Publications by authors named "Yunpeng Ye"

Gypsum-based composites were prepared via a slurry casting process using construction gypsum as the binding material and poplar fibers as reinforcing material. The effects of different fiber content and curing time on the mechanical properties, water resistance, and flame retardancy of these composites were investigated, and the influence mechanism was characterized by infrared spectroscopy, scanning electron microscopy, and X-ray diffractometry. The results showed that the best composite mechanical strength was achieved with 10% poplar fiber- content, and the absolute dry flexural and compressive strengths reached 3.

View Article and Find Full Text PDF

Microscopic fringe projection profilometry (MFPP) technology is widely used in 3D measurement. The measurement precision performed by the MFPP system is closely related to the calibration accuracy. However, owing to the shallow depth of field, calibration in MFPP is frequently influenced by low-quality target images, which would generate inaccurate features and calibration parameter estimates.

View Article and Find Full Text PDF

Background: Matrix metalloproteinases (MMPs) play a key role in the pathogenesis of abdominal aortic aneurysm (AAA). Imaging aortic MMP activity, especially using positron emission tomography to access high sensitivity, quantitative data, could potentially improve AAA risk stratification. Here, we describe the design, synthesis, characterization, and evaluation in murine AAA and human aortic tissue of a first-in-class MMP-targeted positron emission tomography radioligand, Cu-RYM2.

View Article and Find Full Text PDF

Biodegradable composites were prepared from polylactic acid (PLA) and bamboo charcoal (BC) by melt blending and hot pressing. The effects of BC addition on the mechanical properties, water absorption, DMA, TGA, DSC, and CONE of BC/PLA composites were investigated. The microscopic morphology of the composites was analyzed by SEM.

View Article and Find Full Text PDF

Reed charcoal/polypropylene (RC/PP) composites were prepared by melt-blending and molding processes. The effects of RC addition (by mass fraction) on its mechanical properties were investigated and the mechanism characterized. The results showed that RC and PP were physically bonded and formed a mechanical interlocking matrix.

View Article and Find Full Text PDF

Purpose: Exploring synaptic density changes during brain growth is crucial to understanding brain development. Previous studies in nonhuman primates report a rapid increase in synapse number between the late gestational period and the early neonatal period, such that synaptic density approaches adult levels by birth. Prenatal synaptic development may have an enduring impact on postnatal brain development, but precisely how synaptic density changes in utero are unknown because current methods to quantify synaptic density are invasive and require post-mortem brain tissue.

View Article and Find Full Text PDF

The discovery of ketamine as a rapid and robust antidepressant marks the beginning of a new era in the treatment of psychiatric disorders. Ketamine is thought to produce rapid and sustained antidepressant effects through restoration of lost synaptic connections. We investigated this hypothesis in humans for the first time using positron emission tomography (PET) and [C]UCB-J-a radioligand that binds to the synaptic vesicle protein 2A (SV2A) and provides an index of axon terminal density.

View Article and Find Full Text PDF
Article Synopsis
  • Augmented reality (AR) has quickly advanced and is being used in various fields, including medicine, with a strong connection to ophthalmology because most AR systems are visually based.
  • The paper outlines the structure and essential hardware of standard AR systems, followed by a detailed look at their applications in ophthalmology, such as therapy, education, and clinical assistance.
  • Despite current challenges, particularly with hardware limitations, there's significant potential for AR in ophthalmology, especially in areas like diagnosis and protection, calling for more dedicated research and development.
View Article and Find Full Text PDF

Background: Dopaminergic mechanisms that may underlie cannabis' reinforcing effects are not well elucidated in humans. This positron emission tomography (PET) imaging study used the dopamine D receptor antagonist [C]raclopride and kinetic modelling testing for transient changes in radiotracer uptake to assess the striatal dopamine response to smoked cannabis in a preliminary sample.

Methods: PET emission data were acquired from regular cannabis users (n = 14; 7 M/7 F; 19-32 years old) over 90 min immediately after [C]raclopride administration (584 ± 95 MBq) as bolus followed by constant infusion (K = 105 min).

View Article and Find Full Text PDF

Background: Attempts to associate amyloid-β (Aβ) pathogenesis with synaptic loss in Alzheimer's disease (AD) have thus far been limited to small numbers of postmortem studies. Aβ plaque burden is not well-correlated with indices of clinical severity or neurodegeneration-at least in the dementia stage-as deposition of Aβ reaches a ceiling. In this study, we examined in vivo the association between fibrillar Aβ deposition and synaptic density in early AD using positron emission tomography (PET).

View Article and Find Full Text PDF

Macrophage elastase [matrix metalloproteinase (MMP)-12] is the most upregulated MMP in abdominal aortic aneurysm (AAA) and, hence, MMP-12-targeted imaging may predict AAA progression and rupture risk. Here, we report the design, synthesis, and evaluation of three novel hydroxamate-based selective MMP-12 inhibitors (CGA, CGA-1, and AGA) and the methodology to obtain MMP-12 selectivity from hydroxamate-based panMMP inhibitors. Also, we report two Tc-radiotracers, Tc-AGA-1 and Tc-AGA-2, derived from AGA.

View Article and Find Full Text PDF

Matrix metalloproteinase-12 (MMP-12) is highly upregulated in several inflammatory diseases, including abdominal aortic aneurysm (AAA). Here we report four novel Tc-labeled radiotracers derived from a highly selective competitive MMP-12 inhibitor. These tracers in their Tc version were assessed in vitro on a set of human metalloproteases and displayed high affinity and selectivity toward MMP-12.

View Article and Find Full Text PDF

Matrix metalloproteinases (MMPs) are involved in tissue remodeling. Accordingly, MMP inhibitors and related radiolabeled analogs are important tools for MMP-targeted imaging and therapy in a number of diseases. Herein, we report design, synthesis, and evaluation of a new Arginine-containing macrocyclic hydroxamate analog, RYM, its hydrazinonicotinamide conjugate, RYM1 and Tc-labeled analog Tc-RYM1 for molecular imaging.

View Article and Find Full Text PDF

Matrix metalloproteinases (MMPs) play a key role in abdominal aortic aneurysm (AAA) development. Accordingly, MMP-targeted imaging provides important information regarding vessel wall biology in the course of aneurysm development. Given the small size of the vessel wall and its proximity with blood, molecular imaging of aneurysm optimally requires highly sensitive tracers with rapid blood clearance.

View Article and Find Full Text PDF

Matrix metalloproteinase (MMP)-12 plays a key role in the development of aneurysm. Like other members of MMP family, MMP-12 is produced as a proenzyme, mainly by macrophages, and undergoes proteolytic activation to generate an active form. Accordingly, molecular imaging of the MMP-12 active form can inform of the pathogenic process in aneurysm.

View Article and Find Full Text PDF

In designing new tracers consisting of a small peptide conjugated to a reporter of comparable size, particular attention needs to be paid to the selection of the reporter group, which can dictate both the in vitro and the in vivo performances of the whole conjugate. In the case of fluorescent tracers, this is particularly true given the large numbers of available dye moieties differing in their structures and properties. Here, we have investigated the in vitro and in vivo properties of a novel series of MMP-12 selective probes composed of cyanine dyes varying in their structure, net charge, and hydrophilic character, tethered through a linker to a potent and specific MMP-12 phosphinic pseudopeptide inhibitor.

View Article and Find Full Text PDF

Calcific aortic valve disease (CAVD) is the most common cause of aortic stenosis. Currently, there is no non-invasive medical therapy for CAVD. Matrix metalloproteinases (MMPs) are upregulated in CAVD and play a role in its pathogenesis.

View Article and Find Full Text PDF

Unlabelled: Imaging techniques for detection of molecular and cellular processes that precede or accompany lung diseases are needed. Matrix metalloproteinases (MMPs) play key roles in the development of pulmonary pathology. The objective of this study was to investigate the feasibility of in vivo MMP-targeted molecular imaging for detection of lung inflammation and remodeling.

View Article and Find Full Text PDF

Unlabelled: Calcific aortic valve disease (CAVD) is the most common cause of aortic stenosis. Matrix metalloproteinases (MMPs) are upregulated in CAVD and contribute to valvular remodeling and calcification. We investigated the feasibility and correlates of MMP-targeted molecular imaging for detection of valvular biology in CAVD.

View Article and Find Full Text PDF

Background: Abdominal aortic aneurysm (AAA) rupture risk is currently determined based on size and symptoms. This approach does not address the rupture risk associated with small aneurysms. Given the role of matrix metalloproteinases (MMPs) in AAA weakening and rupture, we investigated the potential of MMP-targeted imaging for detection of aneurysm biology and prediction of outcome in a mouse model of AAA with spontaneous rupture.

View Article and Find Full Text PDF

A first-in-human clinical trial of ultrasmall inorganic hybrid nanoparticles, "C dots" (Cornell dots), in patients with metastatic melanoma is described for the imaging of cancer. These renally excreted silica particles were labeled with (124)I for positron emission tomography (PET) imaging and modified with cRGDY peptides for molecular targeting. (124)I-cRGDY-PEG-C dot particles are inherently fluorescent, containing the dye, Cy5, so they may be used as hybrid PET-optical imaging agents for lesion detection, cancer staging, and treatment management in humans.

View Article and Find Full Text PDF

Photodynamic therapy (PDT) is an established treatment modality, used mainly for anticancer therapy that relies on the interaction of photosensitizer, light and oxygen. For the treatment of pathologies in certain anatomical sites, improved targeting of the photosensitizer is necessary to prevent damage to healthy tissue. We report on a novel dual approach of targeted PDT (vascular and cellular targeting) utilizing the expression of neuropeptide somatostatin receptor (sst2) on tumor and neovascular-endothelial cells.

View Article and Find Full Text PDF

A new near-infrared fluorescent compound containing two cyclic RGD motifs, cypate-[c(RGDfK)](2) (1), was synthesized based on a carbocyanine fluorophore bearing two carboxylic acid groups (cypate) for integrin α(v)β(3)-targeting. Compared with its monovalent counterpart cypate-c(RGDfK) (2), 1 exhibited remarkable improvements in integrin α(v)β(3) binding affinity and tumor uptake in nude mice of A549. The results suggest that cypate-linked divalent ligands can serve as an important molecular platform for exploring receptor-targeted optical imaging and treatment of various diseases.

View Article and Find Full Text PDF

Purpose: Near-infrared fluorescence (NIRF) imaging is an attractive technique for studying diseases at the molecular level in vivo. Glucose transporters are often used as targets for in vivo imaging of tumors. The efficiency of a tumor-seeking fluorescent probe can be enhanced by attaching one or more glucosamine (GlcN) moieties.

View Article and Find Full Text PDF

Optical imaging has emerged as a powerful modality for studying molecular recognitions and molecular imaging in a noninvasive, sensitive, and real-time way. Some advantages of optical imaging include cost-effectiveness, convenience, and non-ionization safety as well as complementation with other imaging modalities such as positron emission tomography (PET), single-photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI). Over the past decade, considerable advances have been made in tumor optical imaging by targeting integrin receptors in preclinical studies.

View Article and Find Full Text PDF