Resolving hydrogen atoms at metal-metal hydride interfaces

Hydrogen as a fuel can be stored safely with high volumetric density in metals. It can, however, also be detrimental to metals causing embrittlement. Understanding fundamental behavior of hydrogen at atomic scale is key to improve the properties of metal-metal hydride systems. However, currently, there is no robust technique capable of visualizing hydrogen atoms. Here, we demonstrate that hydrogen atoms can be imaged unprecedentedly with integrated differential phase contrast, a recently developed technique performed in a scanning transmission electron microscope. Images of the titanium-titanium monohydride interface reveal remarkable stability of the hydride phase, originating from the interplay between compressive stress and interfacial coherence. We also uncovered, thirty years after three models were proposed, which one describes the position of the hydrogen atoms with respect to the interface. Our work enables novel research on hydrides and is extendable to all materials containing light and heavy elements, including oxides, nitrides, carbides and borides

Clinicopathological and targeted exome gene features of a patient with metastatic acinic cell carcinoma of the parotid gland harboring an ARID2 nonsense mutation and CDKN2A/B deletion

We describe the presentation, treatment, clinical outcome, and targeted genome analysis of a metastatic salivary acinic cell carcinoma (AciCC). A 71-year-old male presented with a 3 cm right tail of a parotid lesion, first detected as a nodule by the patient seven months earlier. He had a right total parotidectomy with cranial nerve VII resection, right facial nerve resection and grafting, resection of the right conchal cartilage, and right modified radical neck dissection. The primary tumor revealed AciCC with two distinct areas: a well-differentiated component with glandular architecture and a dedifferentiated component with infiltrative growth pattern associated with prominent stromal response, necrosis, perineural invasion, and cellular pleomorphism. Tumor staging was pT4 N0 MX. Immunohistochemistry staining showed pankeratin (+), CD56 (−), and a Ki67 proliferation index of 15%. Upon microscopic inspection, 49 local lymph nodes resected during parotidectomy were negative for cancer cells. Targeted sequencing of the primary tumor revealed deletions of CDKN2A and CDKN2B, a nonsense mutation in ARID2, and single missense mutations of unknown significance in nine other genes. Despite postoperative localized radiation treatment, follow-up whole body PET/CT scan showed lung, soft tissue, bone, and liver metastases. The patient expired 9 months after resection of the primary tumor

Pengaruh Profitabilitas, Risiko Keuangan, Nilai Perusahaan, Kepemilikan Manajerial, dan Dividend Payout Ratio terhadap Praktik Perataan Laba (Studi Empiris pada Perusahaan Real Estate dan Properti yang Terdaftar di Bursa Efek Indonesia Tahun 2011-2013)

This study aims to demonstrate the influence of profitability, financial risk, firm value, managerial ownership, and dividend payout ratio toward income smoothing practice done by management. The population in this study is all real estate and property company listed on Indonesian Stock Exchange (IDX). Samples were decided by using purposive sampling method. Samples in this study choose based on several criteria and as much as 35 (thirty five) companies were selected. The methodology used in this is multiple regressions analysis. The results of this study stated that financial risk (LEV) has significant effect to the income smoothing practice of real estate and Property Company listed on Indonesian Stock Exchange year 2011-2013. While the ROA, PBV, MOWN, and DPR have no significant effect to the income smoothing practice of real estate and Property Company listed on Indonesian Stock Exchange in 2011-2013. Coefficient of determination obtained amount to 0,088 or 8,8%. It indicates that income smoothing practices in real estate and Property Company are described by 8,8% by ROA, LEV, PBV, MOWN, and DPR. The remaining of 91,2% are influenced by other factor which were not examined in this study.Keywords: Profitability (ROA), Financial Risk (LEV), Firm Value (PBV), Managerial Ownership (MOWN), Dividend Payout Ratio (DPR), Income Smoothing Practice

Structure and reconfiguration of epitaxial GeTe/Sb2Te3 superlattices

De materialen bestaande uit gemengde GeTe/Sb2Te3 legeringen vertonen opmerkelijk omschakelbare opto-elektronische eigenschappen tussen hun amorfe en kristallijne fasen. Om die reden zijn ze met succes geïmplementeerd in herschrijfbare optische DVD en Blu-Ray schijven en worden ze momenteel intensief onderzocht voor toekomstige geheugen- en fotonische toepassingen. Recentelijk werd aangetoond dat nanostructurering van deze legeringen door GeTe en Sb2Te3 in de vorm van superroosters te laten groeien de prestaties van de resulterende phase-change geheugens aanzienlijk verbetert. Ondanks deze vooruitgang waren de oorsprong van de verbetering en het gedetailleerde schakelmechanisme nog niet begrepen. Vandaar dat de focus van dit proefschrift ligt op de groei en karakterisatie van dergelijke superroosters. Met behulp van voornamelijk transmissie-elektronenmicroscopie is de gedetailleerde kristalstructuur van dergelijke multilagen geanalyseerd en uitgelegd in termen van de elektronische binding van de legeringen. Verschillende schakelmechanismen van superrooster phase-change geheugens in de literatuur werden besproken en het werd aangetoond dat ze inconsistent waren met de feitelijke structuur van de lagen. Bovendien werd aangetoond dat GeTe/Sb2Te3 superroosters een interessant platform kunnen zijn om gemengde GeTe/Sb2Te3 legeringen te bestuderen door in detail de thermische reconfiguratie ervan in kaart te brengen. In de laatste delen van het proefschrift wordt de groei van dunne lagen besproken met speciale aandacht voor de substraat-film interface. Over het algemeen werpen de resultaten licht op de structuur en het schakelmechanisme van GeTe/Sb2Te3 superrooster phase-change geheugens en illustreren paden voor de groei van vergelijkbare materialen voor ferro-elektrische, spintronische en thermo-elektrische toepassingen.The materials based on mixed GeTe/Sb2Te3 alloys show remarkable switchable opto-electronic properties between their amorphous and crystalline phases. They are therefore successfully implemented in rewritable optical DVD and Blu-Ray disks and are currently under intense investigation for future memory and photonic applications. Recently, it was shown that nanostructuring these alloys by growing GeTe and Sb2Te3 in the form of superlattices considerably improves the performance of the resulting phase-change memories. Despite this significant advance the origin of the improvement and the detailed switching mechanism were not clearly understood. Hence, the focus of this thesis is on the growth and characterization of such superlattices. Using particularly transmission electron microscopy the detailed crystal structure of such multilayers has been analyzed and explained in terms of the bonding nature of the alloys. Several switching mechanisms of superlattice phase-change memory in the literature were debated and shown that they were inconsistent with the actual structure of the films. In addition, it was shown that GeTe/Sb2Te3 superlattices can be an interesting platform to study mixed GeTe/Sb2Te3 alloys by illustrating in detail its thermal reconfiguration. In the final parts of the thesis the thin film growth is discussed with particular focus on engineering the substrate-film interface. In general, the results shed light on the structure and switching mechanism of GeTe/Sb2Te3 superlattice phase-change memories and pave way for growth of similar materials for ferroelectric, spintronic and thermoelectric applications

Exploring climate change vulnerability and adaptation among smallholder farmers in Nangarhar, Afghanistan: A social-ecological systems perspective

Climate change vulnerability and adaptation strategies for smallholder farmers in Afghanistan are critical issues that require urgent attention from national, regional, and global climate-savvy stakeholders. This study investigates the climate change perception and adaptation strategies of smallholder farmers in Nangarhar province, utilizing the social-ecological systems perspective. The study employs a qualitative research design, conducting 11 semi-structured interviews with smallholder farmers to explore their lived experience about climate change, adaptation challenges, and indigenous coping strategies. The study used thematic analysis to examine the collected data. The analysis revealed several key themes that emerged from the data, namely climate change perception, adaptation challenges, indigenous coping strategies, government support and intervention, crop-specific impact, economic impact and livelihood, information sources and communication channels, and concerns about floods. The study highlights the challenges faced by farmers, including difficulties in crop production, limited access to quality inputs, and the adverse effects of drought on agricultural productivity. The findings underscore the importance of developing effective adaptation strategies to mitigate the adverse effects of climate change on the agricultural sector and the livelihoods of smallholder farmers in Afghanistan. The study contributes to the understanding of the vulnerability of smallholder farmers to climate change and the importance of enhancing their adaptive capacity, with a specific focus on conflict-affected agrarian regions like Afghanistan

Lung Cancer Screening in Sub-Saharan Africa: A Scoping Review

https://digitalcommons.library.uab.edu/sp-expo/1020/thumbnail.jp