On some Calcaronea (Porifera: Calcarea) from the Barents Sea and adjacent Polar Basin.

Four common calcareous sponge species from the Arctic are described. One species, Sycandra rappi Morozov sp. nov.

A preliminary account of the Arctic/Subarctic Suberites (Porifera: Demospongiae) fauna.

Sponges of the genus Suberites are quite polymorphic and diverse, yet the delimitation of species within the group has always been challenging since there are only a few spicule types that show little, or sometimes no variation in closely allied species. Koltun (1966) created a variety, S. domuncula var.

Biochemical and Structural Diversification of C Photosynthesis in Tribe Zoysieae (Poaceae).

C photosynthesis has evolved independently multiple times in grass lineages with nine anatomical and three biochemical subtypes. Chloridoideae represents one of the separate events and contains species of two biochemical subtypes, NAD-ME and PEP-CK. Assessment of C photosynthesis diversification is limited by species sampling.

TAPBPR employs a ligand-independent docking mechanism to chaperone MR1 molecules.

Chaperones tapasin and transporter associated with antigen processing (TAP)-binding protein related (TAPBPR) associate with the major histocompatibility complex (MHC)-related protein 1 (MR1) to promote trafficking and cell surface expression. However, the binding mechanism and ligand dependency of MR1/chaperone interactions remain incompletely characterized. Here in vitro, biochemical and computational studies reveal that, unlike MHC-I, TAPBPR recognizes MR1 in a ligand-independent manner owing to the absence of major structural changes in the MR1 α helix between empty and ligand-loaded molecules.

TAPBPR promotes antigen loading on MHC-I molecules using a peptide trap.

Chaperones Tapasin and TAP-binding protein related (TAPBPR) perform the important functions of stabilizing nascent MHC-I molecules (chaperoning) and selecting high-affinity peptides in the MHC-I groove (editing). While X-ray and cryo-EM snapshots of MHC-I in complex with TAPBPR and Tapasin, respectively, have provided important insights into the peptide-deficient MHC-I groove structure, the molecular mechanism through which these chaperones influence the selection of specific amino acid sequences remains incompletely characterized. Based on structural and functional data, a loop sequence of variable lengths has been proposed to stabilize empty MHC-I molecules through direct interactions with the floor of the groove.

Production of soluble pMHC-I molecules in mammalian cells using the molecular chaperone TAPBPR.

Current approaches for generating major histocompatibility complex (MHC) Class-I proteins with desired bound peptides (pMHC-I) for research, diagnostic and therapeutic applications are limited by the inherent instability of empty MHC-I molecules. Using the properties of the chaperone TAP-binding protein related (TAPBPR), we have developed a robust method to produce soluble, peptide-receptive MHC-I molecules in Chinese Hamster Ovary cells at high yield, completely bypassing the requirement for laborious refolding from inclusion bodies expressed in E.coli.

High throughput pMHC-I tetramer library production using chaperone-mediated peptide exchange.

Peptide exchange technologies are essential for the generation of pMHC-multimer libraries used to probe diverse, polyclonal TCR repertoires in various settings. Here, using the molecular chaperone TAPBPR, we develop a robust method for the capture of stable, empty MHC-I molecules comprising murine H2 and human HLA alleles, which can be readily tetramerized and loaded with peptides of choice in a high-throughput manner. Alternatively, catalytic amounts of TAPBPR can be used to exchange placeholder peptides with high affinity peptides of interest.

Flavin Reductase Contributes to Pneumococcal Virulence by Protecting from Oxidative Stress and Mediating Adhesion and Elicits Protection Against Pneumococcal Challenge.

Pneumococcal flavin reductase (FlaR) is known to be cell-wall associated and possess age dependent antigenicity in children. This study aimed at characterizing FlaR and elucidating its involvement in pneumococcal physiology and virulence. Bioinformatic analysis of FlaR sequence identified three-conserved cysteine residues, suggesting a transition metal-binding capacity.

Crystal structure of a TAPBPR-MHC I complex reveals the mechanism of peptide editing in antigen presentation.

Central to CD8 T cell-mediated immunity is the recognition of peptide-major histocompatibility complex class I (p-MHC I) proteins displayed by antigen-presenting cells. Chaperone-mediated loading of high-affinity peptides onto MHC I is a key step in the MHC I antigen presentation pathway. However, the structure of MHC I with a chaperone that facilitates peptide loading has not been determined.

Floquet-Bloch solutions in a sawtooth photonic crystal.

Band structure of a sawtooth photonic crystal for optical wave propagation along the axis of periodicity is investigated. Floquet-Bloch solutions are found and illustrated for the bandgaps, allowed bands, and bandedges of the crystal. Special attention is given to the cases where Floquet-Bloch solutions become periodic functions.

Interaction of TAPBPR, a tapasin homolog, with MHC-I molecules promotes peptide editing.

Peptide loading of major histocompatibility complex class I (MHC-I) molecules is central to antigen presentation, self-tolerance, and CD8(+) T-cell activation. TAP binding protein, related (TAPBPR), a widely expressed tapasin homolog, is not part of the classical MHC-I peptide-loading complex (PLC). Using recombinant MHC-I molecules, we show that TAPBPR binds HLA-A*02:01 and several other MHC-I molecules that are either peptide-free or loaded with low-affinity peptides.

[Current status of life support systems for cosmonauts and ways of their enhancement in near future].

The paper reviews the results of efforts undertaken so far to develop three types of life support systems: fill-and-draw and physicochemical reclamation systems for space flights of up to one year in duration, and systems for more extended missions. The authors point to the engineering and logistical issues that should be given the highest priority in the next decades.

Contractile activity of rabbit uterus at the end of pregnancy and a method for its registration.

We developed a method for synchronous registration of electrical activity of the myometrium in pregnant rabbit females and electrocardiograms of the female and fetus on a paper tape and on PC in the online mode using an original pickup for registration of intrauterine pressure in awaken animals in a natural (sitting) posture. The method causes no pregnancy complications and is adequate for evaluation of uterine contractility, female and fetal status in different variants of the experiment.

Uncommon properties of pLD105 conjugative plasmid.

Plasmid pLD105 isolated from a clinical strain of E. coli determines nitrofuran resistance due to inactivation of low-molecular-weight nitrofuran reductase subunit. pLD105 plasmid belongs to IncF.

Semiclassical coupled wave theory for TM waves in one-dimensional photonic crystals.

Semiclassical coupled wave theory is extended to waves with the electric field polarized parallel to the plane of incidence (TM waves) in one-dimensional periodic dielectric structures. Using this theory, the bandwidths and reflection/transmission characteristics of such structures, as functions of the incident wave frequency, are in good agreement with exact numerical simulations even for very high refractive index contrast.

Semiclassical coupled-wave theory and its application to TE waves in one-dimensional photonic crystals.

A semiclassical coupled-wave theory is developed for TE waves in one-dimensional periodic structures. The theory is used to calculate the bandwidths and reflection/transmission characteristics of such structures, as functions of the incident wave frequency. The results are in good agreement with exact numerical simulations for an arbitrary angle of incidence and for any achievable refractive index contrast on a period of the structure.

[Stimulation of thermoregulatory and respiratory functions with the help of EDTA and EGTA during deep hypothermia in rats].

Influence of EDTA (C10H14N2Na2O8.2H2O) and EGTA (C14H24N2O10) on physiological functions homoiothermic organisms at deep hypothermia, was studied. White rats during cooling were in special sections without rigid fixing of head and limbs.

[Effect of increased pressure of nitrogen on thermoregulation of mammals].

Consumption of oxygen in rats was studied under conditions of the gas different ambient temperatures and pressure. A dependence was revealed between the neutral temperature and the high gas pressure. Mathematical model revealed an increase oxygen consumption at an increase gas pressure.

Switching of electromagnetic waves by two-layered periodic dielectric structures.

The propagation of electromagnetic waves in two-layered periodic dielectric structures is investigated. The systematic dependence of the reflection coefficient on the parameters characterizing the structure is studied in detail. Using results of this exact analysis we investigate the influence of variation of the structure parameters on the reflection and transmission coefficients.

Green's function analysis of electromagnetic waves in two-layered periodic structures with fluctuations in thickness.

A general method for the construction of the Green's function for finite one-dimensional inhomogeneous layers is developed. Using the results of this method the exact analytical Green's function for periodic dielectric structures is found. As an example of its application, the influence of fluctuations of the widths of the basic layers on the reflection and transmission of electromagnetic waves propagating through the structure is investigated.

[Cold-induced paralysis and recovery of lung respiration and heart contractions in newborn rats (inversion of Arrhenius law for physiological functions)].

Arrest of respiration and heart activity in new-born rats aged 3-4 days and 10-11 days was shown to occur at a body temperature 6-7 degrees C and 2-3 degrees C lower than in adult rats, resp. At room temperature the body temperature of profoundly cooled rat's litter gradually increases and the functions are restored. In 3-4-day old rats, at the body temperature rising from profound cooling to 15-18 degrees C, the respiration and heart rates are 2-4-fold more than at the same temperature attained from the normal body temperature.

[The humoral immunity characteristics of women with neurotic depressions].

The levels of autoantibodies and their anti-idiotypes to proteins of nervous tissue (S100b, GFAP, MP65 and nerve growth factor) were studied in 85 women of 18-48 years of age with psychogenic neurotic depressions. It was found that the changes of the levels of autoantibodies to the proteins of nervous tissue correspond to various somatoautonomic manifestations and correlate with severity of depression, its typological variations and duration of the disease. The data obtained show a close relationship between nervous and immune systems that was expressed by some parallelism of the dynamics of the changes of both neurotic depressive symptoms and serum immunoreactivity to neuroantigens.

[Blocking of cold paralysis of physiological functions].

For more than 100-year history of studying hypothermia a rewarming of a cooled organism was always considered as the only method of restoring the cold-paralysed physiological functions and the vital activity of an overcooled organism of homoiothermal animals and humans. The paper gives the results of applying the method developed at our Laboratory, of restoring the cold-paralysed important physiological functions after a continuous cooling of rats, without rewarming the animals.