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1.
ACS Omega ; 9(26): 29035-29040, 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38973892

RESUMEN

This study investigates the enantioselectivity challenges of asymmetric cyanation reactions using TADDOL derivatives as chiral ligands, specifically focusing on the cyanosilylation of aldehydes and the cyanation of imines. Despite extensive optimization efforts, the highest achieved ee was only modest, peaking at 71% for the cyanosilylation reaction, while the cyanation of imines consistently resulted in racemic mixtures. Our comprehensive analysis, supported by experimental data and computational modeling, reveals significant barriers to enhancing the enantioselectivity. The results highlight a complex interplay between ligand structure and reaction conditions, demonstrating that even promising ligands such as TADDOL derivatives face substantial challenges in these reaction types. This study underscores the importance of understanding the mechanistic details through computational insights to guide future improvements in asymmetric catalysis.

2.
Bioengineering (Basel) ; 11(6)2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38927819

RESUMEN

Ischemic heart disease remains a leading cause of mortality worldwide, which has promoted extensive therapeutic efforts. Stenting has emerged as the primary intervention, particularly among individuals aged 70 years and older. The geometric specifications of stents must align with various mechanical performance criteria outlined by regulatory agencies such as the Food and Drug Administration (FDA). Finite element method (FEM) analysis and computational fluid dynamics (CFD) serve as essential tools to assess the mechanical performance parameters of stents. However, the growing complexity of the numerical models presents significant challenges. Herein, we propose a method to determine the mechanical performance parameters of stents using a simplified FEM model comprising solid and shell elements. In addition, a baseline model of a stent is developed and validated with experimental data, considering parameters such as foreshortening, radial recoil, radial recoil index, and radial stiffness of stents. The results of the simplified FEM model agree well with the baseline model, decreasing up to 80% in computational time. This method can be employed to design stents with specific mechanical performance parameters that satisfy the requirements of each patient.

3.
RSC Adv ; 14(25): 17710-17723, 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38832247

RESUMEN

Antimicrobial resistance (AMR) represents a critical challenge worldwide, necessitating the pursuit of novel approaches to counteract bacterial and fungal pathogens. In this context, we explored the potential of cationic amino acid-enriched short peptides, synthesized via solid-phase methods, as innovative antimicrobial candidates. Our comprehensive evaluation assessed the antibacterial and antifungal efficacy of these peptides against a panel of significant pathogens, including Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes, Candida albicans, and Aspergillus niger. Utilizing molecular docking techniques, we delved into the molecular interactions underpinning the peptides' action against these microorganisms. The results revealed a spectrum of inhibitory activities, with certain peptide sequences displaying pronounced effectiveness across various pathogens. These findings underscore the peptides' potential as promising antimicrobial agents, with molecular docking offering valuable insights into their mechanisms of action. This study enriches antimicrobial peptide (AMP) research by identifying promising candidates for further refinement and development toward therapeutic application, highlighting their significance in addressing the urgent issue of AMR.

4.
Heliyon ; 10(7): e28482, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38601514

RESUMEN

In recent years, the growth of Internet of Things devices has increased the use of sustainable energy sources. An alternative technology is offered by triboelectric nanogenerators (TENGs) that can harvest green energy and convert it into electrical energy. Herein, we assessed three different nopal powder types that were used as triboelectric layers of eco-friendly and sustainable TENGs for renewable energy harvesting from environmental vibrations and powering electronic devices. These nanogenerators were fabricated using waste and recycled materials with a compact design for easy transportation and collocation on non-homogeneous surfaces of different vibration or motion sources. In addition, these TENGs have advantages such as high output performance, stable output voltage, lightweight, low-cost materials, and a simple fabrication process. These nanogenerators use the contact-separation mode between two triboelectric layers to convert the vibration energy into electrical energy. TENG with the best output performance is based on dehydrated nopal powder, generating an output power density of 2.145 mWm-2 with a load resistance of 39.97 MΩ under 3g acceleration and 25 Hz operating frequency. The proposed TENGs have stable output voltages during 22500 operating cycles. These nanogenerators can light 116 ultra-bright blue commercial LEDs and power a digital calculator. Also, the TENGs can be used as a chess clock connected to a mobile phone app for smart motion sensing. These nanogenerators can harvest renewable vibration energy and power electronic devices, sensors, and smart motion sensing.

5.
Antioxidants (Basel) ; 12(12)2023 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-38136177

RESUMEN

We explored the potential of different nanoparticles (TiO2, CaCO3, and Al2O3), considering their pure form and modified with cinnamon essential oil (CEO). These materials were characterized using various techniques, including FTIR spectroscopy, XRD analysis, TGA, and SEM. The interaction between CEO and nanoparticles changed depending on the nanoparticle type. Al2O3 nanoparticles exhibited the strongest interaction with CEO, increasing their antioxidant capacity by around 40% and their transfer of antimicrobial properties, particularly against Gram-negative bacteria. In contrast, TiO2 and CaCO3 nanoparticles showed limited interaction with CEO, resulting in lower antioxidant capacity and antimicrobial activity. Incorporating pure and CEO-modified nanoparticles into polylactic acid (PLA) films improved their mechanical and thermal properties, which are suitable for applications requiring greater strength. This research highlights the potential of metal oxide nanoparticles to enhance the antimicrobial and antioxidant capabilities of polymers. In addition, incorporating cinnamon essential oil can increase the antioxidant and antimicrobial effectiveness of the metal oxide nanoparticles and improve the mechanical and thermal properties of PLA films. Thus, these PLA films exhibit favorable characteristics for active packaging applications.

6.
Sensors (Basel) ; 23(24)2023 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-38139637

RESUMEN

Microelectromechanical systems (MEMS)-based filter with microchannels enables the removal of various microorganisms, including viruses and bacteria, from fluids. Membranes with porous channels can be used as filtration interfaces in MEMS hemofilters or mini-dialyzers. The main problems associated with the filtration process are optimization of membrane geometry and fouling. A nanoporous aluminum oxide membrane was fabricated using an optimized two-step anodization process. Computational strength modeling and analysis of the membrane with specified parameters were performed using the ANSYS structural module. A fuzzy simulation was performed for the numerical analysis of flux through the membrane. The membrane was then incorporated with the prototype for successive filtration. The fluid flux and permeation analysis of the filtration process have been studied. Scanning electron microscope (SEM) micrographs of membranes have been obtained before and after the filtration cycles. The SEM results indicate membrane fouling after multiple cycles, and thus the flux is affected. This type of fabricated membrane and setup are suitable for the separation and purification of various fluids. However, after several filtration cycles, the membrane was degraded. It requires a prolonged chemical cleaning. High-density water has been used for filtration purposes, so this MEMS-based filter can also be used as a mini-dialyzer and hemofilter in various applications for filtration. Such a demonstration also opens up a new strategy for maximizing filtration efficiency and reducing energy costs for the filtration process by using a layered membrane setup.

7.
RSC Adv ; 13(35): 24250-24263, 2023 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-37583660

RESUMEN

A new library of peptide-heterocycle hybrids consisting of an indole-3-carboxylic acid constituent conjugated with short dipeptide motifs was designed and synthesized by using the solid phase peptide synthesis methodology. All the synthesized compounds were characterized by spectroscopic techniques. Additionally, the synthesized compounds were subjected to in vitro antimicrobial activities. Two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and two Gram-positive (Streptococcus pyogenes and Staphylococcus aureus) were used for the evaluation of the antibacterial activity of the targeted dipeptide derivatives. Good antibacterial activity was observed for the screened analogues by comparing their activities with that of ciprofloxacin, the standard drug. Also, two fungi (Aspergillus niger and Candida albicans) were employed for the evaluation of the antifungal activity of the synthesized compounds. When compared to the standard drug Fluconazole, it was observed that the screened analogues exhibited good antifungal activity. In continuation, all the synthesized derivatives were subjected to integrated molecular docking studies and molecular dynamics simulations to investigate binding affinities, intermolecular interaction networks, and conformational flexibilities with deoxyribonucleic acid (DNA) gyrase and lanosterol-14-alpha demethylase. The molecular docking studies revealed that indole-3-carboxylic acid conjugates exhibited encouraging binding interaction networks and binding affinity with DNA gyrase and lanosterol-14 alpha demethylase to show antibacterial and antifungal activity, respectively. Such synthesis, biological activity, molecular dynamics simulations, and molecular docking studies of short peptides with an indole conjugate unlock the door for the near future advancement of novel medicines containing peptide-heterocycle hybrids with the ability to be effective as antimicrobial agents.

8.
Antioxidants (Basel) ; 12(5)2023 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-37237956

RESUMEN

One of the main causes of food spoilage is the lipid oxidation of its components, which generates the loss of nutrients and color, together with the invasion of pathogenic microorganisms. In order to minimize these effects, active packaging has played an important role in preservation in recent years. Therefore, in the present study, an active packaging film was developed using polylactic acid (PLA) and silicon dioxide (SiO2) nanoparticles (NPs) (0.1% w/w) chemically modified with cinnamon essential oil (CEO). For the modification of the NPs, two methods (M1 and M2) were tested, and their effects on the chemical, mechanical, and physical properties of the polymer matrix were evaluated. The results showed that CEO conferred to SiO2 NPs had a high percentage of 2,2-diphenyl-l-picrylhydrazyl (DPPH) free radical inhibition (>70%), cell viability (>80%), and strong inhibition to E. coli, at 45 and 11 µg/mL for M1 and M2, respectively, and thermal stability. Films were prepared with these NPs, and characterizations and evaluations on apple storage were performed for 21 days. The results show that the films with pristine SiO2 improved tensile strength (28.06 MPa), as well as Young's modulus (0.368 MPa) since PLA films only presented values of 27.06 MPa and 0.324 MPa, respectively; however, films with modified NPs decreased tensile strength values (26.22 and 25.13 MPa), but increased elongation at break (from 5.05% to 10.32-8.32%). The water solubility decreased from 15% to 6-8% for the films with NPs, as well as the contact angle, from 90.21° to 73° for the M2 film. The water vapor permeability increased for the M2 film, presenting a value of 9.50 × 10-8 g Pa-1 h-1 m-2. FTIR analysis indicated that the addition of NPs with and without CEO did not modify the molecular structure of pure PLA; however, DSC analysis indicated that the crystallinity of the films was improved. The packaging prepared with M1 (without Tween 80) showed good results at the end of storage: lower values in color difference (5.59), organic acid degradation (0.042), weight loss (24.24%), and pH (4.02), making CEO-SiO2 a good component to produce active packaging.

9.
Sensors (Basel) ; 23(9)2023 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-37177398

RESUMEN

Triboelectric nanogenerators (TENGs) based on organic materials can harvest green energy to convert it into electrical energy. These nanogenerators could be used for Internet-of-Things (IoT) devices, substituting solid-state chemical batteries that have toxic materials and limited-service time. Herein, we develop a portable triboelectric nanogenerator based on dehydrated nopal powder (NOP-TENG) as novel triboelectric material. In addition, this nanogenerator uses a polyimide film tape adhered to two copper-coated Bakelite plates. The NOP-TENG generates a power density of 2309.98 µW·m-2 with a load resistance of 76.89 MΩ by applying a hand force on its outer surface. Furthermore, the nanogenerator shows a power density of 556.72 µW·m-2 with a load resistance of 76.89 MΩ and under 4g acceleration at 15 Hz. The output voltage of the NOP-TENG depicts a stable output performance even after 27,000 operation cycles. This nanogenerator can light eighteen green commercial LEDs and power a digital calculator. The proposed NOP-TENG has a simple structure, easy manufacturing process, stable electric behavior, and cost-effective output performance. This portable nanogenerator may power electronic devices using different vibration energy sources.

10.
ACS Omega ; 8(51): 48843-48854, 2023 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-38162790

RESUMEN

Peptide synthesis has opened new frontiers in the quest for bioactive molecules with limitless biological applications. This study presents the synthesis of a series of novel isoquinoline dipeptides using advanced spectroscopic techniques for characterization. These compounds were designed with the goal of discovering unexplored biological activities that could contribute to the development of novel pharmaceuticals. We evaluated the biological activities of novel compounds including their antimicrobial, antibacterial, and antifungal properties. The results show promising activity against Escherichia coli and potent antibacterial activity against MTCC 443 and MTCC 1688. Furthermore, these compounds demonstrate strong antifungal activity, outperforming existing standard drugs. Computational binding affinity studies of tetrahydroisoquinoline-conjugated dipeptides against E. coli DNA gyrase displayed significant binding interactions and binding affinity, which are reflected in antimicrobial activities of compounds. Our integrative significant molecular findings from both wet and dry laboratories would help pave a path for the development of antimicrobial therapeutics. The findings suggest that these isoquinoline-conjugated dipeptides could be excellent candidates for drug development, with potential applications in the fight against bacterial and fungal infections. This research represents an exciting step forward in the field of peptide synthesis and its potential to discover novel bioactive molecules with significant implications for human health.

11.
Nanomaterials (Basel) ; 12(24)2022 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-36558257

RESUMEN

The internet of medical things (IoMT) is used for the acquisition, processing, transmission, and storage of medical data of patients. The medical information of each patient can be monitored by hospitals, family members, or medical centers, providing real-time data on the health condition of patients. However, the IoMT requires monitoring healthcare devices with features such as being lightweight, having a long lifetime, wearability, flexibility, safe behavior, and a stable electrical performance. For the continuous monitoring of the medical signals of patients, these devices need energy sources with a long lifetime and stable response. For this challenge, conventional batteries have disadvantages due to their limited-service time, considerable weight, and toxic materials. A replacement alternative to conventional batteries can be achieved for piezoelectric and triboelectric nanogenerators. These nanogenerators can convert green energy from various environmental sources (e.g., biomechanical energy, wind, and mechanical vibrations) into electrical energy. Generally, these nanogenerators have simple transduction mechanisms, uncomplicated manufacturing processes, are lightweight, have a long lifetime, and provide high output electrical performance. Thus, the piezoelectric and triboelectric nanogenerators could power future medical devices that monitor and process vital signs of patients. Herein, we review the working principle, materials, fabrication processes, and signal processing components of piezoelectric and triboelectric nanogenerators with potential medical applications. In addition, we discuss the main components and output electrical performance of various nanogenerators applied to the medical sector. Finally, the challenges and perspectives of the design, materials and fabrication process, signal processing, and reliability of nanogenerators are included.

12.
Nanomaterials (Basel) ; 12(19)2022 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-36234674

RESUMEN

In previous work, the isolated polyphenolic compound (PPC) quercetin was used as a reducing agent in the formation of silver nanoparticles (AgNPs), testing two types of quercetin. This PPC is a bioactive molecule that provides the electrons for the reduction of silver ions to zerovalent silver. The results demonstrated that quercetin in dietary supplement presentation was better than reagent grade quercetin for the synthesis of AgNPs, and the difference between them was that the dietary supplement had microcrystalline cellulose (CM) in its formulation. Therefore, this dietary anti-caking agent was added to the reagent-grade quercetin to validate this previously found improvement. AgNPs were obtained at neutral pH by a green route using quercetin as a reducing agent and microcrystalline cellulose and maltodextrin as stabilizing agents. In addition, different ratios were evaluated to find the optimum ratio. Ultraviolet-Visible spectroscopy (UV-VIS), Atomic Force Microscope (AFM), Z-potential, Dynamic Light Scattering (DLS) and X-ray Powder Diffraction (XRD) were used for characterization. The antibacterial activity of the S. aureus and E. coli agent was tested by the disk diffusion and microdilution method. According to the results, this green synthesis needs the use of food stabilizer when working at pH 7 to maintain AgNPs in the long term. The ideal ratio of reducing the agent:stabilizing agent was 1:2, since with this system stable AgNPs are obtained for 2 months and with improved antimicrobial activity, validating this method was ecologically and economically viable.

13.
Nanomaterials (Basel) ; 12(15)2022 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-35893517

RESUMEN

Natural sources of green energy include sunshine, water, biomass, geothermal heat, and wind. These energies are alternate forms of electrical energy that do not rely on fossil fuels. Green energy is environmentally benign, as it avoids the generation of greenhouse gases and pollutants. Various systems and equipment have been utilized to gather natural energy. However, most technologies need a huge amount of infrastructure and expensive equipment in order to power electronic gadgets, smart sensors, and wearable devices. Nanogenerators have recently emerged as an alternative technique for collecting energy from both natural and artificial sources, with significant benefits such as light weight, low-cost production, simple operation, easy signal processing, and low-cost materials. These nanogenerators might power electronic components and wearable devices used in a variety of applications such as telecommunications, the medical sector, the military and automotive industries, and internet of things (IoT) devices. We describe new research on the performance of nanogenerators employing several green energy acquisition processes such as piezoelectric, electromagnetic, thermoelectric, and triboelectric. Furthermore, the materials, applications, challenges, and future prospects of several nanogenerators are discussed.

14.
Soft Matter ; 17(32): 7476-7486, 2021 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-34291272

RESUMEN

The geometric organization and force networks of 3D dense suspensions that exhibit both shear thinning and thickening have been examined as a function of varying strength of interparticle attractive interactions using lubrication flow discrete element simulations. Significant rearrangement of the geometric topology does not occur at either the local or global scale as these systems transition across the shear thinning and shear thickening regimes. In contrast, massive rearrangements in the balance of attractive, lubrication, and contact forces are observed with interesting behavior of network growth and competition. In agreement with prior work, in shear thinning regions the attractive force is dominant, however as the shear thickening region is approached there is growth of lubrication forces. Lubrication forces oppose the attraction forces, but as viscosity continues to increase under increasing shear stress, the lubrication forces are dominated by contact forces that also resist attraction. Contact forces are the dominant interactions during shear thickening and are an order of magnitude higher than their values in the shear-thinning regime. At high attractive interaction strength, contact networks can form even under shear thinning conditions, however high shear stress is still required before contact networks become the driving mechanism of shear thickening. Analysis of the contact force network during shear thickening generally indicates a uniformly spreading network that rapidly forms across empty domains; however the growth patterns exhibit structure that is significantly dependent upon the strength of interparticle interactions, indicating subtle variations in the mechanism of shear thickening.

15.
J Chem Phys ; 154(11): 114114, 2021 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-33752361

RESUMEN

Encoding the complex features of an energy landscape is a challenging task, and often, chemists pursue the most salient features (minima and barriers) along a highly reduced space, i.e., two- or three-dimensions. Even though disconnectivity graphs or merge trees summarize the connectivity of the local minima of an energy landscape via the lowest-barrier pathways, there is much information to be gained by also considering the topology of each connected component at different energy thresholds (or sublevelsets). We propose sublevelset persistent homology as an appropriate tool for this purpose. Our computations on the configuration phase space of n-alkanes from butane to octane allow us to conjecture, and then prove, a complete characterization of the sublevelset persistent homology of the alkane CmH2m+2 Potential Energy Landscapes (PELs), for all m, in all homological dimensions. We further compare both the analytical configurational PELs and sampled data from molecular dynamics simulation using the united and all-atom descriptions of the intramolecular interactions. In turn, this supports the application of distance metrics to quantify sampling fidelity and lays the foundation for future work regarding new metrics that quantify differences between the topological features of high-dimensional energy landscapes.

16.
J Chem Theory Comput ; 16(7): 4579-4587, 2020 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-32482064

RESUMEN

The structural features that protrude above or below a soft matter interface are well-known to be related to interfacially mediated chemical reactivity and transport processes. It is a challenge to develop a robust algorithm for identifying these organized surface structures, as the morphology can be highly varied and they may exist on top of an interface containing significant interfacial roughness. A new algorithm that employs concepts from geometric measure theory, algebraic topology, and optimization is developed to identify candidate structures at a soft matter surface, and then, using a probabilistic approach, to rank their likelihood of being a complex structural feature. The algorithm is tested for a surfactant laden water/oil interface, where it is robust to identifying protrusions responsible for water transport against a set identified by visual inspection. To our knowledge, this is the first example of applying geometric measure theory to analyze the properties of a chemical/materials science system.

17.
Int J Food Sci Nutr ; 70(7): 856-867, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30892114

RESUMEN

The present study evaluated the effects of blackberry juice that is rich in different concentrations of anthocyanins and polyphenols (2.6 mg/kg anthocyanins, 14.57 mg/kg polyphenols; 5.83 mg/kg anthocyanins, 27.10 mg/kg polyphenols; 10.57 mg/kg anthocyanins, 38.40 mg/kg polyphenols) on anxiety-like behaviour in Wistar rats. The rats were treated with blackberry juice for 21 days and then tested in the elevated plus maze, locomotor activity test and forced swim test. The results were compared with a reference anxiolytic drug diazepam (2.0 mg/kg) and vehicle (8.7 ml/kg). The intermediate dose of blackberry juice exerted an anxiolytic-like effect that was similar to diazepam, without affecting locomotive activity. The low and high doses of blackberry juice exerted no significant effects on anxiety-like behaviour compared with vehicle. In the forced swim test, both the high and intermediate doses of blackberry juice reduced total immobility time, suggesting a protective effect against behavioural changes that are induced by acute stress. These findings suggest a potential therapeutic effect of blackberry juice on anxiety that is associated with a stressful event.


Asunto(s)
Ansiedad/tratamiento farmacológico , Jugos de Frutas y Vegetales , Extractos Vegetales/farmacología , Rubus/química , Animales , Antocianinas/farmacología , Diazepam/farmacología , Locomoción/efectos de los fármacos , Masculino , Modelos Animales , Polifenoles/farmacología , Ratas , Ratas Wistar
18.
World Neurosurg ; 122: e156-e167, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30268546

RESUMEN

BACKGROUND: Anterior cervical discectomy and fusion with a porous tantalum cage is an accepted method to treat degenerated cervical discs, with good results, similar to those with autologous bone graft and plating at short- and mid-term follow-up. However, to date, long-term follow-up studies have been performed. METHODS: We performed a retrospective, single-center study to evaluate the outcomes of 2 cohorts from a previous prospective randomized controlled trial comparing stand-alone tantalum cage (group 1, 27 patients) with autologous bone graft and plating (group 2, 30 patients) for single-level anterior cervical discectomy and fusion at 11 years of follow-up. The usual clinical and radiological outcomes and "overall success," proposed by the Food and Drug Administration, were evaluated. RESULTS: The improvement in clinical outcomes achieved postoperatively was maintained similarly in the 2 cohorts at 11 years of follow-up. In group 1, the cage had subsided 2-3 mm in 12 patients (44%), segmental lordosis was maintained in 16 patients (59%), adjacent segment degeneration had developed or progressed in 27 of the adjacent segments (50%) in 15 patients (56%), and postoperative nonprogressive deformation of the anterior aspect of the cage was observed in 7 (26%) and minor fragmentation in 3 (11%) patients. In group 2, segmental lordosis was maintained in 90% of the patients and adjacent segment degeneration had developed or progressed in 15 patients (50%). CONCLUSIONS: These results show that the clinical and radiological outcomes achieved at mid-term follow-up using a tantalum cage for single-level anterior cervical discectomy and fusion will be maintained for 11 years postoperatively, similar to the results with autologous bone graft and plating.


Asunto(s)
Trasplante Óseo , Vértebras Cervicales/cirugía , Fijación Interna de Fracturas , Degeneración del Disco Intervertebral/cirugía , Fusión Vertebral/métodos , Adulto , Anciano , Vértebras Cervicales/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Humanos , Fijadores Internos , Degeneración del Disco Intervertebral/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Tantalio , Trasplante Autólogo , Resultado del Tratamiento , Adulto Joven
19.
Semin Ultrasound CT MR ; 38(2): 126-142, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28347416

RESUMEN

The purpose of this article is to review the use of ultrasound as a screening tool for spinal diseases in neonates and infants and its intraoperative value in selected pediatric neurosurgical disorders. A review of spinal embryology followed by a description of common spinal diseases in neonates assessed with ultrasound is presented. Indications for spinal ultrasound in neonates, commonly identified conditions, and the importance of magnetic resonance imaging in selected cases are emphasized. Additionally, the use of ultrasound in selected neurosurgical spinal diseases in pediatric patients is presented with magnetic resonance imaging and intraoperative correlation. Technique, limitations, and pitfalls are discussed.


Asunto(s)
Enfermedades del Recién Nacido/diagnóstico por imagen , Enfermedades de la Columna Vertebral/diagnóstico por imagen , Ultrasonografía/métodos , Humanos , Recién Nacido , Columna Vertebral/diagnóstico por imagen
20.
Neuroradiology ; 59(1): 43-50, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27889836

RESUMEN

INTRODUCTION: The purpose of this study was to determine the diagnostic accuracy of synthetic MR sequences generated through post-acquisition processing of a single sequence measuring inherent R1, R2, and PD tissue properties compared with sequences acquired conventionally as part of a routine clinical pediatric brain MR exam. METHODS: Thirty-two patients underwent routine clinical brain MRI with conventional and synthetic sequences acquired (22 abnormal). Synthetic axial T1, T2, and T2 fluid attenuation inversion recovery or proton density-weighted sequences were made to match the comparable clinical sequences. Two exams for each patient were de-identified. Four blinded reviewers reviewed eight patients and were asked to generate clinical reports on each exam (synthetic or conventional) at two different time points separated by a mean of 33 days. Exams were rated for overall and specific finding agreement (synthetic/conventional and compared to gold standard consensus review by two senior reviewers with knowledge of clinical report), quality, and diagnostic confidence. RESULTS: Overall agreement between conventional and synthetic exams was 97%. Agreement with consensus readings was 84% (conventional) and 81% (synthetic), p = 0.61. There were no significant differences in sensitivity, specificity, or accuracy for specific imaging findings involving the ventricles, CSF, brain parenchyma, or vasculature between synthetic or conventional exams (p > 0.05). No significant difference in exam quality, diagnostic confidence, or noise/artifacts was noted comparing studies with synthetic or conventional sequences. CONCLUSIONS: Diagnostic accuracy and quality of synthetically generated sequences are comparable to conventionally acquired sequences as part of a standard pediatric brain exam. Further confirmation in a larger study is warranted.


Asunto(s)
Encefalopatías/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Simulación por Computador , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino
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