Distance-Dependent Evolution of Electronic States in Kagome-Honeycomb Lateral Heterostructures in FeSn

In this work, we demonstrate the formation and electronic influence of lateral heterointerfaces in FeSn containing Kagome and honeycomb layers. Lateral heterostructures offer spatially resolved property control, enabling the integration of dissimilar materials and promoting phenomena not typically observed in vertical heterostructures. Using the molecular beam epitaxy technique, we achieve a controllable synthesis of lateral heterostructures in the Kagome metal FeSn. With scanning tunneling microscopy/spectroscopy in conjunction with first-principles calculations, we provide a comprehensive understanding of the bonding motif connecting the Fe3Sn-terminated Kagome and Sn2-terminated honeycomb surfaces. More importantly, we reveal a distance-dependent evolution of the electronic states in the vicinity of the heterointerfaces. This evolution is significantly influenced by the orbital character of the flat bands. Our findings suggest an approach to modulate the electronic properties of the Kagome lattice, which should be beneficial for the development of future quantum devices.

Theoretical Investigation of Delafossite-Cu2ZnSnO4 as a Promising Photovoltaic Absorber

In the quest for efficient and cost-effective photovoltaic absorber materials beyond silicon, considerable attention has been directed toward exploring alternatives. One such material, zincblende-derived Cu2ZnSnS4 (CZTS), has shown promise due to its ideal band gap size and high absorption coefficient. However, challenges such as structural defects and secondary phase formation have hindered its development. In this study, we examine the potential of another compound, Cu2ZnSnO4 (CZTO), with a similar composition to CZTS as a promising alternative. Employing ab initio density function theory (DFT) calculations in combination with an evolutionary structure prediction algorithm, we identify that the crystalline phase of delafossite structure is the most stable among the 900 (meta)stable CZTO. Its thermodynamic stability at room temperature is also confirmed by the molecular dynamics study. Excitingly, this new phase of CZTO displays a direct band gap where the dipole-allowed transition occurs, making it a strong candidate for efficient light absorptions. Furthermore, the estimation of spectroscopic limited maximum efficiency (SLME) directly demonstrates the high potential of delafossite-CZTO as a photovoltaic absorber. Our numerical results suggest that delafossite-CZTO holds promise for future photovoltaic applications.

Stacking Faults and Topological Properties in MnBi2Te4: Reconciling Gapped and Gapless States

Despite theoretical predictions of a gapped surface state for the magnetic topological insulator MnBi2Te4 (MBT), there has been a series of experimental evidence pointing toward gapless states. Here, we theoretically explore how stacking faults could influence the topological characteristics of MBT. We envisage a scenario that a stacking fault exists at the surface of MBT, causing the uppermost layer to deviate from the ground state and its interlayer separation to be expanded. This stacking fault with modulated interlayer couplings hosts a nearly gapless state within the topmost layer due to charge redistribution as the outermost layer recedes. Furthermore, we find evidence of spin-momentum locking and preservation of weak band inversion in the gapless surface state, suggesting the nontrivial topological surface states in the presence of the stacking fault. Our findings provide a plausible elucidation to the long-standing conundrum of reconciling the observation of gapped and gapless states on MBT surfaces.

[The implementation and management of disease risk reduction claims in the European Union and the United States]

The improvement of food labeling can improve consumers' health awareness, reduce the burden of chronic diseases on the health and economy, and promote the development of the healthy food industry. Disease Risk Reduction Claim has been developed in European Union and the U.S. for over 20 years, with mature management methods and experience, but it is still lacking in China. Learning and drawing on the international management experience of food disease risk reduction claims can assist China to establish food disease risk reduction claims and improve the food health claims and labeling system.

Low Ohmic contact resistance and high on/off ratio in transition metal dichalcogenides field-effect transistors via residue-free transfer

Beyond-silicon technology demands ultrahigh performance field-effect transistors. Transition metal dichalcogenides provide an ideal material platform, but the device performances such as the contact resistance, on/off ratio and mobility are often limited by the presence of interfacial residues caused by transfer procedures. Here, we show an ideal residue-free transfer approach using polypropylene carbonate with a negligible residue coverage of ~0.08% for monolayer MoS2 at the centimetre scale. By incorporating a bismuth semimetal contact with an atomically clean monolayer MoS2 field-effect transistor on hexagonal boron nitride substrate, we obtain an ultralow Ohmic contact resistance of ~78 Ω µm, approaching the quantum limit, and a record-high on/off ratio of ~1011 at 15 K. Such an ultra-clean fabrication approach could be the ideal platform for high-performance electrical devices using large-area semiconducting transition metal dichalcogenides.

Regional inequality of socioeconomic status and the prevalence of hypertension between rural and urban areas

Background

Lower socioeconomic status (SES) is associated with greater burdens of cardiovascular disease in a community. The regional disparity of SES may result in an uneven distribution of hypertension (HTN) by a region. This study aims to analyze the regional disparity in the SES and HTN burden between rural and urban areas of the Korea.

Methods

We used data from the Korea National Health and Nutrition Examination Survey (KNHANES) V (2010–2012), VI (2013–2015), and VII (201–2018). We analyzed 11,206 and 1739 subjects from Seoul metropolitan and rural area (Gangwon province), respectively. We compared socioeconomic characteristics, the distribution of HTN between two regions. Finally, we performed a multivariate logistic regression adjusting for traditional CV risk factors and SES status to examine differences in the prevalence of HTN.

Results

Subjects in Gangwon province were older than Seoul (54.6±0.4 vs 49.4±0.2 years old, p<0.001). The proportions of subjects with low economic status and low education level were significantly higher in Gangwon province compared to Seoul (low economic status; 25.6 vs 14.4%, p<0.001, low education level; 35.3 vs 16.5%, p<0.001). Mean systolic blood pressure (SBP) was higher in Gangwon compared to Seoul (121.6±0.4 vs 118.1±0.2 mmHg, p<0.001). In the longitudinal trend from KNHANES V to VII, the difference of SBP between the two regions increased (Figure). The age-matched prevalence of HTN was significantly higher in Gangwon compared to Seoul (23.8 vs 21.6%, p<0.05), and the difference of prevalence of HTN by regions longitudinally increased (Figure). In the univariate analysis, the residency in Gangwon was associated with the presence of HTN (reference: Seoul, OR=1.63; 95% CI: 1.45–1.83). In the multivariate logistic regression model, the residency in Gangwon was not associated, however, low economic status and low education level were significantly associated with the presence of HTN (economic status, OR=1.39; 95% CI: 1.17–1.67, education level, OR=1.88; 95% CI: 1.57–2.24).

Conclusion

The SES status was lower and the prevalence of HTN was higher in Gangwon compared to Seoul. The burden of HTN longitudinally increased in Gangwon, but not in Seoul. The poor SES was significantly associated with HTN. It suggests that the inequalities of SES in Gangwon may contribute to the increasing prevalence of HTN. The regional and individual disparity of SES should be considered in the establishment of public health strategies for HTN.

Funding Acknowledgement

Type of funding sources: None.

Impact of dementia and drug compliance on patients with acute myocardial infarction

Background

There has been a worrying rise in the number of people with dementia, especially with many of them also suffering from acute myocardial infarction (AMI), a disease with a high mortality rate.

Purpose

We evaluated the impact of dementia on the mortality of patients with AMI and how drug compliance affects this relationship.

Methods

The data were derived from National Health Insurance Service-Senior. The total number of patients diagnosed with AMI for the first time between 2007 and 2013 was 16,835, among whom 2,021 had dementia. Medication possession ratio (MPR) was used to assess medication adherence.

Results

AMI patients with dementia had unfavorable baseline characteristics; they had significantly higher risk of all-cause mortality (Hazard ratio [HR]: 2.49; 95% confidence interval (CI): 2.34–2.66; P<0.001) and lower MPR (aspirin: 21.9% vs. 42.8%; P<0.001). AMI patients were stratified by presence of dementia and medication adherence, and the survival rate was the highest among those with no dementia and good adherence. followed by those with no dementia and poor adherence, those with dementia and good adherence, and those with dementia and poor adherence. The multivariable analysis revealed that dementia (HR: 1.64; 95% CI: 1.53–1.75; P<0.001) and poor adherence to medication (HR: 1.60; 95% CI: 1.49–1.71; P<0.001) had a significant association with all-cause mortality in AMI patients.

Conclusions

AMI patients with dementia have a higher mortality rate. Patients with dementia have poorer medication adherence than those without, negatively affecting their prognosis.

Funding Acknowledgement

Type of funding sources: None.

Oxidation-enhanced thermoelectric efficiency in a two-dimensional phosphorene oxide

We performed density functional theory calculations to investigate the thermoelectric properties of phosphorene oxide (PO) expected to form by spontaneous oxidation of phosphorene. Since thermoelectric features by nature arise from the consequences of the electron-phonon interaction, we computed the phonon-mediated electron relaxation time, which was fed into the semiclassical Boltzmann transport equation to be solved for various thermoelectric-related quantities. It was found that PO exhibits superior thermoelectric performance compared with its pristine counterpart, which has been proposed to be a candidate for the use of future thermoelectric applications. We revealed that spontaneous oxidation of phosphorene leads to a significant enhancement in the thermoelectric properties of n-doped phosphorene oxide, which is attributed to the considerable reduction of lattice thermal conductivity albeit a small decrease in electrical conductivity. Our results suggest that controlling oxidation may be utilized to improve thermoelectric performance in nanostructures, and PO can be a promising candidate for low-dimensional thermoelectric devices.

Symmetry Dictated Grain Boundary State in a Two-Dimensional Topological Insulator

Grain boundaries (GBs) are ubiquitous in solids and have been of central importance in understanding the nature of polycrystals. In addition to their classical roles, topological insulators (TIs) offer a chance to realize GBs hosting distinct topological states that can be controlled by their crystal symmetries. However, such roles of crystalline symmetry in two-dimensional (2D) TIs have not been definitively measured yet. Here, we present the first direct evidence of a symmetry-enforced metallic state along a GB in 1T'-MoTe₂, a prototypical 2D TI. Using scanning tunneling microscopy, we show a metallic state along a GB with nonsymmorphic lattice symmetry and its absence along another boundary with symmorphic symmetry. Our atomistic simulations demonstrate in-gap Weyl semimetallic states for the former, whereas they demonstrate gapped states for the latter, explaining our observation well. The observed metallic state, tightly linked to its crystal symmetry, can be used to create a stable conducting nanowire inside TIs.

Evolution of structural and magnetic properties in iron oxide nanoparticles synthesized using Azadirachta indica leaf extract

The novel superparamagnetic nature of magnetic nanoparticles (MNPs) has received significant attention in the wide variety of fields. However, the prerequisites to use these MNPs, particularly in biomedical applications are biocompatibility and high saturation magnetization (Ms). Thus, the development of a sustainable approach for the synthesis of biocompatible MNPs, which utilizes the redox properties of natural compounds from plant extracts, is highly desired. Herein, we have examined the growth of phase selective MNPs synthesized using Azadirachta indica (Neem) extract as a reducing and capping agent. The physical and biological properties of MNPs synthesized with the modified green hydrothermal method at different reaction times and temperatures were investigated. It was observed that the reaction time and temperature strongly modulated the magnetic and structural characteristics of MNPs. At lower reaction time and temperature of 200 °C for 2 h, primarily iron oxalate hydrate (Fe(C2O4).2(H2O)) was formed. Further, with increasing reaction temperature, the phase transformation from iron oxalate hydrate to pure magnetite (Fe3O4) phase was observed. The MNPs prepared with optimum conditions of 220 °C for 4 h show superparamagnetic nature with improved Ms value of 58 emu g−1. The antibacterial study of MNPs against gram-positive bacteria Staphylococcus aureus showed that the MNPs inhibits the growth of bacteria with the least inhibitory MNPs concentration of 6 μl. Thus, the MNPs obtained by this modified biogenic approach will widen the scope and their applicability in future biomedical applications.

Association of exposure to secondhand smoke at home with early age at menarche in South Korea

OBJECTIVES

The secular trend in age at menarche (AAM) has declined both worldwide and in Korea. Early AAM is associated with the risk of several diseases, reproductive capacity, and psychological problems. We aimed to investigate the relationship between secondhand smoke (SHS) exposure at home and early puberty onset using AAM in Korean adolescents.

STUDY DESIGN

This is a retrospective cross-sectional study.

METHODS

This study used data from the Korea Youth Risk Behavior Web-based Survey 2014-2015. We used the mean AAM (12.2 years) as a determinant of early AAM. After the exclusion of girls without menarche or who did not respond, the total population comprised 63,618 participants. We categorized AAM as 'early' and 'average or late.' Adolescents with SHS exposure were assigned to the 'never exposed,' 'light exposure,' and 'heavy exposure' groups. Multiple logistic regression analyses were performed.

RESULTS

We observed a positive association, approximately 1.12 times, between early AAM and high SHS exposure (odds ratio [OR], 1.12; 95% confidence interval [CI], 1.05-1.19). Girls who started smoking before the age of 12 years (OR, 1.68; 95% CI, 1.41-1.99) showed a stronger association with early AAM than non-smokers. Active smoking showed a stronger association with early AAM. Never smokers with high SHS exposure at home were 1.13 times likelier to have an early AAM (OR, 1.13; 95% CI, 1.05-1.22) than those without SHS exposure.

CONCLUSIONS

In addition to active smoking, SHS may also be a risk factor for early AAM. Education aimed at active and secondhand smoking prevention is needed to protect children against early AAM.

Effect of Sedentary Time on the Risk of Orthopaedic Problems in People Aged 50 Years and Older

OBJECTIVE

Many people experience orthopaedic problems (OPPs), such as knee joint pain, hip joint pain, low back pain, and knee stiffness in their lifetimes. OPPs can impair lower extremity function, cause depression, and worsen quality of life. The aim of this study was to investigate the association between sedentary time (SDT) and OPPs.

DESIGN

Retrospective cross-sectional study.

SETTING

This study used data from the 2014-2015 Korea National Health and Nutrition Examination Survey. Survey participants with previous or current osteoarthritis or rheumatoid arthritis, as diagnosed by a doctor, were excluded. OPPs were defined as knee joint pain, hip joint pain, low back pain, and knee stiffness. The cut-off value for SDT was 7.5 hours/day. The study population comprised 3,671 people (1,856 men and 1,815 women), all of whom were ≥50 years-old. Multiple logistic regression analyses were performed.

RESULTS

A total of 328 men (17.7%) and 519 women (28.6%) had OPPs. Men with SDTs ≥7.5 hours had a greater risk of OPPs than did men with SDTs <7.5 hours (odds ratio [OR], 1.45; 95% confidence interval [CI], 1.08-1.93). A pink-collar job, physical inactivity during leisure time, and passive (e.g. riding in a car or train) versus active (e.g. walking or riding a bicycle) transportation predicted OPPs in men with SDTs ≥7.5 hours. SDT was a risk factor for knee joint pain in men (OR, 1.80; 95% CI, 1.11-2.92) and hip joint pain in women (OR, 2.05; 95% CI, 1.35-3.11).

CONCLUSIONS

In men, prolonged SDT is a risk factor for OPPs. More physical activity programmes should be launched at the community level for people ≥50 years-old to reduce the occurrence of OPPs.

Two-dimensional Dirac fermions on oxidized black phosphorus

We explore the oxidation of a single layer of black phosphorus using ab initio density functional theory calculations. We search for the equilibrium structures of phosphorene oxides, POx with various oxygen concentrations x (0 ≤ x ≤ 1). By evaluating the formation energies with diverse configurations and their vibrational properties for each of various x values, we identify a series of stable oxidized structures with x and confirm that the oxidation occurs naturally. We also find that oxidation makes some modes from the P-O bonds and P-P bonds IR-active implying that the infrared spectra can be used to determine the degree of oxidation of phosphorene. Our electronic structure calculations reveal that the fully oxidized phosphorene (PO) has a direct band gap of 0.83 eV similar to the pristine phosphorene. Intriguingly, the PO possesses two nonsymmorphic symmetries with the inversion symmetry broken, guaranteeing symmetry-protected band structures including the band degeneracy and four-fold degenerate Dirac points. Our results provide an important guide in the search for the rare example of a Dirac semimetal with a higher level of degeneracy, giving significant insight into the relations between the symmetry of the lattice and band topology of electrons.

1272Physical activity and mortality with and without cardiovascular disease

Background/Introduction

Physical activity has been shown to reduce mortality in a dose-response fashion. Current guidelines recommend 500 to 1,000 MET-min per week of regular physical activity. However, evidence is limited regarding the specific dose-response relationship in patients with cardiovascular disease.

Purpose

Our aim was to compare the impact of physical activity on mortality in primary versus secondary cardiovascular prevention.

Methods

We analyzed 441,798 individuals with complete information on physical activity levels between 2009 and 2015 were extracted from a population-based cohort (National Health Insurance Service-National Health Screening cohort). Physical activity measured by self-report questionnaires. A rating of 2.9, 4.0, and 7.0 METs were assigned for light-intensity, moderate-intensity, and vigorous-intensity activities, respectively. Physical activity-related energy expenditure (MET-min/week) was calculated by summing the product of frequency, intensity, and duration. The level of physical activity was classified into 0, 0 to 499, 500 to 999, 1,000 to 1,499, and ≥1,500 MET-min/week. Study participants were stratified by the presence of cardiovascular disease, defined as prior myocardial infarction, ischemic heart disease, prior stroke, and/or chronic heart failure. The main study outcome was all-cause mortality. The median follow-up duration was 5.9 years.

Results

Individuals with cardiovascular disease had lower physical activity levels and a higher risk of mortality than those without cardiovascular disease. There was an inverse relationship between the physical activity level and the mortality risk in both groups. The benefit in the secondary prevention group was shown to be greater than that in the primary prevention group: every 500 MET-min/week increase in physical activity resulted in a 14% and 7% risk reduction in mortality in the secondary and primary prevention groups, respectively (interaction P<0.001). In addition, while individuals without cardiovascular disease benefited the most between 0 and 500 MET-min/week of physical activity, the benefit in those with cardiovascular disease continued above 500 to 1,000 MET-min/week. The adjusted mortality risk of individuals with cardiovascular disease who performed a high level of physical activity (≥1,000 MET-min/week) was shown to be comparable to or lower than that of their counterparts without cardiovascular disease.

Adjusted risk of mortality

Conclusion

Individuals with cardiovascular disease may benefit from physical activity to a greater extent than do healthy subjects without cardiovascular disease. Clinicians should encourage patients with cardiovascular disease to maintain a physically active lifestyle as much as possible.

Closing the Surface Bandgap in Thin Bi2Se3/Graphene Heterostructures

Topological insulator (TI), a band insulator with topologically protected edge states, is one of the most interesting materials in the field of condensed matter. Bismuth selenide (Bi₂Se₃) is the most spotlighted three-dimensional TI material; it has a Dirac cone at each top and bottom surface and a relatively wide bandgap. For application, suppression of the bulk effect is crucial, but in ultrathin TI materials, with thicknesses less than 3 QL, the finite size effect works on the linear dispersion of the surface states, so that the surface band has a finite bandgap because of the hybridization between the top and bottom surface states and Rashba splitting, resulting from the structure inversion asymmetry. Here, we studied the gapless top surface Dirac state of strained 3 QL Bi₂Se₃/graphene heterostructures. A strain caused by the graphene layer reduces the bandgap of surface states, and the band bending resulting from the charge transfer at the Bi₂Se₃-graphene interface induces localization of surface states to each top and bottom layer to suppress the overlap of the two surface states. In addition, we verified the independent transport channel of the top surface Dirac state in Bi₂Se₃/graphene heterostructures by measuring the magneto-conductance. Our findings suggest that the strain and the proximity effect in TI/non-TI heterostructures may be feasible ways to engineer the topological surface states beyond the physical and topological thickness limit.

[Magnetic resonance imaging findings and differential diagnosis of renal epithelioid angiomyolipoma comparing with renal no-epithelioid angiomyolipoma]

Objective: To investigate whether MRI findings can differentiate renal epithelioid angiomyolipoma (EAML) from renal no-epithelioid (typical) angiomyolipoma. Methods: A total of 44 patients were collected from General Hospital of PLA.These cases were obtained from January 2009 to June 2015.To retrospectively analyze these mainly MRI findings among 12 cases of EAML (age from 27 to 61 years, male 2 cases, female 10 cases, mean age was 46.7 years); 32 cases of renal no-epithelioid AML (age from 34 to 70 years old, male 9 cases, female 23 cases, mean age was 53.4 years old) as case control study. MRI findings included gender, T(2)WI, the signal on gross fat, pseudocapsle, necrosis or cystic degeneration, DWI, hemorrhage and the peak in three phases of dynamic enhancement.All data were analyzed statistically using SPSS version 19.0 (IBM, Armonk, NY, USA). χ(2) test and a single order chart were used to analyze the enumeration data. Results: Comparing with renal no-epithelioid angiomyolipoma, minimal fat, necrosis or cystic degeneration and hemorrhage were statistical significance. P values were 0.002, 0.007, 0.025, respectively.Gender, solid components of tumors on T(2)WI, the signal of DWI, pesudocapsule and the peak of enhancement had no statistical significance. P values were 0.863, 0.053, 0.479, 0.460, respectively. Conclusion: Comparing with renal no-epithelioid AML, necrosis or cystic degeneration and hemorrhage with minimal fat are characteristic MRI findings of EAML.

A "non-dynamical" way of describing room-temperature paramagnetic manganese oxide

We present a new approach based on static density functional theory (DFT) to describe paramagnetic manganese oxides, representative paramagnetic Mott insulators. We appended spin noncollinearity and a canonical ensemble to the magnetic sampling method (MSM), which is one of the supercell approaches based on the disordered local moment model. The combination of the noncollinear MSM (NCMSM) with DFT+U represents a highly favorable computational method called NCMSM+U to accurately determine the paramagnetic properties of MnO with moderate numerical cost. The effects of electron correlations and spin noncollinearity on the properties of MnO were also investigated. We found that the spin noncollinearity plays an important role in determining the detailed electronic profile and precise energetics of paramagnetic MnO. Our results illustrate that the NCMSM+U approach may be used for insulating materials as an alternative to the ab initio framework of dynamic mean field theory based on DFT in the simulation of the room-temperature paramagnetic properties.

Enhanced Thermoelectric Properties in a New Silicon Crystal Si24 with Intrinsic Nanoscale Porous Structure

Thermoelectric device is a promising next-generation energy solution owing to its capability to transform waste heat into useful electric energy, which can be realized in materials with high electric conductivities and low thermal conductivities. A recently synthesized silicon allotrope of Si₂₄ features highly anisotropic crystal structure with nanometer-sized regular pores. Here, based on first-principles study without any empirical parameter we show that the slightly doped Si₂₄ can provide an order-of-magnitude enhanced thermoelectric figure of merit at room temperature, compared with the cubic diamond phase of silicon. We ascribe the enhancement to the intrinsic nanostructure formed by the nanopore array, which effectively hinders heat conduction while electric conductivity is maintained. This can be a viable option to enhance the thermoelectric figure of merit without further forming an extrinsic nanostructure. In addition, we propose a practical strategy to further diminish the thermal conductivity without affecting electric conductivity by confining rattling guest atoms in the pores.

Delayed viral suppression during antiviral therapy is associated with increased hepatocellular carcinoma rates in HBeAg-positive high viral load chronic hepatitis B

The treatment option in chronic hepatitis B (CHB) patients with persistent low-level viremia despite entecavir or tenofovir monotherapy is unclear. This study investigated the development of hepatocellular carcinoma (HCC) or cirrhosis in hepatitis B e antigen (HBeAg)-positive high viral load CHB patients, according to the time needed to achieve complete viral suppression. A total of 325 HBeAg-positive CHB patients with high viral load who were recently started on antiviral therapy with entecavir or tenofovir were included. The enrolled patients were divided into 2 groups with 4 separate criteria based on the time needed to achieve complete viral suppression: within 1, 2, 3 or 4 years of therapy initiation. The outcomes were development of HCC and cirrhosis. The cumulative incidence of HCC was significantly higher in patients failing complete viral suppression within 1 year (hazard ratio (HR), 4.54; 95% confidence interval (CI), 1.03-19.93; P = .045) or 2 years (HR, 3.38; 95% CI, 1.24-9.23; P = .018), than patients who achieved complete viral suppression within 1 or 2 years, respectively. Cumulative incidence of cirrhosis was also significantly higher in patients failing suppression within 1 year (HR, 1.95; 95% CI, 1.04-3.66; P = .037) or 2 years (HR, 2.44; 95% CI, 1.41-4.22; P = .001). When the time for achieving viral suppression exceeded 2 years, the cumulative incidence of HCC or cirrhosis was not different regardless of viral suppression. Complete hepatitis B virus suppression within 2 years of antiviral therapy initiation is associated with risk reduction in HCC or cirrhosis development.

Latent Order in High-Angle Grain Boundary of GaN

We report the existence of latent order during core relaxation in the high-angle grain boundaries (GBs) of GaN films using atomic-resolution scanning transmission electron microscopy and ab initio density functional theory calculations. Core structures in the high-angle GBs are characterized by two pairs of Ga-N bonds located next to each other. The core type correlates strongly with the bond angle differences. We identify an order of core relaxation hidden in the high-angle GBs by further classifying the 5/7 atom cores into a stable 5/7 core (5/7(S)) and a metastable 5/7 core (5/7(M)). This core-type classification indicates that metastable cores can exist at real high-angle GBs under certain circumstances. Interestingly, 5/7(M) exhibits distinct defect states compared to 5/7(S), despite their similar atomic configurations. We investigate the reconstruction of defect states observed in 5/7(M) by analyzing the real-space wave functions. An inversion occurred between two localized states during the transition from 5/7(S) to 5/7(M). We suggest an inversion mechanism to explain the formation of new defect states in 5/7(M).

Abstract P3-01-16: How hot is enough for accurate sentinel lymph node axillary staging in breast cancer?

Purpose:

Sentinel lymph node (SLN) biopsy is a well-established procedure for staging of the axilla in early-stage breast cancer and has replaced axillary lymph node dissection as the standard of care in patients with clinically lymph node–negative axilla. No consensus exists about the number of sentinel lymph nodes (SLNs) that should be removed based on radioactivity counts in breast cancer, although the “10% rule” is often used. In order to determine the frequency with which the hottest SLN 'fails' to be pathologically positive, and to determine which criteria best define the radioactive lymph node to be removed, we reviewed and analyzed our cases in which more than one SLN was detected and where there was also at least one pathologically positive node.

Methods:

We retrospectively studied 1062 breast cancer patients who underwent lymphoscintigraphy by injection of radioactive colloid and SLN biopsy between 2006 and 2015, with intraoperative determination of radioactive counts of nodes by a gamma probe.

Results:

A total of 247 patients (23.3%) had more than 1 SLN removed (mean 2.29); 53 patients (21.5%) had nodal metastases. Of the node-positive patients, the hottest SLN was positive in 90.6% (48 of 53). The lowest radioactive count of a positive SLN was 32% of that of the hottest node.

Conclusions:

In our study, most positive SLNs had the highest radioactivity and the hottest lymph node was not the pathologically positive node only in 9.4 %. Our institutional experience indicates that to obtain an acceptable false-negative rate, nodes should be removed until the 10% rule is met.

Citation Format: Lee MH, Kang SH, Cho J. How hot is enough for accurate sentinel lymph node axillary staging in breast cancer? [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-01-16.

Rifaximin treatment is associated with reduced risk of cirrhotic complications and prolonged overall survival in patients experiencing hepatic encephalopathy

BACKGROUND

Rifaximin might decrease the risk of portal hypertension-related complications by controlling small intestinal bacterial overgrowth.

AIM

To evaluate whether rifaximin was associated with the risk of death and cirrhotic complications.

METHODS

We conducted a retrospective study that included 1042 patients experiencing hepatic encephalopathy (HE): 421 patients without hepatocellular carcinoma (HCC; the non-HCC cohort) and 621 patients with HCC (the HCC cohort). The primary endpoint was overall survival and secondary endpoints were recurrence of HE and the development of spontaneous bacterial peritonitis (SBP), hepatorenal syndrome (HRS) and variceal bleeding.

RESULTS

In the non-HCC cohort, 145 patients received rifaximin plus lactulose (the rifaximin group) and 276 patients received lactulose alone (the control group). The multivariate analysis revealed that rifaximin was significantly associated with lower risk of death (adjusted hazard ratio [aHR], 0.697; P = .024) and reduced the risk of recurrent HE (aHR, 0.452; P < .001), SBP (aHR, 0.210; P < .001) and variceal bleeding (aHR, 0.425; P = .011) but not HRS (aHR, 0.598; P = .08). In the HCC cohort, 173 patients received rifaximin plus lactulose and 448 patients received lactulose. Rifaximin was not associated with the risk of death (aHR, 1.177; P = .121). Rifaximin was associated with lower risk of SBP (aHR, 0.323; P < .001) but not with variceal bleeding (aHR, 0.660; P = .104) or recurrent HE (aHR, 0.689; P = .057). The risk of Clostridium difficile-associated diarrhoea was not different between the groups (aHR, 0.028; P = .338).

CONCLUSIONS

In patients without HCC, rifaximin treatment was significantly associated with prolonged overall survival and reduced risks of spontaneous bacterial peritonitis, variceal bleeding and recurrent hepatic encephalopathy.

Extremely high electrical conductance of microporous 3D graphene-like zeolite-templated carbon framework

We report the remarkably high electrical conductance of microporous 3D graphene-like carbons that were formed using lanthanum (La)-catalyzed synthesis in a Y zeolite (LaY) template investigated using conductive atomic force microscopy (C-AFM) and theoretical calculations. To uncover the relation between local electrical conductance and the microporous structures, we tuned the crystallographic ordering of LaY-templated carbon systems by changing the heating temperature. The structure of the LaY-templated carbon prepared at the higher temperature has graphene-like sp² hybridized bonds, which was confirmed using high-resolution transmission electron microscopy and X-ray diffraction measurements. C-AFM current–voltage spectroscopy revealed that the local current flow in the LaY-templated carbon depends on the quantity of C–C bonds within the narrow neck between the closed supercages (i.e. there are three types of carbon: carbon with heat treatment, carbon without heat treatment, and carbon synthesized at low temperature). The difference in electrical conductance on the LaY-templated carbon was also confirmed via theoretical computation using the Boltzmann transport theory and the deformation potential theory based on the density functional theory. These results suggest that the degree of order of the pores in the 3D zeolite-templated carbon structures is directly related to electrical conductance.

Low appendicular muscle mass is associated with mortality in peritoneal dialysis patients: a single-center cohort study

BACKGROUND/OBJECTIVES

There are few studies of the association between low appendicular muscle mass (LAM) and clinical outcomes in peritoneal dialysis (PD) patients. We aimed to determine the clinical association between LAM and clinical outcomes in PD patients.

SUBJECT/METHODS

We reviewed all PD patients who underwent PD between January 2001 and April 2014. Each patient's appendicular lean mass was estimated using dual-energy X-ray absorptiometry. The appendicular muscle mass index (AMI) was calculated using total appendicular lean mass (kg) over body mass index (kg/m²). The cut-off AMI value for LAM was <0.789 for men and <0.512 for women.

RESULTS

The number of patients in the Non-LAM and LAM groups was 328 and 303, respectively. The median follow-up durations in the Non-LAM and LAM groups were 47 and 49 months, respectively. The numbers of deaths in the Non-LAM and LAM groups were 96 (29.3%) and 160 (52.8%), respectively. In a comparison with the Non-LAM group, the hazard ratio in the LAM group was 1.74 (95% confidence interval (CI), 1.35-2.24) in univariate and 1.71 (95% CI, 1.28-2.26) in multivariate Cox regression analysis. In addition, the hazard ratio for a 0.1 increase in baseline AMI was 0.89 (95% CI, 0.84-0.95) in univariate analysis and 0.84 (95% CI, 0.76-0.91) in multivariate analysis. Analyses using the 1-year AMI showed trends similar to those for the initial AMI.

CONCLUSIONS

Our study showed the association of LAM with mortality in the incident PD patients.

Abstract P1-10-25: Intrathoracic paclitaxel chemotherapy for malignant pleural effusion in breast cancer

Background: Malignant pleural effusion in breast cancer has been associated with poor prognosis which median survival rate is 5–16 months. The response rate of local treatment has been very low and in some case, complications have resulted in death.

Patients and methods: We investigated the efficacy and safety of paclitaxel, as an intrapleural chemotherapeutic agent. From January 2006 to June 2015, total 35 times of intrapleural chemothepapy were performed in 26 breast cancer patients who had developed malignant pleural effusion. They were infused 120mg/m2 of paclitaxel through a chest tube, which was clamped for 48 hours. The chest tube was maintained until drainage was reduced to less than 50-100 mL/day.

Results: Mean follow up period after intrapleural chemotherapy was 11 months.The average time of indwelling with a chest tube after intrapleural chemotherapy was 9.7 days.

Mean progression free survival was 7.8 Months. During the follow-up period, 5 patients had no progression of pleural effusion and 2 of them were free from progression for more than 36 months. In 26 attempts, there were effective and could remove chest tube otherwise In 9 attempts, there were no improvement after intrapleural chemotherapy. 1 patients received a second round of ipsilateral intrapleural chemotherapy and had no response unlike earlier attempts. There were 3 severe adverse effect related death caused by respiratory failure with or without G4 neutropenia.

Conclusion: Intrapleural paclitaxel chemotherapy is helpful for some cases of uncontrolled pleural effusion in that reduce the duration of hospital stay and improve quality of life. But it will be determined carefully, considering the side effects and response rate of treatment.

Citation Format: Yeu KJ, Park J, Choi JE, Kang SH, Lee SJ. Intrathoracic paclitaxel chemotherapy for malignant pleural effusion in breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-10-25.

Abstract P5-01-10: Correlation of apparent diffusion coefficient with standardized uptake value in invasive lobular carcinoma of breast using in hybrid 18F-FDG PET/MR

Purpose: To compare the apparent diffusion coefficient (ADC) with maximum standardized uptake values (SUV) derived from combined 18F-FDG PET/MRI in invasive lobular carcinoma (ILC) patients.

Methods: From 2012 Aug to 2015 Feb, 53 women with histologically proven ILC (mean age, 50.3 ± 7.7 y-o) underwent hybrid 18F-FDG PET/MR (Siemens Biograph mMR) scan for preoperative assessment. During PET acquisition, simultaneous diffusion-weighted imaging (DWI, b values: 0, 400, 800 s/mm2) was performed using breast coil. ILC over than 2 Cm in size were analyzed. Regions of interest (ROI) were drawn covering the entire ILC on the attenuation-corrected PET-image and the monoexponential ADC-map on PET/MR workstation. All the patients were received surgical treatment within 3 weeks after scan. Spearman rank correlation coefficient (ρ) was calculated to examine the correlation between SUVmax and ADC value.

Results: Total 25 ILC (5.4±1.3 cm; 2.1-6.3 cm) of 22 women were enrolled. 24 ILC showed ER (+)/PR (+) and all ILC showed HER2 (-). 15 patients were confirmed metastatic axillary lymph nodes. The mean of SUVmax was 2.14 ± 2.2 (0.91-11.9) and mean of ADC was 1.02 ×10-3 (0.82 -1.31 ×10-3) mm2/s. Higher histologic grade was correlated with higher SUV (ρ = -0.6, p=0.001). And SUV showed inverse correlation with ADC (ρ = -0.48, p=0.016).

Conclusion: The present data show inverse correlation between increased glucose-metabolism and cellularity in ILC patients. 18F-FDG PET and DWI thus may offer complementary information for the evaluation of treatment response in ILC.

Citation Format: Choi JE, Kang SH, Lee SJ, Kong EJ. Correlation of apparent diffusion coefficient with standardized uptake value in invasive lobular carcinoma of breast using in hybrid 18F-FDG PET/MR. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-01-10.

Abstract P3-13-06: The efficacy and long term results of intraoperative frozen section analysis to access resection margin in ductal carcinoma in situ

Introduction

Breast conserving surgery (BCS) is a standard procedure for early breast cancer and resection margin state is the most important risk factor of local recurrence. Re-operation is generally conducted in 20∼40% after initial BCS to achieve negative margins, especially in breast cancer with carcinoma in situ components. In this study, we analyzed the long-term follow up results and efficacy of BCS using intraoperative frozen section analysis to access resection margin in ductal carcinoma in situ (DCIS) patients.

Methods

Between 2004 and 2006, 1016 patients were diagnosed with primary breast cancer and received breast cancer surgery. Among them, BCS was attempted as an initial operation for 523 patients. Superior, inferior, medial and lateral margin of resected specimen were evaluated according to the intraoperative frozen section analysis. If tumor cells existed less than 2mm from resected specimen margin, intraoperative further resection was done and if the further resection was impossible, initial BCS was converted to mastectomy. All medical records and pathologic reports were reviewed retrospectively.

Results

Of the 523 patients who had to undergo BCS, 13.3% (70/523) were converted to mastectomy during initial BCS. The number of the patients who had either only DCIS or invasive carcinoma c carcinoma in situ component was 372 (71.1%, 372/523) and 17.2% (64/372) were converted to mastectomy. One hundred fifty one (28.9%, 151/523) patients had only invasive carcinoma and 3.97% (6/151) were converted to mastectomy. In this study, we analyzed 94 patients who had to undergo BCS with DCIS. The rate of intraoperative conversion to mastectomy was 13.8% (13/94) and 81 patients had successful BCS with 0∼3 times of intraoperative frozen section analysis. There were no differences between patients who had BCS and final mastectomy in clinicopathologic characteristics such as physical examination of tumor, age of patients, DCIS subtypes, nuclear polymorphism, presence of necrosis, ER, PR, HER2 and Ki67. After permanent biopsy was reported, in 5 patients, resected specimen had tumor cells within less than 2mm from resected margin, not inked margin. They had no reoperations and no recurrences. Mean follow up period was 76.6 months. One locoregional and 3 local recurrences in BCS patients and 1 local recurrence in mastectomy patients were found. There was no difference in disease free survival between two groups (95.1% vs 92.3%, p=0.659). In these DCIS patients, reoperation rate was 0%.

Conclusion

Intraoperative frozen section analysis during BCS to access resection margin helps to avoid reoperations and increase intraoperative success rate of BCS in DCIS. It also shows oncological safe long term results. Further studies are needed to resolve the problem with cost-effectiveness of intraoperative frozen section analysis.

Citation Format: Choi JE, Yeu KJ, Park JY, Kang SH, Lee SJ, Bae YK. The efficacy and long term results of intraoperative frozen section analysis to access resection margin in ductal carcinoma in situ. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-13-06.

The determining factor of a preferred orientation of GaN domains grown on m-plane sapphire substrates

Epitaxial lateral overgrowth in tandem with the first-principles calculation was employed to investigate the determining factor of a preferred orientation of GaN on SiO2-patterned m-plane sapphire substrates. We found that the (100)-orientation is favored over the (10)-orientation in the region with a small filling factor of SiO₂, while the latter orientation becomes preferred in the region with a large filling factor. This result suggests that the effective concentration determines the preferred orientation of GaN: the (100)- and (10)-orientations preferred at their low and high concentrations, respectively. Our computational study revealed that at a low coverage of Ga and N atoms, the local atomic arrangement resembles that on the (10) surface, although the (100) surface is more stable at their full coverage. Such a (10)-like atomic configuration crosses over to the local structure resembling that on the (100) surface as the coverage increases. Based on results, we determined that high effective concentration of Ga and N sources expedites the growth of the (10)-orientation while keeping from transition to the (100)-orientation. At low effective concentration, on the other hand, there is a sufficient time for the added Ga and N sources to rearrange the initial (10)-like orientation to form the (100)-orientation.

Clinical results of treatment of garden type 1 and 2 femoral neck fractures in patients over 70-year old

INTRODUCTION

We retrospectively analyzed the clinical results of treatment of impacted or undisplaced femoral neck fractures (Garden types 1 and 2) by osteosynthesis in elderly patients >70-year old.

MATERIALS AND METHODS

We retrospectively reviewed the radiological results of 52 patients who were followed up for at least 6 months from April 2002 to December 2008. The average age of the patients was 77.6 years (range 70-97 years), and 38 patients were females. The mean follow-up period was 11.7 months (range 6-19 months). Thirteen cases were Garden type 1 fractures, and 39 were Garden type 2 fractures. We assessed the relationships between the occurrence of complications and age, sex, Garden stage, bone mineral density (BMD), history of contralateral hip fracture, and any additional hip injury.

RESULTS

Major complications occurred in 18 cases (34.6 %), including nonunion (8 cases), osteonecrosis (6 cases), stress fracture of the subtrochanter (2 cases), excessive pull-out of a screw (1 case), and deep infection (1 case). The development of complications was associated with Garden stage 2, BMD, and additional hip injury. However, other factors were not associated with complications. Reoperations were performed in 16 cases (30.1 %), and 2 of the patients died during follow-up.

CONCLUSION

A relatively high rate of complications or reoperations developed after treatment of Garden 2 femoral neck fractures in senile patients >70 years of age with osteoporosis. Although internal fixation has been recommended in the literature for undisplaced femoral neck fractures, primary arthroplasty may be a better option for treatment of Garden type 2 fractures in elderly patients.

Is hexagonal boron nitride always good as a substrate for carbon nanotube-based devices?

Hexagonal boron nitride sheets have been noted especially for their enhanced properties as substrates for sp(2) carbon-based nanodevices. To evaluate whether such enhanced properties would be retained under various realistic conditions, we investigate the structural and electronic properties of semiconducting carbon nanotubes on perfect and defective hexagonal boron nitride sheets under an external electric field as well as with a metal impurity, using density functional theory. We verify that the use of a perfect hexagonal boron nitride sheet as a substrate indeed improves the device performances of carbon nanotubes, compared with the use of conventional substrates such as SiO2. We further show that even the hexagonal boron nitride with some defects can show better performance as a substrate. Our calculations, on the other hand, also suggest that some defective boron nitride layers with a monovacancy and a nickel impurity could bring about poor device behavior since the imperfections impair electrical conductivity due to residual scattering under an applied electric field.

A pilot study on the safety and efficacy of generic mycophenolate agent as conversion maintenance therapy in stable liver transplant recipients

PURPOSE

The patent covering mycophenolate mofetil (MMF) in Korea has expired and, thus, several generic MMF agents are now commercially available. The supply of Cellcept (Roche Korea) was interrupted at the end of 2011, so it was inevitable that a generic MMF would be used instead. During this period, we performed a prospective pilot study to examine the safety and efficacy of a generic mycophenolate agent (Myconol: Hanmi Pharmaceutical, Seoul Korea) for use as conversion maintenance therapy in stable liver transplantation (OLT) recipients.

METHODS

OLT recipients, who were treated with MMF on an outpatient basis from January 2012 to March 2012, attended follow-up interviews conducted. The patients had undergone OLT ≥ 2 years before the study, had tolerated Cellcept, and showed stable liver function. Fifty-three patients were followed up for more than 3 months after conversion to the same dose of Myconol.

RESULTS

After conversion to Myconol, 6 patients (11.3%) experienced new side effects, which disappeared when they reverted to Cellcept (n = 5) or stopped taking Myconol medication (n = 1). The side effects associated with Myconol included gastrointestinal symptoms (indigestion and diarrhea; n = 3), skin eruptions (n = 1), pruritus (n = 1), and insomnia (n = 1). The mean mycophenolic acid levels were 1.71 ± 0.88 μg/mL for Cellcept and 1.83 ± 0.91 μg/mL for Myconol, which showed a strong correlation (r(2) = 0.92, P < .001).

CONCLUSIONS

Myconol showed similar pharmacokinetics to those of Celcept, but a small proportion of patients experienced agent-specific side effects; therefore, patients should be closely monitored when taking Myconol. Also, further studies, with a greater number of patients, are required to identify the full spectrum of drug-associated side effects.

First report: Robotic pelvic exenteration for locally advanced rectal cancer

AIM

The aim of this study was to present the feasibility and surgical outcome of robotic en bloc resection of the rectum and with prostate and seminal vesicle invaded by rectal cancer.

METHOD

The details of three consecutive cases involving male patients in their forties, with locally invasive low rectal cancers are presented. The da Vinci robotic system was used by experienced colorectal and urological surgeons to perform en bloc resection of the rectum, prostate and seminal vesicles.

RESULTS

In the first case, coloanal and vesico-urethral anastomoses were performed, and the second included an end colostomy and vesico-urethral anastomosis. The bladder and bulbar urethra were also removed en bloc in the third case, with robotic intracorporeal ileal conduit formation and end colostomy. There was no major complication postoperatively. In the second patient there was a minor leakage at the vesico-urethral anastomosis. The third was readmitted the following week with a urinary infection which settled with intravenous antibiotics. In the first case, the circumferential resection margin was microscopically positive but the patient is currently free of recurrence after 14 months. In the second and third cases, all margins were clear.

CONCLUSION

This the first report of the use of the da Vinci robotic system for pelvic exenteration in patients with locally advanced rectal cancer invading the prostate and seminal vesicles. The robot may have a potential role in selected patients requiring exenterative pelvic surgery particularly in men.

Geographic information system-coupling sediment delivery distributed modeling based on observed data

Spatially distributed sediment delivery (SEDD) models are of great interest in estimating the expected effect of changes on soil erosion and sediment yield. However, they can only be applied if the model can be calibrated using observed data. This paper presents a geographic information system (GIS)-based method to calculate the sediment discharge from basins to coastal areas. For this, an SEDD model, with a sediment rating curve method based on observed data, is proposed and validated. The model proposed here has been developed using the combined application of the revised universal soil loss equation (RUSLE) and a spatially distributed sediment delivery ratio, within Model Builder of ArcGIS's software. The model focuses on spatial variability and is useful for estimating the spatial patterns of soil loss and sediment discharge. The model consists of two modules, a soil erosion prediction component and a sediment delivery model. The integrated approach allows for relatively practical and cost-effective estimation of spatially distributed soil erosion and sediment delivery, for gauged or ungauged basins. This paper provides the first attempt at estimating sediment delivery ratio based on observed data in the monsoon region of Korea.

Abstract P5-07-07: Prognostic value of mutant TP53 in basal breast cancer

Backgrounds; p53 is a tumor suppressor gene that plays an important role in cell cycle control and apoptosis. In the breast cancer, mutant tumor protein (TP53) is expressed in approximately 30% and patients with mutant TP53 often tend to have poor response to chemotherapy and poor prognosis than those with normal TP53. But, according to a recent study, TP53 inactivation could cause to significant DNA damage and to eventual cell death by mitotic catastrophe. We investigated the expression frequency and prognostic value of mutant TP53 using tissue microarrays of 898 invasive breast cancers.

Patients and methods; From January 1995 to December 2005 at Yeungnam university hospital, patients who diagnosed with the primary invasive breast cancer and received operation were included in this study. Patients with bilateral breast cancer or distant metastasis at the time of diagnosis were excluded. According to the immunohistochemical results of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor 2 (HER2), Ki67, epidermal growth factor (EGFR) and cytokeratin (CK) 5/6, we classified patients into 6 subgroups, luminal A, luminal B1, B2, HER2-enriched, normal breast-like (triple negative nonbasal) and basal-like breast cancers. Immunohistochemical staining for TP53 was performed and we defined more than 10% stain of tumor cell as mutant TP53-positive. Distribution and prognostic significance of mutant TP53 in each subgroup was investigated.

Results; In 898 invasive breast cancers, mutant TP53 was identified in 33.5% (301/898). Each expression frequency of mutant TP53 was 10.9% (42/385) in luminal A, 32.1% (45/140) in luminal B1, 50.0% (34/68) in luminal B2, 63.7% (72/113) in HER2-enriched, 54.7% (35/64) in normal breast-like and 57.0% (73/128) in basal-like subtype, respectively. In whole breast cancer patients, patients with mutant TP53 tended to have poor overall survival (OS) and disease free survival (DFS). However, there was no statistical significance (p = 0.187 and p = 0.651). But, in 128 patients with basal-like breast cancer, mutant TP53 showed good prognosis in both OS and DFS (p = 0.003 and p = 0.021). In basal-like breast cancer, the expression of mutant TP53 had no association with other clinicopathologic factors such as tumor size, lymph node metastasis, histological grade, lymphovascular invasion etc. and 98.4% (126/128) patients received adjuvant chemotherapy. In multivariate anaylsis, expression of mutant TP53 was an independent prognostic factor for OS and DFS in basal-like breast cancers (p = 0.008 and p = 0.012).

Conclusions: This study showed that basal-like breast cancer with mutant TP53 has a good outcome in both OS and DFS. Further studies are needed to identify the action mechanism of mutant TP53.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-07-07.

Perihilar branching patterns of renal artery and extrarenal length of arterial branches and tumour-feeding arteries on multidetector CT angiography

OBJECTIVE

The purpose of our study was to assess the extrarenal length of renal arterial branches and tumour-feeding arteries on multidetector CT (MDCT) angiography, in addition to the perihilar branching patterns, with relevance to segmental artery clamping.

METHODS

MDCT angiograms of 64 patients with renal masses <4 cm were retrospectively reviewed by 2 radiologists. The perihilar branching patterns of the single main renal artery were assessed according to the number of pre-segmental and segmental arteries. The extrarenal lengths of segmental plus pre-segmental arteries and the tumour-feeding arteries, measured on volume-rendered images, were compared according to the vascular segmentation and the tumour location, respectively.

RESULTS

In the 116 kidneys, 1 pre-segmental plus 5 segmental arteries (n=48) was the most common branching pattern. The mean extrarenal length of the inferior segmental plus pre-segmental arteries (33.05 mm) and the posterior segmental plus pre-segmental arteries (32.30 mm) was longer than any of the other segmental plus pre-segmental arteries (apical, 23.87 mm; superior, 26.80 mm; middle, 29.23 mm) (p<0.05). The mean extrarenal length of the lower pole tumour-feeding arteries (35.94 mm) was longer than those of the upper and mid-pole tumour-feeding arteries (24.95 mm, 29.62 mm), with significant difference between the lower and the upper pole tumour-feeding arteries (p<0.05).

CONCLUSION

Tumours in the lower pole, supplied by the inferior or posterior segmental artery, may be more amenable to segmental artery clamping.

ADVANCES IN KNOWLEDGE

MDCT angiography with volume rendering can demonstrate the extrarenal length of tumour-feeding arteries and may help in determining the accessibility for segmental artery clamping.

Estimating the GIS-based soil loss and sediment delivery ratio to the sea for four major basins in South Korea

This paper describes a sediment delivery ratio (SDR) using the Geographic Information System (GIS)-based Revised Universal Soil Loss Equation (RUSLE), to calculate the soil loss and sediment rating curve (SRC) basis of measured data in the six basins of Four Rivers, South Korea. The data set for calculating SDR was prepared during 3 years from 2008 to 2010. Mean soil loss in the six basins of Four Rivers was 515-869 t km(-2) yr(-1) and mean specific sediment yield (SSY) was 20-208 t km(-2) yr(-1) with basin size. The SDR ranged from 0.03 to 0.33 in the six rivers. Most sediment flows in the monsoon period from June to September (mean Max.: >97%; mean Min.: >84%), but SDR is lower than those of similar continental river basins. This is due to environmental factors, for example rainfall characteristics and associated run-off, soil characteristics and cultivated patterns with increasing basin size. This research provides the first application of SDR based on the observed field data in South Korea.

Abstract P5-04-07: Epithelial-mesenchymal transition phenotype in breast cancers is associated with clinicopathologic factors indicating aggressive biologic behavior and poor clinical outcome

Epithelial-mesenchymal transition (EMT) is defined by the loss of epithelial characteristics and the acquisition of a mesenchymal phenotype. EMT in epithelial tumors is a reversible process and expected to be involved in invasion, metastasis and chemoresistance of cancer cells. EMT-inducing factors down-regulate E-cadherin and up-regulate extracellular matrix proteins such as fibronectin. Cancer tissue may display a wide spectrum of expression phenotypes of EMT-related proteins. However, little is known about the clinical significance of the different EMT phenotypes in breast cancers. We investigated expression pattern of EMT-related proteins, E-cadherin and fibronectin in 1,498 invasive breast carcinomas by using immunohistochemistry on tissue microarrays. EMT phenotypes were divided into complete type (E-cadherin-negative and fibronectin-positive); incomplete type, including hybrid (E-cadherin-positive and fibronectin-positive) and null (E-cadherin-negative and fibronectin-negative) types; and a wild type (E-cadherin-positive and fibronectin-negative). We correlated EMT phenotype with clinicopathologic characteristics and patients survival. Loss of E-cadherin was observed in 140 (9.3%) cases and fibronectin was expressed in cancer cells of 320 (21.4%) cases. Twenty three (1.5%) cases were categorized as complete type, 414 (27.6%) as incomplete type (hybrid type, 297; null type, 117), and 1,061 (70.8%) as wild type. Complete EMT phenotype was significantly associated with advanced pT stage, lymph node metastasis, high histological grade, and triple negativity (p &lt; 0.001). Overall survival and disease-free survival rates were significantly worse in the complete type, better in the incomplete type and best in the wild type (p = 0.002 and p &lt; 0.001, respectively). In multivariate Cox proportional hazard model analysis, the complete EMT phenotype was not an independent prognostic factor for both overall and disease-free survival. In conclusion, breast cancer patients with EMT phenotype showed less favorable outcomes than those with wild type as it was strongly associated with clinicopathologic factors indicating aggressive biologic behavior.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-04-07.

The relaxant effect of ginseng saponin on the bladder and prostatic urethra: an in vitro and in vivo study

AIM

To assess the effects of ginseng saponin on relaxation of the bladder and prostatic urethra and to determine its mechanism of action.

MATERIALS AND METHODS

For the in vitro study, prostatic urethra muscle strips were harvested from 18 male New Zealand rabbits. The strips were mounted in organ baths and connected to force displacement transducers. After stabilization, maximal tissue contractions were obtained by the application of phenylepinephrine to the urethra strips, and a dose-response curve for ginseng saponin was constructed (10(-6)-10(-2)M). After pretreatment of urethra strips with N-nitro-L-arginine methyl ester (L-NAME), another dose-response curve for ginseng saponin was constructed. For the in vivo study, we used adult male Sprague-Dawley rats divided into three groups [control, partial bladder outlet obstruction (PBOO) and saponin-fed groups], and we monitored the vesical pressure (P(ves)) and urethral perfusion pressure (UPP).

RESULTS

The ginseng saponin induced a significant dose-dependent relaxant effect on the prostatic urethra strips. A significant relaxant effect of ginseng saponin was observed from 10(-3)M, and ginseng saponin significantly relaxed urethra strips by 50.2 ± 20.26% at 10(-2)M. The relaxant effect was partially inhibited with L-NAME pretreatment. In the in vivo study, the change in UPP between baseline and relaxation was significantly higher in the saponin group than in the control or PBOO group (p < 0.001). The saponin group showed a significantly lower baseline P(ves) than the PBOO group.

CONCLUSIONS

We observed a significant relaxation effect of ginseng saponin on the bladder and prostatic urethra in both in vitro and in vivo studies. The mechanism by which ginseng saponin induces relaxation appears to involve the nitric oxide/nitric oxide synthase pathway.

Adsorption properties of chalcogen atoms on a golden buckyball Au16(-) from first principles

Using first-principles density functional theory, we investigate the adsorption properties of chalcogen elements (oxygen and sulfur) on an anionic golden nanocage Au(16)(-) and its effects on the structural and electronic properties of the golden cage. In particular, we find that when a sulfur atom is encapsulated inside Au(16)(-), its bonding character with Au atoms appears ionic due to electron transfer from sulfur to the gold nanocage. In contrast, the exohedrally adsorbed S atom tends to have strong orbital hybridization with the golden nanocage. For an oxygen adsorption case, electrons from the golden cage tend to be shared with the adsorbed O atom exhibiting strong orbital hybridization, regardless of its adsorption sites. To investigate the transition behaviors between the most stable exohedral and endohedral adsorption configurations, we calculate the activation and reaction energies in the transition. The oxygen atom experiences a lower energy barrier than the sulfur atom due to its smaller atomic radius. Finally, we explore the vibrational properties of S- or O-adsorbed Au(16)(-) buckyballs by calculating their infrared spectra.

P3-04-04: Patterns of Distant Metastasis According to the Molecular Subtypes of Breast Cancer; Results of 529 Breast Cancer Patients

Backgrounds; Distant metastasis from breast cancer arises from various sites. But few studies concerning factors that can predict metastasis patterns in breast cancer has been reported. In this study, we analyzed the effect of breast cancer molecular subtypes on distant metastasis patterns and tried to determine factors that predict metastasis sites.

Patients and methods; From January 1995 to January 2004 at Yeungnam university hospital, patients diagnosed with the primary invasive breast cancer and received treatments were included in this study. Patients with bilateral breast cancer or distant metastasis at diagnosis were excluded. After analyzing estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor 2 (HER2), epidermal growth factor (EGFR) and cytokeratin (CK) 5/6 status, we classified patients into 5 categories, luminal A, luminal B, HER2−enriched, basal-like, and normal (triple negative nonbasal) breast cancers. Distant metastatic patterns of each category were analyzed.

Results; 529 patients were eligible for tissue microassay analysis and median follow-up period was 7.7 years. In this period, total 82 patients (15.5%) had locoregional relapse or distant metastasis and distant metastasis were identified in 54 patients (10.2%). Each distant metastatic rate was 10.5% (33/313) in luminal A, 8.7% (4/46) in luminal B, 10.2% (6/59) in HER2−enriched, 7.9% (7/89) in basal-like, and 18.2% (4/22) in normal subtype. Most frequent site of distant metastasis in all patients was bone and such result was consistent with Luminal A subtype. Liver metastasis was most frequent in Luminal B subtype, lung metastasis in HER2 enriched and normal subtype and brain metastasis in basal-like subtype.

P3-07-16: The Efficacy of Arm Node Preserving Surgery Using Axillary Reverse Mapping for Preventing Lymphedema in Patients with Breast Cancer

Background

Lymphedema affects over 20% of breast cancer patients undergoing axillary dissection. Axillary reverse mapping (ARM) technique to identify and preserve arm node during sentinel lymph node biopsy (SLNB) or axillary lymph node dissection (ALND) was developed to prevent lymphedema. The purpose of this study was to investigate the location and the metastatic rate of the arm node, and finally to evaluate the short term incidence of lymphedema after arm node preserving surgery.

Patients and Methods

From January 2009 to October 2010, 97 breast cancer patients who underwent ARM were enrolled. 2.5ml blue dye was injected in ipsilateral upper inner arm. After at least 20 minutes after injection, SLNB or ALND was performed in the usual manner and blue stained arm nodes and/or lymphatics were identified. We checked arm circumference at baseline and average of 8.8 months after operation in ALND cases and 13.7 months in SLNB cases. Patients were divided into two groups, arm node preserved group (70 patients in ALND, 10 patients in SLNB) and unpreserved group (13 patients in ALND, 4 patients in SLNB). The difference of arm circumference between preoperative and postoperative was checked in these groups.

Results: The mean number of identified blue stained arm nodes was 1.4±0.6. The arm nodes were found in the inferolateral side of axillary and thoracodorsal vessels in 57 patients (58.76%), the inferomedial side in 37 patients (38.14%), the superolateral side in 2 patients (2.06%), and the superomedial side in 1 patient (1.04%). In the majority of patients (92%), arm nodes were located between the lower level of the axillary vein and just below the second intercostal brachial nerve.

In arm node unpreserved group, 2 patients had metastasis in their arm node. The one had a common pathway between the arm node and the sentinel lymph node. Another did not have a common pathway, but had extranodal extension with N3 metastasis. Among ALND patients, in arm node preserved group, the difference of arm circumference between preoperative and postoperative in ipsilateral and contralateral arm was 0.27cm and 0.07cm, respectively, whereas 0.47cm and −0.03cm in unpreserved group, and one lymphedema was found after 6 months. No difference was found between arm node preserved and unpreserved group amoung SLNB patients (0.21cm and 0.39cm in in preserved group, 0.2cm and 0.02cm in unpreserved group).

Silencing of the GnRH type 1 receptor blocks the antiproliferative effect of the GnRH agonist, leuprolide, on the androgen-independent prostate cancer cell line DU145

This study investigated the mechanism of action of a gonadotropin-releasing hormone (GnRH) agonist, leuprolide, on proliferation of the hormone-refractory prostate cancer cell line DU145, transfected with short hairpin RNA (shRNA), to reduce expression of the GNRHR1 gene (which encodes the GnRH type 1 receptor). DU145 cell proliferation in the presence of leuprolide (10(-9) and 10(-7) M) or control medium was measured before and after GnRHR1 knockdown. Reverse transcription-polymerase chain reaction and Western blot analysis were used to measure the degree of GNRHR1 silencing. DU145 cells treated with leuprolide (10(-9) and 10(-7) M) showed significant growth inhibition compared with control-treated DU145 cells. Transfection with GNRHR1 -shRNA significantly decreased GNRHR1 expression at 48 h. DU145 cells transfected with silencing GNRHR1 -shRNA showed normal growth patterns; however, there was no significant inhibition of proliferation of DU145 cells transfected with GNRHR1 -shRNA compared with cells transfected with control-shRNA in response to leuprolide. These data demonstrated that the antiproliferative effect of leuprolide was mediated by the GnRHR1.

Elevated levels of macrophage migration inhibitory factor in women with metabolic syndrome

Metabolic syndrome is a complex clinical disorder characterized by obesity, a disturbance of glucose metabolism, dyslipidemia, and hypertension, leading to increased cardiovascular risk. Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine produced both by innate immune cells and by adipocytes, and it plays an important role in inflammatory and cardiovascular diseases. The goal of this study was to evaluate the expression of circulating MIF in patients with metabolic syndrome. A study was conducted involving 172 persons who attended the Jeju National University Hospital Health Promotion Center. Among the 172 subjects, 88 patients with metabolic syndrome and 84 healthy control subjects were included. Serum MIF levels were considerably higher in patients with metabolic syndrome than in healthy subjects (mean±SEM, 1413.0-pg/ml±102.6 vs. 1077.0-pg/ml±-91.3, p=0.016). Among the metabolic syndrome patients, MIF levels were significantly increased in women (1403.0-pg/ml±114.2 vs. 921.3 pg/ml±117.3, p=0.005), but not in men. Even after further linear regression adjustment for age and body mass index, the expression of MIF for women with metabolic syndrome was still clearly elevated when compared to healthy subjects (p=0.011). Circulating MIF concentrations showed a gender disparity between healthy and metabolic syndrome subjects. An elevation of systemic MIF in women with metabolic syndrome may contribute to pathogenesis of metabolic syndrome or to the development of metabolic syndrome-related diseases, such as atherosclerosis and type 2 diabetes mellitus.