Transfer of magnetic anisotropy in epitaxial Co/NiO/Fe trilayers.

The magnetic properties of Co(10 Å)/NiO(40 Å)/Fe trilayer epitaxially grown on W(110) substrate were investigated with use of x-ray magnetic linear dichroism (XMLD) and x-ray magnetic circular dichroism (XMCD). We showed that magnetic anisotropy of Fe film that can be controlled by a thickness-driven spin reorientation transition is transferred via interfacial exchange coupling not only to NiO layer but further to ferromagnetic Co overlayer as well. Similarly, a temperature driven spin reorientation of Fe sublayer induces a reorientation of NiO spin orientation and simultaneous switching of the Co magnetization direction. Finally, by element specific XMCD and XMLD magnetic hysteresis loop measurements we proved that external magnetic field driven reorientation of Fe and Co magnetizations as well as NiO Néel vector are strictly correlated and magnetic anisotropy fields of Fe and Co sublayers are identical despite the different crystal structures.

Tunable interplay between exchange coupling and uniaxial magnetic anisotropy in epitaxial CoO/Au/Fe trilayers.

We show that the interaction between ferromagnetic Fe(110) and antiferromagnetic CoO(111) sublayers can be mediated and precisely tuned by a nonmagnetic Au spacer. Our results prove that the thickness of the Fe and Au layers can be chosen to modify the effective anisotropy of the Fe layer and the strength of the exchange bias interaction between Fe and CoO sublayers. Well-defined and tailorable magnetic anisotropy of the ferromagnet above Néel temperature of the antiferromagnet is a determining factor that governs exchange bias and interfacial CoO spins orientation at low temperatures. In particular, depending on the room temperature magnetic state of Fe, the low-temperature exchange bias in a zero-field cooled system can be turned "off" or "on". The other way around, we show that exchange bias can be the dominating magnetic anisotropy source for the ferromagnet and it is feasible to induce a 90-degree rotation of the easy axis as compared to the initial, exchange bias-free easy axis orientation.

Tunable magnetic anisotropy of antiferromagnetic NiO in (Fe)/NiO/MgO/Cr/MgO(001) epitaxial multilayers.

We report on the magnetic properties of antiferromagnetic NiO(001) thin films in epitaxially grown NiO/MgO(dMgO)/Cr/MgO(001) system for different thicknesses of MgO, dMgO. Results of X-ray Magnetic Linear Dichroism show that together with an increase of dMgO, rotation of NiO spins from in-plane towards out-of-plane direction occurs. Furthermore, we investigated how the proximity of Fe modifies the magnetic state of NiO in Fe/NiO/MgO(dMgO)/Cr/MgO(001). We proved the existence of a multidomain state in NiO as a result of competition between the ferromagnet/antiferromagnet exchange coupling and strain exerted on the NiO by the MgO buffer layer.

Detection of squirrel poxvirus by nested and real-time PCR from red (Sciurus vulgaris) and grey (Sciurus carolinensis) squirrels.

BACKGROUND: Squirrel poxvirus (SQPV) is highly pathogenic to red squirrels (Sciurus vulgaris), and is a significant contributing factor to the local extinction of the species in most parts of England and Wales, where infection is endemic in Eastern grey squirrel (Sciurus carolinensis) populations. Although a nested PCR assay has been used successfully to study the epidemiology of SQPV, samples have a long processing time and the assay is not quantifiable. RESULTS: This project describes the design and optimization of a real-time PCR for SQPV. Comparison with the nested PCR showed the real-time assay to be more sensitive by one log and able to detect approximately 144 genome copies per mg of tissue. CONCLUSIONS: The real-time PCR has been used to quantify viral genome load in tissues from diseased and apparently healthy red and grey squirrels, and suggests that the titre of virus in tissues from diseased red squirrels is considerably higher than that found even in a grey squirrel with cutaneous lesions.

Fine tuning of ferromagnet/antiferromagnet interface magnetic anisotropy for field-free switching of antiferromagnetic spins.

We show that in a uniform thickness NiO(111)/Fe(110) epitaxial bilayer system, at given temperature near 300 K, two magnetic states with orthogonal spin orientations can be stabilized in antiferromagnetic NiO. Field-free, reversible switching between these two antiferromagnetic states is demonstrated. The observed phenomena arise from the unique combination of precisely tuned interface magnetic anisotropy, thermal hysteresis of spin reorientation transition and interfacial ferromagnet/antiferromagnet exchange coupling. The possibility of field-free switching between two magnetic states in an antiferromagnet is fundamentally interesting and can lead to new ideas in heat assisted magnetic recording technology.

Driving the polar spin reorientation transition of ultrathin ferromagnets with antiferromagnetic-ferromagnetic phase transition of nearby FeRh alloy film.

We show that in-plane to out-of-plane magnetization switching of a ferromagnetic layer can be driven by antiferromagnetic-ferromagnetic phase transition in a nearby FeRh system. For FeRh/Au/FeAu trilayers, the impact of the magnetic phase transition of FeRh onto the perpendicular magnetization of monoatomic FeAu superlattices is transferred across the Au spacer layer via interlayer magnetic coupling. The polar spin reorientation process of the FeAu spins driven by the magnetic phase transition in the FeRh reveals its major features; namely it is reversible and displays hysteresis.

Correction: Fine tuning of ferromagnet/antiferromagnet interface magnetic anisotropy for field-free switching of antiferromagnetic spins.

Correction for 'Fine tuning of ferromagnet/antiferromagnet interface magnetic anisotropy for field-free switching of antiferromagnetic spins' by M. Slezak et al., Nanoscale, 2020, DOI: 10.1039/d0nr04193a.

Application of 31P NMR spectroscopy in clinical analysis of changes of serum phospholipids in leukemia, lymphoma and some other non-haematological cancers.

The sodium salt of cholic acid added to serum caused separation of three phospholipid peaks located upfield from inorganic phosphate (Pi) due to phosphatidylethanolamine with sphingomyelin (PE + SM), lysophosphatidylcholine (LPC), and phosphatidylcholine (PC). 31P NMR spectra were obtained from the sera of 15 healthy volunteers, 10 individuals suffering from acute leukemia, 4 persons with malignant lymphomas, 13 patients with digestive tract tumors and 5 with renal cell carcinoma. The present studies confirmed our previous observation that the 31P spectra of sera of patients with acute leukemia and malignant lymphomas revealed a significant decrease in the phospholipid level at the time of diagnosis and displayed a good correlation between spectral parameters and stage of disease in patients responding and non-responding to therapy. Contrary to the preliminary studies, peaks from PE + SM and PC, and also a peak from LPC were observed. Changes in phospholipids in the 31P NMR spectra observed in patients suffering from digestive tract tumors and renal cell carcinoma were primarily dependent on the advance of the disease. Most of our patients with these cancers were in the early stage of the disease, and the spectra showed statistically significant decrease only in the LPC peak area, and no statistically significant changes of peak areas of PC and PE+SM in comparison to the control group. In conclusion, we can state that the LPC peak area is the most sensitive indicator in the monitoring of treatment in acute leukemia and malignant lymphomas. Our results also showed that LPC peak areas were decreased in the early stages of digestive tract tumors and a renal cell carcinoma.

Solar activity and myocardial infarction.

The correlation between the incidence of myocardial infarction, sudden cardiac death, the solar activity and geomagnetism in the period 1969-1976 was studied, basing on Wroclaw hospitals material registered according to WHO standards; sudden death was assumed when a person died within 24 hours after the onset of the disease. The highest number of infarctions and sudden deaths was detected for 1975, which coincided with the lowest solar activity, and the lowest one for the years 1969-1970 coinciding with the highest solar activity. Such an inverse, statistically significant correlation was not found to exist between the studied biological phenomena and geomagnetism.

Results of rubber band ligation of esophageal varices.

BACKGROUND: The aim of the paper is to analyze the results of endoscopic rubber band ligation of esophageal varices performed between 1 January 1998 and 1 November 2000 at the Department of GI Surgery of 4th Military University Hospital. MATERIAL AND METHODS: Cases of 50 patients with massive upper GI variceal bleeding present on admission or with the history of such a bleeding were reviewed. A total of 85 endoscopic procedures of rubber band ligation were performed. In 9 (18%) cases ligation was performed due to massive variceal bleeding, in 1 case the complementary obliteration of stomach fundus varices with Aethoxysclerol was performed. In 10 (20%) cases in grade C of Child-Pough scale of liver failure, 3 endoscopic procedures were performed, in 15 (30%) in grade B--2 procedures, in the remaining 25 (50%) cases, also in grade B--1 procedure was performed. Procedures were conducted with Wilson-Cook Multi-Band Ligator SAEED SixShooter. RESULTS: In all cases with non-bleeding esophageal varices the overall good result of treatment was achieved, with collapsing of variceal columns. In 8 (88.8%) of 9 cases treated due to variceal bleeding, good hemostasis was achieved and no reintervention was necessary. In 1 case of massive variceal bleeding endoscopic treatment failed and patient eventually died. In 25 (50%) cases the complementary (1 or 2) rubber band ligations were performed. Follow-up period has ranged from 1 to 34 months. No cases of severe complications after the procedure were noted. In early period after the procedure 43 (86%) patients complained of transient, mild retrosternal pain and mild to moderate dysphagia. CONCLUSIONS: Endoscopic rubber band ligation is a safe and effective treatment for esophageal varices both in cases of variceal bleeding and as elective procedure.