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1.
Brain Res ; 1826: 148730, 2024 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-38128813

RESUMO

Frontal midline θ (Fmθ) activity occurs in medial prefrontal cortices (mPFC), when expected and actual outcomes conflict. Cerebellar forward models could inform the mPFC about this mismatch. To verify this hypothesis we correlated the mPFC activation during a visuomotor tracking task (VM) with performance accuracy, in control and cerebellum-lesioned participants. Additionally, purely visual (V), motor (M) and a motor plus visual tasks (V + M) were performed. An Independent Component, with a mid-frontal topography scalp map and equivalent dipole location in the dorsal anterior cingulate cortex accounted for Fmθ. In control participants Fmθ power increased during VM, when the error level crossed a threshold, but not during V + M, M and V. This increase scaled with tracking error. Fmθ power failed to increase during VM in cerebellar participants, even at highest tracking errors. Thus, in control participants, activation of mPFC is induced when a continuous monitoring effort for online error detection is required. The presence of a threshold error for enhancing Fmθ, suggests the switch from an automatic to an executive tracking control, which recruits the mPFC. Given that the cerebellum stores forward models, the absence of Fmθ increases during tracking errors in cerebellar participants indicates that cerebellum is necessary for supplying the mPFC with prediction error-related information. This occurs when automatic control falters, and a deliberate correction mechanism needs to be triggered. Further studies are needed to verify if this alerting function also occurs in the context of the other cognitive and non-cognitive functions in which the cerebellum is involved.


Assuntos
Córtex Pré-Frontal , Ritmo Teta , Humanos , Ritmo Teta/fisiologia , Córtex Pré-Frontal/fisiologia , Função Executiva/fisiologia , Giro do Cíngulo/fisiologia , Cerebelo
2.
Nat Commun ; 14(1): 386, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36693825

RESUMO

Ultrafast optical-domain spectroscopies allow to monitor in real time the motion of nuclei in molecules. Achieving element-selectivity had to await the advent of time resolved X-ray spectroscopy, which is now commonly carried at X-ray free electron lasers. However, detecting light element that are commonly encountered in organic molecules, remained elusive due to the need to work under vacuum. Here, we present an impulsive stimulated Raman scattering (ISRS) pump/carbon K-edge absorption probe investigation, which allowed observation of the low-frequency vibrational modes involving specific selected carbon atoms in the Ibuprofen RS dimer. Remarkably, by controlling the probe light polarization we can preferentially access the enantiomer of the dimer to which the carbon atoms belong.

3.
Nat Commun ; 13(1): 5052, 2022 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-36030293

RESUMO

UV resonance Raman spectroscopy of size-selected linear sp-carbon chains unveils vibrational overtones and combinations up to the fifth order. Thanks to the tunability of the synchrotron source, we excited each H-terminated polyyne (HCnH with n = 8,10,12) to the maxima of its vibronic absorption spectrum allowing us to precisely determine the electronic and vibrational structure of the ground and excited states for the main observed vibrational mode. Selected transitions are shown to enhance specific overtone orders in the Raman spectrum in a specific way that can be explained by a simple analytical model based on Albrecht's theory of resonance Raman scattering. The determined Huang-Rhys factors indicate a strong and size-dependent electron-phonon coupling increasing with the sp-carbon chain length.

4.
Braz J Med Biol Res ; 55: e11916, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35584451

RESUMO

Here we investigated the effects of physical training on cardiovascular autonomic control and cardiac morphofunctional parameters in spontaneously hypertensive rats (SHRs) subjected to ovarian hormone deprivation. Forty-eight 10-week-old SHRs were divided into two groups: ovariectomized (OVX, n=24) and sham (SHAM, n=24). Half of each group (n=12) was trained by swimming for 12 weeks (OVX-T and SHAM-T). Cardiac morphology and functionality were assessed using echocardiography, and autonomic parameters were assessed using double pharmacological autonomic block, baroreflex sensitivity (BRS), and analyses of heart rate variability (HRV) and blood pressure variability (BPV). Ovariectomy did not influence the cardiac autonomic tonus balance unlike physical training, which favored greater participation of the vagal autonomic tonus. Ovariectomy and aerobic physical training did not modify HRV and BRS, unlike BPV, for which both methods reduced low-frequency oscillations, suggesting a reduction in sympathetic vascular modulation. Untrained ovariectomized animals showed a reduced relative wall thickness (RWT) and increased diastolic and systolic volumes and left ventricular diameters, resulting in increased stroke volume. Trained ovariectomized animals presented reduced posterior wall thickness and RWT as well as increased final diastolic diameter, left ventricular mass, and stroke volume. Ovarian hormone deprivation in SHRs promoted morphofunctional adaptations but did not alter the evaluation of cardiac autonomic parameters. In turn, aerobic physical training contributed to a more favorable cardiac autonomic balance to the vagal autonomic component and promoted morphological adaptations but had little effect on cardiac functionality.


Assuntos
Hipertensão , Condicionamento Físico Animal , Animais , Sistema Nervoso Autônomo/fisiologia , Barorreflexo/fisiologia , Pressão Sanguínea/fisiologia , Feminino , Coração , Frequência Cardíaca/fisiologia , Hormônios/farmacologia , Hipertensão/terapia , Condicionamento Físico Animal/fisiologia , Ratos , Ratos Endogâmicos SHR , Ratos Wistar
5.
Braz. j. med. biol. res ; 55: e11916, 2022. graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1374709

RESUMO

Here we investigated the effects of physical training on cardiovascular autonomic control and cardiac morphofunctional parameters in spontaneously hypertensive rats (SHRs) subjected to ovarian hormone deprivation. Forty-eight 10-week-old SHRs were divided into two groups: ovariectomized (OVX, n=24) and sham (SHAM, n=24). Half of each group (n=12) was trained by swimming for 12 weeks (OVX-T and SHAM-T). Cardiac morphology and functionality were assessed using echocardiography, and autonomic parameters were assessed using double pharmacological autonomic block, baroreflex sensitivity (BRS), and analyses of heart rate variability (HRV) and blood pressure variability (BPV). Ovariectomy did not influence the cardiac autonomic tonus balance unlike physical training, which favored greater participation of the vagal autonomic tonus. Ovariectomy and aerobic physical training did not modify HRV and BRS, unlike BPV, for which both methods reduced low-frequency oscillations, suggesting a reduction in sympathetic vascular modulation. Untrained ovariectomized animals showed a reduced relative wall thickness (RWT) and increased diastolic and systolic volumes and left ventricular diameters, resulting in increased stroke volume. Trained ovariectomized animals presented reduced posterior wall thickness and RWT as well as increased final diastolic diameter, left ventricular mass, and stroke volume. Ovarian hormone deprivation in SHRs promoted morphofunctional adaptations but did not alter the evaluation of cardiac autonomic parameters. In turn, aerobic physical training contributed to a more favorable cardiac autonomic balance to the vagal autonomic component and promoted morphological adaptations but had little effect on cardiac functionality.

6.
Ann R Coll Surg Engl ; 102(7): 504-509, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32799666

RESUMO

INTRODUCTION: The aim of the study was to establish the natural history of elderly patients with non-metastatic colorectal cancer who underwent non-operative management in comparison with those who underwent operative management. MATERIALS AND METHODS: A retrospective analysis of patients aged 80 years and above diagnosed with colorectal cancer between 2007 and 2015 in a tertiary care hospital in the Southwest of England was done. Patients were divided into non-operatively managed and operatively managed groups. Clinical demographics, Charlson Comorbidity Index, location of the tumour and overall survival between the two groups were compared. RESULTS: A total of 407 patients were studied; 132 were treated non-operatively and 275 operatively. The non-operative group included fewer right-sided colon cancers (28.7% vs 54.9%), but significantly more rectal cancers were managed non-operatively (43.9 vs 23.6%, respectively). The two and five year overall survival was 38.9% and 11.3% respectively in the non-operative group, significantly lower than patients in the operative group where the two and five year survival was 78.9% and 59.6% respectively (p = .0001). The median Charlson Comorbidity Index was 7.99 for the non-operative group and 7.49 in the operative group (p = 0.109). Patients treated non-operatively were deemed unfit without objective frailty assessment and only 43/132(32.6%) had formal anaesthetic assessment before being deemed unfit for surgery. CONCLUSION: The survival of octa- and nonagenarians with non-metastatic colorectal cancer managed conservatively is significantly less than counterparts managed operatively. Our present strategy of deciding and denying treatment of the elderly patient with colorectal cancer is arbitrary, highlighting the need for robust geriatric and frailty assessment.


Assuntos
Neoplasias Colorretais/terapia , Tratamento Conservador/métodos , Estadiamento de Neoplasias , Idoso de 80 Anos ou mais , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/epidemiologia , Inglaterra/epidemiologia , Feminino , Seguimentos , Humanos , Masculino , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida/tendências
7.
Phys Chem Chem Phys ; 22(20): 11583-11592, 2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32400802

RESUMO

The human telomeric G-quadruplex structural motif of DNA has come to be known as a new and stimulating target for anticancer drug discovery. Small molecules that interact with G-quadruplex structures in a selective way have gained impressive interest in recent years as they may serve as potential therapeutic agents. Here, we show how circular dichroism, UV resonance Raman and small angle X-ray scattering spectroscopies can be effectively combined to provide insights into structural and molecular aspects of the interaction between human telomeric quadruplexes and ligands. This study focuses on the ability of berberine and palmatine to bind with human telomeric quadruplexes and provides analysis of the conformational landscape visited by the relevant complexes upon thermal unfolding. With increasing temperature, both free and bound G-quadruplexes undergo melting through a multi-state process, populating different intermediate states. Despite the structural similarity of the two ligands, valuable distinctive features characterising their interaction with the G-quadruplex emerged from our multi-technique approach.


Assuntos
Alcaloides de Berberina/metabolismo , Berberina/metabolismo , DNA/metabolismo , Quadruplex G , Berberina/química , Alcaloides de Berberina/química , Dicroísmo Circular , DNA/química , DNA/genética , Humanos , Ligantes , Espalhamento a Baixo Ângulo , Análise Espectral Raman , Difração de Raios X
8.
Tech Coloproctol ; 24(7): 685-694, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32377984

RESUMO

BACKGROUND: The aim of this study was to assess the efficacy of an endoluminal vacuum device (Endo-SPONGE®) in the treatment of rectal anastomotic leaks. METHODS: All studies looking at endoluminal vacuum therapy with Endo-SPONGE® in the treatment of rectal anastomotic leaks were included. A comprehensive search was conducted as per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Primary outcome was defined as the rate of total anastomotic salvage, with secondary outcomes including rate of ileostomy closure, additional transrectal closures and functional outcomes RESULTS: Sixteen studies met the inclusion criteria. There was a significant publication bias (z = 3.53, p = 0.0004). Two hundred sixty-six patients were identified. The median treatment failure rate was 11.8% (range 0-44%), with random effects model of 0.17 (95% CI 0.11-0.22). There was improvement with early therapy start (OR 3.48) and negative correlation with neoadjuvant radiotherapy (OR 0.56). Fifty-one percent of all diverting stomas were closed at the end of treatment period and 12.8% of patients required an additional trans-rectal closure of the abscess cavity. CONCLUSIONS: Endo-SPONGE® seems to be a useful method of rectal anastomotic leak treatment in selected group of patients; however, the quality of available data is poor and it is impossible to draw a final conclusion. There is unexpected high rate of permanent ileostomy. There is a need for further assessment of this therapy with well-designed randomised or cohort studies.


Assuntos
Neoplasias Retais , Estomas Cirúrgicos , Anastomose Cirúrgica/efeitos adversos , Fístula Anastomótica/etiologia , Feminino , Humanos , Ileostomia/efeitos adversos , Neoplasias Retais/cirurgia , Reto/cirurgia , Resultado do Tratamento
9.
Nutr Res Rev ; 33(2): 218-234, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32100670

RESUMO

In the current post-antibiotic era, botanicals represent one of the most employed nutritional strategies to sustain antibiotic-free and no-antibiotic-ever production. Botanicals can be classified either as plant extracts, meaning the direct products derived by extraction from the raw plant materials (essential oils (EO) and oleoresins (OR)), or as nature-identical compounds (NIC), such as the chemically synthesised counterparts of the pure bioactive compounds of EO/OR. In the literature, differences between the use of EO/OR or NIC are often unclear, so it is difficult to attribute certain effects to specific bioactive compounds. The aim of the present review was to provide an overview of the effects exerted by botanicals on the health status and growth performance of poultry and pigs, focusing attention on those studies where only NIC were employed or those where the composition of the EO/OR was defined. In particular, phenolic compounds (apigenin, quercetin, curcumin and resveratrol), organosulfur compounds (allicin), terpenes (eugenol, thymol, carvacrol, capsaicin and artemisinin) and aldehydes (cinnamaldehyde and vanillin) were considered. These molecules have different properties such as antimicrobial (including antibacterial, antifungal, antiviral and antiprotozoal), anti-inflammatory, antioxidant, immunomodulatory, as well as the improvement of intestinal morphology and integrity of the intestinal mucosa. The use of NIC allows us to properly combine pure compounds, according to the target to achieve. Thus, they represent a promising non-antibiotic tool to allow better intestinal health and a general health status, thereby leading to improved growth performance.


Assuntos
Ração Animal , Criação de Animais Domésticos/métodos , Anti-Infecciosos/farmacologia , Nível de Saúde , Extratos Vegetais/farmacologia , Aves Domésticas , Suínos , Acroleína/análogos & derivados , Acroleína/farmacologia , Animais , Antibacterianos , Benzaldeídos/farmacologia , Suplementos Nutricionais , Dissulfetos/farmacologia , Intestinos/efeitos dos fármacos , Magnoliopsida/química , Carne , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Fenóis/farmacologia , Extratos Vegetais/biossíntese , Extratos Vegetais/química , Aves Domésticas/crescimento & desenvolvimento , Aves Domésticas/microbiologia , Ácidos Sulfínicos/farmacologia , Suínos/crescimento & desenvolvimento , Suínos/microbiologia , Terpenos/farmacologia
11.
Microb Pathog ; 132: 45-50, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31015015

RESUMO

Bovine mastitis affects dairy cattle worldwide and Staphylococcus aureus is one of the most common microorganisms involved in subclinical and chronic disease. Superantigens, such as enterotoxins contribute to S. aureus persistence and pathogenicity in this disease. Subclinical and chronic mastitis cases were diagnosed and S. aureus isolates from sub-clinical cases were investigated for carriage of virulence and antibiotic resistance genes that may contribute to long-term carriage and infection. Over a 12-month period, 116 S. aureus strains were recovered from 68 cows with subclinical mastitis. Classical enterotoxin genes (sea-see) were detected in 24.1% of isolates, and pvl and tsst-1 were identified in 3.4% and 46.6% the isolates, respectively. 18.1% that were persistent isolates were identified and characterized by pulsed field gel electrophoresis (PFGE), MLST, spa typing. Four isolates were methicillin-resistant S. aureus (MRSA) and belonged to SCCmec type I. Molecular typing showed that the agrI group was the most frequent, and a rare isolate was positive for both agrI and agrIII groups. Molecular characterization revealed the persistence of the spa type t10856 (ST133, clonal complex CC133, agr I), in a single animal for nine months and the persistence t605 (ST126, CC126) colonizing four animals for four months. These strains have been described recently in other herds in the same region, indicating their transmissibility and clonal expansion. We conclude that animals with subclinical mastitis are an important and somewhat overlooked reservoir for transmission within and between herds, and may carry virulence and antibiotic resistance genes contributing to persistent colonization, hinder the control of mastitis and may cause risks to the public health.


Assuntos
Genótipo , Mastite Bovina/microbiologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidade , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Bovinos , DNA Bacteriano , Eletroforese em Gel de Campo Pulsado , Enterotoxinas/genética , Exotoxinas/genética , Feminino , Leucocidinas/genética , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Leite/microbiologia , Tipagem Molecular/métodos , Tipagem de Sequências Multilocus , Staphylococcus aureus/isolamento & purificação , Superantígenos/genética , Transativadores/genética , Virulência/genética , Fatores de Virulência/genética
12.
Microb Pathog ; 124: 130-135, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30138758

RESUMO

Bovine mastitis has been a concern for dairy herd for decades. The adaptation capacity of one of the main species responsible for this disease, Staphylococcus aureus (S. aureus), plays a pivotal role in this issue. The aim of this study was to establish a molecular and phenotypic profile of 285 S. aureus strains isolated from milk of subclinical mastitis cows from 18 different farms in São Paulo State using spa typing, multilocus sequence typing (MLST), pulsed field gel electrophoresis (PFGE), agr cluster (I, II, III and IV) typing, PCR for genes including enterotoxins (sea, seb, sec, sed, see, seg, seh, sei), toxic shock syndrome toxin (tsst-1), and Panton-Valentine leucocidin (pvl), as well as in vitro resistance assays for 12 antibiotics. The results showed a wide variety of strains with a high toxigenic potential; concomitantly, sec, seg and seh were prevalent. In addition, we observed a predominance of the spa types t605 (ST 126, CC126) and t127 (ST1, CC1) and the unusual presence of t321 causing bovine mastitis, which has been previously reported only in swine. The most frequent ST were ST126 (70.5%) and ST1 (10.5%). Regarding PFGE, we observed four major groups and six profile patterns. The highest resistance was observed for streptomycin (9.5%), followed by tetracycline (3.5%), clindamycin (9.3%), and erythromycin (2.8%). The tsst-1 gene was detected in 36.8% of isolates and pvl was not observed. One hundred and thirty-six (47.7%) isolates possessed agr type II, followed by types III (20%) and I (8.1%), with type IV not being detected. We observed that the same spa type could result in different PFGE profiles, so the exclusive use of spa type sequences can lead to incorrect interpretations regarding the spread of clones in an epidemiological context.


Assuntos
Infecções Assintomáticas , Mastite Bovina/epidemiologia , Mastite Bovina/microbiologia , Leite/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/classificação , Staphylococcus aureus/genética , Animais , Antibacterianos/farmacologia , Brasil/epidemiologia , Bovinos , Farmacorresistência Bacteriana , Eletroforese em Gel de Campo Pulsado , Técnicas de Genotipagem , Epidemiologia Molecular , Tipagem de Sequências Multilocus , Reação em Cadeia da Polimerase , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação , Fatores de Virulência/genética
13.
J Dairy Sci ; 101(11): 10220-10229, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30146291

RESUMO

The objectives of this study were to estimate the accuracy of Somaticell (Idexx Laboratories Inc., Westbrook, ME), California Mastitis Test (CMT), and microbiological examination of composite milk (MEC) to diagnose Streptococcus agalactiae intramammary infections (IMI), and to assess the agreement between Somaticell and CMT to detect these infections. A secondary objective was to estimate quarter- and cow-level prevalence of S. agalactiae IMI in the herds included in the study. Seven farms were included in the study. The CMT was performed and aseptic milk samples were collected from all quarters of all lactating cows. Composite milk samples were produced in the laboratory by mixing milk from all quarters of each sampled cow. The Somaticell test was performed on a subset of S. agalactiae-positive (n = 167) and S. agalactiae-negative (n = 152) quarter milk samples. Microbiological examination of quarter milk samples (MEQ) was considered the reference test for diagnosing S. agalactiae IMI. The accuracy of all tests at various thresholds was estimated using Bayesian latent class models. Apparent prevalence of S. agalactiae IMI was 15.8% (n = 184/1,164) at the quarter level (based on MEQ) and 28.5% (n = 83/291) at the cow level (based on MEC). True prevalence, as determined by Bayesian models, was 13.0% [95% credible interval (CR): 6.4-24.4%] at the quarter level, and 25.6% (95% CR: 15.3-39.5%) at the cow level. At the cow level (n = 285), sensitivity and specificity of MEC were 95.6 and 99.5%, respectively. The accuracy of Somaticell (n = 319 quarters) to identify S. agalactiae-infected quarters was 75.4, 86.4, 88.9, 89.4, and 91.0% at thresholds of 98,000, 147,000, 205,000, 244,000, and 282,000 cells/mL, respectively. The accuracy of CMT was 87.6, 90.7, 90.8, and 87.4% at thresholds of trace, 1, 2, and 3, respectively. The areas under the receiver operating characteristic curve for Somaticell and CMT were 94.5% (95% confidence interval: 91.8-97.2%) and 92.0% (88.6-95.4%), respectively. At the tested thresholds, the sensitivity of Somaticell ranged from 94.9 to 99.5% to detect S. agalactiae IMI, and specificity ranged from 48.1 to 87.1%. The sensitivity of Somaticell at the lowest threshold (69,000 cells/mL; sensitivity = 99.9%; 95% CR: 98.2-100%) was higher than that of CMT at any tested threshold. Results of this study could be used at the farm level to reduce the use of antimicrobials and reach specific goals in S. agalactiae eradication programs.


Assuntos
Mastite Bovina/diagnóstico , Leite/microbiologia , Infecções Estreptocócicas/veterinária , Streptococcus agalactiae/isolamento & purificação , Animais , Teorema de Bayes , California/epidemiologia , Bovinos , Fazendas , Feminino , Lactação , Mastite Bovina/epidemiologia , Mastite Bovina/microbiologia , Leite/normas , Prevalência , Sensibilidade e Especificidade , Infecções Estreptocócicas/diagnóstico , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/microbiologia
14.
Sci Rep ; 8(1): 6105, 2018 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-29666447

RESUMO

Invertebrates represent the most plentiful component of marine biodiversity. To date, only few species have been documented for marine litter intake. Here, we report for the first time the presence of macroplastic debris in a jellyfish species. Such novel target to plastic pollution highlights an under studied vector of marine litter along marine trophic web, raising further concern over the impact on marine wildlife.


Assuntos
Plásticos , Comportamento Predatório , Cifozoários/fisiologia , Poluentes da Água , Animais , Ingestão de Alimentos , Monitoramento Ambiental , Cadeia Alimentar , Plásticos/efeitos adversos , Poluentes da Água/efeitos adversos
15.
Phys Chem Chem Phys ; 19(33): 22555-22563, 2017 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-28809977

RESUMO

UV Raman and Brillouin light scattering (BLS) experiments have been used in this study to explore the complex phase change behavior occurring in pH-responsive polysaccharide hydrogels as a function of temperature. Due to the different physical quantities measured by the two techniques, the joint analysis of Raman and BLS spectra has provided an unprecedented large-scale characterization of the molecular rearrangements and of the different kinds of hydrophilic and hydrophobic interactions that cooperate to determine the phase transformation observed in these hydrogels during the heating of the gel. As the main result, the analysis of the Raman and BLS spectra showed the existence of a correlation between the local (molecular) and collective properties of the gels during the phase transformation undergone by the system, which is markedly triggered by pH. The joint set of experimental results suggests a model according to which the mechanism of pH dependence in the hydrogels under investigation is dominated by the interactions involving the hydrophobic parts of the polymer skeleton, whereas the solvation process observed under heating of the gels is driven by the progressive distancing of the polymer domains among them, as monitored by the Brillouin sound velocity.

16.
Gait Posture ; 57: 130-135, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28623760

RESUMO

This is an observational cross-sectional study evaluating gait dynamics in patients with Parkinson's Disease (PD) and severe postural deformities, PD without axial deviations and healthy subjects. Ten PS individuals with Pisa syndrome (PS) and nine subjects with Camptocormia (CC) performed 3-D Gait Analysis and were evaluated with walking and balance scales. Correlations with clinical and functional scales were investigated. Spatio-temporal and kinematic data were compared to ten PD subjects without postural deformities (PP) and ten healthy matched individuals (CG). Data obtained showed decreased walking velocity, stride and step length in PP, PS and CC groups compared to controls. The correlation analysis showed that stride and step length were associated with reduced functional abilities and disease severity in PS and CC groups. Kinematic data revealed marked reduction in range of movements (ROMs) at all lower-extremity joints in PS group. While, in CC group the main differences were pronounced in hip and knee joints. PS and CC groups presented a more pronounced reduction in hip articular excursion compared to PP subjects, revealing an increased hip flexion pattern during gait cycle. Moreover, the increased hip and knee flexion pattern adversely affected functional performance during walking tests. Results obtained provide evidence that step length, along with stride length, can be proposed as simple and clear indicators of disease severity and reduced functional abilities. The reduction of ROMs at hip joint represented an important mechanism contributing to decreased walking velocity, balance impairment and reduced gait performance in PD patients with postural deformities.


Assuntos
Avaliação da Deficiência , Marcha/fisiologia , Articulação do Quadril/fisiopatologia , Atrofia Muscular Espinal/fisiopatologia , Equilíbrio Postural/fisiologia , Curvaturas da Coluna Vertebral/fisiopatologia , Caminhada/fisiologia , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Estudos Transversais , Pessoas com Deficiência/reabilitação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Atrofia Muscular Espinal/reabilitação , Doença de Parkinson/fisiopatologia , Doença de Parkinson/reabilitação , Curvaturas da Coluna Vertebral/reabilitação , Síndrome
17.
J Environ Manage ; 197: 41-49, 2017 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-28319832

RESUMO

The study addresses the life cycle cost assessment (LCCA) of steel bridges, focusing on the maintenance activities and the maintenance scenario. Firstly, the unit costs of maintenance activities and their durability (i.e. the time between two activities) are evaluated. Pragmatic data are provided for the environment category C4 and for three activities: Patch Up, Overcoating and Remove & Replace. A comparative LCCA for a typical hypothetic steel girder bridge is carried out, either painted or hot-dip galvanized (HDG), in the environmental class C4. The LCC versus the cumulated life is provided for both options. The initial cost of the steel unpainted option is only 50.3% of the HDG option. It is shown that after 'Overcoating' occurring at 18.5 years, the total Net Present Value (NPV) of the painted option surpasses that of the HDG option. A sensitivity analysis of the NPV to the cost and service life parameters, the escalation and discount rates is then performed. The discount and escalation rates, considerably influences the total LCC, following a non-linear trend. The total LCC decreases with the discount rate increasing and, conversely, increases with the escalation rate increasing. Secondly, the influence of the maintenance scenario on the total LCC is assessed based on a probabilistic approach. A permutation of the three independent maintenance activities assumed to occur six times over the life of the bridge is considered and a probability of occurrence is associated to each unique scenario. The most probable scenarios are then classified according to their NPV or achieved service life. This approach leads to the definition of a cost-effective maintenance scenario i.e. the scenario, within all the considered permutations, that has the minimum LCC in a range of lifespan. Besides, the probabilistic analysis also shows that, whatever the scenario, the return on investment period ranges between 18.5 years and 24.2 years. After that period, the HDG option becomes economic.


Assuntos
Pintura , Aço , Análise Custo-Benefício
18.
Phys Chem Chem Phys ; 19(8): 6022-6029, 2017 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-28184405

RESUMO

The focus of this work is on addressing how the adsorption properties of cyclodextrin (CD) based polymeric hydrogels (cyclodextrin nanosponges, CDNS) can be regulated by a precise control of a crucial parameter such as the characteristic pore size of the polymer network. With this aim, Small Angle Neutron Scattering (SANS) experiments are performed on different CDNS polymer formulations, differing by (i) the chemical structure of the cross-linking agent used for the polymerization of CD, which affects the flexibility of the strands between two crosslinking junctions, (ii) the relative molar ratio of cross-linker to monomer, affecting the cross-linking density, and (iii) the dimension of the CD macrocycle, regulating the steric hindrance and number of available reactive sites on the monomer. The analysis of the experimental data in terms of a two-correlation-length model allows one to extract a correlation length ζ that is interpreted as an experimental assessment of the average mesh-size of the cross-linked polymer, confirming the effective nano-size of the cavities formed in the network of CDNS. The hydration-dependence of ζ is modelled by an empirical functional form, that provides as key parameters the swelling rate of the polymeric network and the upper limit for the mesh size of the material. These parameters are useful for the characterization of the dynamic response of the hydrogel to swelling and the maximum mesh size compatible with the chemical structure of the polymer.

19.
Cryo Letters ; 37(4): 243-252, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27925007

RESUMO

BACKGROUND: The effect of freezing-thawing equine adipose tissue-derived mesenchymal stem cells (eATMSCs) have been poorly investigated. OBJECTIVE: This study is to test the influence of cryopreservation solution and temperature when adding the cryoprotectant for freezing eATMSCs, and to investigate the effects of cryopreservation on their stemness features. MATERIALS AND METHODS: Four freezing protocols were evaluated. Viability and proliferation ability of cryopreserved cells were investigated by MTT assay. Fresh and frozen thawed eATMSCs were compared for morphology, phenotypic characteristics (flow cytometry), and differentiation potential. RESULTS: A higher value of viable cells for samples frozen in FBS and a positive effect of CPA equilibration at low temperature in samples frozen in medium were observed. Morphology was similar for fresh and cryopreserved cells, such as CD expression and differentiation potential. CONCLUSION: eATMSCs can be safely stored for clinical use. FBS is superior to medium for freezing, but CPA equilibration at low temperature is beneficial when freezing in serum- free medium.


Assuntos
Tecido Adiposo/citologia , Criopreservação/métodos , Crioprotetores/farmacologia , Meios de Cultura Livres de Soro/farmacologia , Células-Tronco Mesenquimais/fisiologia , Animais , Diferenciação Celular/efeitos dos fármacos , Citometria de Fluxo , Congelamento , Cavalos , Células-Tronco Mesenquimais/citologia
20.
Soft Matter ; 12(43): 8861-8868, 2016 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-27734051

RESUMO

The focus of the present work is to shed light on possible modifications of the molecular properties of polysaccharide hydrogels induced by the establishment of specific non-covalent interactions during the loading of a guest compound inside the gel phase. With this aim, a case study of the encapsulation of caffeine (Caf) inside cyclodextrin-based hydrogels, namely, cyclodextrin nanosponges (NS), is systematically investigated here by using UV Raman scattering experiments. The UV Raman spectra of the hydrogels, analysed as a function of temperature, concentration of the guest molecule loaded in the gel phase and pH, prove particularly informative both on the structural rearrangements of the hydrophobic/hydrophilic groups of the polymeric network and on the breaking/formation of specific guest-matrix interactions. Analysis of the temperature dependence of dynamical parameters, i.e., the dephasing time associated with specific vibrational modes of the polymer backbone, enables the proposal of a molecular picture in which the loading of Caf in NS hydrogels tends to favour access of the water solvent to the more hydrophobic portions of the polymer matrix, which is in turn reflected in a marked increase in the solvation of the whole system. The achievements of this work appear of interest with respect to the design of new possible strategies for controlling the diffusion/release of bioactive molecules inside hydrogel networks, besides corroborating the potential of UV Raman scattering experiments to give new molecular insights into complex phenomena affecting hydrogel phases.

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