Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Neuropathology ; 44(4): 292-297, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38410881

RESUMEN

Adamantinomatous craniopharyngioma is a grade 1 tumor that arises in a sellar/suprasellar location. Despite being a grade 1 tumor, there is high recurrence and endocrinal insufficiency. Malignancy arising in craniopharyngioma is extremely rare, has a dismal prognosis, and is currently not included as a separate entity in the World Health Organization Classification of Central Nervous System 5th edition. Here we describe a case of adamantinomatous craniopharyngioma and its malignant counterpart. The malignant part had unique histomorphology and basaloid cells with pseudoglandular architecture and a myxoid background. It bore a striking resemblance to adenoid cystic carcinoma. Both the benign and malignant counterparts were beta-catenin and SOX-2 positive, providing proof of the malignant part arising from the benign part. Tumors like squamous cell carcinoma and odontogenic ghost cell carcinoma have been described in cranipharyngioma. This case study is the first to describe this unique morphology of adenoid cystic carcinoma-like features. The possibility of adenoid cystic carcinoma was excluded by immunohistochemistry.


Asunto(s)
Craneofaringioma , Neoplasias Hipofisarias , Humanos , Craneofaringioma/patología , Neoplasias Hipofisarias/patología , Masculino , Carcinoma Adenoide Quístico/patología , Adulto , Femenino
2.
Neuropathology ; 44(4): 314-318, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38409890

RESUMEN

Astroblastoma is an uncommon circumscribed glial tumor mostly involving the cerebral hemisphere. The characteristic molecular alteration is meningioma (disrupted in balanced translocation) 1 (MN1) rearrangement. No definite World Health Organization grade has been assigned as both low- and high-grade tumors are known to occur. Tumors in the spine are extremely rare; to date only three cases have been reported in the literature. A vigilant microscopy and ancillary testing aid in diagnosis when the tumors present in unusual locations, as in our case. The prompt differentiation of this tumor from its mimickers is a mandate as modalities of management are different and not clearly established.


Asunto(s)
Neoplasias Neuroepiteliales , Humanos , Neoplasias Neuroepiteliales/patología , Neoplasias Neuroepiteliales/genética , Neoplasias Neuroepiteliales/diagnóstico por imagen , Preescolar , Proteínas Supresoras de Tumor/genética , Neoplasias de la Médula Espinal/patología , Neoplasias de la Médula Espinal/genética , Neoplasias de la Médula Espinal/diagnóstico por imagen , Masculino , Femenino , Transactivadores
3.
Ann Diagn Pathol ; 72: 152318, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38733671

RESUMEN

BACKGROUND: Pilocytic astrocytoma (PAs) represents a significant portion of childhood primary brain tumors, with distinct histological and radiological features. The prevalence of KIAA1549::BRAF fusion in PAs has been well-established, this study aims to assess the prevalence of KIAA1549::BRAF fusions and explore their associations with tumor characteristics, radiological findings, and patient outcomes in PAs. METHODS: Histologically confirmed cases of PAs from a 5-year period were included in the study. Demographic, histopathological, and radiological data were collected, and immunohistochemistry was performed to characterize tumor markers. FISH and qRT-PCR assays were employed to detect KIAA1549::BRAF fusions. Statistical analyses were conducted to examine associations between fusion status and various other parameters. RESULTS: Histological analysis revealed no significant differences in tumor features based on fusion status. However, younger age groups showed higher fusion prevalence. Radiologically, fusion-positive cases were distributed across different tumor subtypes SE, CWE and NCWE. Survival analysis did not demonstrate a significant impact of fusion status on overall survival, however most cases with recurrence and death harboured KIAA1549::BRAF fusion. Of 200 PAs, KIAA1549::BRAF fusions were detected in 64 % and 74 % of cases via qRT-PCR and FISH, respectively. Concordance between the two platforms was substantial (86 %). CONCLUSION: KIAA1549::BRAF fusions are prevalent in PAs and can be reliably detected using both FISH and qRT-PCR assays. Cost considerations suggest qRT-PCR as a more economical option for fusion detection in routine clinical practice.


Asunto(s)
Astrocitoma , Biomarcadores de Tumor , Neoplasias Encefálicas , Proteínas de Fusión Oncogénica , Proteínas Proto-Oncogénicas B-raf , Humanos , Femenino , Masculino , Niño , Astrocitoma/genética , Astrocitoma/patología , Preescolar , Proteínas de Fusión Oncogénica/genética , Proteínas Proto-Oncogénicas B-raf/genética , Adolescente , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patología , Lactante , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Inmunohistoquímica/métodos , Hibridación Fluorescente in Situ/métodos , Adulto Joven
4.
Curr Microbiol ; 78(8): 2961-2969, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34081183

RESUMEN

In the present study, a plant growth-promoting bacterium isolated from contaminated in vitro-grown Basilicum polystachyon (L.) Moench, an herbaceous plant, was studied and identified as Acinetobacter strain SuKIC24 based on the 16S rRNA gene sequence analysis. The results revealed that the identified strain exhibited a strong ability to solubilize the phosphate with phosphate solubilization index of 4.0 and produced 387 µg/ml of soluble phosphate in Pikovskaya media after 7 days of incubation, whereas zinc solubilization efficacy was determined to be 175%. Reversed-phase high-performance liquid chromatography (RP-HPLC) analysis revealed that the bacterium strain produced 77.36 µg/ml of indole-3-acetic acid. Plant inoculated with the bacterium strain was found to demonstrate a significant increase in height of B. polystachyon as compared to the control plant. The present findings indicated that the identified bacterium strain might act as plant growth-promoting bacterium (PGPB).


Asunto(s)
Acinetobacter , Acinetobacter/genética , Bacterias , Desarrollo de la Planta , ARN Ribosómico 16S/genética , Microbiología del Suelo
5.
Phys Chem Chem Phys ; 22(41): 23707-23724, 2020 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-33057524

RESUMEN

This paper presents the dynamics of confined water and its interplay with alkali cations in disordered sodium aluminosilicate hydrate (N-A-S-H) gel using reactive force field molecular dynamics. N-A-S-H gel is the primary binding phase in geopolymers formed via alkaline activation of fly ash. Despite attractive mechanical properties, geopolymers suffer from durability issues, particularly the alkali leaching problem which has motivated this study. Here, the dynamics of confined water and the mobility of alkali cations in N-A-S-H is evaluated by obtaining the evolution of mean squared displacements and Van Hove correlation function. To evaluate the influence of the composition of N-A-S-H on the water dynamics and diffusion of alkali cations, atomistic structures of N-A-S-H with Si/Al ratio ranging from 1 to 3 are constructed. It is observed that the diffusion of confined water and sodium is significantly influenced by the Si/Al ratio. The confined water molecules in N-A-S-H exhibit a multistage dynamic behavior where they can be classified as mobile and immobile water molecules. While the mobility of water molecules gets progressively restricted with an increase in Si/Al ratio, the diffusion coefficient of sodium also decreases as the Si/Al ratio increases. The diffusion coefficient of water molecules in the N-A-S-H structure exhibits a lower value than those of the calcium-silicate-hydrate (C-S-H) structure. This is mainly due to the random disordered structure of N-A-S-H as compared to the layered C-S-H structure. To further evaluate the influence of water content in N-A-S-H, atomistic structures of N-A-S-H with water contents ranging from 5-20% are constructed. Qn distribution of the structures indicates significant depolymerization of N-A-S-H structure with increasing water content. Increased conversion of Si-O-Na network to Si-O-H and Na-OH components with an increase in water content helps explain the alkali-leaching issue in fly ash-based geopolymers observed macroscopically. Overall, the results in this study can be used as a starting point towards multiscale simulation-based design and development of durable geopolymers.

6.
Phys Rev Lett ; 121(14): 143601, 2018 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-30339447

RESUMEN

We show that strongly correlated photon transport can be observed in waveguides containing optically dense ensembles of emitters. Remarkably, this occurs even for weak coupling efficiencies. Specifically, we compute the photon transport properties through a chirally coupled system of N two-level systems driven by a weak coherent field, where each emitter can also scatter photons out of the waveguide. The photon correlations arise due to an interplay of nonlinearity and coupling to a loss reservoir, which creates a strong effective interaction between transmitted photons. The highly correlated photon states are less susceptible to losses than uncorrelated photons and have a power-law decay with N. This is described using a simple universal asymptotic solution governed by a single scaling parameter which describes photon bunching and power transmission. We show numerically that, for randomly placed emitters, these results hold even in systems without chirality. The effect can be observed in existing tapered fiber setups with trapped atoms.

7.
Phys Rev Lett ; 118(14): 140501, 2017 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-28430479

RESUMEN

We propose an efficient light-matter interface at optical frequencies between a single photon and a superconducting qubit. The desired interface is based on a hybrid architecture composed of an organic molecule embedded inside an optical waveguide and electrically coupled to a superconducting qubit placed near the outside surface of the waveguide. We show that high fidelity, photon-mediated, entanglement between distant superconducting qubits can be achieved with incident pulses at the single photon level. Such a low light level is highly desirable for achieving a coherent optical interface with superconducting qubit, since it minimizes decoherence arising from the absorption of light.

8.
Opt Lett ; 40(10): 2229-32, 2015 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-26393706

RESUMEN

We propose a novel scheme for efficient Raman sub-harmonic generation in a system of inhomogeneously broadened atomic vapor with atoms in a closed three-level Λ-configuration. The key feature underlying Raman sub-harmonics generation is microwave-induced hyperfine coherence between the two lower level metastable states. We show explicitly how the amplitude and phase of the microwave field generate controllable spectral amplitudes of Raman sub-harmonics. Our scheme is viable in currently available atomic vapor cells thereby opening the way for efficient sub-harmonic generation in standard experimental setups.

9.
Indian J Surg Oncol ; 15(1): 181-184, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38511032

RESUMEN

Epithelioid hemangioma also known as angio-lymphoid hyperplasia with eosinophilia is a rare benign vascular neoplasm of unknown etiology. It very rarely involves the nasal cavity. It always poses a diagnostic challenge for clinicians and is usually misdiagnosed as Kimura's, IgG4-related disease, or malignant vascular tumors. The present case report describes an extremely rare presentation of epithelioid hemangioma inside the left nasal cavity causing complete obstruction and nasal septal deviation towards the right side in a young male. Hematoxylin and eosin-stained sections depicted a lobular proliferation of small capillary-sized vessels lined by plump epithelioid endothelial cells surrounding central vessels and scattered around them. These cells had abundant eosinophilic to amphophilic cytoplasm and enlarged nuclei with fine chromatin and central nucleoli. On immunohistochemistry, CD34 and CD31 highlighted the vascular proliferation and epithelioid endothelial cells. Erythroblast transformation-specific (ETS)-related gene (ERG) showed strong nuclear positivity in neoplastic plump epithelioid endothelial cells. EH is a benign vascular proliferation, but a high chance of recurrence is seen if complete resection is not done. As a result, the treatment of choice is complete surgical excision with clear margins. The case highlights a non-conventional presentation of epithelioid hemangioma and the importance of histomorphological features in diagnosing this entity.

10.
BMJ Case Rep ; 17(4)2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38649243

RESUMEN

A male in his 20s, a tobacco chewer, presented to the outpatient department with a history of painless, slowly progressive swelling in the floor of the mouth. After a thorough history and clinical examination, MRI was done and the tumour was completely excised. Histopathological examination revealed the mass to be a solitary fibrous tumour, confirmed with immunohistochemical markers. On subsequent follow-ups, the patient was found to be asymptomatic with no clinical signs of recurrence.


Asunto(s)
Imagen por Resonancia Magnética , Suelo de la Boca , Neoplasias de la Boca , Tumores Fibrosos Solitarios , Humanos , Masculino , Tumores Fibrosos Solitarios/cirugía , Tumores Fibrosos Solitarios/patología , Tumores Fibrosos Solitarios/diagnóstico por imagen , Tumores Fibrosos Solitarios/diagnóstico , Neoplasias de la Boca/patología , Neoplasias de la Boca/cirugía , Neoplasias de la Boca/diagnóstico , Neoplasias de la Boca/diagnóstico por imagen , Suelo de la Boca/patología , Adulto , Adulto Joven
11.
Materials (Basel) ; 17(2)2024 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-38276452

RESUMEN

In this study, alder, spruce, and beech woods were used for homogeneous symmetric, inhomogeneous symmetric (combined) and inhomogeneous non-symmetric glued laminated timber (glulam) beams glued with resorcinol phenol formaldehyde (RPF) adhesive. The aim of this paper is to determine and compare the modulus of elasticity of glulam beams using three methods, i.e., analytical calculation, numerical model (FEM) and experimental testing. As an additional characteristic, the bending strength (MOR) of the beams was determined during experimental testing. Analytical calculation was used to calculate the modulus of elasticity (MOE) of glued laminated timber based on the knowledge of the modulus of elasticity of solid wood and to estimate the location of the neutral axis during bending. According to calculations, for symmetrical combinations, the deviation from the real neutral axis does not exceed 5%. In the case of the modulus of elasticity, the deviation is an average of 4.1% from that of the actual measured beams. The numerical model includes finite element modelling, where the deflection of the modelled beams can be calculated with a deviation of up to 10%. The last method was experimental testing of glued beams using four-point bending, in which, among homogeneous beams, beech glulam beams achieved the highest MOE and MOR, while alder glulam beams achieved the lowest. The combination of wood species resulted in an increase in both MOE and MOR compared to homogeneous spruce and alder beams.

12.
J Mycol Med ; 34(2): 101467, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38432117

RESUMEN

A 3-year-old boy presented with acute headache, vomiting and right focal clonic seizures without history of fever, joint pain or altered sensorium. Neuroimaging showed multifocal contrast enhancing lesions with significant perilesional edema. CECT chest and abdomen showed multiple variable sized nodules in the lungs and hypodense lesion in liver with mesenteric lymphadenopathy. There was persistent eosinophilia with maximum upto 35 %. Liver biopsy and brain biopsy revealed Cladophialophora bantiana. He was treated with IV liposomal amphotericin and voriconazole for 6 weeks with repeat neuroimaging showing more than 50 % resolution of the intracranial lesions. He was transitioned to oral combination of flucytosine and voriconazole. At 14 months follow-up, he remained symptom free with complete radiological resolution of the lesions and no eosinophilia. High suspicion, an aggressive approach in obtaining microbiological diagnosis and timely combination antifungal therapy may give satisfactory outcome without surgery.


Asunto(s)
Anfotericina B , Antifúngicos , Ascomicetos , Inmunocompetencia , Feohifomicosis , Humanos , Masculino , Preescolar , Antifúngicos/uso terapéutico , Ascomicetos/aislamiento & purificación , Feohifomicosis/microbiología , Feohifomicosis/diagnóstico , Feohifomicosis/tratamiento farmacológico , Anfotericina B/uso terapéutico , Voriconazol/uso terapéutico , Flucitosina/uso terapéutico , Flucitosina/administración & dosificación
13.
World Neurosurg ; 184: e486-e493, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38307196

RESUMEN

BACKGROUND: Papillary tumors of pineal region (PTPR) comprise a very rare subset of pineal region tumors that have been recently described. Literature on the management and outcome of PTPR is scarce owing to the rarity of these tumors. To address this lacuna, we analyzed our experience in management of PTPR. METHODS: We retrospectively analyzed the outcome of 11 patients with histopathologically proven PTPR who underwent surgical excision at our center. RESULTS: Mean patient age was 33.3 years (range, 12-45 years), and male-to-female ratio was 1.75:1. Headache was the most common presentation followed by visual disturbances, altered sensorium, Perinaud syndrome, and seizures. Cerebrospinal fluid diversion was required in 6 patients. Krause approach was the most common approach used for tumor excision (9/11 cases). There was no perioperative mortality. Two patients were lost to follow-up. In the remaining 9 patients, the average follow-up period was 45 months (range, 12-79 months). On first postoperative magnetic resonance imaging, 8 patients showed no evidence of residual tumor (gross total resection), while 1 patient had small residual tumor (near-total resection) that remained stable during follow-up. Four patients underwent adjuvant chemoradiotherapy. None of the patients developed recurrence during follow-up. CONCLUSIONS: PTPR are a rare subgroup of pineal region tumors with distinct cells of origin but presentation similar to other pineal region tumors. Surgical resection constitutes the mainstay of management, and the extent of resection appears to be the most important determinant of prognosis. The role of adjuvant therapy still needs to be determined.


Asunto(s)
Neoplasias Encefálicas , Glándula Pineal , Pinealoma , Humanos , Masculino , Femenino , Niño , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Estudios Retrospectivos , Neoplasia Residual/patología , Glándula Pineal/diagnóstico por imagen , Glándula Pineal/cirugía , Glándula Pineal/patología , Pinealoma/cirugía , Pinealoma/patología , Neoplasias Encefálicas/patología
14.
Pathol Res Pract ; 258: 155347, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38763090

RESUMEN

Pediatric high grade gliomas have undergone remarkable changes in recent time with discovery of new molecular pathways. They have been added separately in current WHO 2021 blue book. All the entities show characteristic morphology and immunohistochemistry. Methylation data correctly identifies these entities into particular group of clusters. The pediatric group high grade glioma comprises- Diffuse midline glioma, H3K27-altered; Diffuse hemispheric glioma, H3G34-mutant; Diffuse pediatric-type high-grade glioma, H3-wild type & IDH-wild type; Infant hemispheric glioma and Epithelioid glioblastoma/Grade 3 pleomorphic xanthoastrocytoma and very rare IDH-mutant astrocytoma. However it is not always feasible to perform these molecular tests where cost-effective diagnosis is a major concern. Here we discuss the major entities with their characteristic histopathology, immunohistochemistry and molecular findings that may help to reach to suggest the diagnosis and help the clinician for appropriate treatment strategies. We have also made a simple algorithmic flow chart integrated with histopathology, immunohistochemistry and molecular characteristics for better understanding.


Asunto(s)
Neoplasias Encefálicas , Glioma , Inmunohistoquímica , Humanos , Glioma/patología , Glioma/genética , Glioma/metabolismo , Glioma/diagnóstico , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/metabolismo , Inmunohistoquímica/métodos , Niño , Biomarcadores de Tumor/análisis , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Clasificación del Tumor
15.
Environ Health Insights ; 17: 11786302231201259, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37808962

RESUMEN

Along with expanding urbanization and industrialization, environmental pollution which negatively affects the surroundings, has been rising quickly. As a result, induces heavy metal contamination which poses a serious threat to living organisms of aquatic and soil ecosystems. Therefore, they are a need to ameliorate the effects cost by cost pollution on the environment. In this review, we explore methods employed to mitigate the effects caused by heavy metals on the environment. Many techniques employed to manage environmental pollution are tedious and very costly, necessitating the use of alternative management strategies to resolve this challenge. In this concept, bioremediation is viewed as a future technique, due to its environmental friendliness and cost-effective measures aligned with sustainable or climate-smart agriculture to manage contaminants in the environment. The technique involves the use of living entities such as bacteria, fungi, and plants to deteriorate toxic substances from the rhizosphere. Currently, bioremediation is thought to be the most practical, dependable, environmentally benign, and long-lasting solution. Although bioremediation involves different techniques, they are still a need to find the most efficient method for removing toxic substances from the environment. This review focuses on the origins of heavy metal pollution, delves into cost-effective and green technological approaches for eliminating heavy metal pollutants from the environment, and discusses the impact of these pollutants on human health.

16.
Plants (Basel) ; 13(1)2023 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-38202406

RESUMEN

The global industrial revolution has led to a substantial rise in heavy metal levels in the environment, posing a serious threat to nature. Plants synthesize phenolic compounds under stressful conditions, which serve as protective agents against oxidative stress. Basilicum polystachyon (L.) Moench is an herbaceous plant of the Lamiaceae family. Some species within this family are recognized for their capacity to remediate sites contaminated with heavy metals. In this study, the effects of mercury (II) chloride and lead (II) nitrate on the in vitro propagation of B. polystachyon were investigated. Shoot tips from in vitro plantlets were cultured in Murashige and Skoog's (MS) media with heavy metals ranging from 1 to 200 µM to induce abiotic stress and enhance the accumulation of phenolic compounds. After three weeks, MS medium with 1 µM of lead (II) supported the highest shoot multiplication, and the maximum number of roots per explant was found in 100 µM of lead (II), whereas a higher concentration of heavy metals inhibited shoot multiplication and root development. The plantlets were hardened in a greenhouse with a 96% field survival rate. Flame atomic absorption spectroscopy (FAAS) was used to detect heavy metal contents in plant biomass. At both 200 µM and 50 µM concentrations, the greatest accumulation of mercury (II) was observed in the roots (16.94 ± 0.44 µg/g) and shoots (17.71 ± 0.66 µg/g), respectively. Similarly, lead (II) showed the highest accumulation in roots (17.10 ± 0.54 µg/g) and shoots (7.78 ± 0.26 µg/g) at 200 µM and 50 µM exposures, respectively. Reverse-phase high-performance liquid chromatography (RP-HPLC) identified and quantified various phenolic compounds in B. polystachyon leaves, including gallic acid, caffeic acid, vanillic acid, p-coumaric acid, ellagic acid, rosmarinic acid, and trans-cinnamic acid. These compounds were found in different forms, such as free, esterified, and glycosylated. Mercury (II)-exposed plants exhibited elevated levels of vanillic acid (1959.1 ± 3.66 µg/g DW), ellagic acid (213.55 ± 2.11 µg/g DW), and rosmarinic acid (187.72 ± 1.22 µg/g DW). Conversely, lead (II)-exposed plants accumulated higher levels of caffeic acid (42.53±0.61 µg/g DW) and p-coumaric acid (8.04 ± 0.31 µg/g DW). Trans-cinnamic acid was the predominant phenolic compound in control plants, with a concentration of 207.74 ± 1.45 µg/g DW. These results suggest that sublethal doses of heavy metals can act as abiotic elicitors, enhancing the production of phenolic compounds in B. polystachyon. The present work has the potential to open up new commercial opportunities in the pharmaceutical industry.

17.
J R Coll Physicians Edinb ; 53(1): 23-26, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36680356

RESUMEN

Acanthamoeba is a rare cause of granulomatous amoebic encephalitis (GAE) associated with high mortality. There have been few case reports of Acanthamoeba meningoencephalitis worldwide. Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory condition caused by abnormally active macrophages and cytotoxic T lymphocytes; its secondary form is due to infections or malignancies. However, HLH is rather an unknown complication of GAE. We describe an unusual and previously unreported case of Acanthamoeba meningoencephalitis in a young immunocompetent female culminating in secondary HLH.


Asunto(s)
Infecciones Protozoarias del Sistema Nervioso Central , Linfohistiocitosis Hemofagocítica , Humanos , Femenino , Linfohistiocitosis Hemofagocítica/complicaciones , Linfohistiocitosis Hemofagocítica/diagnóstico , Infecciones Protozoarias del Sistema Nervioso Central/complicaciones , Infecciones Protozoarias del Sistema Nervioso Central/diagnóstico , Granuloma/complicaciones
18.
Opt Lett ; 37(10): 1733-5, 2012 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-22627553

RESUMEN

We show that a high degree of steady-state entanglement between two spatially separated and initially uncoupled qubits can be achieved via interaction with a quantized squeezed field in a cavity. The cavity field induces two-photon coherence, which is crucial in creating entanglement between the qubits. Optimum entanglement is obtained when the less dissipative qubit is incoherently pumped while the other dissipates the excitation. Given the current state-of-the-art in cavity quantum electrodynamics and squeezed light sources, our scheme presents an effective way for light-to-matter entanglement transfer.

19.
Phys Rev Lett ; 109(26): 262502, 2012 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-23368553

RESUMEN

The impact of coherent light propagation on the excitation and fluorescence of thorium nuclei in a crystal lattice environment is investigated theoretically. We find that in the forward direction, the fluorescence signal exhibits characteristic intensity modulations dominated by a sped-up initial decay signal that is orders of magnitude faster. This feature can be exploited for the optical determination of the isomeric transition energy. In order to obtain a unmistakable signature of the isomeric nuclear fluorescence, we put forward a novel scheme for the direct measurement of the transition energy via electromagnetically modified nuclear forward scattering involving two fields that couple to three nuclear states.

20.
ACS Appl Mater Interfaces ; 14(38): 43666-43680, 2022 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-36107717

RESUMEN

This paper implements molecular dynamics (MD) simulation using reactive force field (ReaxFF) to evaluate the atomistic origin of the interfacial behavior in the overmolded hybrid unidirectional continuous carbon fiber low-melt PAEK (CFR-LMPAEK)-short carbon fiber reinforced PEEK (SFR-PEEK) polymer composites. From the MD simulation, it was observed that the interfacial properties improve with increasing maximum processing temperature and injection pressure although such an improving trajectory gets saturated beyond specific limits. The interfacial strength and fracture response of the hybrid polymer system at the interface are also evaluated. The mechanical responses obtained from MD simulation are used as adhesive properties in the macroscale finite element analysis (FEA)-based single lap joint (SLJ) model where the interfacial behavior between the adherends (CFR-LMPAEK and SFR-PEEK) is implemented using cohesive zone model (CZM). The simulated FE results show a good correlation with the SLJ experimental data. Thus, by linking the interfacial properties at the molecular scale to the performance of the interfacial bond at the macroscale, the comprehensive approach presented here opens up various efficient avenues toward atomistically engineered performance tuning in hybrid overmolded fiber-reinforced polymer composites to meet desired large-scale performance needs.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA