One-dimensional hexagonal boron nitride conducting channel

Hexagonal boron nitride (hBN) is an insulating two-dimensional (2D) material with a large bandgap. Although known for its interfacing with other 2D materials and structural similarities to graphene, the potential use of hBN in 2D electronics is limited by its insulating nature. Here, we report atomically sharp twin boundaries at AA???/AB stacking boundaries in chemical vapor deposition???synthesized few-layer hBN. We find that the twin boundary is composed of a 6???6??? configuration, showing conducting feature with a zero bandgap. Furthermore, the formation mechanism of the atomically sharp twin boundaries is suggested by an analogy with stacking combinations of AA???/AB based on the observations of extended Klein edges at the layer boundaries of ABstacked hBN. The atomically sharp AA???/AB stacking boundary is promising as an ultimate 1D electron channel embedded in insulating pristine hBN. This study will provide insights into the fabrication of single-hBN electronic devices

Arsenic Inhibits DNA Mismatch Repair by Promoting EGFR Expression and PCNA Phosphorylation

Both genotoxic and non-genotoxic chemicals can act as carcinogens. However, while genotoxic compounds lead directly to mutations that promote unregulated cell growth, the mechanism by which non-genotoxic carcinogens lead to cellular transformation is poorly understood. Using a model non-genotoxic carcinogen, arsenic, we show here that exposure to arsenic inhibits mismatch repair (MMR) in human cells, possibly through its ability to stimulate epidermal growth factor receptor (EGFR)-dependent tyrosine phosphorylation of proliferating cellular nuclear antigen (PCNA). HeLa cells exposed to exogenous arsenic demonstrate a dose- and time-dependent increase in the levels of EGFR and tyrosine 211-phosphorylated PCNA. Cell extracts derived from arsenic-treated HeLa cells are defective in MMR, and unphosphorylated recombinant PCNA restores normal MMR activity to these extracts. These results suggest a model in which arsenic induces expression of EGFR, which in turn phosphorylates PCNA, and phosphorylated PCNA then inhibits MMR, leading to increased susceptibility to carcinogenesis. This study suggests a putative novel mechanism of action for arsenic and other non-genotoxic carcinogens

The susceptibility of Anopheles lesteri to infection with Korean strain of Plasmodium vivax

<p>Abstract</p> <p>Background</p> <p>Following its recent re-emergence, malaria has gained renewed attention as a serious infectious disease in Korea. Three species of the Hyrcanusgroup, <it>Anopheles lesteri, Anopheles sinensis </it>and <it>Anopheles pullus</it>, have long been suspected malaria vectors. However, opinions about their vector ability are controversial. The present study was designed with the aim of determining the susceptibility of these mosquitoes to a Korean isolate of <it>Plasmodium vivax</it>. Also, <it>An. sinensis </it>is primarily suspected to be vector of malaria in Korea, but in Thailand, the same species is described to have less medical importance. Therefore, comparative susceptibility of Thai and Korean strains of <it>An. sinensis </it>with Thai strain of <it>P. vivax </it>may be helpful to understand whether these geographically different strains exhibit differences in their susceptibility or not.</p> <p>Methods</p> <p>The comparative susceptibility of <it>An. lesteri</it>, <it>An. sinensis </it>and <it>An. pullus </it>was studied by feeding laboratory-reared mosquitoes on blood from patients carrying gametocytes from Korea and Thailand.</p> <p>Results</p> <p>In experimental feeding with Korean strain of <it>P. vivax</it>, oocysts developed in <it>An. lesteri</it>, <it>An. sinensis </it>and <it>An. pullus</it>. Salivary gland sporozoites were detected only in <it>An. lesteri </it>and <it>An. sinensis </it>but not in <it>An. pullus</it>. Large differences were found in the number of sporozoites in the salivary glands, with <it>An. lesteri </it>carrying much higher densities, up to 2,105 sporozoites in a single microscope field of 750 × 560 μM, whereas a maximum of 14 sporozoites were found in any individual salivary gland of <it>An. sinensis</it>. Similar results were obtained from a susceptibility test of two different strains of <it>An. sinensis </it>to Thai isolate of <it>P. vivax</it>, and differences in vector susceptibility according to geographical variation were not detected.</p> <p>Conclusion</p> <p>The high sporozoite rate and sporozoite loads of <it>An. lesteri </it>indicate that this species is highly susceptible to infection with <it>P. vivax</it>. <it>Anopheles sinensis </it>appears to have a markedly reduced ability to develop salivary gland infection, whilst in <it>An. pullus</it>, no sporozoites were found in the salivary glands. Provided that the survival rate of <it>An. lesteri </it>is sufficiently high in the field, it would be a highly competent vector of vivax malaria.</p

Developing a multi-center clinical data mart of ACEI and ARB for real-world evidence (RWE)

Background Randomized controlled trials can be expensive and time-consuming, leading to medical researchers utilizing real-world evidence (RWE) based on already-collected data. We aimed to conduct various RWE studies on angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II receptor blocker (ARB), commonly used as first-line therapy for blood pressure, and to develop a multi-center clinical data mart (CDM) of ACEI/ARB for various clinical purposes. Methods Data from electronic medical records of St. Marys Hospital and the Seoul National University Hospital were collected. We obtained blood and urine test results of patients within the 30 days prior to their first prescription of ACEI or ARB, as well as the first date of diagnosis and presence of various chronic and cardiovascular diseases using the International Classification of Diseases-10 classification. One researcher managed data quality and collation for each hospital in order to facilitate patient anonymity. When results were unclear, the responsible investigator for each hospital attempted to resolve ambiguities by direct chart review. Results A total of 102,333 patients who were prescribed ACEI or ARB for the first time were included (21,481 ACEI, 80,551 ARB, and 301 both). Our ACEI/ARB-CDM included short-term studies (within 12 months) to observe changes in various blood or urinary laboratory test values after the initial prescription of ACEI or ARB and long-term studies to confirm the incidence of various diseases. Conclusion We established a CDM of RWE for ACEI/ARB prescription, which included various clinical studies. As we accumulate experience in this process, we expect that the use of RWE research will grow and develop.The research was supported by funding from the Korean Society of Hypertension (2018)

Designing AI Interfaces for Children with Special Needs in Educational Contexts

The IDC research community has a growing interest in designing AI interfaces for children with special educational needs. Nonetheless, little research has explored the research and design issues, rationale, challenges, and opportunities in this field. Therefore, we propose to host a half-day workshop to bring together researchers and practitioners from the Learning & Education, Accessibility, and Intelligent User Interfaces sub-fields to discuss and identify existing design issues, challenges, and collaboration barriers, to establish consensus on the design of a pragmatic framework, as well as explore future innovation and research opportunities. We aim to foster mutual unders

National Trends in Smoking Cessation Medication Prescriptions for Smokers With Chronic Obstructive Pulmonary Disease in the United States, 2007-2012

Objectives Smoking cessation decreases morbidity and mortality due to chronic obstructive pulmonary disease (COPD). Pharmacotherapy for smoking cessation is highly effective. However, the optimal prescription rate of smoking cessation medications among smokers with COPD has not been systemically studied. The purpose of this study was to estimate the national prescription rates of smoking cessation medications among smokers with COPD and to examine any disparities therein. Methods We conducted a retrospective study using National Ambulatory Medical Care Survey data from 2007 to 2012. We estimated the national prescription rate for any smoking cessation medication (varenicline, bupropion, and nicotine replacement therapy) each year. Multiple survey logistic regression was performed to characterize the effects of demographic variables and comorbidities on prescriptions. Results The average prescription rate of any smoking cessation medication over 5 years was 3.64%. The prescription rate declined each year, except for a slight increase in 2012: 9.91% in 2007, 4.47% in 2008, 2.42% in 2009, 1.88% in 2010, 1.46% in 2011, and 3.67% in 2012. Hispanic race and depression were associated with higher prescription rates (odds ratio [OR], 5.15; 95% confidence interval [CI], 1.59 to 16.67 and OR, 2.64; 95% CI, 1.26 to 5.51, respectively). There were no significant differences according to insurance, location of the physician, or other comorbidities. The high OR among Hispanic population and those with depression was driven by the high prescription rate of bupropion. Conclusions The prescription rate of smoking cessation medications among smokers with COPD remained low throughout the study period. Further studies are necessary to identify barriers and to develop strategies to overcome them

Profiling the selectivity of DNA ligases in an array format with mass spectrometry

This article describes a method for the global profiling of the substrate specificities of DNA ligases and illustrates examples using the Taq and T4 DNA ligases. The method combines oligonucleotide arrays, which offer the benefits of high throughput and multiplexed assays, with mass spectrometry to permit label-free assays of ligase activity. Arrays were prepared by immobilizing ternary biotin-tagged DNA substrates to a self-assembled monolayer presenting a layer of streptavidin protein. The array represented complexes having all possible matched and mismatched base pairs at the 3′ side of the nick site and also included a number of deletions and insertions at this site. The arrays were treated with ligases and adenosine triphosphate or analogs of the nucleotide triphosphate and then analyzed by matrix-assisted laser desorption-ionization mass spectrometry to determine the yields for both adenylation of the 5′-probe strand and joining of the two probe strands. The resulting activity profiles reveal the basis for specificity of the ligases and also point to strategies that use ATP analogs to improve specificity. This work introduces a method that can be applied to profile a broad range of enzymes that operate on nucleic acid substrates

Left Paraduodenal Hernia Presenting with Atypical Symptoms

Paraduodenal hernias are a rare congenital malformation, but they are the most common internal hernias. They develop secondary to a failure in midgut rotation, which may lead to small bowel obstruction or other clinical manifestations. The authors recently experienced a case of a left paraduodenal hernia presenting with unusual symptoms of left flank pain and vomiting