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1.
Plast Reconstr Surg Glob Open ; 11(5): e5033, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37255762

RESUMO

Penile inversion vaginoplasty is the most common gender-affirming genital surgery performed around the world. Although individual centers have published their experiences, expert consensus is generally lacking. Methods: Semistructured interviews were performed with 17 experienced gender surgeons representing a diverse mix of specialties, experience, and countries regarding their patient selection, preoperative management, vaginoplasty techniques, complication management, and postoperative protocols. Results: There is significant consistency in practices across some aspects of vaginoplasty. However, key areas of clinical heterogeneity are also present and include use of extragenital tissue for vaginal canal/apex creation, creation of the clitoral hood and inner labia minora, elevation of the neoclitoral neurovascular bundle, and perioperative hormone management. Pathway length of stay is highly variable (1-9 days). Lastly, some surgeons are moving toward continuation or partial reduction of estrogen in the perioperative period instead of cessation. Conclusions: With a broad study of surgeon practices, and encompassing most of the high-volume vaginoplasty centers in Europe and North America, we found key areas of practice variation that represent areas of priority for future research to address. Further multi-institutional and prospective studies that incorporate patient-reported outcomes are necessary to further our understanding of these procedures.

2.
Adv Mater Technol ; 8(1)2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-37007916

RESUMO

Studies of electrosensory systems have led to insights into to a number of general issues in biology. However, investigations of these systems have been limited by the inability to precisely control spatial patterns of electrosensory input. In this paper, an electrode array and a system to selectively stimulate spatially restricted regions of an electroreceptor array is presented. The array has 96 channels consisting of chrome/gold electrodes patterned on a flexible parylene-C substrate and encapsulated with another parylene-C layer. The conformability of the electrode array allows for optimal current driving and surface interface conditions. Recordings of neural activity at the first central processing stage in weakly electric mormyrid fish support the potential of this system for high spatial resolution stimulation and mapping of electrosensory systems.

3.
Adv Mater Technol ; 8(19)2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-38559403

RESUMO

MicroLEDs provide unrivaled luminance and operating lifetime, which has led to significant activity using devices for display and non-display applications. The small size and high power density of microLEDs, however, causes increased adverse heating effects which can limit performance. A new generation of electrically insulating high thermal conductivity materials, such as alumina, has been proposed to mitigate these thermal effects when used as a substrate as an alternative to glass. This strategy then could be used as a method of passive heatsinking to improve the overall performance of the microLED. In this work, a newly available material, an 80 micron thick alumina ceramic substrate, is shown to yield a 30 % improvement on average in the maximum current drive over a glass substrate.

4.
Nanoscale ; 13(23): 10365-10384, 2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-33988208

RESUMO

We report nanoscale Eu0.5Ba0.5TiO3, a multiferroic in the bulk and candidate in the search to quantify the electric dipole moment of the electron. Eu0.5Ba0.5TiO3, in the form of nanoparticles and other nanostructures is interesting for nanocomposite integration, biomedical imaging and fundamental research, based upon the prospect of polarizability, f-orbital magnetism and tunable optical/radio luminescence. We developed a [non-hydrolytic]sol-[H2O-activated]gel route, derived from in-house metallic Ba(s)/Eu(s) alkoxide precursors and Ti{(OCH(CH3)2}4. Two distinct nanoscale compounds of Ba:Ti:Eu with the parent perovskite crystal structure were produced, with variable dielectric, magnetic and optical properties, based on altering the oxidizing/reducing conditions. Eu0.5Ba0.5TiO3 prepared under air/O2 atmospheres produced a spherical core-shell nanostructure (30-35 nm), with perovskite Eu0.5Ba0.5TiO3 nanocrystal core-insulating oxide shell layer (∼3 nm), presumed a pre-pyrochlore layer abundant with Eu3+. Fluorescence spectroscopy shows a high intensity 5D0→7F2 transition at 622 nm and strong red fluorescence. The core/shell structure demonstrated excellent capacitive properties: assembly into dielectric thin films gave low conductivity (2133 GΩ mm-1) and an extremely stable, low loss permittivity of εeff∼25 over a wide frequency range (tan δ < 0.01, 100 kHz-2 MHz). Eu0.5Ba0.5TiO3 prepared under H2/argon produced more irregular shaped nanocrystals (20-25) nm, with a thin film permittivity around 4 times greater (εeff 101, tan δ < 0.05, 10 kHz-2 MHz, σ∼59.54 kΩ mm-1). Field-cooled magnetization values of 0.025 emu g-1 for EBTO-Air and 0.84 emu g-1 for EBTO-Argon were observed. X-ray photoelectron spectroscopy analysis reveals a complex interplay of EuII/III/TiIII/IV configurations which contribute to the observed ferroic and fluorescence behavior.

5.
ACS Sens ; 5(6): 1514-1534, 2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32410445

RESUMO

Volatile organic compounds (VOCs) are pervasive in the environment. Since the early 1980s, substantial work has examined the detection of these materials, as they can indicate environmental changes that can affect human health. VOCs and similar compounds present a very specific sensing problem in that they are not reactive and often nonpolar, so it is difficult to find materials that selectively bind or adsorb them. A number of techniques are applied to vapor sensing. High resolution molecular separation approaches such as gas chromatography and mass spectrometry are well-characterized and offer high sensitivity, but are difficult to implement in portable, real-time monitors, whereas approaches such as chemiresistors are promising, but still in development. Gravimetric approaches, in which the mass of an adsorbed vapor is directly measured, have several potential advantages over other techniques but have so far lagged behind other approaches in performance and market penetration. This review aims to offer a comprehensive background on gravimetric sensing including underlying resonators and sensitizers, as well as a picture of applications and commercialization in the field.


Assuntos
Compostos Orgânicos Voláteis , Gases , Humanos
6.
J Am Chem Soc ; 141(28): 10967-10971, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31260283

RESUMO

Atomically precise nanoscale clusters could assemble into crystalline ionic crystals akin to the atomic ionic solids through the strong electrostatic interactions between the constituent clusters. Here we show that, unlike atomic ionic solids, the electrostatic interactions between nanoscale clusters could be frustrated by using large clusters with long and flexible side-chains so that the ionic cluster pairs do not crystallize. As such, we report ionic superatomic materials that can be easily solution-processed into completely amorphous and homogeneous thin-films. These new amorphous superatomic materials show tunable compositions and new properties that are not achievable in crystals, including very high electrical conductivities of up to 300 S per meter, ultra low thermal conductivities of 0.05 W per meter per degree kelvin, and high optical transparency of up to 92%. We also demonstrate thin-film thermoelectrics with unoptimized ZT values of 0.02 based on the superatomic thin-films. Such properties are competitive to state-of-the-art materials and make superatomic materials promising as a new class of electronic and thermoelectric materials for devices.

7.
ACS Nano ; 9(2): 1263-70, 2015 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-25621502

RESUMO

We report a synthetic approach to produce raspberry-like plasmonic nanostructures with unusually strong magnetic resonances, termed raspberry-like metamolecules (raspberry-MMs). The synthesis based on the surfactant-assisted templated seed-growth method allows for the simultaneous one-step synthesis and assembly of well-insulated gold nanoparticles. The aromatic surfactant used for the syntheses forms a thin protective layer around the nanoparticles, preventing them from touching each other and making it possible to pack discrete nanoparticles at close distances in a single cluster. The resulting isotropic gold nanoparticle clusters (i.e., raspberry-MMs) exhibit unusually broad extinction spectra in the visible and near-IR region. Finite-difference time-domain (FDTD) modeling showed that the raspberry-MMs support strong magnetic resonances that contribute significantly to the broadband spectra. The strong magnetic scattering was also verified by far-field scattering measurements, which show that in the near-IR region the magnetic dipole resonance can be even stronger than the electric dipole resonance in these raspberry-MMs. Structural parameters such as the size and the number of gold nanoparticles composing raspberry-MMs can be readily tuned in our synthetic method. A series of syntheses with varying structure parameters, along with FDTD modeling and mode analyses of corresponding model structures, showed that the close packing of a large number of metal nanoparticles in raspberry-MMs is responsible for the unusually strong magnetic resonances observed here.

8.
Artigo em Inglês | MEDLINE | ID: mdl-24483474

RESUMO

Chromonic liquid crystals are formed by molecules that spontaneously assemble into anisotropic structures in water. The ordering unit is therefore a molecular assembly instead of a molecule as in thermotropic liquid crystals. Although it has been known for a long time that certain dyes, drugs, and nucleic acids form chromonic liquid crystals, only recently has enough knowledge been gained on how to control their alignment so that studies of their fundamental liquid crystal properties can be performed. In this article, a simple method for producing planar alignment of the nematic phase in chromonic liquid crystals is described, and this in turn is used to create twisted nematic structures of both achiral and chiral chromonic liquid crystals. The optics of 90-degree twist cells allows the anchoring strength to be measured in achiral systems, which for this alignment technique is quite weak, about 3×10(-7) J/m(2) for both disodium cromoglycate and Sunset Yellow FCF. The addition of a chiral amino acid to the system causes the chiral nematic phase to form, and similar optical measurements in 90-degree twist cells produce a measurement of the intrinsic pitch of the chiral nematic phase. From these measurements, the helical twisting power for L-alanine is found to be (1.1±0.4)×10(-2) µm(-1) wt%(-1) for 15 wt% disodium cromoglycate.

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