Climate Change and Geochemistry May Explain the Finding of Marine Cyanobacteria in a Continental Saline Lake

1 Introduction Alkaline Lake Khilganta located in a steppe zone of South Siberia(N 50°42’535,E 115°06’086)is unique among adjacent lakes because of a development of a thick(up to 3 cm)cyanobacterial mat dominated

Microbial processes and factors controlling their activities in alkaline lakes of the Mongolian plateau

A striking feature of the Mongolian plateau is the wide range of air temperatures during a year,-30 to 30°C.High summer temperatures,atmospheric weathering and the arid climate lead to formation of numerous alkaline soda lakes that are covered by ice during 6–7 months per year.During the study period,the lakes had p H values between 8.1 to 10.4 and salinity between 1.8 and 360 g/L.According to chemical composition,the lakes belong to sodium carbonate,sodium chloride-carbonate and sodium sulfate-carbonate types.This paper presents the data on the water chemical composition,results of the determination of the rates of microbial processes in microbial mats and sediments in the lakes studied,and the results of a Principal Component Analysis of environmental variables and microbial activity data.Temperature was the most important factor that influenced both chemical composition and microbial activity.p H and salinity are also important factors for the microbial processes.Dark CO 2 fixation is impacted mostly by salinity and the chemical composition of the lake water.Total photosynthesis and sulfate-reduction are impacted mostly by p H.Photosynthesis is the dominant process of primary production,but the highest rate(386 mg C/(L?d)) determined in the lakes studied were 2–3 times lower than in microbial mats of lakes located in tropical zones.This can be explained by the relatively short warm period that lasts only 3–4 months per year.The highest measured rate of dark CO 2 assimilation(59.8 mg C/(L?d)) was much lower than photosynthesis.The highest rate of sulfate reduction was 60 mg S/(L?d),while that of methanogenesis was 75.6 μLСН 4 /(L?d) in the alkaline lakes of Mongolian plateau.The rate of organic matter consumption during sulfate reduction was 3–4 orders of magnitude higher than that associated with methanogenesis.

Conjugation of the Recombinant Third Domain of Human Alpha-fetoprotein with Doxorubicin Using Poly(amidoamine) Dendrimers and Study of Its Cytotoxic Activity

The recombinant third domain of alpha-fetoprotein (AFP3D) is one of the promising vectors for targeted delivery of anticancer drugs to tumor cells. AFP3D-based conjugates with various anti-tumor agents have shown specific anti-tumor activity. The content of anti-tumor drugs in the preparation could be increased by including dendrimers - highly branched nanoparticles - into a targeted delivery system. In this study, we synthesized the AFP3D conjugate with doxorubicin-loaded poly(amidoamine) (PAMAM) dendrimer nanoparticles and investigated its cytotoxic activity.

Characterization and Electrochemical Properties of Nanostructured Zr-Doped Anatase TiO_2 Tubes Synthesized by Sol–Gel Template Route

A series of nanostructured Zr-doped anatase TiO_2 tubes with the Zr/Ti molar ratio of 0.01, 0.02, 0.03, and0.09 were prepared by a sol–gel technology on a carbon fiber template. The electrochemical performance of Zr-doped anatase TiO_2 as anodes for rechargeable lithium batteries was investigated and compared with undoped titania. Tests represented that after 35-fold charge/discharge cycling at C/10 the reversible capacity of Zr-doped titania(Zr/Ti = 0.03) reaches 135 m A h g^(-1), while the capacity of undoped titania(Zr/Ti = 0) yielded only 50 m A h g^(-1). Based on the results of the physicochemical investigation, three reasons of improving electrochemical performance of Zr-doped titania were suggested. According to the scanning electron microscopy and transmission electron microscopy, Zr^(4+) doping induces a decrease in nanoparticle size, which facilitates the Li+diffusion. The Raman investigations show the more open structure of Zr-doped TiO_2 as compared to undoped titania due to changing of the unit cell parameters, that significantly affects on the reversibility of the insertion/extraction process. The electrochemical impedance spectroscopy results indicate that substitution of Zr^(4+) for Ti^(4+) into anatase TiO_2 has favorable effects on the conductivity.

Revisit to Two-Proton Radioactivity of 19Mg and Observation of Two-Proton Decay of 30Ar

An experiment aimed to investigate the two-proton(2p) decay of the previously unknown nucleus ^(30)Ar was performed at GSI. By tracking the decay products in-flight with silicon micro-strip detectors, the 2p decays of ^(30)Ar were observed for the first time. For the calibration purpose, 2p decays of ^(19)Mg were also remeasured by tracking the coincident ^(17)Ne+p+p trajectories. By comparing the measured angular p-17 Ne correlations with those obtained from the corresponding Monte Carlo simulations,the simultaneous 2p decay of ^(19)Mg ground state and the sequential 2p emission of several known excited states of ^(19)Mg were confirmed. One new excited state in ^(19)Mg and two new excited states in ^(18)Na were observed.