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.

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.

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.

The Prognostic Nutritional Index Predicts Survival and Identifies Aggressiveness of Gastric Cancer.

Nutritional status has been associated with long-term outcomes in cancer patients. The prognostic nutritional index (PNI) is calculated by serum albumin concentration and absolute lymphocyte count, and it may be a surrogate biomarker for nutritional status and possibly predicts overall survival (OS) of gastric cancer. We evaluated the value of the PNI as a predictor for disease-free survival (DFS) in addition to OS in a cohort of 314 gastric cancer patients who underwent curative surgical resection. There were 77 patients in PNI-low group (PNI ≤ 47.3) and 237 patients in PNI-high group (PNI > 47.3). With a median follow-up of 36.5 mo, 5-yr DFS rates in PNI-low group and PNI-high group were 63.5% and 83.6% and 5-yr OS rates in PNI-low group and PNI-high group were 63.5% and 88.4%, respectively (DFS, P < 0.0001; OS, P < 0.0001). In the multivariate analysis, the only predictors for DFS were PNI, tumor-node-metastasis (TNM) stage, and perineural invasion, whereas the only predictors for OS were PNI, age, TNM stage, and perineural invasion. In addition, the PNI was independent of various inflammatory markers. In conclusion, the PNI is an independent prognostic factor for both DFS and OS, and provides additional prognostic information beyond pathologic parameters.

Organic nonvolatile resistive switching memory based on molecularly entrapped fullerene derivative within a diblock copolymer nanostructure.

Organic nonvolatile resistive switching memory is developed via selective incorporation of fullerene derivatives, [6,6]-phenyl-C61 butyric acid methyl ester (PCBM), into the nanostructure of self-assembled poly(styrene-b-methyl methacrylate) (PS10 -b-PMMA130) diblock copolymer. PS10 -b-PMMA130 diblock copolymer provides a spatially ordered nanotemplate with a 10-nm PS nanosphere domain surrounded by a PMMA matrix. Spin casting of the blend solution of PS10 -b-PMMA130 and PCBM spontaneously forms smooth films without PCBM aggregation in which PCBM molecules are incorporated within a PS nanosphere domain of PS10 -b-PMMA130 nanostructure by preferential intermixing propensity of PCBM and PS. Based on the well-defined PS10-b-PMMA 130/PCBM nanostructure, resistive random access memory (ReRAM) exhibits significantly improved bipolar-switching behavior with stable and reproducible properties at low operating voltages (RESET at 1.3 V and SET at -1.5 V) under ambient conditions. Finally, flexible memory devices are achieved using a nanostructured PS10 -b-PMMA130 /PCBM composite in which no significant degradation of electrical properties is observed before and after bending.

In situ heating transmission electron microscopy observation of nanoeutectic lamellar structure in Sn-Ag-Cu alloy on Au under-bump metallization.

We investigated the microstructural evolution of Sn(96.4)Ag(2.8)Cu(0.8) solder through in situ heating transmission electron microscopy observations. As-soldered bump consisted of seven layers, containing the nanoeutectic lamella structure of AuSn and Au5Sn phases, and the polygonal grains of AuSn2 and AuSn4, on Au-plated Cu bond pads. Here, we found that there are two nanoeutectic lamellar layers with lamella spacing of 40 and 250 nm. By in situ heating above 140°C, the nanoeutectic lamella of AuSn and Au5Sn was decomposed with structural degradation by sphering and coarsening processes of the lamellar interface. At the third layer neighboring to the lamella layer, on the other hand, Au5Sn particles with a zig-zag shape in AuSn matrix became spherical and were finally dissipated in order to minimize the interface energy between two phases. In the other layers except both lamella layers, polycrystal grains of AuSn2 and AuSn4 grew by normal grain growth during in situ heating. The high interface energy of nanoeutectic lamella and polygonal nanograins, which are formed by rapid solidification, acted as a principal driving force on the microstructural change during the in situ heating.

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.

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.

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).

Survival benefit of gastrectomy ± metastasectomy in patients with metastatic gastric cancer receiving chemotherapy.

BACKGROUND: This study was performed to investigate the role of surgery in patients with gastric cancer and distant metastases who had received systemic chemotherapy. METHODS: Patients with newly diagnosed gastric cancer and synchronous distant metastases who had received chemotherapy (n = 274) were categorized into 3 groups according to the surgical treatment rendered: complete gross resection of both primary and metastatic sites (group A; n = 42); debulking gastrectomy (group B; n = 47); and chemotherapy without debulking (group C; n = 185). RESULTS: The median overall survival of all patients was 11.8 months. The median overall survival and 3-year survival rates were 28.0, 15.5, and 9.0 months and 42.8, 8.1, and 3.5% in groups A, B, and C, respectively. In group A, patients with peritoneal seeding, intra-abdominal distant lymph nodes, or ovarian or hepatic metastases underwent complete gross resection, and 12 (29%) were disease-free at the time of the last analysis (median follow-up duration, 29.1 months). On multivariate analysis, the adjusted hazard ratios for death were 0.27 (P < 0.001) and 0.64 (P = 0.024) for groups A and B, respectively, as compared to group C. CONCLUSIONS: Our study suggests survival benefits of debulking gastrectomy or gastrectomy plus metastasectomy in gastric cancer patients with distant metastases receiving systemic chemotherapy. Prolonged disease-free survival was observed after complete resection (gastrectomy plus metastasectomy) that may lead to cure in some patients. Well-designed prospective trials of the role of multidisciplinary approaches combining chemotherapy and surgery are needed to confirm the observations of our study.

Discordant human epidermal growth factor receptor 2 and hormone receptor status in primary and metastatic breast cancer and response to trastuzumab.

BACKGROUND: Recent studies have shown that the human epidermal growth factor receptor 2 status of a metastatic site may differ from that of the primary site. This difference may influence patient prognosis and response to therapy. METHODS: We conducted a retrospective study using immunohistochemistry and/or fluorescent in situ hybridization to compare human epidermal growth factor receptor 2 and hormone receptor status in primary and metastatic breast cancers. RESULTS: Fifty-six patients were included in this study. Conversion from hormone receptor positive in the primary tumor to hormone receptor negative in the metastasis occurred in 12 patients (21.4%), and hormone receptor negative to hormone receptor positive conversion occurred in two patients (3.6%). Human epidermal growth factor receptor 2 status was discordant between primary and metastatic lesions in seven patients (12.5%). All of the five patients who converted from human epidermal growth factor receptor 2 negative status to human epidermal growth factor receptor positive received trastuzumab-based chemotherapy. Overall response rate and median progression-free survival for concordant human epidermal growth factor receptor 2 positive patients were 69.2% and 16.9 months, whereas that of patients with positive conversion of human epidermal growth factor receptor 2 were 40.0% and 7.6 months, respectively (overall response rate; P = 0.169 and progression-free survival; P = 0.004). CONCLUSION: Discordance in human epidermal growth factor receptor 2 and hormone receptor status between primary and metastatic tumors was observed, which led to altered treatment decisions. Evaluation of human epidermal growth factor receptor 2 and hormone receptor in metastatic tumors should be considered in patients with breast cancer.

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.

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.

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.

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.

A case of Wernicke's encephalopathy following fluorouracil-based chemotherapy.

The pyrimidine antimetabolite 5-fluorouracil (5-FU) is a chemotherapeutic agent used widely for various tumors. Common side effects of 5-FU are related to its effects on the bone marrow and gastrointestinal epithelium. Neurotoxicity caused by 5-FU is uncommon, although acute and delayed forms have been reported. Wernicke's encephalopathy is an acute, neuropsychiatric syndrome resulting from thiamine deficiency, and has significant morbidity and mortality. Central nervous system neurotoxicity such as Wernicke's encephalopathy following chemotherapy with 5-FU has been reported rarely, although it has been suggested that 5-FU can produce adverse neurological effects by causing thiamine deficiency. We report a patient with Wernicke's encephalopathy, reversible with thiamine therapy, associated with 5-FU-based chemotherapy.

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.

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.

Prognostic significance of CD44s expression in biliary tract cancers.

BACKGROUND: CD44 is an essential surface glycoprotein component of the hyaluronan receptor and is associated with adhesion and metastasis in many solid tumors. There are several isoforms of CD44, including CD44 standard (CD44s) and 10 CD44 variants (CD44v1 to CD44v10). We evaluated the clinical significance of CD44s and CD44v6 in biliary tract cancers. METHODS: Patients who had been diagnosed with primary biliary tract cancers were enrolled onto the study, and tissue specimens were obtained during surgery. Paraffin-embedded tissue sections were evaluated for the presence of CD44s and CD44v6 by immunohistochemical staining. We decided CD44s and CD44v6 expression as overexpression, which shows an intensity grade of >10%. Clinical data of all patients were reviewed. RESULTS: Ninety-five patients (35 men and 60 women; median age, 64 years; range, 37-86 years) were evaluated. The incidence of overexpression (>10%) of CD44s was 49%, and that of CD44v6 was 17%. The median postoperative follow-up duration was 34.3 months, and the median overall survival was 12.2 months. The Cox proportional hazard ratio (HR) test identified CD44s overexpression (0% to 10% vs. 10% to 100%; HR, .420; 95% confidence interval [95% CI], .211-.837; P = .014) and cancer stage as prognostic factors. However, the expression of CD44v6 (0% to 10% vs. 10% to 100%; HR, 1.462; 95% CI, .630-3.393; P = .377) had no prognostic significance for survival. CONCLUSIONS: CD44s overexpression is useful as a marker of a poor prognosis for biliary tract cancer. Aggressive postoperative therapy should be considered for such patients.