An international group of researchers under the leadership of Andreas Riedo and Niels Ligterink at the University of Bern have now developed ORIGIN, a mass spectrometer which can detect and identify the smallest amounts of such traces of life. They describe the instrument in a recently published article in the specialist journal Nature Scientific Reports. Niels Ligterink from the Center for Space and Habitability (CSH) is the lead author of the international study, and co-author Andreas Riedo from the Physics Institute at the University of Bern developed the instrument in the laboratories of the space research and planetary sciences divison of the Physics Institute. Various international space agencies, particularly NASA, have already expressed interest in testing ORIGIN for future missions.

New instrument required

Since the first Mars mission “Viking” in the 1970s, humanity has been searching for traces of life on Mars using highly specialized instruments which are installed on landing platforms and rovers. In its early years, Mars was Earth-like, had a dense atmosphere and even liquid water. However, as Niels Ligterink explains, Mars lost its protective atmosphere over the course of time: “As a result of this, the surface of Mars is subjected to high solar and cosmic radiation which makes life on the surface impossible.” NASA’s “Curiosity” rover is currently examining Mars in detail but with no concrete indications of traces of life to date.

Since the discovery by the Cassini and Galileo missions of the global oceans beneath kilometers of ice layers on Jupiter’s moon Europa and Saturn’s moon Enceladus, these two bodies have increasingly become the focus of the search for extraterrestrial life for researchers. According to current knowledge, the oceans have all of the properties which are not only needed for the occurrence of life, but also which provide environments in which life can exist in the long term. NASA therefore plans to land a mission on Jupiter’s moon Europa around 2030 and take measurements on the ground. The goal: Identification of life. Co-author Prof. Dr. Peter Wurz from the Physics Institute at the University of Bern says: “Concepts which were specially developed for Mars cannot be simply applied to other bodies in our solar systembecause they are very different. New instruments with higher sensitivity and simpler and more robust analysis systems must be designed and used.”

Unprecedented measurement sensitivity for proof of life in space

ORIGIN is one such new instrument which outperforms previous space instruments many terms over in terms of its measurement sensitivty. Various international space agencies have expressed great interest in the instrument for future missions. Andreas Riedo says: “NASA has invited us to particpaite and test our instrument in the Arctic. The Artic is the optimal test environment in the context of the EUROPA LANDER mission, which should start in 2025, which will allow us to demonstrate the performance of ORIGIN.”

Amino acids are key components of life as we know it on Earth. Contemporaneous proof of certain amino acids on extraterrestrial surfaces, such as those of Europa, allow conclusions to be drawn about possible life. The measurement principle developed by the Bern-based researchers is simple. Niels Ligterink explains: “Laser pulses are directed at the surface to be examined. In the process, small amounts of material are detached, the chemical composition of which is analyzed by ORIGIN in a second step.” Andreas Riedo adds: “The compelling aspect of our technology is that no complicated sample preparation techniques, which could potentially affect the result, are required. This was one of the biggest problems on Mars until now,” says Riedo. The amino acids which have been analyzed with ORIGIN to date have a specific chemical fingerprint which allows them to be directly identified. Niels Ligterink: “To be honest, we didn’t expect that our first measurements would already be able to identify amino acids.”

The discovery of traces of past or present life on bodies in our solar system beyond the Earth is of great importance for a better understanding of the existence of life in the universe and its genesis. Andreas Riedo says: “Our new measurement technology is a real improvement on the instruments currently used on space missions. If we are taken along on a future mission, we may be able to answer one of humanity’s most fundamental questions with ORIGIN: Is there life in space?.”

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Emma R. Schachner, PhD, Associate Professor of Cell Biology & Anatomy, and Bradley Spieler, MD, Vice Chairman of Radiology Research and Associate Professor of Radiology, Internal Medicine, Urology, & Cell Biology and Anatomy at LSU Health New Orleans School of Medicine, created 3D digital models from CT scans of patients hospitalized with symptoms associated with severe acute respiratory syndrome coronavirus (SARS-CoV-2).

Three patients who were suspected of having COVID-19 underwent contrast enhanced thoracic CT when their symptoms worsened. Two had tested positive for SARS-CoV-2, but one was reverse transcription chain reaction (RT-PCR) negative. But because this patient had compelling clinical and imaging, the result was presumed to be a false negative.

“An array of RT-PCR sensitivities has been reported, ranging from 30-91%,” notes Dr. Spieler. “This may be the result of relatively lower viral loads in individuals who are asymptomatic or experience only mild symptoms when tested. Tests performed when symptoms were resolving have also resulted in false negatives, which seemed to be the result in this case.”

Given diagnostic challenges with respect to false negative results by RT-PCR, the gold standard for COVID-19 diagnostic screening, CT can be helpful in establishing this diagnosis. Importantly, these CT features can range in form and structure and appear to correlate with disease progression. This allows for 3D segmentation of the data in which lung tissue can be volumetrically quantified or airflow patterns could be modeled.

The CT scans were all segmented into 3D digital surface models using the scientific visualization program Avizo (Thermofisher Scientific) and techniques that the Schachner Lab uses for evolutionary anatomy research.

“The full effect of COVID-19 on the respiratory system remains unknown, but the 3D digital segmented models provide clinicians a new tool to evaluate the extent and distribution of the disease in one encapsulated view,” adds Spieler. “This is especially useful in the case where RT-PCR for SARS-CoV-2 is negative but there is strong clinical suspicion for COVID-19.”

To date, there haven’t been good models of what COVID is doing to the lungs. So, this project focused on the visualization of the lung damage in the 3D models as compared to previous methods that have been published — volume-rendered models and straight 2D screen shots of CT scans and radiographs.

“Previously published 3D models of lungs with COVID-19 have been created using automated volume rendering techniques,” says Dr. Schachner. “Our method is more challenging and time consuming, but results in a highly accurate and detailed anatomical model where the layers can be pulled apart, volumes quantified, and it can be 3D printed.”

The three models all show varying degrees of COVID-19 related infection in the respiratory tissues — particularly along the back of the lungs, and bottom sections. They more clearly show COVID-19-related infection in the respiratory system compared to radiographs (X-rays), CT scans, or RT-PCR testing alone.

Schachner and Spieler are now segmenting more models for a larger follow up project.

In addition to being uncomfortable, the current gold standard for COVID-19 testing requires RT-PCR, a time-consuming laboratory procedure. Because of backlogs, obtaining a result can take several days. To reduce transmission and mortality rates, healthcare systems need quick, inexpensive and easy-to-use tests. Hossam Haick, Hu Liu, Yueyin Pan and colleagues wanted to develop a nanomaterial-based sensor that could detect COVID-19 in exhaled breath, similar to a breathalyzer test for alcohol intoxication. Previous studies have shown that viruses and the cells they infect emit volatile organic compounds (VOCs) that can be exhaled in the breath.

The researchers made an array of gold nanoparticles linked to molecules that are sensitive to various VOCs. When VOCs interact with the molecules on a nanoparticle, the electrical resistance changes. The researchers trained the sensor to detect COVID-19 by using machine learning to compare the pattern of electrical resistance signals obtained from the breath of 49 confirmed COVID-19 patients with those from 58 healthy controls and 33 non-COVID lung infection patients in Wuhan, China. Each study participant blew into the device for 2-3 seconds from a distance of 1¬-2 cm. Once machine learning identified a potential COVID-19 signature, the team tested the accuracy of the device on a subset of participants. In the test set, the device showed 76% accuracy in distinguishing COVID-19 cases from controls and 95% accuracy in discriminating COVID-19 cases from lung infections. The sensor could also distinguish, with 88% accuracy, between sick and recovered COVID-19 patients. Although the test needs to be validated in more patients, it could be useful for screening large populations to determine which individuals need further testing, the researchers say.

The authors acknowledge funding from the Technion-Israel Institute of Technology.

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