Cholesterol transport through lysosome-peroxisome membrane contacts.

Cholesterol is dynamically transported among organelles, which is essential for multiple cellular functions. However, the mechanism underlying intracellular cholesterol transport has remained largely unknown. We established an amphotericin B-based assay enabling a genome-wide shRNA screen for delayed LDL-cholesterol transport and identified 341 hits with particular enrichment of peroxisome genes, suggesting a previously unappreciated pathway for cholesterol transport. We show dynamic membrane contacts between peroxisome and lysosome, which are mediated by lysosomal Synaptotagmin VII binding to the lipid PI(4,5)P2 on peroxisomal membrane. LDL-cholesterol enhances such contacts, and cholesterol is transported from lysosome to peroxisome. Disruption of critical peroxisome genes leads to cholesterol accumulation in lysosome. Together, these findings reveal an unexpected role of peroxisome in intracellular cholesterol transport. We further demonstrate massive cholesterol accumulation in human patient cells and mouse model of peroxisomal disorders, suggesting a contribution of abnormal cholesterol accumulation to these diseases.

Neuroprotective effects of miRNA-326 knockout in neonatal hypoxic-ischemic brain damage mice via the δ-opioid receptor.

Hypoxic-ischemic brain damage (HIBD) in the perinatal period is an important cause of cerebral damage and long-term neurological sequelae, and can place much pressure on families and society. Our previous study demonstrated that miRNA-326 reduces neuronal apoptosis by up-regulating the δ-opioid receptor (DOR) under oxygen-glucose deprivation in vitro. In the present study, we aimed to explore the neuroprotective effects of the miRNA-326/DOR axis by inhibiting apoptosis in HIBD using neonatal miRNA-326 knockout mice. Neonatal C57BL/6 mice, neonatal miRNA-326 knockout mice, and neonatal miRNA-326 knockout mice intraperitoneally injected with the DOR inhibitor naltrindole were treated with hypoxic-ischemia (HI). Neurological deficit scores, magnetic resonance imaging, terminal deoxynucleotidyl transferase-mediated uridine 5'-triphosphate-biotin nick end labeling, and Caspase-3, Bax, and B-cell lymphoma 2 (Bcl-2) expression were evaluated on day 2 after HI. Neurobehavioral analyses were performed on days 2 and 28 after HI. Additionally, the Morris water maze test was conducted on days 28. Compared with HI-treated neonatal C57BL/6 mice, HI-treated neonatal miRNA-326 knockout mice had higher neurological deficit scores, smaller cerebral infarction areas, and improved motor function, reaction ability, and long-term spatial learning and memory. These effects were likely the result of inhibiting apoptosis; the DOR inhibitor reversed these neuroprotective effects. Our findings indicate that miRNA-326 knockout plays a neuroprotective effect in neonatal HIBD by inhibiting apoptosis via the target gene DOR.

Interferometric-scale full-field vibration measurement by a combination of digital image correlation and laser vibrometer.

Digital Image Correlation (DIC) is a crucial noncontact full-field optical measurement method used in various fields. However, in practical applications, DIC is affected by systematic and random noises, leading to experimental resolutions lower than theoretical ones. In this study, we proposed a laser Doppler vibrometer guided DIC to perform vibration measurements. 3D-DIC obtains a sequence of out of displacement field initially. A three-dimensional frequency domain collaborative filtering (3D-FDCF) method that utilizes Laser Doppler vibrometer (LDV) single-point data to assist in processing of the displacement field sequence pixel-wise is adopted. The 3D-FDCF method combines lowpass filtering in the spatial frequency domain with LDV-guided bandpass filtering in the temporal frequency domain. The effectiveness of the 3D-FDCF method is demonstrated through a comparison among DIC data, the filtered DIC data, and continuously scanning LDV data. The experiment results demonstrate the 3D-FDCF method's capability in measuring vibration amplitudes of several hundred nanometers with the size of a test sample of about 100 mm × 100 mm, supporting the statement of interferometric scale full-field vibration measurement by DIC with the guidance of the LDV data.

Copper-Catalyzed Aromatization-Driven Ring-Opening Amination and Oxygenation of Spiro Dihydroquinazolinones.

Mild and inexpensive copper-catalyzed aromatization-driven ring-opening amination and oxygenation of spiro dihydroquinazolinones are presented, respectively. These protocols provide facile and atom-economical access to the aminated and the carbonyl-containing quinazolin-4(3H)-ones in good yields with good functional group compatibility, which are difficult to obtain by conventional methods. Remarkably, a telescoped procedure involving the condensation and the ring-opening/functionalization for simple cycloalkanone was found to be accessible. Mechanistic studies suggest a radical pathway for this transformation.

Multi-Omics Study on Molecular Mechanisms of Single-Atom Fe-Doped Two-Dimensional Conjugated Phthalocyanine Framework for Photocatalytic Antibacterial Performance.

Currently, photocatalysis of the two-dimensional (2D) conjugated phthalocyanine framework with a single Fe atom (CPF-Fe) has shown efficient photocatalytic activities for the removal of harmful effluents and antibacterial activity. Their photocatalytic mechanisms are dependent on the redox reaction-which is led by the active species generated from the photocatalytic process. Nevertheless, the molecular mechanism of CPF-Fe antimicrobial activity has not been sufficiently explored. In this study, we successfully synthesized CPF-Fe with great broad-spectrum antibacterial properties under visible light and used it as an antibacterial agent. The molecular mechanism of CPF-Fe against Escherichia coli and Salmonella enteritidis was explored through multi-omics analyses (transcriptomics and metabolomics correlation analyses). The results showed that CPF-Fe not only led to the oxidative stress of bacteria by generating large amounts of h+ and ROS but also caused failure in the synthesis of bacterial cell wall components as well as an osmotic pressure imbalance by disrupting glycolysis, oxidative phosphorylation, and TCA cycle pathways. More surprisingly, CPF-Fe could disrupt the metabolism of amino acids and nucleic acids, as well as inhibit their energy metabolism, resulting in the death of bacterial cells. The research further revealed the antibacterial mechanism of CPF-Fe from a molecular perspective, providing a theoretical basis for the application of CPF-Fe photocatalytic antibacterial nanomaterials.

Weight progression and adherence to weight gain target in women with vs. without gestational diabetes: a retrospective cohort study.

BACKGROUND: Weight management has been an important component of the service in obstetric care offered to pregnant women. Current gestational weight gain recommendations were primarily for the general obstetric population, raising concern about the applicability to women with gestational diabetes mellitus (GDM). We aimed to assess the difference in weight progression and adherence to the recommended gestational weight gain targets between women with gestational diabetes mellitus (GDM) and women with normal glucose tolerance (NGT). METHODS: This was a hospital-based retrospective study of 56,616 pregnant women (9,430 GDM women and 47,186 NGT women) from Guangzhou between 2017 and 2021. The average change in weight progression was estimated based on serial weight measurements throughout pregnancy, using a mixed effects model with a random intercept to account for repeated measures of the same individual. RESULTS: Women with GDM gained less weight (12.07 [SD 5.20] kg) than women with NGT (14.04 [SD 5.04] kg) throughout pregnancy. Before OGTT, a small difference was observed in the average change in weight progression between the two groups (GDM, 0.44 kg/week vs. NGT, 0.45 kg/week, p < 0.001), however, this gap widened significantly after the test (0.34 vs. 0.50 kg/week, p < 0.001). GDM individuals were identified with an approximately 4-fold increased proportion of insufficient weight gain (41.1% vs. 10.4%) and a 2-fold decreased proportion of excessive weight gain (22.6% vs. 54.2%) compared to NGT individuals. These results were consistently observed across different BMI categories, including underweight (insufficient: 52.7% vs. 19.9%; excessive: 15.6% vs. 35.3%), normal weight (insufficient 38.2% vs. 7.4%; excessive: 22.2% vs. 57.3%), and overweight/obese (insufficient: 43.1% vs. 9.8%; excessive: 30.1% vs. 68.8%). CONCLUSION: Weight progression varied significantly between GDM and NGT individuals, resulting in a substantial difference in identifying insufficient and excessive weight gain between the two groups under current gestational weight gain guidelines.

A Bregman-Split-Based Compressive Sensing Method for Dynamic Harmonic Estimation.

In order to overcome the spectral interference of the conventional Fourier transform in the International Electrotechnical Commission framework, this paper introduces a Bregman-split-based compressive sensing (BSCS) method to estimate the Taylor-Fourier coefficients in a multi-frequency dynamic phasor model. Considering the DDC component estimation, this paper transforms the phasor problem into a compressive sensing model based on the regularity and sparsity of the dynamic harmonic signal distribution. It then derives an optimized hybrid regularization algorithm with the Bregman split method to reconstruct the dynamic phasor estimation. The accuracy of the model was verified by using the cross entropy to measure the distribution differences of values. Composite tests derived from the dynamic phasor test conditions were then used to verify the potentialities of the BSCS method. Simulation results show that the algorithm can alleviate the impact of dynamic signals on phasor estimation and significantly improve the estimation accuracy, which provides a theoretical basis for P-class phasor measurement units (PMUs).

[Cholesterol Metabolism and Tumor Immunity].

Cholesterol, an important lipid molecule of organisms, is involved in the formation of cell membrane structure, bile acid metabolism and steroid hormone synthesis, playing an important role in the regulation of cell structure and functions. In recent years, a large number of studies have shown that cholesterol metabolism is reprogrammed during tumor formation and development. In addition to directly affecting the biological behavior of tumor cells, cholesterol metabolic reprogramming also regulates the antitumor activity of immune cells in the tumor microenvironment. We reviewed herein the cholesterol metabolism reprogramming of and interactions among immune cells including myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), dendritic cells (DCs), and T cells in the tumor microenvironment. However, the relationship between cholesterol metabolism and tumor immunity in tumor microenvironment is complex and diversified. The differences and similarities of cholesterol metabolism reprogramming in tumor microenvironment in regulating immune cell activity and the specific regulatory mechanism are still unresolved issues. Targeted intervention of the cholesterol metabolism pathway of immune cells is expected to become a new strategy of cholesterol metabolism in tumor immunotherapy.

LDV-induced stroboscopic digital image correlation for high spatial resolution vibration measurement.

Vibration measurement, particularly mode shape measurement, is an important aspect of structural dynamic analysis since it can validate finite element or analytical vibration models. Scanning laser Doppler vibrometry (LDV) and high-speed digital image correlation have become dominant methods for experimental mode shape measurement. However, these methods have high equipment costs and several disadvantages regarding spatial or temporal performance. This paper proposes a laser Doppler vibrometer induced stroboscopic digital image correction for non-contact mode shape and operational deflection shape measurement. Our results verify that single-point LDV and normal rate cameras can be used obtain high spatial resolution mode shape and operational deflection shape. Measurement frequency range is much higher than the camera capturing rate. We also show that the proposed approach coincides well with time-averaged electronic speckle pattern interferometry.

Identifying rotational symmetry axes in Kikuchi patterns by reciprocal vectors.

Symmetry analysis of the Kikuchi pattern is helpful to determine the crystal structure, and can significantly reduce the screening range of phase identification, thereby improving the accuracy and reliability of phase identification in electron backscatter diffraction (EBSD). Accurately identifying the symmetry axis from the Kikuchi pattern is the primary task of symmetry analysis. In this study, a new method was proposed to identify symmetry axes in Kikuchi patterns with the aid of reciprocal vectors. Taking the Kikuchi patterns of single-crystal silicon as a typical example, a method for drawing reciprocal vectors after strict projection correction is introduced. The complex task of identifying the symmetry axis is transformed into an intuitive judgment of the geometric relationship between reciprocal vectors, thus greatly simplifying the process. This method successfully elucidated information on six Kikuchi poles in three single-crystal silicon Kikuchi patterns, including 3-fold axes, 4-fold axes and asymmetric axes. The method can also distinguish between a 3-fold axis and an analogous 3-fold axis despite their only slight differences.

Symmetry analysis of the Kikuchi pattern is helpful to determine the crystal structure, and can significantly reduce the screening range of phase identification, thereby improving the accuracy and reliability of phase identification in electron backscatter diffraction (EBSD). Accurately identifying the symmetry axis from the Kikuchi pattern is the primary task of symmetry analysis. In our study, a new method was proposed to identify symmetry axes in Kikuchi patterns with the aid of reciprocal vectors. Taking the Kikuchi patterns of single-crystal silicon as a typical example, a method for drawing reciprocal vectors after strict projection correction is introduced. The complex task of identifying the symmetry axis is transformed into an intuitive judgment of the geometric relationship between reciprocal vectors, thus greatly simplifying the process. This method successfully elucidated information on six Kikuchi poles in three single-crystal silicon Kikuchi patterns, including 3-fold axes, 4-fold axes and asymmetric axes. The method can also distinguish between a 3-fold axis and an analogous 3-fold axis despite their only slight differences. It is indicated that the reciprocal vectors after projection correction can reflect the symmetry information well, making the identification of the symmetry axis more intuitive, which is helpful for symmetry analysis of the Kikuchi pattern, and lays an important foundation for phase identification using crystal symmetry.

Local Kikuchi band detection in electron backscatter diffraction patterns for enhanced pattern indexing.

Partially missing bands in the preset region for Hough transform might strongly affect the accuracy of indexing Kikuchi patterns and reduce the quality of electron backscatter diffraction (EBSD) maps. This paper proposes a novel local band detection method for such kind of low-quality patterns. The approach involves rotating bands to vertical direction, detecting the local line segments through calculating the largest horizontal average grey gradient with a constant interval of 400 pixels in vertical direction, and applying Hough transform as well as weighted averaging to these line clusters to unify the edges of Kikuchi band. Therefore, even if only part of a Kikuchi band is visible, the entire band can also be accurately extracted. The average interplanar angle error obtained by the proposed method is approximately 29.0% less than those obtained by Hough transform-based technique. Moreover, the comparison of mean angular deviation (MAD) is also discussed. The average MAD of this method is about 38.5% lower than that of Hough transform-based technique. Consequently, the local Kikuchi band detection method is expected to be used for post-processing and re-indexing the EBSD low-quality patterns.

Method for acquiring accurate coordinates of the source point in electron backscatter diffraction.

An electron backscatter diffraction device is an important accessory for a scanning electron microscope and can provide crystal structure orientation and phase content data through analysis of electron backscatter diffraction patterns. The acquisition of these data depends on pattern indexing, including interplanar angle calculation and crystal plane indexation. The coordinates of the source point are key points for interplanar angle calculation, and they vary with the movement of the incident beam. In this study, we first combined the grey gradient calculation with screen moving method to achieve accurate positioning of source point and obtained coordinates of source point with sub-pixel precision. The errors of three coordinates were 0.07%, 0.06% and 0.04%, respectively. By using this coordinate of source point to conduct interplanar angle calculation the maximum error was 0.53°, which was a good proof of the accuracy of source point positioning. Then we established the relationship between source point coordinates variation and incident beam movement. Coordinates can be given out based on the displacement of beam directly. And to illustrate the accuracy, interplanar angle calculation was performed and the maximum error was 0.81°. This means that the relationship between variation of source point coordinates and beam movement is highly accurate.

Comparative study of B content and δ11 B in the enamel of isolated teeth from brothers in the same family.

RATIONALE: The quantity of boron (B) and its isotopic ratios in tooth can provide information on dietary habits and oral health of individuals. These metrics are gradually being used in stomatology, environmental science and geochemistry. METHODS: This study measured the B concentration and δ11 B in the enamel of isolated teeth from brothers in the same family living in high-B-exposure areas at different times using inductively coupled plasma mass spectrometry (ICP-MS) and multicollector ICP-MS. RESULTS: The results demonstrate that B content in tooth samples of two brothers is related to the time of shedding. The earlier the time of shedding, the lower is the B content in tooth. The B content increased from 20.5 µg/g of the central incisor (6-7 years old) of the younger brother to 50.4 µg/g of the second molar (10-12 years old). And B content for the elder brother increased from 28.7 to 58.3 µg/g at the same positions. In the same family, the diet and environmental input of B is basically similar, and the B exposure is basically the same every year. The annual growth rate of B for the younger brother in this experiment is about 4.98 µg/g per year and that for the elder brother is about 4.93 µg/g per year. The δ11 B of shed teeth at different times from the same person is basically similar, but different from person to person. The δ11 B of shed teeth from the elder brother varies from 15.5‰ to 17.9‰ and from the younger brother varies from 5.2‰ to 6.7‰. The δ11 B is quite different for the brothers in the same family who had the same food and environmental intake of B. CONCLUSIONS: The experimental data confirmed the relationship between the information of B (B content and δ11 B) in shed teeth and B exposure. They provided an experimental basis using modern human teeth to apply B-isotope paleo-environmental significance.

Silencing of a putative alanine aminotransferase (ALT) gene influences free amino acid composition in hemolymph and fecundity of the predatory bug, Cyrtorhinus lividipennis Reuter.

In Asian rice systems, Cyrtorhinus lividipennis Reuter is an important predator that preys on rice planthopper eggs and young nymphs, as a primary food source. Alanine aminotransferase (ALT) acts in many physiological and biochemical processes in insects. We cloned the full-length complementary DNA of C. lividipennis ClALT. Expression analysis showed higher expression in the fat body and midgut compared to other tissues. It is expressed in all C. lividipennis developmental stages and at least four organs. Silencing of ClALT by RNA interference significantly decreased the ClALT enzyme activity and ClALT expression compared to dsGFP-treated controls at 2 days after emergence (DAE). Silencing of ClALT influenced free hemolymph amino acid compositions, resulting in a reduction of Aspartic acid (Asp) and Alanine (Ala) proportions, and increased Cysteine (Cys) and Valine (Val) proportions in females at 2 DAE. dsClALT treatments led to decreased soluble total protein concentrations in ovary and fat body, and to lower reduced vitellogenin (Vg) expression, body weight, and the numbers of laid eggs. The double-stranded RNA viruse treatments also led to prolonged preoviposition periods and hindered ovarian development. Western blot analysis indicated that silencing ClALT also led to reduced fat body Vg protein abundance at 2 DAE. These data support our hypothesis that ClALT influences amino acid metabolism and fecundity in C. lividipennis.

A Fringe Phase Extraction Method Based on Neural Network.

In optical metrology, the output is usually in the form of a fringe pattern, from which a phase map can be generated and phase information can be converted into the desired parameters. This paper proposes an end-to-end method of fringe phase extraction based on the neural network. This method uses the U-net neural network to directly learn the correspondence between the gray level of a fringe pattern and the wrapped phase map, which is simpler than the exist deep learning methods. The results of simulation and experimental fringe patterns verify the accuracy and the robustness of this method. While it yields the same accuracy, the proposed method features easier operation and a simpler principle than the traditional phase-shifting method and has a faster speed than wavelet transform method.

A New Pattern Quality Assessment Criterion and Defocusing Degree Determination of Laser Speckle Correlation Method.

The laser speckle correlation method has found widespread application for obtaining information from vibrating objects. However, the resolution and accuracy of the laser speckle correlation method as they relate to the defocusing degree have not been analyzed sufficiently. Furthermore, the possible methods for speckle pattern quality assessment and enhancement have not been studied. In this study, the resolution and accuracy of the laser speckle correlation method are analyzed, and it is found that they are affected by the defocusing degree and speckle pattern quality, respectively. A new speckle pattern quality criterion combining the mean intensity gradient and frequency spectrum was proposed, called CMZ. The quality of the speckle pattern is higher when the CMZ is closer to zero. The proposed criterion was verified by simulated speckle patterns and real speckle patterns with different speckle sizes, densities, and gray contrasts. In the experimental setup stage, a suitable defocusing degree can be selected based on the resolution requirement and optimal speckle size, and other experimental parameters can be determined according to the CMZ criterion. Rotation and vibration experiments verified the effectiveness of the laser speckle correlation method and confirmed the reliability of the experiment preparation based on proposed CMZ criterion.

[A Review of the Lipid Metabolism Reprogramming in Tumor Associated Macrophages].

Tumor associated macrophages (TAMs) are one of the most common types of stromal cells in solid tumors. They are closely related to the immunosuppressive status of tumor microenvironment and potentiate the malignant progress of tumors. Studies have shown that metabolism in tumor associated macrophages has been reprogrammed and involved in the regulation of their own polarization and corresponding functions and phenotypes. Metabolic reprogramming refers to the alteration of key enzymes activity, substrate and its associated metabolites' concentration in a certain metabolic pathway, which accounts for the disorder of original metabolic states. In this paper, we mainly concentrated on the lipid metabolic reprogramming of TAMs, including triglycerides, fatty acids and their derivatives, cholesterol, phospholipids, and their regulations on tumor progression. However, the metabolism of tumor and tumor microenvironment cells is highly heterogeneous. It is worthy of further exploration on the similarities and differences of lipid metabolism reprogramming between stromal cells and tumor cells, and the mechanism of how reprogramming modulates cell activity. It will be a new strategy for immunotherapy of tumor with metabolic intervention to accurately target the lipid metabolism reprogramming of TAMs, so as to promote the polarization of TAMs to M1 like macrophages, when synthetically considering the diverse types of tumors and different stages of development.

[Contamination of zearalenone and its dietary exposure assessment in coix seed in Shanghai].

OBJECTIVE: To analyze the zearalenone(ZEN) level in coix seed, and assess the risk of dietary exposure of ZEN in coix seed in Shanghai. METHODS: The ZEN contents of 147 coix seed samples collected in Shanghai were determined. The consumption data of 730 adults in Shanghai was collected by questionnaire survey with random sampling method. Dietary intake of ZEN from coix seed in Shanghai was simulated by Monte Carlo simulation. RESULTS: The total detection rate of ZEN in coix seed was 69. 39 %(102/147), with the content range of <1. 0-9361 µg/kg and the average value of 327. 7 µg/kg. The average exposure level of populations to ZEN in coix seed was 0. 0216 µg/(kg·d), which was much lower than the tolerable daily intake(TDI). The high exposure level(P95) of populations to ZEN in coix seed was 0. 0609 µg/(kg·d), which accounted for about 24% of TDI. There were about 1. 1% people with the dietary exposure to ZEN exceeding TDI on the basis of the ZEN contents in coix seed and consumption data of coix seed in Shanghai. CONCLUSION: The health risk of ZEN exposure of coix seed in Shanghai population is lower when taking coix seed regularly, and there are potential health risks when taking coix seed highly contaminated with ZEN at a higher dose for a long time.

[A Comparative Study of Intraoperative Application of Fluorescein and Indocyanine Green Videoangiography in Intracranial Aneurysm Clipping Surgery].

OBJECTIVE: To compare the application of fluorescein videoangiography (FL-VA) and indocyanine green videoangiography (ICG-VA) in intracranial aneurysm surgery. METHODS: A total of 65 patients who underwent aneurysm clipping in our hospital from January 2019 to January 2020 were included in the study. FL-VA and ICG-VA were used during the surgery to determine whether the aneurysm is completely clipped and the artery bearing the aneurysm and the perforating artery around the aneurysm are unobstructed. RESULTS: All 65 patients underwent both FL-VA and ICG-VA intraoperatively after aneurysm clipping. FL-VA was applied first. In 30 cases, FL-VA and ICG-VA provided the same results. In 10 cases, FL-VA performed obviously better over ICG-VA in visualizing small perforating arteries (2 cases of internal carotid artery-posterior communicating artery aneurysms and 3 cases of anterior communicating artery aneurysm) and evaluating whether the aneurysm was completely clipped (3 cases of middle cerebral artery aneurysm, 1 case of internal carotid artery-posterior communicating artery aneurysms and 1 case of distal anterior cerebral artery aneurysm). In the remaining 25 cases, ICG-VA was repeatedly applied in a short period of time due to quick clearance of indocyanine green from the blood vessels, but this couldn't be done with FL-VA. CONCLUSIONS: Compared with ICG-VA, FL-VA can provide better visualization of perforating artery, and can determine whether the aneurysm was completely clipped more accurately. However FL-VA couldn't be repeatedly applied during a short period of time.