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1.
Nano Lett ; 24(12): 3575-3580, 2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38478720

ABSTRACT

Silicon vacancy centers (SiVs) in diamond have emerged as a promising platform for quantum sciences due to their excellent photostability, minimal spectral diffusion, and substantial zero-phonon line emission. However, enhancing their slow nanosecond excited-state lifetime by coupling to optical cavities remains an outstanding challenge, as current demonstrations are limited to ∼10-fold. Here, we couple negatively charged SiVs to sub-diffraction-limited plasmonic cavities and achieve an instrument-limited ≤8 ps lifetime, corresponding to a 135-fold spontaneous emission rate enhancement and a 19-fold photoluminescence enhancement. Nanoparticles are printed on ultrathin diamond membranes on gold films which create arrays of plasmonic nanogap cavities with ultrasmall volumes. SiVs implanted at 5 and 10 nm depths are examined to elucidate surface effects on their lifetime and brightness. The interplay between cavity, implantation depth, and ultrathin diamond membranes provides insights into generating ultrafast, bright SiV emission for next-generation diamond devices.

2.
ACS Nano ; 17(23): 24022-24032, 2023 Dec 12.
Article in English | MEDLINE | ID: mdl-38014847

ABSTRACT

The nonlinear conversion of photons from lower to higher energy is important for a wide range of applications, from quantum communications and optoelectronics to solar energy conversion and medicine. Triplet-triplet annihilation upconversion (TTA UC), which utilizes an absorber/emitter molecular pair, is a promising tool for upconversion applications requiring low intensity light such as photovoltaics, photocatalysis, and bioimaging. Despite demonstrations of efficient TTA UC in solution, practical applications have proven difficult, as thin films retard the necessary energy transfer steps and result in low emission yields. In this work, TTA UC emission from a thin film is greatly enhanced through integration into plasmonic nanogap cavities consisting of a silver mirror, a nanometer-scale polymer spacer containing a TTA molecular pair, and colloidally synthesized silver nanocubes. Mechanistic studies performed by varying the nanocube side length (45-150 nm) to tune the nanogap cavity resonance paired with simulations reveal absorption rate enhancement to be the primary operative mechanism in overall TTA UC emission enhancement. This absorption enhancement decreases the TTA UC threshold intensity by an order of magnitude and allows TTA UC emission to be excited with light up to 120 nm redder than the usable wavelength range for the control samples. Further, combined nanogap cavities composed of two distinct nanocube sizes result in surfaces which simultaneously enhance the absorption rate and emission rate. These dual-size nanogap cavities result in 45-fold TTA UC emission enhancement. In total, these studies present TTA UC emission enhancement, illustrate how the usable portion of the spectrum can be expanded for a given sensitizer-emitter pair, and develop both mechanistic understanding and design rules for TTA UC emission enhancement by plasmonic nanostructures.

3.
Front Endocrinol (Lausanne) ; 12: 692553, 2021.
Article in English | MEDLINE | ID: mdl-34248850

ABSTRACT

Adenomatoid tumor (AT) is an uncommon benign neoplasm of mesothelial origin, usually occurring in the female and male genital tracts. Extragenital localization such as the adrenal gland is extremely rare. Until now, only 39 cases of adrenal AT have been reported in the English literature. Here we report two novel cases of adrenal AT that occurred in male patients aged 30 and 31 years. The tumors were discovered incidentally by computed tomography (CT). Macroscopically, the tumors were unilateral and solid, and the greatest dimension of the tumors was 3.5 and 8.0 cm, respectively. Histologically, the tumors consisted of angiomatoid, cystic, and solid patterns and infiltrated the adrenal cortical or medullary tissue. The tumor cells had low nuclear/cytoplasmic ratio, with no pathological mitosis or nuclear pleomorphism. Thread-like bridging strands and signet-ring-like cells could be seen. Immunohistochemically, the tumor cells were positive for epithelial markers (AE1/AE3, CK7) and mesothelial markers (D2-40, calretinin, and WT-1). The Ki-67 index was approximately 1 and 2%, respectively. The differential diagnosis of adrenal AT includes a variety of benign and malignant tumors. The patients had neither local recurrence nor distant metastasis at 21 and 8 months after removal of the tumor. In the literature review, we comprehensively summarized the clinical, morphological, immunohistochemical, and prognostic features of adrenal AT. Adrenal ATs are morphologically and immunophenotypically identical to those that occur in the genital tracts. Combining the histology with immunohistochemical profiles is very supportive in reaching the diagnosis of this benign tumor, helping to avoid misdiagnosis and overtreatment.


Subject(s)
Adenomatoid Tumor/diagnosis , Adrenal Gland Neoplasms/diagnosis , Adenomatoid Tumor/pathology , Adrenal Gland Neoplasms/pathology , Adult , Humans , Male , Tomography, X-Ray Computed
4.
Sci Adv ; 5(9): eaaw8693, 2019 09.
Article in English | MEDLINE | ID: mdl-31548985

ABSTRACT

We present a study of a graphene-based Josephson junction with dedicated side gates carved from the same sheet of graphene as the junction itself. These side gates are highly efficient and allow us to modulate carrier density along either edge of the junction in a wide range. In particular, in magnetic fields in the 1- to 2-T range, we are able to populate the next Landau level, resulting in Hall plateaus with conductance that differs from the bulk filling factor. When counter-propagating quantum Hall edge states are introduced along either edge, we observe a supercurrent localized along that edge of the junction. Here, we study these supercurrents as a function of magnetic field and carrier density.

5.
J Cancer Res Clin Oncol ; 145(4): 1027-1035, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30810839

ABSTRACT

PURPOSE: Lung cancer prevalence with its high mortality rate is a trending topic globally. Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. The human gene TTN encoding for TITIN protein is known as major mutation gene in many types of tumor including NSCLC. However, it is still controversial that TTN is a cancer-associated candidate considering tumor heterogeneity and complex genetic structure. In-depth researches on correlation between TTN mutation and NSCLC are still limited and discussable. METHODS: Related somatic mutation profiles and attached clinical data were from The Cancer Genome Atlas (TCGA) lung project. Clinical relevance analysis of TTN mutation was evaluated using univariate analysis and a binary logistic regressive model. Survival analysis and screening of independent prognostic factors in mutation types were conducted by Cox proportional hazards models and Kaplan-Meier methods. RESULTS: Available data covering lung adenocarcinoma (n = 517) and lung squamous cell carcinoma (n = 492) were analyzed. TTN genetic mutations exhibited significant association with lung squamous cell carcinoma. Patients with lung squamous cell carcinoma possessed favorable overall survival benefits from TTN mutant type and both favorable overall survival and disease-free survival benefits from TTN/TP53 double mutation. For patients with lung squamous cell carcinoma, about 85% of subjects with TTN mutation harbored missense variations, which was an independent indicator of good prognosis. CONCLUSIONS: Missense mutation of TTN may act as a beneficial role in lung squamous cell carcinoma, but not in lung adenocarcinoma.


Subject(s)
Carcinoma, Squamous Cell/genetics , Connectin/genetics , Lung Neoplasms/genetics , Mutation, Missense , Adenocarcinoma of Lung/genetics , Aged , Anaplastic Lymphoma Kinase/genetics , ErbB Receptors/genetics , Humans , Kaplan-Meier Estimate , Logistic Models , Middle Aged , Prognosis , Proportional Hazards Models , Protein-Tyrosine Kinases/genetics , Proto-Oncogene Proteins/genetics , Proto-Oncogene Proteins c-ret/genetics , Tumor Suppressor Protein p53/genetics
6.
Nano Lett ; 19(2): 1039-1043, 2019 02 13.
Article in English | MEDLINE | ID: mdl-30620606

ABSTRACT

We investigate the electronic properties of ballistic planar Josephson junctions with multiple superconducting terminals. Our devices consist of monolayer graphene encapsulated in boron nitride with molybdenum-rhenium contacts. Resistance measurements yield multiple resonant features, which are attributed to supercurrent flow among adjacent and nonadjacent Josephson junctions. In particular, we find that superconducting and dissipative currents coexist within the same region of graphene. We show that the presence of dissipative currents primarily results in electron heating and estimate the associated temperature rise. We find that the electrons in encapsulated graphene are efficiently cooled through the electron-phonon coupling.

7.
ACS Macro Lett ; 4(11): 1215-1219, 2015 Nov 17.
Article in English | MEDLINE | ID: mdl-35614839

ABSTRACT

Imparting ordered structures into otherwise amorphous hydrogels is expected to endow these popular materials with novel multiple-stimuli responsiveness that promises many applications. The current contribution reports a method to fabricate pure polymeric hydrogels with an inherent chiral internal structure by templating on the chiral nematic liquid crystal phase of a rodlike virus. A method was developed to form macroscopically homogeneous chiral templates by confinement induced self-assembly in the presence of monomers, cross-linkers and initiators. Polymerization induced gelation was performed without perturbing the elegant 3D chiral organization of the rodlike virus bearing double bonds. Furthermore, a suitable method was found to remove the organic virus template while keeping the desired polymeric replica intact, resulting in a pure polymeric hydrogel with a unique internal chiral feature that originates from the 3D chiral ordering of the cylindrical pores left by the virus. Multiple-stimuli responsiveness has been demonstrated and can be quantified by the change of the pitch of the chiral feature. The chiral structure endows the otherwise featureless hydrogel with a unique material property that might be used as a readout signal for sensing and acts as the basis for responsive, biomimetic nanostructured materials.

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