α-Mangostin Induces Apoptosis and Suppresses Differentiation of 3T3-L1 Cells via Inhibiting Fatty Acid Synthase

α-Mangostin, isolated from the hulls of Garcinia mangostana L., was found to have in vitro cytotoxicity against 3T3-L1 cells as well as inhibiting fatty acid synthase (FAS, EC 2.3.1.85). Our studies showed that the cytotoxicity of α-mangostin with IC50 value of 20 µM was incomplicated in apoptotic events including increase of cell membrane permeability, nuclear chromatin condensation and mitochondrial membrane potential (ΔΨm) loss. This cytotoxicity was accompanied by the reduction of FAS activity in cells and could be rescued by 50 µM or 100 µM exogenous palmitic acids, which suggested that the apoptosis of 3T3-L1 preadipocytes induced by α-mangostin was via inhibition of FAS. Futhermore, α-mangostin could suppress intracellular lipid accumulation in the differentiating adipocytes and stimulated lipolysis in mature adipocytes, which was also related to its inhibition of FAS. In addition, 3T3-L1 preadipocytes were more susceptible to the cytotoxic effect of α-mangostin than mature adipocytes. Further studies showed that α-mangostin inhibited FAS probably by stronger action on the ketoacyl synthase domain and weaker action on the acetyl/malonyl transferase domain. These findings suggested that α-mangostin might be useful for preventing or treating obesity

Boundary-RL: Reinforcement Learning for Weakly-Supervised Prostate Segmentation in TRUS Images

We propose Boundary-RL, a novel weakly supervised segmentation method that utilises only patch-level labels for training. We envision the segmentation as a boundary detection problem, rather than a pixel-level classification as in previous works. This outlook on segmentation may allow for boundary delineation under challenging scenarios such as where noise artefacts may be present within the region-of-interest (ROI) boundaries, where traditional pixel-level classification-based weakly supervised methods may not be able to effectively segment the ROI. Particularly of interest, ultrasound images, where intensity values represent acoustic impedance differences between boundaries, may also benefit from the boundary delineation approach. Our method uses reinforcement learning to train a controller function to localise boundaries of ROIs using a reward derived from a pre-trained boundary-presence classifier. The classifier indicates when an object boundary is encountered within a patch, as the controller modifies the patch location in a sequential Markov decision process. The classifier itself is trained using only binary patch-level labels of object presence, which are the only labels used during training of the entire boundary delineation framework, and serves as a weak signal to inform the boundary delineation. The use of a controller function ensures that a sliding window over the entire image is not necessary. It also prevents possible false-positive or -negative cases by minimising number of patches passed to the boundary-presence classifier. We evaluate our proposed approach for a clinically relevant task of prostate gland segmentation on trans-rectal ultrasound images. We show improved performance compared to other tested weakly supervised methods, using the same labels e.g., multiple instance learning.Comment: Accepted to MICCAI Workshop MLMI 2023 (14th International Conference on Machine Learning in Medical Imaging

Landslide Movement Monitoring with InSAR Technologies

Synthetic aperture radar interferometry (InSAR) is a technology that has been widely used in many areas, such as topographic mapping, land and resource survey, geological exploration, disaster prevention and mitigation, volcanic and seismic monitor and so on. Landslide, as a representative geohazard, include a wide range of phenomena involving downhill ground movement. InSAR, a technology which can measure surface deformation at the millimeter level over serveral days or years, is suitable to detect landslides with chronical and widespread movements. In this chapter, we introduce main process methods of InSAR data, including Persistent Scatter Interferometry (PSInSAR) and Distributed Scatter Interferometry (DSInSAR). A study area, Daguan County Town, one of the most landslide-prone areas in China is induced to demonstrate the practicability of InSAR in detecting landslides. Combined InSAR results with geological, geotechnical and meterological data, the distribution of landslide in Daguan County in spatial and temporal dimensions would be displayed. We also coupling numerical modeling and InSAR for characterizing landslide movements under multiple loads. The numerical results revealed that body loads dominated the cumulative downhill movements by squeezing water and air from voids, and precipitation caused seasonal movements with the direction perpendicular to the slope surface

Discrimination and quantification of scar tissue by Mueller matrix imaging with machine learning

Scarring is one of the biggest areas of unmet need in the long-term success of glaucoma filtration surgery. Quantitative evaluation of the scar tissue and the post-operative structure with micron scale resolution facilitates development of anti-fibrosis techniques. However, the distinguishment of conjunctiva, sclera and the scar tissue in the surgical area still relies on pathologists’ experience. Since polarized light imaging is sensitive to anisotropic properties of the media, it is ideal for discrimination of scar in the subconjunctival and episcleral area by characterizing small differences between proportion, organization and the orientation of the fibers. In this paper, we defined the conjunctiva, sclera, and the scar tissue as three target tissues after glaucoma filtration surgery and obtained their polarization characteristics from the tissue sections by a Mueller matrix microscope. Discrimination score based on parameters derived from Mueller matrix and machine learning was calculated and tested as a diagnostic index. As a result, the discrimination score of three target tissues showed significant difference between each other ([Formula: see text]). The visualization of the discrimination results showed significant contrast between target tissues. This study proved that Mueller matrix imaging is effective in ocular scar discrimination and paves the way for its application on other forms of ocular fibrosis as a substitute or supplementary for clinical practice

A high resolution method for C-14 analysis of a coral from South China Sea: Implication for "AD 775" C-14 event

A pre-heating method that improves the background and precision of C-14 dating significantly was applied for fossil coral dating with high resolution in our lab in Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIGCAS). The reaction tube is heated under 300 degrees C in a vacuum line before it is used for graphitization. The method can reduce the contamination absorbed in TiH2, Zn and Fe power placed in the graphitization tube. With the pre-heating and average drilling method, bi-weekly resolution C-14 dating in a fossil coral is carried out to investigate the "AD 775 C-14 spike event". Different from the tree ring C-14 archives with the C-14 spike of similar to 15 parts per thousand (Delta C-14), the C-14 spike in the coral shows an abrupt peak of 45 parts per thousand and two smaller spikes of Delta C-14 > 20 parts per thousand in half a year in AD 776. And then, the C-14 content in coral decreases gradually in AD 777. The peak time of the C-14 spike event likely occurs in the summer of AD 776 according to the delta O-18 variation in coral. High-resolution dating of C-14 in coral provides not only a more detail process of the event than that from tree rings, but also the first report of the event from sea ecosystem. Both of them suggest an extraterrestrial origin of the event cause. (C) 2015 Elsevier B.V. All rights reserved

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From the 16th International Radiocarbon Conference held in Gronigen, Netherlands, June 16-20, 1997.Accurate radiocarbon ages were obtained from terrestrial moss from two drill holes in Tern Lake deposits, Antarctica, using liquid scintillation counting (LSC) and accelerator mass spectrometry (AMS). The results show that the lake deposits have been accumulating since the end of the last glacial epoch ca. 12,600 cal BP at the rate of 0.13-1.1 mm a-1. We discuss the validity of 14C ages of Antarctic lake deposits, with respect to the latitude effect of 14C productivity, the reservoir effect, the environment effect and the hard-water effect.This material was digitized as part of a cooperative project between Radiocarbon and the University of Arizona Libraries.The Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202

14C Dating of Terrestrial Moss in Tern Lake Deposits, Antarctica

From the 16th International Radiocarbon Conference held in Gronigen, Netherlands, June 16-20, 1997.Accurate radiocarbon ages were obtained from terrestrial moss from two drill holes in Tern Lake deposits, Antarctica, using liquid scintillation counting (LSC) and accelerator mass spectrometry (AMS). The results show that the lake deposits have been accumulating since the end of the last glacial epoch ca. 12,600 cal BP at the rate of 0.13-1.1 mm a-1. We discuss the validity of 14C ages of Antarctic lake deposits, with respect to the latitude effect of 14C productivity, the reservoir effect, the environment effect and the hard-water effect.This material was digitized as part of a cooperative project between Radiocarbon and the University of Arizona Libraries.The Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202

Investigation of the pressure distributions around quasi-rectangular shield tunnels in soft soils with a shallow overburden: A field study

The magnitudes and distributions of the pressures around a tunnel lining are the most significant variables in shield tunnel design, as they determine the safety of the lining structure and influence the investment cost of the tunnel project. The grouting process has a negligible effect on the pressures exerted on the shield tunnel segmental linings when the boring machine is drilling. However, improper grouting control might result in large bending moments, local damage of segments and leakage at joints, leading to a reduction of the linings' safety, durability and serviceability. On the other hand, more and more special-section shield tunnels are developed to solve the problems associated with infrastructure construction under complex environmental conditions. How-ever, previous studies on the pressure distribution around tunnel linings all focused on circular tunnels. Few research about the loads during construction on special-section shield tunnels was conducted. In this study, three in-situ monitoring tests for the total pressure distributions of shallow buried quasi-rectangular tunnels in soft soils were carried out, which is deemed to be the first field study for special-section shield tunnels. Different grouting situations were adopted and the temporal and spatial distributions of the lining pressures during and after the construction were obtained. When the lining segments are pushed out of the shield tail, the adverse pressure distributions caused by grout ejections were observed which are typical non-uniform and unsymmet-rical. The effect of different grouting situations attenuates quickly in the longitudinal direction within a range of 9 rings. Additionally, the influence of the following back-up equipment and transportation carriages on the pressures outside the linings were first observed and studied by means of these field tests. The outside pressures fluctuated in different stages with the coincident pace of construction activities and performed as a counterforce and to resist the inside loads, which was different from the active loads exerted on the lining when the segmental rings were pushed out. From the long-term perspective, the pressure distributions in different tests tend to stabilize at a similar state. The influence of the grouting process or other construction loads on the lining pressures needed about 50 days to be relieved. A comparison between the measured results and the theoretical long-term pressures was conducted and the applicability of the proposed load distributions in the design model for quasi-rectangular tunnels was demonstrated. Additionally, a pressure mode combining cosinusoidal pressures and theoretical long-term pressures is proposed to predict the grouting pressures when lining segments are pushed out of the shield