Early virus identification is a key component of both patient treatment and epidemiological monitoring. In the case of influenza A virus infections, where the detection of subtypes associated with bird flu in humans could lead to a pandemic, rapid subtype-level identification is important. Surface-enhanced Raman spectroscopy coupled with machine learning can be used to rapidly detect and identify viruses in a label-free manner. As there is a range of available excitation wavelengths for performing Raman spectroscopy, we must choose the best one to permit discrimination between highly similar subtypes of a virus. We show that the spectra produced by influenza A subtypes H1N1 and H3N2 exhibit a higher degree of dissimilarity when using 785 nm excitation wavelength in comparison with 532 nm excitation wavelength. Furthermore, the cross-validated area under the curve (AUC) for identification was higher for the 785 nm excitation, reaching 0.95 as compared to 0.86 for 532 nm. Ultimately, this study suggests that exciting with a 785 nm wavelength is better able to differentiate two closely related influenza viruses and likely can extend to other closely related pathogens.
This content will become publicly available on May 22, 2025
East Asian inks are a major component of calligraphy, paintings, and prints in China, Japan, and Korea and are historically made from either pine soot or oil‐lamp soot mixed with a proteinaceous binder. Although the inks from the two different soot sources have different properties in East Asian works of art, no non‐destructive methods to differentiate them scientifically currently exist. Raman spectroscopy (RS) of carbonaceous materials is commonly used to extract information about their properties and has been applied here to East Asian inks. Soots used in making modern inks were collected from 10 sources in China and Japan and analyzed using RS. RS using 405‐, 633‐, and 785‐nm excitation has been able to differentiate pine soot from oil‐lamp soot, also called lampblack. In addition, principal component analysis (PCA) of only 785‐nm Raman spectra has been able to discriminate between two different soots used in a 19th‐century Japanese woodblock printing of
- Award ID(s):
- 1706757
- PAR ID:
- 10508895
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Journal of Raman Spectroscopy
- ISSN:
- 0377-0486
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
more » « less
-
more » « less
Abstract Atmospheric river (AR) and its impact on monsoon rainfall in East Asia are investigated by considering their month‐to‐month variations during the East Asian summer monsoon (EASM). The AR in the EASM, defined as an anomalously enhanced plume‐like water vapor transport, frequently forms over eastern China, Korea and western Japan. However, its characteristics vary from the early (June‐July) to the late (August‐September) period of the EASM. In the early EASM, AR is typically characterized by a quasi‐stationary monsoon southwesterly along the northern boundary of the western North Pacific subtropical high (WNPSH), which is further intensified by a migrating extratropical cyclone in the north. In contrast, the late‐EASM AR, which is less frequent than the early EASM AR, is primarily organized by a migrating extratropical cyclone. The quasi‐stationary monsoon southwesterly is less influential as the northern boundary of the WNPSH shifts northward, being decoupled from the subtropical ocean. Both the early‐ and late‐EASM ARs contribute substantially to monsoon rainfall, especially to heavy rainfall events. In the early EASM, 35%–70% of total rainfall amount and 60%–80% of heavy rainfall events in eastern China, Korea and western Japan are associated with AR. Although weakened, AR‐related rainfall is still significant in the late EASM in Korea and western Japan. These results indicate that AR is a key ingredient of EASM precipitation and its subseasonal variations should be taken into account to better understand and predict AR‐related extreme precipitation in East Asia.
-
The East Asian VLBI Network (EAVN) is an international VLBI facility in East Asia and is operated under mutual collaboration between East Asian countries, as well as part of Southeast Asian and European countries. EAVN currently consists of 16 radio telescopes and three correlators located in China, Japan, and Korea, and is operated mainly at three frequency bands, 6.7, 22, and 43 GHz with the longest baseline length of 5078 km, resulting in the highest angular resolution of 0.28 milliarcseconds at 43 GHz. One of distinct capabilities of EAVN is multi-frequency simultaneous data reception at nine telescopes, which enable us to employ the frequency phase transfer technique to obtain better sensitivity at higher observing frequencies. EAVN started its open-use program in the second half of 2018, providing a total observing time of more than 1100 h in a year. EAVN fills geographical gap in global VLBI array, resulting in enabling us to conduct contiguous high-resolution VLBI observations. EAVN has produced various scientific accomplishments especially in observations toward active galactic nuclei, evolved stars, and star-forming regions. These activities motivate us to initiate launch of the ’Global VLBI Alliance’ to provide an opportunity of VLBI observation with the longest baselines on the earth.more » « less
-
more » « less
Abstract Vibrational spectroscopy is a very suitable tool for investigating the plant cell wall in situ with almost no sample preparation. The structural information of all different constituents is contained in a single spectrum. Interpretation therefore heavily relies on reference spectra and understanding of the vibrational behavior of the components under study. For the first time, we show infrared (IR) and Raman spectra of dibenzodioxocin (DBDO), an important lignin substructure. A detailed vibrational assignment of the molecule, based on quantum chemical computations, is given in the Supporting Information; the main results are found in the paper. Furthermore, we show IR and Raman spectra of synthetic guaiacyl lignin (dehydrogenation polymer—G‐DHP). Raman spectra of DBDO and G‐DHP both differ with respect to the excitation wavelength and therefore reveal different features of the substructure/polymer. This study confirms the idea previously put forward that Raman at 532 nm selectively probes end groups of lignin, whereas Raman at 785 nm and IR seem to represent the majority of lignin substructures.
-
more » « less
Abstract Soot particles form during combustion of carbonaceous materials and impact climate and air quality. When freshly emitted, they are typically fractal-like aggregates. After atmospheric aging, they can act as cloud condensation nuclei, and water condensation or evaporation restructure them to more compact aggregates, affecting their optical, aerodynamic, and surface properties. Here we survey the morphology of ambient soot particles from various locations and different environmental and aging conditions. We used electron microscopy and show extensive soot compaction after cloud processing. We further performed laboratory experiments to simulate atmospheric cloud processing under controlled conditions. We find that soot particles sampled after evaporating the cloud droplets, are significantly more compact than freshly emitted and interstitial soot, confirming that cloud processing, not just exposure to high humidity, compacts soot. Our findings have implications for how the radiative, surface, and aerodynamic properties, and the fate of soot particles are represented in numerical models.
