330 research outputs found

    Optical Tweezers in Biotechnology

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    Three-dimensional optical manipulation of microparticles, cells, and biomolecules in a noncontact and noninvasive manner is crucial for biophotonic, nanophotonic, and biomedical fields. Optical tweezers, as a standard optical manipulation technique, have some limitations in precise manipulation of micro-objects in microfluidics and in vivo because of their bulky lens system and limited penetration depth. Moreover, when applied for trapping nanoscale objects, especially with sizes smaller than 100 nm, the strength of optical tweezers becomes significantly weak due to the diffraction limit of light. The emerging near-field methods, such as plasmon tweezers and photonic crystal resonators, have enabled surpassing of the diffraction limit. However, these methods msay lead to local heating effects that will damage the biological specimens and reduce the trapping stability. Furthermore, the available near-field techniques rely on complex nanostructures fixed on substrates, which are usually used for 2D manipulation. The optical tweezers are of great potential for the applications including nanostructure assembly, cancer cell sorting, targeted drug delivery, single-molecule studies, and biosensing

    Simplified analytical model and balanced design approach for light-weight wood-based structural panel in bending

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    AbstractThis paper presents a simplified analytical model and balanced design approach for modeling light-weight wood-based structural panels in bending. Because many design parameters are required to input for the model of finite element analysis (FEA) during the preliminary design process and optimization, the equivalent method was developed to analyze the mechanical performance of panels based on experimental results. The bending deflection, normal strain and shear strain of the panels with various configurations were investigated using four point bending test. The results from the analytical model matched well with the experimental data, especially, the prediction for maximum deflection of the panels under failure load. The normal strain and shear strain calculated by the model also agreed with the experimental data. The failure criterion was determined by the failure modes using a 3-dimensional diagram with apparent normal and shear strain. For demonstration, panels 1 and 2 with a fixed core were modeled using the balanced design approach for optimal face thickness. The results showed that both the 3-dimensional diagram and analytical model provided similar thickness results, which were verified by the FEA for wood-based structural panels

    DiffuSeq: Sequence to Sequence Text Generation with Diffusion Models

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    Recently, diffusion models have emerged as a new paradigm for generative models. Despite the success in domains using continuous signals such as vision and audio, adapting diffusion models to natural language is under-explored due to the discrete nature of texts, especially for conditional generation. We tackle this challenge by proposing DiffuSeq: a diffusion model designed for sequence-to-sequence (Seq2Seq) text generation tasks. Upon extensive evaluation over a wide range of Seq2Seq tasks, we find DiffuSeq achieving comparable or even better performance than six established baselines, including a state-of-the-art model that is based on pre-trained language models. Apart from quality, an intriguing property of DiffuSeq is its high diversity during generation, which is desired in many Seq2Seq tasks. We further include a theoretical analysis revealing the connection between DiffuSeq and autoregressive/non-autoregressive models. Bringing together theoretical analysis and empirical evidence, we demonstrate the great potential of diffusion models in complex conditional language generation tasks. Code is available at \url{https://github.com/Shark-NLP/DiffuSeq}Comment: ICLR 2023 camera read

    Queuing Game Theory Based Optimal Routing Scheme for Heterogeneous Users over Space Information Networks

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    An optimal routing scheme in space information networks was presented to balance network loads for heterogeneous users. According to the competition among the nodes, the model was built based on queuing game theory. The virtual routing platform was in charge of resources allocation and route selection. It got user’s gain to decide which node the user joined in. Owning to the existing of heterogeneous users, an optimal admission fee needed to be obtained to avoid congestion. In our model, firstly, the whole welfare of the system was formulated. Then the optimal admission fee was calculated through maximizing the whole welfare. Meanwhile, the average maximum queue length was generated to set the buffer space of the node. At last, a routing factor was introduced into the route algorithm in order that the optimal routing could be selected by heterogeneous users. As a result, the system welfare reaches the maximum

    The Role of Postoperative Radiotherapy on Stage N2 Non-small Cell Lung Cancer

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    Background and objective The clinical value of postoperative radiotherapy (PORT) in stage N2 nonsmall-cell lung cancer (NSCLC) is controversy. The aim of this study is to analyze the efficacy of PORT in subgroup of stage N2 NSCLC, which can help clinicians to choose proper patients for PORT. Methods Clinical data of 359 patients with stage N2 NSCLC treated with radical surgery between Mar. 2000 and Jul. 2005 were retrospectively reviewed. Two hundred and seven patients received adjuvant chemotherapy and one hundred and four patients received adjuvant radiotherapy. First, the group of patients were analyzed to evaluate the factors affecting the overall survival. The all patients were divided based on tumor size and the number of lymph node metastasis station (single station or multiple station) so as to evaluate the role of PORT. The endpoint was overall survival (OS) and local recurrence-free survival (LRFS). Kaplan-Meier method was used to calculate the OS, LRFS and Log-rank was used to compare the difference in OS and LRFS between different groups. Results The median duration of follow-up was 2.3 years. 224 patients died. The median survival was 1.5 years and 1, 3, 5-year survival were 78%, 38% and 26%. Univariate analysis showed tumor size, the number of lymph node metastasis station and PORT were correlated with OS. Among patients, 5-year survival rates in PORT and non-PORT were 29% and 24% (P=0.047) respectively. In subgroups, PORT was related with high survival in patients with multiple station N2 compared to non-PORT: 36% vs 20% (P=0.013) and 33% vs 15% (P=0.002) in patients in patients with tumor size > 3 cm. Also, it was related with low local recurrence compared to non-PORT: 65% vs 48% (P=0.006) and 62% vs 48% (P=0.033). Conclusion PORT can improve overall survival for N2 NSCLC, especially the patients with the factors as follows: tumor size > 3 cm and multiple station N2 can benefit from PORT more or less

    <em>Fusarium graminearum</em> Species Complex and Trichothecene Genotype

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    The fungal phytopathogen in Fusarium species can cause Fusarium head blight of wheat, barley, oats, and other small cereal grain crops worldwide. Most importantly, these fungi can produce different kinds of mycoxins, and they are harmful to humans and animal health. FAO reported that approximately 25% of the world’s grains were contaminated by mycotoxins annually. This chapter will focus on several topics as below: (1) composition of Fusarium graminearum species complex; (2) genotype determination of Fusarium graminearum species complex strains from different hosts and their population structure changes; (3) genetic approaches to genotype determination in type B-trichothecene producing Fusaria fungi; and (4) some newly identified trichothecene mycotoxins, their toxicity, and distribution of the producers

    Potential therapeutic effects of Chinese meteria medica in mitigating drug-induced acute kidney injury

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    Drug-induced acute kidney injury (DI-AKI) is one of the leading causes of kidney injury, is associated with high mortality and morbidity, and limits the clinical use of certain therapeutic or diagnostic agents, such as antineoplastic drugs, antibiotics, immunosuppressants, non-steroidal anti-inflammatory drugs, and contrast media. In recent years, numerous studies have shown that many Chinese meteria medica, metabolites derived from botanical drugs, and Chinese medicinal formulas confer protective effects against DI-AKI by targeting a variety of cellular or molecular mechanisms, such as oxidative stress, inflammatory, cell necrosis, apoptosis, and autophagy. This review summarizes the research status of common DI-AKI with Chinese meteria medica interventions, including cisplatin, gentamicin, contrast agents, methotrexate, and acetaminophen. At the same time, this review introduces the metabolites with application prospects represented by ginseng saponins, tetramethylpyrazine, panax notoginseng saponins, and curcumin. Overall, this review provides a reference for the development of promising nephroprotectants

    Changes in the Expression of miR-381 and miR-495 Are Inversely Associated with the Expression of the MDR1 Gene and Development of Multi-Drug Resistance

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    Multidrug resistance (MDR) frequently develops in cancer patients exposed to chemotherapeutic agents and is usually brought about by over-expression of P-glycoprotein (P-gp) which acts as a drug efflux pump to reduce the intracellular concentration of the drug(s). Thus, inhibiting P-gp expression might assist in overcoming MDR in cancer chemotherapy. MiRNAome profiling using next-generation sequencing identified differentially expressed microRNAs (miRs) between parental K562 cells and MDR K562 cells (K562/ADM) induced by adriamycin treatment. Two miRs, miR-381 and miR-495, that were strongly down-regulated in K562/ADM cells, are validated to target the 3'-UTR of the MDR1 gene. These miRs are located within a miR cluster located at chromosome region 14q32.31, and all miRs in this cluster appear to be down-regulated in K562/ADM cells. Functional analysis indicated that restoring expression of miR-381 or miR-495 in K562/ADM cells was correlated with reduced expression of the MDR1 gene and its protein product, P-gp, and increased drug uptake by the cells. Thus, we have demonstrated that changing the levels of certain miR species modulates the MDR phenotype in leukemia cells, and propose further exploration of the use of miR-based therapies to overcome MDR.The authors would like to declare that we received funding from a commercial source, i.e. Bioplatforms Australia. This does not alter the authors' adherence to all PLOS ONE policies on sharing data and materials

    The next widespread bamboo flowering poses a massive risk to the giant panda

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    The IUCN Red List has downgraded several species from “endangered” to “vulnerable” that still have largely unknown extinction risks. We consider one of those downgraded species, the giant panda, a bamboo specialist. Massive bamboo flowering could be a natural disaster for giant pandas. Using scenario analysis, we explored possible impacts of the next bamboo flowering in the Qinling and Minshan Mountains that are home to most giant pandas. Our results showed that the Qinling Mountains could experience large-scale bamboo flowering leading to a high risk of widespread food shortages for the giant pandas by 2020. The Minshan Mountains could similarly experience a large-scale bamboo flowering with a high risk for giant pandas between 2020 and 2030 without suitable alternative habitat in the surrounding areas. These scenarios highlight thus-far unforeseen dangers of conserving giant pandas in a fragmented habitat. We recommend advance measures to protect giant panda from severe population crashes when flowering happens. This study also suggests the need to anticipate and manage long-term risks to other downgraded species
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