245 research outputs found
Polarization-based cyclic weak value metrology for angular velocity measurement
Weak value has been proved to amplify the detecting changes of the meters at
the cost of power due to post-selection. Previous power-recycling schemes
enable the failed post-selection photons to be reselected repeatedly, thus
surpassing the upper noise limit and improving the precision of interferometric
systems. Here we introduce three cyclic methods to improve the sensitivity of
polarization-based weak-value-based angular velocity measurement: power-,
signal- and dual-recycling schemes. By inserting one or two partially
transmitting mirrors inside the system, both the power and precision of
detected signals are greatly enhanced, and the dual-recycling scheme has wider
optimal region than that of power- or signal-recycling schemes. Compared to
non-polarization schemes, polarization-based schemes enjoy lower optical loss
and unique cyclic directions. These reduce the crosstalk among different paths
of light and, theoretically, eliminate the walk-off effect, thus towering in
both theoretical performance and application.Comment: 7 pages, 3 figure
Effects of an allelochemical in Phaeodactylum tricornutum filtrate on Heterosigma akashiwo : morphological, physiological and growth effects
© The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Chemosphere 186 (2017): 527-534, doi:10.1016/j.chemosphere.2017.08.024.The effects of an allelochemical extracted from the culture filtrate of diatom Phaeodactylum
tricornutum on the raphidophyte Heterosigma akashiwo were investigated using a series of
morphological, physiological and biochemical characters. Growth experiments showed that H.
akashiwo was significantly inhibited immediately after exposure to the allelochemical, with many cells
rapidly dying and lysing based on microscopic observation. The effects of the allelochemical on the
surviving cells were explored using Scanning Electron Microscopy (SEM) and Flow cytometry (FCM),
the latter by examination of a suite of physiological parameters (membrane integrity, esterase activity,
chlorophyll-a content, membrane potential). The results demonstrate that the membrane of H. akashiwo
was attacked by the allelochemical directly, causing cell membrane breakage and loss of integrity.
Esterase activity was the most sensitive indicator of the impacts of the allelochemical. Membrane potential and chlorophyll-a content both showed significant decreases following exposure of the
Heterosigma cells to high concentrations of the allelochemical for 5 and 6 days. Both were affected,
but the membrane potential response was more gradual compared to other effects. The cell size of H.
akashiwo did not change compared with the control group. The surviving cells were able to continue to
grow and in a few days, re-establish a successful culture, even in the presence of residual
allelochemical, suggesting either development of cellular resistance, or the degradation of the chemical.The authors wish to thank the National Programme on Global Change and Air-Sea Interaction (Grant
No. GASI-03-01-02-01); the National Key Research and Development Program [Grant No.
2016YFC1402101]; the assessment of nanomaterials on biological and ecological effects in the coastal
area (Grant No. 201505034)
Gynostemma pentaphyllum polysaccharides ameliorate non-alcoholic steatohepatitis in mice associated with gut microbiota and the TLR2/NLRP3 pathway
Recent studies have revealed the pivotal role of gut microbiota in the progress of liver diseases including non-alcoholic steatohepatitis (NASH). Many natural herbs, such as Gynostemma pentaphyllum (GP), have been extensively applied in the prevention of NASH, while the bioactive components and underlying mechanism remain unclear. The aim of this study was to investigate whether the polysaccharides of GP (GPP) have a protective effect on NASH and to explore the potential mechanism underlying these effects. C57BL/6 male mice were fed with a methionine-choline-deficient (MCD) diet for 4 weeks to induce NASH and administered daily oral gavage of sodium carboxymethylcellulose (CMC-Na), low dose of GPP (LGPP), high dose of GPP (HGPP), and polyene phosphatidylcholine capsules (PPC), compared with the methionine-choline-sufficient (MCS) group. Our results showed that the symptoms of hepatic steatosis, hepatocyte ballooning, liver fibrosis, and oxidative stress could be partially recovered through the intervention of GPP with a dose-dependent effect. Furthermore, gut microbiome sequencing revealed that HGPP altered the composition of gut microbiota, mainly characterized by the enrichment of genera including Akkermansia, Lactobacillus, and A2. Moreover, hepatic transcriptome analysis indicated that the anti-inflammatory effect of HGPP might be associated with toll-like receptor (TLR) and nod-like receptor (NLR) signaling pathways. HGPP could inhibit the expression of TLR2 and downregulate the expression of the NLRP3 inflammasome, as well as the pro-inflammatory cytokine tumor necrosis factor (TNF)-α and interleukin (IL)-1β. In summary, GPP could ameliorate NASH possibly mediated via the modulation of gut microbiota and the TLR2/NLRP3 signaling pathway, indicating that GPP could be tested as a prebiotic agent in the prevention of NASH
Inhibited bacterial biofilm formation and improved osteogenic activity on gentamicin-loaded titania nanotubes with various diameters
Plant toxin β-ODAP activates integrin β1 and focal adhesion : a critical pathway to cause neurolathyrism
Neurolathyrism is a unique neurodegeneration disease caused by beta-N-oxalyl-L-alpha, beta-diaminopropionic (beta-ODAP) present in grass pea seed (Lathyrus stativus L.) and its pathogenetic mechanism is unclear. This issue has become a critical restriction to take full advantage of drought-tolerant grass pea as an elite germplasm resource under climate change. We found that, in a human glioma cell line, beta-ODAP treatment decreased mitochondrial membrane potential, leading to outside release and overfall of Ca2+ from mitochondria to cellular matrix. Increased Ca2+ in cellular matrix activated the pathway of ECM, and brought about the overexpression of beta 1 integrin on cytomembrane surface and the phosphorylation of focal adhesion kinase (FAK). The formation of high concentration of FA units on the cell microfilaments further induced overexpression of paxillin, and then inhibited cytoskeleton polymerization. This phenomenon turned to cause serious cell microfilaments distortion and ultimately cytoskeleton collapse. We also conducted qRT-PCR verification on RNA-sequence data using 8 randomly chosen genes of pathway enrichment, and confirmed that the data was statistically reliable. For the first time, we proposed a relatively complete signal pathway to neurolathyrism. This work would help open a new window to cure neurolathyrism, and fully utilize grass pea germplasm resource under climate change
Calibration of the Timing Performance of GECAM-C
As a new member of the Gravitational wave high-energy Electromagnetic
Counterpart All-sky Monitor (GECAM) after GECAM-A and GECAM-B, GECAM-C
(originally called HEBS), which was launched on board the SATech-01 satellite
on July 27, 2022, aims to monitor and localize X-ray and gamma-ray transients
from 6 keV to 6 MeV. GECAM-C utilizes a similar design to GECAM but
operates in a more complex orbital environment. In this work, we utilize the
secondary particles simultaneously produced by the cosmic-ray events on orbit
and recorded by multiple detectors, to calibrate the relative timing accuracy
between all detectors of GECAM-C. We find the result is 0.1 , which
is the highest time resolution among all GRB detectors ever flown and very
helpful in timing analyses such as minimum variable timescale and spectral
lags, as well as in time delay localization. Besides, we calibrate the absolute
time accuracy using the one-year Crab pulsar data observed by GECAM-C and
Fermi/GBM, as well as GECAM-C and GECAM-B. The results are and , respectively. Finally, we investigate the
spectral lag between the different energy bands of Crab pulsar observed by
GECAM and GBM, which is .Comment: submitte
Human Cataract Mutations in EPHA2 SAM Domain Alter Receptor Stability and Function
The cellular and molecular mechanisms underlying the pathogenesis of cataracts leading to visual impairment remain poorly understood. In recent studies, several mutations in the cytoplasmic sterile-α-motif (SAM) domain of human EPHA2 on chromosome 1p36 have been associated with hereditary cataracts in several families. Here, we have investigated how these SAM domain mutations affect EPHA2 activity. We showed that the SAM domain mutations dramatically destabilized the EPHA2 protein in a proteasome-dependent pathway, as evidenced by the increase of EPHA2 receptor levels in the presence of the proteasome inhibitor MG132. In addition, the expression of wild-type EPHA2 promoted the migration of the mouse lens epithelial αTN4-1 cells in the absence of ligand stimulation, whereas the mutants exhibited significantly reduced activity. In contrast, stimulation of EPHA2 with its ligand ephrin-A5 eradicates the enhancement of cell migration accompanied by Akt activation. Taken together, our studies suggest that the SAM domain of the EPHA2 protein plays critical roles in enhancing the stability of EPHA2 by modulating the proteasome-dependent process. Furthermore, activation of Akt switches EPHA2 from promoting to inhibiting cell migration upon ephrin-A5 binding. Our results provide the first report of multiple EPHA2 cataract mutations contributing to the destabilization of the receptor and causing the loss of cell migration activity
Corrigendum to: The TianQin project: current progress on science and technology
In the originally published version, this manuscript included an error related to indicating the corresponding author within the author list. This has now been corrected online to reflect the fact that author Jun Luo is the corresponding author of the article
Management of granulomatous lobular mastitis: an international multidisciplinary consensus (2021 edition)
Granulomatous lobular mastitis (GLM) is a rare and chronic benign inflammatory disease of the breast. Difficulties exist in the management of GLM for many front-line surgeons and medical specialists who care for patients with inflammatory disorders of the breast. This consensus is summarized to establish evidence-based recommendations for the management of GLM. Literature was reviewed using PubMed from January 1, 1971 to July 31, 2020. Sixty-six international experienced multidisciplinary experts from 11 countries or regions were invited to review the evidence. Levels of evidence were determined using the American College of Physicians grading system, and recommendations were discussed until consensus. Experts discussed and concluded 30 recommendations on historical definitions, etiology and predisposing factors, diagnosis criteria, treatment, clinical stages, relapse and recurrence of GLM. GLM was recommended as a widely accepted definition. In addition, this consensus introduced a new clinical stages and management algorithm for GLM to provide individual treatment strategies. In conclusion, diagnosis of GLM depends on a combination of history, clinical manifestations, imaging examinations, laboratory examinations and pathology. The approach to treatment of GLM should be applied according to the different clinical stage of GLM. This evidence-based consensus would be valuable to assist front-line surgeons and medical specialists in the optimal management of GLM.Improving the Ability of Diagnosis and Treatment of Difficult Disease
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