9 research outputs found

    Interaction of Adatoms and Molecules with Single-Layer Arsenene Phases

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    Columnar antiferromagnetic order of a MBene monolayer

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    First-principles density functional theory, combined with the Monte Carlo method, predicts that the Fe2B2 monolayer of the MBene family has a stable columnar antiferromagnetic (AFM) ground state. Below the critical temperature, T-c = 115 K in equilibrium, the spins rotate by the same amount in every other column of Fe atoms, but they retain the same direction in the same column. Under applied tensile strains, T-c and the order parameter can increase nonmonotonically. The onset of the columnar order can result in a transition from two dimension (2D) to 1D in magnetic, electronic, and conduction properties. The ordered magnetic state itself can be tuned by external magnetic field, whereby the columnar magnetic order changes to ferromagnetic order with a double hysteresis behavior. When terminated by Fluorine atoms, the columnar order changes to the AFM order with T-c rising above room temperature. This situation is rather unusual and insofar is fundamental for a realistic, strictly 2D monolayer and can have critical consequences in spin conduction

    The Effects of Wintering in Different Climatic Regions of Turkey on Some Physiological Characteristic of Caucasian Honey Bee (Apis mellifera caucasica) Colonies

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    This study was conducted in two locations have different altitudes in the cities which have different climates as Ankara, Ordu, Erzurum, Mersin. The purpose of this work was to define some physiological properties of the bees such as the survivability of colony, wintering ability, usage of stoked honey and to discuss all these data. This study lasted two years and the second year was the continuation of the first year. At the beginning of the year, colonies which has the same genotype were equalized as number of combs covered with bees, stocked honey and brood areas and so on. According to the data analysis, it was obtained that the quantity of the stocked honey was not statistically significant by the region×altitude×year interaction. However, year×region and region×altitude interactions were statistically significant. Similarly, it was obtained that the wintering ability was not statistically significant by the region×altitude×year interaction. The only year×region interaction was statistically significant. Also, descriptive statistics obtained for the survivability of the colonies (%) during the first and second year was added statistically to this application. As a result, this work showed that migratory beekeepers could reevaluate the regions which have the microclimate properties in Aegean, Mediterranean, and the Black Sea. And new research should be made by adding different species of honeybees for the performance of overwintering in different climates

    Above Room Temperature Ferromagnetism in Gd2B2 Monolayer with High Magnetic Anisotropy

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    The realization of 2D ultrathin crystals with a ferromagnetic ground state that is sustainable at room temperature has been a real challenge now. By combining ab initio density functional theory with Monte Carlo simulations, we predicted a new 2D structure, Gd2B2 monolayer, which maintains its mechanical stability at elevated temperatures. More remarkably, it has a ferromagnetic ground state with high permanent magnetic moment, which persists far above room temperature. It exhibits high magnetocrystalline anisotropy along particular directions. We find also that both its magnetic anisotropy and Curie temperature can largely be altered by applied strain providing an excellent magnetoelastic tunability. This novel 2D crystal with high magnetic moment and Curie temperature combined with high structural and thermal stability can offer critical applications in magnetoelectronics

    Magnetization of silicene via coverage with gadolinium: Effects of thickness, symmetry, strain, and coverage

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    When covered by gadolinium (Gd) atoms, silicene, a freestanding monolayer of Si atoms in a honeycomb network, remains stable above the room temperature and becomes a two-dimensional (2D) ferromagnetic semiconductor, despite the antiferromagnetic ground state of three-dimensional bulk GdSi2 crystal. In thin GdSi2 multilayers, even if magnetic moments are ordered parallel in the same Gd atomic planes, they are antiparallel between nearest Gd planes; hence they exhibit a ferrimagnetic behavior. In contrast, a freestanding Gd2Si2 monolayer constructed by covering silicene from both sides by Gd atoms is a stable antiferromagnetic metal due to the mirror symmetry. While multilayers covered by Gd from both sides having an odd number of Gd planes have a ferrimagneticlike ground state, even-numbered ones have antiferromagnetic ground state, but none of them is ferromagnetic. Silicon atoms intervening between Gd planes are responsible for these intriguing magnetic orders conforming with the recent experiments performed on Si(111) surface. Additionally, the magnetic states of these 2D gadolinium disilicide monolayers can be monitored by applied tensile strain and by the coverage/decoration of Gd. These predictions obtained by using first-principles, spin-polarized, density functional theory calculations combined with Monte Carlo simulations herald that C, B, Si, Ge, Sn, and their compounds functionalized by rare-earth atoms can lead to novel nanostructures in 2D spintronics

    Hypokalemic Paralysis and Respiratory Failure Due to Excessive Intake of Licorice Syrup

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    Meyan kökü glycyrrhizic acid içeren Glycyrrhiza glabra'nın köküdür. Aşırı meyan kökü alımı sodyum ve su retansiyonu, hipokalemi, hipertansiyon, metabolik alkaloz, düşük renin aktivitesi ve hipoaldosteronizm ile karekterize hipermineralokortikoidizm benzeri sendroma yol açabilir. Bu yazıda aşırı meyan kökü şerbeti içimi sonrası acil servise solunum sıkıntısı, kol ve bacaklarında güçsüzlük nedeniyle getirilen hipopotasemik paralizili 34 yaşındaki erkek hasta sunuldu. Acil Servise paralizi ve solunum sıkıntısıyla gelen hastalarda aşırı meyan kökü alımı olup olmadığının sorgulanması gerekliliğine dikkat çekilmesi amaçlandı. Kan potasyum düzeyi 1.4 mmol/L olan hastanın potasyum replasmanı sonrası solunum sıkıntısı ve kas kuvvet kaybı tamamen düzeldiLicorice is the root of Glycyrrhiza glabra, which has a herbal ingredient, glycyrrhizic acid. Excessive intake of licorice may cause a hypermineralocorticoidism-like syndrome characterized by sodium and water retention, hypokalemia, hypertension, metabolic alkalosis, low-renin activity, and hypoaldosteronism. In this paper, an 34 years old man who admitted to the emergency department with respiratory failure and marked muscle weakness of all extremities that progressed to paralysis after excessive intake of licorice syrup was presented. It was aimed to draw attention to the necessity of questioning whether there is excessive intake of licorice or not in patients who admitted to emergency department with paralysis and dyspnea. Plasma potassium concentration of the patient was 1.4 mmol/L. The patient's respiratory distress and loss of muscle strength recovered completely after potassium replacemen

    Comparing the efficacy of regorafenib and 5-fluorouracil-based rechallenge chemotherapy in the third-line treatment of metastatic colorectal cancer

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    Abstract Background The optimal treatment for metastatic colorectal cancer (mCRC) after the second line is still controversial. Regorafenib has been the standard of care in this setting as it improved overall survival (OS) compared to placebo. In real-world practice chemotherapy rechallenge is also a preferred option even though supporting evidence is not enough. We aim to compare the efficacy of regorafenib and 5-fluorouracil-based (5-FU) rechallenge treatment in the third line setting of mCRC. Methods In this retrospective multi-institutional trial, mCRC patients from 21 oncology centers who progressed after 2 lines of chemotherapy were analyzed. Patients who were treated with regorafenib or rechallenge therapy in the third-line setting were eligible. Rechallenge chemotherapy was identified as the re-use of the 5-FU based regimen which was administered in one of the previous treatment lines. OS, disease control rate (DCR), progression free survival (PFS) and toxicity were analyzed. Results Three hundred ninety-four mCRC patients were included in the study. 128 (32.5%) were in the rechallenge, and 266 (67.5%) were in the regorafenib group. Median PFS was 5.82 months in rechallenge and 4 months in regorafenib arms (hazard ratio:1.45,95% CI, p = 0.167). DCR was higher in the rechallenge group than regorafenib (77% vs 49.5%, respectively, p =  < 0.001). Median OS after the third-line treatment was 11.99 (95% CI, 9.49–14.49) and 8.08 months (95% CI, 6.88–9.29) for rechallenge and regorafenib groups, respectively (hazard ratio:1.51, 95% CI, p < 0.001). More adverse effects and discontinuation were seen with regorafenib treatment. Conclusion Our study revealed that higher disease control and OS rates were achieved with rechallenge treatment compared to regorafenib, especially in patients who achieved disease control in one of the first two lines of therapy
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