Skyrmion-(Anti)Vortex Coupling in a Chiral Magnet-Superconductor Heterostructure.

We report experimental coupling of chiral magnetism and superconductivity in [IrFeCoPt]/Nb heterostructures. The stray field of skyrmions with radius ≈50 nm is sufficient to nucleate antivortices in a 25 nm Nb film, with unique signatures in the magnetization, critical current, and flux dynamics, corroborated via simulations. We also detect a thermally tunable Rashba-Edelstein exchange coupling in the isolated skyrmion phase. This realization of a strongly interacting skyrmion-(anti)vortex system opens a path toward controllable topological hybrid materials, unattainable to date.

Spin-droplet state of an interacting 2D electron system.

We report thermodynamic magnetization measurements of two-dimensional electrons in several high-mobility Si metal-oxide-semiconductor field-effect transistors. We provide evidence for an easily polarizable electron state in a wide density range from insulating to deep into the metallic phase. The temperature and magnetic field dependence of the magnetization is consistent with the formation of large-spin droplets in the insulating phase. These droplets melt in the metallic phase with increasing density and temperature, though they survive up to large densities.

The effects of RU 41.740, a glycoprotein immunomodulating agent derived from Klebsiella pneumoniae, on intra-abdominal abscess formation in mice.

The prophylactic and therapeutic efficacies of the immunomodulating agent RU 41.740 (a glycoprotein extract from Klebsiella pneumoniae) were studied in a murine model of intra-abdominal abscess formation with Bacteroides fragilis, Escherichia coli, and bran as an abscess-potentiating agent. Parenteral injection of RU 41.740, either before or after injection of an abscess-inducing mixture (AIM), was associated with significantly diminished incidence and size of abscesses. Abscess incidence and size were significantly decreased by oral administration of RU 41.740 after, but not before, AIM injection. Abscess formation and resolution are the results of complex interactions of host defence mechanisms with bacteria and potentiating agent, and RU 41.740 has been shown previously to activate both macrophage and neutrophil function. These results indicate that activation of non-specific defences may protect against abscess development in chronic sepsis.

Mycobacteria of the intracellulare-scrofulaceum group in soils from the Adelaide area.

Soil samples from the Adelaide area--where organisms belonging to the Mycobacterium intracellulare-scrofulaceum (MIS) group are rarely encountered in sputum of persons under investigation of pulmonary mycobacterial disease--were examined for the MIS group. Thirty-one per cent were positive for MIS organisms and 17% were positive for MIS serotypes known to be disease-associated. Comparison with an earlier study of soils from the Brisbane area--where this group of organisms is frequently isolated from sputum of persons under investigation for pulmonary mycobacterial disease--suggests that the disease-associated MIS serotypes are significantly more common in the environment of the Brisbane area. This implies a positive correlation, and consolidates existing evidence that the environment is the reservoir of, and a source of infection with, organisms of the MIS group.

Clinical utility of the polymerase chain reaction to diagnose Mycoplasma pneumoniae infection.

The diagnosis of Mycoplasma pneumoniae infection currently relies on serological methods which may be slow to produce diagnostic results and may be inconvenient for both the clinician and the patient. This study was designed to assess whether or not the polymerase chain reaction (PCR) is a useful additional diagnostic method. Comparison was therefore made with serology as it is routinely practiced. PCR was used to examine for the presence of M. pneumoniae DNA in throat swab specimens obtained from 99 hospitalized patients investigated for a range of respiratory pathogens including M. pneumoniae. PCR detected M. pneumoniae DNA in 24 adults and 25 children, which is significantly more than the 32 patients found to be antibody positive by the particle agglutination test (p = 0.001). M. pneumoniae DNA was not detected in any of the throat swabs from 32 apparently healthy volunteers. PCR inhibitors were not detected in any of the samples tested. Significantly more children (88%) than adults (38%) were found to be anti-mycoplasma antibody-positive (p < 0.0001). Routine clinical practice was reflected in the fact that 56 patients (57%) had indeterminate serological results because only single sera were obtained. The sensitivity and specificity of PCR were assessed to be 92% and 98% respectively, using a combination of serological and clinical data as the benchmark. PCR appears to have advantages over serological testing, both with respect to accuracy and convenience of single specimen testing. The poor performance of serological tests in adults makes PCR especially useful in this age group.

The use of syngeneic cells producing human somatotropic hormone (hSTH) for immunization of mice and development of hybridomas.

We studied the possibility of syngeneic cells expressing heterologous protein being used for sensitization of mice and production of hybridomas. Recombinant retroviral vector containing cloned human somatotropic hormone (hSTH) gene was used to express hSTH in BALB/3T3 cells. BALB/c mice were injected intrasplenically (i/s) or combination of intraperitoneally (i/p) and intrasplenically with hSTH-producing cells. Sensitized splenocytes were fused with myeloma cell P3X63-AgB.653. Screening for anti-hSTH hybridomas was performed by enzyme-linked immunoassay. Both single i/s injection of producer cells as well as combined i/s and i/p injections were effective for sensitization of splenocytes. Combined injection was effective for production of IgG and IgM secreting hybridomas. Single i/s injection led to generation of only IgM producing hybridomas. The results proved that syngeneic cells expressing genes of heterologous proteins can be used for splenocyte sensitization and hybridoma preparation.

[Identification of a protein product of a novel human gene SON and the biological effect upon administering a changed form of this gene into mammalian cells]. / Identifikatsiia belka-produkta novogo gena cheloveka SON i biologichekii éffekt pri vvedenii izmenennoi formy étogo gena v kletki mlekopitaiushchikh.

We have investigated the functional activity of human son gene, that possesses the homology to mos and myc genes. Specific antibodies (antiserum) were raised to synthetic peptide, that corresponds to son-protein 943-963 amino acid residues. With this antiserum the presence of son-protein was showed in lysates of cultured human cells transformed by adenovirus type 5, RAT 2 cells and primary human embryonic fibroblasts. son-Protein molecular weight (92 kDa) was determined by the method of electrophoresis in SDS-polyacrylamide gel. Thus, it was shown the presence of son gene protein in animal and human cells. To determine a possible son gene role in mammalian cells we have cloned the 3' part (2667 b.p.) of son cDNA in retroviral vector pPS-3-neo. Transformed cells of different lines were selected. A large portion of this cells changed their morphology. New protein product (120 k), that reacted with antiserum to son specific peptide, was found together with p92son in these clones.

[Expression of human growth hormone in cultured mouse fibroblasts]. / Ekspressiia gormona rosta cheloveka v perevivaemykh fibroblastakh myshi.

The new system for the transfer and expression of foreign genes based on retroviral vectors pPS-neo, conferring neomycin resistance was constructed. The BALB/c mouse cell lines producing highly active human growth hormone (more than 7 micrograms/ml into culture medium) were constructed using these vectors. An antibody column was used to purify the growth hormone from cell culture medium. Possibilities of producers to be applied for gene therapy are discussed.

[Human diseases caused by leptospirae of the canicola serogroup in the Krasnodar Territory]. / Zabolevaniia cheloveka, vyzvannye leptospirami serogruppy canicola, v Krasnodarskom krae.

During the period of 34 years (1957-1990) diseases caused by leptospires of the serogroup canicola were confirmed in 2.7% of the total number of patients. The analysis revealed that in the presence of epidemic outbreaks Leptospira infection caused by bacteria of the serogroup canicola occurred 1.7 times more often than at the time when such outbreaks were absent. Periodic increases of leptospirosis caused by this serogroup were registered in individual towns and regions of the territory in different years. The analysis of 33 medical histories made it possible to state that the clinical manifestations of leptospirosis caused by bacteria of the serogroup canicola were characteristic of Leptospira infections caused not only by this serovar. As a rule, this kind of leptospirosis was registered in rural and urban areas as individual isolated cases.

A magnetically focused molecular beam of ortho-water.

Like dihydrogen, water exists as two spin isomers, ortho and para, with the nuclear magnetic moments of the hydrogen atoms either parallel or antiparallel. The ratio of the two spin isomers and their physical properties play an important role in a wide variety of research fields, ranging from astrophysics to nuclear magnetic resonance (NMR). Unlike ortho and para H(2), however, the two water isomers remain challenging to separate, and as a consequence, very little is currently known about their different physical properties. Here, we report the formation of a magnetically focused molecular beam of ortho-water. The beam we formed also had a particular spin projection. Thus, in the presence of holding magnetic fields, the water molecules are hyperpolarized, laying the foundation for ultrasensitive NMR experiments in the future.