Size, weight and position: ion mobility spectrometry and imaging MS combined

Size, weight and position are three of the most important parameters that describe a molecule in a biological system. Ion mobility spectrometry is capable of separating molecules on the basis of their size or shape, whereas imaging mass spectrometry is an effective tool to measure the molecular weight and spatial distribution of molecules. Recent developments in both fields enabled the combination of the two technologies. As a result, ion-mobility-based imaging mass spectrometry is gaining more and more popularity as a (bio-)analytical tool enabling the determination of the size, weight and position of several molecules simultaneously on biological surfaces. This paper reviews the evolution of ion-mobility-based imaging mass spectrometry and provides examples of its application in analytical studies of biological surfaces

Сравнительная оценка экспрессии молекул главного комплекса гистосовместимости в тканях пародонта и периферической крови больных генерализованным пародонтитом

Проведено порівняльні клініко-іммунологічні аналізи стану адгезивних молекул HLA-A, B, C і HLA-DR головного комплексу гістосумісності на місцевому рівні - в тканинах пародонта і периферичної крові хворих на ГП і відповідних антигенів моноклональних антитіл T і В-лімфоцитів. Не виявлено прямого кореляційного зв’язку між клінічним проявом запалення пародонту і загальносоматичним імунним статусом, що розкриває механізми локальних Т-клітинних характеристик імунних змін і зумовлює корекцію місцевої терапії.A comparative clinical and immunological analysis of adhesion molecules HLA-A, B, C and HLA-DR major histocompatibility complex at the local level - in periodontal tissues and peripheral blood of patients with SE and related antigen antibody monoklialnyh T and B lymphocytes. There were no direct connection between korellyatsionnoy clinical manifestation of periodontal inflammation and the immune status of the somatic, that reveals the mechanisms of local T-cell characteristics of the immune changes and determines the correction of local therapy

Microscope Mode Secondary Ion Mass Spectrometry Imaging with a Timepix Detector

In-vacuum active pixel detectors enable high sensitivity, highly parallel time- and space-resolved detection of ions from complex surfaces. For the first time, a Timepix detector assembly was combined with a Secondary Ion Mass Spectrometer for microscope mode SIMS imaging. Time resolved images from various benchmark samples demonstrate the imaging capabilities of the detector system. The main advantages of the active pixel detector are the higher signal-to-noise ratio and parallel acquisition of arrival time and position. Microscope mode SIMS imaging of biomolecules is demonstrated from tissue sections with the Timepix detector

PREFERENTIAL FLOW EFFECTS ON SUBSURFACE CONTAMINANT TRANSPORT IN ALLUVIAL FLOODPLAINS

For sorbing contaminants, transport from upland areas to surface water systems is typically considered to be due to surface runoff, with negligible input from subsurface transport assumed. However, certain conditions can lead to an environment where subsurface transport to streams may be significant. The Ozark region, including parts of Oklahoma, Arkansas, and Missouri, is one such environment, characterized by cherty, gravelly soils and gravel bed streams. Previous research identified a preferential flow path (PFP) at an Ozark floodplain along the Barren Fork Creek in northeastern Oklahoma and demonstrated that even a sorbing contaminant, i.e., phosphorus, can be transported in significant quantities through the subsurface. The objective of this research was to investigate the connectivity and floodplain-scale impact of subsurface physical heterogeneity (i.e., PFPs) on contaminant transport in alluvial floodplains in the Ozarks. This research also evaluated a hypothesis that alluvial groundwater acts as a transient storage zone, providing a contaminant sink during high stream flow and a contaminant source during stream baseflow. The floodplain and PFP were mapped with two electrical resistivity imaging techniques. Low-resistivity features (i.e., less than 200 Ω-m) corresponded to topographical depressions on the floodplain surface, which were hypothesized to be relict stream channels with fine sediment (i.e., sand, silt, and clay) and gravel deposits. The mapped PFP, approximately 2 m in depth and 5 to 10 m wide, was a buried gravel bar with electrical resistivity in the range of 1000 to 5000 Ω-m. To investigate the PFP, stream, and groundwater dynamics, a constant-head trench test was installed with a conservative tracer (Rhodamine WT) injected into the PFP at approximately 85 mg/L for 1.5 h. Observation wells were installed along the PFP and throughout the floodplain. Water table elevations were recorded real-time using water level loggers, and water samples were collected throughout the experiment. Results of the experiment demonstrated that stream/aquifer interaction was spatially non-uniform due to floodplain-scale heterogeneity. Transport mechanisms included preferential movement of Rhodamine WT along the PFP, infiltration of Rhodamine WT into the alluvial groundwater system, and then transport in the alluvial system as influenced by the floodplain-scale stream/aquifer dynamics. The electrical resistivity data assisted in predicting the movement of the tracer in the direction of the mapped preferential flow pathway. Spatially variable PFPs, even in the coarse gravel subsoils, affected water level gradients and the distribution of tracer into the shallow groundwater system