One-Year In Situ Incubation of Pyrite at the Deep Seafloor and Its Microbiological and Biogeochemical Characterizations.

In this study, we performed a year-long in situ incubation experiment on a common ferrous sulfide (Fe-S) mineral, pyrite, at the oxidative deep seafloor in the hydrothermal vent field in the Izu-Bonin arc, Japan, and characterized its microbiological and biogeochemical properties to understand the microbial alteration processes of the pyrite, focusing on Fe(II) oxidation. The microbial community analysis of the incubated pyrite showed that the domain Bacteria heavily dominated over Archaea compared with that of the ambient seawater, and Alphaproteobacteria and Gammaproteobacteria distinctively codominated at the class level. The mineralogical characterization by surface-sensitive Fe X-ray absorption near-edge structure (XANES) analysis revealed that specific Fe(III) hydroxides (schwertmannite and ferrihydrite) were locally formed at the pyrite surface as the pyrite alteration products. Based on the Fe(III) hydroxide species and proportion, we thermodynamically calculated the pH value at the pyrite surface to be pH 4.9 to 5.7, indicating that the acidic condition derived from pyrite alteration was locally formed at the surface against neutral ambient seawater. This acidic microenvironment at the pyrite surface might explain the distinct microbial communities found in our pyrite samples. Also, the acidity at the pyrite surface indicates that the abiotic Fe(II) oxidation rate was much limited at the pyrite surface kinetically, 3.9 × 103- to 1.6 × 105-fold lower than that in the ambient seawater. Moreover, nanoscale characterization of microbial biomolecules using carbon near-edge X-ray absorption fine-structure (NEXAFS) analysis showed that the sessile cells attached to pyrite excreted the acidic polysaccharide-rich extracellular polymeric substances at the pyrite surface, which can lead to the promotion of biogenic Fe(II) oxidation and pyrite alteration. IMPORTANCE Pyrite is one of the most common Fe-S minerals found in submarine hydrothermal environments. Previous studies demonstrated that the Fe-S mineral can be a suitable host for Fe(II)-oxidizing microbes in hydrothermal environments; however, the details of microbial Fe(II) oxidation processes with Fe-S mineral alteration are not well known. The spectroscopic and thermodynamic examination in the present study suggests that a moderately acidic pH condition was locally formed at the pyrite surface during pyrite alteration at the seafloor due to proton releases with Fe(II) and sulfidic S oxidations. Following previous studies, the abiotic Fe(II) oxidation rate significantly decreases with a decrease in pH, but the biotic (microbial) Fe(II) oxidation rate is not sensitive to the pH decrease. Thus, our findings clearly suggest that the pyrite surface is a unique microenvironment where abiotic Fe(II) oxidation is limited and biotic Fe(II) oxidation is more prominent than that in neutral ambient seawater.

Local Measurement of Janus Particle Cap Thickness.

Janus particles have anisotropy in surface chemistry or composition that will effect dynamics and interactions with neighboring surfaces. One specific type of Janus particle is that consisting of a native micrometer-scale particle with a cap of gold, platinum, or another metal deposited with a typical thicknesses of ∼10 nm. A key characteristic of metal-capped Janus particles prepared with glancing angle deposition is the cap thickness. The nominal thickness is usually assumed to be uniform across the cap for modeling or interpretation of data, but the vapor deposition fabrication process likely does not produce such a cap because of the particle's curvature. These nonuniformities in the cap thickness may have a profound impact on Janus particle dynamics at equilibrium and in response to external fields. Herein, we summarize an experimental technique that utilizes focused ion beam slicing, image analysis, and results for the direct and local measure of cap thickness for 5 µm polystyrene spheres with a gold cap of nominal thicknesses of 10 or 20 nm. We found the cap varied in thickness continuously along the perimeter of the particle and also that the deposition rate, varying between 0.5 and 2.0 Å/s, did not significantly alter the way in which the thickness varied. These data support the hypothesis that cap thickness of a Janus sphere will vary across the gold surface contour, while demonstrating a feasible route for direct measurement of Janus particle cap thickness.

Organofunctional Silane Modification of Aluminum-Doped Zinc Oxide Surfaces as a Route to Stabilization.

Aluminum-doped zinc oxide (AZO) is a low-temperature processed transparent conductive oxide (TCO) made of earth abundant elements; its applications are currently limited by instability to heat, moisture, and acidic conditions. We demonstrate that the application of an organofunctional silane modifier mitigates AZO degradation and explore the interplay between performance and material composition and morphology. Specifically, we evaluate degradation of bare AZO and APTES (3-aminopropyltriethoxysilane)-modified AZO in response to damp heat (DH, 85 °C, 85% relative humidity) exposure over 1000 h and then demonstrate how surface modification impacts changes in electrical and optical properties and chemical composition in one of the most thorough studies to date. Hall measurements show that the resistivity of AZO increases due to a decrease in electron mobility, with no commensurate change in carrier concentration. APTES decelerates this electrical degradation, without affecting AZO optical properties. Percent transmission and yellowness index of an ensemble of bare and modified AZO are stable upon DH exposure, but haze increases slightly for a discrete sample of modified AZO. Atomic force microscopy (AFM) and optical profilometer (OP) measurements do not show evidence of pitting or delamination after 1000 h DH exposure but indicate a slight increase in surface roughness on both the nanometer and micrometer length scales. X-ray photoelectron spectroscopy data (XPS) reveal that the surface composition of bare and silanized AZO is stable over this time frame; oxygen vacancies, as measured by XPS, are also stable with DH exposure, which, together with transmission and Hall measurements, indicate stable carrier concentrations. However, after 1500 h of DH exposure, only bare AZO shows signs of catastrophic destruction. Comparison of the data presented herein to previous reports indicates that the initial AZO composition and microstructure dictate the degradation profile. This work demonstrates that surface modification slows the bulk degradation of AZO and provides insight into how the material can be more widely used as a transparent electrode in the next generation of optoelectronic devices.

[Transpupillary laser photocoagulation of ocular fundus: history, the present, and the future]. / Transpupillyarnaya lazernaya fotokoagulyatsiya tkanei glaznogo dna: proshloe, nastoyashchee i budushchee.

The present review covers the use of chorioretinal photocoagulation, which is now a popular treatment for many diseases of the ocular fundus. The review includes a detailed 50-year history of the technology with account to both Russian and foreign achievements. The current state of the field is shown through Russian and foreign literature data. A particular emphasis is placed on subthreshold, pattern, and navigated techniques. Breakthrough solutions, such as optoacoustic monitoring, that ensure high precision of the procedure, maximum saving of tissues, and high therapeutic effectiveness are described.

[Species-specific features of tocopherol content in carnivorous mammals during autumn period].

A comparative study of the major liposoluble antioxidant, vitamin E (α-tocopherol), content was conducted in carnivorous mammals (polar fox, silver fox, raccoon dog, mink, sable) during late autumn under natural lowering of temperature. The highest vitamin E content in liver and kidney was found in polar fox and raccoon dog, obviously due to seasonal metabolic changes and ecological specialization determining the accumulation of considerable amounts of tocopherol both in polar and hibernating species. To investigate the features of vitamin E accumulation, the tocopherol loading experiment was implemented on three species (polar fox, silver fox, mink). It was shown that polar fox, as compared to silverfox and mink, exhibits a higher ability to reserve vitamin E. The established differences in tocopherol content and distribution in different species should be considered as a genetically fixed reaction to the effect of environment underlain by metabolic differences in animals with different ecological specialization. The ability of tocopherol to accumulate in tissues and organs allows considering its essential role in stabilization of the antioxidant system and ensuring thereby a seasonal cold resistance.

[Plastid stromules as specific elements of the multipurpose endoplasmic reticulum].

It is supposed, that the compromise between all groups of researchers of stromules can be reached if to accept, that an external membrane of stromules together with an external membrane of initial plastid are the specific domain of endoplasmic reticulum. Such domain co-operates with other membranes of a cell by means of membrane contact sites with free permeability for small molecules (presumably to 1.5 KDa).

[Double-component bacterial regulation systems as a target for searching new antimicrobial agents].

A review of the literature data concerning double-component bacterial regulation systems was given. The observed data concern: a) structural and functional organization based on the example of systems of the family OmpR (EnvZ/OmpR, PhoQ/PhoP), which regulate a number of processes providing adaptation to stress conditions in the environment and host body providing the virulence and biofilm formation, the cause of different human chronic infections; b) the genes and functions regulated by the double-components systems, based on the example of EnvZ/OmpR system, especially OmpR protein, and PhoQ/PhoP system. The possibilities for the searching of the double-component system protein inhibitors and their role in depressing pathogenic bacteria virulence were discussed.

[Light pollution, desynchronosis and aging: the state of problem and solutions].

The effect of different light conditions (constant illumination, light deprivation, the standard regime of lighting and natural for Northwest Russia lighting in different seasons of the annual cycle) on indicators of biological age and homeostasis, the development of age-related pathology, oncogenesis and longevity of rats was investigated. Exposure to constant light on the studied parameters was evaluated at different ages--antenatal, early and late postnatal period. The data about influences of substances and hormones of pineal gland on biomarkers of aging, homeostasis, spontaneous oncogenesis and longevity in experimental animals was obtained. It has been established that the light pollution and disturbance of photoperiod lead to desynchronosys and as a result to premature aging of the organism and age associated diseases. Ways of preventing accelerated aging were outlined.

Synthesis and Anti-HIV-1 Activity of Olean-9(11),12(13)-Dien-30-Oic Acid 3ß-(2-O-ß-D-Glucuronopyranosyl-ß-D-Glucuronopyranoside).

The glycyrrhizic acid (GA) analog olean-9(11),12(13)-dien-30-oic acid 3ß-(2-O-ß-D-glucuronopyranosyl-ß-D-glucuronopyranoside) (II) was synthesized via reduction of GA by NaBH4 in refluxing 2-PrOH:H2O with subsequent work up with HCl (5%). The cytotoxicity and antiviral activity of this glycoside against HIV-1 was studied in MT-4 cell culture. It was found that II was practically non-toxic for MT-4 cells while inhibiting accumulation of virus-specific protein p24 and RNA-dependent DNA-polymerase activity of HIV-1 reverse transcriptase (RT) (IC50 3.1 ±1.0 µg/mL).

Angle-resolved XPS analysis and characterization of monolayer and multilayer silane films for DNA coupling to silica.

We measure silane density and Sulfo-EMCS cross-linker coupling efficiency on aminosilane films by high-resolution X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) measurements. We then characterize DNA immobilization and hybridization on these films by (32)P-radiometry. We find that the silane film structure controls the efficiency of the subsequent steps toward DNA hybridization. A self-limited silane monolayer produced from 3-aminopropyldimethylethoxysilane (APDMES) provides a silane surface density of ~3 nm(-2). Thin (1 h deposition) and thick (19 h deposition) multilayer films are generated from 3-aminopropyltriethoxysilane (APTES), resulting in surfaces with increased roughness compared to the APDMES monolayer. Increased silane surface density is estimated for the 19 h APTES film, due to a ∼32% increase in surface area compared to the APDMES monolayer. High cross-linker coupling efficiencies are measured for all three silane films. DNA immobilization densities are similar for the APDMES monolayer and 1 h APTES. However, the DNA immobilization density is double for the 19 h APTES, suggesting that increased surface area allows for a higher probe attachment. The APDMES monolayer has the lowest DNA target density and hybridization efficiency. This is attributed to the steric hindrance as the random packing limit is approached for DNA double helices (dsDNA, diameter ≥ 2 nm) on a plane. The heterogeneity and roughness of the APTES films reduce this steric hindrance and allow for tighter packing of DNA double helices, resulting in higher hybridization densities and efficiencies. The low steric hindrance of the thin, one to two layer APTES film provides the highest hybridization efficiency of nearly 88%, with 0.21 dsDNA/nm(2). The XPS data also reveal water on the cross-linker-treated surface that is implicated in device aging.

[Mobile ISCR elements: structure, functions, and role in the emergence, increasing and spreading of blocks of bacterial genes of multiple antibiotic resistance].

The recently discovered method of horizontal distribution of bacterial genes with atypical ISCR sequences is reviewed using an example of drug resistance genes. The adjacent DNA segment mobilization is provided by the transposition of such elements, including rolling circle replication, formation of autonomous nonreplicable circular structures, and homological recombination. The gene distribution capacity with the ISCR elements is more significant than the capacity of transposons and integrons, thereby providing formation of groups of mobile genes, including antibiotic-resistance genes of pathogenic bacteria. The structure and functions of the ISCR elements were discussed together with their similarity and dissimilarity with the group of IS91-similar elements and their role in the emergence of blocks of bacterial genes encoding of multiple antibiotic resistance and their contribution to evolution of bacterial and plasmid genes.

[Laser cyclodestructive procedures in glaucoma treatment].

The history of development of cyclodestructive procedures is given, their advantages and disadvantages are discussed. Different techniques of laser use, relative and absolute contraindications to various laser cyclophotodestructive procedures are considered. Their potential complications and effecting mechanisms are discussed.

[Specific immunity and polymorphism of breeding plumage in pied flycatcher (Ficedula hypoleuca) males (Aves: passeriformes)].

The relationship between the type of melanin-based plumage coloration and the strength of experimentally induced immune response was studied using as an example a pied flycatcher population from the Moscow Region. The plumage of pied flycatcher males exhibits the full spectrum of transitions from contrasting black-and-white to cryptic brownish, the latter being very similar to the coloration of females. In spite of numerous studies, the nature of this polymorphism still remains vague. Unlike many other avian species with monocyclic breeding, a considerable fraction of pied flycatchers combines two energy-consuming productive processes, breeding and molt. During the main experimental treatment we activated the humoral immunity of free-living males in chick-rearing period by injection of nonpathogenic multigenic antigen (sheep red blood cells, SRBC) and estimated the strength of the immune responses after repeated captures in 6-8 days. In addition, after each capture we estimated the numbers of leucocytes (WBC), heterophil to lymphocyte ratios (H/L) and measured night time basal metabolic rates (BMR). Non-molting males of different color types showed the same immune responses. Among molting birds, the strength of the immune response was significantly higher in pale males (morphs 4-7 by Drost's scale) than in bright males with rich melanin-based coloration (morphs 2-3). This difference resulted from two opposite processes. During molting, pale males heightened the antibody titer after immunization, while bright males tended to reduce the strength of immune response. Possibly such an asymmetry in immunocompetence at the first stage of molt reflects the different life strategies of pied flycatcher males - conspicuous birds less commonly combine breeding with molt than cryptic ones.

[Influence of prenatal and postnatal illumination on male rat physiologycal parameters].

Influence of different light conditions on some physiological parameters of 3-month old male rats was studied. It was established that influence of constant light on mothers during pregnancy or on their posterity from birth leads to one-way changes of the antioxidant system, isoenzymatic spectrum of lactate dehydrogenase, blood indices and leucogram. However, the reaction is different and depends on moment of exposure. The results of testicular development of male rat indicate less sensitivity to light condition in the prenatal period compared to the postnatal ontogenesis.

[Correction of secondary hyperlipidemia in children with diabetes].

At 25 children with insulin dependent diabetes mellitus (IDDM, Type I) in a decompensation stage was estimated efficiency of correction secondary hyperlipidemia. The basic group (n = 11) along with insulinotherapy and a lipotrophic preparation (methionine) accepted probiotic Bifiform Baby in a dose 0.5 g once a day within 10 days; the comparison group (n = 14) received insulin therapy and a lipotrophic preparation. Efficiency of treatment was estimated on dynamics of lipids in serum of blood: triglycerides (TG), the total cholesterol (TH), betalipoproteides (BLP). At patients of the basic group authentic decrease TG, TH, BLP was established; at patients of group of comparison--decrease TH and BLP. Advantage of therapy secondary hyperlipidemia at children with diabetic ketoacidosis with use of Bifiform Baby consists in the elimination of the main infringement of a metabolismus of lipids in the given disease--hypertriglyceridemia.

High-resolution X-ray photoelectron spectroscopy of mixed silane monolayers for DNA attachment.

The amine density of 3-aminopropyldimethylethoxysilane (APDMES) films on silica is controlled to determine its effect on DNA probe density and subsequent DNA hybridization. The amine density is tailored by controlling the surface reaction time of (1) APDMES, or (2) n-propyldimethylchlorosilane (PDMCS, which is not amine terminated) and then reacting it with APDMES to form a mixed monolayer. High-resolution X-ray photoelectron spectroscopy (XPS) is used to quantify silane surface coverage of both pure and mixed monolayers on silica; the XPS data demonstrate control of amine density in both pure APDMES and PDMCS/APDMES mixed monolayers. A linear correlation between the atomic concentration of N atoms from the amine and Si atoms from the APDMES in pure APDMES films allows us to calculate the PDMCS/APDMES ratio in the mixed monolayers. Fluorescence from attached DNA probes and from hybridized DNA decreases as the percentage of APDMES in the mixed monolayer is decreased by dilution with PDMCS.

[Stromules-like protrusions of the membrane environment of plastids in the root cells].

The results of visualization of the stromules-like protrusions of the membrane environment of plastids in the root cells with the help of an electronic microscope are submitted. The cases of occurrence of long narrow protrusion of the external membrane with more short protrusion of the internal membrane of plastid environment inside it are discussed. The possible role of cytoskeleton and plastoskeleton in formation, accordingly, of "external" and "internal" protrusions is considered. The conclusion that the structure and functions of stromules in plant cells should be considered in unity with the structure and functions of the endoplasmic reticulum internal space is made.

[Intranuclear dynamics of chromosome 6 in nurse cells of Calliphora erythrocephala Mg. (Diptera: Calliphoridae)].

Intranuclear dynamics of chromosome 6 in nurse cell nuclei of Calliphora erythrocephala Mg. (Diptera: Calliphoridae) was studied. The 3D FISH method was used for the first time to study chromosome territories in highly polyploid nuclei whose chromosomes undergo morphological changes. A considerable change in the intranuclear location of chromosome 6 and a morphological alteration of the chromosome territory in the course of chromatin polytenization were revealed.

[Analysis of the spatial organization of the XL chromosome attachment site in nurse cell nuclei of the malaria mosquito Anopheles atroparvus].

The spatial position of the site of XL chromosome attachment to the nuclear envelope of ovarian nurse cells relative to the oocyte has been analyzed in the malaria mosquito Anopheles atroparvus. The XL chromosome attachment sites in the oocyte-nurse cell system of this species have been demonstrated to be orderly arranged, with the attachment sites in two out of three nurse cells in the same layer identically oriented relative to the oocyte.