Highly Efficient Room-Temperature Spin-Orbit-Torque Switching in a Van der Waals Heterostructure of Topological Insulator and Ferromagnet

All-Van der Waals (vdW)-material-based heterostructures with atomically sharp interfaces offer a versatile platform for high-performing spintronic functionalities at room temperature. One of the key components is vdW topological insulators (TIs), which can produce a strong spin-orbit-torque (SOT) through the spin-momentum locking of their topological surface state (TSS). However, the relatively low conductance of the TSS introduces a current leakage problem through the bulk states of the TI or the adjacent ferromagnetic metal layers, reducing the interfacial charge-to-spin conversion efficiency (qICS). Here, a vdW heterostructure is used consisting of atomically-thin layers of a bulk-insulating TI Sn-doped Bi1.1Sb0.9Te2S1 and a room-temperature ferromagnet Fe3GaTe2, to enhance the relative current ratio on the TSS up to ≈20%. The resulting qICS reaches ≈1.65 nm-1 and the critical current density Jc ≈0.9 × 106 Acm-2 at 300 K, surpassing the performance of TI-based and heavy-metal-based SOT devices. These findings demonstrate that an all-vdW heterostructure with thickness optimization offers a promising platform for efficient current-controlled magnetization switching at room temperature.

Suspected human intravenous immunoglobulin-induced acute haemolytic anaemia in a dog

A 2-year-old mixed breed dog presented with a 1-year history of crust and erosion on the nasal planum. Because histopathological examination revealed ruptured intraepidermal pustules and superficial dermal inflammation, the dog was diagnosed with pemphigus foliaceus. Human intravenous immunoglobulin was administered in two consecutive doses of 0.5 g/kg/day due to poor therapeutic response to previous immunosuppressive therapy. From Day 3 after the first dose of human intravenous immunoglobulin, tachypnoea, pale mucous membrane, haemoglobinuria and haemoglobinemia were observed, thus confirming haemolytic anaemia. Other drug-induced haemolytic anaemias were excluded because no additional drugs had been administered before the haemolysis occurred. Immune-mediated haemolytic anaemia was also excluded because the direct antiglobulin test was negative. Two transfusions were performed, and haemolysis was not observed from Day 4 of haemolytic anaemia onset. In conclusion, human intravenous immunoglobulin-induced haemolytic anaemia should be considered in dogs that develop haemolysis following the administration of human intravenous immunoglobulin.

Improvement of gene transfer to cervical cancer cell lines using non-viral agents

Virus-like particles (VLPs) composed of recombinant capsid protein L1 and L2 of human papillomavirus type 16 were conjugated with polylysine (PL) and gene transfer was performed using VLP-PL conjugates to allow the expression of targeted gene. When HeLa cells were incubated with VLP-PL conjugate coupled with plasmid cytomegalovirus beta-galactosidase (pCMVbeta-gal), about 10% of cells were transfected and demonstrated beta-galactosidase activity. Hence chloramphenicol acetyltransferase activity was also expressed significantly in VLP-PL-plasmid simian virus 2 chloramphenicol acetyl transferase (pSV2CAT)-transfected cells, VLP-PL conjugate was tested whether it could transfer a tumor suppressor gene, pCMVp53, to HeLa cells and the exogenously provided p53 gene complexed to VLP-PL conjugate was detected from HeLa cells by polymerase chain reaction (PCR) analysis. Interestingly, additional increase of transfection efficiency was demonstrated in the presence of poloxamer 407 when C-33A cells were transfected with VLP-PL-pCMVbeta-gal complex. The result support the notion that VLP-PL conjugate may be a promising vector to transfer genetic materials into cancer cells and poloxamer 407 can be used for enhancing the transfection efficiency of VLP-PL conjugate.

Distribution of Necator americanus and Ancylostoma duodenale in Liberia

In the first country-wide survey of hookworm infection in Liberia, diagnosis by test-tube filter-paper cultivation revealed a prevalence of more than 90%. This sensitive technique also permitted differential species determination. Necator americanus was found to occur in all regions and in a high proportion of the persons examined. Ancylostoma duodenale was mainly confined to a narrow coastal belt, and usually parasitized individuals harbouring N. americanus as well. The average number of eggs per gram of faeces (EPG) of infected individuals was lowest in the population of the hinterland. During the latter part of the studies a modified test-tube filter-paper cultivation technique was used in combination with dilution counting to obtain data on intensity of infection separately for the 2 species. For N. americanus there was little regional difference in the intensity of infection, but the EPG for A. duodenale was much higher in people living in the coastal area.