14 research outputs found
High-performance cVEP-BCI under minimal calibration
The ultimate goal of brain-computer interfaces (BCIs) based on visual
modulation paradigms is to achieve high-speed performance without the burden of
extensive calibration. Code-modulated visual evoked potential-based BCIs
(cVEP-BCIs) modulated by broadband white noise (WN) offer various advantages,
including increased communication speed, expanded encoding target capabilities,
and enhanced coding flexibility. However, the complexity of the
spatial-temporal patterns under broadband stimuli necessitates extensive
calibration for effective target identification in cVEP-BCIs. Consequently, the
information transfer rate (ITR) of cVEP-BCI under limited calibration usually
stays around 100 bits per minute (bpm), significantly lagging behind
state-of-the-art steady-state visual evoked potential-based BCIs (SSVEP-BCIs),
which achieve rates above 200 bpm. To enhance the performance of cVEP-BCIs with
minimal calibration, we devised an efficient calibration stage involving a
brief single-target flickering, lasting less than a minute, to extract
generalizable spatial-temporal patterns. Leveraging the calibration data, we
developed two complementary methods to construct cVEP temporal patterns: the
linear modeling method based on the stimulus sequence and the transfer learning
techniques using cross-subject data. As a result, we achieved the highest ITR
of 250 bpm under a minute of calibration, which has been shown to be comparable
to the state-of-the-art SSVEP paradigms. In summary, our work significantly
improved the cVEP performance under few-shot learning, which is expected to
expand the practicality and usability of cVEP-BCIs.Comment: 35 pages, 5 figure
Strong nonlinear optical response and transient symmetry switching in Type-II Weyl semimetal -WP2
The topological Weyl semimetals with peculiar band structure exhibit novel
nonlinear optical enhancement phenomena even for light at optical wavelengths.
While many intriguing nonlinear optical effects were constantly uncovered in
type-I semimetals, few experimental works focused on basic nonlinear optical
properties in type-II Weyl semimetals. Here we perform a fundamental static and
time-resolved second harmonic generation (SHG) on the three dimensional Type-II
Weyl semimetal candidate -WP. Although -WP exhibits
extremely high conductivity and an extraordinarily large mean free path, the
second harmonic generation is unscreened by conduction electrons, we observed
rather strong SHG response compared to non-topological polar metals and
archetypal ferroelectric insulators. Additionally, our time-resolved SHG
experiment traces ultrafast symmetry switching and reveals that polar metal
-WP tends to form inversion symmetric metastable state after
photo-excitation. Intense femtosecond laser pulse could optically drive
symmetry switching and tune nonlinear optical response on ultrafast timescales
although the interlayer coupling of -WP is very strong. Our work is
illuminating for the polar metal nonlinear optics and potential ultrafast
topological optoelectronic applications.Comment: 8 pages, 5 figure
Expression of CIAPIN1 in human colorectal cancer and its correlation with prognosis
<p>Abstract</p> <p>Background</p> <p>The cytokine-induced anti-apoptotic molecule (CIAPIN1) had been found to be a differentially-expressed gene involved in a variety of cancers, and it was also considered as a candidate tumour suppressor gene in gastric cancer, renal cancer and liver cancer. However, studies on the role of CIAPIN1 in colorectal cancer were still unavailable. The aim of this study was to determine the prognostic impact of CIAPIN1 in 273 colorectal cancer (CRC) samples and to investigate the CIAPIN1 expression in CRC cell lines after inducing differentiation.</p> <p>Methods</p> <p>Immunohistochemical analysis was performed to detect the expression of CIAPIN1 in CRC samples from 273 patients. The relationship between CIAPIN1 expression and patients' characteristics (gender, age, location of cancer, UICC stage, local recurrence and tumour grade factors) was evaluated. In addition, these patients were followed up for five consecutive years to investigate the relationship between CIAPIN1 expression and the prognosis of CRC. We induced the differentiation of the CRC cell lines HT29 and SW480, in order to detect the expression of CIAPIN1 in the process of CRC cells differentiation.</p> <p>Results</p> <p>Results indicated that CIAPIN1 was mainly expressed in the cytoplasm and nucleus, and that its expression level in cancer samples was significantly lower than in normal tissues. The Wilcoxon-Mann-Whitney test showed a significant difference in the differential expression of CIAPIN1 in patients with different T and UICC stages, and tumour grade (<it>P </it>= 0.0393, 0.0297 and 0.0397, respectively). The Kaplan-Meier survival analysis demonstrated that the survival time of CRC patients with high expression of CIAPIN1 was longer than those with low expression during the 5-year follow up period (<it>P </it>= 0.0002). COX regression analysis indicated that low expression of CIAPIN1, cancer stage of > pT1, distant organ metastasis (pM<sub>1</sub>), regional lymph node metastasis (> pN<sub>1</sub>) and local recurrence (yes) were independent, poor prognostic factors of CRC (<it>P </it>= 0.012, <it>P </it>= 0.032, <it>P <</it>0.001, <it>P <</it>0.001, <it>P <</it>0.001 respectively). Both Western blotting and RT-PCR showed that CIAPIN1 expression was increased with the degree of differentiation of HT29 and SW480 cells.</p> <p>Conclusions</p> <p>CIAPIN1 played an important role in the differentiation of CRC cells, and the differential expression of CIAPIN1 in CRC was closely related to prognosis.</p
Phonon promoted charge density wave in topological kagome metal ScVSn
Charge density wave (CDW) orders in vanadium-based kagome metals have
recently received tremendous attention due to their unique properties and
intricate interplay with exotic correlated phenomena, topological and
symmetry-breaking states. However, the origin of the CDW order remains a topic
of debate. The discovery of ScVSn, a vanadium-based bilayer kagome
metal exhibiting an in-plane x 30
CDW order with time-reversal symmetry breaking, provides a novel platform to
explore the underlying mechanism behind the unconventional CDW. Here, we
combine high-resolution angle-resolved photoemission spectroscopy, Raman
scattering measurements and density functional theory to investigate the
electronic structures and phonon modes of ScVSn and their evolution
with temperature. We identify topologically nontrivial Dirac surface states and
multiple van Hove singularities (VHSs) in the vicinity of the Fermi level, with
one VHS near the K point exhibiting nesting wave vectors in proximity to the
x 30 CDW wave vector. Additionally,
Raman measurements indicate a strong intrinsic electron-phonon coupling in
ScVSn, as evidenced by the presence of a two-phonon mode and a
large frequency amplitude mode. Our findings highlight the fundamental role of
lattice degrees of freedom in promoting the CDW in ScVSn and
provide important insights into the fascinating correlation phenomena observed
in kagome metals
Estimating and approaching the maximum information rate of noninvasive visual brain-computer interface
An essential priority of visual brain-computer interfaces (BCIs) is to enhance the information transfer rate (ITR) to achieve high-speed communication. Despite notable progress, noninvasive visual BCIs have encountered a plateau in ITRs, leaving it uncertain whether higher ITRs are achievable. In this study, we used information theory to study the characteristics and capacity of the visual-evoked channel, which leads us to investigate whether and how we can decode higher information rates in a visual BCI system. Using information theory, we estimate the upper and lower bounds of the information rate with the white noise (WN) stimulus. Consequently, we found out that the information rate is determined by the signal-to-noise ratio (SNR) in the frequency domain, which reflects the spectrum resources of the channel. Based on this discovery, we propose a broadband WN BCI by implementing stimuli on a broader frequency band than the steady-state visual evoked potentials (SSVEPs)-based BCI. Through validation, the broadband BCI outperforms the SSVEP BCI by an impressive 7 bps, setting a record of 50 bps. The integration of information theory and the decoding analysis presented in this study offers valuable insights applicable to general sensory-evoked BCIs, providing a potential direction of next-generation human-machine interaction systems
Immunization with a Combination of Three Pneumococcal Proteins Confers Additive and Broad Protection against Streptococcus pneumoniae Infections in Mice▿
Pneumococcal polysaccharide-based vaccines are effective in preventing pneumococcus infection; however, some drawbacks preclude their widespread use in developing and undeveloped countries. Here, we evaluated the protective effects of ATP-dependent caseinolytic protease (ClpP), pneumolysin mutant (ΔA146 Ply), putative lipoate-protein ligase (Lpl), or combinations thereof against pneumococcal infections in mice. Vaccinated mice were intraperitoneally and/or intranasally challenged with different pneumococcal strains. In intraperitoneal challenge models with pneumococcal strain D39 (serotype 2), the most striking protection was obtained with the combination of the three antigens. Similarly, with the intranasal challenge models, (i) additive clearance of bacteria in lungs was observed for the combination of the three antigens and (ii) a combination vaccine conferred complete protection against intranasal infections of three of the four most common pneumococcal strains (serotypes 14, 19F, and 23F) and 80% protection for pneumococcal strain 6B. Even so, immunity to this combination could confer protection against pneumococcal infection with a mixture of four serotypes. Our results showed that the combination vaccine was as effective as the currently used vaccines (PCV7 and PPV23). These results indicate that system immunization with the combination of pneumococcal antigens could provide an additive and broad protection against Streptococcus pneumoniae in pneumonia and sepsis infection models
High-Pressure Synthesis of 5d Cubic Perovskite BaOsO<sub>3</sub> at 17 GPa: Ferromagnetic Evolution over 3d to 5d Series
In continuation of the series of
perovskite oxides that includes
3d<sup>4</sup> cubic BaFeO<sub>3</sub> and 4d<sup>4</sup> cubic BaRuO<sub>3</sub>, 5d<sup>4</sup> cubic BaOsO<sub>3</sub> was synthesized by
a solid-state reaction at a pressure of 17 GPa, and its crystal structure
was investigated by synchrotron powder X-ray diffraction measurements.
In addition, its magnetic susceptibility, electrical resistivity,
and specific heat were measured over temperatures ranging from 2 to
400 K. The results establish a series of d<sup>4</sup> cubic perovskite
oxides, which can help in the mapping of the itinerant ferromagnetism
that is free from any complication from local lattice distortions
for transitions from the 3d orbital to the 5d orbital. Such a perovskite
series has never been synthesized at any d configuration to date.
Although cubic BaOsO<sub>3</sub> did not exhibit long-range ferromagnetic
order unlike cubic BaFeO<sub>3</sub> and BaRuO<sub>3</sub>, enhanced
feature of paramagnetism was detected with weak temperature dependence.
Orthorhombic CaOsO<sub>3</sub> and SrOsO<sub>3</sub> show similar
magnetic behaviors. CaOsO<sub>3</sub> is not as conducting as SrOsO<sub>3</sub> and BaOsO<sub>3</sub>, presumably due to impact of tilting
of octahedra on the width of the <i>t</i><sub>2g</sub> band.
These results elucidate the evolution of the magnetism of perovskite
oxides not only in the 5d system but also in group 8 of the periodic
table