepod assemblage before and after a flood event that destroyed the beaver dam, providing a unique opportunity to observe changes in a naturally reversing scenario. Our analyses revealed that, while the taxonomic composition and functional traits of the copepod assemblage remained largely unchanged across the recently formed semi-lentic and lotic habitats, substantial differences were evident between the dammed and undammed states. The dammed state showed lower copepod abundances, biomass, and functionality than the undammed one. These results highlight the role of beaver dams in changing the composition and functionality of meiofaunal assemblages offering insights into the dynamic interactions within aquatic ecosystems.
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Copépodes , Ecossistema , Animais , Roedores , Rios , BiomassaRESUMO
PURPOSE: The standard recall period for the patient-reported outcomes version of the common terminology criteria for adverse events (PRO-CTCAE®) is the past 7 days, but there are contexts where a 24-hour recall may be desirable. The purpose of this analysis was to investigate the reliability and validity of a subset of PRO-CTCAE items captured using a 24-hour recall. METHODS: 27 PRO-CTCAE items representing 14 symptomatic adverse events (AEs) were collected using both a 24-hour recall (24 h) and the standard 7 day recall (7d) in a sample of patients receiving active cancer treatment (n = 113). Using data captured with a PRO-CTCAE-24h on days 6 and 7, and 20 and 21, we computed intra-class correlation coefficients (ICC); an ICC ≥ 0.70 was interpreted as demonstrating high test-retest reliability. Correlations between PRO-CTCAE-24h items on day 7 and conceptually relevant EORTC QLQ-C30 domains were examined. In responsiveness analysis, patients were deemed changed if they had a one-point or greater change in the corresponding PRO-CTCAE-7d item (from week 0 to week 1). RESULTS: PRO-CTCAE-24h captured on two consecutive days demonstrated that 21 of 27 items (78%) had ICCs ≥ 0.70 (day 6/7 median ICC 0.76), (day 20/21 median ICC 0.84). Median correlation between attributes within a common AE was 0.75, and the median correlation between conceptually relevant EORTC QLQ-C30 domains and PRO-CTCAE-24 h items captured on day 7 was 0.44. In the analysis of responsiveness to change, the median standardized response mean (SRM) for patients with improvement was - 0.52 and that for patients with worsening was 0.71. CONCLUSION: A 24-hour recall period for PRO-CTCAE items has acceptable measurement properties and can inform day-to-day variations in symptomatic AEs when daily PRO-CTCAE administration is implemented in a clinical trial.
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Antineoplásicos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Neoplasias , Humanos , Antineoplásicos/uso terapêutico , Reprodutibilidade dos Testes , Sistemas de Notificação de Reações Adversas a Medicamentos , Qualidade de Vida/psicologia , Neoplasias/terapia , Medidas de Resultados Relatados pelo Paciente , Inquéritos e QuestionáriosRESUMO
CASE REPORT: A 14-year-old girl presented with 1 cm large whitened lesion on the ventral surface of the tongue, appeared from 1 month. Past history showed congenital dyserythropoietic anemia type II. The lesion was excised and microscopic and immunohistochemical analyses were compatible with benign Abrikossoff tumor. Total body MRI was negative. After six months the patient presented a second tongue lesion and four months later another large painful lesion in the soft palate, with the same istological diagnosis. In addition, she had other multiple lesions: two apperead at pharyngeal level (not biopsied) that remain stable over time, and one at the pituitary gland. CONCLUSION: Granular cell tumors, with or without multiple lesions, are rare in children. About 50% of cases involve the head and neck region, with the tongue being the most affected site. Therapy is based on the surgical excision of the lesions; however some tumor forms, although their histological aspect of benignity, often have an important infiltrative power, making the therapeutic approach difficult, as in our case.
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Anemia Diseritropoética Congênita , Tumor de Células Granulares , Adolescente , Feminino , Tumor de Células Granulares/complicações , Tumor de Células Granulares/cirurgia , Humanos , Imageamento por Ressonância Magnética , Recidiva Local de NeoplasiaRESUMO
BACKGROUND: Impaired intestinal epithelial barrier is highly affected in inflammatory bowel disease. Transmembrane collagens connecting the epithelial cells to the extracellular matrix have an important role in epithelial cell homeostasis. Thus, we sought to determine whether the transmembrane type 23 collagen could serve as a surrogate marker for disease activity in patients with Crohn's disease and ulcerative colitis. METHODS: We developed an enzyme-linked immunosorbent assay to detect the ectodomain of type 23 collagen (PRO-C23) in serum, followed by evaluation of its levels in both acute and chronic dextran sulphate sodium colitis models in rats and human inflammatory bowel disease cohorts. Serum from 44 Crohn's disease and 29 ulcerative colitis patients with active and inactive disease was included. RESULTS: In the acute and chronic dextran sulphate sodium-induced rat colitis model, the PRO-C23 serum levels were significantly increased after colitis and returned to normal levels after disease remission. Serum levels of PRO-C23 were elevated in Crohn's disease (p < 0.05) and ulcerative colitis (p < 0.001) patients with active disease compared to healthy donors. PRO-C23 differentiated healthy donors from ulcerative colitis (area under the curve [AUC]: 0.81, p = 0.0009) and Crohn's disease (AUC: 0.70, p = 0.0124). PRO-C23 differentiated ulcerative colitis patients with active disease from those in remission (AUC: 0.75, p = 0.0219) and Crohn's disease patients with active disease from those in remission (AUC: 0.68, p = 0.05). CONCLUSION: PRO-C23 was elevated in rats with active colitis, and inflammatory bowel disease patients with active disease. Therefore, PRO-C23 may be used as a surrogate marker for monitoring disease activity in ulcerative colitis and Crohn's disease.
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Colite Ulcerativa/diagnóstico , Colágeno/sangue , Doença de Crohn/diagnóstico , Mucosa Intestinal/metabolismo , Adulto , Animais , Anticorpos/sangue , Biomarcadores/sangue , Colite Ulcerativa/metabolismo , Colágeno/imunologia , Doença de Crohn/metabolismo , Sulfato de Dextrana/sangue , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ratos Sprague-DawleyRESUMO
The proof of concept of a new device, capable of determining in a few seconds the energy of clinical proton beams by measuring the time of flight (ToF) of protons, is presented. The prototype consists of two thin ultra fast silicon detector (UFSD) pads, aligned along the beam direction in a telescope configuration and readout by a digitizer. The method developed for extracting the energy at the isocenter from the measured ToF, validated by Monte Carlo simulations, and the procedure used to calibrate the system are also presented and discussed in detail. The prototype was tested at the Centro Nazionale di Adroterapia Oncologica (CNAO, Pavia, Italy), at several beam energies, covering the entire clinical range, and using different distances between the sensors. The measured beam energies were benchmarked against the nominal CNAO energy values, obtained during the commissioning of the centre from the measured ranges in water. Deviations of few hundreds of keV have been achieved for all considered proton beam energies for distances between the two sensors larger than 60 cm, indicating a sensitivity to the corresponding beam range in water smaller than the clinical tolerance of 1 mm. Moreover, few seconds of irradiation were necessary to collect the required statistics. These preliminary results indicate that a telescope of UFSDs could achieve in a short time the accuracy required for the clinical application and therefore encourage further investigations towards the improvement and the optimization of the present prototype.
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Terapia com Prótons/métodos , Estudos de Viabilidade , Humanos , Método de Monte Carlo , Terapia com Prótons/instrumentação , Planejamento da Radioterapia Assistida por ComputadorRESUMO
BACKGROUND AND PURPOSE: Perfusion MR imaging measures of relative CBV can distinguish recurrent tumor from posttreatment radiation effects in high-grade gliomas. Currently, relative CBV measurement requires normalization based on user-defined reference tissues. A recently proposed method of relative CBV standardization eliminates the need for user input. This study compares the predictive performance of relative CBV standardization against relative CBV normalization for quantifying recurrent tumor burden in high-grade gliomas relative to posttreatment radiation effects. MATERIALS AND METHODS: We recruited 38 previously treated patients with high-grade gliomas (World Health Organization grades III or IV) undergoing surgical re-resection for new contrast-enhancing lesions concerning for recurrent tumor versus posttreatment radiation effects. We recovered 112 image-localized biopsies and quantified the percentage of histologic tumor content versus posttreatment radiation effects for each sample. We measured spatially matched normalized and standardized relative CBV metrics (mean, median) and fractional tumor burden for each biopsy. We compared relative CBV performance to predict tumor content, including the Pearson correlation (r), against histologic tumor content (0%-100%) and the receiver operating characteristic area under the curve for predicting high-versus-low tumor content using binary histologic cutoffs (≥50%; ≥80% tumor). RESULTS: Across relative CBV metrics, fractional tumor burden showed the highest correlations with tumor content (0%-100%) for normalized (r = 0.63, P < .001) and standardized (r = 0.66, P < .001) values. With binary cutoffs (ie, ≥50%; ≥80% tumor), predictive accuracies were similar for both standardized and normalized metrics and across relative CBV metrics. Median relative CBV achieved the highest area under the curve (normalized = 0.87, standardized = 0.86) for predicting ≥50% tumor, while fractional tumor burden achieved the highest area under the curve (normalized = 0.77, standardized = 0.80) for predicting ≥80% tumor. CONCLUSIONS: Standardization of relative CBV achieves similar performance compared with normalized relative CBV and offers an important step toward workflow optimization and consensus methodology.
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Neoplasias Encefálicas/diagnóstico por imagem , Glioma/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/normas , Imageamento por Ressonância Magnética/normas , Neuroimagem/métodos , Adulto , Idoso , Neoplasias Encefálicas/patologia , Feminino , Glioma/patologia , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Lesões por Radiação/diagnóstico por imagem , Lesões por Radiação/patologia , Carga TumoralRESUMO
BACKGROUND: Primary sclerosing cholangitis is a progressive liver disease with a remarkably variable course. Biomarkers of disease activity or prognostic models predicting outcome at an individual level are currently not established. AIM: To evaluate the prognostic utility of four biomarkers of basement membrane and interstitial extracellular matrix remodeling in patients with primary sclerosing cholangitis. METHODS: Serum samples were available from 138 large-duct primary sclerosing cholangitis patients (of which 102 [74%] with IBD) recruited 2008-2012 and 52 ulcerative colitis patients (controls). The median follow-up time was 2.2 (range 0-4.3) years. Specific biomarkers of type III and V collagen formation (PRO-C3 and PRO-C5, respectively) and type III and IV collagen degradation (C3M and C4M, respectively) were assessed. The Enhanced Liver Fibrosis test, including procollagen type III N-terminal peptide, tissue inhibitor of metalloproteinase-1 and hyaluronic acid was assessed for comparison. RESULTS: All markers were elevated in primary sclerosing cholangitis compared to ulcerative colitis patients (P < 0.001). PRO-C3 showed the largest difference between the two groups with a threefold increase in primary sclerosing cholangitis compared to ulcerative colitis patients. Patients with high baseline serum levels of all markers, except C3M, had shorter survival compared to patients with low baseline serum levels (P < 0.001). Combining PRO-C3 and PRO-C5 the odds ratio for predicting transplant-free survival was 47 compared to the Enhanced Liver Fibrosis test's odds ratio of 11. CONCLUSIONS: Extracellular matrix remodeling is elevated in primary sclerosing cholangitis patients compared to ulcerative colitis patients. Furthermore, the interstitial matrix marker PRO-C3 was identified as a potent prognostic marker and an independent predictor of transplant-free survival in primary sclerosing cholangitis.
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Biomarcadores/sangue , Colangite Esclerosante/diagnóstico , Colangite Esclerosante/mortalidade , Matriz Extracelular/metabolismo , Adolescente , Adulto , Idoso , Colangite Esclerosante/sangue , Colangite Esclerosante/terapia , Colite Ulcerativa/sangue , Colite Ulcerativa/diagnóstico , Colite Ulcerativa/mortalidade , Progressão da Doença , Matriz Extracelular/patologia , Feminino , Humanos , Ácido Hialurônico/sangue , Cirrose Hepática/sangue , Cirrose Hepática/diagnóstico , Cirrose Hepática/mortalidade , Cirrose Hepática/terapia , Transplante de Fígado , Masculino , Pessoa de Meia-Idade , Fragmentos de Peptídeos/sangue , Valor Preditivo dos Testes , Pró-Colágeno/sangue , Prognóstico , Análise de Sobrevida , Inibidor Tecidual de Metaloproteinase-1/sangue , Adulto JovemRESUMO
We evaluated stereotactic volume modulated arc radiotherapy (VMAT) for canine gliomas, alone (radiotherapy [RT]) and in combination with temozolomide (RT + TMZ), compared with palliation. Overall and disease-specific survival times were estimated. Thirty dogs were palliated, 22 dogs were treated with RT and 20 with RT + TMZ. Complete and partial responses were observed in 63.2% and 90.9% of patients in the RT and RT + TMZ arms, respectively, that were alive at 1 year. Median survival in the palliation arm was 94 days (95% conformity index [CI] 87÷101). Median survivals of the RT arm (383 days, 95% CI 276÷490) and RT+TMZ arm (420 days, 95% CI 280÷560) were not significantly different (P = .61). Positive correlation with survival was found both for the ratio between target and brain (relative) volume of the tumour of <5% (P = .013) and for a clinical presentation with normal mentation (P = .032). VMAT is feasible and effective for canine brain gliomas. Combining this therapy with TMZ did not elicit any additional improvement in survival time.
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Antineoplásicos Alquilantes/uso terapêutico , Neoplasias Encefálicas/veterinária , Dacarbazina/análogos & derivados , Doenças do Cão/radioterapia , Glioma/veterinária , Radiocirurgia/veterinária , Animais , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/terapia , Terapia Combinada/veterinária , Dacarbazina/uso terapêutico , Doenças do Cão/tratamento farmacológico , Doenças do Cão/mortalidade , Doenças do Cão/terapia , Cães , Feminino , Glioma/tratamento farmacológico , Glioma/radioterapia , Glioma/terapia , Masculino , Radiocirurgia/métodos , Análise de Sobrevida , TemozolomidaRESUMO
BACKGROUND: Randomized controlled trials (RCTs) involving surgical procedures are challenging for recruitment and infrequent in the specialty of bariatrics. The pilot phase of the By-Band-Sleeve study (gastric bypass versus gastric band versus sleeve gastrectomy) provided the opportunity for an investigation of recruitment using a qualitative research integrated in trials (QuinteT) recruitment intervention (QRI). PATIENTS/METHODS: The QRI investigated recruitment in two centers in the pilot phase comparing bypass and banding, through the analysis of 12 in-depth staff interviews, 84 audio recordings of patient consultations, 19 non-participant observations of consultations and patient screening data. QRI findings were developed into a plan of action and fed back to centers to improve information provision and recruitment organization. RESULTS: Recruitment proved to be extremely difficult with only two patients recruited during the first 2 months. The pivotal issue in Center A was that an effective and established clinical service could not easily adapt to the needs of the RCT. There was little scope to present RCT details or ensure efficient eligibility assessment, and recruiters struggled to convey equipoise. Following presentation of QRI findings, recruitment in Center A increased from 9% in the first 2 months (2/22) to 40% (26/65) in the 4 months thereafter. Center B, commencing recruitment 3 months after Center A, learnt from the emerging issues in Center A and set up a special clinic for trial recruitment. The trial successfully completed pilot recruitment and progressed to the main phase across 11 centers. CONCLUSIONS: The QRI identified key issues that enabled the integration of the trial into the clinical setting. This contributed to successful recruitment in the By-Band-Sleeve trial-currently the largest in bariatric practice-and offers opportunities to optimize recruitment in other trials in bariatrics.
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Derivação Gástrica , Gastroplastia , Obesidade Mórbida/cirurgia , Seleção de Pacientes , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Humanos , Projetos Piloto , Pesquisa QualitativaRESUMO
BACKGROUND: Recruitment into surgical RCTs can be threatened if new interventions available outside the trial compete with those being evaluated. Adapting the trial to include the new intervention may overcome this issue, yet this is not often done in surgery. This paper describes the challenges, rationale and methods for adapting an RCT to include a new intervention. METHODS: The By-Band study was designed in the UK in 2009-2010 to compare the effectiveness of laparoscopic adjustable gastric band and Roux-en-Y gastric bypass for severe obesity. It contained a pilot phase to establish whether recruitment was possible, and the grant proposal specified that an adaptation to include sleeve gastrectomy would be considered if practice changed and recruitment was successful. Information on changing obesity surgery practice, updated evidence and expert opinion about trial design were used to inform the adaptation. RESULTS: The pilot phase recruited over 13 months in 2013-2014 and randomized 80 patients (79 anticipated). During this time, major changes in obesity practice in the UK were observed, with gastric band reducing from 32·6 to 15·8 per cent and sleeve gastrectomy increasing from 9·0 to 28·1 per cent. The evidence base had not changed markedly. The British Obesity and Metabolic Surgery Society and study oversight committees supported an adaptation to include sleeve gastrectomy, and a proposal to do so was approved by the funder. CONCLUSION: Adaptation of a two-group surgical RCT can allow evaluation of a third procedure and maintain relevance of the RCT to practice. It also optimizes the use of existing trial infrastructure to answer an additional important research question. Registration number: ISRCTN00786323 (http://www.isrctn.com/).
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Derivação Gástrica/métodos , Gastroplastia/métodos , Obesidade Mórbida/cirurgia , Ensaios Clínicos Controlados Aleatórios como Assunto/métodos , Atenção à Saúde/métodos , Derivação Gástrica/estatística & dados numéricos , Gastroplastia/estatística & dados numéricos , Humanos , Seleção de Pacientes , Projetos Piloto , Padrões de Prática Médica/tendênciasRESUMO
Mott insulators are "unsuccessful metals" in which Coulomb repulsion prevents charge conduction despite a metal-like concentration of conduction electrons. The possibility to unlock the frozen carriers with an electric field offers tantalizing prospects of realizing new Mott-based microelectronic devices. Here we unveil how such unlocking happens in a simple model that shows the coexistence of a stable Mott insulator and a metastable metal. Considering a slab subject to a linear potential drop, we find, by means of the dynamical mean-field theory, that the electric breakdown of the Mott insulator occurs via a first-order insulator-to-metal transition characterized by an abrupt gap collapse in sharp contrast to the standard Zener breakdown. The switch on of conduction is due to the field-driven stabilization of the metastable metallic phase. Outside the region of insulator-metal coexistence, the electric breakdown occurs through a more conventional quantum tunneling across the Hubbard bands tilted by the field. Our findings rationalize recent experimental observations and may offer a guideline for future technological research.
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OBJECTIVES: To evaluate the feasibility and efficacy of hypofractionated stereotactic volumetric-modulated arc radiotherapy in treating canine adrenal tumours with vascular invasion. METHODS: A single-arm clinical study was performed. The dogs underwent total body computed tomography, brain and abdomen magnetic resonance imaging and endocrine assay. Adrenal masses were classified as cortisol-secreting adrenal tumour or non-secreting adrenal tumour. Radiotherapy treatments were delivered by hypofractionated stereotactic volumetric-modulated arc radiotherapy via a linear accelerator. The overall survival was estimated by the Kaplan-Meier method. The overall response and radio-toxicity effects were determined. RESULTS: Nine dogs were enrolled. Three dogs were affected by cortisol-secreting adrenal tumours and the remaining dogs had non-secreting adrenal tumours. The prescribed doses ranged from 30 to 45 Gy in three or five consecutive daily fractions. The median overall survival time was 1030 days, and the overall mean reduction of the diameter and volume were ~32 and 30% respectively. The endocrine profile normalised in two dogs with cortisol-secreting adrenal tumours. Radio-toxicities were mild and self-limiting. Seven deaths were recorded during the follow-up period and two dogs were censored. CLINICAL SIGNIFICANCE: Hypofractionated stereotactic volumetric-modulated arc radiotherapy should be considered as a feasible and effective therapeutic option for adrenal tumours with vascular invasion.
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Neoplasias do Córtex Suprarrenal/veterinária , Doenças do Cão/radioterapia , Radiocirurgia/veterinária , Neoplasias do Córtex Suprarrenal/patologia , Neoplasias do Córtex Suprarrenal/radioterapia , Animais , Doenças do Cão/patologia , Cães , Estudos de Viabilidade , Feminino , Seguimentos , Masculino , Invasividade Neoplásica , Estadiamento de Neoplasias/veterinária , Estudos ProspectivosRESUMO
Even though umbilical cord arteries are a common source of vascular smooth muscle cells, the lack of reliable marker profiles have not facilitated the isolation of human umbilical artery smooth muscle cells (HUASMC). For accurate characterization of HUASMC and cells in their environment, the expression of smooth muscle and mesenchymal markers was analyzed in umbilical cord tissue sections. The resulting marker profile was then used to evaluate the quality of HUASMC isolation and culture methods. HUASMC and perivascular-Wharton's jelly stromal cells (pv-WJSC) showed positive staining for α-smooth muscle actin (α-SMA), smooth muscle myosin heavy chain (SM-MHC), desmin, vimentin and CD90. Anti-CD10 stained only pv-WJSC. Consequently, HUASMC could be characterized as α-SMA+ , SM-MHC+ , CD10- cells, which are additionally negative for endothelial markers (CD31 and CD34). Enzymatic isolation provided primary HUASMC batches with 90-99 % purity, yet, under standard culture conditions, contaminant CD10+ cells rapidly constituted more than 80 % of the total cell population. Contamination was mainly due to the poor adhesion of HUASMC to cell culture plates, regardless of the different protein coatings (fibronectin, collagen I or gelatin). HUASMC showed strong attachment and long-term viability only in 3D matrices. The explant isolation method achieved cultures with only 13-40 % purity with considerable contamination by CD10+ cells. CD10+ cells showed spindle-like morphology and up-regulated expression of α-SMA and SM-MHC upon culture in smooth muscle differentiation medium. Considering the high contamination risk of HUASMC cultures by CD10+ neighboring cells and their phenotypic similarities, precise characterization is mandatory to avoid misleading results.
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Hemophilia remains a non-curative disease, and patients are constrained to undergo repeated injections of clotting factors. In contrast, the sustained production of endogenous factors VIII (FVIII) or IX (FIX) by the patient's own cells could represent a curative treatment. Gene therapy has thus provided new hope for these patients. However, the issues surrounding the durability of expression and immune responses against gene transfer vectors remain. Cell therapy, involving stem cells expanded in vitro, can provide de novo protein synthesis and, if implanted successfully, could induce a steady-state production of low quantities of factors, which may keep the patient above the level required to prevent spontaneous bleeding. Liver-derived stem cells are already being assessed in clinical trials for inborn errors of metabolism and, in view of their capacity to produce FVIII and FIX in cell culture, they are now also being considered for clinical application in hemophilia patients.
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Fator IX/biossíntese , Fator VIII/biossíntese , Terapia Genética/métodos , Hemofilia A/cirurgia , Hemorragia/prevenção & controle , Fígado/metabolismo , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , Animais , Vesículas Extracelulares/metabolismo , Fator IX/genética , Fator VIII/genética , Hemofilia A/sangue , Hemofilia A/diagnóstico , Hemofilia A/genética , Hemostasia , Humanos , Resultado do TratamentoRESUMO
PURPOSE: The better understanding of vertebral mechanical properties can help to improve the diagnosis of vertebral fractures. As the bone mechanical competence depends not only from bone mineral density (BMD) but also from bone quality, the goal of the present study was to investigate the anisotropic indentation moduli of the different sub-structures of the healthy human vertebral body and spondylophytes by means of microindentation. METHODS: Six human vertebral bodies and five osteophytes (spondylophytes) were collected and prepared for microindentation test. In particular, indentations were performed on bone structural units of the cortical shell (along axial, circumferential and radial directions), of the endplates (along the anterio-posterior and lateral directions), of the trabecular bone (along the axial and transverse directions) and of the spondylophytes (along the axial direction). A total of 3164 indentations down to a maximum depth of 2.5 µm were performed and the indentation modulus was computed for each measurement. RESULTS: The cortical shell showed an orthotropic behavior (indentation modulus, Ei, higher if measured along the axial direction, 14.6±2.8 GPa, compared to the circumferential one, 12.3±3.5 GPa, and radial one, 8.3±3.1 GPa). Moreover, the cortical endplates (similar Ei along the antero-posterior, 13.0±2.9 GPa, and along the lateral, 12.0±3.0 GPa, directions) and the trabecular bone (Ei= 13.7±3.4 GPa along the axial direction versus Ei=10.9±3.7 GPa along the transverse one) showed transversal isotropy behavior. Furthermore, the spondylophytes showed the lower mechanical properties measured along the axial direction (Ei=10.5±3.3 GPa). CONCLUSIONS: The original results presented in this study improve our understanding of vertebral biomechanics and can be helpful to define the material properties of the vertebral substructures in computational models such as FE analysis.
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Testes de Dureza/métodos , Vértebras Lombares/citologia , Vértebras Lombares/fisiologia , Osteófito/patologia , Osteófito/fisiopatologia , Suporte de Carga/fisiologia , Idoso , Idoso de 80 Anos ou mais , Anisotropia , Força Compressiva/fisiologia , Módulo de Elasticidade/fisiologia , Feminino , Dureza/fisiologia , Humanos , Técnicas In Vitro , Masculino , Estresse MecânicoRESUMO
Apis mellifera venom is one of the best characterized venoms among Hymenoptera, yet relatively little is known about venom belonging to other species in the genus Apis. Melittin, one of the most important bioactive peptides, has been isolated and characterized in A. mellifera, Apis cerana, Apis dorsata and Apis florea, while apamin has been only characterized in A. mellifera and A. cerana. At present, no information is available about the sequence of A. dorsata apamin. Moreover, while the antiseptic properties of melittin and MCD peptides are well documented, the antimicrobial activity of apamin has never been tested. In the present study, we isolated and characterized apamin from the venom of the giant honeybee A. dorsata. We tested the activity of apamin against bacteria and yeasts in a microbiological assay to gain a more complete understanding of the antimicrobial competence of the medium molecular weight venom fraction. We show that A. dorsata apamin toxin has the same primary sequence as apamin in A. mellifera and A. cerana, yet with a different C-terminal amidation. We did not find any antiseptic activity of apamin against any of the tested microorganisms. We discuss the evolutionary processes connected to the ecological context of venom use that drove the generation of Apis venom complexity.
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Anti-Infecciosos/farmacologia , Apamina/farmacologia , Abelhas/química , Animais , Abelhas/classificação , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Meliteno/isolamento & purificação , Meliteno/farmacologia , Peptídeos/isolamento & purificação , Peptídeos/farmacologia , Especificidade da Espécie , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
The emissions of heavy metals during incineration of Municipal Solid Waste (MSW) are a major issue to health and the environment. It is then necessary to well quantify these emissions in order to accomplish an adequate control and prevent the heavy metals from leaving the stacks. In this study the kinetic behavior of Cadmium during Fluidized Bed Incineration (FBI) of artificial MSW pellets, for bed temperatures ranging from 923 to 1073 K, was modeled. FLUENT 12.1.4 was used as the modeling framework for the simulations and implemented together with a complete set of user-defined functions (UDFs). The CFD model combines the combustion of a single solid waste particle with heavy metal (HM) vaporization from the burning particle, and it takes also into account both pyrolysis and volatiles' combustion. A kinetic rate law for the Cd release, derived from the CFD thermal analysis of the combusting particle, is proposed. The simulation results are compared with experimental data obtained in a lab-scale fluidized bed incinerator reported in literature, and with the predicted values from a particulate non-isothermal model, formerly developed by the authors. The comparison shows that the proposed CFD model represents very well the evolution of the HM release for the considered range of bed temperature.
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Poluentes Atmosféricos/química , Cádmio/química , Modelos Teóricos , Incineração , Cinética , VolatilizaçãoRESUMO
Five cereal (triticale, durum wheat, CPS wheat, feed barley, oats) and two oilseed (canola, mustard) straws were fractionated with pressurized low polarity water in a flow-through reactor at 165°C with a flow rate of 115mL/min and a solvent-to-solid ratio of 60mL/g. The conversion and extraction of the major carbohydrates and lignin from the reactor system during hydrothermal treatment was largely completed within the first 20-30min. Glucan content of all straws were enriched by the process. More than 90% of the xylan and nearly 50% of the lignin were extracted and there was no effect on yield due to crop species. However, there were differences in solid residue and liquid extract composition. Cereal crops yielded a residue richer in glucan and lower in lignin. Oilseed crop residues contained very low levels of ash. Xylo-oligosaccharides from oilseed crops contain more acetyl and uronic acid substituents.
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Carboidratos/biossíntese , Fracionamento Químico/métodos , Lignina/biossíntese , Plantas/química , Resíduos/análise , Avena/química , Brassica napus/química , Liofilização , Hordeum/química , Mostardeira/química , Pressão , Temperatura , Triticum/química , Água/químicaAssuntos
Adenocarcinoma/diagnóstico , Carcinoma de Células em Anel de Sinete/diagnóstico , Neoplasias do Colo/diagnóstico , Colonografia Tomográfica Computadorizada , Neoplasias Colorretais Hereditárias sem Polipose/patologia , Erros de Diagnóstico , Reações Falso-Negativas , Feminino , Humanos , Pessoa de Meia-Idade , Prognóstico , Estudos RetrospectivosRESUMO
Pressurized low polarity water (PLPW) fractionation of triticale straw was optimized to maximize hemicellulose and lignin yield, and to produce a cellulose rich fraction for biofuels production. The optimum PLPW conditions for hemicellulose yield was determined to be 165 °C, with a flow rate of 115 mL/min, and a solvent-to-solid ratio of 60 mL/g. Hemicellulose and lignin yield generally increased with increasing temperature and solvent-to-solid ratio. There was a small decrease in hemicellulose yield with an increase in flow rate. Minimum lignin content of the triticale straw residue after extraction was predicted to occur at a processing condition of 206 °C, 160 mL/min, and 67 mL/g. PLPW was successful in removing 73-78% of the hemicellulose, leaving a cellulose rich fraction (65% glucose concentration). Lignin was equally distributed between the solid residues and the extracts and most of the hemicellulose was extracted in oligomer form. Remaining solid residues after fractionation were highly digestible by cellulase enzymes.