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1.
Annu Int Conf IEEE Eng Med Biol Soc ; 2022: 3854-3857, 2022 07.
Article in English | MEDLINE | ID: mdl-36086471

ABSTRACT

Neuroblastoma (NB) is the most common extracranial solid tumor in childhood. Genomic amplification of MYCN is associated with poor outcomes and is detected in 16% of all NB cases. CT scans and MRI are the imaging techniques recommended for diagnosis and disease staging. The assessment of imaging features such as tumor volume, shape, and local extension represent relevant prognostic information. Radiogenomics have shown powerful results in the assessment of the genotype based on imaging findings automatically extracted from medical images. In this work, random forest was used to classify the MYCN amplification using radiomic features extracted from CT slices in a population of 46 NB patients. The learning model showed an area under the curve (AUC) of 0.85 ± 0.13, suggesting that radiomic-based methodologies might be helpful in the extraction of information that is not accessible by human naked eyes but could aid the clinicians on the diagnosis and treatment plan definition. Clinical relevance - This approach represents a random forest-based model to predict the MYCN amplification in NB patients that could give a faster, earlier, and repeatable analysis of the tumor along the time.


Subject(s)
Neuroblastoma , Area Under Curve , Humans , N-Myc Proto-Oncogene Protein/genetics , N-Myc Proto-Oncogene Protein/metabolism , Neuroblastoma/diagnostic imaging , Neuroblastoma/genetics , Tomography, X-Ray Computed
2.
Carbohydr Polym ; 282: 119058, 2022 Apr 15.
Article in English | MEDLINE | ID: mdl-35123734

ABSTRACT

Driven by the environmental stress caused by plastics, the interest on eco-friendly polymers has attracted the attention of researchers and industry. Thermoplastic starch (TPS) and poly (ε-caprolactone) (PCL) blends are good examples of sustainable material, exhibiting synergism between economic viability and properties. However, its biodegradability aligned to nutrients release has been less explored in agricultural applications. Herein, it is proposed the investigation of biodegradability of urea plasticized TPS and PCL blends, compatibilized with PCL grafted with maleic anhydride (PCL-g-MA), aiming fertilizers and sustainable agricultural products. The blends were prepared in a twin-screw extruder using a flat film die. The mechanical, thermal, morphological, and physical properties of TPS-PCL films were characterized, including biodegradation analysis via Bartha respirometer and nitrogen release in the soil. The films presented biodegradability and nitrogen release as a function of TPS content on blends formulation, presenting flexibility and robust mechanical properties. These findings may open a way of multifunctional agricultural products applied as fertilizer materials through economical and sustainable mulching films.

3.
ACS Appl Mater Interfaces ; 13(22): 26237-26246, 2021 Jun 09.
Article in English | MEDLINE | ID: mdl-34038087

ABSTRACT

Renewable cellulose substrates with submicron- and nanoscale structures have revived interest in paper electronics. However, the processes behind their production are still complex and time- and energy-consuming. Besides, the weak electrolytic properties of cellulose with submicron- and nanoscale structures have hindered its application in transistors and integrated circuits with low-voltage operation. Here, we report a simple, low-cost approach to produce flexible ionic conductive cellulose mats using solution blow spinning, which are used both as dielectric interstrate and substrate in low-voltage devices. The electrochemical properties of the cellulose mats are tuned through infiltration with alkali hydroxides (LiOH, NaOH, or KOH), enabling their application as dielectric and substrate in flexible, low-voltage, oxide-based field-effect transistors and pencil-drawn resistor-loaded inverters. The transistors exhibit good transistor performances under operation voltage below 2.5 V, and their electrical performance is strictly related to the type of alkali ionic specie incorporated. Devices fabricated on K+-infiltrated cellulose mats present the best characteristics, indicating pure capacitive charging of the semiconductor. The pencil-drawn load resistor inverter presents good dynamic performance. These findings may pave the way for a new generation of low-power, wearable electronics, enabling concepts such as the "Internet of Things".

4.
Chem Biodivers ; 16(9): e1900275, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31407869

ABSTRACT

The açaí fruit depulping produces large amounts of long lignocellulosic fiber bundles that are disposed in the environment. Chemical pretreatments may improve açaí fibers favoring their usage in advanced materials. This work aimed to define optimal alkali reaction parameters to improve the properties of açaí fibers. Two NaOH concentrations (5 % and 10 %) and two reaction temperatures (80 °C and 100 °C) were tested. The raw and treated fibers were analyzed by scanning electron microscopy, Fourier transformed infrared spectroscopy, X-ray diffraction, and thermal analyses. All the alkali pretreatments separated fibers from the bundles, unblocked pit channels by removing silicon structures, exposed the inner lignin, partially removed non-cellulosic compounds, and raised the cellulose crystalline index. The highest temperature and NaOH content resulted in better cleaning and isolation of the fibers, while milder conditions better preserved the cellulose crystalline structure and thermal stability.


Subject(s)
Lignin/chemistry , Sodium Hydroxide/chemistry , Lignin/isolation & purification , Particle Size , Surface Properties , Temperature
5.
3 Biotech ; 9(4): 145, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30944792

ABSTRACT

The effect of silver nanoparticles (AgNPs) on plant cells, since their phytotoxicity potential is not yet fully understood. In this context, the aim of the present study was to elucidate the effects of AgNPs in the in vitro culture of Physalis peruviana. For this purpose, P. peruviana seeds were grown in MS medium supplemented with different concentrations of AgNPs. Growth and development of seedlings were evaluated through germination, seedling size and biomass and biochemical and anatomical analyses. At the end of 60 days of cultivation, it was observed that the in vitro germination of this species is not affected by the presence of AgNPs and that at low concentrations (0.385 mg L-1) it can promote an increase in seedlings biomass. However, higher concentration (15.4 mg L-1) leads to a reduction in seedling size and root system, but no changes were observed in the seedlings antioxidant metabolism and anatomy. These results demonstrate that the phytotoxicity of AgNPs in P. peruviana is related to the concentration of nanoparticles to which the specie is exposed.

6.
J Sleep Res ; 28(3): e12637, 2019 06.
Article in English | MEDLINE | ID: mdl-29171171

ABSTRACT

Sleep restriction degrades cognitive and motor performance, which can adversely impact job performance and increase the risk of accidents. Military personnel are prone to operating under sleep restriction, and previous work suggests that military marksmanship may be negatively affected under such conditions. Results of these studies, however, are mixed and have often incorporated additional stressors (e.g. energy restriction) beyond sleep restriction. Moreover, few studies have investigated how the degree of difficulty of a marksmanship task impacts performance following sleep restriction. The purpose of the current experiment was to study the effects of sleep restriction on marksmanship while minimizing the potential influence of other forms of stress. A friend-foe discrimination challenge with greater or lesser degrees of complexity (high versus low load) was used as the primary marksmanship task. Active duty Soldiers were recruited, and allowed 2 h of sleep every 24 h over a 72-h testing period. Marksmanship tasks, cognitive assessment metrics and the NASA-Task Load Index were administered daily. Results indicated that reaction times to shoot foe targets and signal friendly targets slowed over time. In addition, the ability to correctly discriminate between friend and foe targets significantly decreased in the high-cognitive-load condition over time despite shot accuracy remaining stable. The NASA-Task Load Index revealed that, although marksmanship performance degraded, participants believed their performance did not change over time. These results further characterize the consequences of sleep restriction on marksmanship performance and the perception of performance, and reinforce the importance of adequate sleep among service members when feasible.


Subject(s)
Cognition/physiology , Reaction Time/physiology , Sleep Deprivation/psychology , Task Performance and Analysis , Adult , Decision Making , Humans , Male , Military Personnel
7.
Carbohydr Polym ; 181: 1093-1101, 2018 Feb 01.
Article in English | MEDLINE | ID: mdl-29253936

ABSTRACT

A wide variety of new green materials such as curaua leaf fibers (CLFs) has potential applications in nanotechnology. This study aims to investigate the thermomechanical properties and morphological structure of cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) films obtained by continuous casting. The CNCs were obtained by acid hydrolysis and CNFs by mechanical shearing from bleached CLFs and eucalyptus pulp. The morphology after continuous casting resulted in oriented nanofibers, and as a consequence there was mechanical anisotropy. CNCs films showed the greatest values of tensile strength (36±4MPa) and the more effective fibrillation provided better mechanical strength of eucalyptus CNFs films than curaua CNFs films. Sulfur groups and mechanical shear degradation affected the stability of CNCs and CNFs films, respectively. Thus, the type of nanostructure, the way they interact to each other, the cellulose source and the process interfere significantly on the properties of the films.

8.
Sports Health ; 8(6): 507-513, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27789871

ABSTRACT

BACKGROUND: Musculoskeletal injury is a significant threat to readiness in the US Army. Current injury surveillance methods are constrained by accurate injury reporting. Input into electronic medical records or databases therefore may not accurately reflect injury incidence. The purpose of this study was to evaluate injury reporting among active-duty US Army soldiers to explore potential limitations of surveillance approaches. HYPOTHESIS: A significant number of injuries go unreported to medical personnel. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: Level 4. METHODS: Surveys were completed by soldiers assigned to an Army Infantry Brigade Combat Team. Survey questions inquired about injuries sustained in the previous 12 months, injury onset, and whether injuries were reported to a medical provider. Participants were asked to rank reasons for accurately reporting, underreporting, and/or exaggerating injuries. Chi-square analyses were used to compare differences among underreported injuries in terms of injury onset (gradual vs acute) and sex. RESULTS: A total of 1388 soldiers reported 3202 injuries that had occurred in the previous 12-month period, including 1636 (51%) that were reported and 1566 (49%) that were identified as not reported to medical personnel. More than 49% of reported injuries were described as acute and 51% were described as chronic. Injury exaggeration was reported by 6% of soldiers. The most common reasons for not reporting injuries were fear that an injury might affect future career opportunities and avoidance of military "profiles" (mandated physical restrictions). CONCLUSION: Approximately half of musculoskeletal injuries in a Brigade Combat Team were not reported. CLINICAL RELEVANCE: Unreported and untreated injuries can lead to reinjury, chronic pain, performance decrements, and increased costs associated with disability benefits. Additionally, unreported injuries can undermine injury surveillance efforts aimed at reducing the musculoskeletal injury problem in the military.


Subject(s)
Disclosure , Military Personnel/psychology , Musculoskeletal System/injuries , Adolescent , Adult , Cross-Sectional Studies , Female , Humans , Incidence , Male , United States/epidemiology , Young Adult
9.
Phys Ther ; 93(9): 1185-96, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23162043

ABSTRACT

BACKGROUND: The risk of traumatic brain injury (TBI) and comorbid posttraumatic dizziness is elevated in military operational environments. Sleep deprivation is known to affect a service member's performance while deployed, although little is known about its effects on vestibular function. Recent findings suggest that moderate acceleration step rotational stimuli may elicit a heightened angular vestibulo-ocular reflex (aVOR) response relative to low-frequency sinusoidal stimuli after 26 hours of sleep deprivation. There is concern that a sleep deprivation-mediated elevation in aVOR function could confound detection of comorbid vestibular pathology in service members with TBI. The term "dynamic visual acuity" (DVA) refers to an individual's ability to see clearly during head movement and is a behavioral measure of aVOR function. The Dynamic Visual Acuity Test (DVAT) assesses gaze instability by measuring the difference between head-stationary and head-moving visual acuity. OBJECTIVE: The purpose of this study was to investigate the effects of 26 hours of sleep deprivation on DVA as a surrogate for aVOR function. DESIGN: This observational study utilized a repeated-measures design. METHODS: Twenty soldiers with no history of vestibular insult or head trauma were assessed by means of the DVAT at angular head velocities of 120 to 180°/s. Active and passive yaw and pitch impulses were obtained before and after sleep deprivation. RESULTS: Yaw DVA remained unchanged as the result of sleep deprivation. Active pitch DVA diminished by -0.005 LogMAR (down) and -0.055 LogMAR (up); passive pitch DVA was degraded by -0.06 LogMAR (down) and -0.045 LogMAR (up). LIMITATIONS: Sample homogeneity largely confounded accurate assessment of test-retest reliability in this study, resulting in intraclass correlation coefficients lower than those previously reported. CONCLUSIONS: Dynamic visual acuity testing in soldiers who are healthy revealed no change in gaze stability after rapid yaw impulses and subclinical changes in pitch DVA after sleep deprivation. Findings suggest that DVA is not affected by short-term sleep deprivation under clinical conditions.


Subject(s)
Military Personnel , Reflex, Vestibulo-Ocular/physiology , Sleep Deprivation/physiopathology , Visual Acuity/physiology , Adolescent , Adult , Analysis of Variance , Brain Injuries/physiopathology , Female , Humans , Male , Prospective Studies , Reproducibility of Results , Vision Tests
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