82 research outputs found
Precision Measurement of M1 Optical Clock Transition in Ni12+
Highly charged ions (HCIs) have drawn significant interest in quantum
metrology and in search for new physics. Among these, Ni12+ is considered as
one of the most promising candidates for the next generation of HCI optical
clocks, due to its two E1-forbidden transitions M1 and E2, which occur in the
visible spectral range. In this work, we used the Shanghai-Wuhan Electron Beam
Ion Trap to perform a high-precision measurement of the M1 transition
wavelength. Our approach involved an improved calibration scheme for the
spectra, utilizing auxiliary Ar+ lines for calibration and correction. Our
final measured result of the M1 transition wavelength demonstrates a five-fold
improvement in accuracy compared to our previous findings, reaching the
sub-picometer level accuracy. In combination with our rigorous atomic-structure
calculations to capture the electron correlations and relativistic effects, the
quantum electrodynamic (QED) corrections were extracted. Moreover, comparing
with an estimate of the one-electron QED contributions by using the GRASP2018
package, we found that the present experimental accuracy is high enough for
testing the higher-order QED corrections for such a complex system with four
electrons in the p subshell.Comment: 15 pages, 5 figure
Imaging of brain function based on the analysis of functional connectivity - imaging analysis of brain function by fMRI after acupuncture at LR3 in healthy individuals
Objective: This Study observed the relevant brain areas activated by acupuncture at the Taichong acupoint (LR3) and analyzed the functional connectivity among brain areas using resting state functional magnetic resonance imaging (fMRI) to explore the acupoint specificity of the Taichong acupoint.Methods: A total of 45 healthy subjects were randomly divided into the Taichong (LR3) group, sham acupuncture group and sham acupoint group. Subjects received resting state fMRI before acupuncture, after true (sham) acupuncture in each group. Analysis of changes in connectivity among the brain areas was performed using the brain functional connectivity method.Results: The right cerebrum temporal lobe was selected as the seed point to analyze the functional connectivity. It had a functional connectivity with right cerebrum superior frontal gyrus, limbic lobe cingulate gyrus and left cerebrum inferior temporal gyrus (BA 37), inferior parietal lobule compared by before vs. after acupuncture at LR3, and right cerebrum sub-lobar insula and left cerebrum middle frontal gyrus, medial frontal gyrus compared by true vs. sham acupuncture at LR3, and right cerebrum occipital lobe cuneus, occipital lobe sub-gyral, parietal lobe precuneus and left cerebellum anterior lobe culmen by acupuncture at LR3 vs. sham acupoint.Conclusion: Acupuncture at LR3 mainly specifically activated the brain functional network that participates in visual function, associative function, and emotion cognition, which are similar to the features on LR3 in tradition Chinese medicine. These brain areas constituted a neural network structure with specific functions that had specific reference values for the interpretation of the acupoint specificity of the Taichong acupoint.Keywords: acupuncture, Taichong(LR3), functional magnetic resonance imaging (fMRI), functional connectivit
Immunoregulation of Glia after spinal cord injury: a bibliometric analysis
ObjectiveImmunoregulation is a complex and critical process in the pathological process of spinal cord injury (SCI), which is regulated by various factors and plays an important role in the functional repair of SCI. This study aimed to explore the research hotspots and trends of glial cell immunoregulation after SCI from a bibliometric perspective.MethodsData on publications related to glial cell immunoregulation after SCI, published from 2004 to 2023, were obtained from the Web of Science Core Collection. Countries, institutions, authors, journals, and keywords in the topic were quantitatively analyzed using the R package “bibliometrix”, VOSviewer, Citespace, and the Bibliometrics Online Analysis Platform.ResultsA total of 613 papers were included, with an average annual growth rate of 9.39%. The papers came from 36 countries, with the United States having the highest output, initiating collaborations with 27 countries. Nantong University was the most influential institution. We identified 3,177 authors, of whom Schwartz, m, of the Weizmann Institute of Science, was ranked first regarding both field-specific H-index (18) and average number of citations per document (151.44). Glia ranked first among journals with 2,574 total citations. The keywords “microglia,” “activation,” “macrophages,” “astrocytes,” and “neuroinflammation” represented recent hot topics and are expected to remain a focus of future research.ConclusionThese findings strongly suggest that the immunomodulatory effects of microglia, astrocytes, and glial cell interactions may be critical in promoting nerve regeneration and repair after SCI. Research on the immunoregulation of glial cells after SCI is emerging, and there should be greater cooperation and communication between countries and institutions to promote the development of this field and benefit more SCI patients
Absolute frequency measurements with a robust, transportable ^{40}Ca^{+} optical clock
We constructed a transportable 40Ca+ optical clock (with an estimated minimum
systematic shift uncertainty of 1.3*10^(-17) and a stability of
5*10^(-15)/sqrt{tau} ) that can operate outside the laboratory. We transported
it from the Innovation Academy for Precision Measurement Science and
Technology, Chinese Academy of Sciences, Wuhan to the National Institute of
Metrology, Beijing. The absolute frequency of the 729 nm clock transition was
measured for up to 35 days by tracing its frequency to the second of
International System of Units. Some improvements were implemented in the
measurement process, such as the increased effective up-time of 91.3 % of the
40Ca+ optical clock over a 35-day-period, the reduced statistical uncertainty
of the comparison between the optical clock and hydrogen maser, and the use of
longer measurement times to reduce the uncertainty of the frequency
traceability link. The absolute frequency measurement of the 40Ca+ optical
clock yielded a value of 411042129776400.26 (13) Hz with an uncertainty of
3.2*10^(-16), which is reduced by a factor of 1.7 compared with our previous
results. As a result of the increase in the operating rate of the optical
clock, the accuracy of 35 days of absolute frequency measurement can be
comparable to the best results of different institutions in the world based on
different optical frequency measurements.Comment: 15 pages, 5 figure
IMAGING OF BRAIN FUNCTION BASED ON THE ANALYSIS OF FUNCTIONAL CONNECTIVITY - IMAGING ANALYSIS OF BRAIN FUNCTION BY FMRI AFTER ACUPUNCTURE
Objective: This Study observed the relevant brain areas activated by acupuncture at the Taichong acupoint (LR3) and analyzed the
functional connectivity among brain areas using resting state functional magnetic resonance imaging (fMRI) to explore the acupoint
specificity of the Taichong acupoint.
Methods: A total of 45 healthy subjects were randomly divided into the Taichong (LR3) group, sham acupuncture group and sham
acupoint group. Subjects received resting state fMRI before acupuncture, after true (sham) acupuncture in each group. Analysis of
changes in connectivity among the brain areas was performed using the brain functional connectivity method.
Results: The right cerebrum temporal lobe was selected as the seed point to analyze the functional connectivity. It had a functional
connectivity with right cerebrum superior frontal gyrus, limbic lobe cingulate gyrus and left cerebrum inferior temporal gyrus (BA
37), inferior parietal lobule compared by before vs. after acupuncture at LR3, and right cerebrum sub-lobar insula and left cerebrum
middle frontal gyrus, medial frontal gyrus compared by true vs. sham acupuncture at LR3, and right cerebrum occipital lobe cuneus,
occipital lobe sub-gyral, parietal lobe precuneus and left cerebellum anterior lobe culmen by acupuncture at LR3 vs. sham acupoint.
Conclusion: Acupuncture at LR3 mainly specifically activated the brain functional network that participates in visual function,
associative function, and emotion cognition, which are similar to the features on LR3 in tradition Chinese medicine. These brain
areas constituted a neural network structure with specific functions that had specific reference values for the interpretation of the
acupoint specificity of the Taichong acupoint
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