Consistency in the Distribution of Bethesda System for Reporting Thyroid Cytology Categories Over 9 Years: A Single Institute, Retrospective Study.

BACKGROUND: The Bethesda System for Reporting Thyroid Cytopathology (BSRTC) has evolved since it was first introduced in 2009 to become a worldwide accepted cytologic analysis reference, due to its simplicity and reproducibility. To date, the consistency of BSRTC throughout time has yet to be investigated. METHODS: Retrospective single institution case series with chart review of all patients who underwent fine-needle aspirations for a thyroid nodule in our institution between the years 2010 and 2018 with a documented BSRTC classification. Data collection included demographics, risk factors, sonographic evaluation, nodule size, and final pathology when feasible. The main outcome is the difference in the rates of BSRTC categories benign, atypia of undetermined significance (AUS), follicular neoplasm, suspicious for malignancy, and malignant (BSRTC II-VI, respectively) between the study years. RESULTS: A total of 2830 thyroid nodules were included. BSRTC II-VI distribution was 83.9% (2373), 8.2%, (232), 2.7% (75), 3.3% (93), and 2.0% (57), respectively. There was no significant change in the overall trend of each BSRTC category distribution throughout the study. There was a significant increase in the benign cytology rate (BSRTC II) in 2011 compared to 2015 and 2018 (76.4% compared to 88.7% and 87.6%, respectively. P < .005) alongside a significant decline in the AUS category rate (BSRTC III) between the same years (13.0% compared to 4.8% and 5.5%, respectively. P < .005). CONCLUSION: BSRTC showed consistency throughout the study across all observed categories. An overlap between AUS and benign may exist, possibly due to the heterogenic definition of AUS as reflected in the 2023 BSRTC subclassification for AUS.

Nonlocal supercurrent of quartets in a three-terminal Josephson junction.

A novel nonlocal supercurrent, carried by quartets, each consisting of four electrons, is expected to appear in a voltage-biased three-terminal Josephson junction. This supercurrent results from a nonlocal Andreev bound state (ABS), formed among three superconducting terminals. While in a two-terminal Josephson junction the usual ABS, and thus the dc Josephson current, exists only in equilibrium, the ABS, which gives rise to the quartet supercurrent, persists in the nonlinear regime. In this work, we report such resonance in a highly coherent three-terminal Josephson junction made in an InAs nanowire in proximity to an aluminum superconductor. In addition to nonlocal conductance measurements, cross-correlation measurements of current fluctuations provided a distinctive signature of the quartet supercurrent. Multiple device geometries had been tested, allowing us to rule out competing mechanisms and to establish the underlying microscopic origin of this coherent nondissipative current.

Charge of a quasiparticle in a superconductor.

Nonlinear charge transport in superconductor-insulator-superconductor (SIS) Josephson junctions has a unique signature in the shuttled charge quantum between the two superconductors. In the zero-bias limit Cooper pairs, each with twice the electron charge, carry the Josephson current. An applied bias VSD leads to multiple Andreev reflections (MAR), which in the limit of weak tunneling probability should lead to integer multiples of the electron charge ne traversing the junction, with n integer larger than 2Δ/eVSD and Δ the superconducting order parameter. Exceptionally, just above the gap eVSD ≥ 2Δ, with Andreev reflections suppressed, one would expect the current to be carried by partitioned quasiparticles, each with energy-dependent charge, being a superposition of an electron and a hole. Using shot-noise measurements in an SIS junction induced in an InAs nanowire (with noise proportional to the partitioned charge), we first observed quantization of the partitioned charge q = e*/e = n, with n = 1-4, thus reaffirming the validity of our charge interpretation. Concentrating next on the bias region eVSD ~ 2Δ, we found a reproducible and clear dip in the extracted charge to q ~ 0.6, which, after excluding other possibilities, we attribute to the partitioned quasiparticle charge. Such dip is supported by numerical simulations of our SIS structure.

Robust Epitaxial Al Coating of Reclined InAs Nanowires.

It was recently shown that in situ epitaxial aluminum coating of indium arsenide nanowires is possible and yields superior properties relative to ex-situ evaporation of aluminum ( Nat. Mater. 2015 , 14 , 400 - 406 ). We demonstrate a robust and adaptive epitaxial growth protocol satisfying the need for producing an intimate contact between the aluminum superconductor and the indium arsenide nanowire. We show that the (001) indium arsenide substrate allows successful aluminum side-coating of reclined indium arsenide nanowires that emerge from (111)B microfacets. A robust, induced hard superconducting gap in the obtained indium arsenide/aluminum core/partial shell nanowires is clearly demonstrated. We compare epitaxial side-coating of round and hexagonal cross-section nanowires and find the surface roughness of the round nanowires to induce a more uniform aluminum profile. Consequently, the extended aluminum grains result in increased strain at the interface with the indium arsenide nanowire, which is found to induce dislocations penetrating into round nanowires only. A unique feature of proposed growth protocol is that it supports in situ epitaxial deposition of aluminum on all three arms of indium arsenide nanowire intersections in a single growth step. Such aluminum coated intersections play a key role in engineering topologically superconducting networks required for Majorana based quantum computation schemes.

Crystal structure and transport in merged InAs nanowires MBE grown on (001) InAs.

Molecular beam epitaxy growth of merging InAs nanowire intersections, that is, a first step toward the realization of a network of such nanowires, is reported. While InAs nanowires play already a leading role in the search for Majorana fermions, a network of these nanowires is expected to promote their exchange and allow for further development of this field. The structural properties of merged InAs nanowire intersections have been investigated using scanning and transmission electron microscope imaging. At the heart of the intersection, a sharp change of the crystal structure from wurtzite to perfect zinc blende is observed. The performed low-temperature conductance measurements demonstrate that the intersection does not impose an obstacle to current transport.

Synthesizing a ν=2/3 fractional quantum Hall effect edge state from counter-propagating ν=1 and ν=1/3 states.

Topological edge-reconstruction occurs in hole-conjugate states of the fractional quantum Hall effect. The frequently studied filling factor, ν = 2/3, was originally proposed to harbor two counter-propagating modes: a downstream v = 1 and an upstream v = 1/3. However, charge equilibration between these two modes always led to an observed downstream v = 2/3 charge mode accompanied by an upstream neutral mode. Here, we present an approach to synthetize a v = 2/3 edge mode from its basic counter-propagating charged constituents, allowing a controlled equilibration between the two counter-propagating charge modes. This platform is based on a carefully designed double-quantum-well, which hosts two populated electronic sub-bands (lower and upper), with corresponding filling factors, vl and vu. By separating the 2D plane to two gated intersecting halves, each with different fillings, counter-propagating chiral modes can be formed along the intersection line. Equilibration between these modes can be controlled with the top gates' voltage and the magnetic field.

Robust integer and fractional helical modes in the quantum Hall effect.

Electronic systems harboring one-dimensional helical modes, where spin and momentum are locked, have lately become an important field of its own. When coupled to a conventional superconductor, such systems are expected to manifest topological superconductivity; a unique phase hosting exotic Majorana zero modes. Even more interesting are fractional helical modes, yet to be observed, which open the route for realizing generalized parafermions. Possessing non-abelian exchange statistics, these quasiparticles may serve as building blocks in topological quantum computing. Here, we present a new approach to form protected one-dimensional helical edge modes in the quantum Hall regime. The novel platform is based on a carefully designed double-quantum-well structure in a GaAs based system hosting two electronic sub-bands; each tuned to the quantum Hall effect regime. By electrostatic gating of different areas of the structure, counter-propagating integer, as well as fractional, edge modes with opposite spins are formed. We demonstrate that due to spin-protection, these helical modes remain ballistic for large distances. In addition to the formation of helical modes, this platform can serve as a rich playground for artificial induction of compounded fractional edge modes, and for construction of edge modes based interferometers.

T-plastin is essential for basement membrane assembly and epidermal morphogenesis.

The establishment of epithelial architecture is a complex process involving cross-talk between cells and the basement membrane. Basement membrane assembly requires integrin activity but the role of the associated actomyosin cytoskeleton is poorly understood. Here, we identify the actin-bundling protein T-plastin (Pls3) as a regulator of basement membrane assembly and epidermal morphogenesis. In utero depletion of Pls3 transcripts in mouse embryos caused basement membrane and polarity defects in the epidermis but had little effect on cell adhesion and differentiation. Loss-of-function experiments demonstrated that the apicobasal polarity defects were secondary to the disruption of the basement membrane. However, the basement membrane itself was profoundly sensitive to subtle perturbations in the actin cytoskeleton. We further show that Pls3 localized to the cell cortex, where it was essential for the localization and activation of myosin II. Inhibition of myosin II motor activity disrupted basement membrane organization. Our results provide insights into the regulation of cortical actomyosin and its importance for basement membrane assembly and skin morphogenesis.