111 research outputs found
Purification and characterization of farnesyl diphosphate/geranylgeranyl diphosphate synthase
Journal ArticleFarnesyl diphosphate (FPP)/geranylgeranyl diphosphate (GGPP) synthase, a bifunctional enzyme that synthesizes C15 and C2o isoprenoid diphosphates from isopentenyl diphosphate and dimethylallyl diphosphate, was purified to homogeneity from the archae-bacterium Methanobacterium thermoautotrophicum. The only activities detected from synthesis of FPP and GGPP copurified through (NH4)2S04 precipitation and four chromatographic steps. The pure enzyme was a 79-kDa homodimer that catalyzed the sequential addition of isopentenyl diphosphate to dimethylallyl diphosphate, geranyl diphosphate, and FPP by a non-processive mechanism which allowed substantial amounts of FPP to accumulate during turnover, creating a pool for further elongation to GGPP or for synthesis of squalene. The bifunctional enzyme required Mg2+ or Mn2+ and was optimally active at 65 °C. Catalysis of chain elongation in M. thermoautotrophicum differs from related reactions in eubacteria and eukaryotes, where distinct FPP synthases and GGPP synthases are found
Oil Displacement Efficiency and Performance Evaluation of Composite Ion Profile Control Agents Prepared with Oilfield Sewage
According to the demand of development in Daqing oil field, in order to reduce sewage discharge and save clean water, most of the polymer injection stations have switched to polymer solution diluted by sewage. Considering the present development trend of the oil field and requirement in terms of cost control, we should further deepen the research of formulas for all kinds of chemical sewage. Performance evaluating experiments on the long-term stability, the anti-shear property, the compatibility with initial rock debris and alkali ternary combination system of profile control agents, as well as the test for the efficiency of core displacement physical simulation of profile control and oil displacement evaluation are carried in this paper, which are intended for the composite ion profile control system that are prepared with oilfield sewage. In this paper, the long-term stable composite ion profile control agents formular prepared with oilfield sewage have been determined; the profile control effect of composite ion profile control agents prepared with sewage for cores with different permeability have been presented, and the rules of composite ion profile control agents prepared with sewage on oil displacement effect at different injection time and injection rate have been studied.Research shows that the long-term heat stability, anti-shear property, compatibility with initial rock debris and alkali ternary combination system of composite ion profile control agents prepared with sewage are well, as well as the core plugging effect and anti-corrosion performance. Oil displacement results are obviously different when profile control agents are injected at different time. Injecting profile control agents before polymer flooding works best, medium term secondly, and late stage thirdly. At the same time, the enhanced recovery rate increases with increased profile control agents injection. While the increase of enhanced oil recovery rate becomes slower when the profile control agents injection reach 0.1 PV. After profile control measures are taken, the average injection pressure and starting pressure has risen respectively by 2.7 Mpa and 2.6 Mpa; the water absorbing capacity of high permeable formation has been under control; the water absorbing capacity of low permeable formation has been strengthened; the absorbing water thickness of all wells have been increased; the breakthrough of flooded fluid in certain direction have been solved, which leads to more even polymer forward.Key words: Oil displacement effect evaluation; Performance evaluation; Composite ion profile control agents; Oil produced water preparing polymer
mmBody Benchmark: 3D Body Reconstruction Dataset and Analysis for Millimeter Wave Radar
Millimeter Wave (mmWave) Radar is gaining popularity as it can work in
adverse environments like smoke, rain, snow, poor lighting, etc. Prior work has
explored the possibility of reconstructing 3D skeletons or meshes from the
noisy and sparse mmWave Radar signals. However, it is unclear how accurately we
can reconstruct the 3D body from the mmWave signals across scenes and how it
performs compared with cameras, which are important aspects needed to be
considered when either using mmWave radars alone or combining them with
cameras. To answer these questions, an automatic 3D body annotation system is
first designed and built up with multiple sensors to collect a large-scale
dataset. The dataset consists of synchronized and calibrated mmWave radar point
clouds and RGB(D) images in different scenes and skeleton/mesh annotations for
humans in the scenes. With this dataset, we train state-of-the-art methods with
inputs from different sensors and test them in various scenarios. The results
demonstrate that 1) despite the noise and sparsity of the generated point
clouds, the mmWave radar can achieve better reconstruction accuracy than the
RGB camera but worse than the depth camera; 2) the reconstruction from the
mmWave radar is affected by adverse weather conditions moderately while the
RGB(D) camera is severely affected. Further, analysis of the dataset and the
results shadow insights on improving the reconstruction from the mmWave radar
and the combination of signals from different sensors.Comment: ACM Multimedia 2022, Project Page:
https://chen3110.github.io/mmbody/index.htm
ImmFusion: Robust mmWave-RGB Fusion for 3D Human Body Reconstruction in All Weather Conditions
3D human reconstruction from RGB images achieves decent results in good
weather conditions but degrades dramatically in rough weather. Complementary,
mmWave radars have been employed to reconstruct 3D human joints and meshes in
rough weather. However, combining RGB and mmWave signals for robust all-weather
3D human reconstruction is still an open challenge, given the sparse nature of
mmWave and the vulnerability of RGB images. In this paper, we present
ImmFusion, the first mmWave-RGB fusion solution to reconstruct 3D human bodies
in all weather conditions robustly. Specifically, our ImmFusion consists of
image and point backbones for token feature extraction and a Transformer module
for token fusion. The image and point backbones refine global and local
features from original data, and the Fusion Transformer Module aims for
effective information fusion of two modalities by dynamically selecting
informative tokens. Extensive experiments on a large-scale dataset, mmBody,
captured in various environments demonstrate that ImmFusion can efficiently
utilize the information of two modalities to achieve a robust 3D human body
reconstruction in all weather conditions. In addition, our method's accuracy is
significantly superior to that of state-of-the-art Transformer-based
LiDAR-camera fusion methods
Irisin attenuates pyroptosis in high glucose-induced pancreatic beta cells via the miR-133a-3p/FOXO1 axis
Introduction: Irisin is closely related to type 2 diabetes mellitus (T2DM) and other metabolic diseases. It can improve the homeostasis of T2DM. MiR-133a-3p is decreased in the peripheral blood of patients with T2DM. Forkhead box protein O1 (FOXO1) is widely expressed in beta-cells and affects the occurrence of diabetes through transcriptional regulation and signalling pathway regulation.
Material and methods: The miR-133a-3p inhibitor was constructed to verify the effect of irisin on pyroptosis through miR-133a-3p. Next, we predicted the presence of targeted binding sequences between FOXO1 and miR-133a-3p by bioinformatics software, which was then confirmed with a double fluorescence assay. Finally, the FOXO1 overexpression vector was used to further verify the effect of irisin through the miR-133a-3p/FOXO1 axis.
Results: We first observed that irisin inhibited the protein levels of N-terminal gasdermin D (GSDMD-N) and cleaved caspase-1 and the secretion of interleukins (IL): IL-1beta and IL-18 in Min6 cells treated with high glucoes (HG). Irisin inhibited pyroptosis of Min6 cells treated with HG by reinforcing miR-133a-3p. Then, FOXO1 was validated to be the target gene of miR-133a. Both miR-133a-3p inhibitor and overexpression of FOXO1 restrained the force of irisin on pyroptosis in HG-induced Min6 cells.
Conclusion: We explored the protective effect of irisin on HG-induced pyroptosis of islet b-cells in vitro and explained its mechanism of inhibiting pyroptosis through the miR-133a-3p/FOXO1 axis, to provide a theoretical basis for finding new molecular targets to delay beta-cell failure and the treatment of T2DM
Integration of aggregation-induced emission and delayed fluorescence into electronic donor–acceptor conjugates
A series of luminogens comprised electron donors and acceptors are
found to possess two types of interesting photophysical processes of
aggregation-induced emission (AIE) and delayed fluorescence. According
to theory calculation, restriction of intramolecular motions accounts
for their AIE characteristics. Moreover, a separated distribution of the
HOMOs and the LUMOs of these luminogens leads to small DEST
values and therefore delayed fluorescence
The Aroma Composition of Baby Ginger Paocai
The purpose of this study was to analyze the volatile compounds in baby ginger paocai and the fresh baby ginger and identify the key aroma components that contribute to the flavor of baby ginger paocai. A total of 86 volatile compounds from the two baby ginger samples were quantified; these compounds were extracted by headspace solid-phase microextraction (HS-SPME) and analyzed by gas chromatography–mass spectrometry (GC-MS). The aroma composition of baby ginger paocai was different from that of fresh baby ginger. Baby ginger paocai was characterized by the presence of aroma-active compounds which varied in concentration from 0.03 to 28.14%. Geranyl acetate was the aroma component with the highest relative content in baby ginger paocai. β-myrcene, eucalyptol, trans-β-ocimene, Z-ocimene, linalool, decanal, cis-citral, geraniol, geranyl acetate, curcumene, and β-bisabolene contributed to the overall aroma of the product of baby ginger paocai which had gone through a moderate fermentation process
Exploring the differential stages of the pigment metabolism by pre-harvest bagging and post-harvest ethylene de-greening of Eureka lemon peel
Pre-harvest bagging or post-harvest ethylene treatments on lemons are commonly applied to change the surface color from green to favorable yellow. In this study, the differential mechanisms of the pigment metabolism by the two treatments were investigated by pigments contents and related genetic expression. The results showed that both treatments reduced the number of chloroplasts and the content of chlorophyll. The differential expression of PSY1 and PSY2 were observed, causing the different accumulation of the main carotenoid phytoene content. The differential expression of NYC resulted in altered contents of chlorophyll a and chlorophyll b, and further led to the difference in a* value. More interestingly, the degradation of chlorophyll uncovered the color of carotenoids, leading to the color changed from green to yellow
Aggregation-Induced Emission (AIE), Life and Health
Light has profoundly impacted modern medicine and healthcare, with numerous luminescent agents and imaging techniques currently being used to assess health and treat diseases. As an emerging concept in luminescence, aggregation-induced emission (AIE) has shown great potential in biological applications due to its advantages in terms of brightness, biocompatibility, photostability, and positive correlation with concentration. This review provides a comprehensive summary of AIE luminogens applied in imaging of biological structure and dynamic physiological processes, disease diagnosis and treatment, and detection and monitoring of specific analytes, followed by representative works. Discussions on critical issues and perspectives on future directions are also included. This review aims to stimulate the interest of researchers from different fields, including chemistry, biology, materials science, medicine, etc., thus promoting the development of AIE in the fields of life and health
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