Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 200
Filtrer
1.
J Fish Biol ; 105(1): 314-325, 2024 Jul.
Article de Anglais | MEDLINE | ID: mdl-38757464

RÉSUMÉ

Phylogenetic analyses of mitochondrial and nuclear data of 31 specimens of Cyphocharax from trans-Andean rivers support the presence of one lineage of Cyphocharax aspilos in Lago Maracaibo and three cryptic lineages of Cyphocharax magdalenae: (1) Cauca-Magdalena and Ranchería, (2) León and Atrato, and (3) Chucunaque-Tuira, Santa María, and Chiriquí basins of Central America. Results suggest that the Serranía del Perijá facilitated Late Miocene cladogenetic events, whereas post-Isthmian C. magdalenae expansion was enabled by gene flow across the lower Magdalena valley and Central American lowlands. Time-calibrated phylogenetics indicate that the C. magdalenae colonized lower Central America in the Pliocene (3.7 MYA; Ma), the divergence Atrato-Magdalena occurred in Late Pliocene (3.0 Ma) and the split Ranchería-Magdalena during the Middle Pleistocene (1.3 Ma). Updated geographic distribution data support the hypothesis that the Cordillera de Talamanca functions as a barrier to northward expansion of C. magdalenae in Central America.


Sujet(s)
Phylogenèse , Phylogéographie , Rivières , Animaux , Amérique centrale , ADN mitochondrial/génétique , Flux des gènes , Noyau de la cellule/génétique , Analyse de séquence d'ADN
2.
Int Ophthalmol ; 44(1): 215, 2024 May 05.
Article de Anglais | MEDLINE | ID: mdl-38705919

RÉSUMÉ

PURPOSE: There is limited literature on the ocular manifestations in patients with psoriasis. Therefore, this study aimed to identify the prevalence of and factors associated with ocular manifestations in adults with psoriasis. METHODS: This cross-sectional study included Brazilian adults with psoriasis. The dermatological evaluation included diagnosis, clinical form, Psoriasis Area and Severity Index (PASI) measurement, and location of the lesions. Patients underwent a full ophthalmological examination, including the Schirmer I test, Rose Bengala staining, and tear breakup time tests. The results were analyzed using chi-square and Pearson's linear correlation tests. RESULTS: Of the 130 patients assessed, 118 (90.8%) exhibited ocular abnormalities, with meibomian gland dysfunction (MGD) being the most prevalent (59.2%), followed by dry eye disease (DED) (56.2%). A significant correlation was observed between MGD and PASI (p = 0.05), and between MGD and certain treatment modalities. DED was significantly associated with PASI (p < 0.05). Concurrent use of acitretin was identified as an independent predictor of MGD (odds ratio [OR] = 3.5, p < 0.05), whereas PASI was a protective factor against DED (OR = 0.39, p < 0.01). CONCLUSION: Given the high prevalence of eye disease among individuals with psoriasis, routine ophthalmological assessments are recommended to prevent possible ocular complications.


Sujet(s)
Syndromes de l'oeil sec , Psoriasis , Humains , Études transversales , Mâle , Psoriasis/épidémiologie , Psoriasis/complications , Femelle , Brésil/épidémiologie , Adulte , Adulte d'âge moyen , Prévalence , Syndromes de l'oeil sec/épidémiologie , Syndromes de l'oeil sec/étiologie , Syndromes de l'oeil sec/diagnostic , Dysfonctionnement des glandes de Meibomius/épidémiologie , Dysfonctionnement des glandes de Meibomius/diagnostic , Dysfonctionnement des glandes de Meibomius/étiologie , Indice de gravité de la maladie , Sujet âgé , Jeune adulte
3.
Vision (Basel) ; 8(2)2024 May 08.
Article de Anglais | MEDLINE | ID: mdl-38804351

RÉSUMÉ

This study aimed to determine the pars plana length in postmortem human eyes using advanced morphometric techniques and correlate demographics to ocular metrics such as age, sex, ethnicity, and axial length. Between February and July 2005, we conducted a cross-sectional observational study on 46 human cadaver eyes deemed unsuitable for transplant by the SBO Eye Bank. The morphometric analysis was performed on projected images using a surgical microscope and a video-microscopy system with a 20.5:1 correction factor. The pars plana length was measured three times per quadrant, with the final value being the mean of these measurements. Of the 46 eyes collected, 9 were unsuitable for the study due to technical constraints in conducting intraocular measurements. Overall, the average axial length was 25.20 mm. The average pars plana length was 3.8 mm in all quadrants, with no measurements below 2.8 mm or above 4.9 mm. There were no statistically significant variations across quadrants or with age, sex, axial length, or laterality. Accurately defining the pars plana dimensions is crucial for safely accessing the posterior segment of the eye and minimizing complications during intraocular procedures, such as intravitreal injections and vitreoretinal surgeries.

4.
Polymers (Basel) ; 16(8)2024 Apr 12.
Article de Anglais | MEDLINE | ID: mdl-38675000

RÉSUMÉ

Hydrogels are three-dimensional crosslinked materials known for their ability to absorb water, exhibit high flexibility, their biodegradability and biocompatibility, and their ability to mimic properties of different tissues in the body. However, their application is limited by inherent deficiencies in their mechanical properties. To address this issue, reduced graphene oxide (rGO) and tannins (TA) were incorporated into alginate hydrogels (Alg) to evaluate the impact of the concentration of these nanomaterials on mechanical and adhesive, as well as cytotoxicity and wound-healing properties. Tensile mechanical tests demonstrated improvements in tensile strength, elastic modulus, and toughness upon the incorporation of rGO and TA. Additionally, the inclusion of these materials allowed for a greater energy dissipation during continuous charge-discharge cycles. However, the samples did not exhibit self-recovery under environmental conditions. Adhesion was evaluated on pig skin, revealing that higher concentrations of rGO led to enhanced adhesion, while the concentration of TA did not significantly affect this property. Moreover, adhesion remained consistent after 10 adhesion cycles, and the contact time before the separation between the material and the surface did not affect this property. The materials were not cytotoxic and promoted healing in human fibroblast-model cells. Thus, an Alg/rGO/TA hydrogel with enhanced mechanical, adhesive, and wound-healing properties was successfully developed.

5.
Polymers (Basel) ; 16(5)2024 Feb 26.
Article de Anglais | MEDLINE | ID: mdl-38475316

RÉSUMÉ

The mechanical, thermal and gamma radiation attenuation properties of ethylene-propylene-diene monomer (EPDM)-based composites containing graphene nanoplatelets (GNs) and bismuth (III) oxide nanoparticles (B) were investigated. The use of polyethylene glycol (PEG) as a compatibilizer to improve the dispersion of the fillers was also investigated. The results showed that the combined use of these fillers resulted in a drastic increase in mechanical properties, reaching 123% and 83% of tensile strength and elongation at break, respectively, compared to those of EPDM. In contrast, the addition of PEG to composites containing EPDM GNs and B resulted in composites with lower values of mechanical properties compared to the EPDM/B/GN-based composite. However, the presence of PEG leads to obtaining a composite (EPDM/B/GNP) with a mass attenuation coefficient to gamma radiation (137Cs, 662 keV) superior to that composite without PEG. In addition, the composite EPDM, B and PEG exhibited an elongation at break 153% superior to unfilled EPDM. Moreover, the binary filler system consisting of 100 phr of bismuth (III) oxide and 10 phr of GN leads to reaching 61% of the linear damping coefficient of the EPDM composite compared to that value of the unfilled EPDM. The study of the morphology and the state of filler dispersion in the polymer matrix, obtained using scanning electron microscopy and energy-dispersive X-ray spectroscopy, respectively, provides a useful background for understanding the factors affecting the gamma radiation attenuation properties. Finally, the results also indicated that by adjusting the formulation, it is possible to tune the mechanical and thermal properties of EPDM composites reinforced with bismuth oxide and graphene nanoplatelets.

6.
An Acad Bras Cienc ; 95(4): e20190182, 2023.
Article de Anglais | MEDLINE | ID: mdl-38088692

RÉSUMÉ

The present study aimed was to evaluate the spatial variability of weed species by means of phytosociological parameters and their correlations with the physical-chemical soil properties, under semiarid climate conditions. Weed phytosociology and soil characterization were carried out in two areas one newly deforested area covering 8.86 ha, and one experimental agricultural area covering 24.7 ha; both in the semi-arid region of Brazil. Weed and soil were sampled by following georeferenced grids in each area. Biomass and the total number of weed individuals, as well as soil properties, were mapped by the ordinary Kriging method. The predominant herbaceous plants in the newly deforested area were Hexasepalum teres and Digitaria insularis. The weed species that predominated in the agricultural area were Cyperus rotundus L., Euphorbia heterophylla L. and Herissantia Crispa (L.) Brizicky; the latter species outstanding for dry biomass (873.5g). Spatial dependence was observed for the predominant species, except for Digitaria insularis. The spatial distribution of these weeds was conditioned by soil K+ contents in both areas, and by sand content for the experimental agricultural area. Therefore, these two soil attributes resulted key factors for weed infestation in this semi-arid region.


Sujet(s)
Agriculture , Sol , Humains , Sol/composition chimique , Brésil , Agriculture/méthodes , Mauvaises herbes , Biomasse
7.
Rev Sci Instrum ; 94(4)2023 Apr 01.
Article de Anglais | MEDLINE | ID: mdl-38081256

RÉSUMÉ

The characterization of the mechanical behavior of shape memory thin film alloys is essential for their application as microactuators. Depending on the particular application, different elements have been considered for the fabrication of ternary NiTi-based alloys in order to shift the martensitic transformation toward a lower or a higher temperature range. This work presents the design and implementation of a specific device to perform thermal cycles at constant stress on film-like samples over a wide temperature range, between -130 and 300 °C. The uniaxial stress application, the elongations and contractions measurements associated with the martensitic transformations, and the cooling and heating methods are detailed in the present work. The fabrication and operation features of this relatively low cost device facilitate and promote the study of shape memory thin films.

8.
Arch Biochem Biophys ; 750: 109805, 2023 12.
Article de Anglais | MEDLINE | ID: mdl-37913855

RÉSUMÉ

BACKGROUND: The extracellular matrix (ECM) is a complex tridimensional scaffold that actively participates in physiological and pathological events. The objective of this study was to test whether structural proteins of the ECM and glycosaminoglycans (GAGs) may favor the retention of human apolipoprotein A-I (apoA-I) variants associated with amyloidosis and atherosclerosis. METHODS: Biopolymeric matrices containing collagen type I (Col, a main macromolecular component of the ECM) with or without heparin (Hep, a model of GAGs) were constructed and characterized, and used to compare the binding of apoA-I having the native sequence (Wt) or Arg173Pro, a natural variant inducing cardiac amyloidosis. Protein binding was observed by fluorescence microscopy and unbound proteins quantified by a colorimetric assay. RESULTS: Both, Wt and Arg173Pro bound to the scaffolds containing Col, but the presence of Hep diminished the binding efficiency. Col-Hep matrices retained Arg173Pro more than the Wt. The retained protein was only partially removed from the matrices with saline solutions, indicating that electrostatic interactions may occur but are not the main driving force. Using in addition thermodynamic molecular simulations and size exclusion chromatography approaches, we suggest that the binding of apoA-I variants to the biopolymeric matrices is driven by many low affinity interactions. CONCLUSIONS: Under this scenario Col-Hep scaffolds contribute to the binding of Arg173Pro, as a cooperative platform which could modify the native protein conformation affecting protein folding. GENERAL SIGNIFICANCE: We show that the composition of the ECM is key to the protein retention, and well characterized biosynthetic matrices offer an invaluable in vitro model to mimic the hallmark of pathologies with interstitial infiltration such as cardiac amyloidosis.


Sujet(s)
Amyloïdose , Héparine , Humains , Amyloïdose/métabolisme , Apolipoprotéine A-I/génétique , Apolipoprotéine A-I/composition chimique , Collagène/métabolisme , Matrice extracellulaire/métabolisme , Héparine/métabolisme
9.
Eur J Ophthalmol ; : 11206721231204188, 2023 Sep 24.
Article de Anglais | MEDLINE | ID: mdl-37743595

RÉSUMÉ

PURPOSE: To compare the use of toluidine blue 1% eye drops with anterior segment optical coherence tomography (OCT) for the determination of tumour margins in patients with ocular surface squamous neoplasia (OSSN). METHODS: The study was conducted from July 2020 to June 2021 at the Ocular Oncology department at the Federal University of São Paulo, Brazil. Slit-lamp photographs after toluidine blue staining and OCT of the anterior segment were taken on the same day from patients with OSSN. Photographs and OCT images were analyzed quantitatively using the software ImageJ and IMAGEnet®, respectively. The agreement between techniques was evaluated qualitatively through the Bland-Altman graph and quantitatively through intraclass correlation (ICC). RESULTS: A total of 21 participants (71.43% males) with a clinical diagnosis of OSSN were included in the study. The average + SD diameter along the chosen axes was 4.43 ± 2.08 mm with OCT of 4.37 ± 2.03 mm with toluidine blue, a difference not statistically significant (p = 0.2891). The Bland-Altman analysis indicated a good qualitative agreement between the methods, with all cases inserted within the limits of agreement from -0.3217 to 0.4268. The ICC quantitative analysis showed an almost perfect agreement of 99.57% (95%CI: 98.96-99.83%; p < 0.001). CONCLUSIONS: Our findings showed that OCT and toluidine eye drops are equivalent in determining margins for tumour measurements, which is particularly relevant in low-income settings where anterior segment OCT is not available. The use of toluidine blue 1% could be an useful alternative to quantify the size of the tumour, help to monitor tumour growth, and outline margins for surgical planning.

10.
J Phys Chem B ; 127(31): 7018-7026, 2023 Aug 10.
Article de Anglais | MEDLINE | ID: mdl-37498736

RÉSUMÉ

We synthesized the mesoionic compound 2-(4-chlorophenyl)-3-methyl-4-(4-methylphenyl)-1,3-thiazole-5-thiolate and measured its refractive and absorptive nonlinear optical response in different temporal and spectral regimes. The experiments were performed by using the Z-scan technique with two pulsed light sources: the second harmonic (at 532 nm) of a mode-locked and Q-switched Nd-YAG laser (100 ps, 10 Hz) and a Ti: Sapphire laser system (100 fs, 1 kHz) operating at 800 nm. The observation and characterization of nonlinear refraction, two- and three-photon absorption, and excited state absorption of the mesoionic compound dissolved in dimethyl sulfoxide, in different concentrations, are presented and discussed with basis on the population redistribution in a three-energy-level model that allows the determination of the parameters which characterize the nonlinear response.

11.
Front Immunol ; 14: 1174020, 2023.
Article de Anglais | MEDLINE | ID: mdl-37287969

RÉSUMÉ

Objective: To analyze the potential impact of sociodemographic, clinical and biological factors on the long-term cognitive outcome of patients who survived moderate and severe forms of COVID-19. Methods: We assessed 710 adult participants (Mean age = 55 ± 14; 48.3% were female) 6 to 11 months after hospital discharge with a complete cognitive battery, as well as a psychiatric, clinical and laboratory evaluation. A large set of inferential statistical methods was used to predict potential variables associated with any long-term cognitive impairment, with a focus on a panel of 28 cytokines and other blood inflammatory and disease severity markers. Results: Concerning the subjective assessment of cognitive performance, 36.1% reported a slightly poorer overall cognitive performance, and 14.6% reported being severely impacted, compared to their pre-COVID-19 status. Multivariate analysis found sex, age, ethnicity, education, comorbidity, frailty and physical activity associated with general cognition. A bivariate analysis found that G-CSF, IFN-alfa2, IL13, IL15, IL1.RA, EL1.alfa, IL45, IL5, IL6, IL7, TNF-Beta, VEGF, Follow-up C-Reactive Protein, and Follow-up D-Dimer were significantly (p<.05) associated with general cognition. However, a LASSO regression that included all follow-up variables, inflammatory markers and cytokines did not support these findings. Conclusion: Though we identified several sociodemographic characteristics that might protect against cognitive impairment following SARS-CoV-2 infection, our data do not support a prominent role for clinical status (both during acute and long-stage of COVID-19) or inflammatory background (also during acute and long-stage of COVID-19) to explain the cognitive deficits that can follow COVID-19 infection.


Sujet(s)
COVID-19 , Dysfonctionnement cognitif , Adulte , Humains , Femelle , Adulte d'âge moyen , Sujet âgé , Mâle , SARS-CoV-2 , Syndrome de post-COVID-19 , Dysfonctionnement cognitif/épidémiologie , Cytokines
12.
Biochim Biophys Acta Biomembr ; 1865(7): 184176, 2023 10.
Article de Anglais | MEDLINE | ID: mdl-37328024

RÉSUMÉ

Cells are constantly adapting to maintain their identity in response to the surrounding media's temporal and spatial heterogeneity. The plasma membrane, which participates in the transduction of external signals, plays a crucial role in this adaptation. Studies suggest that nano and micrometer areas with different fluidities at the plasma membrane change their distribution in response to external mechanical signals. However, investigations linking fluidity domains with mechanical stimuli, specifically matrix stiffness, are still in progress. This report tests the hypothesis that the stiffness of the extracellular matrix can modify the equilibrium of areas with different order in the plasma membrane, resulting in changes in overall membrane fluidity distribution. We studied the effect of matrix stiffness on the distribution of membrane lipid domains in NIH-3 T3 cells immersed in matrices of varying concentrations of collagen type I, for 24 or 72 h. The stiffness and viscoelastic properties of the collagen matrices were characterized by rheometry, fiber sizes were measured by Scanning Electron Microscopy (SEM) and the volume occupied by the fibers by second harmonic generation imaging (SHG). Membrane fluidity was measured using the fluorescent dye LAURDAN and spectral phasor analysis. The results demonstrate that an increase in collagen stiffness alters the distribution of membrane fluidity, leading to an increasing amount of the LAURDAN fraction with a high degree of packing. These findings suggest that changes in the equilibrium of fluidity domains could represent a versatile and refined component of the signal transduction mechanism for cells to respond to the highly heterogeneous matrix structural composition. Overall, this study sheds light on the importance of the plasma membrane's role in adapting to the extracellular matrix's mechanical cues.


Sujet(s)
Laurate , Fluidité membranaire , Membrane cellulaire/métabolisme , Laurate/composition chimique , Collagène/métabolisme
13.
Toxins (Basel) ; 15(5)2023 04 28.
Article de Anglais | MEDLINE | ID: mdl-37235348

RÉSUMÉ

Envenomation caused by venomous animals may trigger significant local complications such as pain, edema, localized hemorrhage, and tissue necrosis, in addition to complications such as dermonecrosis, myonecrosis, and even amputations. This systematic review aims to evaluate scientific evidence on therapies used to target local effects caused by envenomation. The PubMed, MEDLINE, and LILACS databases were used to perform a literature search on the topic. The review was based on studies that cited procedures performed on local injuries following envenomation with the aim of being an adjuvant therapeutic strategy. The literature regarding local treatments used following envenomation reports the use of several alternative methods and/or therapies. The venomous animals found in the search were snakes (82.05%), insects (2.56%), spiders (2.56%), scorpions (2.56%), and others (jellyfish, centipede, sea urchin-10.26%). In regard to the treatments, the use of tourniquets, corticosteroids, antihistamines, and cryotherapy is questionable, as well as the use of plants and oils. Low-intensity lasers stand out as a possible therapeutic tool for these injuries. Local complications can progress to serious conditions and may result in physical disabilities and sequelae. This study compiled information on adjuvant therapeutic measures and underscores the importance of more robust scientific evidence for recommendations that act on local effects together with the antivenom.


Sujet(s)
Morsures de serpent , Araignées , Animaux , Sérums antivenimeux/usage thérapeutique , Serpents , Scorpions , Insectes , Morsures de serpent/traitement médicamenteux
15.
Vision (Basel) ; 7(2)2023 Apr 23.
Article de Anglais | MEDLINE | ID: mdl-37218954

RÉSUMÉ

Biomechanics is a branch of biophysics that deals with mechanics applied to biology. Corneal biomechanics have an important role in managing patients with glaucoma. While evidence suggests that patients with thin and stiffer corneas have a higher risk of developing glaucoma, it also influences the accurate measurement of intraocular pressure. We reviewed the pertinent literature to help increase our understanding of the biomechanics of the cornea and other ocular structures and how they can help optimize clinical and surgical treatments, taking into consideration individual variabilities, improve the diagnosis of suspected patients, and help monitor the response to treatment.

16.
Clin Cosmet Investig Dermatol ; 16: 697-704, 2023.
Article de Anglais | MEDLINE | ID: mdl-36987400

RÉSUMÉ

Background: There is substantial interpersonal variation in the patterns of muscular contraction that substantiates the use of personalized points of application and dosages in clinical practice to achieve optimal results. Nevertheless, there has been no real-life therapeutic series with botulinum toxin for aesthetic treatment of the face in which the subjects were systematically followed to assess its long-term benefit. Purpose: To assess the performance and length of the treatment of glabellar and forehead lines with IncobotulinumtoxinA in a real-life setting. Patients and Methods: We enrolled 20 adults with indications for the treatment of upper facial dynamic lines (glabella and forehead) with botulinum toxin. The protocols of injection points were personalized by the injectors. The participants were photographed under maximum facial contraction before the application (D0) and after 15, 90, 120, and 180 days. The photos were randomly assessed by two blinded experienced raters to consensually grade the dynamic lines according to the Merz Aesthetics Scales (MAS). Efficacy was defined as the reduction in the MAS score. Results: At D15, 18 (90%; 95% CI: 80%-100%) participants reached the zero score, or a 2-point reduction on the MAS score from the forehead and 16 (80%; 95% CI: 65-90%) reached that reduction for the glabella. These values from D90 were 14 (70%; 95% CI: 55-85%) for both sites. At D120, these values were 11 (55%; 95% CI: 35-75%) and 8 (40%; 95% CI: 25-55%) for the forehead and glabella. At D180, 10 (50%; 95% CI: 30-70%) participants presented a MAS score for forehead or glabella dynamic lines lower than the score assessed at D0. Conclusion: As much as 70% of the patients sustained a reduction of scores after 120 days of the treatment for dynamic glabellar and forehead lines. Half of the patients evidenced prolonged benefit at 180 days.

17.
Rev. méd. hered ; 34(1): 47-53, ene. - mar. 2023. ilus
Article de Anglais | LILACS, LIPECS | ID: biblio-1442076

RÉSUMÉ

SUMMARY The pandemic caused by the COVID-19 has influenced peoples' lifestyles. Home-confinement scenario might impair physical activity practice, resulting in new challenges for maintaining health during the pandemic of the COVID-19. The aim of this study was to present the current context of COVID-19 pandemic, its impact on the practice of physical activity, and the strategies available to remain active during home-confinement according to international recommendations. The narrative review was conducted based on studies that analyzed themes related to physical activity and COVID-19. Virtual Health Library (VHL), CINAHL, Cochrane, PsycINFO, PubMed, ScienceDirect, Scientific Electronic Library Online (SciELO), Scopus, SPORTDiscus, and Web of Science databases were searched for relevant papers. Although an increased number of experimental studies are still necessary, people should devote more time to physical activity during social isolation. Guidelines were adjusted by international entities in order to encourage people to remain active, through practice regular physical activity, using alternative strategies such as fitness program applications, exergames, online exercise classes, and even chores. Reduction of prolonged sedentary behavior could contribute to maintain health and improve quality of life during the COVID-19 pandemic.


La pandemia provocada por la Covid-19 ha influido en los estilos de vida de las personas. El escenario de confinamiento domiciliario podría perjudicar la práctica de actividad física, generando nuevos desafíos para el mantenimiento de la salud durante la pandemia de la Covid-19. El objetivo de este estudio fue presentar el contexto actual de la pandemia de Covid-19, su impacto en la práctica de actividad física y las estrategias disponibles para mantenerse activo durante el confinamiento domiciliario según las recomendaciones internacionales. La revisión narrativa se realizó con base en estudios que analizaron temas relacionados con la actividad física y la Covid-19. Se realizaron búsquedas de artículos relevantes en las bases de datos Virtual Health Library (BVS), CINAHL, Cochrane, PsycINFO, PubMed, ScienceDirect, Scientific Electronic Library Online (SciELO), Scopus, SPORTDiscus y Web of Science. Aunque todavía es necesario un mayor número de estudios experimentales, las personas deberían dedicar más tiempo a la actividad física durante el aislamiento social. Las pautas fueron ajustadas por entidades internacionales para alentar a las personas a mantenerse activas, mediante la práctica de actividad física regular, utilizando estrategias alternativas como aplicaciones de programas de acondicionamiento físico, exergames, clases de ejercicios en línea e incluso tareas domésticas. La reducción del sedentarismo prolongado podría contribuir a mantener la salud y mejorar la calidad de vida durante la pandemia de Covid-19.


Sujet(s)
Humains , Isolement social , Exercice physique , Santé , Infections à coronavirus , Revue de la littérature
18.
J Mater Chem B ; 11(9): 1987-1997, 2023 03 01.
Article de Anglais | MEDLINE | ID: mdl-36752559

RÉSUMÉ

The size and shape of nanoparticles have a profound effect on the properties of nanocomposites. For instance, the lateral dimensions of graphene oxide (GO) platelets affect several properties, including their antibacterial and pharmacokinetic functions. However, the impact of lateral dimensions has been poorly studied in nanocomposites, and their effect on hydrogels is still unknown. The current study aims to determine the effect of GO lateral dimensions on the mechanical, rheological, thermal, and antibacterial properties of gelatin hydrogels. The hydrogels were fabricated via photopolymerization of methacrylated gelatin and GO derived from the oxidation of commercial graphene. The observations indicate that an increase in GO sheets improves the mechanical strength with an increase in compressive modulus and a low mechanical hysteresis (<10%). Furthermore, low mechanical energy is dissipated even after several deformation cycles. The nanocomposite hydrogels demonstrated bactericidal effects on two clinical strains with an extensively drug-resistant phenotype, primarily through contact. Additionally, an increment in lateral dimensions increased the bactericidal capacity of Gram-negative strains. Thus, the significant effect of the lateral dimensions of GO sheets on the properties of hydrogels is demonstrated.


Sujet(s)
Gélatine , Graphite , Nanogels , Hydrogels , Antibactériens
19.
PLoS One ; 18(2): e0271572, 2023.
Article de Anglais | MEDLINE | ID: mdl-36730265

RÉSUMÉ

The hepatic diseases are extremely common in clinical practice. The correct classification of liver fibrosis is extremely important, as it influences therapy and predicts disease outcomes. The purpose of this study is to compare the diagnostic performance of point-shear wave elastography (pSWE) and magnetic resonance elastography (MRE) in the hepatic fibrosis diagnostic. A meta-analysis was carried out based on articles published until October 2020. The articles are available at following databases: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Scientific Electronic Library Online, LILACS, Scopus, and CINAHL. Diagnostic performances were analyzed per METAVIR F2, using 3.5kPa as target fibrosis. Assessment of the methodological quality of the incorporated papers by the QUADAS-2 tool for pSWE and MRE. A total 2,153 studies articles were evaluated and 44 studies, comprising 6,081 patients with individual data, were included in the meta-analysis: 28 studies for pSWE and 16 studies for MRE. The pooled sensitivity and specificity were 0.86 (95%CI 0.80-0.90) and 0.88 (95%CI 0.85-0.91), respectively, for pSWE, compared with 0.94 (95%CI 0.89-0.97) and 0.95 (95%CI 0.89-0.98) respectively, for MRE. The pooled SROC curve for pSWE shows in the area under the curve (AUC) of 0.93 (95%CI 0.90-0.95), whereas the AUC for MRE was 0.98 (95%CI 0.96-0.99). The diagnostic odds ratio for pSWE and MRE were 41 (95%CI 24-72) and 293 (95%CI 86-1000), respectively. There was statistically significant heterogeneity for pSWE sensitivity (I² = 85.26, P<0.001) and specificity (I² = 89.46, P<0.001). The heterogeneity for MRE also was significant for sensitivity (I² = 73.28, P<0.001) and specificity (I² = 87.24, P<0.001). Therefore, both pSWE and MRE are suitable modalities for assessing liver fibrosis. In addition, MRE is a more accurate imaging technique than pSWE and can be used as alternative to invasive biopsy.


Sujet(s)
Imagerie d'élasticité tissulaire , Maladies du foie , Humains , Imagerie d'élasticité tissulaire/méthodes , Cirrhose du foie/imagerie diagnostique , Cirrhose du foie/anatomopathologie , Maladies du foie/anatomopathologie , Sensibilité et spécificité , Biopsie , Foie/imagerie diagnostique , Foie/anatomopathologie
20.
Int J Cardiovasc Imaging ; 39(5): 929-937, 2023 May.
Article de Anglais | MEDLINE | ID: mdl-36680683

RÉSUMÉ

We aimed to evaluate the reasons for disagreement between screening echocardiography (echo), acquired by nonexperts, and standard echo in the Brazilian primary care (PC). Over 20 months, 22 PC workers were trained on simplified handheld (GE VSCAN) echo protocols. Screening groups, consisting of patients aged 17-20, 35-40 and 60-65 years, and patients referred for clinical indications underwent focused echo. Studies were remotelyinterpreted in US and Brazil, and those diagnosed with major or severe HD were referred for standard echoperformed by an expert. Major HD was defined as moderate to severe valve disease, ventriculardysfunction/hypertrophy, pericardial effusion or wall-motion abnormalities. A random sample of exams wasselected for evaluation of variables accounting for disagreement. A sample of 768 patients was analyzed, 651(85%) in the referred group. Quality issues were reported in 5.8%, and the random Kappa for major HD between screening and standard echo was 0.51. The most frequent reasons for disagreement were: overestimation of mitral regurgitation (MR) (17.9%, N=138), left ventricular (LV) dysfunction (15.7%, N=121), aortic regurgitation (AR) (15.2%, N=117), LV hypertrophy (13.5%, N=104) and tricuspid regurgitation (12.7%, N=98). Misdiagnosis of mitral and aortic morphological abnormalities was observed in 12.4% and 3.0%, and underestimation of AR and MR occurred in 4.6% and 11.1%. Among 257 patients with suspected mild/moderate MR, 129 were reclassified to normal. In conclusion, although screening echo with task-shifting in PC is a promising tool in low-income areas, estimation of valve regurgitation and LV function and size account for considerable disagreement with standard exams.


Sujet(s)
Insuffisance aortique , Insuffisance mitrale , Dysfonction ventriculaire gauche , Humains , Échocardiographie/méthodes , Valeur prédictive des tests , Insuffisance mitrale/imagerie diagnostique , Hypertrophie ventriculaire gauche/imagerie diagnostique , Dysfonction ventriculaire gauche/imagerie diagnostique , Soins de santé primaires
SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE