385 research outputs found

    Global exponential stability of impulsive dynamical systems with distributed delays

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    In this paper, the global exponential stability of dynamical systems with distributed delays and impulsive effect is investigated. By establishing an impulsive differential-integro inequality, we obtain some sufficient conditions ensuring the global exponential stability of the dynamical system. Three examples are given to illustrate the effectiveness of our theoretical results

    HCDG: A Hierarchical Consistency Framework for Domain Generalization on Medical Image Segmentation

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    Modern deep neural networks struggle to transfer knowledge and generalize across diverse domains when deployed to real-world applications. Currently, domain generalization (DG) is introduced to learn a universal representation from multiple domains to improve the network generalization ability on unseen domains. However, previous DG methods only focus on the data-level consistency scheme without considering the synergistic regularization among different consistency schemes. In this paper, we present a novel Hierarchical Consistency framework for Domain Generalization (HCDG) by integrating Extrinsic Consistency and Intrinsic Consistency synergistically. Particularly, for the Extrinsic Consistency, we leverage the knowledge across multiple source domains to enforce data-level consistency. To better enhance such consistency, we design a novel Amplitude Gaussian-mixing strategy into Fourier-based data augmentation called DomainUp. For the Intrinsic Consistency, we perform task-level consistency for the same instance under the dual-task scenario. We evaluate the proposed HCDG framework on two medical image segmentation tasks, i.e., optic cup/disc segmentation on fundus images and prostate MRI segmentation. Extensive experimental results manifest the effectiveness and versatility of our HCDG framework.Comment: this paper is currently not publishe

    Advances in Assistive Electronic Device Solutions for Urology

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    Recent technology advances have led urology to become one of the leading specialities to utilise novel electronic systems to manage urological ailments. Contemporary bladder management strategies such as urinary catheters can provide a solution but leave the user mentally and physically debilitated. The unique properties of modern electronic devices, i.e., flexibility, stretchability, and biocompatibility, have allowed a plethora of new technologies to emerge. Many novel electronic device solutions in urology have been developed for treating impaired bladder disorders. These disorders include overactive bladder (OAB), underactive bladder (UAB) and other-urinary-affecting disorders (OUAD). This paper reviews common causes and conservative treatment strategies for OAB, UAB and OUAD, discussing the challenges and drawbacks of such treatments. Subsequently, this paper gives insight into clinically approved and research-based electronic advances in urology. Advances in this area cover bladder-stimulation and -monitoring devices, robot-assistive surgery, and bladder and sphincter prosthesis. This study aims to introduce the latest advances in electronic solutions for urology, comparing their advantages and disadvantages, and concluding with open problems for future urological device solutions

    Molecular mechanisms of RET receptor-mediated oncogenesis in multiple endocrine neoplasia 2

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    Multiple endocrine neoplasia type 2 is an inherited cancer syndrome characterized by tumors of thyroid and adrenal tissues. Germline mutations of the REarranged during Transfection (RET) proto-oncogene, leading to its unregulated activation, are the underlying cause of this disease. Multiple endocrine neoplasia type 2 has been a model in clinical cancer genetics, demonstrating how knowledge of the genetic basis can shape the diagnosis and treatment of the disease. Here, we discuss the nature and effects of the most common recurrent mutations of RET found in multiple endocrine neoplasia type 2. Current understanding of the molecular mechanisms of RET mutations and how they alter the structure and function of the RET protein leading to its aberrant activation, and the effects on RET localization and signaling are described

    Concomitant pulmonary and thyroid tumors identified by FDG PET/CT and immunohistochemical techniques

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    <p>Abstract</p> <p>Background</p> <p>The exact diagnosis of double primary papillary adenocarcinoma of thyroid and lung is even rarer, to our knowledge no report in the literature by [<sup>18</sup>F]-2-fluoro-2-deoxy-D-glucose-positron emission tomography/X-ray CT(FDG PET/CT) with surgical specimens immunohistochemistry(IHC). We report a patient with abnormal FDG PET/CT in thyroid and lung, this unusual presentation may lead to misdiagnosis without surgical specimens IHC.</p> <p>Case presentation</p> <p>A 56-year-old man with coughing three months. FDG PET/CT was performed, and resection specimens of lung and thyroid were detected by hematoxylin eosin staining (HE) and IHC. PET/CT: lung tumor SUVmax: 3.69, delay: 5.17; and thyroid tumor SUVmax 19.97. HE reveal papillary adenocarcinoma, but histological differentiation of primary pulmonary adenocarcinoma from metastatic adenocarcinoma is sometimes difficult because of their phenotypic similarities. So IHC was performed, the IHC of lung tumor: cytokeratin 20 (CK20)(-), thyroglobulin(Tg)(-), cytokeratin7(CK7)(+), thyroid transcription factor-1 (TTF-1)(+); thyroid tumor: CK7(+), TTF-1(+), thyroglobulin (+), CK20(-). Therefore, the final diagnosis was double primary adenocarcinomas of thyroid and lung.</p> <p>Conclusion</p> <p>FDG PET/CT has preliminary diagnostic capacity of multiple primary tumors; the final diagnosis should be adopted for specimens after tumor-specific markers IHC to obtain. Consequently, effective therapeutic approaches can be designed and conducted.</p

    HOX gene complement and expression in the planarian Schmidtea mediterranea

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    Abstract Background Freshwater planarians are well known for their regenerative abilities. Less well known is how planarians maintain spatial patterning in long-lived adult animals or how they re-pattern tissues during regeneration. HOX genes are good candidates to regulate planarian spatial patterning, yet the full complement or genomic clustering of planarian HOX genes has not yet been described, primarily because only a few have been detectable by in situ hybridization, and none have given morphological phenotypes when knocked down by RNAi. Results Because the planarian Schmidtea mediterranea (S. mediterranea) is unsegmented, appendage less, and morphologically simple, it has been proposed that it may have a simplified HOX gene complement. Here, we argue against this hypothesis and show that S. mediterranea has a total of 13 HOX genes, which represent homologs to all major axial categories, and can be detected by whole-mount in situ hybridization using a highly sensitive method. In addition, we show that planarian HOX genes do not cluster in the genome, yet 5/13 have retained aspects of axially restricted expression. Finally, we confirm HOX gene axial expression by RNA deep-sequencing 6 anterior–posterior “zones” of the animal, which we provide as a dataset to the community to discover other axially restricted transcripts. Conclusions Freshwater planarians have an unappreciated HOX gene complexity, with all major axial categories represented. However, we conclude based on adult expression patterns that planarians have a derived body plan and their asexual lifestyle may have allowed for large changes in HOX expression from the last common ancestor between arthropods, flatworms, and vertebrates. Using our in situ method and axial zone RNAseq data, it should be possible to further understand the pathways that pattern the anterior–posterior axis of adult planarians

    Study on polyurethane-based porous materials and their adsorption properties

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    The flexible superhydrophobic thermoplastic polyurethane(TPU) porous material was prepared by heat-induced phase separation method with two cooling steps. The influence of the preparation process on the microstructure of the material was discussed in depth. The microstructure, hydrophobicity and specific surface area of porous TPU materials were analyzed in detail. The surface wettability, separation selectivity, saturated adsorption capacity and adsorption rate, mechanical properties, environmental adaptability and cyclic properties of porous TPU materials were studied.The results show that the TPU-8% porous monolithic material prepared by heat-induced phase separation method shows good performance when the polymer concentration is 8%, the phase separation temperature is 0°C, the phase separation time is 30min, and the mixing solvent ratio is 9:1

    Impact of biogenic SOA loading on the molecular composition of wintertime PM2.5 in urban Tianjin: an insight from Fourier transform ion cyclotron resonance mass spectrometry

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    Biomass burning is one of the key sources of urban aerosols in the North China Plain, especially in winter when the impact of secondary organic aerosols (SOA) formed from biogenic volatile organic compounds (BVOCs) is generally considered to be minor. However, little is known about the influence of biogenic SOA loading on the molecular composition of wintertime organic aerosols. Here, we investigated the water-soluble organic compounds in fine particles (PM2.5) from urban Tianjin by ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Our results show that most of the CHO and CHON compounds were derived from biomass burning; they contain O-poor and highly unsaturated compounds with aromatic rings, which are sensitive to photochemical reactions, and some of which probably contribute to light-absorbing chromophores. Under moderate to high SOA loading conditions, the nocturnal chemistry is more efficient than photooxidation to generate secondary CHO and CHON compounds with high oxygen content. Under low SOA-loading, secondary CHO and CHON compounds with low oxygen content are mainly formed by photochemistry. Secondary CHO compounds are mainly derived from oxidation of monoterpenes. But nocturnal chemistry may be more productive to sesquiterpene-derived CHON compounds. In contrast, the number- and intensity-weight of S-containing groups (CHOS and CHONS) increased significantly with the increase of biogenic SOA-loading, which agrees with the fact that a majority of the S-containing groups are identified as organosulfates and nitrooxy-organosulfates that are derived from the oxidation of BVOCs. Terpenes may be potential major contributors to the chemical diversity of organosulfates and nitrooxy-organosulfates under photo-oxidation. While the nocturnal chemistry is more beneficial to the formation of organosulfates and nitrooxy-organosulfates under low SOA-loading. The SOA-loading is an important factor associating with the oxidation degree, nitrate group content and chemodiversity of nitrooxy-organosulfates. Furthermore, our study suggests that the hydrolysis of nitrooxy-organosulfates is a possible pathway for the formation of organosulfates.</p

    Progress Towards the Miniaturization of an Ultrasonic Scalpel for Robotic Endoscopic Surgery Using Mn:PIN-PMN-PT High Performance Piezocrystals

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    Mn:PIN-PMN-PT piezocrystals are under consideration for potential use in miniaturised ultrasonic scalpels for robotic minimally-invasive surgery where small size and light weight may be advantageous. Electromechanical coupling coefficient k &gt; 0.9 for both [001] and [011] poled Mn:PIN-PMN-PT was calculated, confirming the well-recognized higher efficiency of this material when compared to standard piezoceramics. Novel transducer design strategies have been explored, and outcomes are discussed. The introduction of components with additional compliance in a standard d 31 mode transducer has been shown to drop the resonant frequency of the first longitudinal mode by more than 17%, with more than 75% improvement in tip/blade displacement. Results suggest that the combination of high performance piezocrystals with highly compliant components may be a useful route to follow to achieve our miniaturisation target
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