GPCR activation and GRK2 assembly by a biased intracellular agonist.

Phosphorylation of G-protein-coupled receptors (GPCRs) by GPCR kinases (GRKs) desensitizes G-protein signalling and promotes arrestin signalling, which is also modulated by biased ligands1-6. The molecular assembly of GRKs on GPCRs and the basis of GRK-mediated biased signalling remain largely unknown owing to the weak GPCR-GRK interactions. Here we report the complex structure of neurotensin receptor 1 (NTSR1) bound to GRK2, Gαq and the arrestin-biased ligand SBI-5537. The density map reveals the arrangement of the intact GRK2 with the receptor, with the N-terminal helix of GRK2 docking into the open cytoplasmic pocket formed by the outward movement of the receptor transmembrane helix 6, analogous to the binding of the G protein to the receptor. SBI-553 binds at the interface between GRK2 and NTSR1 to enhance GRK2 binding. The binding mode of SBI-553 is compatible with arrestin binding but clashes with the binding of Gαq protein, thus providing a mechanism for its arrestin-biased signalling capability. In sum, our structure provides a rational model for understanding the details of GPCR-GRK interactions and GRK2-mediated biased signalling.

How do sleepwear and bedding fibre types affect sleep quality: A systematic review.

Sleepwear and bedding materials can affect sleep quality by influencing the skin and body temperature and thermal comfort. This review systematically evaluates the impact of sleepwear or bedding of different fibre types on sleep quality. A systematic search was conducted in six data bases plus Google Scholar and manual searches. Original articles that compared human sleep quality between at least two fibre types of bedding or sleepwear were included, resulting in nine eligible articles included in the review. The fibre types included cotton, polyester, wool, and blended materials for sleepwear; cotton, duck down, goose down, polyester and wool for duvet; and linen and a combination of cotton and polyester for bedding. The interplay between fibre materials and sleep quality is complex. Blended sleepwear demonstrated potential benefits for specific populations. Wool sleepwear showed benefits for sleep onset in adults (cool conditions) and in older adults (warm conditions). Linen bedsheets improved sleep quality under warm conditions in young adults. Goose down-filled duvets increased slow-wave sleep under cool conditions in young adults. However, a systematic comparison of fibre types is challenging due to the diverse nature of the studies evaluating sleep quality. Further research employing standardised methodologies with standard fibre samples in different populations and in different temperature conditions is imperative to elucidate comprehensively the effects of fibre choices on sleep quality. Despite the limitations and heterogeneity of the included studies, this analysis offers valuable insights for individuals seeking to optimise their sleep experiences and for manufacturers developing sleep-related products.

On-Tissue Chemical Oxidation Followed by Derivatization for Mass Spectrometry Imaging Enables Visualization of Primary and Secondary Hydroxyl-Containing Metabolites in Biological Tissues.

On-tissue chemical derivatization combined with mass spectrometry imaging (MSI) can effectively visualize low-abundance and poorly ionizable molecules in biological tissues. Owing to the lack of an effective chemical reaction environment on the tissue surface, the development of direct one-step derivatization reactions is challenging. Herein, we present a two-step reaction involving on-tissue chemical oxidation followed by derivatization combined with airflow-assisted desorption electrospray ionization-MSI, enabling the visualization of primary and secondary hydroxyl-containing metabolites (PSHMs) within the tissue sections. This method indirectly achieved on-tissue derivatization by combining two reactions. Hydroxyl was converted to carbonyl using chemical oxidants, and subsequently, carbonyl was derived using Girard's P reagent. Using this methodology, 169 PSHMs, including hydroxy fatty acids (OH-FAs), fatty alcohols (FOHs), and sterol lipids, were detected and imaged in the tissues of rat brain, kidney, and liver. Moreover, we found that the abundant PSHMs, fatty aldehydes, and oxo fatty acids were significantly dysregulated in the liver and kidney tissues of type 2 diabetic rats; in particular, OH-FAs and FOHs were remarkably up-regulated in the diabetic rat liver tissues. The aberrations of these oxidative metabolites provide insights into the understanding of the molecular pathological mechanism of diabetes. This study demonstrates a novel, two-step reaction strategy for on-tissue derivatization with the analysis of previously inaccessible molecules using MSI.

Database-Driven Spatially Resolved Lipidomics Highlights Heterogeneous Metabolic Alterations in Type 2 Diabetic Mice.

Spatially resolved lipidomics is pivotal for detecting and interpreting lipidomes within spatial contexts using the mass spectrometry imaging (MSI) technique. However, comprehensive and efficient lipid identification in MSI remains challenging. Herein, we introduce a high-coverage, database-driven approach combined with air-flow-assisted desorption electrospray ionization (AFADESI)-MSI to generate spatial lipid profiles across whole-body mice. Using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS), we identified 2868 unique lipids in the serum and various organs of mice. Subsequently, we systematically evaluated the distinct ionization properties of the lipids between LC-MS and MSI and created a detailed MSI database containing 14 123 ions. This method enabled the visualization of aberrant fatty acid and phospholipid metabolism across organs in a diabetic mouse model. As a powerful extension incorporated into the MSIannotator tool, our strategy facilitates the rapid and accurate annotation of lipids, providing new research avenues for probing spatially resolved heterogeneous metabolic changes in response to diseases.

Diamond Nanomechanical Resonators Protected by a Phononic Band Gap.

We report the design, fabrication, and characterization of diamond cantilevers attached to a phononic square lattice. We show that the robust protection of mechanical modes by phononic band gaps leads to a three-orders-of-magnitude increase in mechanical Q-factors, with the Q-factors exceeding 106 at frequencies as high as 100 MHz. Temperature-dependent studies indicate that the Q-factors obtained at a few Kelvin are still limited by the materials loss. The high-Q diamond nanomechanical resonators provide a promising hybrid quantum system for spin-mechanics studies.

A Novel Mechanism for SIRT1 Activators That Does Not Rely on the Chemical Moiety Immediately C-Terminal to the Acetyl-Lysine of the Substrate.

SIRT1, an NAD+-dependent deacetylase, catalyzes the deacetylation of proteins coupled with the breakdown of NAD+ into nicotinamide and 2'-O-acetyl-ADP-ribose (OAADPr). Selective SIRT1 activators have potential clinical applications in atherosclerosis, acute renal injury, and Alzheimer's disease. Here, we found that the activity of the potent SIRT1 activator CWR is independent of the acetylated substrate. It adopts a novel mechanism to promote SIRT1 activity by covalently bonding to the anomeric C1' carbon of the ribose ring in OAADPr. In addition, CWR is highly selective for SIRT1, with no effect on SIRT2, SIRT3, SIRT5, or SIRT6. The longer distance between the anomeric C1' carbon of the ribose ring in OAADPr and Arg274 of SIRT1 (a conserved residue among sirtuins) than that between the anomeric C1' carbon in OAADPr and the Arg of SIRT2, SIRT3, SIRT5, and SIRT6, should be responsible for the high selectivity of CWR for SIRT1. This was confirmed by site-directed mutagenesis of SIRT3. Consistent with the in vitro assays, the activator also reduced the acetylation levels of p53 in a concentration-dependent manner via SIRT1 in cells. Our study provides a new perspective for designing SIRT1 activators that does not rely on the chemical moiety immediately C-terminal to the acetyl-lysine of the substrate.

[Effects of Xiangqin Jiere Granules on lipid metabolism and chronic inflammation in different obesity model mice].

This paper aims to study the effect of Xiangqin Jiere Granules(XQ) on lipid metabolism and chronic inflammation in different obesity model mice. The monosodium glutamate(MSG) obese mouse model was established by subcutaneous injection of MSG in newborn mice, and the high fat diet(HFD) obese mouse model was established by feeding adult mice with HFD. The normal mice were assigned into the control group; the MSG obese mice were assigned into MSG model group, XQ4.5 group(Xiangqin Jiere Granu-les, 4.5 g·kg~(-1)), XQ22.5 group(Xiangqin Jiere Granules, 22.5 g·kg~(-1)); the HFD obese mice were assigned into HFD model group, XQ4.5 group, and XQ22.5 group. The mice were intragastrically administrated with saline or XQ for 5 weeks. After that, the body weight, visceral fat mass, liver and thymus weight, and the organ indexes in each group were measured. The levels of triglyceride(TG), total cholesterol(TC), and low-density lipoprotein cholesterol(LDL-c) in serum and liver tissue were detected by the kits. The mRNA expression levels of acetyl CoA carboxylase 1(ACC1), fatty acid synthetase(FAS), diacylgycerol acyltransferase 1(DGAT1) and hepatic lipase(HTGL) involved in lipid metabolism in mouse liver tissue were detected by quantitative real-time PCR(qPCR). The protein levels of tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6) in serum were detected by ELISA, and the mRNA levels of TNF-α and IL-6 in liver tissue were detected by qPCR. Compared with the control group, MSG and HFD mice showed increased body weight, abdominal circumference, Lee index and visceral fat mass as well as elevated levels of TG, TC, and LDL-c in serum. The model mice had up-regulated gene levels of ACC1, FAS and DGAT1 while down-regulated gene level of HTGL in the liver. Furthermore, the mRNA and protein levels of IL-6 increased in the model mice. Compared with the model mice, XQ treatment decreased the body weight, abdominal circumference, Lee index, and visceral fat mass, lowered the levels of TG, TC, and LDL-c in se-rum, down-regulated the gene levels of ACC1, FAS, and DGAT1 in liver tissue, up-regulated the gene level of HTGL, and down-regulated the mRNA and protein levels of IL-6. To sum up, XQ has good therapeutic effect on different obesity model mice. It can improve lipid metabolism and reduce fat accumulation in obese mice by regulating the enzymes involved in lipid metabolism, and alleviate obesity-related chronic low-grade inflammation.

Distinct mRNA and long non-coding RNA expression profiles of decidual natural killer cells in patients with early missed abortion.

Early non-chromosome-related missed abortion (MA) is commonly associated with an altered immunological environment during pregnancy. Human decidual natural killer (dNK) cells, the most abundant lymphocyte population within the first-trimester maternal-fetal interface, are vital maternal regulators of immune tolerance mediating successful embryo implantation and placentation. Previous studies have shown that dNK cells may play a role in MA. However, the gene expression status and specific altered manifestations of dNK cells in patients with early MA remain largely unknown. Here, we show that MA dNK cells have distinct mRNA and lncRNA expression profiles through RNA sequencing, with a total of 276 mRNAs and 67 lncRNAs being differentially expressed compared with controls. Protein-protein interaction analysis of differentially expressed mRNAs was performed to identify hub genes and key modules. An lncRNA-mRNA regulatory network characterized by the small-world property was constructed to reveal the regulation of mRNA transcription by differential hub lncRNAs. Functional annotation of differentially expressed mRNAs and lncRNAs was performed to disclose their potential roles in MA pathogenesis. Our data highlight several enriched biological processes (immune response, inflammatory response, cell adhesion, and extracellular matrix [ECM] organization) and signaling pathways (cytokine-cytokine receptor interaction, ECM-receptor interaction, Toll-like receptor signaling pathway, and phosphatidylinositol signaling system) that may influence MA. This study is the first to demonstrate the involvement of altered mRNA and lncRNA expression profiles in the dNK cell pathogenesis of early MA, facilitating a better understanding of the underlying molecular mechanisms and the development of novel MA therapeutic strategies targeting key mRNAs and lncRNAs.

The impaired myocardial ischemic tolerance in adult offspring of diabetic pregnancy is restored by maternal melatonin treatment.

Diabetic pregnancy, with ever increasing prevalence, adversely affects embryogenesis and increases vasculometabolic disorder risks in adult offspring. However, it remains poorly understood whether maternal diabetes increases the offspring's susceptibility to heart injuries in adulthood. In this study, we observed that cardiac function and structure were comparable between adult offspring born to diabetic mice and their counterparts born to nondiabetic mice at baseline. However, in response to myocardial ischemia/reperfusion (MIR), diabetic mother offspring exhibited augmented infarct size, cardiac dysfunction, and myocardial apoptosis compared with control, in association with exaggerated activation of mitochondria- and endoplasmic reticulum (ER) stress-mediated apoptosis pathways and oxidative stress. Molecular analysis showed that the impaired myocardial ischemic tolerance in diabetic mother offspring was mainly attributable to blunted cardiac insulin receptor substrate (IRS)-1/Akt signaling. Furthermore, the effect of maternal melatonin administration on offspring's response to MIR was determined, and the results indicated that melatonin treatment in diabetic dams during pregnancy significantly improved the tolerance to MIR injury in their offspring, via restoring cardiac IRS-1/Akt signaling. Taken together, these data suggest that maternal diabetes predisposes offspring to augmented MIR injury in adulthood, and maternal melatonin supplementation during diabetic pregnancy may hold promise for improving myocardial ischemic tolerance in the offspring.

On-tissue chemical derivatization-enhanced spatially resolved lipidomics reveals abnormal metabolism in type 2 diabetic rat brain.

Neurologic disorders are often accompanied by alterations in lipids and oxylipins in the brain. However, the complexity of the lipidome in the brain and its changes during brain damage caused by diabetes remain poorly understood. Herein, we developed an enhanced spatially resolved lipidomics approach with the assistance of on-tissue chemical derivatization to study lipid metabolism in the rat brain. This method enabled the spatially resolved analysis of 560 lipids and oxylipins in 19 brain microregions in coronal and sagittal sections and remarkably improved the coverage of lipidome detection. We applied this method to lipidomic studies of the diabetic rat brain and found that lipid dysregulation followed a microregion-specific pattern. Carnitines and glycerolipids were mainly elevated in the corpus callosum (midbrain) and pineal gland regions, respectively. In addition, most oxylipins, including fatty aldehydes and oxo fatty acids, were significantly upregulated in nine brain microregions. We produced a spatially resolved analysis of lipids and oxylipins, providing a novel analytical tool for brain metabolism research.

Mechanism and functional verification of genes by virulence factors of P. gingivalis in ferroptosis.

OBJECTIVE: Porphyromonas gingivalis (P. gingivalis) is a key etiological agent in periodontitis and functions as a facultative intracellular microorganism and involves many virulence factors. These virulence factors participate in multiple intracellular processes, like ferroptosis, the mechanistic underpinnings remain to be elucidated. Aim of this study was to investigate the effects of virulence factors on the host cells. DESIGN: Human umbilical vein endothelial cells (HUVECs) were treated with 4% paraformaldehyde-fixed P. gingivalis, and subsequent alterations in gene expression were profiled via RNA-seq. Further, the molecules associated with ferroptosis were quantitatively analyzed using qRT-PCR and Western blot. RESULTS: A total of 1125 differentially expressed genes (DEGs) were identified, encompassing 225 upregulated and 900 downregulated. Ferroptosis was conspicuously represented in the kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis, with notable upregulation of Heme oxygenase 1 (HMOX1), Ferritin light chain (FTL), and Solute carrier family 3 member 2 (SLC3A2) and downregulation of Scavenger receptor class A member 5 (SCARA5) and glutaminase (GLS). Random selection of DEGs for validation through qRT-PCR corroborated the RNA-Seq data (R2 = 0.93). Kelch like ECH associated protein 1 (Keap1) protein expression decreased after 4 and 8 h, while NFE2 like bZIP transcription factor 2 (Nrf2) and HMOX1 were elevated, with significant nuclear translocation of Nrf2. CONCLUSIONS: The virulence factors of P. gingivalis may potentially instigating ferroptosis through activation of the Keap1-Nrf2-HMOX1 signaling cascade, in conjunction with modulating the expression of other ferroptosis-associated elements. Further research is necessary to achieve a thorough comprehension of these complex molecular interactions.

Structural insights into ligand recognition, selectivity, and activation of bombesin receptor subtype-3.

Bombesin receptor subtype-3 (BRS3) is an important orphan G protein-coupled receptor that regulates energy homeostasis and insulin secretion. As a member of the bombesin receptor (BnR) family, the lack of known endogenous ligands and high-resolution structure has hindered the understanding of BRS3 signaling and function. We present two cryogenic electron microscopy (cryo-EM) structures of BRS3 in complex with the heterotrimeric Gq protein in its active states: one bound to the pan-BnR agonist BA1 and the other bound to the synthetic BRS3-specific agonist MK-5046. These structures reveal the architecture of the orthosteric ligand pocket underpinning molecular recognition and provide insights into the structural basis for BRS3's selectivity and low affinity for bombesin peptides. Examination of conserved micro-switches suggests a shared activation mechanism among BnRs. Our findings shed light on BRS3's ligand selectivity and signaling mechanisms, paving the way for exploring its therapeutic potential for diabetes, obesity, and related metabolic disorders.

Is tumor necrosis factor-α monoclonal therapy with proactive therapeutic drug monitoring optimized for inflammatory bowel disease? Network meta-analysis.

BACKGROUND: The efficacy and safety of anti-tumor necrosis factor-α (TNF-α) monoclonal antibody therapy [adalimumab (ADA) and infliximab (IFX)] with therapeutic drug monitoring (TDM), which has been proposed for inflammatory bowel disease (IBD) patients, are still controversial. AIM: To determine the efficacy and safety of anti-TNF-α monoclonal antibody therapy with proactive TDM in patients with IBD and to determine which subtype of IBD patients is most suitable for proactive TDM interventions. METHODS: As of July 2023, we searched for randomized controlled trials (RCTs) and observational studies in PubMed, Embase, and the Cochrane Library to compare anti-TNF-α monoclonal antibody therapy with proactive TDM with therapy with reactive TDM or empiric therapy. Pairwise and network meta-analyses were used to determine the IBD patient subtype that achieved clinical remission and to determine the need for surgery. RESULTS: This systematic review and meta-analysis yielded 13 studies after exclusion, and the baseline indicators were balanced. We found a significant increase in the number of patients who achieved clinical remission in the ADA [odds ratio (OR) = 1.416, 95% confidence interval (CI): 1.196-1.676] and RCT (OR = 1.393, 95%CI: 1.182-1.641) subgroups and a significant decrease in the number of patients who needed surgery in the proactive vs reactive (OR = 0.237, 95%CI: 0.101-0.558) and IFX + ADA (OR = 0.137, 95%CI: 0.032-0.588) subgroups, and the overall risk of adverse events was reduced (OR = 0.579, 95%CI: 0.391-0.858) according to the pairwise meta-analysis. Moreover, the network meta-analysis results suggested that patients with IBD treated with ADA (OR = 1.39, 95%CI: 1.19-1.63) were more likely to undergo TDM, especially in comparison with patients with reactive TDM (OR = 1.38, 95%CI: 1.07-1.77). CONCLUSION: Proactive TDM is more suitable for IBD patients treated with ADA and has obvious advantages over reactive TDM. We recommend proactive TDM in IBD patients who are treated with ADA.

Equally Efficient Perovskite Solar Cells and Modules Fabricated via N-Ethyl-2-Pyrrolidone Optimized Vacuum-Flash.

Efficiency reduction in perovskite solar cells (PSCs) during the magnification procedure significantly hampers commercialization. Vacuum-flash (VF) has emerged as a promising method to fabricate PSCs with consistent efficiency across scales. However, the slower solvent removal rate of VF compared to the anti-solvent method leads to perovskite films with buried defects. Thus, this work employs low-toxic Lewis base ligand solvent N-ethyl-2-pyrrolidone (NEP) to improve the nucleation process of perovskite films. NEP, with a mechanism similar to that of N-methyl-2-pyrrolidone in FA-based perovskite formation, enhances the solvent removal speed owing to its lower coordination ability. Based on this strategy, p-i-n PSCs with an optimized interface attain a power conversion efficiency (PCE) of 24.19% on an area of 0.08 cm2. The same nucleation process enables perovskite solar modules (PSMs) to achieve a certified PCE of 23.28% on an aperture area of 22.96 cm2, with a high geometric fill factor of 97%, ensuring nearly identical active area PCE (24%) in PSMs as in PSCs. This strategy highlights the potential of NEP as a ligand solvent choice for the commercialization of PSCs.

The first structure of human Golm1 coiled coil domain reveals an unexpected tetramer and highlights its structural diversity.

Golgi membrane protein 1 (Golm1), a transmembrane protein with diverse subcellular localizations, has garnered significant attention in recent years due to its strong association with the development and progression of liver diseases and numerous cancers. Interestingly, although Golm1 is a membrane protein, the C-terminal of Golm1, which contains a coiled coil domain and a flexible acid region, can also be detected in the plasma of patients with various liver diseases. Notably, the coiled coil domain of serum Golm1 is postulated to play a pivotal role in physiological and pathological functions. However, little is currently known about the structure of this coiled coil domain and the full-length protein, which may limit our understanding of Golm1. Therefore, this study aims to address this gap in knowledge and reports the first crystal structure of the coiled coil domain of Golm1 at a resolution of 2.28 Å. Meanwhile, we have also confirmed that the Golm1 coiled coil domain in solution can form tetramer. Our results reveal that Golm1 can form a novel tetrameric structure that differs from the previous reported dimeric structure Golm1 could assemble, which may provide novel insights into the diversity of physiological functions and pathological roles.

Discovery of ZJCK-6-46: A Potent, Selective, and Orally Available Dual-Specificity Tyrosine Phosphorylation-Regulated Kinase 1A Inhibitor for the Treatment of Alzheimer's Disease.

Targeting dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) has been verified to regulate the progression of tau pathology as a promising treatment for Alzheimer's disease (AD), while the research progress on DYRK1A inhibitors seemed to be in a bottleneck period. In this work, we identified 32 (ZJCK-6-46) as the most potential DYRK1A inhibitor (IC50 = 0.68 nM) through rational design, systematic structural optimization, and comprehensive evaluation. Compound 32 exhibited acceptable in vitro absorption, distribution, metabolism, and excretion (ADME) properties and significantly reduced the expression of p-Tau Thr212 in Tau (P301L) 293T cells and SH-SY5Y cells. Moreover, compound 32 showed favorable bioavailability, blood-brain barrier (BBB) permeability, and the potential of ameliorating cognitive dysfunction by obviously reducing the expression of phosphorylated tau and neuronal loss in vivo, which was deserved as a valuable molecular tool to reveal the role of DYRK1A in the pathogenesis of AD and to further promote the development of anti-AD drugs.

Crosstalk between endothelial cells and dermal papilla entails hair regeneration and angiogenesis during aging.

INTRODUCTION: Tissues maintain their function through interaction with microenvironment. During aging, both hair follicles and blood vessels (BV) in skin undergo degenerative changes. However, it is elusive whether the changes are due to intrinsic aging changes in hair follicles or blood vessels respectively, or their interactions. OBJECTIVE: To explore how hair follicles and blood vessels interact to regulate angiogenesis and hair regeneration during aging. METHODS: Single-cell RNA-sequencing (scRNA-seq) analyses were used to identify the declined ability of dermal papilla (DP) and endothelial cells (ECs) during aging. CellChat and CellCall were performed to investigate interaction between DP and ECs. Single-cell metabolism (scMetabolism) analysis and iPATH were applied to analyze downstream metabolites in DP and ECs. Hair-plucking model and mouse cell organoid model were used for functional studies. RESULTS: During aging, distance and interaction between DP and ECs are decreased. DP interacts with ECs, with decreased EDN1-EDNRA signaling from ECs to DP and CTF1-IL6ST signaling from DP to ECs during aging. ECs-secreted EDN1 binds to DP-expressed EDNRA which enhances Taurine (TA) metabolism to promote hair regeneration. DP-emitted CTF1 binds to ECs-expressed IL6ST which activates alpha-linolenic acid (ALA) metabolism to promote angiogenesis. Activated EDN1-EDNRA-TA signaling promotes hair regeneration in aged mouse skin and in organoid cultures, and increased CTF1-IL6ST-ALA signaling also promotes angiogenesis in aged mouse skin and organoid cultures. CONCLUSIONS: Our finding reveals reciprocal interactions between ECs and DP. ECs releases EDN1 sensed by DP to activate TA metabolism which induces hair regeneration, while DP emits CTF1 signal received by ECs to enhance ALA metabolism which promotes angiogenesis. Our study provides new insights into mutualistic cellular crosstalk between hair follicles and blood vessels, and identifies novel signaling contributing to the interactions of hair follicles and blood vessels in normal and aged skin.

Analytical Study of SH Wave Scattering by a Circular Pipeline in an Inhomogeneous Concrete with Density Variation.

In this paper, the shear horizontal (SH) wave scattering by a circular pipeline in an inhomogeneous concrete with density variation is studied. A model of inhomogeneous concrete with density variation in the form of a polynomial-exponential coupling function is established. By using the complex function method and conformal transformation, the incident and scattering wave field of SH wave in concrete are obtained, and the analytic expression of dynamic stress concentration factor (DSCF) around the circular pipeline is given. The results show that the inhomogeneous density parameters, the wave number of the incident wave and the angle of the incident wave in concrete are important factors affecting the distribution of dynamic stress around the circular pipe in concrete with inhomogeneous density. The research results can provide a theoretical reference and a basis for analyzing the influence of circular pipeline on elastic wave propagation in an inhomogeneous concrete with density variation.

Overview of systematic reviews of probiotics in the prevention and treatment of antibiotic-associated diarrhea in children.

Background: Antibiotics alter the microbial balance commonly resulting in antibiotic-associated diarrhea (AAD). Probiotics may prevent and treat AAD by providing the gut barrier and restoring the gut microflora. This study will overview the Systematic Reviews (SRs) of probiotics in preventing and treating AAD in children. It will also assess the reporting, methodological, and evidence quality of the included SRs to provide evidence for their clinical practice. Methods: After searching PubMed, Embase, Cochrane Library, CNKI, CBM, VIP, and WanFang Data databases, and finally included SRs of probiotics in the prevention and treatment of AAD in children, which were published before 1 October 2022. The reporting, methodological, and evidence quality of the included SRs were assessed by PRISMA 2020 statement, AMSTAR 2 tool, and GRADE system. Results: A total of 20 SRs were included, and the results of PRISMA 2020 showed that 4 out of 20 SRs with relatively complete reporting, and the others within some reporting deficiencies, with scores ranging from 17 points to 26.5 points; the results of AMSTAR 2 showed that 3 SRs belonged to moderate quality level, 10 SRs belonged to low-quality level and 7 SRs being extremely low-quality level; the results of the GRADE system showed that a total of 47 outcomes were reported for the included SRs, three were high-level evidence quality, 16 were medium-level evidence quality, 24 were low-level evidence quality, and four were extremely low-level evidence quality; the results of the Meta-analysis showed that high doses (5-40 billion CFUs per day) of probiotics had a significant effect in the prevention of AAD, but it is too early to conclude the effectiveness and safety of other probiotic drugs for AAD in children, except for Lacticaseibacillus rhamnosus and Saccharomyces boulardii. Conclusion: Current evidence shows that probiotics effectively prevent and treat AAD in children, and the effect of probiotics on pediatric AAD may be a potential dose-response effect. However, the conclusion should be treated with caution due to deficiencies in the methodological, reporting, and evidence quality of the included SRs. Therefore, the methodological, reporting, and evidence quality of relevant SRs still need further improvement. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42022362328.

Spatiotemporal pharmacometabolomics based on ambient mass spectrometry imaging to evaluate the metabolism and hepatotoxicity of amiodarone in HepG2 spheroids.

Three-dimensional (3D) cell spheroid models combined with mass spectrometry imaging (MSI) enables innovative investigation of in vivo-like biological processes under different physiological and pathological conditions. Herein, airflow-assisted desorption electrospray ionization-MSI (AFADESI-MSI) was coupled with 3D HepG2 spheroids to assess the metabolism and hepatotoxicity of amiodarone (AMI). High-coverage imaging of >1100 endogenous metabolites in hepatocyte spheroids was achieved using AFADESI-MSI. Following AMI treatment at different times, 15 metabolites of AMI involved in N-desethylation, hydroxylation, deiodination, and desaturation metabolic reactions were identified, and according to their spatiotemporal dynamics features, the metabolic pathways of AMI were proposed. Subsequently, the temporal and spatial changes in metabolic disturbance within spheroids caused by drug exposure were obtained via metabolomic analysis. The main dysregulated metabolic pathways included arachidonic acid and glycerophospholipid metabolism, providing considerable evidence for the mechanism of AMI hepatotoxicity. In addition, a biomarker group of eight fatty acids was selected that provided improved indication of cell viability and could characterize the hepatotoxicity of AMI. The combination of AFADESI-MSI and HepG2 spheroids can simultaneously obtain spatiotemporal information for drugs, drug metabolites, and endogenous metabolites after AMI treatment, providing an effective tool for in vitro drug hepatotoxicity evaluation.