Note: Performance of a novel electrostatic quadrupole doublet for nuclear microprobe application.

The newly designed and constructed electrostatic quadrupole doublet (EQD) at the University of North Texas (UNT) has achieved mass independent focusing of MeV particles to a spot size of 3.3 × 3.5 µm. The EQD is compared to the Louisiana magnetic doublet which is also in use at UNT. Characteristics such as demagnification and sensitivity to aberrations are simulated by the matrix raytracing software, propagation of rays and aberrations by matrices and compared for each focusing system. Particle induced x-ray emission (PIXE) maps of a 2000 mesh Cu grid are compared and show that both doublets produce suitable spot sizes for microprobe analysis. A coarser, 200 mesh grid and incident beams of 2 MeV H+ and O+ show the EQD to be stigmatic given common aperture sizes and lens potentials.

Authors' Reply to the Commentary in the journal of Electrophoresis regarding "The effect of simulated space radiation on the N-glycosylation of human immunoglobulin G1" by J.J. Bevelacqua and S.M.J. Mortazavi.

By reading the commentary of Bevelacqua and Mortazavi regarding our recently published paper titled as "The effect of simulated space radiation on the N-glycosylation of human immunoglobulin G1"[1], we are afraid that some of the important messaging aspects of our paper might not have been articulated adequately to be fully understandable for a wider audience, i.e., not separation scientists. First, we should clarify that complete space radiation description was not the goal of this paper. In this short communication we only intended to show the effect of simulated space radiation on the conserved N-glycosylation of IgG1 molecules with the goal to understand if they could be utilized as disease biomarkers during longer space missions, similar to that as they are currently used here on Earth, e.g. for autoimmune disease or aging markers. Therefore, no discussion was given about any biological effects either as our study only investigated the qualitative effects of proton irradiation on the N-linked carbohydrate decomposition of IgG type 1 molecules with the intent of suggesting them to be used as biomarkers during deep space travel. Radioadaptation was never an issue in our study for the reasons mentioned above.

The effect of simulated space radiation on the N-glycosylation of human immunoglobulin G1.

On a roundtrip to Mars, astronauts are expectedly exposed to an approximate amount of radiation that exceeds the lifetime limits on Earth. This elevated radiation dose is mainly due to Galactic Cosmic Rays and Solar Particle Events. Specific patterns of the N-glycosylation of human Igs have already been associated with various ailments such as autoimmune diseases, malignant transformation, chronic inflammation, and ageing. The focus of our work was to investigate the effect of low-energy proton irradiation on the IgG N-glycosylation profile with the goal if disease associated changes could be detected during space travel and not altered by space radiation. Two ionization sources were used during the experiments, a Van de Graaff generator for the irradiation of solidified hIgG samples in vacuum, and a Tandetron accelerator to irradiate hIgG samples in aqueous solution form. Structural carbohydrate analysis was accomplished by CE with laser induced fluorescent detection to determine the effects of simulated space radiation on N-glycosylation of hIgG1 samples. Our results revealed that even several thousand times higher radiation doses that of astronauts can suffer during long duration missions beyond the shielding environment of Low Earth Orbit, no changes were observed in hIgG1 N-glycosylation. Consequently, changes in N-linked carbohydrate profile of IgG1 can be used as molecular diagnostic tools in space.

Tilted pillar array fabrication by the combination of proton beam writing and soft lithography for microfluidic cell capture: Part 1 Design and feasibility.

Design, fabrication, integration, and feasibility test results of a novel microfluidic cell capture device is presented, exploiting the advantages of proton beam writing to make lithographic irradiations under multiple target tilting angles and UV lithography to easily reproduce large area structures. A cell capture device is demonstrated with a unique doubly tilted micropillar array design for cell manipulation in microfluidic applications. Tilting the pillars increased their functional surface, therefore, enhanced fluidic interaction when special bioaffinity coating was used, and improved fluid dynamic behavior regarding cell culture injection. The proposed microstructures were capable to support adequate distribution of body fluids, such as blood, spinal fluid, etc., between the inlet and outlet of the microfluidic sample reservoirs, offering advanced cell capture capability on the functionalized surfaces. The hydrodynamic characteristics of the microfluidic systems were tested with yeast cells (similar size as red blood cells) for efficient capture.