Publications by authors named "Guang Zhong Yang"

Article Synopsis
  • Shape Memory Polymers (SMPs) have great potential for medical applications, but their usage has been limited due to challenges in processing and production.
  • This study introduces a thermal drawing technique to create Shape Memory Polymer Fibers (SMPFs) that allow for programmable stiffness and shape control, specifically designed for medical devices.
  • The research explores various applications of these SMPFs in medical devices like adjustable catheters, neural interfaces, and cochlear implants, demonstrating their versatility and potential in programmable mechanical functions.
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Triple-negative breast cancer (TNBC), characterized by its aggressive metastatic propensity and lack of effective targeted therapeutic options, poses a major challenge in oncological management. A proof-of-concept neoadjuvant strategy aimed at inhibiting TNBC tumor growth and mitigating metastasis through a localized delivery of chemotherapeutics is reported in this paper. This approach addresses the limitations in payload capacity and stimuli responsiveness commonly associated with microrobotics in oncology.

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Photoacoustic microscopy (PAM) has gained increasing popularity in biomedical imaging, providing new opportunities for tissue monitoring and characterization. With the development of deep learning techniques, convolutional neural networks have been used for PAM image resolution enhancement and denoising. However, there exist several inherent challenges for this approach.

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  • Endoluminal and endocavitary interventions are gaining popularity for early intervention and precision surgery, pushing the need for advanced robotic technology.
  • A new submillimeter-scale fiber robot (~1 mm) is designed for both macro and micro manipulations, using thin optical fibers for actuation and light transmission.
  • This robot can perform precise movements across different scales, achieving accuracy in micro operations during in vivo animal studies.
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Purposes: To enhance the functional capability of MRI, this study aims to develop a novel MR elastography (MRE) sequence that achieves rapid acquisition without distortion artifacts.

Methods: A displacement-encoded stimulated echo (DENSE) with multiphase acquisition scheme was used to capture wave images. A center-out golden-angle stack-of-stars sampling pattern was introduced for improved SNR and data incoherence.

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  • * Magnetic resonance imaging (MRI) is a promising radiation-free option for cardiovascular interventions but currently lacks compatible instruments for effective use.
  • * The introduction of a new thermal drawing platform allows for the rapid development of affordable MRI-compatible catheter systems, demonstrating similar mechanical properties to existing devices and paving the way for innovation in catheter technologies for cardiovascular interventions.
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  • Implantable devices for brain-machine interfaces and neurological disorders are growing rapidly, but concerns exist about trauma and long-term safety.
  • This study introduces titanium oxynitride (TiNO) nanofilm as a biosensor that can detect acute inflammatory responses in the brain during micro-neuro-implantation.
  • The TiNO-SPR biosensor is highly sensitive to the inflammatory cytokine interleukin-6, allowing for quick assessments of inflammation during surgeries, which helps improve the safety of invasive procedures.
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Piperine, a natural amide isolated from the genus of , serves as a pharmacophore in medicinal chemistry. In this study, we synthesised and evaluated 18 novel piperine-acylhydrazone hybrids (-) for their antiproliferative activities . The structures of these hybrids were validated using H,C NMR, and HR-ESI-MS data.

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Unlabelled: Magnetic resonance elastography (MRE) of brain relies on inducing and measuring shear waves in the brain. However, studies have shown vibration could induce changes in cerebral blood flow (CBF), which has a modulation effect and can affect the biomechanical properties measured.

Objective: This work demonstrates the initial prototype of the indirect excitation method, which can generate shear waves in the brain with minimal changes in CBF.

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Background: Different MR elastography (MRE) systems may produce different stiffness measurements, making direct comparison difficult in multi-center investigations.

Purpose: To assess the repeatability and reproducibility of liver stiffness measured by three typical MRE systems.

Study Type: Prospective.

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Cerebral aneurysms and brain tumors are leading life-threatening diseases worldwide. By deliberately occluding the target lesion to reduce the blood supply, embolization has been widely used clinically to treat cerebral aneurysms and brain tumors. Conventional embolization is usually performed by threading a catheter through blood vessels to the target lesion, which is often limited by the poor steerability of the catheter in complex neurovascular networks, especially in submillimeter regions.

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One previously undescribed naphthoquinone-benzisochromanquinone dimer berpolydiquinone A (), along with two previously undescribed naphthoquinone-anthraquinone dimers berpolydiquinones B and C (-), and one previously undescribed dimeric naphthalene berpolydinaphthalene A (), were isolated from the stems and leaves of var. leioclada. The chemical structures of these compounds were determined using high-resolution electrospray ionization mass spectroscopy (HR-ESI-MS), spectroscopic data, the exciton chirality method (ECM), and quantum chemical calculation.

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Precise manipulation of flexible surgical tools is crucial in minimally invasive surgical procedures, necessitating a miniature and flexible robotic probe that can precisely direct the surgical instruments. In this work, we developed a polymer-based robotic fiber with a thermal actuation mechanism by local heating along the sides of a single fiber. The fiber robot was fabricated by highly scalable fiber drawing technology using common low-cost materials.

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Drug delivery to the brain is crucial in the treatment for central nervous system disorders. While significant progress has been made in recent years, there are still major challenges in achieving controllable drug delivery to the brain. Unmet clinical needs arise from various factors, including controlled drug transport, handling large drug doses, methods for crossing biological barriers, the use of imaging guidance, and effective models for analyzing drug delivery.

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Three new anthraquinone-benzisochromanquinone dimers polyphylldiquinones A-C (), along with three known analogs floribundiquinone A-B (-) and 7-dehydroxyventiloquinone H (), were isolated from the stems and leaves of . The chemical structures and absolute configurations of these compounds were determined using HR-ESI-MS, spectroscopic data, and electronic circular dichroism. Notably, compounds (-) are dimeric quinones that share the same benzisochromanquinone moiety, specifically identified as 7-dehydroxyventiloquinone H (), which was the first time to report as a natural product.

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Accurate navigation and targeting are critical for neurological interventions including biopsy and deep brain stimulation. Real-time image guidance further improves surgical planning and MRI is ideally suited for both pre- and intra-operative imaging. However, balancing spatial and temporal resolution is a major challenge for real-time interventional MRI (i-MRI).

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Motor Imagery (MI) Electroencephalography (EEG) is one of the most common Brain-Computer Interface (BCI) paradigms that has been widely used in neural rehabilitation and gaming. Although considerable research efforts have been dedicated to developing MI EEG classification algorithms, they are mostly limited in handling scenarios where the training and testing data are not from the same subject or session. Such poor generalization capability significantly limits the realization of BCI in real-world applications.

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Article Synopsis
  • Triterpenoid saponins have shown potential for relieving inflammatory pain, primarily by enhancing inhibitory synaptic responses and affecting capsaicin receptors.
  • The study utilized patch clamp techniques and animal experiments to identify active components and evaluate their analgesic effects.
  • Findings indicate that these saponins can improve pain relief through various mechanisms, highlighting the multi-faceted approach of traditional Chinese medicine in targeting pain management.
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  • Open international challenges are now the main way to evaluate algorithms for computer vision and image analysis, especially in pulmonary airway segmentation.
  • A new challenge, ATM'22, was organized to provide a large-scale dataset of 500 annotated CT scans to help improve algorithm performance in this area.
  • The results showed that deep learning models that enhanced topological continuity performed best, and the challenge offers an open-call design for accessing data and evaluations.
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Article Synopsis
  • Garbractin A is a complex compound with a unique dodecane structure, discovered in the fruit of a specific plant.
  • Researchers also identified five new similar compounds, known as garcibracteatones A-E.
  • The study tested these compounds' effects on insulin-resistant liver cells, finding that several increased glucose consumption, suggesting they might be useful in treating high blood sugar levels.
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The integration of machine/deep learning and sensing technologies is transforming healthcare and medical practice. However, inherent limitations in healthcare data, namely scarcity, quality, and heterogeneity, hinder the effectiveness of supervised learning techniques which are mainly based on pure statistical fitting between data and labels. In this article, we first identify the challenges present in machine learning for pervasive healthcare and we then review the current trends beyond fully supervised learning that are developed to address these three issues.

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Master-Slave control is a common mode of operation for surgical robots as it ensures that surgeons are always in control and responsible for the procedure. Most teleoperated surgical systems use low degree-of-freedom (DOF) instruments, thus facilitating direct mapping of manipulator position to the instrument pose and tip location (tip-to-tip mapping). However, with the introduction of continuum and snake-like robots with much higher DOF supported by their inherent redundant architecture for navigating through curved anatomical pathways, there is a need for developing effective kinematic methods that can actuate all the joints in a controlled fashion.

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Purpose: Endobronchial intervention requires detailed modeling of pulmonary anatomical substructure, such as lung airway and artery-vein maps, which are commonly extracted from non-contrast computed tomography (NCCT) independently using automatic segmentation approaches. We aim to make the first attempt to jointly train a CNN-based model for airway and artery-vein segmentation along with synthetic contrast-enhanced CT (CECT) generation.

Methods: A multi-task framework is proposed to simultaneously generate three segmentation maps and synthesize CECTs.

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