Xenon and iodine behaviour in magmas

International audienceIodine (I) and xenon (Xe) are two key elements that trace Earth's differentiation (e.g. atmosphere formation) and dynamics (e.g. volcanism and recycling at subduction zones). Iodine and Xe abundances are linked through the decay of the extinct 129I that produced 129Xe, which is today depleted in the Earth's atmosphere compared to the composition of the solar system (i.e. chondrites). Iodine and Xe cycles and storage in the deep Earth are almost unknown, which is in large part due to the fact that their behaviour in magmas and fluids, key agents of mass transfer through planetary envelopes, are poorly known. Here, the solubility of Xe and I in melts is measured under high pressure (P) and temperature (T) conditions using large volume presses, and Xe and I behaviour in melts and fluids is monitored in situ under high P-T conditions using resistive heating diamond anvil cells combined with synchrotron x-ray fluorescence (XRF) and Raman spectroscopy. Xenon, I and H (H2O) contents were measured in quenched glasses by particle x-ray Emission (PIXE) and Elastic Recoil Detection Analysis (ERDA). Solubility, speciation and degassing processes are investigated for two different compositions: haplogranitic melt (HPG analogue for crustal melts) and basaltic melts (MORB and IAB). Experimentally measured solubilities for both elements are much higher than their natural abundances in terrestrial magmas. Xenon solubility at 3.5 GPa reaches 4.00 wt.% in HPG and 0.40 wt.% in basalts. Iodine solubility is 0.46 wt.% at 0.4 GPa on average in HPG, and reaches 1.42 wt.% in basalts at 2 GPa. The in situ Raman spectroscopic study shows that I forms I-I bonds in hydrous high P fluids/melts unlike Xe that was previously shown to oxidize in high P melts. The XRF monitoring of I and Xe partitioning between aqueous fluids and silicate melts during decompression (i.e. water degassing) shows that Xe degassing is strongly P-T dependent and can be retained in the melt at deep crust conditions, while I is totally washed out from the silicate melt by the aqueous phase. Xenon and I degassing processes are based on different mechanisms, which implies that the atmospheric isotopic signature of Xe cannot be inherited from a process involving volcanic water degassing. Instead, 129Xe depletion may originate from a separation of both elements at depth, by deep fluids, a proposition that agrees with a deep storage of Xe in mineral

Development of a Biosensor for Electrochemical Detection of Tumor-Associated Proteins in Blood Plasma of Cancer Patients by Aptamers

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.A molecular biosensor based on DNA aptamers (aptasensors) for the diagnosis of lung cancer in blood plasma samples was designed. To create the aptasensor, aptamer 17_80, obtained in the study of postoperative material, was used. The affinity and binding selectivity of the aptamer 17_80 to the lung tumor tissue was confirmed on histological sections of postmortem samples of lung tissue. Using affinity enrichment and mass spectrometry, a possible target molecular of the aptamer 17_80, vimentin, was found

Development of a Biosensor for Electrochemical Detection of Tumor-Associated Proteins in Blood Plasma of Cancer Patients by Aptamers

Текст статьи не публикуется в открытом доступе в соответствии с политикой журнала.A molecular biosensor based on DNA aptamers (aptasensors) for the diagnosis of lung cancer in blood plasma samples was designed. To create the aptasensor, aptamer 17_80, obtained in the study of postoperative material, was used. The affinity and binding selectivity of the aptamer 17_80 to the lung tumor tissue was confirmed on histological sections of postmortem samples of lung tissue. Using affinity enrichment and mass spectrometry, a possible target molecular of the aptamer 17_80, vimentin, was found

Electrochemical aptasensor for lung cancer-related protein detection in crude blood plasma samples

The development of an aptamer-based electrochemical sensor for lung cancer detection is presented in the work.A highly specific DNA-aptamer, LC-18, selected to postoperative lung cancer tissues was immobilized onto a gold microelectrode and electrochemical measurements were performed in a solution contaning the redox marker ferrocyanide/ferricyanide. As a result, the electrochemical aptasensor was able to detect cancer-related targets in crude blood plasma of lung cancer patients