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1.
Nat Immunol ; 25(2): 330-342, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38172260

RESUMEN

Antibody-secreting plasma cells (PCs) are generated in secondary lymphoid organs but are reported to reside in an emerging range of anatomical sites. Analysis of the transcriptome of different tissue-resident (Tr)PC populations revealed that they each have their own transcriptional signature indicative of functional adaptation to the host tissue environment. In contrast to expectation, all TrPCs were extremely long-lived, regardless of their organ of residence, with longevity influenced by intrinsic factors like the immunoglobulin isotype. Analysis at single-cell resolution revealed that the bone marrow is unique in housing a compendium of PCs generated all over the body that retain aspects of the transcriptional program indicative of their tissue of origin. This study reveals that extreme longevity is an intrinsic property of TrPCs whose transcriptome is imprinted by signals received both at the site of induction and within the tissue of residence.


Asunto(s)
Médula Ósea , Células Plasmáticas , Células de la Médula Ósea
2.
Nature ; 629(8012): 555-560, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38658758

RESUMEN

The tokamak approach, utilizing a toroidal magnetic field configuration to confine a hot plasma, is one of the most promising designs for developing reactors that can exploit nuclear fusion to generate electrical energy1,2. To reach the goal of an economical reactor, most tokamak reactor designs3-10 simultaneously require reaching a plasma line-averaged density above an empirical limit-the so-called Greenwald density11-and attaining an energy confinement quality better than the standard high-confinement mode12,13. However, such an operating regime has never been verified in experiments. In addition, a long-standing challenge in the high-confinement mode has been the compatibility between a high-performance core and avoiding large, transient edge perturbations that can cause very high heat loads on the plasma-facing-components in tokamaks. Here we report the demonstration of stable tokamak plasmas with a line-averaged density approximately 20% above the Greenwald density and an energy confinement quality of approximately 50% better than the standard high-confinement mode, which was realized by taking advantage of the enhanced suppression of turbulent transport granted by high density-gradients in the high-poloidal-beta scenario14,15. Furthermore, our experimental results show an integration of very low edge transient perturbations with the high normalized density and confinement core. The operating regime we report supports some critical requirements in many fusion reactor designs all over the world and opens a potential avenue to an operating point for producing economically attractive fusion energy.

3.
Nature ; 607(7919): 468-473, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35859194

RESUMEN

Quantum many-body systems away from equilibrium host a rich variety of exotic phenomena that are forbidden by equilibrium thermodynamics. A prominent example is that of discrete time crystals1-8, in which time-translational symmetry is spontaneously broken in periodically driven systems. Pioneering experiments have observed signatures of time crystalline phases with trapped ions9,10, solid-state spin systems11-15, ultracold atoms16,17 and superconducting qubits18-20. Here we report the observation of a distinct type of non-equilibrium state of matter, Floquet symmetry-protected topological phases, which are implemented through digital quantum simulation with an array of programmable superconducting qubits. We observe robust long-lived temporal correlations and subharmonic temporal response for the edge spins over up to 40 driving cycles using a circuit of depth exceeding 240 and acting on 26 qubits. We demonstrate that the subharmonic response is independent of the initial state, and experimentally map out a phase boundary between the Floquet symmetry-protected topological and thermal phases. Our results establish a versatile digital simulation approach to exploring exotic non-equilibrium phases of matter with current noisy intermediate-scale quantum processors21.

4.
Nature ; 600(7888): 253-258, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34880429

RESUMEN

The global terrestrial carbon sink is increasing1-3, offsetting roughly a third of anthropogenic CO2 released into the atmosphere each decade1, and thus serving to slow4 the growth of atmospheric CO2. It has been suggested that a CO2-induced long-term increase in global photosynthesis, a process known as CO2 fertilization, is responsible for a large proportion of the current terrestrial carbon sink4-7. The estimated magnitude of the historic increase in photosynthesis as result of increasing atmospheric CO2 concentrations, however, differs by an order of magnitude between long-term proxies and terrestrial biosphere models7-13. Here we quantify the historic effect of CO2 on global photosynthesis by identifying an emergent constraint14-16 that combines terrestrial biosphere models with global carbon budget estimates. Our analysis suggests that CO2 fertilization increased global annual photosynthesis by 11.85 ± 1.4%, or 13.98 ± 1.63 petagrams carbon (mean ± 95% confidence interval) between 1981 and 2020. Our results help resolve conflicting estimates of the historic sensitivity of global photosynthesis to CO2, and highlight the large impact anthropogenic emissions have had on ecosystems worldwide.


Asunto(s)
Atmósfera/química , Dióxido de Carbono/metabolismo , Mapeo Geográfico , Internacionalidad , Fotosíntesis , Secuestro de Carbono , Respiración de la Célula , Ecosistema , Actividades Humanas , Aprendizaje Automático , Plantas/metabolismo , Tecnología de Sensores Remotos , Imágenes Satelitales , Análisis Espacio-Temporal
5.
Nature ; 590(7845): 238-242, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33568823

RESUMEN

The manipulation of quantum states of light1 holds the potential to enhance searches for fundamental physics. Only recently has the maturation of quantum squeezing technology coincided with the emergence of fundamental physics searches that are limited by quantum uncertainty2,3. In particular, the quantum chromodynamics axion provides a possible solution to two of the greatest outstanding problems in fundamental physics: the strong-CP (charge-parity) problem of quantum chromodynamics4 and the unknown nature of dark matter5-7. In dark matter axion searches, quantum uncertainty manifests as a fundamental noise source, limiting the measurement of the quadrature observables used for detection. Few dark matter searches have approached this limit3,8, and until now none has exceeded it. Here we use vacuum squeezing to circumvent the quantum limit in a search for dark matter. By preparing a microwave-frequency electromagnetic field in a squeezed state and near-noiselessly reading out only the squeezed quadrature9, we double the search rate for axions over a mass range favoured by some recent theoretical projections10,11. We find no evidence of dark matter within the axion rest energy windows of 16.96-17.12 and 17.14-17.28 microelectronvolts. Breaking through the quantum limit invites an era of fundamental physics searches in which noise reduction techniques yield unbounded benefit compared with the diminishing returns of approaching the quantum limit.

6.
Nature ; 566(7742): 131-135, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30675061

RESUMEN

Cells use compartmentalization of enzymes as a strategy to regulate metabolic pathways and increase their efficiency1. The α- and ß-carboxysomes of cyanobacteria contain ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco)-a complex of eight large (RbcL) and eight small (RbcS) subunits-and carbonic anhydrase2-4. As HCO3- can diffuse through the proteinaceous carboxysome shell but CO2 cannot5, carbonic anhydrase generates high concentrations of CO2 for carbon fixation by Rubisco6. The shell also prevents access to reducing agents, generating an oxidizing environment7-9. The formation of ß-carboxysomes involves the aggregation of Rubisco by the protein CcmM10, which exists in two forms: full-length CcmM (M58 in Synechococcus elongatus PCC7942), which contains a carbonic anhydrase-like domain8 followed by three Rubisco small subunit-like (SSUL) modules connected by flexible linkers; and M35, which lacks the carbonic anhydrase-like domain11. It has long been speculated that the SSUL modules interact with Rubisco by replacing RbcS2-4. Here we have reconstituted the Rubisco-CcmM complex and solved its structure. Contrary to expectation, the SSUL modules do not replace RbcS, but bind close to the equatorial region of Rubisco between RbcL dimers, linking Rubisco molecules and inducing phase separation into a liquid-like matrix. Disulfide bond formation in SSUL increases the network flexibility and is required for carboxysome function in vivo. Notably, the formation of the liquid-like condensate of Rubisco is mediated by dynamic interactions with the SSUL domains, rather than by low-complexity sequences, which typically mediate liquid-liquid phase separation in eukaryotes12,13. Indeed, within the pyrenoids of eukaryotic algae, the functional homologues of carboxysomes, Rubisco adopts a liquid-like state by interacting with the intrinsically disordered protein EPYC114. Understanding carboxysome biogenesis will be important for efforts to engineer CO2-concentrating mechanisms in plants15-19.


Asunto(s)
Proteínas Bacterianas/metabolismo , Orgánulos/metabolismo , Multimerización de Proteína , Ribulosa-Bifosfato Carboxilasa/química , Ribulosa-Bifosfato Carboxilasa/metabolismo , Synechococcus/enzimología , Proteínas Bacterianas/química , Proteínas Bacterianas/ultraestructura , Ciclo del Carbono , Dióxido de Carbono/metabolismo , Anhidrasas Carbónicas/química , Anhidrasas Carbónicas/metabolismo , Anhidrasas Carbónicas/ultraestructura , Microscopía por Crioelectrón , Disulfuros/metabolismo , Modelos Moleculares , Oxidación-Reducción , Subunidades de Proteína/química , Subunidades de Proteína/metabolismo , Ribulosa-Bifosfato Carboxilasa/ultraestructura
8.
Nature ; 569(7754): 53-58, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-31043730

RESUMEN

Nuclear magic numbers correspond to fully occupied energy shells of protons or neutrons inside atomic nuclei. Doubly magic nuclei, with magic numbers for both protons and neutrons, are spherical and extremely rare across the nuclear landscape. Although the sequence of magic numbers is well established for stable nuclei, experimental evidence has revealed modifications for nuclei with a large asymmetry between proton and neutron numbers. Here we provide a spectroscopic study of the doubly magic nucleus 78Ni, which contains fourteen neutrons more than the heaviest stable nickel isotope. We provide direct evidence of its doubly magic nature, which is also predicted by ab initio calculations based on chiral effective-field theory interactions and the quasi-particle random-phase approximation. Our results also indicate the breakdown of the neutron magic number 50 and proton magic number 28 beyond this stronghold, caused by a competing deformed structure. State-of-the-art phenomenological shell-model calculations reproduce this shape coexistence, predicting a rapid transition from spherical to deformed ground states, with 78Ni as the turning point.

9.
Ann Surg Oncol ; 31(1): 433-451, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37777688

RESUMEN

INTRODUCTION: The tumor microenvironment (TME) plays a crucial role in therapy response and modulation of immunologic surveillance. Adjuvant immunotherapy has recently been introduced in post-surgery treatment of locally advanced esophageal cancer (EC) with residual pathological disease after neoadjuvant chemoradiotherapy (nCRT). F-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) remains a valuable imaging tool to assess therapy response and to visualize metabolic TME; however, there is still a paucity in understanding the interaction between the TME and nCRT response. This systematic review investigated the potential of TME biomarkers and 18F-FDG-PET/CT features to predict pathological and clinical response (CR) after nCRT in EC. METHODS: A literature search of the Medline and Embase electronic databases identified 4190 studies. Studies regarding immune and metabolic TME biomarkers and 18F-FDG-PET/CT features were included for predicting pathological response (PR) and/or CR after nCRT. Separate analyses were performed for 18F-FDG-PET/CT markers and these TME biomarkers. RESULTS: The final analysis included 21 studies-10 about immune and metabolic markers alone and 11 with additional 18F-FDG-PET/CT features. High CD8 infiltration before and after nCRT, and CD3 and CD4 infiltration after nCRT, generally correlated with better PR. A high expression of tumoral or stromal programmed death-ligand 1 (PD-L1) after nCRT was generally associated with poor PR. Moreover, total lesion glycolysis (TLG) and metabolic tumor volume (MTV) of the primary tumor were potentially predictive for clinical and PR. CONCLUSION: CD8, CD4, CD3, and PD-L1 are promising immune markers in predicting PR, whereas TLG and MTV are potential 18F-FDG-PET/CT features to predict clinical and PR after nCRT in EC.


Asunto(s)
Neoplasias Esofágicas , Tomografía Computarizada por Tomografía de Emisión de Positrones , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Fluorodesoxiglucosa F18 , Terapia Neoadyuvante/métodos , Antígeno B7-H1 , Microambiente Tumoral , Quimioradioterapia/métodos , Neoplasias Esofágicas/diagnóstico por imagen , Neoplasias Esofágicas/terapia , Neoplasias Esofágicas/patología , Biomarcadores de Tumor , Radiofármacos , Carga Tumoral , Estudios Retrospectivos
10.
Phys Rev Lett ; 132(23): 235102, 2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38905687

RESUMEN

Multimachine empirical scaling predicts an extremely narrow heat exhaust layer in future high magnetic field tokamaks, producing high power densities that require mitigation. In the experiments presented, the width of this exhaust layer is nearly doubled using actuators to increase turbulent transport in the plasma edge. This is achieved in low collisionality, high confinement edge pedestals with their gradients limited by turbulent transport instead of large-scale, coherent instabilities. The exhaust heat flux profile width and divertor leg diffusive spreading both double as a high frequency band of turbulent fluctuations propagating in the electron diamagnetic direction doubles in amplitude. The results are quantitatively reproduced in electromagnetic XGC particle-in-cell simulations which show the heat flux carried by electrons emerges to broaden the heat flux profile, directly supported by Langmuir probe measurements.

11.
Calcif Tissue Int ; 114(4): 386-396, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38355832

RESUMEN

The previous observational studies could not overcome the effects of confounding variables and reverse causality. We aimed to determine whether there is a causal relationship between systemic lupus erythematosus and osteoporosis in East Asian and European populations, respectively, by two-sample Mendelian Randomization analysis. We obtained and downloaded data from publicly available genome-wide association study databases and analyses for East Asian and European populations, including systemic lupus erythematosus (SLE), osteoporosis (OP), multisite bone mineral density (BMD), and OP with fracture. After screening for instrumental single-nucleotide polymorphisms (SNPs) significantly correlated to SLE, the inverse-variance weighted (IVW) method was used for calculating the ratio and 95% confidence interval, besides utilizing MR-Egger, weighted median, and weighted mode to assess the robustness of the primary outcome. Moreover, multiple analyses, including MR-PRESSO, MR-Egger intercept, Cochran's Q test, as well as "leave-one-out" sensitivity, were used for evaluating horizontal pleiotropy, heterogeneity, and stability. Finally, we exchanged exposure and outcome and performed a reverse MR analysis. IVW (OR = 1.05, 95% CI = 1.01-1.09, P = 0.009) indicated a significant positive correlation between genetically predicted SLE and OP in East Asians. Furthermore, neither heterogeneity nor horizontal pleiotropy was observed. In Europe, there was no significant genetically predicted causal relation between SLE and OP. Bi-directional MR analysis showed no reverse causality between SLE and OP. In the East Asian population, genetically predicted SLE may have had a positive causal relationship with OP. In Europe, there is insufficient evidence for a potential causal relation between SLE and OP or BMD and fracture, and the correlations currently observed may be attributed to a variety of confounder variables.


Asunto(s)
Fracturas Óseas , Lupus Eritematoso Sistémico , Osteoporosis , Humanos , Etnicidad , Estudio de Asociación del Genoma Completo , Análisis de la Aleatorización Mendeliana , Osteoporosis/genética , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/genética , Polimorfismo de Nucleótido Simple
12.
Scand J Rheumatol ; 53(1): 59-62, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37650252

RESUMEN

OBJECTIVE: To observe the effect of belimumab treatment in refractory anti-phospholipid antibody-associated immune thrombocytopenia with systemic lupus erythematosus (SLE). METHOD: Four SLE patients with refractory anti-phospholipid antibody-associated immune thrombocytopenia were included in this one-arm observational study. Inclusion criteria were a diagnosis of SLE according to 1997 American College of Rheumatology criteria, severe immune thrombocytopenia (platelets <30 × 109/L), no bleeding symptoms, lack of satisfactory response to traditional treatment, and high-titre anti-phospholipid antibodies. All patients received belimumab (Benlysta®) for 6 months. RESULTS: The mean platelet count was 21.8 × 109 cells/L, ranging between 16 and 29 × 109/L at baseline, 123.3 × 109/L at 1 month, and 172.5 × 109/L at the end of 6 months after belimumab treatment. No bleeding complications occurred during the entire follow-up period. CONCLUSION: In this study, belimumab reduced the anti-phospholipid antibodies while increasing the platelet count in SLE patients with anti-phospholipid antibody-associated immune thrombocytopenia.


Asunto(s)
Lupus Eritematoso Sistémico , Púrpura Trombocitopénica Idiopática , Humanos , Inmunosupresores/uso terapéutico , Resultado del Tratamiento , Índice de Severidad de la Enfermedad , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/tratamiento farmacológico
13.
Periodontol 2000 ; 2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38803016

RESUMEN

Autologous platelet concentrates (APCs) have demonstrated clear benefits across various clinical applications, including alveolar ridge preservation, guided tissue regeneration, guided bone regeneration, sinus floor elevation (both lateral window approach and transcrestal technique), endodontic surgery, the treatment of medication-related osteonecrosis of the jaw bones, and periodontal plastic surgery. To ensure an optimal clinical outcome, clinicians must adhere strictly to the protocol to prepare the APCs and, especially follow evidence-based surgical guidelines, often simple but crucial, to minimize the likelihood of errors. The majority of clinical trials reported on second-generation APCs [the leukocyte- and platelet-rich fibrin (L-PRF) family, including its modifications (A-PRF, A-PRF+, CGF, T-PRF, H-PRF, etc.)]. These second-generation APCs offer additional benefits compared to the first-generation APCs, making them the preferred choice for the development of clinical recommendations. These recommendations have been formulated through a meticulous examination of the available clinical data and the clinical experience of the authors of this paper.

14.
Phys Chem Chem Phys ; 26(20): 14930-14936, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38738788

RESUMEN

The unique 4f orbitals and abundant electronic energy levels of rare earth elements enable effective doping and modification to enhance hydrogen storage performance, making it an increasingly prominent focus of research. The structures of neutral and cationic CeHn0/+ (n = 2-20) clusters have been determined using the Crystal Structure AnaLYsis by Particle Swarm Optimization (CALYPSO) method in conjunction with density functional theory (DFT). Interestingly, the CeH13 and CeH14+ exhibit remarkable stability in the doublet state with Cs and C2v symmetry, respectively. The adsorption energy of CeHn0/+ (n = 2-20) suggests a preference for H atoms to chemically adsorb on Ce atoms. The analysis of molecular orbital composition reveals that the stability of both CeH13 and CeH14+ is attributed to the significant hybridization between the H 1s and Ce 4f orbitals. Both CeH13 and CeH14+ demonstrate significant hydrogen storage capacities, with values reaching 8.5 wt% and 9.1 wt%, respectively.

15.
J Biomed Inform ; 156: 104683, 2024 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-38925281

RESUMEN

OBJECTIVE: Despite increased availability of methodologies to identify algorithmic bias, the operationalization of bias evaluation for healthcare predictive models is still limited. Therefore, this study proposes a process for bias evaluation through an empirical assessment of common hospital readmission models. The process includes selecting bias measures, interpretation, determining disparity impact and potential mitigations. METHODS: This retrospective analysis evaluated racial bias of four common models predicting 30-day unplanned readmission (i.e., LACE Index, HOSPITAL Score, and the CMS readmission measure applied as is and retrained). The models were assessed using 2.4 million adult inpatient discharges in Maryland from 2016 to 2019. Fairness metrics that are model-agnostic, easy to compute, and interpretable were implemented and apprised to select the most appropriate bias measures. The impact of changing model's risk thresholds on these measures was further assessed to guide the selection of optimal thresholds to control and mitigate bias. RESULTS: Four bias measures were selected for the predictive task: zero-one-loss difference, false negative rate (FNR) parity, false positive rate (FPR) parity, and generalized entropy index. Based on these measures, the HOSPITAL score and the retrained CMS measure demonstrated the lowest racial bias. White patients showed a higher FNR while Black patients resulted in a higher FPR and zero-one-loss. As the models' risk threshold changed, trade-offs between models' fairness and overall performance were observed, and the assessment showed all models' default thresholds were reasonable for balancing accuracy and bias. CONCLUSIONS: This study proposes an Applied Framework to Assess Fairness of Predictive Models (AFAFPM) and demonstrates the process using 30-day hospital readmission model as the example. It suggests the feasibility of applying algorithmic bias assessment to determine optimized risk thresholds so that predictive models can be used more equitably and accurately. It is evident that a combination of qualitative and quantitative methods and a multidisciplinary team are necessary to identify, understand and respond to algorithm bias in real-world healthcare settings. Users should also apply multiple bias measures to ensure a more comprehensive, tailored, and balanced view. The results of bias measures, however, must be interpreted with caution and consider the larger operational, clinical, and policy context.

16.
J Clin Periodontol ; 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38566468

RESUMEN

AIM: This study aimed to reveal the unique microenvironment of peri-implantitis through single-cell analysis. MATERIALS AND METHODS: Herein, we performed single-cell RNA sequencing (scRNA-seq) of biopsies from patients with peri-implantitis (PI) and compared the results with healthy individuals (H) and patients with periodontitis (PD). RESULTS: Decreased numbers of stromal cells and increased immune cells were found in the PI group, which implies a severe inflammatory infiltration. The fibroblasts were found to be heterogeneous and the specific pro-inflammatory CXCL13+ sub-cluster was more represented in the PI group, in contrast to the PD and H groups. Furthermore, more neutrophil infiltration was detected in the PI group than in the PD group, and cell-cell communication and ligand-receptor pairs revealed most neutrophils were recruited by CXCL13+ fibroblasts through CXCL8/CXCL6-CXCR2/CXCR1. Notably, our study demonstrated that the unique microenvironment of the PI group promoted the differentiation of monocyte/macrophage lineage cells into osteoclasts, which might explain the faster and more severe bone resorption in the progression of PI than PD. CONCLUSIONS: Collectively, this study suggests a unique immune microenvironment of PI, which may explain the differences between PI and PD in the clinic. These outcomes will aid in finding new specific and effective treatments for PI.

17.
Clin Radiol ; 79(1): 60-66, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37838543

RESUMEN

AIM: To investigate the value of multiparametric magnetic resonance imaging (MRI)-based radiomics nomograms for predicting the hormone receptor (HR) status of HER2-positive breast cancer. MATERIALS AND METHODS: Patients with HER2-positive invasive breast cancer were divided randomly into training (68 patients) and validation (30 patients) sets. All were classified as either HR-positive (HR+) or negative (HR-) at histopathology. Two radiologists outlined the three-dimensional (3D) volumetric regions of interest (VOI) on the MRI images. Features (n=1,096) were extracted from the T2-weighted imaging (WI), apparent diffusion coefficient (ADC), and dynamic contrast-enhanced (DCE) images separately. Dimensionality was reduced using feature screening. Binary radiomics prediction models were established using a logistic regression classifier and were validated in the validation set. To construct a nomogram, independent predictors were identified using multivariate logistic regression analysis. The predictive efficacy of the model was assessed using the area under the receiver operating characteristic curve (AUC). RESULTS: Ten radiomics features were obtained after feature dimensionality reduction based on the merged T2WI, ADC, and DCE images. The diagnostic efficacy of the radiomics signature using the three sequences was better than that of any single sequence (training set AUC: 0.797; validation set AUC: 0.75). Using multivariate logistic regression analysis, the independent predictors for identifying HR status were combined radiomics signature and peritumoural oedema. Nomograms constructed by combining the radiomics signature and peritumoural oedema showed good discrimination in both the training and validation sets (AUC: 0.815 and 0. 805, respectively). CONCLUSION: A multiparametric MRI-based nomogram incorporating the radiomics signature and peritumoural oedema can assess the HR status of HER2-positive breast cancer. The resulting model can improve diagnostic accuracy, improving patient outcomes.


Asunto(s)
Neoplasias de la Mama , Imágenes de Resonancia Magnética Multiparamétrica , Humanos , Femenino , Nomogramas , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/patología , Radiómica , Estudios Retrospectivos , Imagen por Resonancia Magnética/métodos , Edema , Hormonas
18.
Clin Radiol ; 79(4): 296-302, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38307815

RESUMEN

AIM: To evaluate the feasibility and image quality of intravoxel incoherent motion diffusion-weighted imaging (IVIM) using gradient- and spin-echo (GRASE) in solitary pulmonary lesions (SPLs) compared to echo planar imaging (EPI) and turbo spin-echo (TSE) at 3 T. MATERIALS AND METHODS: Forty-two patients with SPLs underwent lung magnetic resonance imaging (MRI) using TSE-IVIM, GRASE-IVIM, and EPI-IVIM at 3 T. Signal ratio (SR), contrast ratio (CR), and image distortion ratio (DR) of three sequences were compared. The reproducibility and repeatability of the apparent diffusion coefficient (ADC) and IVIM-derived parameters were assessed using the interclass correlation coefficient (ICC) and coefficient of variation (CV). The repeatability of the ADC and IVIM-derived parameters between all sequences was evaluated using the Bland-Altman method. RESULTS: EPI-IVIM had a higher SR, lower CR, and higher DR (p<0.05); however, there was no significant difference between TSE-IVIM and GRASE-IVIM (p>0.05). Compared to the D and f values of TSE-IVIM (ICC lower limit >0.90), GRASE-IVIM and EPI-IVIM showed poor reproducibility (ICC lower limit<0.90). The repeatability of the ADC and D values obtained by TSE-IVIM (CV, 1.93-2.96% and 2.44-3.18%, respectively) and GRASE-IVIM (CV, 2.56-3.12% and 3.21-3.51%, respectively) were superior to those of EPI-IVIM (CV, 10.03-10.2% and 11.30-11.57%). The repeatability of D∗ and f values for all sequences was poor. Bland-Altman analysis showed wide limits of agreement between the ADC and IVIM-derived parameters for all sequences. CONCLUSION: GRASE-IVIM reduced the DR, improved the stability of the ADC and D values on repeated scans, and had the shortest scanning time.


Asunto(s)
Neoplasias Pulmonares , Pulmón , Humanos , Reproducibilidad de los Resultados , Pulmón/diagnóstico por imagen , Imagen de Difusión por Resonancia Magnética/métodos , Imagen Eco-Planar/métodos , Movimiento (Física)
19.
Clin Radiol ; 79(6): e834-e841, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38556393

RESUMEN

AIMS: Alcoholic cardiomyopathy (ACM) is recognized as a type of non-ischemic dilated cardiomyopathy (DCM). To date, the clinical prognosis of ACM remains a topic of debate in previous studies and there are limited studies on its cardiac MRI characteristics. The aim of this study was to summarize the clinical and MRI features of ACM patients and to identify the predictors of adverse prognosis based on clinical characteristics and MRI imaging findings. MATERIALS AND METHODS: Adult patients who were clinically diagnosed with ACM and underwent enhanced CMR between September 2015 and August 2022 were retrospectively enrolled. The primary endpoints were major adverse cardiovascular events, including cardiac-related death, heart transplantation, hospitalization for heart failure and life-threatening ventricular arrhythmias (sustained ventricular tachycardia, ventricular fibrillation, or ICD shock). The risk factors associated with these primary end points were identified using multivariable Cox analysis. RESULTS: A total of 62 ACM patients (50 ± 9 years, 62 men) were included. The majority of patients presented with symptoms of heart failure. Over a median follow-up period of 30.3 months (IQR 12.2-57.7 months), 24 patients reached the primary endpoints. For clinical variables, multivariable analysis showed that drinking duration (HR=1.05; 95%CI:1.01, 1.11; p=0.03) and persistent drinking (HR=3.71; 95%CI:1.46, 9.44; p=0.01) were associated with MACE. For CMR variables, late gadolinium enhancement (LGE) percent (HR = 1.09; 95% CI: 1.03, 1.14; p<0.001) stood out as an independent predictor for MACE. CONCLUSIONS: In ACM patients, persistent drinking and cardiac MRI-defined myocardial scar were associated with adverse outcomes such as cardiac death, heart transplantation, hospitalization for heart failure or life-threatening ventricular arrhythmias.


Asunto(s)
Cardiomiopatía Alcohólica , Imagen por Resonancia Magnética , Humanos , Masculino , Persona de Mediana Edad , Femenino , Cardiomiopatía Alcohólica/diagnóstico por imagen , Pronóstico , Estudios Retrospectivos , Imagen por Resonancia Magnética/métodos , Factores de Riesgo , Imagen por Resonancia Cinemagnética/métodos , Medios de Contraste , Adulto
20.
Clin Radiol ; 79(7): 553-558, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38616474

RESUMEN

AIMS: To develop an auto-categorization system based on machine learning for three-dimensional magnetic resonance cholangiopancreatography (3D MRCP) to detect choledocholithiasis from healthy and symptomatic individuals. MATERIALS AND METHODS: 3D MRCP sequences from 254 cases with common bile duct (CBD) stones and 251 cases with normal CBD were enrolled to train the 3D Convolutional Neural Network (3D-CNN) model. Then 184 patients from three different hospitals (91 with positive CBD stone and 93 with normal CBD) were prospectively included to test the performance of 3D-CNN. RESULTS: With a cutoff value of 0.2754, 3D-CNN achieved the sensitivity, specificity, and accuracy of 94.51%, 92.47%, and 93.48%, respectively. In the receiver operating characteristic curve analysis, the area under the curve (AUC) for the presence or absence of CBD stones was 0.974 (95% CI, 0.940-0.992). There was no significant difference in sensitivity, specificity, and accuracy between 3D-CNN and radiologists. In addition, the performance of 3D-CNN was also evaluated in the internal test set and the external test set, respectively. The internal test set yielded an accuracy of 94.74% and AUC of 0.974 (95% CI, 0.919-0.996), and the external test set yielded an accuracy of 92.13% and AUC of 0.970 (95% CI, 0.911-0.995). CONCLUSIONS: An artificial intelligence-assisted diagnostic system for CBD stones was constructed using 3D-CNN model for 3D MRCP images. The performance of 3D-CNN model was comparable to that of radiologists in diagnosing CBD stones. 3D-CNN model maintained high performance when applied to data from other hospitals.


Asunto(s)
Pancreatocolangiografía por Resonancia Magnética , Imagenología Tridimensional , Redes Neurales de la Computación , Sensibilidad y Especificidad , Humanos , Pancreatocolangiografía por Resonancia Magnética/métodos , Masculino , Femenino , Persona de Mediana Edad , Imagenología Tridimensional/métodos , Adulto , Anciano , Cálculos Biliares/diagnóstico por imagen , Estudios Prospectivos , Conducto Colédoco/diagnóstico por imagen , Aprendizaje Automático , Coledocolitiasis/diagnóstico por imagen
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