Strain-induced rich magnetic phase transitions and enhancement of magnetic stability for O-terminated h-BN nanoribbons

Mono-layered h-BN and its derivatives are very important low-dimensional materials, which have been widely investigated so far. Here, we theoretically study the structural stability and magneto-electronic properties of oxygen (O) terminated zigzag-edged h-BN nanoribbons, especially focusing on strain tuning effects. The O dimerization at the B edge of the ribbon enhances the system stability greatly. A Poisson ratio of 0.2 and bearing a strain more than 20% can be reached. In the absence of strain, the O-terminated ribbon is a magnetic metal. However, the rich magnetic phase transitions among the non-magnetic metal, a spin gapless semiconductor, and a wide-gap half-metal can be realized continuously by applying strain in the ferromagnetic state. Thus, based on such a material feature, we can design a magnetic switch device which can work between the magnetic and non-magnetic states by strain modification. Also shown is that the magnetism stability can be enhanced to the level at room temperature upon strain, and the massless Dirac-fermion behavior for the β-spin state can be clearly detected in the spin gapless semiconductor phase under appropriate strains.

Spin-dependent carrier mobility and its gate-voltage modifying effects for functionalized single walled black phosphorus tubes

Phosphorene and its derivatives so far have attracted substantial research interest due to its promising properties for developing nanoscale electronic devices. Here, we present a theoretical investigation on the functionalized features, such as the improved electronic structure and carrier mobility, for armchair-edged single walled black phosphorus nanotubes (PNTs) with the substitutional doping of low-concentration transition-metal atoms (Ti, Mn, Fe, and Ni). They are predicted to be exceptional magnetic semiconductors (MSCs), such as half-semiconductor or bipolar MSC. Their spin-resolved carrier mobility at room temperature holds doping element- dependence as well as carrier and spin polarity. Particularly, the difference by two orders of magnitude for carrier mobility emerges due to different TM doping. More interestingly, the carrier mobility in armchair PNTs serving as the channel material of a spin field effect transistor is predicted to be modified strongly by a gate voltage. The enhanced carrier mobility and its gate voltage direction-dependent behavior, as well as the more obvious carrier and spin polarity of mobility, can be observed clearly under gate voltage, which further facilitates the separation of different carriers and spin states and also suggests that realistic carrier mobility is gate voltage-dependent in a field effect transistor.

[Correlation between estrogen receptor β and ABCC11 gene single nucleotide polymorphisms and axillary osmidrosis]

OBJECTIVE

To explore the correlation between single nucleotide polymorphisms (SNPs) of hormone receptor gene or other related genes and axillary osmidrosis (AO).
 Methods: Whole blood samples of 219 patients with AO and 159 normal people were collected, and their genomic DNA was extracted. SNPs of 49 selected gene loci were detected and analyzed by using matrix-assisted laser analysis and ionization time of flight mass spectrometry and other related technologies.
 Results: There were significant differences in SNPs at rs1256061 of estrogen receptor β gene and rs17822931, rs16945916 and rs62058521 in ABCC11 gene between the AO patients and normal people (all P<0.01). 81.1% of patients with AO carried G allele at rs1256061, while only 63.2% of normal people carried G allele; 96.3% of patients with AO carried G allele at rs17822931, while only 4.4% of the normal people carried G allele; 28.6% of the patients with armpit odor carried the G allele of rs16945916, while only 0.6% of the normal people carried G allele; 28.0% of patients with AO carried G allele at rs62058521, while only 0.6% of the normal people carried G allele.
 Conclusion: SNPs of rs1256061 at the locus of estrogen receptor gene are correlated with the pathogenesis of AO, while SNPs at multiple loci (rs16945916, rs62058521 and rs17822931) in ABCC11 gene are correlated with the pathogenesis of AO.

Abstract P5-04-17: Local network topology differences between early and late recurrence in ER+ breast cancers

Background: Late recurrence is characteristic of ER+ breast cancers. Despite an apparently effective adjuvant endocrine therapy, many breast cancers recur years after their initial endocrine treatment. Why some tumors recur early (&lt;3 years) and some recur later (&gt;5 years) is poorly understood. If systemic endocrine therapies killed all cells, recurrence would reflect only the appearance of new disease. Thus, we hypothesized that cells that survive and lie dormant may be driven, in part, by altered wiring of their cell death signaling. We, therefore, studied how cell death signaling is differentially wired in primary tumors that will recur early versus those that will recur later.

Method: Genes involved in apoptosis, autophagy, ferroptosis, necrosis, and pyroptosis were identified from KEGG to initiate network feature analysis of gene expression data from public and our first in-house gene expression dataset. Data were collected from ER+ breast cancer pre-endocrine treatment samples with up to 20 years follow-up. Publicly available datasets used were GSE6532, GSE2034, GSE7390, GSE17705, GSE12093, and TCGA. We applied our Knowledge-fused Differential Dependency Network (KDDN) analysis tool to the public datasets; KDDN has provided powerful new insights into signaling in breast and other cancers. Common gene-gene interactions (edges) predicted in at least two different datasets were extracted from all KDDN analyses results. To strengthen the relevance of these features, predicted network edges that represent known protein-protein interactions (PPI) were identified from the STRING database, and these edges were noted in the signaling graphs. Final network graphs were constructed using the common edges from all overlaid networks. We conducted IPA analysis on all nodes in the final network and selected those incorporating network hubs. We took a similar approach to our second in-house dataset, which we used for independent testing. Here, patients were included if their tumor exhibited an initial reduction in volume of at least 40% by four months in response to neo-adjuvant Letrozole. Patients were then classified into two groups during follow-up of up to 3.7 years: i) initial tumor size reduction followed by continued response (expected to recur late); ii) initial reduction followed by tumor regrowth (expected to recur early). KDDN analysis was performed on pretreatment samples from these two groups and a network created annotated with PPI information.

Results: MAPK8 and CYCS (Molecular Mechanisms of Cancer, p=1.58E-52), TNFRSF1A Neuroinflammation Signaling Pathway, p=1.26E-54), RELA, and NFKB1 (Colorectal Cancer Metastasis Signaling, p=7.94E-35), were identified as hubs. Hubs may be critical signaling components driving the differences between tumors that will become dormant and recur late. Connections between SLC25A6 and SQSTM1 (p = 0.008), BIRC2 and GABARAP (p = 0.021) in the early group, and AKT3 and IRS2 (p = 0.014) in the late group, were shared between the two final networks. With longer follow-up time on the second in-house dataset, we will better define the two groups and identify additional common phenotype specific gene-gene interactions.

Citation Format: Clarke R, Dixon M, Jin L, Pearce D, Turnbull A, Selli C, Hu R, Zwart A, Wang Y, Xuan J, Sengupta S, Sims A, Liu MC. Local network topology differences between early and late recurrence in ER+ breast cancers [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-04-17.

Pacemaker-driven Tachycardia Induced by Electrocardiograph Monitoring in the Recovery Room

Monitoring devices are known to induce tachycardia in minute-ventilation rate-responsive pacemakers. This is because some monitoring devices measure the same parameter as do the pacemakers (change in thoracic impedance). Hence, the biological signal to the pacemaker is increased and is misconstrued as increased minute ventilation causing tachycardia which resolves when the monitoring device is removed. Whilst this could occur for all minute-volume rate responsive pacemakers, most reported interactions have been with the Telectronics META series. We present a case of an interaction between a Telectronics Tempo DR pacemaker (St. Jude Medical) and an Agilent Patient Care System (Philips). Failure to recognise the true nature and cause of such tachycardias may lead to mismanagement of the patient, including the inappropriate use of cardio-active medications.

Dual antiplatelet therapy reduced stroke risk in high-risk patients with transient ischaemic attack assessed by ABCD3-I score

BACKGROUND AND PURPOSE

Several clinical trials have demonstrated that dual antiplatelet therapy (DAPT) benefited patients with transient ischaemic attack (TIA) with an ABCD2 score ≥4. The present study aimed to investigate whether the ABCD3-I score could be a more appropriate tool for selection of patients with TIA to receive DAPT in real-world settings.

METHODS

We derived data from the TIA database of The First Affiliated Hospital of Zhengzhou University. The predictive outcome was ischaemic stroke at 90 days. The additive interaction effect was presented by the attributable proportion due to interaction. Kaplan-Meier curves were plotted to present cumulative stroke rates in different risk categories with monotherapy and DAPT. Cox proportional hazards regression was used to determine risk factors associated with stroke.

RESULTS

Among 785 patients, the mean (SD) age was 56.95 (12.73) years and 77 patients (9.8%) had an ischaemic stroke at 90 days. A total of 55.8% of patients (attributable proportion due to interaction; 95% confidence interval, 20.8%-90.9%) were attributed to additive interaction of ABCD3-I score and antiplatelet therapy. Kaplan-Meier curves showed a significant difference between patients receiving monotherapy and DAPT in high-risk patients with TIA (P = 0.021). DAPT reduced 90-day stroke risk in high-risk patients with TIA as assessed independently by ABCD3-I score (adjusted hazard ratio, 0.43; 95% confidence interval, 0.20-0.92, P = 0.031). The benefit did not exist in low- and medium-risk patients by ABCD3-I score (patients with ABCD2 score ≥ 4 or <4).

CONCLUSIONS

High-risk patients with TIA assessed by ABCD3-I score received the most pronounced clinical benefit from early use of DAPT in real-world clinical experience.

Phagraphene nanoribbons: half-metallicity and magnetic phase transition by functional groups and electric field

Magnetic nanomaterials with the desirable nature are the basis for developing future spintronic devices, and research for them is of fundamental interest. Here, we explore the realization of half-metallicity and magnetic phase transition for phagraphene nanoribbons in virtue of functional groups (OH and CN) with different coverage fractions and external electric fields. The first-principles calculations show that a single-edge CN functionalization only makes a intrinsic spin-degenerate semiconducting ribbon converted to a quasi-metal or metal, while a single-edge OH modification leads to an occurrence of the half-semiconducting nature regardless of the coverage fraction of groups. Interestingly, the half-metal behavior for the CN and OH double-edge modified ribbons can be achieved either in the zero-electric-field intrinsic state for most of functionalized systems or at a very low electric field, 0.1 V Å^-1. More importantly, the observed critical electric field for the transition from ferromagnetic to nonmagnetic phase is lowered significantly almost for all systems, this benefits to design a low electric-field-controlling magnetic switch which can reversibly work between both magnetic and nonmagnetic states. The calculated Gibbs free energy confirms that the group-modified ribbons generally hold a more favorable energy stability in most of the cases, facilitating likely experimental realization.

[The expression characteristics and clinical significance of candidate molecular markers in vocal cord leukoplakia]

Objective: To investigate the expression of marker proteins in vocal cord leukoplakia, and to find markers for the early stage of diagnosis and prognosis of precancerous lesions. Methods: The study included 119 cases, 68 cases of vocal cord leukoplakia (22 cases with epithelial simple hyperplasia, 46 cases with epithelial dysplasia), and 51 cases of vocal cords benign lesions(31 cases of vocal cord polyps, 20 cases of Reinke's edema). The expression of p53, Ki-67, p21, Survivin, p16, p27, PTEN, c-Myc and vascular endothelial growth factor (VEGF) in vocal cords leukoplakia were detected, vocal cord benign lesions (vocal cord polyps and Reinke's edema) acted as controls, comparing the expression differences of different pathological tissue. Data was analyzed by SPSS 22.0 software. Results: The expression of p53, p16, Ki-67, VEGF in vocal cord benign lesions and vocal cords leukoplakia with epithelial simple hyperplasia did not show significant differences. There was a grading increase in the positive expression of p53, Ki-67 in the vocal cord leukoplakia with epithelial dysplasia contrasting to those in vocal cord benign lesions and vocal cords leukoplakia with epithelial simple hyperplasia (p53: χ(2)=13.340, P=0.002, Ki-67: χ(2)=53.386, P=0.000). The expression of p27, PTEN, c-Myc in vocal cord benign lesions and vocal cords leukoplakia with epithelial dysplasia did not show significant differences. There was a grading increase in the positive expression of p21 Survivin in vocal cords leukoplakia with epithelial dysplasia contrasting to those in vocal cord benign lesions (P<0.05). Expression of Survivin in vocal cords leukoplakia with mild-moderate epithelial dysplasia showed a significant increase than those in vocal cord benign lesions (P<0.05). The positive expression grade of p21 showed a rising trend (P=0.073) between the different grades of dysplasia. Conclusion: The positive expression grade of p53, Ki-67, p21 Survivin showed an increase in vocal cords leukoplakia with epithelial dysplasia contrasting to those in vocal cord benign lesions, which might be an implication for evaluating the diagnosis and prognosis of precancerous lesions. Expression of p21 was correlated to the degrees of dysplasia and expression of Survivin showed a significant difference in early stage of epithelial dysplasia contrasting to benign lesions.

Nicotine inhibits osteogenic differentiation of human periodontal ligament cells under cyclic tensile stress through canonical Wnt pathway and α7 nicotinic acetylcholine receptor

BACKGROUND AND OBJECTIVES

Nicotine, the main psychoactive component of tobacco, affects cell metabolism, proliferation, adhesion and, importantly, the osteogenic differentiation of fibroblasts. Approximately 15% of all orthodontic patients are adults among who one-fifth are smokers. Hence, it is necessary to have insight into the effects of nicotine on the osteogenic differentiation of hPDLCs during orthodontic tooth movement. This study aimed to investigate the effects and mechanisms of nicotine on the osteogenic differentiation of human periodontal ligament cells (hPDLCs) under the application of cyclic tensile stress.

MATERIAL AND METHODS

hPDLCs were obtained from donor third molars. The hPDLCs were treated with nicotine and/or cyclic tensile stress that was applied with a cell stress plus unit. The effect of nicotine on cell viability was analyzed using the MTT assay. The osteogenic differentiation of hPDLCs was detected by alkaline phosphatase staining, Alizarin Red S staining, quantitative real-time polymerase chain reaction and western blotting.

RESULTS

In combination with cyclic tensile stress, nicotine prevented the tensile stress-induced increase in alkaline phosphatase activity, formation of mineralization nodules and the upregulation of mRNA and protein expression of Runt-related transcription factor 2, transcription factor Sp7 and collagen type I; however, canonical Wnt pathway was activated. Furthermore, the addition of Dickkopf-related protein 1 and α-bungarotoxin counteracted the negative effect of nicotine and rescued the osteogenic differentiation of hPDLCs, respectively.

CONCLUSION

These results indicate that nicotine prevents the increased osteogenic potential of hPDLCs induced by cyclic tensile stress by binding to an α7 nicotinic acetylcholine receptor and activating the canonical Wnt pathway.