44 research outputs found

    Integrability analysis of a simple model for describing convection of a rotating fluid

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    We study the Darboux integrability of a simple system of three ordinary differential equations called the Glukhovsky-Dolzhansky system, which describes a three-mode model of rotating fluid convection inside the ellipsoid. (1) Our results show that it has no polynomial, rational, or Darboux first integrals for any value of parameters in the physical sense, that is, positive parameters. (2) We also provide some integrable cases of this model when parameters are allowed to be non-positive. (3) We finally give some links between the Glukhovsky-Dolzhansky system and other similar systems in R3\mathbb{R}^3, which admits rotational symmetry and has three nonlinear cross terms

    Primary Anterior Medistinal Choriocarcinoma in Male with Lung Metastasis and Pituitary Microadenoma: A Case Report

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    The authors report a case of a 29-year-old male presented with bilateral breast enlargement with no significant past medical history or estrogen exposure. Serum β-human chorionic gonadotropin (HCG) was 14,306.60 mIU and positron emission tomography-computed tomography discovered a malignant mass on the right side of anterior superior mediastinum. Magnetic resonance imaging demonstrated pituitary microadenoma. Pathological biopsy showed poorly differential pituitary adenoma and immunohistochemical staining displayed that CK(+), PLAP(−), AFP(−), HCG(+), CD30(−), Oct3/4(−), CK7(+), TTF-1(−), CD117(−), Ki 67(80+), CK5/6(−), EMA(partial+), inhibin(partial+). A diagnosis of primary anterior mediastinal choriocarcinoma metastasis to bilateral lungs accompanied with pituitary microadenoma was confirmed. Then the patient received chemotherapy combined with immunotherapy. But serum β-HCG level was still above the normal, and unfortunately, the patient died 6 months after his diagnosis. This case inspires us to think of the possibility of choriocarcinoma when a man presents gynecomastia or lung metastatic symptoms, adding Opdivo to the chemotherapy might not improve the poor treatment outcomes

    Fumarylacetoacetate Hydrolase Knock-out Rabbit Model for Hereditary Tyrosinemia Type 1.

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    Hereditary tyrosinemia type 1 (HT1) is a severe human autosomal recessive disorder caused by the deficiency of fumarylacetoacetate hydroxylase (FAH), an enzyme catalyzing the last step in the tyrosine degradation pathway. Lack of FAH causes accumulation of toxic metabolites (fumarylacetoacetate and succinylacetone) in blood and tissues, ultimately resulting in severe liver and kidney damage with onset that ranges from infancy to adolescence. This tissue damage is lethal but can be controlled by administration of 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione (NTBC), which inhibits tyrosine catabolism upstream of the generation of fumarylacetoacetate and succinylacetone. Notably, in animals lacking FAH, transient withdrawal of NTBC can be used to induce liver damage and a concomitant regenerative response that stimulates the growth of healthy hepatocytes. Among other things, this model has raised tremendous interest for the in vivo expansion of human primary hepatocytes inside these animals and for exploring experimental gene therapy and cell-based therapies. Here, we report the generation of FAH knock-out rabbits via pronuclear stage embryo microinjection of transcription activator-like effector nucleases. FAH-/- rabbits exhibit phenotypic features of HT1 including liver and kidney abnormalities but additionally develop frequent ocular manifestations likely caused by local accumulation of tyrosine upon NTBC administration. We also show that allogeneic transplantation of wild-type rabbit primary hepatocytes into FAH-/- rabbits enables highly efficient liver repopulation and prevents liver insufficiency and death. Because of significant advantages over rodents and their ease of breeding, maintenance, and manipulation compared with larger animals including pigs, FAH-/- rabbits are an attractive alternative for modeling the consequences of HT1.Wellcome Trus

    The Cross-Border Transport of PM2.5 from the Southeast Asian Biomass Burning Emissions and Its Impact on Air Pollution in Yunnan Plateau, Southwest China

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    Southeast Asia is one of the largest biomass burning (BB) regions in the world, and the air pollutants generated by this BB have an important impact on air pollution in southern China. However, the mechanism of the cross-border transport of BB pollutants to neighboring regions is yet to be understood. Based on the MODIS remote sensing products and conventional observation data of meteorology and the environment, the WRF-Chem and FLEXPART-WRF models were used to simulate a typical PM2.5 pollution episode that occurred during 24–26 March 2017 to analyze the mechanism of cross-border transport of BB pollutants over Yunnan Plateau (YP) in southwest China. During this air pollution episode, in conjunction with the flourishing BB activities over the neighboring Indo-China Peninsula (ICP) regions in Southeast Asia, and driven by the southwesterly winds prevailing from the ICP to YP, the cross-border transport of pollutants was observed along the transport pathway with the lifting plateau topography in YP. Based on the proximity to the BB sources in ICP, YP was divided into a source region (SR) and a receptor region (RR) for the cross-border transport, and the negative and positive correlation coefficients (R) between PM2.5 concentrations and wind speeds, respectively, were presented, indicating the different impacts of BB emissions on the two regions. XSBN and Kunming, the representative SR and RR sites in the border and hinterland of YP, respectively, have distinct mechanisms that enhance PM2.5 concentrations of air pollution. The SR site is mainly affected by the ICP BB emissions with local accumulation in the stagnant meteorological conditions, whereas the RR site is dominated by the regional transport of PM2.5 with strong winds and vertical mixing. It was revealed that the large PM2.5 contributions of ICP BB emissions lift from the lower altitudes in SR to the higher altitudes in RR for the regional transport of PM2.5. Moreover, the contributions of regional transport of PM2.5 decrease with the increase in transport distance, reflecting an important role of transport distance between the source–receptor areas in air pollution change

    DARN: Distance Attention Residual Network for Lightweight Remote-Sensing Image Superresolution

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    The application of single-image superresolution (SISR) in remote sensing is of great significance. Although the state-of-the-art convolution neural network (CNN)-based SISR methods have achieved excellent results, the large model and slow speed make it difficult to deploy in real remote sensing tasks. In this article, we propose a compact and efficient distance attention residual network (DARN) to achieve a better compromise between model accuracy and complexity. The distance attention residual connection block (DARCB), the core component of the DARN, uses multistage feature aggregation to learn more accurate feature representations. The main branch of the DARCB adopts a shallow residual block (SRB) to flexibly learn residual information to ensure the robustness of the model. We also propose a distance attention block (DAB) as a bridge between the main branch and the branch of the DARCB; the DAB can effectively alleviate the loss of detail features in the deep CNN extraction process. Experimental results on two remote sensing and five super-resolution benchmark datasets demonstrate that the DARN achieves a better compromise than existing methods in terms of performance and model complexity. In addition, the DARN achieves the optimal solution compared with the state-of-the-art lightweight remote sensing SISR method in terms of parameter amount, computation amount, and inference speed. Our code will be available at https://github.com/candygogogogo/DARN

    Decision-making of portfolio investment with linear plus double exponential utility function

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    This paper broadens the exponential utility function commonly used by risk-averse investors to the linear plus double exponential utility function, which is applicable in most cases. Thus it is of essential and supreme significance to conduct a research on its optimal investment portfolio in securities investment. This paper, by means of the non-difference curve method, carries out a research into the optimal portfolio decision-making by investors who have this type of utility function. The optimal decision-making and the ratio of optimal portfolio investment are derived. Finally, an actual case is given to verify the relevant results

    Remote cerebellar hemorrhage following repeated lumbar punctures

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    Abstract Background Remote cerebellar hemorrhage (RCH) is a rare complication in neurosurgery. No case of RCH secondary to repeated lumbar punctures (LPs) has been previously reported. Case presentation A 49-year-old man presented with impaired consciousness following persistent fever. Cerebrospinal fluid examination showed high opening pressure, elevated white blood cells, increased protein level, and decreased glucose level, resulting in a diagnosis of bacterial meningoencephalitis. Treatment with repeated LPs and intrathecal injection of ceftriaxone resulted in an improvement in neurological symptoms. However, on day 31 of treatment, brain magnetic resonance image (MRI) showed streaky bleeding in bilateral cerebellum (zebra sign), leading to a diagnosis of RCH. Close observation and repeated brain MRI imaging without specific treatments led to the absorption of bilateral cerebellar hemorrhage, and the patient was discharged with improved neurological symptoms. Repeated brain MRI scans one month after discharge showed that bilateral cerebellar hemorrhage had improved, and had disappeared one year after discharge. Conclusion We reported a rare occurrence of LPs-induced RCH presenting as isolated bilateral inferior cerebellar hemorrhage. Clinicians should be vigilant of the risk factors for RCH, closely monitoring patients' clinical symptoms and neuroimaging findings to determine the need for specialized treatment. Furthermore, this case highlights the importance of ensuring the safety of LPs and managing any potential complications appropriately

    Highly Hydrophobic Cotton Fabrics Modified by Poly(methylhydrogen)siloxane and Fluorinated Olefin: Characterization and Applications

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    Highly hydrophobic cotton fabrics were obtained with poly(methylhydrogen)siloxane (PMHS) and a further fluorinated olefin modification. The chemical structures and microstructures of PMHS-modified cotton fabrics were characterized, and application of the resultant cotton fabrics in stain resistance and oil–water separation was demonstrated. PMHS chains with very low surface energy were grafted onto cotton fabric by the dehydrogenation reaction between –Si–H of PMHS and –OH groups of cotton fabric at room temperature. The water contact angle of PMHS-modified cotton fabric was 141.7°, which provided the modified cotton fabric with good stain resistance to waterborne pollutants. The separation efficiency of diesel from water was higher than 92% for 20 repeatable separation cycles. A further improvement in stain resistance to oil was also demonstrated by a further addition reaction of 1H,1H,2H-perfluoro-1-decene with PMHS-modified cotton fabric
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