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1.
Clin Lab ; 68(3)2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35254021

RESUMO

BACKGROUND: The SARS-CoV-2 outbreak started in March 2020 with more than 120,552,261 cases at present and having caused over 2,667,248 deaths worldwide at the time this paper was written. The clinical signs of SARS-CoV-2 infection are especially evident in the respiratory and cardiovascular systems. Patients can be asymptomatic or present mild respiratory symptoms to severe acute lung injury leading to multiorgan failure and death. The study aims to assess the levels of serum 25-hydroxyvitamin D (25-(OH)-D) in 20 hospitalized patients infected with SARS-CoV-2 and 20 deceased people and to analyze the influence of vitamin D status on the severity of their disease. METHODS: The present study was conducted on 40 patients who tested positive for SARS-CoV-2 infection. They were divided into two groups: 20 patients admitted to the "Victor Babes" Hospital of Infectious Diseases and 20 postmortem cases autopsied at the Institute of Legal Medicine Timisoara, Romania. During the autopsy, blood and bronchial fluid samples were collected for the laboratory. Automate Viral RNA extraction was performed on the Maxwell 48 RSC Extraction System (Promega, USA) using the Maxwell RSC Viral Total Nucleic Acid Purification kit (Promega, USA). After RNA extraction, the samples were amplified on a 7500 real-time PCR (Applied Biosystems, USA) using the genesig® Real-Time PCR Assay 2G (Primer Design, UK). RESULTS: The living and deceased patients selected for the research presented decreased vitamin D levels, which are associated with increased levels of D-dimers, C reactive protein (CRP), and interleukin-6 (IL-6). These patients had a severe form of the SARS-CoV-2 disease, which led to death. CONCLUSIONS: We conclude that deficiency of vitamin D in patients infected with SARS-CoV-2 presents a major risk factor related to the evolution and severity of the disease.


Assuntos
COVID-19 , Deficiência de Vitamina D , Humanos , Fatores de Risco , SARS-CoV-2 , Vitamina D , Deficiência de Vitamina D/diagnóstico , Deficiência de Vitamina D/epidemiologia , Vitaminas
2.
J Biol Regul Homeost Agents ; 35(1 Suppl. 2): 21-25, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33982534

RESUMO

Pseudomonas aeruginosa is an opportunistic human pathogen that frequently induces antibiotic resistance, as it mainly tends to form biofilms. Iron chelation may be an intriguing strategy to contrast bacterial growth. Lactoferrin is a natural compound able to chelate iron. A new multi-component medical device also contains lactoferrin. This study analyzed this compound investigating the in vitro capacity to inhibit Pseudomonas aeruginosa growth. In conclusion, this study demonstrated that a multicomponent medical device (Saflovir), also containing lactoferrin, could inhibit the in vitro growth of P. aeruginosa. This activity could be positively used in the prevention of respiratory nasal infections.


Assuntos
Pseudomonas aeruginosa , Infecções Respiratórias , Antibacterianos/farmacologia , Biofilmes , Humanos , Ferro/metabolismo , Lactoferrina/farmacologia , Pseudomonas aeruginosa/metabolismo
3.
J Neuroeng Rehabil ; 18(1): 102, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-34167546

RESUMO

BACKGROUND: Rehabilitative treatment plans after stroke are based on clinical examinations of functional capacity and patient-reported outcomes. Objective information about daily life performance is usually not available, but it may improve therapy personalization. OBJECTIVE: To show that sensor-derived information about daily life performance is clinically valuable for counseling and the planning of rehabilitation programs for individual stroke patients who live at home. Performance information is clinically valuable if it can be used as a decision aid for the therapeutic management or counseling of individual patients. METHODS: This was an observational, cross-sectional case series including 15 ambulatory stroke patients. Motor performance in daily life was assessed with body-worn inertial sensors attached to the wrists, shanks and trunk that estimated basic physical activity and various measures of walking and arm activity in daily life. Stroke severity, motor function and activity, and degree of independence were quantified clinically by standard assessments and patient-reported outcomes. Motor performance was recorded for an average of 5.03 ± 1.1 h on the same day as the clinical assessment. The clinical value of performance information is explored in a narrative style by considering individual patient performance and capacity information. RESULTS: The patients were aged 59.9 ± 9.8 years (mean ± SD), were 6.5 ± 7.2 years post stroke, and had a National Institutes of Health Stroke Score of 4.0 ± 2.6. Capacity and performance measures showed high variability. There were substantial discrepancies between performance and capacity measures in some patients. CONCLUSIONS: This case series shows that information about motor performance in daily life can be valuable for tailoring rehabilitative therapy plans and counseling according to the needs of individual stroke patients. Although the short recording time (average of 5.03 h) limited the scope of the conclusions, this study highlights the usefulness of objective measures of daily life performance for the planning of rehabilitative therapies. Further research is required to investigate whether information about performance in daily life leads to improved rehabilitative therapy results.


Assuntos
Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Estudos Transversais , Humanos , Estados Unidos , Caminhada
4.
Phys Rev Lett ; 125(10): 102502, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32955302

RESUMO

The low-spin structure of the semimagic ^{64}Ni nucleus has been considerably expanded: combining four experiments, several 0^{+} and 2^{+} excited states were identified below 4.5 MeV, and their properties established. The Monte Carlo shell model accounts for the results and unveils an unexpectedly complex landscape of coexisting shapes: a prolate 0^{+} excitation is located at a surprisingly high energy (3463 keV), with a collective 2^{+} state 286 keV above it, the first such observation in Ni isotopes. The evolution in excitation energy of the prolate minimum across the neutron N=40 subshell gap highlights the impact of the monopole interaction and its variation in strength with N.

5.
Int Endod J ; 53(8): 1120-1130, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32383495

RESUMO

AIM: To assess a novel, noninvasive intervention capable of mobilizing charged antibacterial nanoparticles to the apical portions of the root canal system, utilizing the principles of electrokinetics. METHODS: Experiments were conducted in three stages. Stage-1: A computer model was generated to predict and visualize the electric field and current density distribution generated by the proposed intervention. Stage-2: Transport of chitosan nanoparticles (CSnp) was evaluated qualitatively using a transparent microfluidic model with fluorescent-labelled CSnp. Stage-3: An ex vivo model was utilized to study the antimicrobial efficacy of the proposed treatment against 3-week-old monospecies E. faecalis biofilms. Scanning electron microscopy (SEM) was also utilized in this stage to confirm the deposition of CSnp. RESULTS: The results of the computer simulations predicted an electric field and current density that reach their maxima at the apical constriction of the root canal. Correspondingly, the microfluidic experiments demonstrated rapid, controlled CSnp transport throughout the simulated root canal anatomy with subsequent distribution and deposition in the apical constriction as well as periapical regions. Infected root canals when subjected to the novel treatment method resulted in a mean bacterial reduction of 2.1 log CFU. SEM analysis revealed electrophoretic deposition of chitosan nanoparticles onto the root canal dentine walls in the apical region. CONCLUSION: The findings from this study demonstrate that the combination of cationic antibacterial nanoparticles with a low-intensity electric field results in particle transportation (electrophoresis) and deposition within the root canal. This results in a synergistic antibiofilm efficacy and has the potential to enhance root canal disinfection.


Assuntos
Desinfecção , Nanopartículas , Antibacterianos , Biofilmes , Cavidade Pulpar , Enterococcus faecalis , Irrigantes do Canal Radicular , Hipoclorito de Sódio
6.
Philos Trans A Math Phys Eng Sci ; 376(2111)2018 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-29229789

RESUMO

We review recent progress on the long-time regularity of solutions of the Cauchy problem for the water waves equations, in two and three dimensions. We begin by introducing the free boundary Euler equations and discussing the local existence of solutions using the paradifferential approach. We then describe in a unified framework, using the Eulerian formulation, global existence results for three- and two-dimensional gravity waves, and our joint result (with Deng and Pausader) on global regularity for the gravity-capillary model in three dimensions. We conclude this review with a short discussion about the formation of singularities and give a few additional references to other interesting topics in the theory.This article is part of the theme issue 'Nonlinear water waves'.

7.
Phys Rev Lett ; 118(16): 162502, 2017 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-28474931

RESUMO

A search for shape isomers in the ^{66}Ni nucleus was performed, following old suggestions of various mean-field models and recent ones, based on state-of-the-art Monte Carlo shell model (MCSM), all considering ^{66}Ni as the lightest nuclear system with shape isomerism. By employing the two-neutron transfer reaction induced by an ^{18}O beam on a ^{64}Ni target, at the sub-Coulomb barrier energy of 39 MeV, all three lowest-excited 0^{+} states in ^{66}Ni were populated and their γ decay was observed by γ-coincidence technique. The 0^{+} states lifetimes were assessed with the plunger method, yielding for the 0_{2}^{+}, 0_{3}^{+}, and 0_{4}^{+} decay to the 2_{1}^{+} state the B(E2) values of 4.3, 0.1, and 0.2 Weisskopf units (W.u.), respectively. MCSM calculations correctly predict the existence of all three excited 0^{+} states, pointing to the oblate, spherical, and prolate nature of the consecutive excitations. In addition, they account for the hindrance of the E2 decay from the prolate 0_{4}^{+} to the spherical 2_{1}^{+} state, although overestimating its value. This result makes ^{66}Ni a unique nuclear system, apart from ^{236,238}U, in which a retarded γ transition from a 0^{+} deformed state to a spherical configuration is observed, resembling a shape-isomerlike behavior.

9.
J Chem Phys ; 141(8): 084505, 2014 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-25173019

RESUMO

We consider the influence of the spatial dependence of the ions distribution on the effective dielectric constant of an electrolytic solution. We show that in the linear version of the Poisson-Nernst-Planck model, the effective dielectric constant of the solution has to be considered independent of any ionic distribution induced by the external field. This result follows from the fact that, in the linear approximation of the Poisson-Nernst-Planck model, the redistribution of the ions in the solvent due to the external field gives rise to a variation of the dielectric constant that is of the first order in the effective potential, and therefore it has to be neglected in the Poisson's equation that relates the actual electric potential across the electrolytic cell to the bulk density of ions. The analysis is performed in the case where the electrodes are perfectly blocking and the adsorption at the electrodes is negligible, and in the absence of any ion dissociation-recombination effect.

10.
Caries Res ; 48(1): 19-23, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24216624

RESUMO

The effect of Stevia extracts on in vitro Streptococcus mutans biofilm formation and in vivo plaque pH was evaluated in this paper. Three 10% solutions containing stevioside, rebaudioside A or sucrose were prepared. MTT assay was used to evaluate microbiological counts in vitro. Twenty volunteers rinsed for 1 min with each solutions, and plaque pH was measured at 7 time points after each rinse. Higher in vitro S. mutans biofilm formation was observed in sucrose solution (p < 0.01). After 5, 10, 15 and 30 min, the sucrose in vivo rinse produced a statistically significantly lower pH value compared to the Stevia extracts (F = 99.45, p < 0.01).Stevia extracts can be considered nonacidogenic.


Assuntos
Biofilmes/efeitos dos fármacos , Cárie Dentária/microbiologia , Placa Dentária/fisiopatologia , Extratos Vegetais/farmacologia , Stevia , Streptococcus mutans/efeitos dos fármacos , Adulto , Carga Bacteriana/efeitos dos fármacos , Técnicas Bacteriológicas , Corantes , Diterpenos do Tipo Caurano/farmacologia , Feminino , Seguimentos , Glucosídeos/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Masculino , Antissépticos Bucais/farmacologia , Projetos Piloto , Espectrofotometria/métodos , Streptococcus mutans/crescimento & desenvolvimento , Sacarose/farmacologia , Edulcorantes/farmacologia , Sais de Tetrazólio , Tiazóis , Adulto Jovem
11.
Vet Anim Sci ; 23: 100333, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38274773

RESUMO

The dairy cow experiences the most significant impact from negative energy balance during this period, which adversely affects reproductive health. Consequently, most pathologies affect dairy cows during this time frame. Thus, with the primary objective of reducing the incidence of these pathologies on dairy farms, we questioned whether supplemental zeolite administration in cattle feed would affect metabolism and reproductive health. Therefore, we proposed introducing an antepartum and postpartum supplementation of 400 g of zeolite in the basal diet. The control group received only the basal diet without zeolite supplementation. Monitoring the results stemmed from the consideration that reproductive health can only be present based on an unaltered energy metabolism. Hence, we deemed it necessary to analyze several metabolic markers in light of the expected outcomes concerning reproductive health. Cows treated with zeolite exhibited a calving to first service interval 12.78 days earlier than those in the control group. Moreover, the average number of services per conception used for future gestation was 0.44 lower in the zeolite-treated group compared to the control group (p<0.05). Additionally, the treatment group showed a lower presence of pathogens in the uterus and displayed a more favorable average uterine score. Observations following the completion of the research point towards an improvement in the health of transition dairy cows, opening a new path for dairy farms in terms of preventing postpartum pathologies. Indeed, the benefits from this study primarily impact the animals rather than directly influencing milk production. Therefore, further research is necessary in this regard.

12.
Artigo em Inglês | MEDLINE | ID: mdl-38083344

RESUMO

Risk management (RM) is a key component of the development of modern medical devices (MD) to achieve acceptable functional safety and pass the regulatory process. The emerging availability of various techniques, languages, and tools that use model-based system engineering (MBSE) promises to facilitate the development and analysis of complex MD. In this paper, we show how to integrate RM principles and activities recommended in ISO 14971 medical standard into an MBSE-driven MD development process. We propose a method and framework capable of modeling essential RM concepts and performing RM and safety analysis in the early stages of the MD development life cycle. The framework extends OMG RAAML (Object Management Group Risk Analysis and Assessment Modeling Language) to the medical domain according to ISO 14971. We illustrate our approach using a case study of the e-Glass system developed for real-time EEG-based subject monitoring with the intended use of stress monitoring.Clinical Relevance-This facilitates the MD certification process by semi-automation of RM based on ISO 14971 and obtaining safe MD by design.


Assuntos
Eletroencefalografia , Gestão de Riscos , Medição de Risco
13.
J Dent ; 116: 103893, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34798151

RESUMO

OBJECTIVES: To evaluate the effects of microorganisms' contamination inside the dispensing syringes of different types of resin-based composites (RBCs). METHODS: This study encompassed two sections. First, an anonymous electronic survey was submitted via Google forms to Italian dentists to acquire information about composite handling during clinical procedures. Then, a bench test was performed on nanohybrid RBCs differing in matrix chemistry and fillers [FiltekTM Supreme XTE (3MTM); Venus Pearl (Kulzer GmbH); Admira Fusion x-tra (Voco)] to evaluate the microbial viability on their surfaces with/out photocuring. Uncured RBCs were exposed to standardized inocula of Streptococcus Mutans, Candida Albicans, Lactobacillus Rhamnosus, or mixt plaque in an in vitro model reproducing clinical restorative procedures. Half of the RBC specimens were cured after exposure. Microbial viability was assessed using an MTT-based test. Statistical analysis included three-way ANOVA and Tukey's tests (p<0.05). RESULTS: Among 300 dentists completing the survey, the majority declared to use the spatula to carry the RBCs from the syringe to the dental cavity (50% same spatula; 35% two spatulas). However, 80% of respondents had personal feelings that using one spatula could be a source of cross-contamination. In vitro results using one spatula showed microbial contamination of all RBCs after one hour of storage. The contamination levels depended on the used strain and RBC type (p<0.0001), but photocuring did not reduce contamination (p = 0.2992). CONCLUSIONS: Microbial species' viability on uncured RBCs and after photocuring shows the existence of a considerable risk of cross-infection. Clinical procedures in Restorative Dentistry need to acknowledge and to reduce such risk during RBCs handling. CLINICAL SIGNIFICANCE: Dentists must be aware of the possibility of cross-infection during restorative procedures, especially when the same spatula is repeatedly used for placing RBC in the cavity.


Assuntos
Resinas Compostas , Materiais Dentários , Teste de Materiais , Streptococcus mutans
14.
Annu Int Conf IEEE Eng Med Biol Soc ; 2022: 3645-3648, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-36085794

RESUMO

Accurate assessment of the type, duration, and intensity of physical activity (PA) in daily life is considered very important because of the close relationship between PA level, health, and well-being. Therefore, the assessment of PA using lightweight wearable sensors has gained interest in recent years. In particular, the use of activity monitors could help to measure the health-related effects of specific PA interventions. Our study, named as Run4Vit, focuses on evaluating the acute and longterm effects of an eight-week running intervention on PA behaviour and vitality. To achieve this goal, we developed an algorithm to detect running and estimate instantaneous cadence using a single trunk-fixed accelerometer. Cadence was computed using time and frequency domain approaches. Validation was performed over a wide range of locomotion speeds using an open-source gait database. Across all subjects, the cadence estimation algorithms achieved a mean bias and precision of - 0.01 ± 0.69 steps/min for the temporal method and 0.02 ± 1.33 steps/min for the frequency method. The running detection algorithm demonstrated very good performance, with an accuracy of 98% and a precision superior to 99%. These algorithms could be used to extract metrics related to the multiple dimensions of PA, and provide reliable outcome measures for the Run4Vit longitudinal running intervention program. Clinical Relevance- This work aims at validating a multi-dimensional physical activity (PA) classification algorithm for assessing the acute and long-term effects of eight weeks running intervention on PA behaviours and vitality.


Assuntos
Marcha , Caminhada , Acelerometria/métodos , Exercício Físico , Monitores de Aptidão Física , Humanos
15.
Pol J Vet Sci ; 25(3): 397-402, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36156608

RESUMO

Nowadays, a high incidence of cutaneous tumors is observed in domestic carnivorous in pet clinic, the sebaceous glands being the starting point for the development of these tumors. The hormonal imbalances are considered to be the most common etiology for these tumors, so the current research is based on the effects of an androgenic like hormonal drug on the functionality of the sebaceous glands in dogs. For this purpose, 32 dogs were distributed in 4 groups: control group 1 (8 dogs - females), control group 2 (8 dogs - males), experimental group 1 (8 dogs - females) and experimental group 2 (8 dogs - males). The investigation targeted the pH of skin and the rate of sebum's secretion. The animals from the experimental groups were treated with Anabolin forte for 2 days at a dose of 1 mg/kg body weight/day, intramuscular. The obtained results revealed that administration of Anabolin forte in males induced a significantly distinct intensification (with 10.66%) of sebum's secretion and a significant decrease of pH of the skin (with 17.1%) compared to the animals from the control group. The administration of Anabolin forte in females induced a significantly distinct intensification (with 17.47%) of sebum's secretion and a significant decrease of the pH of the skin (with 14.32%) compared to the animals from the control group.


Assuntos
Doenças do Cão , Neoplasias Cutâneas , Androgênios/farmacologia , Animais , Doenças do Cão/tratamento farmacológico , Doenças do Cão/patologia , Cães , Feminino , Estado Funcional , Masculino , Glândulas Sebáceas/patologia , Pele , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/veterinária
16.
Sci Rep ; 12(1): 19132, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36352252

RESUMO

We have investigated the pinning potential of high-quality single crystals of superconducting material CaKFe4As4 having high critical current density and very high upper critical field using both magnetization relaxation measurements and frequency-dependent AC susceptibility. Preliminary studies of the superconducting transition and of the isothermal magnetization loops confirmed the high quality of the samples, while temperature dependence of the AC susceptibility in high magnetic fields show absolutely no dependence on the cooling conditions, hence, no magnetic history. From magnetization relaxation measurements were extracted the values of the normalized pinning potential U*, which reveals a clear crossover between elastic creep and plastic creep. The extremely high values of U*, up to 1200 K around the temperature of 20 K lead to a nearly zero value of the probability of thermally-activated flux jumps at temperatures of interest for high-field applications. The values of the creep exponents in the two creep regimes resulted from the analysis of the magnetization relaxation data are in complete agreement with theoretical models. Pinning potentials were also estimated, near the critical temperature, from AC susceptibility measurements, their values being close to those resulted (at the same temperature and DC field) from the magnetization relaxation data.

17.
Eur Rev Med Pharmacol Sci ; 26(11): 3903-3910, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35731059

RESUMO

OBJECTIVE: We aimed to conduct a review of the literature relevant to cardiac imaging techniques and summarize the use of different non-invasive imaging modalities in the assessment of ventricular size, function, and mechanics. The current review emphasizes the benefits of speckle tracking imaging (STI), highlighting its use in demonstrating myocardial strain. This robust technique is a recent addition to the existing imaging techniques that are used to assess the myocardium. In terms of effectively determining the left ventricle ejection fraction, it is a comparable technique to cardiac magnetic resonance. The use of STI method for image acquisition relies on semiautomatic identification of the border and deformation of the region of interest, and is also independent of the angle of insonation, thus it increases the inter-and intra-observer reproducibility in contrast to the conventional tissue doppler imaging. MATERIALS AND METHODS: The databases of PubMed, Scopus, and Embase were thoroughly searched for the following keywords: 2- dimensional/ two-dimensional/ 2-D, speckle/strain tracking, systolic dysfunction, and heart failure. The studies selected described image acquisition techniques and the application of this imaging modality in various clinical settings. The selected journal articles were perused to provide the best possible analysis of STI. RESULTS: Our comparative analysis demonstrated that the STI, when compared with the conventional echocardiography, is a more sensitive image acquiring technique for detecting subclinical myocardial dysfunction. Based on the analysis it can be stated that the STI can provide valuable information on both regional and global myocardial function, and it can also quantify cardiac synchronicity and rotation. Additionally, it serves as a better prognostic indicator. CONCLUSIONS: The change in longitudinal strain can serve as an early marker of the left ventricular systolic dysfunction, and therefore, monitoring via STI has both diagnostic and prognostic value in heart failure, ischemic heart disease, valvulopathies, chemotherapy-induced cardiotoxicity, and cardiac resynchronization therapy. Despite the lack of standardization, the method is also effective in assessing the right ventricle and left atrial function and arterial rigidity.


Assuntos
Ecocardiografia , Insuficiência Cardíaca , Ecocardiografia/métodos , Insuficiência Cardíaca/diagnóstico por imagem , Ventrículos do Coração/diagnóstico por imagem , Humanos , Prognóstico , Reprodutibilidade dos Testes
18.
Dent Mater ; 38(8): 1261-1270, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35715246

RESUMO

OBJECTIVE: The aim of this study was to assess the accuracy of a Principal Components Analysis (PCA)-based method for reflectance reconstruction and color estimation of layered dental resin-based composites with different thicknesses. METHOD: Bi-layered samples of different clinically relevant thicknesses were created using shades of VITAPAN Excell (VE), VITAPAN Dentine (VD) and VITA Physiodens (VP), combined with their corresponding enamel shades. Spectral reflectance of all samples was measured over a black background using a non-contact spectroradiometer with CIE 45∘∕0∘ geometry. Two different PCA-based models, built from two different configurations of known samples, were proposed to reconstruct the spectral data and color of unknown layered samples. Root Mean Square Error (RMSE), Goodness of Fit (GFC), as well as ΔE00 with corresponding 50:50% acceptability and perceptibly thresholds (AT and PT) were used as performance assessment. RESULTS: The 5-samples training set approach provided an average RMSE < 0.015 and GFC > 0.999 when measured and predicted spectral reflectances were compared, while for the 9-samples training set, RMSE < 0.0098 and GFC > 0.9999 were obtained. The overall mean color differences obtained with the 5-samples training set approach were ΔE00 = 0.99 (AT% = 96.25% and PT% = 32.50%), while using the 9-samples training set resulted in lower overall mean color differences: ΔE00 = 0.50 (AT% = 99.22% and PT% = 83.87%). SIGNIFICANCE: Within the framework of this study, the two proposed PCA-based configurations allow the prediction of the spectral reflectance of layered dental resin-based composites of different shades and thicknesses, with a high degree of accuracy.


Assuntos
Resinas Compostas , Esmalte Dentário , Cor , Teste de Materiais
19.
Nanotechnology ; 22(5): 055204, 2011 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-21178263

RESUMO

We show that thin horizontal arrays of single wall carbon nanotubes (SWNTs) suspended above the channel of silicon MOSFETs can be used as vibrating gate electrodes. This new class of nano-electromechanical system (NEMS) combines the unique mechanical and electronic properties of SWNTs with an integrated silicon-based motion detection. Its electrical response exhibits a clear signature of the mechanical resonance of SWNT arrays (120-150 MHz) showing that these thin horizontal arrays behave as a cohesive, rigid and elastic body membrane with a Young's modulus in the order of 1-10 GPa and ultra-low mass. The resonant frequency can be tuned by the gate voltage and its dependence is well understood within the continuum mechanics framework.

20.
J Hosp Infect ; 114: 153-162, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33932554

RESUMO

AIM: To evaluate the performance of a new catheter design based on different hydrodynamics aiming to reduce the development of biofilm, and compare it with a conventional Foley catheter (FC). METHODS: The new proposed design (NPD) catheter is a modification of the FC, based on asymmetric positioning of the balloon and additional drainage holes allowing continuous urine drainage and complete voiding of the bladder. A first experiment was undertaken to assess drainage capability, and a second experiment was performed using a bioreactor with a set-up simulating the bladder and using the test catheter as a flow-through system. The biofilm formation of five bacterial species associated with catheter-associated urinary tract infection (CAUTI) was determined after 24 h of incubation using an MTT assay. Morphological evaluation was performed using scanning electron microscopy. In-vitro determination of residual fluid, and quantitative and morphological data on biofilm formation on the intravesical and intraluminal parts of the tested catheters were assessed. RESULTS: Residual fluid was significantly higher in the FC (5.60 ± 0.43 mL) compared with the NPD catheter (0.2 ± 0.03 mL). The NPD catheter showed significantly less biofilm formation (P<0.0001) than the FC. Catheter design had a variable effect on biofilm formation depending on the bacterial strain tested. There was significantly less intraluminal biomass compared with intravesical biomass in both catheters (P<0.0001). Multi-layered biofilms that covered the FC surfaces completely were seen for all tested strains, while the NPD catheter surfaces showed reduced biofilm formation. CONCLUSIONS: Modifications of the hydrodynamic characteristics of a catheter can significantly reduce bacterial colonization. Integrated design approaches combining chemical, mechanical and topographical elements can help to reduce the occurrence of CAUTI.


Assuntos
Hidrodinâmica , Infecções Urinárias , Biofilmes , Humanos , Cateterismo Urinário/efeitos adversos , Cateteres Urinários
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