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The directed self-assembly (DSA) of block copolymers (BCPs) can be used to produce nanoscale patterns without the cost and process complexity of state-of-the-art optical lithography. Thus, DSA may be useful in a wide variety of semiconductor applications such as fin field-effect transistors and biosensors. To create technologically useful patterns with aligned BCP domains, conventional DSA mechanisms often rely on topographically complex structures or high-resolution chemical patterns to direct the self-assembly, that are difficult to fabricate. In comparison, a newly discovered mechanism for DSA, termed boundary-directed epitaxy (BDE), utilizes chemical contrast at the boundaries between a substrate and relatively wide chemical stripe. Here, we demonstrate the use of BDE to template the fabrication of sub-10 nm features for the first time. BDE is used in conjunction with selective infiltration to create ultranarrow line-space arrays of alumina. These results demonstrate a proof-of-concept for BDE as a method for ultrahigh-resolution feature formation.

Hexagonal boron nitride (h-BN) is a promising material for next-generation electronics due to its unique optoelectronic and electronic properties. While the synthesis of h-BN on metallic substrates has been studied extensively, h-BN synthesis on CMOS-compatible substrates like Ge has not. Here, we report the growth of h-BN on Ge(001) from borazine via high-vacuum chemical vapor deposition. We find that the sublimation of Ge under high vacuum inhibits h-BN growth. To overcome this challenge, we place two Ge substrates face-to-face and achieve the growth of aligned h-BN islands and monolayer h-BN films.

To evaluate whether preoperative magnetic resonance imaging (MRI) measurements of multiple tendon autograft sources could be used to improve estimates of intraoperative hamstring tendon autograft (HTA) diameter.Patients who underwent anterior cruciate ligament reconstruction with HTA at our institution were identified through electronic health records. Preoperative MRI tendon measurements of the patellar tendon (PT) length, PT width, PT thickness, quadriceps tendon thickness, semitendinosus tendon (ST) cross-sectional area (CSA), and gracilis tendon (GT) CSA were conducted by 2 independent evaluators using digital imaging measurement tools.A total of 53 patients met the inclusion criteria, with a mean HTA diameter of 7.98 ± 0.7 mm. Height greater than 1.63 m, weight greater than 63.4 kg, PT length greater than 4.2 cm, PT thickness greater than 0.33 cm, ST CSA greater than 10.8 mmBy combining PT length and PT thickness measurements with GT CSA measurements in a logit function model, we were able to show improved overall specificity, sensitivity, and accuracy of estimated HTA diameters in our data set when compared with assessments of anthropometric, ST CSA, GT CSA, or combined ST-GT CSA measurements in isolation.Preoperative MRI measurements may be used to screen whether a patient is likely to have an 8-mm graft in the setting of anterior cruciate ligament reconstruction with HTA and thus may help guide graft choice.

Cemented endoprosthetic reconstruction after resection of primary bone sarcomas has been in common use for decades. Although multiple studies have reported the survivorship of primary endoprostheses, implant survivorship after revision surgery is less well established. Given that earlier advances in systemic therapy improved survival of patients with sarcoma, the usage of revision endoprostheses can be expected to increase and, as such, understanding revision implant survivorship will help to inform patient and surgeon expectations. Additionally, as new implants are developed that allow alternative reconstruction options, a normative dataset establishing accurate expectations for revision cemented endoprostheses is a critical benchmark by which to measure progress.(1) What is the implant survivorship free of all-cause revision for primary and revision cemented distal femoral replacements (DFRs) used in the treatment of malignant or benign tumors? (2) What are the most common indications for revision of primary and revision DFRs in an oncology population with mean follow-up of more than 10 years? (3) How does the indication for revision of a primary DFR affect the subsequent risk for and type of revision DFR complication? (4) What patient, tumor, or implant characteristics are associated with improved survivorship free of revision in cemented DFRs used in patients treated initially for primary malignant or benign tumors?This was a retrospective, comparative study using our institution's longitudinally-maintained database of 806 cemented endoprostheses starting in 1980 and assessed through December 31, 2018. In all, 365 DFRs were inserted during this time, but 14% (51 of 365) were placed for nonprimary bone tumors and 1% (5 of 365) were cementless reconstructions, leaving 309 cemented DFRs. Seventy-one percent (218 of 309) were primary implants and 29 percent (91 of 309) were revision implants (used to revise a prior DFR in all patients). During this time period, our strong bias was to use cemented stems and, thus, nearly all of our patients had cemented stems. Six percent (13 of 218) of primary DFRs were implanted more than 2 years before the study end; however, they lacked 2 years of follow-up data and, thus, were considered lost to follow-up, leaving 205 implants in the primary DFR analysis group. Only the first revision after primary DFR revision surgery was included in the revision cohort analysis. Thirty-two percent (29 of 91) of revision DFRs were second or more revision patients and were excluded, leaving 62 implants in the revision analysis group. Most patients in both groups were men (57% [117 of 205] for primary and 71% [44 of 62] for revision) who had been diagnosed with osteosarcoma (75% [153 of 205] and 73% [45 of 62] for primary and revision, respectively). The primary cohort had mean age of 26 ± 16 years with a mean follow-up of 136 ± 122 months, and the revision cohort had mean age of 31 ± 13 years (p = 0.02) with 141 ± 101 months of follow-up. Study endpoints included all-cause implant revision and cause-specific revision for soft tissue complications, aseptic loosening, structural complications (defined as periprosthetic or implant fracture), infection, or tumor progression. Planned surgery for implant lengthening procedures was excluded. Implant survivorship free from all-cause revision was calculated using a competing risk (cumulative incidence) estimator with death as a competing risk. A log-rank test using chi-square analysis was used to evaluate the differences in implant survivorship between primary DFRs and first revisions. The cause-specific incidences of implant revision were tabulated for primary and revision DFRs. Cox regression analysis investigated the odds of subsequent all-cause revision surgery for revision cemented DFRs based on the primary implant complication. A binary logistic regression analysis using age, gender, indication for revision, tumor type, infection, perioperative chemotherapy, and radiation was performed to identify factors associated with a second DFR reoperation. Relative effect sizes are reported as ORs.The revision DFR cohort had a shorter mean survival to all-cause revision than the primary cohort (mean 10 years [95% CI 7 to 12] versus 18 years [95% CI 15 to 20]; p0.001). The most common complications necessitating revision for revision implants were periprosthetic or implant fracture in 37% (23 of 62) and aseptic loosening in 15% (9 of 62), and the type of primary implant complication was not associated with risk of subsequent all-cause revision surgery for revision implants. Stem diameter less than 15 mm was associated with repeat all-cause revision in cemented revision DFRs after controlling for resection length, stem length, implant fabrication (custom or modular), and presence of a porous collar (OR 4 [95% CI 1 to 17]; p = 0.03). No other parameters that we explored, including patient age, gender, chemoradiation history, or primary tumor diagnosis, were associated with repeat revision surgery.Understanding modifiable factors that can improve revision DFR survival is critical to achieving long-term limb salvage for patients with tumors around the knee. Our data suggest that utilizing implants with the largest possible stems-or at a minimum increasing the stem size over the primary implant-is important to revision cemented DFR survivorship and is an important part of our revision practice. Improving revision implants' resistance to aseptic loosening through designs that resist torsion (a common mode of cemented fixation failure)-such as with the use of custom cross-pin fabrication-may be one method to improve survivorship. Another will be improved implant metallurgy that is resistant to fatigue fracture. Next steps may include understanding the optimal ratio of femoral diaphyseal width to implant diameter in patients where anatomic constraints preclude the insertion of cemented stems 15 mm or more in diameter.Level IV, therapeutic study.

Variation in floral characteristics and growth habits within the native range of the North American wildflower Ratibida columnifera (Nutt.) Wooton & Standl. suggests potential for breeding and selection efforts to develop improved cultivars for commercial and residential landscapes. Experiments in seed propagation were performed to enable perpetuation of unique germplasms. Overnight hydration, storage condition variations, stratification and scarification, and seed maturation effects were assessed to determine impacts on viability and percent germination. Overnight hydration had no impact on percent germination. Germplasm had a significant effect on germination for all remaining experiments. Seed maintained viability at the same rate through 18 months, when slight reductions were noted. Cold storage at 3 °C had no effect on viability or percent germination of dry seed compared with storage at 23 °C. All three germplasms exhibited increased percent germination with some stratification period, and declined significantly in percent germination with all acid scarification treatments. Experiments indicated that most germplasms benefit from between 30 to 60 days of cold, moist stratification. There was a significant interaction effect among germplasms, location on the inflorescences, and maturity stages for R. columnifera. Data suggest that seed should be harvested as close as possible to when natural dispersal would occur for optimum germination. The degree of improvement in viability and percent germination associated with harvesting at various developmental stages, seed pretreatments, and storage conditions suggests that to achieve germination success, pretreatments should be used for propagation of seed from mature inflorescences and that variation can be expected within different genotypes of this species.

Variation in floral characteristics and growth habits within the native range of the North American wildflower Ratibida columnifera (Nutt.) Wooton & Standl. suggest potential for breeding and selection efforts to develop improved cultivars for commercial and residential landscapes. Toward that end, experiments in vegetative propagation were performed to enable perpetuation of unique germplasm. Stem development stage, applications of auxin, genotypic variation, and the effects of bottom heat applications were assessed to determine impacts on rooting percentages and adventitious root system quality measures. Younger apical stem sections rooted more readily and produced better quality root systems than more lignified basal stem cuttings. Optimal rooting percentages and rooted cutting quality ranged from 0.10% to 0.30% IBA (indole-3-butyric acid) quick dips, with 0.30% being optimal for most genotypes. Application of 26 °C bottom heat improved rooting ability in both cool and warm seasons compared with ambient and bottom heat of 32 °C. Bottom heat of 32 °C improved most rooting measures over ambient during the cool season, but not during the warm season. The degree of improvement in adventitious rooting associated with various developmental stage, auxin quick dips, and bottom heating varied among accessions of R. columnifera, suggesting that adventitious rooting characteristics should be evaluated as a selection criterion for cultivar development within this species.

Context.— Pediatric soft tissue tumors are one of the areas of pediatric pathology that frequently generate consult requests. Evolving classification systems, ancillary testing methods, new treatment options, research enrollment opportunities, and tissue archival processes create additional complexity in handling these unique specimens. Pathologists are at the heart of this critical decision-making, balancing responsibilities to consider expediency, accessibility, and cost-effectiveness of ancillary testing during pathologic examination and reporting. Objective.— To provide a practical approach to handling pediatric soft tissue tumor specimens, including volume considerations, immunohistochemical staining panel recommendations, genetic and molecular testing approaches, and other processes that impact the quality and efficiency of tumor tissue triage. Data Sources.— The World Health Organization Classification of Soft Tissue and Bone Tumors, 5th edition, other recent literature investigating tissue handling, and the collective clinical experience of the group are used in this manuscript. Conclusions.— Pediatric soft tissue tumors can be difficult to diagnose, and evaluation can be improved by adopting a thoughtful, algorithmic approach to maximize available tissue and minimize time to diagnosis.

Online misogyny has become a fixture in female politicians’ lives. Backlash theory suggests that it may represent a threat response prompted by female politicians’ counterstereotypical, power-seeking behaviors. We investigated this hypothesis by analyzing Twitter references to Hillary Clinton before, during, and after her presidential campaign. We collected a corpus of over 9 million tweets from 2014 to 2018 that referred to Hillary Clinton, and employed an interrupted time series analysis on the relative frequency of misogynistic language within the corpus. Prior to 2015, the level of misogyny associated with Clinton decreased over time, but this trend reversed when she announced her presidential campaign. During the campaign, misogyny steadily increased and only plateaued after the election, when the threat of her electoral success had subsided. These findings are consistent with the notion that online misogyny towards female political nominees is a form of backlash prompted by their ambition for power in the political arena.

Conjoint analysis can be used to simultaneously investigate consumer preferences on multiple attributes and levels. Our objective was to gain insight regarding consumer preferences for attributes and levels attributed to Ratibida columnifera, a wildflower of potential commercial interest. A ratings-based conjoint analysis using petal color (bicolor, marble, red, yellow), petal shape (circular, oval, notched, lobed), petal number (less than 10, more than 10), and price ($10.00, $15.00, $20.00) was conducted to elucidate part-worth utility from data from 1000 subjects recruited using Amazon Mechanical Turk (MTurk), a crowdsourcing marketplace. Subjects were then clustered according to their conjoint utility scores. In addition to the conjoint analysis, a principal component analysis was performed based on native plant knowledge of the respondent. Conjoint results revealed that petal color was the most important attribute in decision making, followed by price, petal shape, and petal number. Utility values revealed preference for bicolor petals, followed by red, yellow, and marbled color petals. Preference for price went from least expensive to most expensive. Circular petals were favored over oval, notched, and lobed. Subjects also preferred to have 10 petals or more, vs. less than 10 petals. Cluster analysis yielded three consumer segments, which differed in their utility values. These clusters differed in both demographics and R. columnifera preferences. Overall, consumers preferred R. columnifera with partial (bicolor) or complete red coloration over other options, lower prices, more petals, and entire circular or oval petals.

Controlling the deposition of polymer-wrapped single-walled carbon nanotubes (s-CNTs) onto functionalized substrates can enable the fabrication of s-CNT arrays for semiconductor devices. In this work, we utilize classical atomistic molecular dynamics (MD) simulations to show that a simple descriptor of solvent structure near silica substrates functionalized by a wide variety of self-assembled monolayers (SAMs) can predict trends in the deposition of s-CNTs from toluene. Free energy calculations and experiments indicate that those SAMs that lead to maximum disruption of solvent structure promote deposition to the greatest extent. These findings are consistent with deposition being driven by solvent-mediated interactions that arise from SAM-solvent interactions, rather than direct s-CNT-SAM interactions, and will permit the rapid computational exploration of potential substrate designs for controlling s-CNT deposition and alignment.

The epitaxial growth of functional oxides using a substrate with a graphene layer is a highly desirable method for improving structural quality and obtaining freestanding epitaxial nanomembranes for scientific study, applications, and economical reuse of substrates. However, the aggressive oxidizing conditions typically used in growing epitaxial oxides can damage graphene. Here, we demonstrate the successful use of hybrid molecular beam epitaxy for SrTiO

The epitaxial growth of functional oxides using a substrate with a graphene layer is a highly desirable method for improving structural quality and obtaining freestanding epitaxial nanomembranes for scientific study, applications, and economical reuse of substrates. However, the aggressive oxidizing conditions typically used in growing epitaxial oxides can damage graphene. Here, we demonstrate the successful use of hybrid molecular beam epitaxy for SrTiO 3 growth that does not require an independent oxygen source, thus avoiding graphene damage. This approach produces epitaxial films with self-regulating cation stoichiometry. Furthermore, the film (46-nm-thick SrTiO 3 ) can be exfoliated and transferred to foreign substrates. These results open the door to future studies of previously unattainable freestanding oxide nanomembranes grown in an adsorption-controlled manner by hybrid molecular beam epitaxy. This approach has potentially important implications for the commercial application of perovskite oxides in flexible electronics and as a dielectric in van der Waals thin-film electronics.

Cellulose nanocrystals (CNCs) are a naturally abundant nanomaterial derived from cellulose which exhibit many exciting mechanical, chemical, and rheological properties, making CNCs attractive for use in coatings. Furthermore, the alignment of CNCs is important to exploit their anisotropic mechanical and piezoelectric properties. Here, we demonstrate and study the fabrication of submonolayer to 25 nm thick films of CNCs via solution-based shear alignment. CNC solution is forced through a sub-millimeter tall channel at high volumetric flow rates generating shear. The half-width at half-maximum of the spread in CNC alignment significantly improves from 78 to 17° by increasing the shear rate from 19 to 19,000 s

Background Electronic cigarettes are a harm reduction strategy for individuals who smoke cigarettes who cannot or do not want to quit using FDA-approved cessation methods. Identifying perceived facilitators and barriers to switching among people who smoke cigarettes is critical to optimizing health impact. This is particularly important for the most dominant e-cigarette device, nicotine salt pod electronic cigarettes. We investigate the experience using pod electronic cigarettes among African American and Latinx individuals who smoke, the two largest racial/ethnic minority groups who experience significant health disparities. Methods From July 2018 to May 2019, adults who smoked cigarettes, age 21 + (N = 114; M age = 44.6, 59.6% male, 52.6% African American from Kansas City, 47.4% Latinx from San Diego) received JUUL-brand electronic cigarettes (referred to hereafter as JUUL) for 6 weeks and answered interview questions at week six. We inquired what they liked and disliked about using JUUL, what helped with switching and made switching difficult, future intentions for continued JUUL use, and how JUUL compared to past smoking reduction methods. Responses were coded into themes by independent raters. Theme frequencies were analyzed separately by race/ethnicity and week 6 use trajectory (exclusive JUUL use, dual JUUL and cigarette use, exclusive cigarette use). Results Clean/smell was the aspect of using JUUL most commonly liked (23%), followed by convenience (19%). Coughing/harshness was a more common barrier to switching for African American (44%) than Latinx (9%), and for continuing cigarette use (56%) than for those who exclusively switched or dually used JUUL and combustible cigarettes (15–21%). Most (78% African American; 90% Latinx) reported that the benefits of using JUUL outweighed barriers, and this varied by JUUL use trajectory: 94% exclusive switch, 86% dual use, and 42% continued cigarette use. The majority said they would continue using JUUL to replace cigarettes (83% African American; 94% Latinx) and that JUUL worked better than other methods to reduce cigarettes (72%). Conclusion African American and Latinx individuals who smoked experience using pod electronic cigarettes was generally positive. Understanding facilitators and impediments to switching to electronic cigarettes among racial/ethnic minority people who smoke can inform harm reduction interventions and reduce tobacco-related health disparities. Trial Registration ClinicalTrials.gov Identifier: NCT03511001 posted April 27, 2018.

Exciton-polaritons are hybrid states formed when molecular excitons are strongly coupled to photons trapped in an optical cavity. These systems exhibit many interesting, but not fully understood, phenomena. Here, we utilize ultrafast two-dimensional white-light spectroscopy to study donor-acceptor microcavities made from two different layers of semiconducting carbon nanotubes. We observe the delayed growth of a cross peak between the upper- and lower-polariton bands that is oftentimes obscured by Rabi contraction. We simulate the spectra and use Redfield theory to learn that energy cascades down a manifold of new electronic states created by intermolecular coupling and the two distinct bandgaps of the donor and acceptor. Energy most effectively enters the manifold when light-matter coupling is commensurate with the energy distribution of the manifold, contributing to long-range energy transfer. Our results broaden the understanding of energy transfer dynamics in exciton-polariton systems and provide evidence that long-range energy transfer benefits from moderately-coupled cavities.

Remote epitaxy on monolayer graphene is promising for synthesis of highly lattice mismatched materials, exfoliation of free-standing membranes, and re-use of expensive substrates. However, clear experimental evidence of a remote mechanism remains elusive. In many cases, due to contaminants at the transferred graphene/substrate interface, alternative mechanisms such as pinhole-seeded lateral epitaxy or van der Waals epitaxy can explain the resulting exfoliatable single-crystalline films. Here, we find that growth of the Heusler compound GdPtSb on clean graphene on sapphire substrates produces a 30 degree rotated epitaxial superstructure that cannot be explained by pinhole or van der Waals epitaxy. With decreasing growth temperature the volume fraction of this 30 degree domain increases compared to the direct epitaxial 0 degree domain, which we attribute to slower surface diffusion at low temperature that favors remote epitaxy, compared to faster surface diffusion at high temperature that favors pinhole epitaxy. We further show that careful graphene/substrate annealing ($T\sim 700 ^\circ C$) and consideration of the film/substrate vs film/graphene lattice mismatch are required to obtain epitaxy to the underlying substrate for a variety of other Heusler films, including LaPtSb and GdAuGe. The 30 degree rotated superstructure provides a possible experimental fingerprint of remote epitaxy since it is inconsistent with the leading alternative mechanisms.

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 anneal steps, which introduce defects into the graphene. \textit{In-situ} 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 ($D_{gr,direct} \sim 4\times10^{-18}$cm$^2$/s, $D_{no-gr} \sim 5 \times 10^{-15}$ cm$^2$/s at 500$^\circ$C). Transferred graphene on Ge suppresses the Mn in Ge diffusion by a factor of 10 compared to no graphene ($D_{gr,transfer} \sim 4\times10^{-16}cm^2/s$). For both transferred and directly-grown graphene, the low activation energy ($E_a \sim 0.1-0.5$ eV) suggests that Mn diffusion through graphene occurs primarily at graphene defects. This is further confirmed as the diffusivity prefactor, $D_0$, scales with the defect density of the graphene sheet. Similar diffusion barrier performance is found on GaAs substrates; however, it is not currently possible to grow graphene directly on GaAs. Our results highlight the importance of developing graphene growth directly on functional substrates, to avoid the damage induced by layer transfer and annealing.

Semiconducting single-walled carbon nanotubes (SWCNTs) are ideal materials for studying strong light–matter coupling and related polaritonic phenomena at room temperature. SWCNTs possess strong, re...

Carbon nanotubes (CNTs) are ideal candidates for beyond-silicon nano-electronics because of their high mobility and low-cost processing. Recently, assembled massively aligned CNTs have emerged as an important platform for semiconductor electronics. However, realizing sophisticated complementary nano-electronics has been challenging due to the p-type nature of carbon nanotubes in air. Fabrication of n-type behavior field effect transistors (FETs) based on assembled aligned CNT arrays is needed for advanced CNT electronics. Here in this paper, we report a scalable process to make n-type behavior FETs based on assembled aligned CNT arrays. Air-stable and high-performance n-type behavior CNT FETs are achieved with high yield by combining the atomic layer deposition dielectric and metal contact engineering. We also systematically studied the contribution of metal contacts and atomic layer deposition passivation in determining the transistor polarity. Based on these experimental results, we report the successful demonstration of complementary metal-oxide-semiconductor inverters with good performance, which paves the way for realizing the promising future of carbon nanotube nano-electronics.

In solid malignancies, including head and neck squamous cell carcinoma (HNSCC), the immunosuppressive molecule adenosine, which accumulates in the tumor, suppresses cytotoxic CD8+ T cell functions including chemotaxis and tumor infiltration. Adenosine functions through binding to the adenosine A2A receptor (A2AR) present on T cells. In order to increase T cell migration into the tumor, the negative effect of adenosine must be abrogated. Systemic drug treatments targeting A2AR are available; however, they could lead to negative toxicities due to the broad expression of this receptor. Herein, we developed a lipid nanoparticle (NP)-based targeted delivery approach to knock down A2AR in T cells in order to increase their chemotaxis in the presence of adenosine. By using flow cytometry, immunofluorescence, qRT-PCR, and 3D-chemotaxis, we demonstrated that CD45RO-labeled nanoparticles delivering ADORA2A gene-silencing-RNAs decreased ADORA2A mRNA expression and rescued the chemotaxis of HNSCC CD8+ memory T cells. Overall, the data indicate that targeting the adenosine signaling pathway with lipid NPs is successful at suppressing the inhibitory effect of adenosine on the chemotaxis of HNSCC memory T cells, which could ultimately help increase T cell infiltration into the tumor.