Ⅲ-5

Life, Earth andPlanetary Sciences

BL4UⅢ -5. Life, Earth and Planetary Sciences

BL3U

Measurement and Assignment of X-ray Absorption Spectra of Lipid Bilayer
Membranes in Aqueous Solutions
1

R. Tero1, W.-Z. Goh1 and M. Nagasaka2

Toyohashi University of Technology, Toyohashi 441-8580, Japan
2
Institute for Molecular Science, Okazaki 444-8585, JapanThe lipid bilayer is a self-assembled structure ofamphiphilic lipid molecules and is the fundamental
structure of biomembranes such as cell membranes.
Internal structures of lipid bilayers, such as twodimensional domains and hydrophobic thickness, andphysical properties affect the transportation of materials,
information, and energy through the biomembranes. All
these physiological reactions proceed in the presence ofions. Ions in the aqueous solution significantly influence
to these structures and properties of lipid bilayers.
Phosphatidylcholine (PC) is the most abundant lipid ofeukaryotic cell membranes. Cations bind to thephosphate and carbonyl groups of PC. However, affinityof cations to PC, and also other lipids, are still
controversy especially in the fields of theoreticalsimulations [1]. We aim to determine the binding affinityof cations to lipids in aqueous solutions experimentally,by means of X-ray absorption spectroscopy (XAS) [2, 3].
Supported lipid bilayers (SLBs) of dioleoyl-PC(DOPC),
dioctadecenyl-PC(dietherPC),anddigalactosyldiacylglycerol (DGDG) were formed on
the Si3N4 membranes of the XAS flow cell [2] by thevesicle fusion method. We prepared SLBs with few
residual vesicles as shown in Fig. 1. Fluorescencerecovery after photobleaching observation showedthat fluid and continuous SLB covered the whole Si3N4
membrane surface. O-K edge XAS spectra of the
Si3N4 membrane before and after formation of SLB
were obtained in a buffer solution (NaCl 100 mM,
HEPES 25 mM/ pH 7.4 NaOH) which thickness wascontrolled to be ~100 nm. The XAS spectrum of the
Si3N4 membrane without SLB was subtracted fromthat with SLB.
The O-K-edge spectrum of DOPC, which has
phosphate and carbonyl groups on its headgroup,
appeared at 531 - 533 eV (Fig. 2a, black dotted line).
Removing residual vesicles from SLBs drastically
improved the S/N ratio [2]. Figure 2b shows the XAS
spectrum of dietherPC, which have only the phosphategroup. We attributed the components of the dietherPC
spectrum to 1s→π* transitions of P=O and P-O-Na at
531.5 eV and 532.3 eV, respectively, based on the
inner shell calculation. We assigned the single
component at 532.0 eV in the DGDG spectrum (Fig.
2c) to C=O. Based on these assignments, we
deconvoluted the DOPC spectrum to P=O, C=O, and
P-O-Na (Fig. 2a, dashed lines).
In conclusion, we obtained O-K edge XAS spectraof SLBs in an aqueous solution with a sufficient S/Nratio to identify the components in the spectra. We will

investigate the effects of the cation concentration andspecies on the XAS components in SLBs.

Fig. 1. Fluorescence image of DOPC-SLB on the the
Si3N4 membranes of the XAS flow cell.

a

b

c

Fig. 2. O K-edge spectra of (a) DOPC-, (b)dietherPC-, and (c) DGDG-SLBs. Black dotted curves
show raw data. Dashed curves and red solid curves
show deconvoluted components and their summation,
respectively.
[1] T. B. Woolf, Biophys. J. 104 (2013) 746; A. Catte,
Phys. Chem. Chem. Phys. 18 (2016) 32560.
[2] M. Nagasaka, H. Yuzawa, T. Horigome, and N.
Kosugi, J. Electron Spectros. Relat. Phenomena 224(2018) 93.
[3] R. Tero, W.-Z. Goh and M. Nagasaka, UVSOR
Activity Report 2019 47 (2020) 145.

129
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Ⅲ -5. Life,BL4U
Earth and Planetary Sciences

BL4U

Improvement of Molecular Mapping for Thin Sections of Isolated
Mammalian Nuclei Embedded in Resin Using STXM
A. Ito1, K. Shinohara2, A. Matsuura3, S. Toné4, M. Torigata1, K. Tohya5, H. Yuzawa6
and T. Ohigashi6,7

1School of Engineering, Tokai University, Hiratsuka 259-1292, Japan
Graduate School of Health Sciences, Fujita Health University, Toyoake 470-1192, Japan
3
Research Integrity Office, Fujita Health University, Toyoake 470-1192, Japan
4
School of Science and Engineering, Tokyo Denki University, Hatoyama 350-0394, Japan
5
Kansai University of Health Sciences, Kumatori-cho 590-0482, Japan
6
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
7
School of Physical Sciences, The Graduate University for Advanced Studies, , SOKENDAI, Okazaki 444-8585, Japan2

Ⅲ- 5

Spectromicroscopy using a scanning transmission
X-ray microscope (STXM) has been widely accepted
as a useful tool to visualize molecular distribution in
specimens. Using STXM installed at BL4U, we havebeen developing an image processing procedure forthe quantitative mapping of biomolecules, andsuccessfully applied to the distribution of nucleic acids(DNA and RNA) and proteins such as histone andbovine serum albumin (BSA) in biological specimens
using combined NEXAFS at the C, N and O-K
absorption edges [1-3].
In continuing effort to obtain molecular distributionof thick biological specimen, we used thin-sectioned
specimen to ensure sufficient transmitted X-ray
photons [4]. However, the morphology of thespecimen was not properly imaged to identify the inner
structure of the nucleus. In the present study, we tried
the following issues to explore a proper analysis
procedure for molecular distributions in isolated
mammalian nuclei embedded in agarose and resin: 1)
the sectioning method to attain thinner specimen withhigh quality and 2) analytical procedure to obtain mapsof biological molecules in the presence of agarose andorganic resin.
Isolated nuclei from human HeLa S3 cells were
fixed with glutaraldehyde followed by mixing withagarose to confine to limited volume, and thenembedded in Quetol-812 epoxy resin with curing
agents and a curing promoter as described previously[4]. The resin section of 0.2 m thickness was madeby a microtome with a diamond knife in place of a
glass knife used before. The section was attacheddirectly on an address mesh (HF-15, Nissin EM)
without any supporting membrane such as collodion to
avoid the complexity of analytical procedure by theadditional organic compound.
We applied our method to calculate the distributionsof nucleic acids and proteins [3] with somemodifications for the resin-embedded section
specimens. In order to estimate the stack files ofagarose and resin, we adopted an iteration procedure:First, the tentative stack files of agarose and resin wereobtained with the SVD (Singular Value
Decomposition) method applied to the observed datawith the spectra for nucleic acids, proteins, agaroseand resin. After subtracting stack files of agarose andresin, residual stack files including nucleic acids andproteins were calculated by our method [3]. The stackfiles of these biomolecules were used to obtain thesecondly approximated stack files of agarose and resin.
By using thus obtained stack files of agarose and resin,
the improved stack files of biomolecules were
calculated. The above procedure was repeated.
Figure 1 shows the X-ray image of the isolated
nucleus at 398 eV (panel a), where the dense area inthe center of nucleus is probably assigned as anucleolus. The quality of the image was much better
than the previous one [4]. Molecular images of DNA,
RNA, and histone were shown in the panel b, c and d,respectively. DNA and histone seem to bepreferentially co-localized in the nucleolus, while
RNA had significant distribution all over the nucleus.
(a)

(b)

(c)

(d)

Fig. 1. Isolated nucleus of human HeLa S3 cell.
(a) X-ray image at 398 eV, (b-d) Molecular distributionof DNA, RNA and histone.
[1] K. Shinohara et al., Ultramicrosc. 194 (2018) 1.
[2] K. Shinohara et al., J. X-Ray Sci. Technol. 26 (2018)877.
[3] K. Shinohara et al., Cells 8 (2019) 8.
[4] A. Ito et al., UVSOR Activity Report 2019 47 (2020)
148.

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Ⅲ -5. Life, Earth and Planetary Sciences

BL4U

Nano-Structural and Chemical Analysis of Structural Color on an Elytronof a Jewel Beetle
2

T. Ohigashi1,2 and H. Yuzawa1

UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
School of Physical Sciences, The Graduate University for Advanced Studies, SOKENDAI, Okazaki 444-8585, Japan
1

Structural color is not a real color but an opticalphenomenon such as reflection, diffraction andinterference. Some kinds of animals, birds, clam shells,
squids and insects, have the structural color caused byfine periodic structures, whose size is nearlywavelength of visible light. The structural color often
shows shiny and metallic color and is different frompigment color. Therefore, the animals with the structural
color are sometimes treated as jewelry. A jewel beetle,
Chrysochroa fulgidissima (Fig. 1), shows structural
color, green with a red line, on its elytron and is used as
ornaments on Tamamushi no zushi as a national treasure
in Japan (made in 7th c.). On the other hand, thestructural color is attracting the attention in industries as
an ecological painting method because the structural
color does not use pigments. In this research, the finestructures of the elytron of the jewel beetle are analyzed
to understand origin of the structural color. Then,scanning transmission X-ray microscopy (STXM) is a
powerful tool to analyze chemical and morphologicalinformation of the sample with high spatial resolution.
As a sample preparation, the elytron of the jewel
beetle, which was captured in Ishikawa prefecture, isembedded in NER-814 epoxy resin (Nisshin EM Co.
Ltd.) without chemical fixation and staining. Thin
sections of thickness of 150 nm were cut by using
ultra-microtome and set on a TEM grid with a support
membrane. An energy stack of surface of the elytron
with the embedded resin, was acquired with C 1s
regime (280 ~ 300 eV). Then, dwell time was 3 ms andscanning pitch was 30 nm step for each pixel,
respectively. A STXM images (transferred as opticaldensity) at 282, 286, 288 and 300 eV in X-ray energy
and localized X-ray absorption spectra (XAS) are
shown in Fig. 2. Positions of the XAS spectra are
indicated in Fig. 2(b) as corresponded colors. The
multilayers can be clearly distinguished only in a smallenergy region, from 285 to 287 eV and is probably 14
layers. A top layer, which decides color of the elytron(orange in Fig. 2(b)), shows the lowest optical density
in the observed region [1]. XAS of the darker layer(pink) is almost coincident with a substrate of theelytron (green). Therefore, the brighter layers (blue)
with different chemical state are considered to beformed on the substrate layer during metamorphosis.
From comparison of optical density for the excitation
to continuum level between the two layers, differenceof density is ~6%. Even though this difference is small,the pair of the layers works as a multilayer to form
structural color. For the next step, polarization ofmolecules of the elytron will be studied [2].

Fig. 1. Photo of a jewel beetle, Chrysochroa fulgidissima
(a)

(b)

(c)

(d)

Elytron

Resin
(e)

Ⅲ- 5

Fig. 2. Optical density images at X-ray energies of (a)282, (b) 286, (c) 288 and (d) 300 eV and (e) localized
X-ray absorption spectra of the elytron of the jewel
beetle.
[1] S. Yoshioka, S. Kinoshita, H. Iida and T. Hariyama,
J. Phys. Soc. Jpn., 81 (2012) 054801.
[2]T. Ohigashi, M. Nagasaka, T. Horigome, N. Kosugi,
S. M. Rosendahl and A. P. Hitchcock, AIP Conf. Proc.,
1741 (2016) 050002.

131
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Earth and Planetary Sciences

BL4U

Analysis of 3D Structure of Extraterrestrial Organic Materials Using
Combination of STXM-NEXAFS and SR Nano-tomography
M. Uesugi1, M. Ito2, K. Tomioka2, Y. Kodama3, T. Ohigashi 4,5 and H. Yuzawa4

Japan synchrotron radiation research institute (JASRI/SPring-8), Sayo 679-5198, Japan
Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science Technology (JAMSTEC),
Nankoku 783-8502, Japan
3
Marine Works Japan Ltd., Yokosuka 237-0063, Japan
4
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
5
School of Physical Sciences, The Graduate University for Advanced Studies, SOKENDAI, Okazaki 444-8585, Japan
1

2

Ⅲ- 5

Unique structure of organic compounds inextraterrestrial materials, spherical in sub-µm radiusand sometime accompanying with hollow structure, isconsidered to be informative about their origin andevolutional history [1,2]. In previous studies, most ofsuch globules, called hollow organic nano-globules,
were found in insoluble organic matter (IOM), which
was extracted as residual of acid treatment of meteorites,
to remove rocky materials. Content of organic matter inmeteorites is up to 2 % for carbonaceous chondrite, and
it is difficult to determine the organic globules in rocky
meteorites by in situ analysis in previous studies. Thus,
analyzing organic matters in IOM seems to bereasonable for previous studies.
However, organic materials were damaged andaveraged, and their nature was lost by acid treatmentof meteorites. For example, origin of hollow structureis uncertain, because materials inside the globule
would lost during the acid treatment. Molecular
structure is also changed due to averaging.
Recently, we obtained the distribution of organic
component by in situ observation of ultrathin sectionsof meteorites, using scanning transmission x-ray
microscopy and near edge x-ray absorption finestructure (STXM-NEXAFS) analysis, equipped at
BL4U of UVSOR in previous studies [3]. The organic
globules distribute widely in meteorites, and their
number density was much higher than expected before,
and reduced due to aqueous alteration.
In this experiment, we aim to obtain 3D shape andstructure of the organic globules, using in situ
observation with combination of the high resolution(HR) nano tomography developed at SPring-8, andSTXM-NEXAFS. Pixel size of HR-nano tomography at
SPring-8 is around 10 nm, and is enough to resolve theorganic globules, although it is difficult to observe
carbonaceous materials inside the rocky material due tolarge difference of linear attenuation coefficient (rocky
material: 200 - 500 cm-1, carbonaceous materials: 10 20 cm-1). In this study, we determined position of
spherical holes in meteoritic samples using in HR-nanotomography at first. Then an ultrathin section around thelargest hole was extracted by Focused ion beam (FIB).
Figure shows mapping of C-NEXAFS of the ultrathin
section extracted from A 12169 (CM) meteorite. Itshows multiple small object, which shows organic

globules. Unfortunately, the globules were very small,less than 100 nm, and could not resolve even by HR
nano tomography. Although we tried to make anultrathin section of the largest globules observed in HRnano tomography, FIB fabrication with accuracy lessthan a micron meter was failed in this case.
In future work, we plan to improve accuracy of the
FIB work. By putting marks on the surface of sample
using FIB, we can determine the position of the largest
globule in the sample with higher accuracy. In addition,
The thin section was deformed and tilted slightly
during thinning of the sample. Then objective organic
globule could not be included in the thin section. We
can fix the problem by holding both sides of thesection by FIB grid.

Fig. 1. (a) mapping of intensity of carbon absorption(b) mapping with 3 phases blue: matrix, red: organic
globules, green: carbonate. Some of tiny spots of highcarbon absorption in (a) are coupled with red area of(b), suggesting that they are organic globules. However,their size is less than 100 nm and could not resolve by
HR-nano tomography, in this time.

[1] L.A. Garvie, P. R. Buseck Earth. Planet. Sci. Lett.
224 (2004) 431[2] T. Matsumoto et al., Geochimi. Cosmochimi. Acta
116 (2013) 84.
[3] M. Uesugi et al., JpGU meeting, abstract (2019).

132
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Ⅲ -5. Life, Earth and Planetary Sciences

BL4U

Assessing the Debris Generated by the Small Carry-on Impactor Operated
from the Hayabusa2 Mission
M. Ito1, Y. Takano2, Y. Kebukawa3, T. Ohigashi4, M. Matsuoka5, K. Kiryu3, M. Uesugi6,
T. Nakamura7, H. Yuzawa4, K. Yamada8, H. Naraoka9, T. Yada5, M. Abe5, M. Hayakawa5,
T. Saiki5, S. Tachibana5,10 and Hayabusa2 Project Team
Kochi Institute for Core Sample Research, JAMSTEC, Nankoku 783-8502, Japan
2
Biogeochemistry Program, JAMSTEC, Yokosuka 237-0061, Japan
3
Yokohama National University, Yokohama 240-8501, Japan
4
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
5
ISAS-JAXA, Sagamihara 252-5210, Japan
6
JASRI/SPring-8, Sayo-cho 679-5198, Japan
7
Tohoku University, Sendai 980-8577, Japan
8
Tokyo Institute of Technology, Yokohama 226-0026, Japan
9
Kyushu University, Fukuoka 819-0395, Japan
10
University of Tokyo, Tokyo 113-0033, Japan
1

C=O: 286.5eV

C(=O)O: 288.8eV

1Aliphatic C: 287.5eV

1.2

Aromatic C: 285.2eV

the Raman D and G bands, and the H, C, and N isotopic
compositions and their spatial distributions. The
STXM–XANES results (Fig. 1) provided the molecularnature of these highly aromatic materials, which was
supported by results from TD–GC/MS. These results
suggest that it is possible to distinguish either Ryugu
samples or SCI materials as potential contaminants in asample container by using proper combinations ofanalytical techniques. This assessment provides
information useful for the analysis of the Ryugu
asteroidal samples.

0.8

Ⅲ- 5

0.6

0.4

0.2

0

Graphene structure: 291.7eV

Normalized Opticalat 292 eV (a.u.)
Opticaldensity
Density (a.u.)

The JAXA planetary exploration mission Hayabusa2(to the near-Earth C-type asteroid (162173) Ryugu) is acombination of an asteroidal sample-return mission anddetailed spectroscopic observations designed to
improve our understanding of Solar System evolution
from the point of view of organics and water (as hydrous
minerals). The Hayabusa2 spacecraft is to haveobtained Ryugu samples successfully (with a total
amount of ~ 5.4 g) from surface and subsurface regions[1]. To obtain fresh subsurface samples from the Ryugu
asteroid, a small carry-on impactor (SCI) was used togenerate an artificial crater on the surface (e.g., [2,3]).
Since very-high-explosive energy was required for thecratering operation of the Hayabusa2 mission, the SCI
system contained HMX (the high-melting-point
explosive cyclotetramethylenetetranitramine, C4H8N8O8)
and other combustion chemicals. HMX is a typical highexplosive that is used to produce a momentary driving
force (e.g., [4]).
Because these materials may be possible contaminantsin the subsurface samples, they must be investigated prior
to analysis of the Ryugu samples. They may have been
scattered around the surface of the Ryugu asteroid,
including at the second touchdown site, and then havebeen collected into the sample container together with theasteroidal subsurface samples during touchdown
sampling. We therefore set up an engineering model ofthe SCI experiment using an HMX mixture containing
HTPB, IDP, and IPDI in an Ar atmosphere at ambient
temperature and pressure in a closed system.
In this work, we report chemical and isotopic studiesof the carbonaceous-based explosion products inaddition to those presented by [5]. We used both nondestructive and destructive analytical techniques to
identify the chemical nature of the materials. From
SEM–EDS, we found the materials to be composed
mainly of carbon, nitrogen, and oxygen, with adetectable amount of metals. Suitable parameters for
identifying these materials are a FTIR peak at 1520
cm−1, low reflectance and gentle red slope of FTIR
spectrum compared with a Murchison CM2 chondrite,

Murchison (Codyet al., 2008)-0.2

EnergyEnergy (eV)(eV)

Fig. 1. Carbon-XANES of carbonaceous grains. Solidline is average of measured spectra together with
spectrum of Murchison IOM (dotted line [6]). Grey area
is a range of maximum and minimum absorptions
observed among all spectra of each measurement.
[1] T. Yada et al., 52nd LPSC (2021) LPI Contrib. No.
2548.
[2] S. Tachibana et al., Geochem. J. 48 (2014) 571.
[3] M. Arakawa et al., Science 368 (2020) 67.
[4] P.A. Snyder et al., Org. Mass Spectrom. 26 (1991)
1109.
[5] Y. Takano et al., Earth Planets Space. 72 (2020) 97.
[6] G.D. Cody et al., EPSL 272 (2008) 446.

133
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Earth and Planetary Sciences

BL4U

Penetration of Redox-Sensitive Nanocarriers in Human Skin Ex Vivo
G. Germer1, T. Ohigashi2, H. Yuzawa2, K. Rajes3, R. Haag3, F. Rancan4, A. Vogt4 and E. Rühl1
Physical Chemistry, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
3
Organic Chemistry, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
4
Charité Universitätsmedizin, 10117 Berlin, Germany
1

2

Ⅲ- 5

Redox-sensitive nanocarriers transporting drugs
into human skin have been investigated. The goal ofthis research is to use local changes in the redox stateof inflamed skin for controlled drug release. Thisrequires redox-sensitive nanocarriers transporting the
drugs over the skin barrier, which have recently beencharacterized by in vitro and ex vivo studies [1]. These
core-multishell nanocarriers (CMS) contain dendritic
architectures with sizes below 20 nm. Key is redoxsensitive sites that can lead upon oxidation to changes
in local polarity of the sulfur sites (osCMS) or upon
reduction to the cleavage of disulfides (rsCMS). In afirst step skin penetration of these redox-sensitive
nanocarriers has been investigated by scanningtransmission X-ray microscopy (STXM). The challengeof these studies was the selective probing of thenanocarriers, since there is no distinct chemical shiftcompared to the majority species contained in the
EPON fixed human skin samples. This required theuse of a recently developed procedure of data
reduction by singular value decomposition [2].
The present studies on human skin ex vivo consider
changes induced by the topically applied oxidizer dibenzoyl peroxide (DBPO, 40 mg/mL dissolved in a 1:1
mixture of acetone/propyl myristate), which wasapplied to one half of the samples for 16 h prior to
topical application of rapamycin-loaded nanocarriers(rapamycin: C51H79NO13, M = 914.13 g/mol). The
nanocarrier samples (rsCMS (5 mg/mL, rapamycin
loading: 2.7 %); osCMS (5 mg/mL) 0.5 % rapamycin
loading) were formulated in HEC gel and 40 L of thisformulation were topically applied for 10, 100, and1000 min to the skin samples, respectively. The final
drug concentrations were 1 g/cm2 (osCMS) and 5.4
g/cm2 (rsCMS), respectively. The experiments were
performed at the BL4U beamline of UVSOR III. They
mostly rely on scanning of the photon energy in the O
1s regime (520 – 565 eV), allowing for the acquisitionof stacks of images by concentrating on the stratum
corneum, the top horny layer of skin. Selected results
are shown in Fig. 1, where a comparison is madebetween a skin sample initially not exposed to DBPO
(A) and another one with pretreatment (B). The skinsamples were subsequently exposed for 1000 min to
drug-loaded rsCMS. The top of each plot shows (a) an
X-ray micrograph recorded at 532.04 eV. The skinsurface is located at the right hand side of eachmicrograph. Clearly, the stratum corneum (SC) with
its layered structure is visible besides the viableepidermis (VE). The spatial distribution of rsCMS isshown in (b). Less nanocarriers are found in the nonpretreated skin sample (A), which indicates thatDBPO enhances the skin penetration of thenanocarriers. This becomes clearly visible from theintegrated rsCMS signals as a function of depth. In thecase of the not pre-treated skin sample only weakintensity is observed, whereas for the DBPO-treatedsample (B) shows an enhanced rsCMS concentration.
Integrations also show that the maxima of the local
rsCMS concentration are correlated with narrow
regions that are assigned to the lipid regions between
the corneocytes. This is similar to earlier work on
CMS nanocarriers that were not redox-sensitive [3].
Note that the present results could only be derived bysingular value decomposition derived from data stacks
containing the full spectral information in each pixelof the micrographs, whereas the previously used pairsof photon energies for probing the nanocarriers (cf.
[3]) did not yield reliable results. Furthermore, thelocal rapamycin concentration was too low in thepresent samples to be detected. Subsequent work is
required with enhanced drug loading to probe theredox-triggered drug release.

Fig. 1. Results from STXM of the top skin layers of
fixed human skin without (A) and with (B) primary
treatment with DBPO for 16 h followed by 1000 min
exposure to reduction-sensitive nanocarriers (rsCMS):(a) X-ray scanning micrograph recorded at 532.04 eV;(b) spatial distribution of rsCMS; (c) integrated
concentration of rsCMS.
[1] K. Rajes et al., Pharmaceutics 13 (2021) 37; K.
Rajes et al., Biomater. Sci. Engin., accepted (2021).
[2] G. Germer et al., ACS Omega, accepted (2021).
[3] K. Yamamoto et al., J. Control. Release 242 (2016)
64.

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Chemical Mapping of Particulate Matter from a Marine Test-bed Engine
with Varying Sulfur Content Fuels and a Laboratory Wet-Scrubber
X. Kong1, L. F. E. D. Santos1, J. Noda2, T. Ohigashi3, K. Salo4 and E. Thomson1

Department of Chemistry and Molecular Biology, University of Gothenburg, 412 96 Gothenburg, Sweden
2
School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu 069-8501, Japan
3
UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki 444-8585, Japan
4
Maritime Environment, Shipping and Marine Technology, Chalmers University of Technology, SE-412 96
Gothenburg, Sweden
1

The marine shipping sector remains a large source ofanthropogenic particle emissions [1]. In order to reduce
particle emissions from ships, the international
maritime organization (IMO) has implemented
regulations that offer ship operators two primary
options for compliance. They can either use marine low
sulfur content fuels or high sulfur content fuels in
conjunction with wet scrubbers as exhaust abatement
system [2]. It is of large interest to investigate how bothcompliance measures affect physicochemical propertiesof exhaust particles and thus their potential role(s)within the climate system.
In June 2019 laboratory measurements investigating
the effects of fuel sulfur content (FSC) and wet
scrubbing on the droplet forming potential of exhaust
particles from a marine diesel engine were performed
using a cloud condensation nuclei counter (CCNC,DMT Inc.). Three different marine distillate fuels
including a high sulfur content fuel, heavy gas oil(HGO), with a FSC of 0.86 wt % and two IMO
compliant fuels with a FSC of < 0.003 wt %, marine gas
oil (MGO) and hydrotreated vegetable oil (HVO), wereused in a four-stroke marine test-bed engine. HGO wasalso used in conjunction with a laboratory wet scrubber
which itself was operated using both fresh as well as
seawater. While a reduction in FSC decreased the abilityof the exhaust particles to act as CCN, wet scrubbing
facilitated droplet formation significantly. Figure 1
shows the critical supersaturations, i.e., thesupersaturations needed to activate particles into cloud
droplets, of exhaust particles for different mobility
diameters.
STXM measurements of exhaust particles collectedduring a second campaign in 2020 helped to identify
chemical information (e.g., functional groups) of theparticles, which indicates the mechanism causing thedifferences observed in CCN activity. The STXM
results presented in this study were obtained at the
BL4U beamline at UVSOR.
Figure 2 shows C K-edge NEXAFS spectra of 4 cases,
i.e., HGO (2 samples), MGO, seawater and freshwater
scrubbing cases. Interestingly, the two HGO andseawater scrubbing cases show almost identical spectra,
and the MGO and freshwater scrubbing cases are
similar in line shapes. This indicates the different
organic species and abundance of these 4 cases. In
addition to the carbon edge, we also acquired N K-edge,
S L-edge, O K-edge and Cl L-edge spectra. Further

analysis of this STXM dataset and comparison with gas(e.g., SO2) and particle emission results is currently
ongoing. A manuscript is in preparation.

Fig. 1. Critical supersaturations measured for exhaust
particles of three different mobility diameters. The
colors represent the different fuel types, “Fresh” and“Sea” designate wet scrubbed exhaust particles using
fresh and seawater, respectively.

Fig. 2. Carbon K-edge NEXAFS spectra of sampled
particles from HGO, MGO, seawater scrubber andfreshwater scrubber cases.
[1] N. Kuittinen et al., Environ. Sci. Technol. 55, 1(2021)129.
[2] IMO, Resolution MEPC.176(58) (Revised MARPOL
Annex VI), 2008.

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Earth and Planetary Sciences

BL5B

Study on Reflectance Characteristics of Mirror-polished Meteorite
Fragments in the EUV Region
Y. Suzuki1, K. Yoshioka1,2, M. Kuwabara3, S. Nishimura1 and T. Kosugi2

Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo,
Tokyo 113-0033, Japan2
Department of Complexity Science and Engineering, Graduate School of Frontier Sciences, The University of Tokyo,
Kashiwa 277-8561, Japan
3
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara 252-5210, Japan1

Ⅲ- 5

We study the transition of the reflection spectrum in
the UV region when the meteorites are exposed tosolar UV for a long time. In preparation for themeasurement of meteorites, we, in this time, measured
the reflectance of mirrors with higher reflectance,since it is easier to be measured. The principle ofreflectance measurement, such as decreasing higherorder rays and the design of jigs, is the same formeteorites and mirrors. These mirrors are also to be
used for the Hydrogen Imager (HI) onboard Comet
Interceptor (CI) mission launched in 2028. In thisexperiment, the transmittance of filters used for thesame mission was also measured. Evaluation of the
wavelength dependence and the incidence angle
dependence of the mirrors’ reflectance and the filters’transmittance is also important in estimating theradiance expected in CI/HI observations.
We estimated the mirror’s reflectance (or the filter’stransmittance) by calculating the ratio of the radiancewhen a mirror was placed on the main stage (or a filter
was placed on the filter stage) to it when nothing wasplaced on the optical path (Fig. 1). Wavelength scan
was performed from 110 nm to 140 nm in 0.2 nm stepwith summing 5 using G3M4 grating. A photo-diodewas used as a detector. The slit width and the pinhole
diameter were set to 0.5 mm and 1 mm, respectively.
Two types of filters are used: named (f1) and (f2) here,
whose transmission peak are around 122 nm and 120
nm, respectively. We also used two kinds of mirrors:(m1) and (m2), an aluminum mirror and a multilayer
dielectric-coated mirror, respectively. Measurements
were repeated several times. Dark current
measurements were performed each time the positionof the stages or the detector was moved.
As a result, the transmittance of the filters and thereflectance of the mirrors at an incident angle of 5
degree are as shown in Fig. 2.
Both filters had a maximum transmittance just under
10 %. Their spectra are so similar that no significant
performance difference was found in this experiment.
The reflectance of (m2) at an incident angle of 5 deg
was found to be 3 times higher than that of (m1).
However, when the incident angle was 10 deg, thereflectance of (m2) became 250 % at maximum (thefigure is omitted). Although we re- measured in anotherday, the reflectance was still up to 200 %. It is possiblethat stray light has occurred in the experimental system.

The further optimaization (stray light cut or noise
reduction) for the setting are needed.

Fig. 1. The setup of the measurements.

Fig. 2. (a) Transmittance of the filters (b) Reflectanceof the mirrors.

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Ⅲ -5. Life, Earth and Planetary Sciences

BL7B

The Influence of Space Weathering on The Wavelength of The Solar System
Organic Matter PAH
1

J. Yang1, S. Nishimuara1,2, H. Lin1, K. Yoshioka1,2 and I. Yoshikawa1,2

Department of Complexity Science and Engineering, Graduate School of Frontier Sciences, The University of Tokyo,
Kashiwa 277-8561, Japan2
Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo,
Tokyo 113-0033, Japan

Polycyclic aromatic hydrocarbons (PAH or PAHs),
known as polycyclic aromatic compounds or polycyclicaromatic hydrocarbons.
Reflectance spectroscopy can be used to analyze
polycyclic aromatic hydrocarbons, because PAH has avery unique ultraviolet absorption spectrum. Each ring
structure has a unique UV spectrum (Mansouri 2020), so
each isomer has a different UV absorption spectrum. Thisis particularly useful in PAH identification. Most PAHs
are also fluorescent, and when they are excited (whenmolecules absorb light) they emit light of characteristic
wavelengths.
An analysis of the ultraviolet reflectance spectrum ofinterstellar dust has found an absorption band with awavelength of 217.5 nanometers.
In order to understand the "extinction bulge" of the217.5 nm interstellar medium (ISM), the spectral
properties of carbon compounds have been extensively
studied. The strongest feature in the interstellar extinction
curve is the UV "bump" at 217.5 nm (Stecher 1965), also
known as the 220 nm feature. The most obvious point of
this feature is that the center wavelength is very stable,
but the bandwidth varies with the environment of theuniverse. The ultraviolet spectrum of PAH has thischaracteristic.
It is known that those PAHs having a particularly large
molecular weight have absorption band characteristics inthe UV region, and PAH mixtures existing on the earth
have an absorption band around a wavelength of 210 nm.
Due to the weathering of the universe, PAH may increase
the wavelength range of the ultraviolet absorption bandin the universe. Therefore, assuming that the absorption
band corresponds to the 217.5 nm absorption band
appearing in the interstellar darkening curve (the curve
depicting the absorption spectrum of interstellar dust), it
can correspond to the PAH whose reflection bandwavelength is approximately 210 nm on the earth.
This experiment is to observe and analyze theinfluence of space weathering on the optical properties of
PAH. We have prepared PAH samples synthesized in thelaboratory and PAH samples exposed on the International
Space Station (ISS) (exposed samples) and similarly
synthesized and stored in the laboratory (unexposed
samples) for comparison experiments. (Both exposed andunexposed samples are made of PAH only, not a
mixture.) We compared the reflection characteristics ofthese samples with the reflection characteristics of nonexposed samples in the 100-300 nm wavelength range (in1nm step).

The reflection characteristics of the coronene
sample show a significant decline near the wavelengthof 270 nm, and show a trend in the wavelength regionof 210-280 nm, that is, the attenuation of reflected
light is more obvious at longer wavelengths (Fig. 2).
This trend indicates that due to spatial weathering, thewavelength corresponding to the bottom of the dip
may shift to a longer wavelength.

Fig. 1. The main chamber of BL7B.

Fig. 2. The reflection characteristics of coronene
samples in the wavelength range of 160-300 nm.
[1] T. P. Stecher, Astrophys. J. 142 (1965) 1683.
[2] E. Mansouri, V. Yousefi, V. Ebrahimi et al., Sep Sci
plus 3 (2020) 112.

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