Portable Electron Microscopy for ISS and Beyond

Advances in space exploration have evolved in lockstep with key technology advances in diverse fields such as materials science, biological science, and engineering risk management. Research in these areas, where structure and physical processes come together, can proceed rapidly in part due to sophisticated ground-based analytical tools that help re-searchers develop technologies and engineering processes that push frontiers of human space exploration. Electron microscopes (EM) are an example of such a workhorse tool, lending a unique blend of strong optical scattering, high native resolution, large depth of focus, and spectroscopy via characteristic X-ray emission, providing exquisite high-magnification structural imaging and chemical analysis. Ground-based EMs have been essential in NASA research for many years. In particular, in mineralogy and petrology, EM is used to understand the origin and evolution of the solar system, particularly rocky bodies. In microbiology, EM has helped visualize the architecture of tissues and cells. In engineering/materials science, EM has been used to characterize particulate debris in air and water samples, determine pore sizes in ceramics/catalysts, understand the nature of fibers, determine composition and morphology of new and existing materials, and characterize micro-textures of vapor deposited films. EM is highly effective at investigating a wide variety of nanoscale materials/biomaterials at the core of many of NASAs inquiries. Despite exquisite optical performance and versatility, EMs are traditionally large, heavy, and have high power consumption. They are also expensive so they tend to be housed at universities and large research institutions, or at major industrial laboratory sites with support staff, supplies, and skilled operators. Since most organizations cannot support their own EM, samples are often sent to these large institutions and service centers to be imaged, at great expense and of-ten with delay of weeks to months for complex analyses. Complexity, high cost, and maintenance associated with collecting EM image data has until now severely limited fields in which EM is used. Making EM accessible outside constrained terrestrial laboratory environments will bring EMs performance and versatility to a much broader range of scientific and engineering endeavors, including in space

Flight Readiness of Mochii ISS-NL Portable Spectroscopic Electron Microscope

Electron microscopes (EMs), are workhorse tools serving diverse fields such as materials science, biological science, and engineering. Scanning EMs (SEMs) in particular enable high magnification study and pinpoint chemical analyses of structures down to the nanoscale by providing a powerful blend of strong optical scattering, high native resolution, large depth of focus, and energy-dispersive X-ray spectroscopy (EDS). Mochii is the worlds smallest production electron microscope, scheduled to travel to the International Space Station (ISS) this spring where it will serve as an ISS National Laboratory (ISSNL) microgravity facility on successful demonstration. We previously reported on progress preparing Mochii for space flight, in particular flight integration verifications and science application testing. These included standard integration testing such as electromagnetic interference and flight vibration, and extend to unique functional testing such as magnetic susceptibility and extreme analog environment testing under the sea. Presently, Mochii payload flight hardware has completed testing and was handed over to NASAs ISS payload processing facility in Houston. It will make its way to the the east coast for launch currently scheduled on Space-X CRS-20 for Mission increment 62 in March 2020

Patient-Reported Outcome for Endovascular Treatment versus Microsurgical Clipping in Aneurysmal Subarachnoid Hemorrhage

Objective Aneurysmal subarachnoid hemorrhage has a high mortality with significant impact on quality of life despite effective management strategies including endovascular treatment and/or microsurgical clipping. Although the modalities have undergone clinical comparison, they have not been evaluated on patient-reported outcomes (PROs). This study compared endovascular versus microsurgical treatment using a PRO measure. Methods We conducted a cross-sectional telephonic survey of adult patients conducted at Hamad General Hospital, Doha, Qatar between 2017 and 2019. Candidate study participants were identified from procedure logs and hospital electronic health records for endovascular treatment (N = 32) versus microsurgical clipping (N = 32) of cerebral aneurysm. The primary outcome measure was the short version of the Stroke-Specific Quality of Life (SS-QoL) measure. The secondary outcome measure was the screened clinician-reported modified Rankin Scale (mRS) for all screened patients (n = 137). Mean scores were compared for the 2 treatment groups. Results The SS-QoL mean score was 4.23 (standard deviation ± 0.77) in endovascular treatment and 4.19 ± 0.19 in surgical clipping (P = 0.90). In exploratory analysis, mean physical domain score was 3.17 ± 0.60 versus 2.98 ± 0.66 in endovascular treatment and surgical clipping groups, respectively. Mean psychosocial domain scores were 4.43 ± 0.85 versus 4.18 ± 0.0.92, respectively. In multivariable analysis, none of the clinical variables were significantly related to SS-QoL except vasospasm irrespective of intervention received. In secondary outcome analysis, modified Rankin Scale score was higher for endovascular treatment (P = 0.04). Conclusions Published evidence has supported clinical benefits of endovascular treatment for cerebral aneurysm treatment, but this study did not find any difference in PROs. Future studies of treatments should include PRO to identify potential differences from the patient's perspective.The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.Scopu

Abnormal corneal nerve morphology and brain volume in patients with schizophrenia

Neurodevelopmental and neurodegenerative pathology occur in Schizophrenia. This study compared the utility of corneal confocal microscopy (CCM), an ophthalmic imaging technique with MRI brain volumetry in quantifying neuronal pathology and its relationship to cognitive dysfunction and symptom severity in schizophrenia. Thirty-six subjects with schizophrenia and 26 controls underwent assessment of cognitive function, symptom severity, CCM and MRI brain volumetry. Subjects with schizophrenia had lower cognitive function (P ≤ 0.01), corneal nerve fiber density (CNFD), length (CNFL), branch density (CNBD), CNBD:CNFD ratio (P < 0.0001) and cingulate gyrus volume (P < 0.05) but comparable volume of whole brain (P = 0.61), cortical gray matter (P = 0.99), ventricle (P = 0.47), hippocampus (P = 0.10) and amygdala (P = 0.68). Corneal nerve measures and cingulate gyrus volume showed no association with symptom severity (P = 0.35–0.86 and P = 0.50) or cognitive function (P = 0.35–0.86 and P = 0.49). Corneal nerve measures were not associated with metabolic syndrome (P = 0.61–0.64) or diabetes (P = 0.057–0.54). The area under the ROC curve distinguishing subjects with schizophrenia from controls was 88% for CNFL, 84% for CNBD and CNBD:CNFD ratio, 79% for CNFD and 73% for the cingulate gyrus volume. This study has identified a reduction in corneal nerve fibers and cingulate gyrus volume in schizophrenia, but no association with symptom severity or cognitive dysfunction. Corneal nerve loss identified using CCM may act as a rapid non-invasive surrogate marker of neurodegeneration in patients with schizophrenia