Size-dependent deformation behavior in nanosized amorphous metals suggesting transition from collective to individual atomic transport.

The underlying atomistic mechanism of deformation is a central problem in mechanics and materials science. Whereas deformation of crystalline metals is fundamentally understood, the understanding of deformation of amorphous metals lacks behind, particularly identifying the involved temporal and spatial scales. Here, we reveal that at small scales the size-dependent deformation behavior of amorphous metals significantly deviates from homogeneous flow, exhibiting increasing deformation rate with reducing size and gradually shifted composition. This transition suggests the deformation mechanism changes from collective atomic transport by viscous flow to individual atomic transport through interface diffusion. The critical length scale of the transition is temperature dependent, exhibiting a maximum at the glass transition. While viscous flow does not discriminate among alloy constituents, diffusion does and the constituent element with higher diffusivity deforms faster. Our findings yield insights into nano-mechanics and glass physics and may suggest alternative processing methods to epitaxially grow metallic glasses.

Voltage control of magnetism in Fe3-xGeTe2/In2Se3 van der Waals ferromagnetic/ferroelectric heterostructures.

We investigate the voltage control of magnetism in a van der Waals (vdW) heterostructure device consisting of two distinct vdW materials, the ferromagnetic Fe3-xGeTe2 and the ferroelectric In2Se3. It is observed that gate voltages applied to the Fe3-xGeTe2/In2Se3 heterostructure device modulate the magnetic properties of Fe3-xGeTe2 with significant decrease in coercive field for both positive and negative voltages. Raman spectroscopy on the heterostructure device shows voltage-dependent increase in the in-plane In2Se3 and Fe3-xGeTe2 lattice constants for both voltage polarities. Thus, the voltage-dependent decrease in the Fe3-xGeTe2 coercive field, regardless of the gate voltage polarity, can be attributed to the presence of in-plane tensile strain. This is supported by density functional theory calculations showing tensile-strain-induced reduction of the magnetocrystalline anisotropy, which in turn decreases the coercive field. Our results demonstrate an effective method to realize low-power voltage-controlled vdW spintronic devices utilizing the magnetoelectric effect in vdW ferromagnetic/ferroelectric heterostructures.

Mechanically derived short-range order and its impact on the multi-principal-element alloys.

Chemical short-range order in disordered solid solutions often emerges with specific heat treatments. Unlike thermally activated ordering, mechanically derived short-range order (MSRO) in a multi-principal-element Fe40Mn40Cr10Co10 (at%) alloy originates from tensile deformation at 77 K, and its degree/extent can be tailored by adjusting the loading rates under quasistatic conditions. The mechanical response and multi-length-scale characterisation pointed to the minor contribution of MSRO formation to yield strength, mechanical twinning, and deformation-induced displacive transformation. Scanning and high-resolution transmission electron microscopy and the anlaysis of electron diffraction patterns revealed the microstructural features responsible for MSRO and the dependence of the ordering degree/extent on the applied strain rates. Here, we show that underpinned by molecular dynamics, MSRO in the alloys with low stacking-fault energies forms when loaded at 77 K, and these systems that offer different perspectives on the process of strain-induced ordering transition are driven by crystalline lattice defects (dislocations and stacking faults).

Electron-beam induced damage process for Ca2Na2Nb5O16nanosheets.

Dielectric two-dimensional oxide nanosheets are attractive because of their thermal stability and high-k property. However, their atomic structure characterization has been limited since they are easily degraded by electron-beams. This study aimed to investigate the electron-beam induced damage mechanisms for exfoliated Ca2Na2Nb5O16(CNNO) nanosheets. Knock-on damage dominantly occurred at high voltages, leaving short-range order in the final amorphous structure. On the other hand, a series of chemical reactions predominantly occurred at low voltages, resulting in random elemental loss and a fully disordered amorphous structure. This radiolysis was facilitated by insulated CNNO nanosheets that contained a large number of dangling bonds after the chemical solution process. The radiolysis damage kinetics was faster than knock-on damage and induced more elemental loss. Based on our understanding of the electron beam-induced degradation, atomic-scale imaging of the CNNO nanosheets was successfully performed using Cs-corrected scanning transmission electron microscopy at 300 keV with a decreased beam current. This result is of particular significance because understanding of electron-beam damage in exfoliated and insulating 2D oxide sheets could improve identification of their atomic structure using electron microscopy techniques and lead to a practical guide for further extensive characterization of doped elements and layered structures to improve their properties.

Emergency Department Utilization of Adult Cancer Patient in Korea: A Nationwide Population-Based Study, 2017-2019.

PURPOSE: The current study aimed to identify the overall characteristics of cancer-related emergency department (ED) visits by adult in Korea, including analyses of factors associated with ED stay time and outcomes nationwide. MATERIALS AND METHODS: We collected data on cancer-related ED visits from the National Emergency Department Information System (NEDIS) database between 2017 and 2019. RESULTS: ED visits by cancer patients comprised 5.5% (667,935 visits) of total ED visits from 2017 to 2019, which was slightly higher than in other counties. Patients with cancer who visited the ED were over 50 years old, the majority being males, and patients with cancer visited EDs in certified tertiary hospitals more frequently than patients without cancer. In multivariate analyses, the adjusted odds ratio for a length of stay more than 8 hours in the ED of certified tertiary hospitals was 126.34 (95% confidence interval, 1.422 to 1.460) when compared to hospitals. Nevertheless, the longer the patients stayed in the ED, the more likely they were to be admitted. CONCLUSION: The longer ED stay and higher proportion of cancer patient hospitalizations suggest that cancer patients visit ED to be admitted as well as to receive acute care. The frequency of ED visits and admission may be adjusted to some extent depending on outpatient education, such as self-management of symptoms and situations. Improving cancer care in local communities should be met though provisions such as linking treatment between hospitals or supplying appropriate medical personnel, even for the efficient use of ED resources in hospitals.

Atomically sculptured heart in oxide film using convergent electron beam.

We demonstrate a fabrication of an atomically controlled single-crystal heart-shaped nanostructure using a convergent electron beam in a scanning transmission electron microscope. The delicately controlled e-beam enable epitaxial crystallization of perovskite oxide LaAlO3 grown out of the relative conductive interface (i.e. 2 dimensional electron gas) between amorphous LaAlO3/crystalline SrTiO3.

Exchange Bias in Weakly Interlayer-Coupled van der Waals Magnet Fe3GeTe2.

van der Waals (vdW) magnetic materials provide an ideal platform to study low-dimensional magnetism. However, observations of magnetic characteristics of these layered materials truly distinguishing them from conventional magnetic thin film systems have been mostly lacking. In an effort to investigate magnetic properties unique to vdW magnetic materials, we examine the exchange bias effect, a magnetic phenomenon emerging at the ferromagnetic-antiferromagnetic interface. Exchange bias is observed in the naturally oxidized vdW ferromagnet Fe3GeTe2, owing to an antiferromagnetic ordering in the surface oxide layer. Interestingly, the magnitude and thickness dependence of the effect is unlike those expected in typical thin-film systems. We propose a possible mechanism for this behavior, based on the weak interlayer magnetic coupling inherent to vdW magnets, demonstrating the distinct properties of these materials. Furthermore, the robust and sizable exchange bias for vdW magnets persisting up to relatively high temperatures presents a significant advance for realizing practical two-dimensional spintronics.

A potential treatment option for elderly non-Hodgkin lymphoma patients with multiple comorbidities: Two case reports and literature review.

Non-Hodgkin lymphoma (NHL) is a heterogeneous lymphoproliferative malignancy. More than half of the NHL cases occur in patients over 65 years of age. As elderly patients have a poor performance status and multiple comorbidities, the use of standard chemotherapy is often limited, leading to poor clinical outcomes and an increasing need for an alternate therapeutic modalities. A 73-year-old man was diagnosed with extranodal NK/T-cell lymphoma concurrently combined with recurrent gastric adenocarcinoma and metastatic prostate cancer. A 79-year-old woman was diagnosed with T-cell and B-cell dual-phenotype NHL on the right chest wall showing tumor thrombosis and multiple enlarged lymph nodes under chronic emphysema with extensive pleural calcification. Both elderly patients had multiple comorbidities and pathologically confirmed non-Hodgkin lymphoma. Both patients achieved tumor responses following anticancer treatment with Korean medicine (KM), suggesting that the extracts of Angelica gigas Nakai and Geopungtang are potential options for treating NHL in elderly patients with multiple comorbidities. Considering the clinical outcomes of KM treatment in the two elderly patients with NHL and multiple comorbidities, this study generates a research hypothesis for future prospective clinical studies in patients with NHL who are ineligible for conventional anticancer therapy.

Preoperative plateletcrit is a Prognostic Biomarker for Survival in Patients with Non-Small Cell Lung Cancer.

Objectives: Several factors associated with the prognosis of patients with NSCLC have been reported in the literature; however, most of these factors cannot be examined preoperatively. In this study, the clinical utility of platelet parameters in patients with NSCLC who underwent curative resection was evaluated. Materials and Methods: A retrospective study on patients with NSCLC who underwent curative resection from July 2006 to September 2016 was conducted. The Cox proportional hazard regression model was applied to evaluate the variables that demonstrated effects on disease-free and overall survival (DFS and OS). Results: A total of 116 patients with NSCLC were analyzed. There were 15 patients with plateletcrit greater than 0.2755%, and 101 patients whose plateletcrit was 0.2755% or lower. Multivariate analysis identified plateletcrit higher than 0.2755% (hazard ratio [HR] = 4.18, 95% confidence interval [CI] = 1.54-11.34, P =0.004), patient age of 65 years or more (HR = 4.02, 95% CI = 1.67-9.66, P = 0.001), and stage II or IIIA disease (HR = 2.95, 95% CI = 1.26-6.87, P = 0.012) as independent factors for OS that predicted a poor prognosis. Multivariate analysis identified plateletcrit higher than 0.2755% (HR = 4.07, 95% CI = 1.52-10.94, P = 0.005), stage II or IIIA disease (HR = 5.38, 95% CI = 2.71-10.66, P < 0.001) and non-adenocarcinoma (HR = 1.92, 95% CI = 1.02-3.59, P = 0.040) as independent prognostic factors for DFS that predicted a poor prognosis. Conclusion: Our results suggest a potential role of preoperative plateletcrit as an independent prognostic marker for patients with resectable NSCLC.

Development and Feasibility of a Safety Plan Mobile Application for Adolescent Suicide Attempt Survivors.

Past suicide attempts are a powerful predictor of suicide. This study developed and evaluated the feasibility of a mobile application for creating safety plans, which include coping strategies that can be immediately accessed and used by suicide attempt survivors during a crisis. A safety plan mobile application, called Brake of My Mind, was developed (study 1). Heuristic evaluation (for experts) and user evaluations (for health professionals and adolescent suicide attempt survivors) were performed. A pilot test was then conducted based on the theory of planned behavior to evaluate the feasibility of Brake of My Mind (study 2). Three adolescent suicide attempt survivors used a pilot version of Brake of My Mind. Attitude toward suicide attempts, subjective norms, perceived behavioral control, and suicide intentions were assessed before, immediately after, and 1 week after using Brake of My Mind. Brake of My Mind showed very few low-priority usability problems, and it was considered a "good" and "acceptable" application. In study 2, median scores for attitudes toward suicide attempts, perceived behavioral control, and suicide intentions decreased over time after using Brake of My Mind. The subjective norm scores did not change. Brake of My Mind is an acceptable application for adolescent suicide attempt survivors that appears effective in decreasing their positive attitude toward suicide attempts.

Microscopic analysis of metal matrix composites containing carbon Nanomaterials.

Metallic matrix composites reinforced with carbon nanomaterials continue to attract interest because of their excellent mechanical, thermal, and electrical properties. However, two critical issues have limited their commercialization. Uniform distribution of carbon nanomaterials in metallic matrices is difficult, and the interfaces between the nanomaterials and matrices are weak. Microscope-based analysis was recently used to quantitatively examine these microstructural features and investigate their contributions to the composites' mechanical, thermal, and electrical properties. The impacts of the microstructure on these properties are discussed in the first section of this review. In the second section, the various microscopic techniques used to study the distribution of carbon nanomaterials in metallic matrices and their interfaces are described.

Influence of combinatory effects of STEM setups on the sensitivity of differential phase contrast imaging.

Differential phase-contrast (DPC) imaging in the scanning transmission electron microscopy (STEM) mode has been suggested as a new method to visualize the nanoscale electromagnetic features of materials. However, the quality of the DPC image is very sensitive to the electron-beam alignment, microscope setup, and specimen conditions. Unlike normal STEM imaging, the microscope setup variables in the DPC mode are not independent; rather, they are correlated factors decisive for field sensitivity. Here, we systematically investigated the independent and combinatory effects of microscope setups on the sensitivity of the DPC image in a hard magnet, Nd2Fe14B alloy. To improve sensitivity, a smaller overlap of the electron beam with annular detectors and a greater camera length were required. However, these factors cannot be controlled independently in the two-condenser-lens system. In this linked system, the effect of the camera length on the DPC sensitivity was slightly more predominant than the overlap. Furthermore, the DPC signal was noisy and scattered at a small overlap of less than 11%. The electron-beam current does not evidently affect the sensitivity. In addition, the DPC sensitivity was examined with respect to the sample thickness, and the optimum thickness for high sensitivity was approximately 65 nm for the hard magnetic material Nd2Fe14B. This practical approach to the STEM setup and sample thickness may provide experimental guidelines for further application of the DPC analysis method.

Microscale BTS sculptured by electron beam.

We applied the advanced bitmap-assisted patterning function of focused ion beam to fabricate microscale sculpture of the 'BangTanSoNyeonDan' known as BTS members, the world-wide famous K-pop boyband. With the help of an electron microscope, you can carve your idols on your accessories at micro scale. Fun applications of electron microscopes are not limited to science.

Characterization of Cr (VI) - Containing solid phase particles in dry dust deposition in Daejeon, South Korea.

Solid phase speciation of chromium in dry dust deposition and road paint was determined using transmission electron microscopy (TEM) and X-ray absorption spectroscopy (XAS). Spherical black carbon aggregates in dry dust deposition contained discrete nano-sized lead chromate (PbCrO4) and zinc chromate (ZnCrO4), which likely originated from yellow traffic paint and zinc chromate primer (corrosion resistant pigment), respectively based on their main applications. Road marking paint samples from auto roads included lead chromate particles whose size, shape, composition and crystal structure were similar to those in dry dust deposition. A slight difference was found at the particle boundary. Namely, lead chromate in traffic paint was encapsulated by silica-bearing matrix, while discrete lead chromate in the black carbon of dry deposition was rarely enclosed within silica-bearing matrix. The Cr K edge X-ray absorption near edge structure (XANES) spectrum for dry deposition showed the characteristic pre-edge resonance peak similar to the spectra for the Cr(VI) standard and road paint, but the lower intensity. The amount of Cr(VI) accounted for approximately 45% of the total Cr in the dust sample. The solid phase speciation of Cr observed using TEM and their valence states determined using XANES were consistent with the chemical speciation determined using the sequential extraction. The contribution of this study is that XANES was applied to identify Cr valance states in urban dust deposition and zinc chromate was found as a Cr(VI) phase in dry dust deposition using TEM. These study results provide novel data on Cr speciation and Cr(VI)-containing mineral phases in dry dust deposition and their potential sources. Based on the wide use of lead and zinc chromate, atmospheric contamination with these solid phase speciation of Cr(VI) is expected in other cities in the world.

Enhancing Thermoelectric Performances of Bismuth Antimony Telluride via Synergistic Combination of Multiscale Structuring and Band Alignment by FeTe2 Incorporation.

It has been a difficulty to form well-distributed nano- and mesosized inclusions in a Bi2Te3-based matrix and thereby realizing no degradation of carrier mobility at interfaces between matrix and inclusions for high thermoelectric performances. Herein, we successfully synthesize multistructured thermoelectric Bi0.4Sb1.6Te3 materials with Fe-rich nanoprecipitates and sub-micron FeTe2 inclusions by a conventional solid-state reaction followed by melt-spinning and spark plasma sintering that could be a facile preparation method for scale-up production. This study presents a bismuth antimony telluride based thermoelectric material with a multiscale structure whose lattice thermal conductivity is drastically reduced with minimal degradation on its carrier mobility. This is possible because a carefully chosen FeTe2 incorporated in the matrix allows its interfacial valence band with the matrix to be aligned, leading to a significantly improved p-type thermoelectric power factor. Consequently, an impressively high thermoelectric figure of merit ZT of 1.52 is achieved at 396 K for p-type Bi0.4Sb1.6Te3-8 mol % FeTe2, which is a 43% enhancement in ZT compared to the pristine Bi0.4Sb1.6Te3. This work demonstrates not only the effectiveness of multiscale structuring for lowering lattice thermal conductivities, but also the importance of interfacial band alignment between matrix and inclusions for maintaining high carrier mobilities when designing high-performance thermoelectric materials.

Experiences and Opinions Related to End-of-Life Discussion: From Oncologists' and Resident Physicians' Perspectives.

PURPOSE: The aims of this study were to explore how oncologists and resident physicians practice end-of-life (EOL) discussions and to solicit their opinions on EOL discussions as a means to improve the quality of EOL care. MATERIALS AND METHODS: A survey questionnaire was developed to explore the experiences and opinions about EOL discussions among oncologists and residents. Descriptive statistics, the t test, and the chisquare test were performed for the analyses. RESULTS: A total of 147 oncologists and 229 residents participated in this study. The study respondents reported diverse definitions of "terminal state," and mostrespondents tried to disclose the patient's condition to the patient and/or family members. Both groups were involved in EOL care discussions, with a rather low satisfaction level (57.82/100). The best timing to initiate discussionwas consideredwhen metastasis or disease recurrence occurred orwhen withdrawal of chemotherapy was anticipated. Furthermore, the study respondents suggested that patients and their family members should be included in the EOL discussion. Medical, legal, and ethical knowledge and communication difficulties along with practical issues were revealed as barriers and facilitators for EOL discussion. CONCLUSION: This study explored various perspectives of oncologists and resident physicians for EOL discussion. Since the Life-Sustaining-Treatment Decision-Making Act will be implemented shortly in Korea, now is the time for oncologists and residents to prepare themselves by acquiring legal knowledge and communication skills. To achieve this, education, training, and clinical tools for healthcare professionals are required.

Recurrent maxillary sinus cancer with only adrenal metastasis.

Maxillary sinus cancer is rare, and often presents as a locally advanced disease. Recurrence commonly occurs locoregionally, while fewer patients present with distant metastasis; the most common sites involved are the lung and bone. This report discusses the case of a 64-year-old male who presented with a mass in the left submandibular area. Biopsy was performed and histological analysis identified a poorly differentiated squamous cell carcinoma. After staging work up, it was concluded the patient had a maxillary sinus squamous cell carcinoma at clinical stage IVA. The patient received a left partial maxillectomy and left radical neck dissection followed by postoperative chemoradiotherapy. After three months of CRT, the patient developed a left adrenal gland metastasis without locoregional failure. The patient subsequently received a laparoscopic left adrenalectomy and the results of histological analysis revealed a poorly-differentiated squamous cell carcinoma. Within one month of surgery, the patient had developed multiple metastases at the left adrenalectomy site and succumbed to the disease four months later.

Prognostic value of KRAS codon 13 gene mutation for overall survival in colorectal cancer: Direct and indirect comparison meta-analysis.

BACKGROUND: The clinical significance of KRAS codon 13 mutation in patients with colorectal cancer (CRC) remains controversial. A systematic review and meta-analysis is necessary for a more precise estimation of the predictive role of KRAS codon 13 mutations in CRC patients. METHODS: We performed a systematic search using the MEDLINE, EMBASE, and Cochrane library databases from January 2000 to November 2016. The prognostic value of KRAS codon 13 mutation for overall survival (OS) was investigated by measuring the hazard ratio (HR) and 95% confidence interval (CI). Data were analyzed with Review Manager Version 5.3 and the Canadian Agency for Drugs and Technologies in Health software. RESULTS: OS in CRC patients with KRAS codon 13 mutation was worse than that in CRC patients with KRAS wild-type (pooled HR = 1.37, 95% CI: 1.03-1.81, P = .03). Subgroup analysis of studies of enrolled CRC patients treated with antiepidermal growth factor receptor (EGFR) therapy showed no significant difference in OS associated with KRAS codon 13 mutation in comparison to KRAS wild-type (pooled HR = 1.57, 95% CI: 0.98-2.51, P = .06). In the indirect comparison, no statistically significant association was observed between codon 12 and 13 mutations for OS in CRC patients (pooled HR = 0.88, 95% CI: 0.65-1.20, P = .43). CONCLUSION: The current meta-analysis suggests that Codon 13 mutation of KRAS gene seems to correlate with the OS of patients with CRC, but has similar OS to those with KRAS wild-type in patients receiving anti-EGFR therapy. No difference was detected in the OS of CRC patients with codon 13 mutation versus codon 12 mutation.

The Association between End-of-Life Care and the Time Interval between Provision of a Do-Not-Resuscitate Consent and Death in Cancer Patients in Korea.

PURPOSE: We explored the relationship between the use of each medical intervention and the length of time between do-not-resuscitate (DNR) consent and death in Korea. MATERIALS AND METHODS: A total of 295 terminal cancer patients participated in this retrospective study. Invasive interventions (e.g., cardiopulmonary resuscitation, intubation, and hemodialysis), less invasive interventions (e.g., transfusion, antibiotic use, inotropic use, and laboratory tests), and the time interval between the DNR order and death were evaluated. The subjects were divided into three groups based on the amount of time between DNR consent and death (G1, time interval ≤ 1 day; G2, time interval > 1 day to ≤ 3 days; and G3, time interval > 3 days). RESULTS: In general, there were fewer transfusions and laboratory tests near death. Invasive interventions tended to be implemented only in the G1 group. There was also less inotrope use and fewer laboratory tests in the G3 group than G1 and G2. Moreover, the G3 group received fewer less invasive interventions than those in G1 (odds ratio [OR], 0.16; 95% confidence interval [CI], 0.03 to 0.84; 3 days before death, and OR, 0.16; 95% CI, 0.04 to 0.59; the day before death). The frequency of less invasive interventions both 1 and 3 days before death was significantly lower for the G3 group than the G1 (p ≤ 0.001) and G2 group compared to G1 (p=0.001). CONCLUSION: Earlier attainment of DNR permission was associated with reduced use of medical intervention. Thus, physicians should discuss death with terminal cancer patients at the earliest practical time to prevent unnecessary and uncomfortable procedures and reduce health care costs.

Lead chromate detected as a source of atmospheric Pb and Cr (VI) pollution.

Spherical black carbon aggregates were frequently observed in dust dry deposition in Daejeon, Korea. They were tens of micrometers in diameter and presented a mixture of black carbon and several mineral phases. Transmission electron microscopy (TEM) observations with energy-dispersive X-ray spectroscopy (EDS) and selected area diffraction pattern (SADP) analyses confirmed that the aggregates were compact and included significant amounts of lead chromate (PbCrO4). The compositions and morphologies of the nanosized lead chromate particles suggest that they probably originated from traffic paint used in roads and were combined as discrete minerals with black carbon. Based on Pb isotope analysis and air-mass backward trajectories, the dust in Daejeon received a considerable input of anthropogenic pollutants from heavily industrialized Chinese cities, which implies that long-range transported aerosols containing PbCrO4 were a possible source of the lead and hexavalent chromium levels in East Asia. Lead chromate should be considered to be a source of global atmospheric Pb and Cr(VI) pollution, especially given its toxicity.