Chemical vapor deposition of hexagonal boron nitride on germanium from borazine.

The growth of hexagonal boron nitride (hBN) directly onto semiconducting substrates, like Ge and Ge on Si, promises to advance the integration of hBN into microelectronics. However, a detailed understanding of the growth and characteristics of hBN islands and monolayers on these substrates is lacking. Here, we present the growth of hBN on Ge and Ge epilayers on Si high-vacuum chemical vapor deposition from borazine and study the effects of Ge sublimation, surface orientation, and vicinality on the shape and alignment of hBN islands.

Cold Seeded Epitaxy and Flexomagnetism in GdAuGe Membranes Exfoliated From Graphene/Ge(111).

Remote and van der Waals epitaxy are promising approaches for synthesizing single crystalline membranes for flexible electronics and discovery of new properties via extreme strain; however, a fundamental challenge is that most materials do not wet the graphene surface. We develop a cold seed approach for synthesizing smooth intermetallic films on graphene that can be exfoliated to form few nanometer thick single crystalline membranes. Our seeded GdAuGe films have narrow X-ray rocking curve widths of 9-24 arc seconds, which is 2 orders of magnitude lower than their counterparts grown by typical high temperature methods, and have atomically sharp interfaces observed by transmission electron microscopy.

Nucleation Selectivity and Lateral Coalescence of GaAs over Graphene on Ge(111).

We use epitaxial lateral overgrowth (ELO) to produce semimetallic graphene nanostructures embedded in a semiconducting GaAs matrix for potential applications in plasmonics, THz generation and detection, and tunnel junctions in multijunction solar cells. We show that (1) the combination of low sticking coefficient and fast surface diffusion on graphene enhances nucleation selectivity at exposed regions of the substrate and (2) high growth temperatures favor efficient lateral overgrowth, coalescence, and planarization of epitaxial GaAs films over the graphene nanostructures. Our work provides a more complete understanding of ELO using graphene masks, as opposed to more conventional dielectric masks, and enables new types of metal/semiconductor nanocomposites.

Controlling the Balance between Remote, Pinhole, and van der Waals Epitaxy of Heusler Films on Graphene/Sapphire.

Remote epitaxy is promising for the synthesis of lattice-mismatched materials, exfoliation of membranes, and reuse of expensive substrates. However, clear experimental evidence of a remote mechanism remains elusive. Alternative mechanisms such as pinhole-seeded epitaxy or van der Waals epitaxy can often explain the resulting films.

Improved erythema and decreased blister formation in dominant dystrophic epidermolysis bullosa following treatment with pulsed dye laser.

Dominant dystrophic epidermolysis bullosa (DDEB), an inherited disorder due to type VII collagen mutations, is characterized by blisters and erosions that heal with scarring, atrophy, and milia. There is no established role for laser in the management of patients with DDEB. Pulsed dye laser (PDL) is most often used to target vascular skin lesions.

Quantifying Mn Diffusion through Transferred versus Directly Grown Graphene Barriers.

We quantify the mechanisms for manganese (Mn) diffusion through graphene in Mn/graphene/Ge (001) and Mn/graphene/GaAs (001) heterostructures for samples prepared by graphene layer transfer versus graphene growth directly on the semiconductor substrate. These heterostructures are important for applications in spintronics; however, challenges in synthesizing graphene directly on technologically important substrates such as GaAs necessitate layer transfer and annealing steps, which introduce defects into the graphene. photoemission spectroscopy measurements reveal that Mn diffusion through graphene grown directly on a Ge (001) substrate is 1000 times lower than Mn diffusion into samples without graphene ( ∼ 4 × 10 cm/s, ∼ 5 × 10 cm/s at 500 °C).

Sex-based differences in the anatomic distribution of cutaneous squamous cell carcinoma.

Background: Cutaneous squamous cell carcinoma (cSCC) is the second most common malignancy in the United States, and its incidence is increasing. Ultraviolet radiation is the main environmental risk factor for cSCCs; thus, they tend to arise on sun-exposed skin. Most publications cite the head and neck as the predominant location for cSCCs, but these papers do not account for the differential anatomic predication of cSCCs by sex.

Perioperative Serum 25-Hydroxyvitamin D Levels as a Predictor of Postoperative Opioid Use and Opioid Use Disorder: a Cohort Study.

Importance: Vitamin D deficiency is associated with chronic pain syndromes and higher opioid use among cancer patients, but its association with opioid use among opioid-naïve subjects following a major surgical procedure with acute pain has not been explored.

Objective: To determine the association between serum 25-hydroxyvitamin D (25(OH)D) levels, opioid use, and opioid use disorder.

Methods: We identified commercially insured subjects aged 18-64 years with available perioperative serum 25-hydroxyvitamin D (25D) levels who underwent one of nine major surgical procedures in 2000-2014.

Spiking neurons from tunable Gaussian heterojunction transistors.

Spiking neural networks exploit spatiotemporal processing, spiking sparsity, and high interneuron bandwidth to maximize the energy efficiency of neuromorphic computing. While conventional silicon-based technology can be used in this context, the resulting neuron-synapse circuits require multiple transistors and complicated layouts that limit integration density. Here, we demonstrate unprecedented electrostatic control of dual-gated Gaussian heterojunction transistors for simplified spiking neuron implementation.

A pediatric approach to management of skin growths in basal cell nevus syndrome.

Little guidance on management of basal cell nevus syndrome in children exists. We report a case series of four patients diagnosed with BCNS in early childhood, in whom several highly suspicious lesions were biopsied, but several smaller and questionably concerning lesions were treated with therapies that are more tolerable for children, including topical imiquimod, 5-fluorouracil, cryotherapy, or touch electrodessication following topical anesthetic cream. These therapies were well tolerated, and all residual or persistent lesions were subsequently biopsied and found to be benign.

Case Volume-to-Outcome Relationship in Minimally Invasive Esophagogastrectomy.

Background: Outcomes after open esophagogastrectomy (OE) have been shown to depend on institution case volume. We aim to determine whether a similar relationship exists for minimally invasive esophagogastrectomy (MIE).

Methods: Patients who had OE or MIE (excluding robotic procedures) between 2010 and 2013 in the National Cancer Database were included.

Comparative effectiveness of treatment of actinic keratosis with topical fluorouracil and imiquimod in the prevention of keratinocyte carcinoma: A cohort study.

Background: The effectiveness of 5-fluorouracil compared with that of imiquimod for preventing keratinocyte carcinoma is unknown.

Objective: To compare the effectiveness of 5-fluorouracil and that of imiquimod in preventing keratinocyte carcinoma in a real-world practice setting.

Methods: We identified 5700 subjects who filled prescriptions for 5-fluorouracil or imiquimod for treatment of actinic keratosis in 2007.

Characteristics of cardiothoracic surgeons practicing at the top-ranked US institutions.

Background: We aimed to determine which factors distinguish cardiothoracic (CT) surgeons practicing at the top-ranked US institutions from their peers.

Methods: Using online resources, we collected demographics, training information and academic metrics of 694 cardiac (n=489; 70%) and thoracic (n=205; 30%) surgeons practicing at 57 preeminent US institutions, including those with the highest US News & World Report ranking ("top CT centers").

Results: Two hundred and ninety-nine (43.

HLA-DM mediates peptide exchange by interacting transiently and repeatedly with HLA-DR1.

The peptide editor HLA-DM (DM) catalyzes the exchange of peptides bound to MHC class II molecules within antigen presenting cells by generating a "peptide-receptive" MHC class II conformation (MHC(receptive)) to which peptides readily bind and rapidly unbind. While recent work has uncovered the determinants of DM recognition and effector functions, the nature of MHC(receptive) and its interaction with DM remains unclear. Here, we show that DM induces but does not stabilize MHC(receptive) in the absence of peptides.

Short peptide sequences mimic HLA-DM functions.

HLA-DM (DM) plays a critical role in Ag presentation to CD4 T cells by catalyzing the exchange of peptides bound to MHC class II molecules. It is known that DM interaction with MHC II involves conformational changes in the MHC II molecule leading to the disturbance of H-bonds formed between the bound peptide and the MHC II groove leading to peptide dissociation. The specific region of the DM molecule that induces this peptide dissociation is not defined.