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Square arrays of artificial spin ice (ASI) constituting weakly interacting NiFe nano-islands, with length ~312 nm, width ~125 nm, thickness ~20 nm, and lattice constant ~570 nm, were fabricated on Nb thin film and on thermally grown 300 nm SiO2 on silicon. Detailed investigations of magnetic force microscopy (MFM) at room temperature, and magnetization M(H) loops and relaxation of remanent magnetization (Mr) at various temperatures were carried out in two in-plane field geometries, namely, parallel ("P"-parallel to the square lattice) and diagonal ("D"- 45° to the square lattice). The magnetic response of the ASI samples shows striking difference for insulating (SiO2), metallic (Nb, T > 6.6 K) and superconducting (Nb, T < 6.6 K) bases, and the field geometry. For instance, with the Nb base in the normal metallic state (T > 6.6 K), (1) in "P" geometry the M(H) loops are found to be more "S" shaped in comparison with that for SiO2 base; (2) the ratio of magnetic vertex population of Type II to Type III vertices extracted from MFM studies in "P"("D") geometry is ~1:1.1(1.2:1) that changed for the SiO2 base to ~2.1:1 (4: 1). However, the NiFe-ASI on both metallic Nb and SiO2 bases exhibit a highly athermal decay of magnetization, and the % change in Mr in about two hours at T = 10 K (300 K) lies in a range of ~1.07-1.80 (0.25-0.62). With Nb base in superconducting state (T < 6.6 K), the M(H) loops not only look radically different from those with SiO2 and metallic Nb as bases but also show significant difference in "P" and "D" geometries. These results are discussed in terms of inter-island magnetostatic energy as influenced by field geometry, presence of metallic Nb base and competing vortex pinning energy of superconducting Nb base. [ABSTRACT FROM AUTHOR]

Emerging multidrug resistant bacterial infections are burning public health concerns worldwide. There is an urgent need to explore alternative antimicrobial agents for effective management of bacterial infections. Garlic (Allium sativum) has been traditionally used for the treatment of different diseases since ancient times. The present study aims to evaluate the antimicrobial activity of aqueous extract of Allium sativum against multidrug resistant clinical isolates of pathogenic bacteria found in human urine in cases of urinary tract infection (UTI). A total of 166 uropathogens were evaluated for antibiotic susceptibility, 56% clinical isolates were found to have high degree of resistance with multiple antibiotic resistance (MAR) index >0.5. About 82% bacterial isolates with MAR index >0.5 were found to be susceptible to crude aqueous garlic extract. Thus, aqueous garlic extract (AGE) was found to possess effective anti-bacterial activity against multidrug resistant clinical pathogens and may be tested further as a natural dietary component to manage drug resistance bacteraemia. Therefore, alternate medicine practices with natural plant extract including garlic may be of great importance in combating public health challenges like UTI. [ABSTRACT FROM AUTHOR]