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1.
Arch Acad Emerg Med ; 13(1): e3, 2025.
Artículo en Inglés | MEDLINE | ID: mdl-39318866

RESUMEN

Introduction: Foreign body aspiration (FBA) is a common, life-threatening pediatric emergency and was shown to be associated with high risk of morbidity and mortality. This systematic review and meta-analysis aimed to investigate the diagnostic value of chest computed tomography (CT) scan for identification of FBA in children. Methods: From inception to May 2024, a systematic search was carried out across multiple databases including Medline, Scopus, and Web of Science, considering published papers in English language. Quality assessment of the included studies was performed using seven domains of Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). Results: The systematic literature search yielded 7203 articles. The pooled sensitivity and specificity of chest CT scan for identification of FBA were 0.99 (95% CI: 0.98-0.99) and 0.97 (95% CI: 0.96-0.98), respectively. The pooled positive likelihood ratio was 10.12 (95% CI: 4.59-22.20), and pooled negative likelihood ratio was 0.05 (95% CI: 0.02-0.1). Furthermore, the area under the summarized receiver operating characteristic (SROC) curve was 0.98. Conclusion: Our meta-analysis revealed that despite high heterogeneity, in the diagnostic characteristics of chest CT scan among studies, it has high diagnostic value in identifying FBA in suspected pediatric cases.

2.
Artículo en Inglés | MEDLINE | ID: mdl-39011510

RESUMEN

Objectives: Blister pack (BP) ingestion poses serious risks, such as gastrointestinal perforation, and accurate localization by computed tomography (CT) is a common practice. However, while it has been reported in vitro that CT visibility varies with the material type of BPs, there have been no reports on this variability in clinical settings. In this study, we investigated the CT detection rates of different BPs in clinical settings. Methods: This single-center retrospective study from 2010 to 2022 included patients who underwent endoscopic foreign body removal for BP ingestion. The patients were categorized into two groups for BP components, the polypropylene (PP) and the polyvinyl chloride (PVC)/polyvinylidene chloride (PVDC) groups. The primary outcome was the comparison of CT detection rates between the groups. We also evaluated whether the BPs contained tablets and analyzed their locations. Results: This study included 61 patients (15 in the PP group and 46 in the PVC/PVDC group). Detection rates were 97.8% for the PVC/PVDC group compared to 53.3% for the PP group, a significant difference (p < 0.01). No cases of BPs composed solely of PP were detected by CT. Blister packs were most commonly found in the upper thoracic esophagus. Conclusions: Even in a clinical setting, the detection rates of PVC and PVDC were higher than that of PP alone. Identifying PP without tablets has proven challenging in clinical. Considering the risk of perforation, these findings suggest that esophagogastroduodenoscopy may be necessary, even if CT detection is negative.

3.
Biomaterials ; 313: 122814, 2025 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-39243672

RESUMEN

Radiotherapy as a mainstay of in-depth cervical cancer (CC) treatment suffers from its radioresistance. Radiodynamic therapy (RDT) effectively reverses radio-resistance by generating reactive oxygen species (ROS) with deep tissue penetration. However, the photosensitizers stimulated by X-ray have high toxicity and energy attenuation. Therefore, X-ray responsive diselenide-bridged mesoporous silica nanoparticles (DMSNs) are designed, loading X-ray-activated photosensitizer acridine orange (AO) for spot blasting RDT like Trojan-horse against radio-resistance cervical cancer (R-CC). DMSNs can encapsulate a large amount of AO, in the tumor microenvironment (TME), which has a high concentration of hydrogen peroxide, X-ray radiation triggers the cleavage of diselenide bonds, leading to the degradation of DMSNs and the consequent release of AO directly at the tumor site. On the one hand, it solves the problems of rapid drug clearance, adverse distribution, and side effects caused by simple AO treatment. On the other hand, it fully utilizes the advantages of highly penetrating X-ray responsive RDT to enhance radiotherapy sensitivity. This approach results in ROS-induced mitochondria damage, inhibition of DNA damage repair, cell cycle arrest and promotion of cancer cell apoptosis in R-CC. The X-ray responsive DMSNs@AO hold considerable potential in overcoming obstacles for advanced RDT in the treatment of R-CC.


Asunto(s)
Nanopartículas , Dióxido de Silicio , Humanos , Animales , Rayos X , Nanopartículas/química , Femenino , Dióxido de Silicio/química , Ratones , Neoplasias del Cuello Uterino/terapia , Neoplasias del Cuello Uterino/tratamiento farmacológico , Neoplasias del Cuello Uterino/patología , Especies Reactivas de Oxígeno/metabolismo , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/uso terapéutico , Tolerancia a Radiación/efectos de los fármacos , Microambiente Tumoral/efectos de los fármacos , Ratones Desnudos , Células HeLa , Ratones Endogámicos BALB C , Apoptosis/efectos de los fármacos , Línea Celular Tumoral
4.
Plant Methods ; 20(1): 150, 2024 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-39342217

RESUMEN

BACKGROUND: Root phenotyping is particularly challenging because of complexity and inaccessibility of root apparatus. Orientation is one of the most important architectural traits of roots and its characterization is generally addressed using multiple approaches often based on overall measurements which are difficult to correlate to plant specific physiological aspects and its genetic features. Hence, a 3D image analysis approach, based on the recent method of Straumit, is proposed in this study to obtain a local mapping of root angles. RESULTS: Proposed method was applied here on radicles of carrot seedlings grown in real weightlessness on the International Space Station (ISS) and on Earth simulated weightlessness by clinorotation. A reference experiment in 1 g static condition on Earth was also performed. Radicles were imaged by X-ray micro-CT and two novel root orientation traits were defined: the "root angle to sowing plane" (RASP) providing accurate angle distributions for each analysed radicle and the "root orientation changes" (ROC) number. The parameters of the RASP distributions and the ROC values did not exhibit any significant difference in orientation between radicles grown under clinorotation and on the ISS. Only a slight thickening in root corners was found in simulated vs real weightlessness. Such results showed that a simple uniaxial clinostat can be an affordable analog in experimental studies reckoning on weightless radicles growth. CONCLUSIONS: The proposed local orientation mapping approach can be extended also to different root systems providing a contribution in the challenging task of phenotyping complex and important plant structures such as roots.

5.
BMC Oral Health ; 24(1): 1150, 2024 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-39342239

RESUMEN

BACKGROUND: To investigate the anatomic features of the root furcation of permanent mandibular first molars. METHODS: A total of 50 extracted mandibular first molars (25 two-rooted and 25 three-rooted) were collected and scanned using micro-computed tomography. The digital models of teeth and root canal systems were reconstructed three-dimensionally. The tooth models were displayed in parallel projection mode from buccal and distal views. Screenshots were captured and subsequently analyzed using Image-Pro Plus 6.0 software after calibration. The furcation angle, root trunk length, maximum depth and level of distal root concaves of mesial roots, and length of enamel projections were measured, and the furcation types (classified into type V, type U and type W) were detected. Statistical analysis was performed using the Shapiro-Wilk's test, one-way analysis of variance, Student's t-test and Chi-square test. RESULTS: The mean furcation angle between the distobuccal (DB) and distolingual (DL) roots (in distal view) was the greatest (59.2°), whereas the furcation angle between the mesial and DL roots (in buccal view) was the smallest (25.4°) among the four furcation angles (all p < 0.05). Regarding the furcation types, bucco-lingual root trunk length, maximum depth and site of the distal root concavities, and enamel projection length, no significant differences were detected between the three- and two-rooted molar groups (all p > 0.05). The frequency of type V was the highest (54.0%), followed by type U (26.0%), and type W had the lowest occurrence rate (20.0%). The mean length of distal root trunk in the three-rooted mandibular molars was significantly greater than that of the buccal/lingual one (3.7 mm vs. 3.0 mm, p < 0.01). The maximum depth of the distal concavities of the mesial roots was on average 0.66 ± 0.19 mm, and the site was located at an average of 2.8 ± 1.3 mm below furcation. The mean length of buccal enamel projections was significantly longer than that of lingual ones (3.1 mm vs. 0.7 mm, p < 0.01). CONCLUSIONS: The furcation anatomy of the mandibular first molar is complex, and the presence of the DL root may further complicate its topography. A thorough understanding of these anatomic features is essential for successful periodontal treatment.


Asunto(s)
Mandíbula , Diente Molar , Raíz del Diente , Microtomografía por Rayos X , Diente Molar/diagnóstico por imagen , Diente Molar/anatomía & histología , Microtomografía por Rayos X/métodos , Humanos , Raíz del Diente/diagnóstico por imagen , Raíz del Diente/anatomía & histología , Mandíbula/diagnóstico por imagen , Mandíbula/anatomía & histología , Imagenología Tridimensional/métodos
6.
J Forensic Sci ; 2024 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-39294554

RESUMEN

Age estimation plays a crucial role in various fields, including forensic science and anthropology. This study aims to develop and validate DentAge, a deep-learning model for automated age prediction using panoramic dental X-ray images. DentAge was trained on a dataset comprising 21,007 panoramic dental X-ray images sourced from a private dental center in Slovenia. The dataset included subjects aged 4 to 97 years with various dental conditions. Transfer learning was employed, initializing the model with ImageNet weights and fine-tuning on the dental image dataset. The model was trained using stochastic gradient descent with momentum, and mean absolute error (MAE) served as the objective function. Across the test dataset, DentAge achieved an MAE of 3.12 years, demonstrating its efficacy in age prediction. Notably, the model performed well across different age groups, with MAEs ranging from 1.94 (age group [10-20]) to 13.40 years (age group [90-100]). Visual evaluation revealed factors contributing to prediction errors, including prosthetic restorations, tooth loss, and bone resorption. DentAge represents a significant advancement in automated age prediction within dentistry. The model's robust performance across diverse age groups and dental conditions underscores its potential utility in real-world scenarios. Our model will be accessible to the public for further adjustments and validation, ensuring DentAge's effectiveness and trustworthiness in practical scenarios.

7.
Artículo en Inglés | MEDLINE | ID: mdl-39295274

RESUMEN

Metal halide perovskites have emerged as promising materials for X-ray detection due to their high X-ray attenuation coefficients, defect tolerance, and suitability for large-area, low-temperature fabrication. However, the intrinsic high ion conductivity of these materials presents challenges, such as high dark current density and current drift, which impair the stability and sensitivity of perovskite X-ray detectors. This study introduces an approach to mitigating these issues by incorporating 2,2,3,3,3-pentafluoropropylamine hydrochloride (PFH) into polycrystalline MAPbI3-xClx films using a one-step blade-coating method. PFH aggregates at grain boundaries, raising local vacuum energy levels and passivating surface defects, thereby reducing ion conductivity without affecting electron conductivity. As a result, this approach significantly reduces the dark current and enhances sensitivity, achieving a low detection limit of 14.7 nGyair/s. Additionally, it improves signal stability, consistency, and response speed of the detector. These findings suggest that PFH is a promising additive for advancing the performance and practical application of polycrystalline metal halide perovskite-based X-ray detectors.

8.
IUCrJ ; 2024 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-39297240

RESUMEN

MltG, a membrane-bound lytic transglycosylase, has roles in terminating glycan polymerization in peptidoglycan and incorporating glycan chains into the cell wall, making it significant in bacterial cell-wall biosynthesis and remodeling. This study provides the first reported MltG structure from Mycobacterium abscessus (maMltG), a superbug that has high antibiotic resistance. Our structural and biochemical analyses revealed that MltG has a flexible peptidoglycan-binding domain and exists as a monomer in solution. Further, the putative active site of maMltG was disclosed using structural analysis and sequence comparison. Overall, this study contributes to our understanding of the transglycosylation reaction of the MltG family, aiding the design of next-generation antibiotics targeting M. abscessus.

9.
bioRxiv ; 2024 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-39282375

RESUMEN

Dual-specificity mitogen-activated protein kinase (MAPK) phosphatases (MKPs) directly dephosphorylate and inactivate the MAPKs. Although the catalytic mechanism of dephosphorylation of the MAPKs by the MKPs is established, a complete molecular picture of the regulatory interplay between the MAPKs and MKPs still remains to be fully explored. Here, we sought to define the molecular mechanism of MKP5 regulation through an allosteric site within its catalytic domain. We demonstrate using crystallographic and NMR spectroscopy approaches that residue Y435 is required to maintain the structural integrity of the allosteric pocket. Along with molecular dynamics simulations, these data provide insight into how changes in the allosteric pocket propagate conformational flexibility in the surrounding loops to reorganize catalytically crucial residues in the active site. Furthermore, Y435 contributes to the interaction with p38 MAPK and JNK, thereby promoting dephosphorylation. Collectively, these results highlight the role of Y435 in the allosteric site as a novel mode of MKP5 regulation by p38 MAPK and JNK.

10.
Sci Rep ; 14(1): 21646, 2024 09 17.
Artículo en Inglés | MEDLINE | ID: mdl-39284856

RESUMEN

Two cystic fibrosis (CF) rat models, one carrying the common Phe508del mutation and the other a nonsense cystic fibrosis transmembrane conductance regulator (CFTR) mutation (knockout) were previously characterised. Although relevant CFTR mRNA reductions were present in the lung, no overt CF lung disease was observed. This study used flexiVent lung mechanic assessment and regional ventilation assessment via X-ray velocimetry (XV) functional imaging to assess the lung phenotype in both models. To determine the sensitivity of XV regional ventilation imaging, the effect of a localised physical obstruction (delivery of agar beads to part of the lungs) on lung ventilation was examined. At baseline, Phe508del and knockout CF rats had a lower inspiratory capacity, total respiratory system compliance, and static compliance than wildtype rats. Following agar bead delivery all XV ventilation parameters were altered, with substantial increases in poorly ventilated regions and ventilation heterogeneity. XV ventilation maps accurately identified locations of bead-induced airflow changes. Despite unremarkable lung histopathology, this study indicated that CF rats display altered respiratory mechanics, with CF rats needing to exert additional effort to expand and deflate their lungs due to increased stiffness. This study demonstrated the utility of XV imaging providing spatial lung ventilation information.


Asunto(s)
Regulador de Conductancia de Transmembrana de Fibrosis Quística , Fibrosis Quística , Modelos Animales de Enfermedad , Pulmón , Mecánica Respiratoria , Animales , Fibrosis Quística/diagnóstico por imagen , Fibrosis Quística/genética , Fibrosis Quística/fisiopatología , Ratas , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Pulmón/diagnóstico por imagen , Pulmón/metabolismo , Pulmón/patología , Pulmón/fisiopatología , Reología , Masculino , Ratas Sprague-Dawley
11.
Sci Rep ; 14(1): 21629, 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39285202

RESUMEN

Arsenic contamination in aqueous media is a serious environmental problem, especially in developing countries. In this research, the Box-Behnken response surface methodology was used to optimize the most relevant variables affecting arsenic adsorption on the ZnO-halloysite surface, including temperature, adsorbent dosage, pH, contact time, and As (III) initial concentration. The regression analysis indicated that the experimental data were appropriately fitted to a quadratic model with the adjusted R-squared value (R2) of 0.982 for As(III) adsorption capacity and a linear model with R2 of 0.931 for As(III) removal. The p-values for both adsorption capacity and removal efficiency were below 0.05, with F-values of 116.91 and 115.58, respectively, supporting the model's validity. The optimum conditions for maximum removal of As(III) were determined through numerical and graphical optimization using the desirability function. It was found that the optimum conditions for adsorption were pH = 7.99, contact time of 3.99 h, As(III) initial concentration of 49.96 mg/L, and adsorbent dosage of 0.135 g/40 ml. The accuracy of the optimization procedure was confirmed by a confirmatory experiment, which showed a maximum arsenic removal of 91.31% and an adsorption capacity of 12.63 mg/g under optimized conditions. Moreover, XPS analysis was performed at different pH levels to investigate the As (III) adsorption mechanism. The results demonstrated that As(III) adsorption occurs at acidic and neutral pH levels. On the other hand, when pH is increased to 8, As (III) oxidizes to As (V), and then adsorption occurs.

12.
J Radiol Prot ; 44(3)2024 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-39265583

RESUMEN

A dosimeter should ideally be calibrated in a reference field with similar energy and doserate to that which the dosimeter is being used to measure. Environments around nuclear reactors and radiation therapy facilities have high-energy photons with energies exceeding that of60Co gamma rays, and controlling exposure to these photons is important. The Japan Atomic Energy Agency and National Metrology Institute of Japan have high-energy reference fields with energies above several megaelectronvolts for different types of accelerators. Their reference fields have different fluence-energy distributions. In this study, the energy dependencies of the two-cavity ionization chambers, which are often used by secondary standard laboratories, were experimentally and computationally evaluated for each high-energy field. These results agreed well within the relative expanded uncertainties (k= 2), and their capabilities for air kerma measurements in each high-energy reference field were confirmed. Therefore, the capabilities of the air-kerma measurements were verified in the two high-energy reference fields.


Asunto(s)
Fotones , Protección Radiológica , Protección Radiológica/normas , Japón , Radiometría , Dosis de Radiación , Calibración , Dosímetros de Radiación , Diseño de Equipo , Monitoreo de Radiación/métodos , Monitoreo de Radiación/instrumentación
13.
Int J Biol Macromol ; 280(Pt 1): 135652, 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39278443

RESUMEN

Gelatin (Gel) based water-insoluble films with antimicrobial properties were developed by the green method using trans-cinnamaldehyde (TCA) and low-energy X-ray irradiation as dual crosslinkers. The Gel/TCA composite films (GTCF) were prepared at different pH (4, 6, 8, and 10) and crosslinked by incorporating 5 % (w/w, based on Gel) TCA and X-ray irradiation (350 kV and 11.4 mA) with doses of 0, 5, 10 and 15 kGy. The presence of TCA in GTCF forms dense, flexible, and strong films when exposed to X-ray irradiation. The GTCF at pH 6, incorporated with 5 wt% TCA and irradiated with 10 kGy X-ray, displayed the highest degree of crosslinking (DOC) (93.4 ± 3.4 %), tensile strength, excellent UV-barrier (> 99.9 %), antimicrobial (inhibitory capacity of >50 %), and water vapor permeability (4.1 ± 0.6 g.mm/m2.day. kPa), and low solubility in water (0.5 ± 0.3 %), and oxygen permeability. The GTCF, crosslinked with X-ray irradiation, has multifunctional properties and strong potential in the sustainable packaging industry to augment the shelf life of food and reduce food waste. To the best of our information, this is the first and novel report investigating the effects of pH on the properties of GTCF crosslinked with X-ray.

14.
Eur Radiol Exp ; 8(1): 106, 2024 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-39298011

RESUMEN

BACKGROUND: Patellar instability is a well-known pathology in which kinematics can be investigated using metrics such as tibial tuberosity tracheal groove (TTTG), the bisect offset (BO), and the lateral patellar tilt (LPT). We used dynamic computed tomography (CT) to investigate the patellar motion of healthy subjects in weight-bearing conditions to provide normative values for TTTG, BO, and LPT, as well as to define whether BO and LPT are affected by the morphology of the trochlear groove. METHODS: Dynamic scanning was used to acquire images during weight-bearing in 21 adult healthy volunteers. TTTG, BO, and LPT metrics were computed between 0° and 30° of knee flexion. Sulcus angle, sulcus depth, and lateral trochlear inclination were calculated and used with the TTTG for simple linear regression models. RESULTS: All metrics gradually decreased during eccentric movement (TTTG, -6.9 mm; BO, -12.6%; LPT, -4.3°). No significant differences were observed between eccentric and concentric phases at any flexion angle for all metrics. Linear regression between kinematic metrics towards full extension showed a moderate fit between BO and TTTG (R2 0.60, ß 1.75) and BO and LPT (R2 0.59, ß 1.49), and a low fit between TTTG and LPT (R2 0.38, ß 0.53). A high impact of the TTTG distance over BO was shown in male participants (R2 0.71, ß 1.89) and patella alta individuals (R2 0.55, ß 1.91). CONCLUSION: We provided preliminary normative values of three common metrics during weight-bearing dynamic CT and showed the substantial impact of lateralisation of the patella tendon over patella displacement. RELEVANCE STATEMENT: These normative values can be used by clinicians when evaluating knee patients using TTTG, BO, and LPT metrics. The lateralisation of the patellar tendon in subjects with patella alta or in males significantly impacts the lateral displacement of the patella. KEY POINTS: Trochlear groove morphology had no substantial impact on motion prediction. The lateralisation of the patellar tendon seems a strong predictor of lateral displacement of the patella in male participants. Participants with patella alta displayed a strong fit between the patellar lateral displacement and tilt. TTTG, BO, and LPT decreased during concentric movement. Concentric and eccentric phases did not show differences for all metrics.


Asunto(s)
Voluntarios Sanos , Rótula , Tomografía Computarizada por Rayos X , Soporte de Peso , Humanos , Masculino , Femenino , Tomografía Computarizada por Rayos X/métodos , Adulto , Rótula/diagnóstico por imagen , Rótula/anatomía & histología , Valores de Referencia , Fenómenos Biomecánicos , Adulto Joven , Rango del Movimiento Articular/fisiología , Movimiento/fisiología
15.
Eur Radiol Exp ; 8(1): 105, 2024 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-39298080

RESUMEN

BACKGROUND: Regular disease monitoring with low-dose high-resolution (LD-HR) computed tomography (CT) scans is necessary for the clinical management of people with cystic fibrosis (pwCF). The aim of this study was to compare the image quality and radiation dose of LD-HR protocols between photon-counting CT (PCCT) and energy-integrating detector system CT (EID-CT) in pwCF. METHODS: This retrospective study included 23 pwCF undergoing LD-HR chest CT with PCCT who had previously undergone LD-HR chest CT with EID-CT. An intraindividual comparison of radiation dose and image quality was conducted. The study measured the dose-length product, volumetric CT dose index, effective dose and signal-to-noise ratio (SNR). Three blinded radiologists assessed the overall image quality, image sharpness, and image noise using a 5-point Likert scale ranging from 1 (deficient) to 5 (very good) for image quality and image sharpness and from 1 (very high) to 5 (very low) for image noise. RESULTS: PCCT used approximately 42% less radiation dose than EID-CT (median effective dose 0.54 versus 0.93 mSv, p < 0.001). PCCT was consistently rated higher than EID-CT for overall image quality and image sharpness. Additionally, image noise was lower with PCCT compared to EID-CT. The average SNR of the lung parenchyma was lower with PCCT compared to EID-CT (p < 0.001). CONCLUSION: In pwCF, LD-HR chest CT protocols using PCCT scans provided significantly better image quality and reduced radiation exposure compared to EID-CT. RELEVANCE STATEMENT: In pwCF, regular follow-up could be performed through photon-counting CT instead of EID-CT, with substantial advantages in terms of both lower radiation exposure and increased image quality. KEY POINTS: Photon-counting CT (PCCT) and energy-integrating detector system CT (EID-CT) were compared in 23 people with cystic fibrosis (pwCF). Image quality was rated higher for PCCT than for EID-CT. PCCT used approximately 42% less radiation dose and offered superior image quality than EID-CT.


Asunto(s)
Fibrosis Quística , Fotones , Dosis de Radiación , Radiografía Torácica , Tomografía Computarizada por Rayos X , Fibrosis Quística/diagnóstico por imagen , Humanos , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/métodos , Masculino , Femenino , Adulto , Radiografía Torácica/métodos , Relación Señal-Ruido , Adulto Joven
16.
Arch Biochem Biophys ; 761: 110156, 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39299479

RESUMEN

Human triosephosphate isomerase G122R, also known as TPI-Manchester, is a thermolabile variant detected in a screening of more than 3400 individuals from a population in Ann Arbor, Michigan. Here, the crystallographic structure of G122R was solved to determine the molecular basis of its thermal stability. Structural analysis revealed an increase in the flexibility of residues at the dimer interface, even though R122 is about 20 Å away, suggesting that long-range electrostatic interactions may play a key role in the mutation effect.

17.
BMC Med Imaging ; 24(1): 251, 2024 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-39300334

RESUMEN

The analysis of the psoas muscle in morphological and functional imaging has proved to be an accurate approach to assess sarcopenia, i.e. a systemic loss of skeletal muscle mass and function that may be correlated to multifactorial etiological aspects. The inclusion of sarcopenia assessment into a radiological workflow would need the implementation of computational pipelines for image processing that guarantee segmentation reliability and a significant degree of automation. The present study utilizes three-dimensional numerical schemes for psoas segmentation in low-dose X-ray computed tomography images. Specifically, here we focused on the level set methodology and compared the performances of two standard approaches, a classical evolution model and a three-dimension geodesic model, with the performances of an original first-order modification of this latter one. The results of this analysis show that these gradient-based schemes guarantee reliability with respect to manual segmentation and that the first-order scheme requires a computational burden that is significantly smaller than the one needed by the second-order approach.


Asunto(s)
Imagenología Tridimensional , Músculos Psoas , Sarcopenia , Tomografía Computarizada por Rayos X , Humanos , Músculos Psoas/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Imagenología Tridimensional/métodos , Sarcopenia/diagnóstico por imagen , Reproducibilidad de los Resultados , Algoritmos , Masculino , Femenino , Anciano , Persona de Mediana Edad , Interpretación de Imagen Radiográfica Asistida por Computador/métodos
18.
Eur Heart J Digit Health ; 5(5): 524-534, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39318689

RESUMEN

Aims: Aortic elongation can result from age-related changes, congenital factors, aneurysms, or conditions affecting blood vessel elasticity. It is associated with cardiovascular diseases and severe complications like aortic aneurysms and dissection. We assess qualitatively and quantitatively explainable methods to understand the decisions of a deep learning model for detecting aortic elongation using chest X-ray (CXR) images. Methods and results: In this study, we evaluated the performance of deep learning models (DenseNet and EfficientNet) for detecting aortic elongation using transfer learning and fine-tuning techniques with CXR images as input. EfficientNet achieved higher accuracy (86.7% ± 2.1), precision (82.7% ± 2.7), specificity (89.4% ± 1.7), F1 score (82.5% ± 2.9), and area under the receiver operating characteristic (92.7% ± 0.6) but lower sensitivity (82.3% ± 3.2) compared with DenseNet. To gain insights into the decision-making process of these models, we employed gradient-weighted class activation mapping and local interpretable model-agnostic explanations explainability methods, which enabled us to identify the expected location of aortic elongation in CXR images. Additionally, we used the pixel-flipping method to quantitatively assess the model interpretations, providing valuable insights into model behaviour. Conclusion: Our study presents a comprehensive strategy for analysing CXR images by integrating aortic elongation detection models with explainable artificial intelligence techniques. By enhancing the interpretability and understanding of the models' decisions, this approach holds promise for aiding clinicians in timely and accurate diagnosis, potentially improving patient outcomes in clinical practice.

19.
Artículo en Inglés | MEDLINE | ID: mdl-39320305

RESUMEN

The discovery of novel quaternary intermetallic compounds R2MoSi2C (R = Y, Gd) in the R-Mo-Si-C system is reported. Their crystal structure was investigated using single-crystal X-ray diffraction. It is shown that the Y2MoSi2C and Gd2MoSi2C compounds crystallize in the tetragonal space group P4/mbm (Pearson symbol tP12) with unit-cell parameters a = 6.9525 (18) Å, c = 4.1962 (16) Å, and a = 6.9945 (16) Å, c = 4.2020 (14) Å, respectively.

20.
Artículo en Inglés | MEDLINE | ID: mdl-39320308

RESUMEN

Thiophosgene is one of the principal C=S building blocks in synthetic chemistry. At room temperature, thiophosgene is a red liquid. While its properties in the liquid and gaseous states are well known, a comprehensive characterization of thiophosgene in its solid state is presented here. Differential scanning calorimetry shows that thiophosgene forms a supercooled melt before rapidly crystallizing. Its melting point is 231.85 K (-41.3 °C). At 80 K, thiophosgene crystallizes in space group P63/m [No. 174, a = b = 5.9645 (2), c = 6.2835 (3) Å, V = 193.59 (2) Å3]. The molecule shows a distinct rotational disorder: all S and Cl positions are of mixed occupancy and the disorder does not resolve at temperatures as low as 10 K, as was shown by neutron powder diffraction. Infrared, Raman and inelastic neutron scattering spectra were collected and assigned with the aid of quantum chemical calculations. A larger ordered structural model allowed for better agreement between the measured and calculated spectra, further indicating that disorder is an inherent feature of solid-state thiophosgene.

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