1,722 research outputs found
Neutrino Decays and Neutrino Electron Elastic Scattering in Unparticle Physics
Following Georgi's unparticle scheme, we examine the effective couplings
between neutrinos and unparticle operators. As an immediate consequence,
neutrinos become unstable and can decay into the unparticle stuff. Assuming the
dimension transmutation scale is around , we implement the cosmological limit on the neutrino lifetime to
constrain the neutrino-unparticle couplings for different scaling dimensions
. In addition, provided that the electron-unparticle coupling is restricted
due to the precise measurement of the anomalous magnetic moment of electron, we
calculate the unparticle contribution to the neutrino-electron elastic
scattering. It is more important to jointly deal with the couplings of the
unparticle to the standard model particles rather than separately. Taking into
account both electron- and neutrino-unparticle couplings, we find that the
scaling dimension of the scalar unparticle should lie in the narrow range by requiring the observables to be physically meaningful. However, there
is no consistent range of for the vector unparticle operator.Comment: 10 pages including 2 PS figures; v2: an error removed and the text
rewritten; v3: minor changes, accepted for publication in Phys. Lett.
Responsiveness of voltage-gated calcium channels in SH-SY5Y human neuroblastoma cells on quasi-three-dimensional micropatterns formed with poly (l-lactic acid)
Introduction:
In this study, quasi-three-dimensional (3D) microwell patterns were fabricated with poly (l-lactic acid) for the development of cell-based assays, targeting voltage-gated calcium channels (VGCCs).
Methods and materials:
SH-SY5Y human neuroblastoma cells were interfaced with the microwell patterns and found to grow as two dimensional (2D), 3D, and near two dimensional (N2D), categorized on the basis of the cells’ location in the pattern. The capability of the microwell patterns to support 3D cell growth was evaluated in terms of the percentage of the cells in each growth category. Cell spreading was analyzed in terms of projection areas under light microscopy. SH-SY5Y cells’ VGCC responsiveness was evaluated with confocal microscopy and a calcium fluorescent indicator, Calcium GreenTM-1. The expression of L-type calcium channels was evaluated using immunofluorescence staining with DM-BODIPY.
Results:
It was found that cells within the microwells, either N2D or 3D, showed more rounded shapes and less projection areas than 2D cells on flat poly (l-lactic acid) substrates. Also, cells in microwells showed a significantly lower VGCC responsiveness than cells on flat substrates, in terms of both response magnitudes and percentages of responsive cells, upon depolarization with 50 mM K+. This lower VGCC responsiveness could not be explained by the difference in L-type calcium channel expression. For the two patterns addressed in this study, N2D cells consistently exhibited an intermediate value of either projection areas or VGCC responsiveness between those for 2D and 3D cells, suggesting a correlative relation between cell morphology and VGCC responsiveness.
Conclusion:
These results suggest that the pattern structure and therefore the cell growth characteristics were critical factors in determining cell VGCC responsiveness and thus provide an approach for engineering cell functionality in cell-based assay systems and tissue engineering scaffolds
Application of thermosensitive-hydrogel combined with dental pulp stem cells on the injured fallopian tube mucosa in an animal model
Objectives: Fallopian tube (FT) injury is an important factor that can lead to tubal infertility. Stem-cell-based therapy shows great potential for the treatment of injured fallopian tube. However, little research has shown that mesenchymal stem cells (MSCs) can be used to treat fallopian tube damage by in situ injection. In this study, we in situ transplanted PF127 hydrogel encapsulating dental pulp stem cells (DPSCs) into the injured sites to promote the repair and regeneration of fallopian tube injury.Materials and methods: The properties of dental pulp stem cells were evaluated by flow cytometry, immunofluorescence analysis, and multi-differentiation detection. The immunomodulatory and angiogenic characteristics of dental pulp stem cells were analyzed on the basis of the detection of inflammatory factor expression and the formation of capillary-like structures, respectively. The biocompatibility of PF127 hydrogel was evaluated by using Live/Dead and CCK-8 assays. The effects of PF127 hydrogel containing dental pulp stem cells on the repair and regeneration of fallopian tube injury were evaluated by histological analysis [e.g., hematoxylin and eosin (H&E) and Masson’s trichrome staining, TUNEL staining, immunofluorescence staining, and immunohistochemistry], Enzyme-linked immunosorbent assay (ELISA), and RT-PCR detections.Results: Dental pulp stem cells had MSC-like characteristics and great immunomodulatory and angiogenic properties. PF127 hydrogel had a thermosensitive feature and great cytocompatibility with dental pulp stem cells. In addition, our results indicated that PF127 hydrogel containing dental pulp stem cells could promote the repair and regeneration of fallopian tube damage by inhibiting cell apoptosis, stimulating the secretion of angiogenic factors, promoting cell proliferation, modulating the secretion of inflammatory factors, and restoring the secretion of epithelial cells.Conclusion: In this study, our results reported that in situ injection of PF127 hydrogel encapsulating dental pulp stem cells into the injured sites could provide an attractive strategy for the future treatment of fallopian tube injury in clinical settings
Deviation from Tri-Bimaximal Mixing and Large Reactor Mixing Angle
Recent observations for a non-zero have come from various
experiments. We study a model of lepton mixing with a 2-3 flavor symmetry to
accommodate the sizable measurement. In this work, we derive
deviations from the tri-bimaximal (TBM) pattern arising from breaking the
flavor symmetry in the neutrino sector, while the charged leptons contribution
has been discussed in a previous work. Contributions from both sectors towards
accommodating the non-zero measurement are presented.Comment: 25 pages, 12 figures. arXiv admin note: text overlap with
arXiv:1109.232
Triazine containing N-rich microporous organic polymers for CO2 capture and unprecedented CO2/N2 selectivity
Targeted synthesis of microporous adsorbents for CO2 capture and storage is very challenging in the context of remediation from green house gases. Herein we report two novel N-rich microporous networks SB-TRZ-CRZ and SB-TRZ-TPA by extensive incorporation of triazine containing tripodal moiety in the porous polymer framework. These materials showed excellent CO2 storage capacities: SB-TRZ-CRZ displayed the CO2 uptake capacity of 25.5 wt% upto 1 bar at 273 K and SB-TRZ-TPA gave that of 16 wt% under identical conditions. The substantial dipole quadruple interaction between network (polar triazine) and CO2 boosts the selectivity for CO2/N2. SB-TRZ-CRZ has this CO2/N2 selectivity ratio of 377, whereas for SB-TRZ-TPA it was 97. Compared to other porous polymers, these materials are very cost effective, scalable and very promising material for clean energy application and environmental issues
Tapered microfiber MZI Biosensor for highly sensitive detection of Staphylococcus aureus
A new double-taper microfiber Mach-Zehnder interferometer (MZI) biosensor is applied for Staphylococcus aureus (S. aureus) detection. The microfiber MZI structure is fabricated by creating two tapers along a traditional single mode fiber (SMF) firstly and tapering the SMF sandwiched between two tapers into very small diameter (in the order of micrometers). The measured refractive index (RI) sensitivity of the microfiber MZI is up to 2731.1 nm/RIU in the RI range of 1.34 when the taper waist diameter was 10.2 μm, which is in good agreement with numerical simulation results by using the beam propagation method (BPM). The microfiber MZI functionalized with pig immunoglobulin (pig IgG) could be used to specifically binding to S. aureus. In experiment, the maximum wavelength shift of 1.408 nm was achieved when the microfiber biosensors were immersed into S. aureus with concentration of 7×101 CFU/mL. The limit of detection (LoD) of the microfiber biosensor for S. aureus is calculated as low as 11 CFU/mL. The proposed microfiber MZI biosensor has advantages of simple structure configuration, high sensitivity, good repeatability and specificity, wide detection range and fast detection response time (<30 minutes) and thus was demonstrated a good application prospect in food safety inspection, biochemical sensing, diseases and medical diagnostics
Experimental and theoretical investigation of ligand effects on the synthesis of ZnO nanoparticles
ZnO nanoparticles with highly controllable particle sizes(less than 10 nm) were synthesized using organic capping ligands in Zn(Ac)2 ethanolic solution. The molecular structure of the ligands was found to have significant influence on the particle size. The multi-functional molecule tris(hydroxymethyl)-aminomethane (THMA) favoured smaller particle distributions compared with ligands possessing long hydrocarbon chains that are more frequently employed. The adsorption of capping ligands on ZnnOn crystal nuclei (where n = 4 or 18 molecular clusters of(0001) ZnO surfaces) was modelled by ab initio methods at the density functional theory (DFT) level. For the molecules examined, chemisorption proceeded via the formation of Zn...O, Zn...N, or Zn...S chemical bonds between the ligands and active Zn2+ sites on ZnO surfaces. The DFT results indicated that THMA binds more strongly to the ZnO surface than other ligands, suggesting that this molecule is very effective at stabilizing ZnO nanoparticle surfaces. This study, therefore, provides new insight into the correlation between the molecular structure of capping ligands and the morphology of metal oxide nanostructures formed in their presence
Photovoltaic and Amplified Spontaneous Emission Studies of High-Quality Formamidinium Lead Bromide Perovskite Films
Development and validation of a three-dimensional deep learning-based system for assessing bowel preparation on colonoscopy video
BackgroundThe performance of existing image-based training models in evaluating bowel preparation on colonoscopy videos was relatively low, and only a few models used external data to prove their generalization. Therefore, this study attempted to develop a more precise and stable AI system for assessing bowel preparation of colonoscopy video.MethodsWe proposed a system named ViENDO to assess the bowel preparation quality, including two CNNs. First, Information-Net was used to identify and filter out colonoscopy video frames unsuitable for Boston bowel preparation scale (BBPS) scoring. Second, BBPS-Net was trained and tested with 5,566 suitable short video clips through three-dimensional (3D) convolutional neural network (CNN) technology to detect BBPS-based insufficient bowel preparation. Then, ViENDO was applied to complete withdrawal colonoscopy videos from multiple centers to predict BBPS segment scores in clinical settings. We also conducted a human-machine contest to compare its performance with endoscopists.ResultsIn video clips, BBPS-Net for determining inadequate bowel preparation generated an area under the curve of up to 0.98 and accuracy of 95.2%. When applied to full-length withdrawal colonoscopy videos, ViENDO assessed bowel cleanliness with an accuracy of 93.8% in the internal test set and 91.7% in the external dataset. The human-machine contest demonstrated that the accuracy of ViENDO was slightly superior compared to most endoscopists, though no statistical significance was found.ConclusionThe 3D-CNN-based AI model showed good performance in evaluating full-length bowel preparation on colonoscopy video. It has the potential as a substitute for endoscopists to provide BBPS-based assessments during daily clinical practice
First observations of hadrons
Based on events collected with
the BESIII detector, five hadronic decays are searched for via process
. Three of them, ,
, and are observed for the first
time, with statistical significances of 7.4, , and
9.1, and branching fractions of ,
, and ,
respectively, where the first uncertainties are statistical and the second
systematic. No significant signal is observed for the other two decay modes,
and the corresponding upper limits of the branching fractions are determined to
be and at 90% confidence level.Comment: 17 pages, 16 figure
- …