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1.
Proc Natl Acad Sci U S A ; 121(5): e2309384121, 2024 Jan 30.
Article in English | MEDLINE | ID: mdl-38252835

ABSTRACT

High-quality specimen preparation plays a crucial role in cryo-electron microscopy (cryo-EM) structural analysis. In this study, we have developed a reliable and convenient technique called the graphene sandwich method for preparing cryo-EM specimens. This method involves using two layers of graphene films that enclose macromolecules on both sides, allowing for an appropriate ice thickness for cryo-EM analysis. The graphene sandwich helps to mitigate beam-induced charging effect and reduce particle motion compared to specimens prepared using the traditional method with graphene support on only one side, therefore improving the cryo-EM data quality. These advancements may open new opportunities to expand the use of graphene in the field of biological electron microscopy.


Subject(s)
Graphite , Cryoelectron Microscopy , Data Accuracy , Motion
2.
BMC Bioinformatics ; 25(1): 35, 2024 Jan 23.
Article in English | MEDLINE | ID: mdl-38254030

ABSTRACT

BACKGROUND: Natural proteins occupy a small portion of the protein sequence space, whereas artificial proteins can explore a wider range of possibilities within the sequence space. However, specific requirements may not be met when generating sequences blindly. Research indicates that small proteins have notable advantages, including high stability, accurate resolution prediction, and facile specificity modification. RESULTS: This study involves the construction of a neural network model named TopoProGenerator(TPGen) using a transformer decoder. The model is trained with sequences consisting of a maximum of 65 amino acids. The training process of TopoProGenerator incorporates reinforcement learning and adversarial learning, for fine-tuning. Additionally, it encompasses a stability predictive model trained with a dataset comprising over 200,000 sequences. The results demonstrate that TopoProGenerator is capable of designing stable small protein sequences with specified topology structures. CONCLUSION: TPGen has the ability to generate protein sequences that fold into the specified topology, and the pretraining and fine-tuning methods proposed in this study can serve as a framework for designing various types of proteins.


Subject(s)
Amino Acids , Electric Power Supplies , Amino Acid Sequence , Language , Learning
3.
BMC Genomics ; 25(1): 133, 2024 Feb 02.
Article in English | MEDLINE | ID: mdl-38302866

ABSTRACT

BACKGROUND: WD40 proteins, which are highly prevalent in eukaryotes, play important roles in plant development and stress responses. However, systematic identification and exploration of WD40 proteins in tobacco have not yet been conducted. RESULTS: In this study, a total of 399 WD40 regulatory genes were identified in common tobacco (Nicotiana tabacum). Gene structure and motif analysis revealed structural and functional diversity among different clades of tobacco WD40 regulatory genes. The expansion of tobacco WD40 regulatory genes was mainly driven by segmental duplication and purifying selection. A potential regulatory network of NtWD40s suggested that NtWD40s might be regulated by miRNAs and transcription factors in various biological processes. Expression pattern analysis via transcriptome analysis and qRT-PCR revealed that many NtWD40s exhibited tissue-specific expression patterns and might be involved in various biotic and abiotic stresses. Furthermore, we have validated the critical role of NtTTG1, which was located in the nuclei of trichome cells, in enhancing the drought tolerance of tobacco plants. CONCLUSIONS: Our study provides comprehensive information to better understand the evolution of WD40 regulatory genes and their roles in different stress responses in tobacco.


Subject(s)
Drought Resistance , Nicotiana , Nicotiana/genetics , Plant Proteins/genetics , Plant Proteins/metabolism , Transcription Factors/metabolism , Gene Expression Profiling , Stress, Physiological/genetics , Gene Expression Regulation, Plant , Phylogeny
4.
BMC Plant Biol ; 24(1): 134, 2024 Feb 26.
Article in English | MEDLINE | ID: mdl-38403644

ABSTRACT

BACKGROUND: N6-methyladenosine (m6A) is one of the common internal RNA modifications found in eukaryotes. The m6A modification can regulate various biological processes in organisms through the modulation of alternative splicing, alternative polyadenylation, folding, translation, localization, transport, and decay of multiple types of RNA, without altering the nucleotide sequence. The three components involved in m6A modification, namely writer, eraser, and reader, mediate the abundance of RNA m6A modification through complex collaborative actions. Currently, research on m6A regulatory genes in plants is still in its infancy. RESULTS: In this study, we identified 52 candidate m6A regulatory genes in common tobacco (Nicotiana tabacum L.). Gene structure, conserved domains, and motif analysis showed structural and functional diversity among different subgroups of tobacco m6A regulatory genes. The amplification of m6A regulatory genes were mainly driven by polyploidization and dispersed duplication, and duplicated genes evolved through purified selection. Based on the potential regulatory network and expression pattern analysis of m6A regulatory genes, a significant number of m6A regulatory genes might play important roles in growth, development, and stress response processes. Furthermore, we have confirmed the critical role of NtFIP37B, an m6A writer gene in tobacco, in enhancing drought resistance. CONCLUSIONS: This study provides useful information for better understanding the evolution of m6A regulatory genes and the role of m6A modification in tobacco stress response, and lays the foundation for further elucidating the function of m6A regulatory genes in tobacco.


Subject(s)
Adenosine/analogs & derivatives , Drought Resistance , Nicotiana , Nicotiana/genetics , Genes, Regulator , RNA , Gene Expression Regulation, Plant , Stress, Physiological/genetics , Phylogeny
5.
J Biol Inorg Chem ; 29(3): 315-330, 2024 04.
Article in English | MEDLINE | ID: mdl-38722397

ABSTRACT

Eighteen novel Ti(IV) complexes stabilized by different chelating amino-bis(phenolato) (ONNO, ONON, ONOO) ligands and 2,6-dipicolinic acid as a second chelator were synthesized with isolated yields ranging from 79 to 93%. Complexes were characterized by 1H and 13C-NMR spectroscopy, as well as by HRMS and X-Ray diffraction analysis. The good to excellent aqueous stability of these Ti(IV) complexes can be modulated by the substitutions on the 2-position of the phenolato ligands. Most of the synthesized Ti(IV) complexes demonstrated potent inhibitory activity against Hela S3 and Hep G2 tumor cells. Among them, the naphthalenyl based Salan type 2j, 2-picolylamine based [ONON] type 2n and N-(2-hydroxyethyl) based [ONOO] type 2p demonstrated up to 40 folds enhanced cytotoxicity compared to cisplatin together with a significantly reduced activity against healthy AML12 cells. The three Ti(IV) complexes exhibited fast cellular uptake by Hela S3 cells and induced almost exclusively apoptosis. 2j could trigger higher level of ROS generation than 2p and 2n.


Subject(s)
Antineoplastic Agents , Coordination Complexes , Drug Screening Assays, Antitumor , Picolinic Acids , Titanium , Humans , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/chemical synthesis , Picolinic Acids/chemistry , Picolinic Acids/pharmacology , Picolinic Acids/chemical synthesis , Coordination Complexes/chemistry , Coordination Complexes/pharmacology , Coordination Complexes/chemical synthesis , Structure-Activity Relationship , Titanium/chemistry , Titanium/pharmacology , HeLa Cells , Apoptosis/drug effects , Molecular Structure , Cell Proliferation/drug effects
6.
Eur J Nucl Med Mol Imaging ; 51(6): 1685-1697, 2024 May.
Article in English | MEDLINE | ID: mdl-38246909

ABSTRACT

Due to the heterogeneity of tumors, strategies to improve the effectiveness of dual-targeting tracers in tumor diagnostics have been intensively practiced. In this study, the radiolabeled [18F]AlF-NOTA-FAPI-RGD (denoted as [18F]AlF-LNC1007), a dual-targeting heterodimer tracer targeting both fibroblast activation protein (FAP) and integrin αvß3 to enhance specific tumor uptake and retention, was synthesized and evaluated. The tracer was compared with [68Ga]Ga-LNC1007 in preclinical and clinical settings. METHODS: The preparation of [18F]AlF- and 68Ga-labeled FAPI-RGD was carried out with an optimized protocol. The stability was tested in PBS and fetal bovine serum (FBS). Cellular uptake and in vivo distribution of the two products were compared and carried out on the U87MG cell line and its xenograft model. The safety and dosimetry of [18F]AlF-LNC1007 PET/CT scan were evaluated in six patients with malignant tumors. RESULTS: Two radiolabeling protocols of [18F]AlF-/[68Ga]Ga-LNC1007 were developed and optimized to give a high yield of tracers with good stability. In vivo microPET images showed that the two tracers exhibited comparable pharmacokinetic characteristics, with high tumor uptake and prolonged tumor retention. In vivo distribution data showed that the target-to-non-target ratios of [18F]AlF-LNC1007 were similar to[68Ga]Ga-LNC1007. A total of six patients underwent [18F]AlF-LNC1007 PET/CT evaluation while two had head-to-head [18F]FDG PET/CT scans. The total body effective dose was 9.94E-03 mSv/MBq. The biodistribution curve showed optimal normal organ uptake with high tumor uptake and long retention of up to 3h p.i., and notably, the tumor-to-background ratio increased over time. CONCLUSION: We successfully prepared an [18F]AlF-LNC1007 dual-targeting PET probe with comparable performances as [68Ga]Ga-LNC1007. With prolonged tumor retention and tumor specificity, it produced good imaging quality in preclinical and clinical translational studies, indicating that [18F]AlF-LNC1007 is a promising non-invasive tracer for detecting tumors expressing FAP and/or integrin avß3, with the prospect of clinical implementation.


Subject(s)
Aluminum Compounds , Endopeptidases , Fluorides , Fluorine Radioisotopes , Membrane Proteins , Oligopeptides , Positron Emission Tomography Computed Tomography , Positron Emission Tomography Computed Tomography/methods , Humans , Animals , Mice , Fluorine Radioisotopes/chemistry , Cell Line, Tumor , Oligopeptides/chemistry , Oligopeptides/pharmacokinetics , Female , Tissue Distribution , Gallium Radioisotopes , Pilot Projects , Male , Isotope Labeling , Neoplasms/diagnostic imaging , Middle Aged , Radiopharmaceuticals/pharmacokinetics , Radiopharmaceuticals/chemistry
7.
Chemistry ; : e202402363, 2024 Aug 06.
Article in English | MEDLINE | ID: mdl-39105655

ABSTRACT

In this work, nine new rare-earth metal-organic frameworks (RE-MOFs, where RE = Lu(III), Yb(III), Tm(III), Er(III), Ho(III), Dy(III), Tb(III), Gd(III), and Eu(III)) isostructural to Zr-MOF-808 are synthesized, characterized, and studied regarding their photophysical properties. Materials with high crystallinity and surface area are obtained from a reproducible synthetic procedure that involves the use of two fluorinated modulators. At the same time, these new RE-MOFs display tunable photoluminescent properties due to efficient linker-to-metal energy transfer promoted by the antenna effect, resulting in a series of RE-MOFs displaying lanthanoid-based emissions spanning the visible and near-infrared regions of the electromagnetic spectrum.

8.
Gastrointest Endosc ; 2024 May 09.
Article in English | MEDLINE | ID: mdl-38734256

ABSTRACT

BACKGROUND AND AIM: After endoscopic full-thickness resection (EFTR), defects require a reliable and sustained closure. We present a novel, through-the-scope "bow-tie" (TTS-BT) closing device enabling direct defect closure without scope withdrawal. This preclinical study aimed to evaluate the feasibility and safety of this device for large defect closure after EFTR in a porcine model. METHODS: Exposed EFTR was performed for virtual lesions > 2 cm in the stomach of twelve pigs. Subsequently, TTS-BT closing devices were used for defect closure. Conventional metal clips were used to close any remaining defects. Gastroscopy was performed for 8 weeks to examine the wound sites and the pigs were subsequently sacrificed. After sacrificing the pigs, the wound healing was histologically verified by hematoxylin-eosin (HE) staining. The primary outcome was a successful closure rate, while the secondary outcomes were complete healing rate, closure time, and incidence of adverse events. RESULTS: The median long and short diameters of perforations were 4.0 (3.0-6.0) cm and 3.0 (2.0-4.0) cm, respectively. Defect closure using novel TTS-BT closure devices and conventional metal clips was successfully performed in all pigs. Complete healing was achieved in the defects of 12 pigs. The median closure time was 13 (9-38) minutes. No serious adverse events occurred during the 8-week follow-up. CONCLUSIONS: The novel TTS-BT closure device is feasible and safe for closing large gastric perforations and could be a promising tool for clinical practice.

9.
Neurochem Res ; 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-39088164

ABSTRACT

Depression and anxiety disorders are prevalent stress-related neuropsychiatric disorders and involve multiple molecular changes and dysfunctions across various brain regions. However, the specific and shared pathophysiological mechanisms occurring in these regions remain unclear. Previous research used a rat model of chronic mild stress (CMS) to segregate and identify depression-susceptible, anxiety-susceptible, and insusceptible groups; then the proteomes of six distinct brain regions (the hippocampus, prefrontal cortex, hypothalamus, pituitary, olfactory bulb, and striatum) were separately and quantitatively analyzed. To gain a comprehensive and systematic understanding of the molecular abnormalities, this study aimed to investigate and compare differential proteomics data from the six regions. Differentially expressed proteins (DEPs) were identified in between specific regions and across all regions and subjected to a series of bioinformatics analyses. Regional comparisons showed that stress-induced proteomic changes and corresponding gene ontology and pathway enrichments were largely distinct, attributable to differences in cell populations, protein compositions, and brain functions of these areas. Additionally, a notable degree of overlap in the significantly enriched terms was identified, potentially suggesting strong connections in the enrichment across different regions. Furthermore, intra-regional and inter-regional protein-protein interaction networks and drug-target-DEP networks were constructed. Integrated analysis of the three association networks in the six regions, along with the DisGeNET database, identified ten DEPs as potential targets for anti-depression/anxiety drugs. Collectively, these findings revealed commonalities and differences across different brain regions at the protein level induced by CMS, and identified several novel protein targets for the development of new therapeutics for depression and anxiety.

10.
Mol Pharm ; 2024 Jul 29.
Article in English | MEDLINE | ID: mdl-39069891

ABSTRACT

Nectin cell adhesion molecule 4 (Nectin-4) is overexpressed in various malignant tumors and has emerged as a promising target for tumor imaging. Bicyclic peptides, known for their conformational rigidity, metabolic stability, and membrane permeability, are ideal tracers for positron emission tomography (PET) imaging. In this study, we evaluated the feasibility of visualizing Nectin-4-positive tumors using radiolabeled bicyclic peptide derivatives and optimized the pharmacokinetics of radiotracers by introducing PEG chains of different lengths. Five PEGylated radiotracers radiolabeled with 68Ga3+ exhibited high radiochemical purity and stability. As the chain length increased, the Log D values decreased from -2.32 ± 0.13 to -2.50 ± 0.16, indicating a gradual increase in the hydrophilicity of the radiotracers. In vitro cell-binding assay results showed that the PEGylated bicyclic peptide exhibits nanomolar affinity, and blocking experiments confirmed the specific binding of the tracers to the Nectin-4 receptor. In vivo PET imaging and biodistribution studies in SW780 and 5637 xenograft mice showed that [68Ga]Ga-NOTA-PEG12-BP demonstrated optimal pharmacokinetics, characterized by rapid and good tumor uptake, faster background clearance, and improved tumor-to-tissue contrast. Finally, compared with 18F-FDG, PET imaging, in vivo blocking assays of [68Ga]Ga-NOTA-PEG12-BP and histological staining confirmed that specific tumor uptake was mediated by Nectin-4 receptors. The results indicated that [68Ga]Ga-NOTA-PEG12-BP was a promising PET radiotracer for Nectin-4 targeting, with applications for clinical translation.

11.
Pharmacol Res ; 206: 107283, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38964523

ABSTRACT

The maintenance of nuclear shape is essential for cellular homeostasis and disruptions in this process have been linked to various pathological conditions, including cancer, laminopathies, and aging. Despite the significance of nuclear shape, the precise molecular mechanisms controlling it are not fully understood. In this study, we have identified the YEATS domain-containing protein 4 (GAS41) as a previously unidentified factor involved in regulating nuclear morphology. Genetic ablation of GAS41 in colorectal cancer cells resulted in significant abnormalities in nuclear shape and inhibited cancer cell proliferation both in vitro and in vivo. Restoration experiments revealed that wild-type GAS41, but not a YEATS domain mutant devoid of histone H3 lysine 27 acetylation or crotonylation (H3K27ac/cr) binding, rescued the aberrant nuclear phenotypes in GAS41-deficient cells, highlighting the importance of GAS41's binding to H3K27ac/cr in nuclear shape regulation. Further experiments showed that GAS41 interacts with H3K27ac/cr to regulate the expression of key nuclear shape regulators, including LMNB1, LMNB2, SYNE4, and LEMD2. Mechanistically, GAS41 recruited BRD2 and the Mediator complex to gene loci of these regulators, promoting their transcriptional activation. Disruption of GAS41-H3K27ac/cr binding caused BRD2, MED14 and MED23 to dissociate from gene loci, leading to nuclear shape abnormalities. Overall, our findings demonstrate that GAS41 collaborates with BRD2 and the Mediator complex to control the expression of crucial nuclear shape regulators.


Subject(s)
Cell Nucleus , Colorectal Neoplasms , Transcription Factors , Colorectal Neoplasms/metabolism , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Humans , Animals , Transcription Factors/metabolism , Transcription Factors/genetics , Cell Nucleus/metabolism , Nuclear Proteins/metabolism , Nuclear Proteins/genetics , Cell Line, Tumor , Cell Proliferation , Mice , Histones/metabolism , Mice, Nude , Protein Serine-Threonine Kinases/metabolism , Protein Serine-Threonine Kinases/genetics , HCT116 Cells , Bromodomain Containing Proteins
12.
J Cardiovasc Pharmacol ; 84(1): 118-123, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38547516

ABSTRACT

ABSTRACT: This study seeks to identify the anticoagulant efficacy of rivaroxaban treatment on thrombi detected using echocardiography of the left atrial appendage in 275 patients with persistent atrial fibrillation. During follow-up after 9-24 weeks of rivaroxaban treatment, patients were divided into "effective group" (n = 143) and "ineffective group" (n = 132) according to the thrombolytic effect of the drug. Left atrial diameter (LAD), left atrial ejection fraction (LAEF), left ventricular ejection fraction (LVEF), mean diameter of left atrial appendage (LAAD mean ), angle between left atrial appendage and left atrium (LAA-A), velocity of blood flow in left atrial appendage (LAA-v), and thrombus size were compared before and after drug administration. Following treatment, LAEF, LVEF, and LAA-v values were greater and LAD and LAAD mean values were lower in the effective ( P < 0.05). Logistic regression analysis showed significant correlations of LAD, LAEF, LVEF, LAA-A, and LAA-v with anticoagulant efficacy ( P < 0.05). The efficacy of rivaroxaban in treatment of left atrial auricular thrombosis in patients with persistent AF was correlated with LAD, LAEF, LVEF, LAA-A, and LAA-v. Multivariate logistic regression analysis further revealed LAEF [odds ratio (OR) 1.7, 95% confidence interval (CI), 0.45-16.9, P = 0.008], 3D-EF (OR 6.4, 95% CI, 1.06-16.9, P = 0.039) and left ventricular global longitudinal strain (OR 18.0, 95% CI, 1.38-35.68, P = 0.028) as factors related to left atrial appendage thrombus. Echocardiography with global longitudinal strain assessment could be effectively utilized to evaluate the functional parameters of LAA and thus aid in predicting the safety of rivaroxaban as an anticoagulation agent.


Subject(s)
Atrial Appendage , Atrial Fibrillation , Echocardiography, Three-Dimensional , Factor Xa Inhibitors , Rivaroxaban , Humans , Atrial Fibrillation/drug therapy , Atrial Fibrillation/physiopathology , Atrial Fibrillation/diagnostic imaging , Atrial Fibrillation/diagnosis , Female , Male , Rivaroxaban/therapeutic use , Rivaroxaban/administration & dosage , Aged , Middle Aged , Treatment Outcome , Atrial Appendage/diagnostic imaging , Atrial Appendage/physiopathology , Atrial Appendage/drug effects , Factor Xa Inhibitors/adverse effects , Factor Xa Inhibitors/therapeutic use , Thrombosis/diagnostic imaging , Thrombosis/drug therapy , Thrombosis/physiopathology , Predictive Value of Tests , Atrial Function, Left/drug effects , Thrombolytic Therapy , Ventricular Function, Left/drug effects , Time Factors
13.
Cell Biol Toxicol ; 40(1): 31, 2024 May 20.
Article in English | MEDLINE | ID: mdl-38767771

ABSTRACT

Mitochondrial dysfunction contributes to cerebral ischemia-reperfusion (CI/R) injury, which can be ameliorated by Sirtuin-3 (SIRT3). Under stress conditions, the SIRT3-promoted mitochondrial functional recovery depends on both its activity and expression. However, the approach to enhance SIRT3 activity after CI/R injury remains unelucidated. In this study, Sprague-Dawley (SD) rats were intracranially injected with either adeno-associated viral Sirtuin-1 (AAV-SIRT1) or AAV-sh_SIRT1 before undergoing transient middle cerebral artery occlusion (tMCAO). Primary cortical neurons were cultured and transfected with lentiviral SIRT1 (LV-SIRT1) and LV-sh_SIRT1 respectively before oxygen-glucose deprivation/reoxygenation (OGD/R). Afterwards, rats and neurons were respectively treated with a selective SIRT3 inhibitor, 3-(1H-1,2,3-triazol-4-yl) pyridine (3-TYP). The expression, function, and related mechanism of SIRT1 were investigated by Western Blot, flow cytometry, immunofluorescence staining, etc. After CI/R injury, SIRT1 expression decreased in vivo and in vitro. The simulation and immune-analyses reported strong interaction between SIRT1 and SIRT3 in the cerebral mitochondria before and after CI/R. SIRT1 overexpression enhanced SIRT3 activity by increasing the deacetylation of SIRT3, which ameliorated CI/R-induced cerebral infarction, neuronal apoptosis, oxidative stress, neurological and motor dysfunction, and mitochondrial respiratory chain dysfunction, promoted mitochondrial biogenesis, and retained mitochondrial integrity and mitochondrial morphology. Meanwhile, SIRT1 overexpression alleviated OGD/R-induced neuronal death and mitochondrial bioenergetic deficits. These effects were reversed by AAV-sh_SIRT1 and the neuroprotective effects of SIRT1 were partially offset by 3-TYP. These results suggest that SIRT1 restores the structure and function of mitochondria by activating SIRT3, offering neuroprotection against CI/R injury, which signifies a potential approach for the clinical management of cerebral ischemia.


Subject(s)
Brain Ischemia , Mitochondria , Neurons , Rats, Sprague-Dawley , Reperfusion Injury , Sirtuin 1 , Sirtuin 3 , Animals , Sirtuin 1/metabolism , Sirtuin 1/genetics , Reperfusion Injury/metabolism , Reperfusion Injury/pathology , Mitochondria/metabolism , Male , Sirtuin 3/metabolism , Sirtuin 3/genetics , Neurons/metabolism , Neurons/pathology , Rats , Brain Ischemia/metabolism , Brain Ischemia/pathology , Infarction, Middle Cerebral Artery/metabolism , Infarction, Middle Cerebral Artery/pathology , Apoptosis , Sirtuins
14.
Oecologia ; 204(4): 885-898, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38643441

ABSTRACT

Ungulate grazing involves multiple components, including defoliation, dung and urine return, and trampling, which supply offsetting or synergistic effects on plant community composition and productivity (ANPP), but these effects have not been fully studied. Plant functional traits may reflect the response of plants to disturbance and their impact on ecosystem functions. Species turnover and intraspecific trait variation (ITV) are important drivers of community trait composition. We conducted a simulated grazing experiment in a steppe grassland in northern China to examine the effects of defoliation, dung and urine return, and trampling on community-weighted mean (CWM), functional diversity (FD) and ANPP, and to disentangle the roles of species turnover and ITV in driving these changes. We found that defoliation had a dominant effect on CWMs and FDs of all four traits through species turnover and ITV, respectively, resulting in a convergence of traits towards as more resource-acquisitive strategy. Dung-urine return resulted in more resource-acquisitive community traits mainly through ITV, whereas there were no significant effects on FDs except for leaf C/N. Trampling increased CWM of leaf dry matter content primarily driven by ITV, and had no significant effect on FDs. Furthermore, our simulated grazing positively affected ANPP, primarily due to nutrient additions from dung and urine, and ITV largely explained the variation in ANPP. These findings highlight the multifaceted effects of grazing components on community structure and ANPP, and the significance of ITV in shaping grassland plant communities and productivity.


Subject(s)
Grassland , Animals , Herbivory , Ecosystem , China , Plants
15.
J Biomed Inform ; 156: 104673, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38862083

ABSTRACT

OBJECTIVE: Pneumothorax is an acute thoracic disease caused by abnormal air collection between the lungs and chest wall. Recently, artificial intelligence (AI), especially deep learning (DL), has been increasingly employed for automating the diagnostic process of pneumothorax. To address the opaqueness often associated with DL models, explainable artificial intelligence (XAI) methods have been introduced to outline regions related to pneumothorax. However, these explanations sometimes diverge from actual lesion areas, highlighting the need for further improvement. METHOD: We propose a template-guided approach to incorporate the clinical knowledge of pneumothorax into model explanations generated by XAI methods, thereby enhancing the quality of the explanations. Utilizing one lesion delineation created by radiologists, our approach first generates a template that represents potential areas of pneumothorax occurrence. This template is then superimposed on model explanations to filter out extraneous explanations that fall outside the template's boundaries. To validate its efficacy, we carried out a comparative analysis of three XAI methods (Saliency Map, Grad-CAM, and Integrated Gradients) with and without our template guidance when explaining two DL models (VGG-19 and ResNet-50) in two real-world datasets (SIIM-ACR and ChestX-Det). RESULTS: The proposed approach consistently improved baseline XAI methods across twelve benchmark scenarios built on three XAI methods, two DL models, and two datasets. The average incremental percentages, calculated by the performance improvements over the baseline performance, were 97.8% in Intersection over Union (IoU) and 94.1% in Dice Similarity Coefficient (DSC) when comparing model explanations and ground-truth lesion areas. We further visualized baseline and template-guided model explanations on radiographs to showcase the performance of our approach. CONCLUSIONS: In the context of pneumothorax diagnoses, we proposed a template-guided approach for improving model explanations. Our approach not only aligns model explanations more closely with clinical insights but also exhibits extensibility to other thoracic diseases. We anticipate that our template guidance will forge a novel approach to elucidating AI models by integrating clinical domain expertise.


Subject(s)
Artificial Intelligence , Deep Learning , Pneumothorax , Humans , Pneumothorax/diagnostic imaging , Algorithms , Tomography, X-Ray Computed/methods , Medical Informatics/methods
16.
Environ Res ; 250: 118523, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38382664

ABSTRACT

BACKGROUND: Most previous research on the environmental epidemiology of childhood atopic eczema, rhinitis and wheeze is limited in the scope of risk factors studied. Our study adopted a machine learning approach to explore the role of the exposome starting already in the preconception phase. METHODS: We performed a combined analysis of two multi-ethnic Asian birth cohorts, the Growing Up in Singapore Towards healthy Outcomes (GUSTO) and the Singapore PREconception Study of long Term maternal and child Outcomes (S-PRESTO) cohorts. Interviewer-administered questionnaires were used to collect information on demography, lifestyle and childhood atopic eczema, rhinitis and wheeze development. Data training was performed using XGBoost, genetic algorithm and logistic regression models, and the top variables with the highest importance were identified. Additive explanation values were identified and inputted into a final multiple logistic regression model. Generalised structural equation modelling with maternal and child blood micronutrients, metabolites and cytokines was performed to explain possible mechanisms. RESULTS: The final study population included 1151 mother-child pairs. Our findings suggest that these childhood diseases are likely programmed in utero by the preconception and pregnancy exposomes through inflammatory pathways. We identified preconception alcohol consumption and maternal depressive symptoms during pregnancy as key modifiable maternal environmental exposures that increased eczema and rhinitis risk. Our mechanistic model suggested that higher maternal blood neopterin and child blood dimethylglycine protected against early childhood wheeze. After birth, early infection was a key driver of atopic eczema and rhinitis development. CONCLUSION: Preconception and antenatal exposomes can programme atopic eczema, rhinitis and wheeze development in utero. Reducing maternal alcohol consumption during preconception and supporting maternal mental health during pregnancy may prevent atopic eczema and rhinitis by promoting an optimal antenatal environment. Our findings suggest a need to include preconception environmental exposures in future research to counter the earliest precursors of disease development in children.


Subject(s)
Dermatitis, Atopic , Exposome , Machine Learning , Respiratory Sounds , Rhinitis , Humans , Dermatitis, Atopic/epidemiology , Female , Rhinitis/epidemiology , Male , Child, Preschool , Singapore/epidemiology , Pregnancy , Maternal Exposure , Child , Adult , Prenatal Exposure Delayed Effects/epidemiology , Infant , Cohort Studies
17.
BMC Psychiatry ; 24(1): 404, 2024 May 29.
Article in English | MEDLINE | ID: mdl-38811881

ABSTRACT

BACKGROUND: Coupled with its rising prevalence, Autism spectrum disorder (ASD) has become a globally recognized public health concern. Nevertheless, large-scale, multicenter studies that analyze the epidemiology of ASD in China are relatively scarce. METHODS: Literature searches were conducted in PubMed/Medline, Embase, the Cochrane Library, Wanfang Data Knowledge Service Platform, China Biology Medicine database (CBM), China Science and Technology Journal Database (CSTJ), and China National Knowledge Infrastructure (CNKI) to retrieve studies published before April 8, 2023, related to ASD prevalence among children aged 0 to 14 years in mainland China. Meta-analysis was conducted using RevMan 5.2 and Stata 14.0. RESULTS: Twenty-one articles were included. The ASD prevalence among children in mainland China has been 0.7% (95% confidence interval(CI): 0.006-0.008) since 2017. The prevalence of ASD among boys was 1.0% (95% CI: 0.008-0.011), which was significantly higher than that among girls at 0.2% (95% CI: 0.002-0.003), with a statistically significant difference (OR = 3.198, 95% CI: 2.489-4.109, P = 0.000). Among the included studies, 18 reported an ASD prevalence of 0.8% (95% CI: 0.007-0.010), while 3 studies reported an autistic disorder (AD) prevalence of 0.7% (95% CI: 0.006-0.008). The prevalence of autism among urban children was 23.9% (95% CI: 0.149-0.328), and in rural areas, it was 0.7% (95% CI: 0.002-0.013), with no statistically significant difference (OR = 1.342, 95% CI: 0.258-6.975, P = 0.727). Regression analysis showed that factors such as region (P = 0.000), age (P = 0.000), study period (P = 0.000), sample size (P = 0.000), sampling method (P = 0.002), population source (P = 0.000), disease type (P = 0.000), quality score of the study (P = 0.000), and diagnostic criteria (P = 0.000) might have contributed to the heterogeneity in ASD prevalence. CONCLUSION: The prevalence of ASD in China from 2017 to 2023 was 7/1000, showing an upward trend compared to that before 2017 (26.50/10,000). The male-to-female prevalence ratio was 5:1.The overall prevalence remained significantly lower than that reported in foreign countries.


Subject(s)
Autism Spectrum Disorder , Humans , Autism Spectrum Disorder/epidemiology , China/epidemiology , Prevalence , Child , Adolescent , Male , Child, Preschool , Female , Infant
18.
Cell Biochem Funct ; 42(2): e3965, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38457283

ABSTRACT

A highly efficient chlorobenzene-degrading strain was isolated from the sludge of a sewage treatment plant associated with a pharmaceutical company. The strain exhibited a similarity of over 99.9% with multiple strains of Paenarthrobacter ureafaciens. Therefore, the strain was suggested to be P. ureafaciens LY. This novel strain exhibited a broad spectrum of pollutant degradation capabilities, effectively degrading chlorobenzene and other organic pollutants, such as 1, 2, 4-trichlorobenzene, phenol, and xylene. Moreover, P. ureafaciens LY co-metabolized mixtures of chlorobenzene with 1, 2, 4-trichlorobenzene or phenol. Evaluation of its degradation efficiency showed that it achieved an impressive degradation rate of 94.78% for chlorobenzene within 8 h. The Haldane-Andrews model was used to describe the growth of P. ureafaciens LY under specific pollutants and its concentrations, revealing a maximum specific growth rate (µmax ) of 0.33 h-1 . The isolation and characterization of P. ureafaciens LY, along with its ability to degrade chlorobenzene, provides valuable insights for the development of efficient and eco-friendly approaches to mitigate chlorobenzene contamination. Additionally, investigation of the degradation performance of the strain in the presence of other pollutants offers important information for understanding the complexities of co-metabolism in mixed-pollutant environments.


Subject(s)
Chlorobenzenes , Environmental Pollutants , Micrococcaceae , Biodegradation, Environmental , Chlorobenzenes/metabolism , Phenol , Pharmaceutical Preparations
19.
Immun Ageing ; 21(1): 10, 2024 Jan 27.
Article in English | MEDLINE | ID: mdl-38279177

ABSTRACT

BACKGROUND: Age-related changes in the ovarian microenvironment are linked to impaired fertility in women. Macrophages play important roles in ovarian tissue homeostasis and immune surveillance. However, the impact of aging on ovarian macrophage function and ovarian homeostasis remains poorly understood. METHODS: Senescence-associated beta-galactosidase staining, immunohistochemistry, and TUNEL staining were used to assess senescence and apoptosis, respectively. Flow cytometry was employed to evaluate mitochondrial membrane potential (MMP) and apoptosis in granulosa cells lines (KGN), and macrophages phagocytosis. After a 2-month treatment with low molecular weight Chitosan (LMWC), ovarian tissues from mice were collected for comprehensive analysis. RESULTS: Compared with the liver and uterus, the ovary displayed accelerated aging in an age-dependent manner, which was accompanied by elevated levels of inflammatory factors and apoptotic cells, and impaired macrophage phagocytic activity. The aged KGN cells exhibited elevated reactive oxygen species (ROS) and apoptotic levels alongside decreased MMP. H2O2-induced aging macrophages showed reduced phagocytosis function. Moreover, there were excessive aging macrophages with impaired phagocytosis in the follicular fluid of patients with diminished ovarian reserve (DOR). Notably, LMWC administration alleviated ovarian aging by enhancing macrophage phagocytosis and promoting tissue homeostasis. CONCLUSIONS: Aging ovarian is characterized by an accumulation of aging and apoptotic granulosa cells, an inflammatory response and macrophage phagocytosis dysfunction. In turn, impaired phagocytosis of macrophage contributes to insufficient clearance of aging and apoptotic granulosa cells and the increased risk of DOR. Additionally, LMWC emerges as a potential therapeutic strategy for age-related ovarian dysfunction.

20.
Eur Neurol ; 87(3): 130-139, 2024.
Article in English | MEDLINE | ID: mdl-38981445

ABSTRACT

INTRODUCTION: This meta-analysis aimed to explore the association of perivascular spaces (PVS) burden with the risks of future stroke events and mortality in patients with ischemic stroke and transient ischemic attack (TIA). METHODS: We systematically searched PubMed, Embase, and Cochrane database from inception to December 31, 2023. We included eligible studies that reported adjusted estimated effects for future intracranial hemorrhage (ICH), ischemic stroke, and mortality with baseline PVS burden in patients with ischemic stroke and TIA. Data were pooled using an inverse-variance method for the fixed effects (FE) model and a restricted maximum likelihood method for the random effects (RE) model. RESULTS: Thirteen observational studies (5 prospective, 8 retrospective) were included, comprising 20,256 patients. Compared to 0-10 PVS at basal ganglia (BG-PVS), a higher burden (>10) of BG-PVS was significantly associated with an increased risk of future ICH (adjusted hazards ratio [aHR] 2.79, 95% confidence interval [CI]: 1.16-6.73, RE model; aHR 2.14, 95% CI: 1.34-3.41, FE model; I2 = 64%, n = 17,084 from four studies) followed up for at least 1 year. There was no significant association between >10 BG-PVS and ICH within 7 days after reperfusion therapy (adjusted odds ratio [aOR] 1.69, 95% CI: 0.74-3.88, RE model; aOR 1.43, 95% CI: 0.89-2.88, FE model; I2 = 67%, n = 1,176 from four studies). We did not detect a significant association of recurrent ischemic stroke, mortality, or disability with BG-PVS burden. Neither >10 PVS at centrum semiovale (CSO-PVS) nor increasing CSO-PVS burden was significantly associated with the risk of future intracranial hemorrhage or ischemic stroke recurrence. CONCLUSIONS: Current evidence suggests that a higher BG-PVS burden may be associated with an increased risk of future ICH in patients with ischemic stroke and TIA.


Subject(s)
Ischemic Attack, Transient , Ischemic Stroke , Humans , Glymphatic System/pathology , Intracranial Hemorrhages/etiology , Risk Factors
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