481 research outputs found

    Dual-view photoacoustic microscopy for quantitative cell nuclear imaging

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    Optical-resolution photoacoustic microscopy (OR-PAM) is an emerging imaging modality for studying biological tissues. However, in conventional single-view OR-PAM, the lateral and axial resolutions—determined optically and acoustically, respectively—are highly anisotropic. In this Letter, we introduce dual-view OR-PAM to improve axial resolution, achieving three-dimensional (3D) resolution isotropy. We first use 0.5 μm polystyrene beads and carbon fibers to validate the resolution isotropy improvement. Imaging of mouse brain slices further demonstrates the improved resolution isotropy, revealing the 3D structure of cell nuclei in detail, which facilitates quantitative cell nuclear analysis

    Dual-view photoacoustic microscopy for quantitative cell nuclear imaging

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    Optical-resolution photoacoustic microscopy (OR-PAM) is an emerging imaging modality for studying biological tissues. However, in conventional single-view OR-PAM, the lateral and axial resolutions—determined optically and acoustically, respectively—are highly anisotropic. In this Letter, we introduce dual-view OR-PAM to improve axial resolution, achieving three-dimensional (3D) resolution isotropy. We first use 0.5 μm polystyrene beads and carbon fibers to validate the resolution isotropy improvement. Imaging of mouse brain slices further demonstrates the improved resolution isotropy, revealing the 3D structure of cell nuclei in detail, which facilitates quantitative cell nuclear analysis

    Quantitative cell nuclear imaging by dual-view optical-resolution photoacoustic microscopy

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    An estimated ~250,000 new cases of both invasive and non-invasive breast cancer were diagnosed in US women almost every year. To reduce the local recurrence rate, the breast conserving surgery (BCS) is widely used as the initial therapy, which is to excise the tumor with a rim of normal surrounding tissue such that no cancer cells remain at the cut margin, Patients with positive margin commonly require a second surgical procedure to obtain clear margins. To this end, optical-resolution photoacoustic microscopy (OR-PAM) with ultraviolet (UV) laser illumination (OR-UV-PAM) has been developed for providing label-free, high-resolution, and histology like imaging of fixed, unprocessed breast tissue. To further improve the performance of OR-UV-PAM, here, we introduce dual-view UV-PAM (DV-UV-PAM) to significantly improve the axial resolution, achieving three-dimensional (3D) resolution isotropy. We first use 0.5 μm polystyrene beads and carbon fibers to validate the resolution isotropy improvement. Imaging of mouse brain slices further demonstrates the improved resolution isotropy, revealing the 3D structure of cell nuclei in detail, which facilitates quantitative cell nuclear analysis

    Soft Actuators and Robotic Devices for Rehabilitation and Assistance

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    Soft actuators and robotic devices have been increasingly applied to the field of rehabilitation and assistance, where safe human and machine interaction is of particular importance. Compared with their widely used rigid counterparts, soft actuators and robotic devices can provide a range of significant advantages; these include safe interaction, a range of complex motions, ease of fabrication and resilience to a variety of environments. In recent decades, significant effort has been invested in the development of soft rehabilitation and assistive devices for improving a range of medical treatments and quality of life. This review provides an overview of the current state-of-the-art in soft actuators and robotic devices for rehabilitation and assistance, in particular systems that achieve actuation by pneumatic and hydraulic fluid-power, electrical motors, chemical reactions and soft active materials such as dielectric elastomers, shape memory alloys, magnetoactive elastomers, liquid crystal elastomers and piezoelectric materials. Current research on soft rehabilitation and assistive devices is in its infancy, and new device designs and control strategies for improved performance and safe human-machine interaction are identified as particularly untapped areas of research. Finally, insights into future research directions are outlined

    Decision Tree Classification Model In Water Supply Network

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    With the service life of water supply network (WSN) growth, the growing phenomenon of aging pipe network has become exceedingly serious. As urban water supply network is hidden underground asset, it is difficult for monitoring staff to make a direct classification towards the faults of pipe network by means of the modern detecting technology. In this paper, based on the basic property data (e.g. diameter, material, pressure, distance to pump, distance to tank, load, etc.) of water supply network, decision tree algorithm (C4.5) has been carried out to classify the specific situation of water supply pipeline. Part of the historical data was used to establish a decision tree classification model, and the remaining historical data was used to validate this established model. Adopting statistical methods were used to access the decision tree model including basic statistical method, Receiver Operating Characteristic (ROC) and Recall-Precision Curves (RPC). These methods has been successfully used to assess the accuracy of this established classification model of water pipe network. The purpose of classification model was to classify the specific condition of water pipe network. It is important to maintain the pipeline according to the classification results including asset unserviceable (AU), near perfect condition (NPC) and serious deterioration (SD). Finally, this research focused on pipe classification which plays a significant role in maintaining water supply networks in the future

    The bidirectional interation between pancreatic cancer and diabetes

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    Abstract The bidirectional interation between pancreatic cancer (PanCa) and diabetes has been confirmed by epidemiological studies, which provide evidence-based medical support for further research into the mechanisms involved in the interaction. We reviewed the literature regarding the role of diabetes in the generation and progression of PanCa and the mechanism by which PanCa induces diabetes for its malignant progression. The effect of antidiabetic drugs on the occurrence and prognosis of PanCa was also reviewed. Diabetes may directly promote the progression of PanCa by pancreatic duct enlargement and hypertension, as well as by enabling an increased tumor volume. Hyperinsulinemia, insulin resistance, cytokines, hyperglycemia and genotype change are also important factors in the progression of PanCa with diabetes. Hyperglycemia may be the first clinical manifestation and is helpful in the early diagnosis of PanCa. Furthermore, antidiabetic drugs can have different effects on the occurrence and prognosis of PanCa. The bidirectional interation between PanCa and diabetes is involved in the occurrence, proliferation, invasion, metastasis and prognosis of PanCa with diabetes. The discovery of biomarkers for the early diagnosis of PanCa, as well as the novel usage of metformin for its antitumor effects and determining the potential mechanisms of these effects, may be the next direction for PanCa research and treatment.</p

    Immobilization of Horseradish Peroxidase on Multi-Armed Magnetic Graphene Oxide Composite: Improvement of Loading Amount and Catalytic Activity

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    U ovom je radu po prvi puta sintetiziran novi tip zvjezdastog kompozita polietilen glikola (PEG) s grafen oksidom (GO@Fe3O4@6arm-PEG-NH2), te je upotrijebljen kao podloga za imobilizaciju peroksidaze iz hrena. Udjel peroksidaze iz hrena na kompozitu bio je relativno velik (186,34 mg/g) zbog velikog broja amino skupina iz 6arm-PEG-NH2 prisutnih na površini nosača. Brzina razgradnje fenolnih spojeva bila je bitno veća (95,4 %) zbog sinergijskog učinka slobodne peroksidaze (45,4 %) i podloge (13,6 %). Nakon imobilizacije povećala se toplinska stabilnost, te su se produljili vrijeme trajanja i iskoristivost enzima u usporedbi sa slobodnim enzimom. Imobilizirana peroksidaza je zadržala više od 68,1 % aktivnosti i nakon što je upotrijebljena osam puta. Rezultati pokazuju da se zvjezdasti magnetizirani kompozit može uspješno primijeniti za imobilizaciju enzima.In this study, a novel type of multi-armed polymer (poyltehylene glycol, PEG) magnetic graphene oxide (GO) composite (GO@Fe3O4@6arm-PEG-NH2) has been synthesized as a support for immobilization of horseradish peroxidase (HRP) for the first time. The loading amount of HRP was relatively high (186.34 mg/g) due to the surface of carrier material containing a large amount of amino groups from 6arm-PEG-NH2, but degradation rate of phenols was also much higher (95.4 %), which is attributed to the synergistic effect between the free HRP (45.4 %) and the support material of GO@Fe3O4@6arm-PEG-NH2 (13.6 %). Compared with the free enzyme, thermal, storage and operational stability of the immobilized HRP improved. The immobilized HRP still retained over 68.1 % activity after being reused 8 times. These results suggest that the multi-armed magnetic composite has good application prospect for enzyme immobilization
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