molecular hydrogen (H 2 ) over
copper–zinc (Cu–Zn) catalysts,
but studies have disagreed
about the chemical state of
Zn. Although x-ray photoelec-
tron spectroscopy (XPS) can
determine its oxidation state,
many studies have been limited
to reaction pressures of a few
millibar, where the rates are low.
Amann et al. performed XPS at
180 to 500 millibar for CO 2 and
CO hydrogenation over a Zn/
ZnO/Cu(211) surface at high
turnover rates. Stoichiometric
mixtures of CO 2 and H 2 formed
ZnO, but for CO and H 2 , Zn
became more metallic and
formed Cu alloys. In industrial
synthesis, CO 2 and H 2 are mixed
with CO, and the presence of
CO would generate Cu–Zn alloy
sites active for CO 2 reduction to
methanol. —PDS
Science, abj7747, this issue p. 603HYDROGELS
Bioinspired frequency
dampening
Physical activity can interfere
with the measurement of
physiological signals and often
requires band-pass filtering to
remove the artifacts. Park et
al. drew inspiration from the
viscoelastic properties of the
cuticular pad of spiders that
can separate target vibration
signals from mechanical noise.
The authors developed a gela-
tin–chitosan hydrogel damper
that will absorb frequencies
below 30 hertz, whereas higherCELL BIOLOGY
The ER controls
microtubule distribution
The endoplasmic reticulum
(ER) and microtubules form an
intricate, mechanically interde-
pendent network within cells.
Although the microtubule cyto-
skeleton influences the shape of
the ER, whether the ER affects
the distribution of microtubules
is less clear. Tikhomirova et al.
combined automated quantita-
tive fluorescence microscopy,
computer vision, and physics-
based modeling and found
that changes in ER shape and
dynamics had a strong impact
on the spatial distribution
of microtubules in the cell.
Perturbations that affected
ER morphology at three-way
ER tubule junctions led to thebundling of microtubules. Thus,
the ER and microtubules should
not be treated as isolated cel-
lular structures because they
appear to be highly interde-
pendent, with the ER having a
central role in controlling the
distribution of microtubules.
—SMH
Proc. Natl. Acad. Sci. U.S.A. 119 ,
e2104309119 (2022).IMMIGRATION
Deporting criminals,
spreading crime
Under the 1996 Illegal
Immigration Responsibility Act,
the United States substantially
increased criminal deportations.
Sviatschi shows that the depor-
tations of members of large
gangs formed in the Unitedfrequencies transmit due to
the temporary disruption of
the weak internetwork bonds
in the hydrogel. The hydrogel
can be used to detect electro-
physiological signals such as
electroencephalograms and
electrocardiograms without
interference caused by the
patient’s walking or breathing.
—MSL
Science, abj9912, this issue p. 624OPTICS
Visualizing motion of
quantized vortexes
A quantized vortex is a mani-
festation of the macroscopic
quantum nature of superfluid
helium and is essential for
understanding its physics.
Minowa et al. generated silicon
nanoparticles in situ in super-
fluid helium by laser ablation and
found that they were attracted to
the cores of quantized vortices.
By illuminating a light sheet to
the silicon nanoparticles, the fila-
ments of the quantum vortices
were visualized. Monitoring the
motion of two quantized vortex
filaments, the authors observed
the reconnection process of
these filaments. The interaction
of light and superfluid helium
through silicon nanoparticles
could be used to investigate and
even manipulate the physical
properties of superfluid helium
using light in future experiments.
—RO
Sci. Adv. 10.1126/
sciadv.abn1143 (2022).GRAPHIC: PARKET AL.592 6 MAY 2022 • VOL 376 ISSUE 6593A hydrogel coating suppresses the elastic collision of a ball on a hard surface at
high temperature (bottom) but less so at cool (middle) or cold (top) conditions.RESEARCH | IN SCIENCE JOURNALSscience.org SCIENCEIN OTHER JOURNALS
Edited by Caroline Ash
and Jesse Smith0506ISIO_15544064.indd 592 5/2/22 5:47 PM