206 research outputs found
Passive Localization of 3D Near-Field Cyclostationary Sources Using Parallel Factor Analysis
By exploiting favorable characteristics of a uniform cross-array, a passive localization algorithm of narrowband cyclostationary sources in the spherical coordinates (azimuth, elevation, and range) is proposed. Firstly, we construct a parallel factor (PARAFAC) analysis model by computing the third-order cyclic moment matrices of the properly chosen sensor outputs. Then, we analyze the uniqueness of the constructed model and obtain three-dimensional (3D) near-field parameters via trilinear alternating least squares regression (TALS). The investigated algorithm is well suitable for the localization of the near-field cyclostationary sources. In addition, it avoids the multidimensional search and pairing parameters. Results of computer simulations are carried out to confirm the satisfactory performance of the proposed method
Expression of peroxiredoxins in the human testis, epididymis and spermatozoa and their role in preventing H2O2-induced damage to spermatozoa
Introduction. High levels of reactive oxygen species (ROS) have potential toxic effects on testicular function and sperm quality. Peroxiredoxins (PRDXs) are enzymes with a role as ROS scavenger. The aim of the study was to reveal the presence and localization of PRDXs in human testis, epididymis and spermatozoa, and the protective roles of PRDX2 and PRDX6 in sperm motility. Material and methods. The presence and localization of PRDXs in the human testis, epididymis and spermatozoa were detected by immunohistochemistry, western blot and immunofluorescence. The effect of anti-peroxidative damage to spermatozoa was examined by adding H2O2 to the recombinant protein-treated spermatozoa. Results. There were strong signals of PRDX1 in spermatogonia and round spermatids; PRDX2 in the round spermatids; PRDX4 and 5 in spermatogonia; PRDX6 in Sertoli cells. PRDXs were also found in epididymal epithelial cells where the expression of PRDX1, 4, 5, 6 in the cauda was higher than in the caput of epididymis. PRDX1-6 immunoreactivity was found throughout acrosome, post-acrosomal region, equatorial segment, neck and cytoplasmic droplet, midpiece and principal piece. The H2O2-induced reduction in sperm motility was reversed by recombinant PRDX2 or PRDX6 in a dose-dependent manner.
Conclusions. PRDX1-6 in the human testis and epididymis presented cell-specificity. PRDX2 and 6 are potential antioxidant protectors for human spermatozoa
Joint 2D Direction-of-Arrival and Range Estimation for Nonstationary Sources
Passive localization of nonstationary sources in the spherical coordinates (azimuth, elevation, and range) is considered, and a parallel factor analysis based method is addressed for the near-field parameter estimation problem. In this scheme, a parallel factor analysis model is firstly constructed by computing five time-frequency distribution matrices of the properly chosen observation data. In addition, the uniqueness of the constructed model is proved, and both the two-dimensional (2D) direction-of-arrival (DOA) and range can be jointly obtained via trilinear alternating least squares regression (TALS). The investigated algorithm is well suitable for near-field nonstationary source localization and does not require parameter-pairing or multidimensional search. Several simulation examples confirm the effectiveness of the proposed algorithm
Exposure to Sevoflurane Affects the Development of Parvalbumin Interneurons in the Main Olfactory Bulb in Mice
Editorial: Omics-originated exploration of pathogenic patterns and molecular mechanisms in human and animal fungal pathogens
Captivity causes taxonomic and functional convergence of gut microbial communities in bats
Background Diet plays a crucial role in sculpting microbial communities. Similar diets appear to drive convergence of gut microbial communities between host species. Captivity usually provides an identical diet and environment to different animal species that normally have similar diets. Whether different species’ microbial gut communities can be homogenized by a uniform diet in captivity remains unclear. Methods In this study, we compared gut microbial communities of three insectivorous bat species (Rhinolophus ferrumequinum, Vespertilio sinensis, and Hipposideros armiger) in captivity and in the wild using 16S rDNA sequencing. In captivity, R. ferrumequinum and V. sinensis were fed yellow mealworms, while H. armiger was fed giant mealworms to rule out the impact of an identical environment on the species’ gut microbial communities. Results We found that the microbial communities of the bat species we studied clustered by species in the wild, while the microbial communities of R. ferrumequinum and V. sinensis in captivity clustered together. All microbial functions found in captive V. sinensis were shared by R. ferrumequinum. Moreover, the relative abundances of all metabolism related KEGG pathways did not significantly differ between captive R. ferrumequinum and V. sinensis; however, the relative abundance of “Glycan Biosynthesis and Metabolism” differed significantly between wild R. ferrumequinum and V. sinensis. Conclusion Our results suggest that consuming identical diets while in captivity tends to homogenize the gut microbial communities among bat species. This study further highlights the importance of diet in shaping animal gut microbiotas
Pharmaco-transcriptomic correlation analysis reveals novel responsive signatures to HDAC inhibitors and identifies Dasatinib as a synergistic interactor in small-cell lung cancer.
BACKGROUND
Histone acetylation/deacetylase process is one of the most studied epigenetic modifications. Histone deacetylase inhibitors (HDACis) have shown clinical benefits in haematological malignancies but failed in solid tumours due to the lack of biomarker-driven stratification.
METHODS
We perform integrative pharmaco-transcriptomic analysis by correlating drug response profiles of five pan-HDACis with transcriptomes of solid cancer cell lines (n=659) to systematically identify generalizable gene signatures associated with HDACis sensitivity and resistance. The established signatures are then applied to identify cancer subtypes that are potentially sensitive or resistant to HDACis, and drugs that enhance the efficacy of HDACis. Finally, the reproductivity of the established HDACis signatures is evaluated by multiple independent drug response datasets and experimental assays.
FINDINGS
We successfully delineate generalizable gene signatures predicting sensitivity (containing 46 genes) and resistance (containing 53 genes) to all five HDACis, with their reproductivity confirmed by multiple external sources and independent internal assays. Using the gene signatures, we identify low-grade glioma harbouring isocitrate dehydrogenase 1/2 (IDH1/2) mutation and non-YAP1-driven subsets of small-cell lung cancer (SCLC) that particularly benefit from HDACis monotherapy. Further, based on the resistance gene signature, we identify clinically-approved Dasatinib as a synthetic lethal drug with HDACi, synergizing in inducing apoptosis and reactive oxygen species on a panel of SCLC. Finally, Dasatinib significantly enhances the therapeutic efficacy of Vorinostat in SCLC xenografts.
INTERPRETATION
Our work establishes robust gene signatures predicting HDACis sensitivity/resistance in solid cancer and uncovers combined Dasatinib/HDACi as a synthetic lethal combination therapy for SCLC
Evaluation of Retinal Nerve Fiber Layer and Ganglion Cell Complex in Patients with Optic Neuritis or Neuromyelitis Optica Spectrum Disorders Using Optical Coherence Tomography in a Chinese Cohort
We evaluate a cohort of optic neuritis and neuromyelitis optica (NMO) spectrum disorders patients in a territory hospital in China. The peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell complex (GCC) were measured using spectral-domain OCT after 6 months of acute onset. The results showed that both the peripapillary RNFL and macular GCC were significantly thinner in all optic neuritis subtypes compared to controls. In addition, the recurrent optic neuritis and NMO groups showed more severe damage on the RNFL and GCC pattern
Spectroscopic Evidence for Interfacial Charge Separation and Recombination in Graphene-MoS2 Vertical Heterostructures
Vertical van der Waals (vdW) heterostructures consisting of graphene (Gr) and
transition metal dichalcogenides (TMDs) have created a fascinating platform for
exploring optical and electronic properties in the two-dimensional limit.
Previous study has revealed the ultrafast formation of interfacial excitons and
the exciton dynamics in the Gr/MoS2 heterostructure. However, a fully
understanding of interfacial charge separation and the subsequent dynamics in
graphene-based heterostructures remains elusive. Here, we investigate the
carrier dynamics of Gr-MoS2 (including Gr/MoS2 and MoS2/Gr stacking sequences)
heterostructures under different photoexcitation energies and stacking
sequences by comprehensive ultrafast means, including time-resolved terahertz
spectroscopy (TRTS), terahertz emission spectroscopy (TES) and transient
absorption spectroscopy (TAS). We demonstrate that the Gr/MoS2 heterostructure
generates hot electron injection from graphene into the MoS2 layer with
photoexcitation of sub-A-exciton of MoS2, while the interfacial charge
separation in the MoS2/Gr could be partially blocked by the electric field of
substrate. Charge transfer (CT) occurs in same directions for the Gr-MoS2
heterostructures with opposite stacking order, resulting in the opposite
orientations of the interfacial photocurrent, as directly demonstrated by the
terahertz (THz) emission. Moreover, we demonstrate that the recombination time
of interfacial charges after CT is on a timescale of 18 ps to 1 ns, depending
on the density of defect states in MoS2 layer. This work provides a
comprehensive and unambiguous picture of the interfacial charge dynamics of
graphene-based heterostructures, which is essential for developing Gr/TMDs
based optoelectronic devices.Comment: 23 pages, 5 Figure
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