100 research outputs found

    A Two-Stage Training Framework for Joint Speech Compression and Enhancement

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    This paper considers the joint compression and enhancement problem for speech signal in the presence of noise. Recently, the SoundStream codec, which relies on end-to-end joint training of an encoder-decoder pair and a residual vector quantizer by a combination of adversarial and reconstruction losses,has shown very promising performance, especially in subjective perception quality. In this work, we provide a theoretical result to show that, to simultaneously achieve low distortion and high perception in the presence of noise, there exist an optimal two-stage optimization procedure for the joint compression and enhancement problem. This procedure firstly optimizes an encoder-decoder pair using only distortion loss and then fixes the encoder to optimize a perceptual decoder using perception loss. Based on this result, we construct a two-stage training framework for joint compression and enhancement of noisy speech signal. Unlike existing training methods which are heuristic, the proposed two-stage training method has a theoretical foundation. Finally, experimental results for various noise and bit-rate conditions are provided. The results demonstrate that a codec trained by the proposed framework can outperform SoundStream and other representative codecs in terms of both objective and subjective evaluation metrics. Code is available at \textit{https://github.com/jscscloris/SEStream}

    Primary breast osteosarcoma in a patient previously treated for ipsilateral invasive ductal carcinoma: An unusual case report with clinical and genomic features

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    Primary breast osteosarcoma is a rare subtype of breast malignancy with limited clinical evidence, inadequate biological understanding, and unmet treatment consensus. Here, we report an unusual case of primary breast osteosarcoma developing in the same quadrant of the breast 2 years after initial dissection and radiation of invasive ductal carcinoma. Thorough evaluations of imaging and pathology were conducted while genomic alterations of both primary and secondary tumors, as well as peripheral blood samples, were explored through the next-generation sequencing technique. A comprehensive review of the current literature was also performed on this rare malignancy

    The changes of the interspace angle after anterior correction and instrumentation in adolescent idiopathic scoliosis patients

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    <p>Abstract</p> <p>Background</p> <p>In idiopathic scoliosis patients, after anterior spinal fusion and instrumentation, the discs (interspace angle) between the lowest instrumented vertebra (LIV) and the next caudal vertebra became more wedged. We reviewed these patients and analyzed the changes of the angle.</p> <p>Methods</p> <p>By reviewing the medical records and roentgenograms of adolescent idiopathic scoliosis patients underwent anterior spinal fusion and instrumentation, Cobb angle of the curve, correction rate, coronal balance, LIV rotation, interspace angle were measured and analyzed.</p> <p>Results</p> <p>There were total 30 patients included. The mean coronal Cobb angle of the main curve (thoracolumbar/lumbar curve) before and after surgery were 48.9° and 11.7°, respectively, with an average correction rate of 76.1%. The average rotation of LIV before surgery was 2.1 degree, and was improved to 1.2 degree after surgery. The interspace angle before surgery, on convex side-bending films, after surgery, at final follow up were 3.2°, -2.3°, 1.8° and 4.9°, respectively. The difference between the interspace angle after surgery and that preoperatively was not significant (P = 0.261), while the interspace angle at final follow-up became larger than that after surgery, and the difference was significant(P = 0.012). The interspace angle after surgery was correlated with that on convex side-bending films (r = 0.418, P = 0.022), and the interspace angle at final follow-up was correlated with that after surgery (r = 0.625, P = 0.000). There was significant correlation between the loss of the interspace angle and the loss of coronal Cobb angle of the main curve during follow-up(r = 0.483, P = 0.007).</p> <p>Conclusion</p> <p>The interspace angle could be improved after anterior correction and instrumentation surgery, but it became larger during follow-up. The loss of the interspace angle was correlated with the loss of coronal Cobb angle of the main curve during follow-up.</p

    Effects of biochar application and nutrient fluctuation on the growth, and cadmium and nutrient uptake of Trifolium repens with different planting densities in Cd-contaminated soils

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    Biochar has been used to remediate contaminated-soil with heavy metals, however, less is known on how biochar interacts with planting density and nutrient fluctuation to affect the remediation. A pot experiment was conducted in the greenhouse to investigate the effects of biochar application (without vs. with 1% biochar, g/g substrate), nutrient fluctuation (constant vs. pulsed) and planting density (1-, 3- and 6-individuals per pot) on the growth, and cadmium (Cd) and nutrient uptake of Trifolium repens population. Our results found that the growth of T. repens population increased significantly with increasing planting density, and the increment decreased with increasing planting density. Both the Cd and nutrient uptake were higher at higher planting density (e.g., 3- and 6-individuals) than at lower planting density (e.g., 1-individual). Biochar application increased the biomass and shoot Cd uptake, but decreased the ratio of root to shoot and root Cd uptake of T. repens population, the effects of which were significantly influenced by planting density. Although nutrient fluctuation had no effect on the growth of T. repens population, but its interaction with planting density had significant effects on Cd uptake in tissues. Overall, the effects of biochar application and nutrient fluctuation on the growth and Cd uptake were both influenced by planting density in the present study. Our findings highlight that biochar application and constant nutrient supply at an appropriate planting density, such as planting density of 3-individuals per pot in the present study, could promote the growth, and Cd and nutrient uptake of T. repens population

    Advances of hafnium based nanomaterials for cancer theranostics

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    Hafnium-based nanomaterials (Hf-NMs) have attracted the interest of numerous biomedical researchers by their unique properties. Recent years have witnessed significant advancements in the field of Hafnium-based nanomaterials, particularly in the context of cancer diagnosis and treatment. However, research in this area, especially concerning the clinical application of Hafnium-based nanomaterials, has not been thoroughly reviewed. This review will cover: 1) Classification and synthesis of Hafnium-based nanomaterials including Hafnium oxide nanomaterials, Hafnium Metal-Organic Frameworks/nanoscale coordination polymers (MOFs/NCPs); 2) Hafnium-based nanomaterials act as contrast enhancement agent for cancer imaging, and hafnium-based nanomaterials used for diagnosis in cancer liquid biopsy; 3) hafnium-based nanomaterials for cancer therapy, including hafnium-based nanomaterials for radiotherapy, hafnium-based nanomaterials for photodynamic therapy, hafnium-based nanomaterials for various combined therapy; and 4) Translation, toxicity, and safety for Hf-NMs in human and preclinical animal models. More attention will be given to the clinical translation of Hf-NMs in cancer

    Loss of circSRY reduces γH2AX level in germ cells and impairs mouse spermatogenesis.

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    Sry on the Y chromosome is the master switch of sex determination in mammals. It has been well established that Sry encodes a transcription factor that is transiently expressed in somatic cells of the male gonad, leading to the formation of testes. In the testis of adult mice, Sry is expressed as a circular RNA (circRNA) transcript. However, the physiological function of Sry circRNA (circSRY) remains unknown since its discovery in 1993. Here we show that circSRY is mainly expressed in the spermatocytes, but not in mature sperm or somatic cells of the testis. Loss of circSRY led to germ cell apoptosis and the reduction of sperm count in the epididymis. The level of γH2AX was decreased, and failure of XY body formation was noted in circSRY KO germ cells. Further study demonstrated that circSRY directly bound to miR-138-5p in spermatocytes, and in vitro assay suggested that circSRY regulates H2AX mRNA through sponging miR-138-5p. Our study demonstrates that, besides determining sex, Sry also plays an important role in spermatogenesis as a circRNA

    Nonepitaxial Gold-Tipped ZnSe Hybrid Nanorods for Efficient Photocatalytic Hydrogen Production

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    For the first time, colloidal gold (Au)–ZnSe hybrid nanorods (NRs) with controlled size and location of Au domains are synthesized and used for hydrogen production by photocatalytic water splitting. Au tips are found to grow on the apices of ZnSe NRs nonepitaxially to form an interface with no preference of orientation between Au(111) and ZnSe(001). Density functional theory calculations reveal that the Au tips on ZnSe hybrid NRs gain enhanced adsorption of H compared to pristine Au, which favors the hydrogen evolution reaction. Photocatalytic tests reveal that the Au tips on ZnSe NRs effectively enhance the photocatalytic performance in hydrogen generation, in which the single Au-tipped ZnSe hybrid NRs show the highest photocatalytic hydrogen production rate of 437.8 µmol h−1 g−1 in comparison with a rate of 51.5 µmol h−1 g−1 for pristine ZnSe NRs. An apparent quantum efficiency of 1.3% for hydrogen evolution reaction for single Au-tipped ZnSe hybrid NRs is obtained, showing the potential application of this type of cadmium (Cd)-free metal–semiconductor hybrid nanoparticles (NPs) in solar hydrogen production. This work opens an avenue toward Cd-free hybrid NP-based photocatalysis for clean fuel production.W.C. and X.L. contributed equally to this work. This work was supported by the Australian Research Council (ARC) Discovery Early Career Researcher Award (DECRA) (DE 160100589) and discovery project (DP 170104264). Y.L. acknowledges support from the NSFC (grant no. 11674131). W.C. acknowledges the scholarship from the China Scholarship Council

    Stability and genetic insights of the co-existence of blaCTX-M-65, blaOXA-1, and mcr-1.1 harboring conjugative IncI2 plasmid isolated from a clinical extensively-drug resistant Escherichia coli ST744 in Shanghai

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    BackgroundCo-existence of colistin, β-lactam and carbapenem in multidrug-resistant Enterobacteriaceae isolates poses a serious threat to public health. In this study, we investigated and characterized the co-occurrence of blaCTX-M-65, blaOXA-1, and mcr-1.1 strain isolated from a clinical extensively-drug-resistant Escherichia coli ST744 in Shanghai.MethodsAntimicrobial susceptibility test was carried out by agar dilution methods. Whole genome sequencing was conducted, and resistance genes, and sequence types of colistin in E. coli isolates were analyzed. Plasmid stability and amino acid mutations were assessed in E. coli isolates.ResultsA colistin resistant E. coli ST744, named ECPX221, was identified out of 145 fecal samples collected. The strain carries a 60,168 IncI2 plasmid with the mcr-1.1 gene. The strain also has blaCTX-M-65, blaOXA-1, dfrA14, qnrS1, cmlA5, arr2, ampC, aph(4)-Ia, sul1, and aadA5 resistance genes. The plasmid pECPX221 was capable of conjugation with an efficiency of 2.6 × 10−2. Notably, 45% of the transconjugants were determined as mcr-1.1-harboring in the colistin-free environment after 60 generation of passage. No mutations occurred in pmrB, mgrB, and phoPQ gene in the mcr-1.1-harboring transconjugants. Bioinformatic analysis indicated pECPX221 shared highly similar backbone with the previously reported mcr-1.1-harboring pAH62-1, pMFDS1339.1, pSCZE4, and p2018-10-2CC. Furthermore, sequencing and phylogenetic analyses revealed a similarity between other MCR-1-homolog proteins, indicating that ECPX221 was colistin resistant.ConclusionThe stable transferable mcr-1.1-harboring plasmid found in the E. coli ST744 strain indicated the high risk to disseminate the extensively-drug-resistance phenotype among Enterobacteriaceae

    Rod genesis driven by mafba in an nrl knockout zebrafish model with altered photoreceptor composition and progressive retinal degeneration

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    Neural retina leucine zipper (NRL) is an essential gene for the fate determination and differentiation of the precursor cells into rod photoreceptors in mammals. Mutations in NRL are associated with the autosomal recessive enhanced S-cone syndrome and autosomal dominant retinitis pigmentosa. However, the exact role of Nrl in regulating the development and maintenance of photoreceptors in the zebrafish (Danio rerio), a popular animal model used for retinal degeneration and regeneration studies, has not been fully determined. In this study, we generated an nrl knockout zebrafish model via the CRISPR-Cas9 technology and observed a surprising phenotype characterized by a reduced number, but not the total loss, of rods and over-growth of green cones. We discovered two waves of rod genesis, nrl-dependent and -independent at the embryonic and post-embryonic stages, respectively, in zebrafish by monitoring the rod development. Through bulk and single-cell RNA sequencing, we characterized the gene expression profiles of the whole retina and each retinal cell type from the wild type and nrl knockout zebrafish. The over-growth of green cones and mis-expression of green-cone-specific genes in rods in nrl mutants suggested that there are rod/green-cone bipotent precursors, whose fate choice between rod versus green-cone is controlled by nrl. Besides, we identified the mafba gene as a novel regulator of the nrl-independent rod development, based on the cell-type-specific expression patterns and the retinal phenotype of nrl/mafba double-knockout zebrafish. Gene collinearity analysis revealed the evolutionary origin of mafba and suggested that the function of mafba in rod development is specific to modern fishes. Furthermore, the altered photoreceptor composition and abnormal gene expression in nrl mutants caused progressive retinal degeneration and subsequent regeneration. Accordingly, this study revealed a novel function of the mafba gene in rod development and established a working model for the developmental and regulatory mechanisms regarding the rod and green-cone photoreceptors in zebrafish
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