Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.446
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Nature ; 627(8002): 73-79, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38418887

RESUMEN

By directly altering microscopic interactions, pressure provides a powerful tuning knob for the exploration of condensed phases and geophysical phenomena1. The megabar regime represents an interesting frontier, in which recent discoveries include high-temperature superconductors, as well as structural and valence phase transitions2-6. However, at such high pressures, many conventional measurement techniques fail. Here we demonstrate the ability to perform local magnetometry inside a diamond anvil cell with sub-micron spatial resolution at megabar pressures. Our approach uses a shallow layer of nitrogen-vacancy colour centres implanted directly within the anvil7-9; crucially, we choose a crystal cut compatible with the intrinsic symmetries of the nitrogen-vacancy centre to enable functionality at megabar pressures. We apply our technique to characterize a recently discovered hydride superconductor, CeH9 (ref. 10). By performing simultaneous magnetometry and electrical transport measurements, we observe the dual signatures of superconductivity: diamagnetism characteristic of the Meissner effect and a sharp drop of the resistance to near zero. By locally mapping both the diamagnetic response and flux trapping, we directly image the geometry of superconducting regions, showing marked inhomogeneities at the micron scale. Our work brings quantum sensing to the megabar frontier and enables the closed-loop optimization of superhydride materials synthesis.

2.
Ultrasound Obstet Gynecol ; 63(4): 536-543, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-37767652

RESUMEN

OBJECTIVES: Non-immune hydrops fetalis (NIHF) is the pathological accumulation of fluids in fetal compartments, without maternal isoimmunization. Fetal interventions (e.g. shunting, fetal paracentesis, fetal thoracocentesis, fetal pleurodesis) are used to alleviate fluid accumulations, but the outcome is uncertain because the underlying causes of NIHF vary. We aimed to explore the etiology and long-term outcome of NIHF after fetal intervention. METHODS: This was a retrospective review of fetuses with NIHF, defined by the presence of fetal ascites, pleural or pericardial effusion, skin edema or cystic hygroma, or a combination of these features, who underwent intervention at our institution during the period 2012-2021. Clinical surveillance, genetic analysis and viral infection screening were used to define the etiology. Chart reviews and telephone interviews were conducted to assess the long-term outcomes. RESULTS: In total, 55 fetuses were enrolled and 46 cases had final follow-up data after delivery. Etiology was identified in 33 cases, including four for which the underlying causes were not identified initially using small-gene-panel tests but which were later diagnosed with monogenic disorders by whole-exome sequencing (WES). Twenty-three cases with follow-up survived, having a follow-up period of 2-11 years at the time of writing, of which 17 were healthy. All 11 cases initially presenting as congenital chylothorax survived with favorable outcome. CONCLUSIONS: The etiologies of NIHF are heterogeneous, and the long-term (spanning 2-11 years) outcome of fetal intervention varies, according to the underlying etiology, with cases caused by congenital chylothorax having the best prognosis. Genome-wide tests, such as WES, may be helpful in determining the underlying condition in cases caused by a genetic disorder, and this may affect fetal therapy approaches in the future. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Quilotórax , Derrame Pleural , Embarazo , Femenino , Humanos , Hidropesía Fetal/etiología , Hidropesía Fetal/genética , Ascitis/diagnóstico por imagen , Ascitis/etiología , Estudios Retrospectivos , Quilotórax/complicaciones , Derrame Pleural/etiología , Derrame Pleural/complicaciones
3.
Phys Chem Chem Phys ; 26(11): 8695-8703, 2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-37947451

RESUMEN

Zintl-phase materials have attracted significant research interest owing to the interplay of magnetism and strong spin-orbit coupling, providing a prominent material platform for axion electrodynamics. Here, we report the single-crystal growth, structure, magnetic and electrical/thermal transport properties of the antiferromagnet layer Zintl-phase compound ß-EuIn2As2. Importantly, the new layered structure of ß-EuIn2As2, in rhombohedral (R3̄m) symmetry, contains triangular layers of Eu2+ ions. The in-plane resistivity ρ(H, T) measurements reveal metal behavior with an antiferromagnetic (AFM) transition (TN ∼ 23.5 K), which is consistent with the heat capacity Cp(H, T) and magnetic susceptibility χ(H, T) measurements. Negative MR was observed in the temperature range from 2 K to 20 K with a maximum MR ratio of 0.06. Unique 4f7J = S = 7/2 Eu2+ spins were supposed magnetically order along the c-axis. The Seebeck coefficient shows a maximum thermopower |Smax| of about 40 µV K-1. The kink around 23 K in the Seebeck coefficient originates from the effect of the antiferromagnetic phase on the electron band structure, while the pronounced thermal conductivity peak at around 10 K is attributed to the phonon-phonon Umklapp scattering. The results suggest that the Eu2+ spin arrangement plays an important role in the magnetic, electrical, and thermal transport properties in ß-EuIn2As2, which might be helpful for future potential technical applications.

4.
J Endocrinol Invest ; 2024 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-38787506

RESUMEN

PURPOSE: Thyroid cancer is one of a set of extrahepatic cancers that closely linked to metabolic dysfunction-associated fatty liver disease (MAFLD). However, the connection between MAFLD and the characteristics of papillary thyroid cancer (PTC) remains unexplored. METHODS: Between Jan 2020 and Oct 2022, surgical cases of PTC patients were examined at the first Affiliated Hospital of Wenzhou Medical University. Clinical data extracted from the electronic medical system underwent a rigorous comparison between two groups, classified based on MAFLD criteria, using logistic regression analysis. RESULTS: In this study of 4,410 PTC patients, 18.3% had MAFLD. MAFLD emerged as a distinct risk factor for lymph node metastasis (OR = 1.230, 95% CI 1.018-1.487) in this cohort, especially in females (OR = 1.321, 95% CI 1.026-1.702) and those with BMI ≥ 23 kg/m2 (OR = 1.232, 95% CI 1.004-1.511). The presence of MAFLD was found to significantly elevate the risk of BRAF V600E mutation in both subgroups characterized by FIB-4 score ≥ 1.3 (OR = 1.968, 95% CI 1.107-3.496) and BMI < 23 kg/m2 (OR = 2.584, 95% CI 1.012-6.601). Moreover, among the subset of individuals without non-alcoholic fatty liver disease (NAFLD), it was noted that MAFLD considerably increased the likelihood of tumor multifocality (OR = 1.697, 95% CI 1.111-2.592). Nevertheless, MAFLD did not exhibit any correlation with increased tumor size, extra-thyroidal extension (ETE), or later TNM stage in PTC. CONCLUSION: In this cross-sectional study, we discovered a significant association between MAFLD and increased occurrences of lymph node metastasis. Furthermore, MAFLD was linked to a higher chance of BRAF V600E mutation and the presence of multiple tumors in certain subgroups.

5.
J Eur Acad Dermatol Venereol ; 38(3): 583-593, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38391212

RESUMEN

BACKGROUND: Efficacy of the Janus kinase (JAK) inhibitor baricitinib for severe alopecia areata (AA) continuously increased over 52 weeks in two Phase 3 trials. There are limited long-term data on JAK inhibitors in AA. OBJECTIVES: To evaluate efficacy and safety of baricitinib for severe AA through 104 weeks of continuous therapy. METHODS: Integrated data from the BRAVE-AA1 and BRAVE-AA2 Phase 3 trials included adults with Severity of Alopecia Tool (SALT) scores ≥50 (≥50% scalp hair loss) randomized to and continuously treated with 2-mg or 4-mg baricitinib through Week 104. Patients who qualified to remain on continuous treatment included subjects who achieved SALT score ≤20 at Week 52 (Week-52 responders; 2-mg: N = 65; 4-mg: N = 129) and baricitinib 4-mg-treated patients who had SALT score >20 at Week 52 but achieved SALT score ≤20 at prior visit(s) and/or had significant improvement in eyebrow or eyelash hair growth relative to baseline by Week 52 (Week-52 mixed responders; N = 110). Week-104 outcomes included the proportion of patients achieving SALT score ≤20 (≤20% scalp hair loss). Data were censored after treatment discontinuation. RESULTS: Among baricitinib 4-mg-treated and baricitinib 2-mg-treated Week-52 responders, 90.7% and 89.2%, respectively, maintained SALT score ≤20 at Week 104. Among Week-52 mixed responders, 39.1% reached SALT score ≤20 by Week 104. Continued improvement in eyebrow and eyelash regrowth was observed across groups. The most frequent treatment-emergent adverse events were COVID-19, upper respiratory tract infection, headache, nasopharyngitis, acne, urinary tract infection and creatine phosphokinase increase. CONCLUSIONS: Baricitinib demonstrated a high level of maintenance of efficacy over 104 weeks in patients with severe AA. Efficacy increased in Week-52 mixed responders, illustrating that long-term treatment is necessary to observe maximum benefit in some patients. No new safety signals were observed.


Asunto(s)
Alopecia Areata , Azetidinas , Inhibidores de las Cinasas Janus , Purinas , Sulfonamidas , Adulto , Humanos , Alopecia/tratamiento farmacológico , Alopecia Areata/tratamiento farmacológico , Azetidinas/efectos adversos , Inhibidores de las Cinasas Janus/efectos adversos , Pirazoles/efectos adversos , Ensayos Clínicos Controlados Aleatorios como Asunto , Ensayos Clínicos Fase III como Asunto
6.
Rhinology ; 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38958021

RESUMEN

BACKGROUND: To establish whether bicanalicular silicone tube intubation is required during endoscopic dacryocystorhinostomy (En-DCR) for treating chronic dacryocystitis with a small lacrimal sac. METHODS: In total, this study enrolled 264 patients diagnosed with unilateral chronic dacryocystitis with small lacrimal sacs via computed tomography-dacryocystography that underwent En-DCR from March 2016-September 2020. Patients were randomized into two treatment groups, with those in group A undergoing tubes intubation and those in group B not undergoing this procedure. The tubes were removed 3 months post-operation in group A. Surgical outcomes and related complication rates were then compared. RESULTS: This study included 242 patients, including124 and 118 in groups A and B, respectively. At the three-month follow-up time point, 12.90% of patients in group A exhibited ostial granulation tissue, with this frequency with no differences observed in group B (11.86%). At 6 months post-surgery, 80.65% of patients in group A and 72.88% of patients in group B exhibited successful surgical outcomes, with no significant differences between groups. At 9 months postoperatively, the overall effective success rate was 60.74%, and the success rate was significantlyhigher in group A relative to group B (group A: 75.81%; group B: 44.92%). There were no failed patient outcomes observed as of the 12-month follow-up time point. CONCLUSIONS: While En-DCR-based treatment of chronic dacryocystitis in those with smalllacrimal sacs did not yield satisfactory outcomes with respect to the overall effective success rate, these results suggest that intraoperative intubation may improve success rates in long-term follow-up.

7.
Zhonghua Nei Ke Za Zhi ; 63(6): 605-612, 2024 Jun 01.
Artículo en Zh | MEDLINE | ID: mdl-38825930

RESUMEN

Objective: To observe the characteristics and differences of gut microbiota in asthma patients with different inflammatory types through metagenomic analysis. Methods: Adults aged ≥18 years who visited the Respiratory Clinic of Peking University Third Hospital from August 1, 2021 to August 31, 2022 and were primarily diagnosed with asthma were selected as the study subjects. Finally, 29 patients with stable asthma were included. Fresh fecal samples were collected and the fecal DNA was extracted for high-throughput 16sRNA sequencing of gut microbiota. The diversity and community structure of gut microbiota in different groups of asthma patients were compared, and the species differences were analyzed through random forest and LEfSe analysis. Results: There were sex-based differences in asthma patients with different types of inflammation, and the proportion of female patients was higher in neutrophilic asthma patients (χ2=4.14, P=0.042). There was no significant intergroup difference in the alpha diversity of gut microbiota among asthma patients with different inflammatory types, but there were significant differences in the microbiome. Patients with neutrophilic asthma had higher relative abundance of Bacillales (P=0.029) and Oscillospiraceae (P=0.015). In species LEfSe analysis, patients with eosinophilic asthma had a higher relative abundance of fungi. Conclusion: There are intergroup differences in the gut microbiota of asthma patients with different inflammation types, and fungi are biomarkers that distinguish the differences in gut microbiota between patients with eosinophilic asthma and neutrophilic asthma.


Asunto(s)
Asma , Heces , Microbioma Gastrointestinal , Inflamación , Humanos , Asma/microbiología , Heces/microbiología , Inflamación/microbiología , Femenino , Masculino , ARN Ribosómico 16S/genética , Adulto
8.
Zhonghua Fu Chan Ke Za Zhi ; 59(5): 375-382, 2024 May 25.
Artículo en Zh | MEDLINE | ID: mdl-38797567

RESUMEN

Objective: To investigate the variation of reference ranges of hemodynamic parameters in normal pregnancy and their relation to maternal basic characteristics. Methods: A total of 598 healthy pregnant women who underwent regular prenatal examination at the Third Affiliated Hospital of Guangzhou Medical University from January to December 2023 were prospectively enrolled, and noninvasive hemodynamic monitors were used to detect changes in hemodynamic parameters of the pregnant women with the week of gestation, including cardiac output (CO), stroke volume (SV), thoracic fluid content (TFC), systemic vascular resistance (SVR), mean arterial pressure (MAP), and heart rate (HR). Relationships between hemodynamic parameters and maternal basic characteristics, including age, height, and weight, were analyzed using restricted cubic spline. Results: (1) CO (r=0.155, P<0.001), TFC (r=0.338, P<0.001), MAP (r=0.204, P<0.001), and HR (r=0.352, P<0.001) were positively correlated with the week of gestation, and SV was negatively correlated with the week of gestation (r=-0.158, P<0.001). There was no significant correlation between SVR and gestational age (r=-0.051, P=0.258). (2) CO exhibited a positive correlation with maternal height and weight (all P<0.001). The taller and heavier of pregnant women, the higher their CO. A linear relationship was observed between maternal weight and SV, MAP and HR (all P<0.01). As maternal weight increased, SV, MAP and HR showed an upward trend. Furthermore, there was an inverse association between maternal age and SVR (P<0.001). (3) There was a significant nonlinear association observed between TFC and body mass index during pregnancy (P<0.05). Additionally, a nonlinear relationship was found between SVR and MAP in relation to maternal age (all P<0.05). Notably, when the age exceeded 31 years old, there was an evident upward trend observed in both SVR and MAP. Conclusions: The hemodynamic parameters of normal pregnant women are influenced by their height, body weight, and age. It is advisable to maintain a reasonable weight during pregnancy and give birth at an appropriate age.


Asunto(s)
Gasto Cardíaco , Frecuencia Cardíaca , Hemodinámica , Volumen Sistólico , Resistencia Vascular , Humanos , Femenino , Embarazo , Gasto Cardíaco/fisiología , Volumen Sistólico/fisiología , Resistencia Vascular/fisiología , Estudios Prospectivos , Frecuencia Cardíaca/fisiología , Edad Gestacional , Valores de Referencia , Adulto , Presión Sanguínea/fisiología , Presión Arterial/fisiología , Peso Corporal
9.
Zhonghua Bing Li Xue Za Zhi ; 53(2): 130-135, 2024 Feb 08.
Artículo en Zh | MEDLINE | ID: mdl-38281779

RESUMEN

Objective: To investigate the clinicopathological features and genetic characteristics of congenital cystic adenomatoid malformation (CCAM) of lung and CCAM associated lung cancer in adults. Methods: A total of 13 cases of CCAM of lung in adults, diagnosed from June 2015 to May 2023, were collected from the Department of Pathology, Shanghai Pulmonary Hospital, Tongji University School of Medicine, China. Their histopathological features were correlated with probable development into lung cancer. Next-generation sequencing was performed on the benign and malignant areas of all cases. Results: The pathological classification of all cases were of CCAM of lung type 1. There were 4 male and 9 female cases, age ranged from 18 to 65 years, with a mean age of 41 years. Six cases were accompanied by lung cancer, all of them were mucinous adenocarcinoma. Next-generation sequencing showed no gene mutation in 2 of the 13 cases; KRAS mutations in exon 2 were detected in 7 cases, in which there were 6 cases complicated with lung mucinous adenocarcinoma and no matter in the malignant or benign regions, the same case exhibited the same mutation sites in KRAS gene. Conclusions: CCAM of the lung is a congenital disease, and in adults, type 1 is most commonly found in the pathological classification, and it is often accompanied by cancer. Gene mutations are frequently detected in CCAM of the lung, KRAS being the most recurrent mutation which may play an important role in the carcinogenesis.


Asunto(s)
Adenocarcinoma del Pulmón , Adenocarcinoma Mucinoso , Malformación Adenomatoide Quística Congénita del Pulmón , Neoplasias Pulmonares , Adulto , Humanos , Masculino , Femenino , Adolescente , Adulto Joven , Persona de Mediana Edad , Anciano , Malformación Adenomatoide Quística Congénita del Pulmón/genética , Malformación Adenomatoide Quística Congénita del Pulmón/complicaciones , Malformación Adenomatoide Quística Congénita del Pulmón/diagnóstico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Proteínas Proto-Oncogénicas p21(ras)/genética , China , Pulmón/patología , Adenocarcinoma Mucinoso/patología
10.
Zhonghua Jie He He Hu Xi Za Zhi ; 47(1): 24-30, 2024 Jan 12.
Artículo en Zh | MEDLINE | ID: mdl-38062690

RESUMEN

Objective: To analyze the clinical data of a case of lung adenocarcinoma with Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) resistance transforming into sarcoma, and to conduct a literature review to improve the understanding of the resistance mechanism. Histological transformation is a unique form of acquired resistance of EGFR-TKIs in non-small cell lung cancer (NSCLC). Thereinto, the transformation of small cell carcinoma is more common, and the transformation of sarcoma is rarely reported. Methods: Clinicopathological data on the treatment process, pathological features, and clinical outcome of the patient with EGFR-TKIs-resistance lung adenocarcinoma transforming into sarcoma were collected. The literature was reviewed to analyze the pathogenetic mechanism for sarcomatoid carcinoma or sarcoma transformation after drug resistance of adenocarcinoma, as well as the clinical characteristics of the patients and the corresponding therapeutic schemes. Results: We reported a patient with lung adenocarcinoma who developed EGFR-T790M mutation after first-line treatment with icotinib and sarcoma transformation after second-line treatment with almonertinib. Chemotherapy, radioactive particle implantation, antiangiogenic therapy and immunotherapy were followed, but the results were unsatisfactory. There was no report of EGFR-TKIs-resistant lung adenocarcinoma transforming into sarcoma. Among the 14 reports of adenocarcinoma transforming into sarcomatoid carcinoma, 8 cases had EGFR mutation, 3 cases had ALK mutation, 2 cases had ROS1 mutation, and 1 case had no asscoiated sensitive mutation. The median survival of 14 patients with adenocarcinoma transforming to sarcomatoid carcinoma was only 3 months. Conclusions: Sarcoma transformation can be one of the forms of drug resistance in patients with lung adenocarcinoma with EGFR-TKIs. The prognosis of patients with adenocarcinoma after transformation into sarcoma is poor.


Asunto(s)
Adenocarcinoma del Pulmón , Adenocarcinoma , Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Sarcoma , Humanos , Adenocarcinoma/genética , Adenocarcinoma del Pulmón/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Resistencia a Antineoplásicos , Receptores ErbB/genética , Neoplasias Pulmonares/patología , Mutación , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Tirosina Quinasas/genética , Proteínas Proto-Oncogénicas/genética , Sarcoma/genética , Sarcoma/tratamiento farmacológico
11.
Zhonghua Wai Ke Za Zhi ; 62(5): 467-472, 2024 May 01.
Artículo en Zh | MEDLINE | ID: mdl-38548618

RESUMEN

Computational fluid dynamics (CFD) is an emerging technology applied in the field of cardiovascular medicine, which can obtain hemodynamic data by simulating the blood flow in the patient's heart for cardiac function assessment and disease diagnosis. Left ventricular function plays a key role in the occurrence and development of cardiomyopathies and coronary disease. CFD can reconstruct the left ventricular anatomic structures of patients to clarify pathophysiologic mechanisms and analyze hemodynamic parameters to evaluate left ventricular function, verify surgical efficacy, and guide surgical strategy, which has a positive effect on achieving early diagnosis and reducing mortality from cardiomyopathies and coronary disease. At present, there are still technical limitations in the large-scale clinical application of CFD, and various solutions are being developed and tested, and further improvement and refinement are needed.


Asunto(s)
Cardiomiopatías , Hidrodinámica , Función Ventricular Izquierda , Humanos , Cardiomiopatías/fisiopatología , Función Ventricular Izquierda/fisiología , Enfermedad Coronaria/fisiopatología , Simulación por Computador , Hemodinámica , Modelos Cardiovasculares
12.
Ann Oncol ; 34(5): 486-495, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36849097

RESUMEN

BACKGROUND: Early detection of cancer offers the opportunity to identify candidates when curative treatments are achievable. The THUNDER study (THe UNintrusive Detection of EaRly-stage cancers, NCT04820868) aimed to evaluate the performance of enhanced linear-splinter amplification sequencing, a previously described cell-free DNA (cfDNA) methylation-based technology, in the early detection and localization of six types of cancers in the colorectum, esophagus, liver, lung, ovary, and pancreas. PATIENTS AND METHODS: A customized panel of 161 984 CpG sites was constructed and validated by public and in-house (cancer: n = 249; non-cancer: n = 288) methylome data, respectively. The cfDNA samples from 1693 participants (cancer: n = 735; non-cancer: n = 958) were retrospectively collected to train and validate two multi-cancer detection blood test (MCDBT-1/2) models for different clinical scenarios. The models were validated on a prospective and independent cohort of age-matched 1010 participants (cancer: n = 505; non-cancer: n = 505). Simulation using the cancer incidence in China was applied to infer stage shift and survival benefits to demonstrate the potential utility of the models in the real world. RESULTS: MCDBT-1 yielded a sensitivity of 69.1% (64.8%-73.3%), a specificity of 98.9% (97.6%-99.7%), and tissue origin accuracy of 83.2% (78.7%-87.1%) in the independent validation set. For early-stage (I-III) patients, the sensitivity of MCDBT-1 was 59.8% (54.4%-65.0%). In the real-world simulation, MCDBT-1 achieved a sensitivity of 70.6% in detecting the six cancers, thus decreasing late-stage incidence by 38.7%-46.4%, and increasing 5-year survival rate by 33.1%-40.4%, respectively. In parallel, MCDBT-2 was generated at a slightly low specificity of 95.1% (92.8%-96.9%) but a higher sensitivity of 75.1% (71.9%-79.8%) than MCDBT-1 for populations at relatively high risk of cancers, and also had ideal performance. CONCLUSION: In this large-scale clinical validation study, MCDBT-1/2 models showed high sensitivity, specificity, and accuracy of predicted origin in detecting six types of cancers.


Asunto(s)
Ácidos Nucleicos Libres de Células , Neoplasias , Femenino , Humanos , Metilación de ADN , Estudios Prospectivos , Estudios Retrospectivos , Ácidos Nucleicos Libres de Células/genética , Neoplasias/diagnóstico , Neoplasias/genética , Biomarcadores de Tumor/genética , Detección Precoz del Cáncer
13.
Phys Rev Lett ; 130(22): 221802, 2023 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-37327426

RESUMEN

We present the results of a search for heavy QCD axions performed by the ArgoNeuT experiment at Fermilab. We search for heavy axions produced in the NuMI neutrino beam target and absorber decaying into dimuon pairs, which can be identified using the unique capabilities of ArgoNeuT and the MINOS near detector. This decay channel is motivated by a broad class of heavy QCD axion models that address the strong CP and axion quality problems with axion masses above the dimuon threshold. We obtain new constraints at a 95% confidence level for heavy axions in the previously unexplored mass range of 0.2-0.9 GeV, for axion decay constants around tens of TeV.


Asunto(s)
Tetranitrato de Pentaeritritol , Argón
14.
Ultrasound Obstet Gynecol ; 61(2): 215-223, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-35638228

RESUMEN

OBJECTIVES: Most human in-vivo placental imaging techniques are unable to distinguish and characterize various placental compartments, such as the intervillous space (IVS), placental vessels (PV) and placental tissue (PT), limiting their specificity. We describe a method that employs T2* and diffusion-weighted magnetic resonance imaging (MRI) data to differentiate automatically placental compartments, quantify their oxygenation properties and identify placental lesions (PL) in vivo. We also investigate the association between placental oxygenation patterns and fetal brain oxygenation. METHODS: This was a prospective study conducted between 2018 and 2021 in which dual-contrast clinical MRI data (T2* and diffusion-weighted MRI) were acquired from patients between 20 and 38 weeks' gestation. We trained a fuzzy clustering method to analyze T2* and diffusion-weighted MRI data and assign placental voxels to one of four clusters, based on their distinct imaging domain features. The new method divided automatically the placenta into IVS, PV, PT and PL compartments and characterized their oxygenation changes throughout pregnancy. RESULTS: A total of 27 patients were recruited, of whom five developed pregnancy complications. Total placental oxygenation level and T2* did not demonstrate a statistically significant temporal correlation with gestational age (GA) (R2 = 0.060, P = 0.27). In contrast, the oxygenation level reflected by T2* values in the placental IVS (R2 = 0.51, P = 0.0002) and PV (R2 = 0.76, P = 1.1 × 10-7 ) decreased significantly with advancing GA. Oxygenation levels in the PT did not show any temporal change during pregnancy (R2 = 0.00044, P = 0.93). A strong spatial-dependent correlation between PV oxygenation level and GA was observed. The strongest negative correlation between PV oxygenation and GA (R2 = 0.73, P = 4.5 × 10-7 ) was found at the fetal-vessel-dominated region close to the chorionic plate. The location and extent of the placental abnormality were automatically delineated and quantified in the five women with clinically confirmed placental pathology. Compared to the averaged total placental oxygenation, placental IVS oxygenation level best reflected fetal brain oxygenation level during fetal development. CONCLUSION: Based on clinically feasible dual-MRI, our method enables accurate spatiotemporal quantification of placental compartment and fetal brain oxygenation across different GAs. This information should improve our knowledge of human placenta development and its relationship with normal and abnormal pregnancy. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Enfermedades Placentarias , Complicaciones del Embarazo , Embarazo , Femenino , Humanos , Placenta/diagnóstico por imagen , Placenta/patología , Estudios Prospectivos , Enfermedades Placentarias/diagnóstico por imagen , Enfermedades Placentarias/patología , Imagen por Resonancia Magnética/métodos , Placentación , Complicaciones del Embarazo/patología , Encéfalo/diagnóstico por imagen
15.
Clin Radiol ; 78(6): 421-429, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37024359

RESUMEN

AIM: To investigate the "sub-aortic complex (SAC)", a new cardiac magnetic resonance imaging (CMRI)-derived parameter, for the evaluation of left ventricular (LV) outflow tract (LVOT) obstruction in patients with hypertrophic cardiomyopathy (HCM), compared with conventional CMRI parameters and Doppler echocardiography. MATERIALS AND METHODS: A total of 157 consecutive patients with HCM were recruited retrospectively. The patients were divided into two groups, 87 with LVOT obstruction and 70 without obstruction. The SAC was defined as a specific anatomical SAC affecting the LVOT, which were measured on the LV three-chamber steady-state free precession (SSFP) cine image at the end-systolic phase. The relations between the existence and severity of obstruction and SAC index (SACi) were evaluated using Pearson's correlation coefficient, receiver operating characteristic (ROC) curves, and logistic regression. RESULTS: The SACs were significantly different between the obstructive and non-obstructive groups. The ROC curves indicated that the SACi was able to discriminate obstructive and non-obstructive patients with the best predictive accuracy (AUC = 0.949, p<0.001). The SACi was an independent predictor of LVOT obstruction and there was a significant negative correlation between resting LVOT pressure gradient and SACi (r=0.72 p<0.001). In the subgroup of patients with or without severe basal septal hypertrophy, the SACi was still able to predict LVOT obstruction with excellent diagnostic accuracy (AUC = 0.944 and 0.948, p<0.001, respectively). CONCLUSION: The SAC is a reliable and straightforward CMRI marker for assessing LVOT obstruction. It is more effective than CMRI two-dimensional flow in diagnosing the severity of obstruction in patients with HCM.


Asunto(s)
Cardiomiopatía Hipertrófica , Imagen por Resonancia Cinemagnética , Humanos , Estudios Retrospectivos , Imagen por Resonancia Cinemagnética/métodos , Ecocardiografía Doppler , Imagen por Resonancia Magnética , Hemodinámica
16.
J Chem Phys ; 158(9): 094502, 2023 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-36889943

RESUMEN

The present work contributes to the development of the shadowgraph method for its routine application for an accurate determination of the Fick diffusion coefficient D11 of binary fluid mixtures. In this context, measurement and data evaluation strategies for thermodiffusion experiments where confinement and advection are potentially present are elaborated by studying two binary liquid mixtures with positive and negative Soret coefficients, i.e., 1,2,3,4-tetrahydronaphthalene/n-dodecane and acetone/cyclohexane. For obtaining accurate D11 data, the dynamics of non-equilibrium fluctuations in concentration is analyzed considering recent theory by data evaluation procedures that are demonstrated to be suitable for different experimental configurations.

17.
J Chem Phys ; 159(7)2023 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-37594072

RESUMEN

The present work demonstrates the accessibility of the Fick diffusion coefficient D11 and/or the thermal diffusivity a of the binary mixtures dicyclohexylmethane/diphenylmethane, n-hexane/carbon dioxide, 1-hexanol/carbon dioxide, and methane/propane by the analysis of the dynamics of non-equilibrium fluctuations using the shadowgraph method. It is evidenced that D11 and a can be simultaneously determined for binary mixtures with Lewis numbers Le = a/D11 ranging over two orders of magnitude down to Le ≈ 5 or in the presence of minor advection for binary mixtures possessing a negative Soret coefficient in the investigated temperature and pressure ranges from (298.15 to 473.15) K and from about (0.5 to 25) MPa. The determined diffusivities are compared with those measured by heterodyne dynamic light scattering or obtained from the literature, with a focus on achievable uncertainties. By this comparison, it is shown that the determination of a by the shadowgraph method was hindered by mode-coupling effects for Le ≈ 5, whereas a determination of D11 was always possible for mixtures with Le ≥ 5. Furthermore, it is demonstrated that even in the presence of solutal advection, the description of the purely diffusive behavior of non-equilibrium fluctuations in concentration remains valid.

18.
J Endocrinol Invest ; 46(3): 509-522, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36115894

RESUMEN

BACKGROUND: Circular RNAs (circRNAs) are non-coding RNAs that have essential regulatory roles in the development of various tumors. This study explored whether circRNAs are involved in the progression of papillary thyroid carcinoma (PTC). METHODS: Differentially expressed circRNAs (DECs) in four pairs of PTC and matched normal thyroid tissues were screened using a circRNA microarray. The potential functions of dysregulated circRNAs were predicted by bioinformatic analyses. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was used to determine hsa_circ_0082003 expression in 80 pairs of PTC and matched normal thyroid tissues. Cell counting kit-8, colony formation, wound healing, and Transwell assays were performed to evaluate the biological functions of hsa_circ_0082003 in PTC cells. The role of hsa_circ_0082003 in PTC tumorigenesis in vivo was validated in nude mice. RESULTS: In total, 3150 DECs (2317 upregulated and 833 downregulated) were identified. Pathway enrichment analyses indicated that the dysregulated circRNAs may play roles in PTC development. RT-qPCR validation demonstrated that hsa_circ_0082003 expression was significantly increased in PTC tissues and correlated with poor clinicopathological parameters. Receiver operating characteristic curve analysis showed that hsa_circ_0082003 had good performance for diagnosing PTC and judging whether it was accompanied by lymph node metastasis. Knockdown of hsa_circ_0082003 inhibited PTC cell proliferation, migration, and invasion. Tumor formation assays in vivo showed that downregulation of hsa_circ_0082003 significantly suppressed the growth of PTC. CONCLUSION: Hsa_circ_0082003 may serve as a novel diagnostic biomarker and potential therapeutic target for PTC.


Asunto(s)
ARN Circular , Neoplasias de la Tiroides , Animales , Ratones , Cáncer Papilar Tiroideo/patología , ARN Circular/genética , Carcinógenos , Ratones Desnudos , Neoplasias de la Tiroides/patología
19.
Health Educ Res ; 38(6): 537-547, 2023 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-37436823

RESUMEN

This study compares the impact of pictorial health warning labels (HWLs) and their placements on waterpipe parts (device, tobacco and charcoal packages) on health communication outcomes between waterpipe smokers and nonsmokers in Lebanon. An online randomized crossover experimental study was conducted among young adults (n = 403, August 2021) who observed three conditions of HWLs: pictorial HWLs on the tobacco package, pictorial HWLs on all waterpipe's parts and text-only HWL on the tobacco package in random order. Participants completed post-exposure assessments of health communication outcomes after each image. Using linear mixed models, we examined the differences in the effect of HWL conditions on several outcomes (i.e. warning reactions) between waterpipe smokers and nonsmokers, controlling for confounders (i.e. age, sex). Nonsmokers reported greater attention (ß = 0.54 [95% confidence interval: 0.25-0.82]), cognitive elaboration (0.31 [0.05-0.58]) and social interaction (0.41 [0.18-0.65]) for pictorial HWLs on the tobacco packages than text-only compared with smokers. Pictorial HWLs on three parts versus one part elicited higher cognitive reactions and perceived message effectiveness in nonsmokers compared with waterpipe smokers. These findings provide valuable information for policymakers about the potential of implementing HWLs specific to waterpipes to prevent their use among young adults and limit tobacco-related morbidity and mortality in Lebanon.


Asunto(s)
Cese del Hábito de Fumar , Productos de Tabaco , Fumar en Pipa de Agua , Humanos , Adulto Joven , Fumadores/psicología , Cese del Hábito de Fumar/métodos , No Fumadores , Líbano , Fumar en Pipa de Agua/efectos adversos , Etiquetado de Productos/métodos
20.
Childs Nerv Syst ; 39(11): 3163-3168, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-36997725

RESUMEN

OBJECTIVE: Conventional pediatric spine MRI protocols have multiple sequences resulting in long acquisition times. Sedation is consequently required. This study evaluates the diagnostic capability of a limited MRI spine protocol for selected common pediatric indications. METHODS: Spine MRIs at CHEO between 2017 and 2020 were reviewed across pediatric patients younger than four years old. Two blinded neuroradiologists reviewed limited scan sequences, and results were independently compared to previously reported findings from the complete imaging series. T2 sagittal sequences from the craniocervical junction to sacrum and T1 axial sequence of the lumbar spine constitute the short protocol, with the outcomes of interest being cerebellar ectopia, syrinx, level of conus, filum < 2 mm, fatty filum, and spinal dysraphism. RESULTS: A total of 105 studies were evaluated in 54 male and 51 female patients (mean age 19.2 months). The average combined scan time of the limited sequences was 15 min compared to 35 min for conventional protocols (delta = 20 min). The average percent agreement between full and limited sequences was > 95% in all but identifying a filum < 2 mm, where the percent agreement was 87%. Using limited MR sequences had high sensitivity (> 0.91) and specificity (> 0.99) for the detection of cerebellar ectopia, syrinx, fatty filum, and spinal dysraphism. CONCLUSION: This study demonstrates that selected spinal imaging sequences allow for consistent and accurate diagnosis of specific clinical conditions. A limited spine imaging protocol has potential as a screening test to reduce the need for full-sequence MRI scans. Further work is needed to determine utility of selected imaging for other clinical indications.


Asunto(s)
Defectos del Tubo Neural , Disrafia Espinal , Siringomielia , Humanos , Masculino , Femenino , Niño , Lactante , Preescolar , Estudios Retrospectivos , Imagen por Resonancia Magnética/métodos , Vértebras Lumbares , Región Lumbosacra
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA