Spin order dependent skyrmion stabilization in MnFeCoGe hexagonal magnets

Topological magnetic skyrmions in centrosymmetric systems exhibit a higher degrees of freedom in their helicity, hence possess a great potential in the advanced spintronics including skyrmion based quantum computation. However, the centrosymmetric magnets also display non-topological trivial bubbles along with the topological skyrmions. Hence it is utmost priority to investigate the impact of different magnetic ground states and their underlying interactions on the stabilization of magnetic skyrmions in cetrosymmetric magnets. Here, we present a combined theoretical and experimental study on the role of non-collinear magnetic ground state on the skyrmion stabilization in a series of exchange frustrated non-collinear ferromagnetic system MnFe1-xCoxGe. With the help of neutron diffraction (ND) and Lorentz transmission electron microscopy (LTEM) studies, we show that hexagonal skyrmions lattice emerges as a stable field driven state only when the underlying magnetic ground state is collinear with easy-axis anisotropy. In contrast, non-topological type-II bubbles are found to be stable state in the case of non-collinear magnetic ordering with partial in-plane anisotropy. Furthermore, we also find that the skyrmions transform to the non-topological bubbles when the system undergoes a spin reorientation transition from the easy-axis to easy-cone ferromagnetic phase. Our results categorically establish the significant role of in-plane magnetic moment/anisotropy that hinders the stability of skyrmion both in the case of collinear and non-collinear magnets. Thus, the present study offers a wide range of opportunities to manipulate the stability of dipolar skyrmions by changing the intrinsic characteristics of the materials.Comment: 18 pages, 4 figure

Effect of garlic on cardiovascular disorders: a review

Garlic and its preparations have been widely recognized as agents for prevention and treatment of cardiovascular and other metabolic diseases, atherosclerosis, hyperlipidemia, thrombosis, hypertension and diabetes. Effectiveness of garlic in cardiovascular diseases was more encouraging in experimental studies, which prompted several clinical trials. Though many clinical trials showed a positive effect of garlic on almost all cardiovascular conditions mentioned above, however a number of negative studies have recently cast doubt on the efficary of garlic specially its cholesterol lowering effect of garlic. It is a great challenge for scientists all over the world to make a proper use of garlic and enjoy its maximum beneficial effect as it is the cheapest way to prevent cardiovascular disease. This review has attempted to make a bridge the gap between experimental and clinical study and to discuss the possible mechanisms of such therapeutic actions of garlic

Tunable room temperature magnetic skyrmions in centrosymmetric kagome magnet Mn4Ga2Sn

Skyrmions are vortex-like magnetic textures typically observed in non-centrosymmetric systems, i.e. those with no centre of inversion. Here, using Lorentz transmission electron microscopy supported with micromagnetic simulations the authors report the observation of skyrmion lattices in the centrosymmetric kagome ferromagnet Mn4Ga2Sn, where a controlled switching between the topological skyrmions and non-topological type-II magnetic bubbles can be realized by manipulating the in-plane magnetic field at the optimal magnetic anisotropy

Higher order exchange driven noncoplanar magnetic state and large anomalous Hall effects in electron doped kagome magnet Mn3Sn

Abstract Owing to geometrical frustration in the kagome lattice, Mn3Sn displays a 120° in-plane triangular antiferromagnetic order, a manifestation of exchange interaction within the Heisenberg model. Here, we show the formation of a tunable noncoplanar magnetic ground state stabilized by higher-order exchange interactions in electron-doped Mn3Sn samples. Our density Functional Theory calculations reveal that the higher-order exchange induces a partial out-of-plane alignment of the Mn moments, resulting in a canted magnetic state, further experimentally confirmed by neutron diffraction study along with 60 T magnetic and Hall resistivity measurements. Interestingly, we find a large scalar spin chirality-induced Hall signal depending on the degree of non-coplanarity of the Mn moments. Additionally, we demonstrate simultaneous manipulation of two-component order-parameter in the system, where the two Hall signals can be independently manipulated. The present study explores the quantum phenomena associated with the coexistence of multiple magnetic orders and their prospective use in spintronic devices

Antihyperglycemic and anti-inflammatory effects of fermented food paste in high-fat diet and streptozotocin-challenged mice

Noraisyah Zulkawi,1 Kam Heng Ng,1 Nur Rizi Zamberi,2,3 Swee Keong Yeap,4 Dilan A Satharasinghe,5 Sheau Wei Tan,2 Wan Yong Ho,6 Nur Yuhasliza Abd Rashid,3 Mohd Izwan Md Lazim,3 Anisah Jamaluddin,3 Noorjahan Banu Alitheen,2,7 Kamariah Long3 1Technical Research – Product Development Department, Elken Global Sdn. Bhd, Kuala Lumpur, Malaysia; 2Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia; 3Malaysian Agricultural Research and Development Institute (MARDI), Serdang, Selangor, Malaysia; 4China-ASEAN College of Marine Sciences, Xiamen University Malaysia, Sepang, Selangor, Malaysia; 5Department of Basic Veterinary Sciences, Faculty of Veterinary Medicine & Animal Science, University of Peradeniya, Peradeniya, Sri Lanka; 6School of Biomedical Sciences, The University of Nottingham Malaysia Campus, Semenyih, Selangor, Malaysia; 7Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Science, Universiti Putra Malaysia, Serdang, Selangor, Malaysia Background: Fermented food has been widely consumed as health food to ameliorate or prevent several chronic diseases including diabetes. Xeniji™, a fermented food paste (FFP), has been previously reported with various bioactivities, which may be caused by the presence of several metabolites including polyphenolic acids, flavonoids, and vitamins. In this study, the anti-hyperglycemic and anti-inflammatory effects of FFP were assessed. Methods: In this study, type 2 diabetes model mice were induced by streptozotocin and high-fat diet (HFD) and used to evaluate the antihyperglycemic and anti-inflammatory effects of FFP. Mice were fed with HFD and challenged with 30 mg/kg body weight (BW) of streptozotocin for 1 month followed by 6 weeks of supplementation with 0.1 and 1.0 g/kg BW of FFP. Metformin was used as positive control treatment. Results: Xeniji™-supplemented hyperglycemic mice were recorded with lower glucose level after 6 weeks of duration. This effect was contributed by the improvement of insulin sensitivity in the hyperglycemic mice indicated by the oral glucose tolerance test, insulin tolerance test, and end point insulin level. In addition, gene expression study has shown that the antihyperglycemic effect of FFP is related to the improvement of lipid and glucose metabolism in the mice. Furthermore, both 0.1 and 1 g/kg BW of FFP was able to reduce hyperglycemia-related inflammation indicated by the reduction of proinflammatory cytokines, NF-kB and iNOS gene expression and nitric oxide level. Conclusion: FFP potentially demonstrated in vivo antihyperglycemic and anti-inflammatory effects on HFD and streptozotocin-induced diabetic mice. Keywords: fermented foods, diabetic, inflammation, high-fat diet, lipid metabolism, glucose metabolis

Design and implementation of potentiometer-based nonlinear transducer emulator

This work attempts to design and implement in hardware a transducer with a nonlinear response using potentiometer. Potentiometer is regarded as a linear transducer, while a the response of a nonlinear transducer can be treated as a concatenation of linear segments made out of the response curve of an actual nonlinear transducer at the points of inflections being exhibited by the nonlinear curve. Each straight line segment is characterized by its slope and a constant, called the y-intercept, which is ultimately realized by a corresponding electronic circuit. The complete circuit diagram is made of three stages: (i) the input stage for range selection, (ii) a digital logic to make appropriate selection, (iii) a conditioning circuit for realizing a given straight-line segment identified by its relevant slope and reference voltage. The simulation of the circuit is carried using MULTISIM, and the designed circuit is afterward tested to verify that variations of the input voltage give us an output voltage very close to the response pattern envisaged in the analytical stage of the design. The utility of this work lies in its applications in emulating purpose built transducers that could be used to nicely emulate a transducer in a real world system that is to be controlled by a programmable digital system