Transparent Conductors Printed from Grids of Highly Conductive Silver Nanosheets.

Transparent conductors (TCs) represent key components in many applications from optoelectronic devices to electromagnetic shielding. While commercial applications typically use thin films of indium tin oxide, this material is brittle and increasingly scarce, meaning higher performing and cheaper alternatives are sought after. Solution-processible metals would be ideal owing to their high conductivities and printability. However, due to their opacity to visible light, such films need to be very thin to achieve transparency, thus limiting the minimum resistance achievable. One solution is to print metallic particles in a grid structure, which has the advantages of high tunable transparency and resistance at the cost of uniformity. Here, we report silver nanosheets that have been aerosol jet printed into grids as high-performance transparent conductors. We first investigate the effect of annealing on the silver nanosheets where we observe the onset of junction sintering at 160 °C after which the silver network becomes continuous. We then investigate the effect of line width and thickness on the electrical performance and the effect of varying the aperture dimensions on the optical performance. Using these data, we develop simple models, which allow us to optimize the grid and demonstrate a printed transparent conductor with a transmittance of 91% at a sheet resistance of 4.6 Ω/sq.

Feasibility of Axillary Lymph Node Localization and Excision Using Radar Reflector Localization.

INTRODUCTION: Neoadjuvant chemotherapy (NAC) is commonly used for patients with clinically detected nodal metastases. Sentinel lymph node biopsy (SLNB) after NAC is feasible. Excision of biopsy-proven positive lymph nodes in addition to SLNB, termed targeted axillary dissection (TAD), decreases the false-negative rate of SLNB alone. Positive nodes can be marked with radar reflector-localization (RRL) clips. We report our institutional experience with RRL-guided TAD and demonstrate its safety and feasibility. PATIENTS AND METHODS: We performed an institutional review board-approved retrospective review of consecutive clinically node-positive female patients with breast cancer treated with NAC and RRL-guided TAD between January 2017 and September 2019. Clinicopathologic and treatment data were collected; descriptive statistics are reported. RESULTS: Forty-five patients were analyzed; the median age was 55 years (range, 20-72 years), and the median body mass index was 27.2 kg/m2 (range, 16.5-40.4 kg/m2). All patients received NAC, primary breast surgery, and TAD. All clinically detected nodal metastases were confirmed with percutaneous biopsy and marked with a biopsy clip. RRL clips were implanted a median of 8 days (range, 1-167 days) prior to surgery; all were retrieved without complications. The RRL node was identified as the sentinel lymph node in 36 (80%) patients. Twenty-five patients had positive nodes, of which 24 were identified by RRL node excision, and 1 (4%) patient had a positive node identified by SLNB but not RRL. Over a median follow-up time of 29.6 months, 5 patients recurred (1 local, 4 distant). CONCLUSIONS: RRL-guided TAD after NAC is safe and feasible. This technique allows for adequate assessment of the nodal basin and helps confirm excision of the previously biopsied positive axillary node.

Telomere dysfunction cooperates with epigenetic alterations to impair murine embryonic stem cell fate commitment.

The precise relationship between epigenetic alterations and telomere dysfunction is still an extant question. Previously, we showed that eroded telomeres lead to differentiation instability in murine embryonic stem cells (mESCs) via DNA hypomethylation at pluripotency-factor promoters. Here, we uncovered that telomerase reverse transcriptase null (Tert-/-) mESCs exhibit genome-wide alterations in chromatin accessibility and gene expression during differentiation. These changes were accompanied by an increase of H3K27me3 globally, an altered chromatin landscape at the Pou5f1/Oct4 promoter, and a refractory response to differentiation cues. Inhibition of the Polycomb Repressive Complex 2 (PRC2), an H3K27 tri-methyltransferase, exacerbated the impairment in differentiation and pluripotency gene repression in Tert-/- mESCs but not wild-type mESCs, whereas inhibition of H3K27me3 demethylation led to a partial rescue of the Tert-/- phenotype. These data reveal a new interdependent relationship between H3K27me3 and telomere integrity in stem cell lineage commitment that may have implications in aging and cancer.

Trends in use of bilateral prophylactic mastectomy vs high-risk surveillance in unaffected carriers of inherited breast cancer syndromes in the Inherited Cancer Registry (ICARE).

PURPOSE: Awareness of inherited breast cancer has increased bilateral prophylactic mastectomy (BPM) among unaffected genetic mutation carriers, yet many still choose surveillance. We aimed to identify differences among women electing BPM vs high-risk surveillance. METHODS: Participants from an IRB-approved database recruited from 11/2000 to 01/2017 with a deleterious/pathogenic, variant suspected deleterious, or likely pathogenic mutation in ≥ 1 of 11 genes with increased risk for breast cancer (per 2017 NCCN guidelines) were identified. Participants with breast cancer and males were excluded. Sociodemographic and clinical data were collected. The BPM and high-risk surveillance groups were compared using Wilcoxon, Fisher's Exact, and Pearson's Chi-Square analyses. RESULTS: A total of 304 unaffected genetic mutation carriers were identified; 22 men were excluded. 113/282 (40%) underwent BPM. There was no significant difference in age, race, marital status, high school graduates, family history of breast cancer, breast biopsies, chemoprevention use, or understanding implications of genetic mutation carriage. BPM participants were more likely to have a prior pregnancy (p = 0.0005), college education (p = 0.04), income > $50,000/year (p = 0.01), first-degree relative with breast cancer (p = 0.04), higher total number of relatives with breast cancer (p = 0.01), and rate of risk-reducing salpingo-oophorectomy (p = < 0.0001). The high-risk surveillance group was more likely to have a history of ovarian cancer (p = 0.009) and cancer worry (p = < 0.0001). CONCLUSIONS: BPM is a common but not universal choice among unaffected genetic carriers of inherited breast cancer syndromes. Parity, education, income, ovarian cancer history, first-degree relatives with breast cancer, and cancer worry play significant roles in these decisions.