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1.
Nature ; 623(7988): 718-723, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37993571

ABSTRACT

Magnetic skyrmions and hopfions are topological solitons1-well-localized field configurations that have gained considerable attention over the past decade owing to their unique particle-like properties, which make them promising objects for spintronic applications. Skyrmions2,3 are two-dimensional solitons resembling vortex-like string structures that can penetrate an entire sample. Hopfions4-9 are three-dimensional solitons confined within a magnetic sample volume and can be considered as closed twisted skyrmion strings that take the shape of a ring in the simplest case. Despite extensive research on magnetic skyrmions, the direct observation of magnetic hopfions is challenging10 and has only been reported in a synthetic material11. Here we present direct observations of hopfions in crystals. In our experiment, we use transmission electron microscopy to observe hopfions forming coupled states with skyrmion strings in B20-type FeGe plates. We provide a protocol for nucleating such hopfion rings, which we verify using Lorentz imaging and electron holography. Our results are highly reproducible and in full agreement with micromagnetic simulations. We provide a unified skyrmion-hopfion homotopy classification and offer insight into the diversity of topological solitons in three-dimensional chiral magnets.

2.
Proc Natl Acad Sci U S A ; 121(18): e2401060121, 2024 Apr 30.
Article in English | MEDLINE | ID: mdl-38648475

ABSTRACT

Electrochromic (EC) displays with electronically regulating the transmittance of solar radiation offer the opportunity to increase the energy efficiency of the building and electronic products and improve the comfort and lifestyle of people. Despite the unique merit and vast application potential of EC technologies, long-awaited EC windows and related visual content displays have not been fully commercialized due to unsatisfactory production cost, durability, color, and complex fabrication processes. Here we develop a unique EC strategy and system based on the natural host and guest interactions to address the above issues. A completely reusable and sustainable EC device has been fabricated with potential advantages of extremely low cost, ideal user-/environment friendly property, and excellent optical modulation, which is benefited from the extracted biomass EC materials and reusable transparent electrodes involved in the system. The as-prepared EC window and nonemissive transparent display also show comprehensively excellent properties: high transmittance change (>85%), broad spectra modulation covering Ultraviolet (UV), Visible (Vis) to Infrared (IR) ranges, high durability (no attenuation under UV radiation for more than 1.5 mo), low open voltage (0.9 V), excellent reusability (>1,200 cycles) of the device's key components and reversibility (>4,000 cycles) with a large transmittance change, and pleasant multicolor. It is anticipated that unconventional exploration and design principles of dynamic host-guest interactions can provide unique insight into different energy-saving and sustainable optoelectronic applications.

3.
Circulation ; 149(9): 684-706, 2024 02 27.
Article in English | MEDLINE | ID: mdl-37994595

ABSTRACT

BACKGROUND: The majority of people with diabetes are susceptible to cardiac dysfunction and heart failure, and conventional drug therapy cannot correct diabetic cardiomyopathy progression. Herein, we assessed the potential role and therapeutic value of USP28 (ubiquitin-specific protease 28) on the metabolic vulnerability of diabetic cardiomyopathy. METHODS: The type 2 diabetes mouse model was established using db/db leptin receptor-deficient mice and high-fat diet/streptozotocin-induced mice. Cardiac-specific knockout of USP28 in the db/db background mice was generated by crossbreeding db/m and Myh6-Cre+/USP28fl/fl mice. Recombinant adeno-associated virus serotype 9 carrying USP28 under cardiac troponin T promoter was injected into db/db mice. High glucose plus palmitic acid-incubated neonatal rat ventricular myocytes and human induced pluripotent stem cell-derived cardiomyocytes were used to imitate diabetic cardiomyopathy in vitro. The molecular mechanism was explored through RNA sequencing, immunoprecipitation and mass spectrometry analysis, protein pull-down, chromatin immunoprecipitation sequencing, and chromatin immunoprecipitation assay. RESULTS: Microarray profiling of the UPS (ubiquitin-proteasome system) on the basis of db/db mouse hearts and diabetic patients' hearts demonstrated that the diabetic ventricle presented a significant reduction in USP28 expression. Diabetic Myh6-Cre+/USP28fl/fl mice exhibited more severe progressive cardiac dysfunction, lipid accumulation, and mitochondrial disarrangement, compared with their controls. On the other hand, USP28 overexpression improved systolic and diastolic dysfunction and ameliorated cardiac hypertrophy and fibrosis in the diabetic heart. Adeno-associated virus serotype 9-USP28 diabetic mice also exhibited less lipid storage, reduced reactive oxygen species formation, and mitochondrial impairment in heart tissues than adeno-associated virus serotype 9-null diabetic mice. As a result, USP28 overexpression attenuated cardiac remodeling and dysfunction, lipid accumulation, and mitochondrial impairment in high-fat diet/streptozotocin-induced type 2 diabetes mice. These results were also confirmed in neonatal rat ventricular myocytes and human induced pluripotent stem cell-derived cardiomyocytes. RNA sequencing, immunoprecipitation and mass spectrometry analysis, chromatin immunoprecipitation assays, chromatin immunoprecipitation sequencing, and protein pull-down assay mechanistically revealed that USP28 directly interacted with PPARα (peroxisome proliferator-activated receptor α), deubiquitinating and stabilizing PPARα (Lys152) to promote Mfn2 (mitofusin 2) transcription, thereby impeding mitochondrial morphofunctional defects. However, such cardioprotective benefits of USP28 were largely abrogated in db/db mice with PPARα deletion and conditional loss-of-function of Mfn2. CONCLUSIONS: Our findings provide a USP28-modulated mitochondria homeostasis mechanism that involves the PPARα-Mfn2 axis in diabetic hearts, suggesting that USP28 activation or adeno-associated virus therapy targeting USP28 represents a potential therapeutic strategy for diabetic cardiomyopathy.


Subject(s)
Diabetes Mellitus, Experimental , Diabetes Mellitus, Type 2 , Diabetic Cardiomyopathies , Induced Pluripotent Stem Cells , Ubiquitin Thiolesterase , Animals , Humans , Mice , Rats , Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Experimental/genetics , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/metabolism , Diabetic Cardiomyopathies/metabolism , Induced Pluripotent Stem Cells/metabolism , Lipids , Mice, Knockout , Myocytes, Cardiac/metabolism , PPAR alpha/metabolism , Streptozocin/metabolism , Streptozocin/therapeutic use , Ubiquitin Thiolesterase/analysis , Ubiquitin Thiolesterase/metabolism
4.
J Pathol ; 263(1): 74-88, 2024 05.
Article in English | MEDLINE | ID: mdl-38411274

ABSTRACT

Fascin actin-bundling protein 1 (Fascin) is highly expressed in a variety of cancers, including esophageal squamous cell carcinoma (ESCC), working as an important oncogenic protein and promoting the migration and invasion of cancer cells by bundling F-actin to facilitate the formation of filopodia and invadopodia. However, it is not clear how exactly the function of Fascin is regulated by acetylation in cancer cells. Here, in ESCC cells, the histone acetyltransferase KAT8 catalyzed Fascin lysine 41 (K41) acetylation, to inhibit Fascin-mediated F-actin bundling and the formation of filopodia and invadopodia. Furthermore, NAD-dependent protein deacetylase sirtuin (SIRT) 7-mediated deacetylation of Fascin-K41 enhances the formation of filopodia and invadopodia, which promotes the migration and invasion of ESCC cells. Clinically, the analysis of cancer and adjacent tissue samples from patients with ESCC showed that Fascin-K41 acetylation was lower in the cancer tissue of patients with lymph node metastasis than in that of patients without lymph node metastasis, and low levels of Fascin-K41 acetylation were associated with a poorer prognosis in patients with ESCC. Importantly, K41 acetylation significantly blocked NP-G2-044, one of the Fascin inhibitors currently being clinically evaluated, suggesting that NP-G2-044 may be more suitable for patients with low levels of Fascin-K41 acetylation, but not suitable for patients with high levels of Fascin-K41 acetylation. © 2024 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.


Subject(s)
Carrier Proteins , Esophageal Neoplasms , Esophageal Squamous Cell Carcinoma , Microfilament Proteins , Sirtuins , Humans , Acetylation , Actins/metabolism , Cell Line, Tumor , Esophageal Neoplasms/pathology , Histone Acetyltransferases/metabolism , Lymphatic Metastasis , Sirtuins/metabolism
5.
J Immunol ; 211(3): 414-428, 2023 08 01.
Article in English | MEDLINE | ID: mdl-37314520

ABSTRACT

Staphylococcus aureus is a common cause of surgical-site infections, including those arising after craniotomy, which is performed to access the brain for the treatment of tumors, epilepsy, or hemorrhage. Craniotomy infection is characterized by complex spatial and temporal dynamics of leukocyte recruitment and microglial activation. We recently identified unique transcriptional profiles of these immune populations during S. aureus craniotomy infection. Epigenetic processes allow rapid and reversible control over gene transcription; however, little is known about how epigenetic pathways influence immunity to live S. aureus. An epigenetic compound library screen identified bromodomain and extraterminal domain-containing (BET) proteins and histone deacetylases (HDACs) as critical for regulating TNF, IL-6, IL-10, and CCL2 production by primary mouse microglia, macrophages, neutrophils, and granulocytic myeloid-derived suppressor cells in response to live S. aureus. Class I HDACs (c1HDACs) were increased in these cell types in vitro and in vivo during acute disease in a mouse model of S. aureus craniotomy infection. However, substantial reductions in c1HDACs were observed during chronic infection, highlighting temporal regulation and the importance of the tissue microenvironment for dictating c1HDAC expression. Microparticle delivery of HDAC and BET inhibitors in vivo caused widespread decreases in inflammatory mediator production, which significantly increased bacterial burden in the brain, galea, and bone flap. These findings identify histone acetylation as an important mechanism for regulating cytokine and chemokine production across diverse immune cell lineages that is critical for bacterial containment. Accordingly, aberrant epigenetic regulation may be important for promoting S. aureus persistence during craniotomy infection.


Subject(s)
Staphylococcal Infections , Staphylococcus aureus , Animals , Mice , Epigenesis, Genetic , Cytokines/metabolism , Craniotomy , Leukocytes/metabolism , Inflammation Mediators
6.
Brain ; 147(7): 2496-2506, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38325327

ABSTRACT

We evaluated whether spike ripples, the combination of epileptiform spikes and ripples, provide a reliable and improved biomarker for the epileptogenic zone compared with other leading interictal biomarkers in a multicentre, international study. We first validated an automated spike ripple detector on intracranial EEG recordings. We then applied this detector to subjects from four centres who subsequently underwent surgical resection with known 1-year outcomes. We evaluated the spike ripple rate in subjects cured after resection [International League Against Epilepsy Class 1 outcome (ILAE 1)] and those with persistent seizures (ILAE 2-6) across sites and recording types. We also evaluated available interictal biomarkers: spike, spike-gamma, wideband high frequency oscillation (HFO, 80-500 Hz), ripple (80-250 Hz) and fast ripple (250-500 Hz) rates using previously validated automated detectors. The proportion of resected events was computed and compared across subject outcomes and biomarkers. Overall, 109 subjects were included. Most spike ripples were removed in subjects with ILAE 1 outcome (P < 0.001), and this was qualitatively observed across all sites and for depth and subdural electrodes (P < 0.001 and P < 0.001, respectively). Among ILAE 1 subjects, the mean spike ripple rate was higher in the resected volume (0.66/min) than in the non-removed tissue (0.08/min, P < 0.001). A higher proportion of spike ripples were removed in subjects with ILAE 1 outcomes compared with ILAE 2-6 outcomes (P = 0.06). Among ILAE 1 subjects, the proportion of spike ripples removed was higher than the proportion of spikes (P < 0.001), spike-gamma (P < 0.001), wideband HFOs (P < 0.001), ripples (P = 0.009) and fast ripples (P = 0.009) removed. At the individual level, more subjects with ILAE 1 outcomes had the majority of spike ripples removed (79%, 38/48) than spikes (69%, P = 0.12), spike-gamma (69%, P = 0.12), wideband HFOs (63%, P = 0.03), ripples (45%, P = 0.01) or fast ripples (36%, P < 0.001) removed. Thus, in this large, multicentre cohort, when surgical resection was successful, the majority of spike ripples were removed. Furthermore, automatically detected spike ripples localize the epileptogenic tissue better than spikes, spike-gamma, wideband HFOs, ripples and fast ripples.


Subject(s)
Electrocorticography , Humans , Male , Female , Adult , Electrocorticography/methods , Young Adult , Adolescent , Electroencephalography/methods , Middle Aged , Epilepsy/physiopathology , Epilepsy/surgery , Child , Brain Waves/physiology , Brain/physiopathology
7.
Lab Invest ; 104(6): 102069, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38670317

ABSTRACT

Tissue gene expression studies are impacted by biological and technical sources of variation, which can be broadly classified into wanted and unwanted variation. The latter, if not addressed, results in misleading biological conclusions. Methods have been proposed to reduce unwanted variation, such as normalization and batch correction. A more accurate understanding of all causes of variation could significantly improve the ability of these methods to remove unwanted variation while retaining variation corresponding to the biological question of interest. We used 17,282 samples from 49 human tissues in the Genotype-Tissue Expression data set (v8) to investigate patterns and causes of expression variation. Transcript expression was transformed to z-scores, and only the most variable 2% of transcripts were evaluated and clustered based on coexpression patterns. Clustered gene sets were assigned to different biological or technical causes based on histologic appearances and metadata elements. We identified 522 variable transcript clusters (median: 11 per tissue) among the samples. Of these, 63% were confidently explained, 16% were likely explained, 7% were low confidence explanations, and 14% had no clear cause. Histologic analysis annotated 46 clusters. Other common causes of variability included sex, sequencing contamination, immunoglobulin diversity, and compositional tissue differences. Less common biological causes included death interval (Hardy score), disease status, and age. Technical causes included blood draw timing and harvesting differences. Many of the causes of variation in bulk tissue expression were identifiable in the Tabula Sapiens data set of single-cell expression. This is among the largest explorations of the underlying sources of tissue expression variation. It uncovered expected and unexpected causes of variable gene expression and demonstrated the utility of matched histologic specimens. It further demonstrated the value of acquiring meaningful tissue harvesting metadata elements to use for improved normalization, batch correction, and analysis of both bulk and single-cell RNA-seq data.


Subject(s)
Gene Expression Profiling , Humans , Organ Specificity , Cluster Analysis
8.
Am J Epidemiol ; 2024 May 29.
Article in English | MEDLINE | ID: mdl-38806447

ABSTRACT

Polygenic risk scores (PRS) are rapidly emerging as a way to measure disease risk by aggregating multiple genetic variants. Understanding the interplay of PRS with environmental factors is critical for interpreting and applying PRS in a wide variety of settings. We develop an efficient method for simultaneously modeling gene-environment correlations and interactions using PRS in case control studies. We use a logistic-normal regression modeling framework to specify the disease risk and PRS distribution in the underlying population and propose joint inference across the two models using the retrospective likelihood of the case-control data. Extensive simulation studies demonstrate the flexibility of the method in trading-off bias and efficiency for the estimation of various model parameters compared to the standard logistic regression or a case-only analysis for gene-environment interactions, or a control-only analysis for gene-environment correlations. Finally using simulated case-control data sets within the UK Biobank study, we demonstrate the power of our method for its ability to recover results from the full prospective cohort for the detection of an interaction between long-term oral contraceptive use and PRS on the risk of breast cancer. This method is computationally efficient and implemented in a user-friendly R package.

9.
Anal Chem ; 96(18): 7257-7264, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38664861

ABSTRACT

Confocal fluorescence imaging of fine structures of the cell membrane is important for understanding their biofunctions but is often neglected due to the lack of an effective method. Herein, we develop new amphiphilic rhodamine fluorescent probe RMGs in combination with basal imaging for this purpose. The probes show high signal-to-noise ratio and brightness and low internalization rate, making them suitable for imaging the fine substructures of the cell membrane. Using the representative probe RMG3, we not only observed the cell pseudopodia and intercellular nanotubes but also monitored the formation of migrasomes in real time. More importantly, in-depth imaging studies on more cell lines revealed for the first time that hepatocellular carcinoma cells secreted much more adherent extracellular vesicles than other cell lines, which might serve as a potential indicator of liver cells. We believe that RMGs may be useful for investigating the fine structures of the cell membrane.


Subject(s)
Cell Membrane , Fluorescent Dyes , Rhodamines , Fluorescent Dyes/chemistry , Rhodamines/chemistry , Humans , Cell Membrane/chemistry , Optical Imaging , Microscopy, Confocal/methods , Surface-Active Agents/chemistry
10.
Anal Chem ; 96(14): 5437-5445, 2024 Apr 09.
Article in English | MEDLINE | ID: mdl-38529794

ABSTRACT

The research on fluorescent rotors for viscosity has attracted extensive interest to better comprehend the close relationships of microviscosity variations with related diseases. Although scientists have made great efforts, fluorescent probes for cellular viscosity with both aggregation-induced emissions (AIEs) and large Stokes shifts to improve sensing properties have rarely been reported. Herein, we first report four new meso-C═N-substituted BODIPY-based rotors with large Stokes shifts, investigate their viscosity/AIE characteristics, and perform cellular imaging of the viscosity in subcellular organelles. Interestingly, the meso-C═N-phenyl group-substituted probe 6 showed an obvious 594 nm fluorescence enhancement in glycerol and a moderate 650 nm red AIE emission in water. Further, on attaching CF3 to the phenyl group, a similar phenomenon was observed for 7 with red-shifted emissions, attributed to the introduction of a phenyl group, which plays a key role in the red AIE emissions and large Stokes shifts. Comparatively, for phenyl-group-free probes, both the meso-C═N-trifluoroethyl group and thiazole-substituted probes (8 and 9) exhibited good viscosity-responsive properties, while no AIE was observed due to the absence of phenyl groups. For cellular experiments, 6 and 9 showed good lysosomal and mitochondrial targeting properties, respectively, and were further successfully used for imaging viscosity through the preincubation of monensin and lipopolysaccharide (LPS), indicating that C═N polar groups potentially work as rotatable moieties and organelle-targeting groups, and the targeting difference might be ascribed to increased charges of thiazole. Therefore, in this study, we investigated the structural relationships of four meso-C═N BODIPY-based rotors with respect to their viscosity/AIE characteristics, subcellular-targeting ability, and cellular imaging for viscosity, potentially serving as AIE fluorescent probes with large Stokes shifts for subcellular viscosity imaging.


Subject(s)
Boron Compounds , Fluorescent Dyes , Organelles , Fluorescent Dyes/chemistry , Viscosity , Thiazoles
11.
Hum Brain Mapp ; 45(5): e26672, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38549429

ABSTRACT

Mother-child interaction is highly dynamic and reciprocal. Switching roles in these back-and-forth interactions serves as a crucial feature of reciprocal behaviors while the underlying neural entrainment is still not well-studied. Here, we designed a role-controlled cooperative task with dual EEG recording to explore how differently two brains interact when mothers and children hold different roles. When children were actors and mothers were observers, mother-child interbrain synchrony emerged primarily within the theta oscillations and the frontal lobe, which highly correlated with children's attachment to their mothers (self-reported by mothers). When their roles were reversed, this synchrony was shifted to the alpha oscillations and the central area and associated with mothers' perception of their relationship with their children. The results suggested an observer-actor neural alignment within the actor's oscillations, which was related to the actor-toward-observer emotional bonding. Our findings contribute to the understanding of how interbrain synchrony is established and dynamically changed during mother-child reciprocal interaction.


Subject(s)
Brain , Mothers , Female , Humans , Mothers/psychology , Brain/diagnostic imaging , Frontal Lobe , Mother-Child Relations/psychology , Diencephalon
12.
J Transl Med ; 22(1): 358, 2024 Apr 16.
Article in English | MEDLINE | ID: mdl-38627718

ABSTRACT

BACKGROUND: Diabetic macular edema (DME) is a leading cause of vision loss in patients with diabetes. This study aimed to develop and evaluate an OCT-omics prediction model for assessing anti-vascular endothelial growth factor (VEGF) treatment response in patients with DME. METHODS: A retrospective analysis of 113 eyes from 82 patients with DME was conducted. Comprehensive feature engineering was applied to clinical and optical coherence tomography (OCT) data. Logistic regression, support vector machine (SVM), and backpropagation neural network (BPNN) classifiers were trained using a training set of 79 eyes, and evaluated on a test set of 34 eyes. Clinical implications of the OCT-omics prediction model were assessed by decision curve analysis. Performance metrics (sensitivity, specificity, F1 score, and AUC) were calculated. RESULTS: The logistic, SVM, and BPNN classifiers demonstrated robust discriminative abilities in both the training and test sets. In the training set, the logistic classifier achieved a sensitivity of 0.904, specificity of 0.741, F1 score of 0.887, and AUC of 0.910. The SVM classifier showed a sensitivity of 0.923, specificity of 0.667, F1 score of 0.881, and AUC of 0.897. The BPNN classifier exhibited a sensitivity of 0.962, specificity of 0.926, F1 score of 0.962, and AUC of 0.982. Similar discriminative capabilities were maintained in the test set. The OCT-omics scores were significantly higher in the non-persistent DME group than in the persistent DME group (p < 0.001). OCT-omics scores were also positively correlated with the rate of decline in central subfield thickness after treatment (Pearson's R = 0.44, p < 0.001). CONCLUSION: The developed OCT-omics model accurately assesses anti-VEGF treatment response in DME patients. The model's robust performance and clinical implications highlight its utility as a non-invasive tool for personalized treatment prediction and retinal pathology assessment.


Subject(s)
Diabetes Mellitus , Diabetic Retinopathy , Macular Edema , Humans , Angiogenesis Inhibitors/therapeutic use , Diabetes Mellitus/drug therapy , Diabetic Retinopathy/diagnostic imaging , Diabetic Retinopathy/drug therapy , Intravitreal Injections , Machine Learning , Macular Edema/complications , Macular Edema/diagnostic imaging , Macular Edema/drug therapy , Radiomics , Retrospective Studies , Tomography, Optical Coherence/methods , Vascular Endothelial Growth Factors
13.
Magn Reson Med ; 92(1): 158-172, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38411277

ABSTRACT

PURPOSE: Abnormalities in cerebral veins are a common finding in many neurological diseases, yet there is a scarcity of MRI techniques to assess venous hemodynamic function. The present study aims to develop a noncontrast technique to measure a novel blood flow circulatory measure, venous transit time (VTT), which denotes the time it takes for water to travel from capillary to major veins. METHODS: The proposed sequence, venous transit time imaging by changes in T1 relaxation (VICTR), is based on the notion that as water molecules transition from the tissue into the veins, they undergo a change in T1 relaxation time. The validity of the measured VTT was tested by studying the VTT along the anatomically known flow trajectory of venous vessels as well as using a physiological vasoconstrictive challenge of caffeine ingestion. Finally, we compared the VTT measured with VICTR MRI to a bolus-tracking method using gadolinium-based contrast agent. RESULTS: VTT was measured to be 3116.3 ± 326.0 ms in the posterior superior sagittal sinus (SSS), which was significantly longer than 2865.0 ± 390.8 ms at the anterior superior sagittal sinus (p = 0.004). The test-retest assessment showed an interclass correlation coefficient of 0.964. VTT was significantly increased by 513.8 ± 239.3 ms after caffeine ingestion (p < 0.001). VTT measured with VICTR MRI revealed a strong correlation (R = 0.84, p = 0.002) with that measured with the contrast-based approach. VTT was found inversely correlated to cerebral blood flow and venous oxygenation across individuals. CONCLUSION: A noncontrast MRI technique, VICTR MRI, was developed to measure the VTT of the brain.


Subject(s)
Cerebral Veins , Magnetic Resonance Imaging , Humans , Male , Adult , Female , Blood Flow Velocity/physiology , Cerebral Veins/diagnostic imaging , Magnetic Resonance Imaging/methods , Cerebrovascular Circulation/physiology , Reproducibility of Results , Caffeine/pharmacology , Contrast Media , Young Adult , Image Processing, Computer-Assisted/methods , Hemodynamics , Magnetic Resonance Angiography/methods
14.
Plant Cell Environ ; 2024 May 13.
Article in English | MEDLINE | ID: mdl-38738504

ABSTRACT

Plants synthesise a vast array of volatile organic compounds (VOCs), which serve as chemical defence and communication agents in their interactions with insect herbivores. Although nitrogen (N) is a critical resource in the production of plant metabolites, its regulatory effects on defensive VOCs remain largely unknown. Here, we investigated the effect of N content in tomato (Solanum lycopersicum) on the tobacco cutworm (Spodoptera litura), a notorious agricultural pest, using biochemical and molecular experiments in combination with insect behavioural and performance analyses. We observed that on tomato leaves with different N contents, S. litura showed distinct feeding preference and growth and developmental performance. Particularly, metabolomics profiling revealed that limited N availability conferred resistance upon tomato plants to S. litura is likely associated with the biosynthesis and emission of the volatile metabolite α-humulene as a repellent. Moreover, exogenous application of α-humulene on tomato leaves elicited a significant repellent response against herbivores. Thus, our findings unravel the key factors involved in N-mediated plant defence against insect herbivores and pave the way for innovation of N management to improve the plant defence responses to facilitate pest control strategies within agroecosystems.

15.
Acc Chem Res ; 56(16): 2127-2138, 2023 Aug 15.
Article in English | MEDLINE | ID: mdl-37432731

ABSTRACT

ConspectusThe controlled doping of organic semiconductors (OSCs) is crucial not only for improving the performance of electronic and optoelectronic devices but also for enabling efficient thermoelectric conversion and spintronic applications. The mechanism of doping for OSCs is fundamentally different from that of their inorganic counterparts. In particular, the interplay between dopants and host materials is complicated considering the low dielectric constant, strong lattice-charge interaction, and flexible nature of materials. Recent experimental breakthroughs in the molecular design of dopants and the precise doping with high spatial resolution call for more profound understandings as to how the dopant interacts with the charge introduced to OSCs and how the admixture of dopants alters the electronic properties of host materials before one can exploit controllable doping to realize desired functionalities.By employing state-of-the-art computational tools, we revealed the effects of doping in representative and emerging organic and coordination polymers aiming toward thermoelectric and spintronic applications. We showed that dopants and hosts should be taken as an integrated system, and the type of charge-transfer interaction between them is the key for spin polarization. First, we found doping-induced modifications to the electronic band in a potassium-doped coordination polymer, an n-type thermoelectric material. The charge localization due to the Coulomb interaction between the completely ionized dopant and the injected charge on the polymer backbone and also the polaron band formation at low doping levels are responsible for the nonmonotonic temperature dependence of the conductivity and Seebeck coefficient observed in recent experiments. The mechanistic insights gained from these results have provided important guidelines on how to control the doping level and working temperature to achieve a high thermoelectric conversion efficiency. Next, we demonstrated that the ionized dopants scatter charge carriers via screened Coulomb interactions, and it may become a dominant scattering mechanism in doped polymers. After incorporating the ionized dopant scattering mechanism in PEDOT:Tos, a p-type thermoelectric polymer, we were able to reproduce the measured Seebeck coefficient-electrical conductivity relationship spanning a wide range of doping levels, highlighting the importance of ionized dopant scattering in charge transport.In the two cases described above, charge injection is enabled by integral charge transfer between the dopant and host polymers. In a third example, we showed that a novel type of stacked two-dimensional polymer, conjugated covalent organic frameworks (COFs) with closed-shell electronic structures, can be spin polarized by iodine doping via fractional charge transfer even at high doping levels. We then manifested that magnetization can be attained in nonmagnetic materials lacking metal d electrons and further designed two new COFs with tunable spintronic structure and magnetic interactions after the iodine doping. These findings have suggested a practical route to enable spin polarization in nonradical materials by chemical doping via orbital hybridization, which holds great promise for flexible spintronic applications.

16.
Chemistry ; 30(7): e202303345, 2024 Feb 01.
Article in English | MEDLINE | ID: mdl-37964711

ABSTRACT

Homonuclear dual-atomic catalysts showcase unique electronic modulation due to their dual metal centres, providing new direction in development of efficient catalysts for CO2 electroreduction. This article highlights a few cutting-edge homonuclear dual-atomic catalysts, focusing on their inherent advantages in efficient and selective CO2 electroreduction, to spotlight the potential application of dual-atomic catalysts in CO2 electroreduction.

17.
Cerebrovasc Dis ; 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38964301

ABSTRACT

INTRODUCTION: There has been an increasing demand for imaging methods that provide a comprehensive evaluation of intracranial clot and collateral circulation, which are helpful for clinical decision-making and predicting functional outcomes. We aimed to quantitatively evaluate acute intracranial clot burden and collaterals on high-resolution magnetic resonance imaging (HR-MRI). METHODS: We analyzed acute ischemic stroke patients with internal carotid artery or middle cerebral artery occlusion in a prospective multicenter study. The clot burden was scored on a scale of 0-10 based on the clot location on HR-MRI. The collateral score was assigned on a scale of 0-3 using the minimum intensity projection from HR-MRI. Uni- and multivariable logistic regression analyses were performed to assess their correlation with clinical outcome (modified Rankin Scale >2 at 90 days). Thresholds were defined to dichotomize into low and high score groups and predictive performances were assessed for clinical and radiologic outcomes. RESULTS: Ninety-nine patients (mean age of 60.77 ± 11.54 years) were included in the analysis. The interobserver correlation was 0.89 (95% CI: 0.77-0.95) for the clot burden score and 0.78 (95% CI: 0.53-0.90) for the collateral score. Multivariable logistic regression analysis demonstrated that the collateral score (odds ratio: 0.41, 95% CI: 0.19-0.90) was significantly associated with clinical outcomes. A better functional outcome was observed in the group with clot burden scores greater than 7 (p=0.011). A smaller final infarct size and a higher diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score were observed in the group with collateral scores greater than 1 (all p<0.05). CONCLUSIONS: HR-MRI offers a new tool for quantitative assessment of clot burden and collaterals simultaneously in future clinical practices and research endeavors.

18.
Helicobacter ; 29(3): e13063, 2024.
Article in English | MEDLINE | ID: mdl-38874128

ABSTRACT

BACKGROUND: The overall benefits of the newly introduced family-based Helicobacter pylori (H. pylori) infection control and management (FBCM) and screen-and-treat strategies in preventing multiple upper gastrointestinal diseases at national level in China have not been explored. We investigate the cost-effectiveness of these strategies in the whole Chinese population. MATERIALS AND METHODS: Decision trees and Markov models of H. pylori infection-related non-ulcer dyspepsia (NUD), peptic ulcer disease (PUD), and gastric cancer (GC) were developed to simulate the cost-effectiveness of these strategies in the whole 494 million households in China. The main outcomes include cost-effectiveness, life years (LY), quality-adjusted life year (QALY), and incremental cost-effectiveness ratio (ICER). RESULTS: When compared with no-screen strategy, both FBCM and screen-and-treat strategies reduced the number of new cases of NUD, PUD, PUD-related deaths, and the prevalence of GC, and cancer-related deaths. The costs saved by these two strategies were $1467 million and $879 million, quality-adjusted life years gained were 227 million and 267 million, and life years gained were 59 million and 69 million, respectively. Cost-effectiveness analysis showed that FBCM strategy costs -$6.46/QALY and -$24.75/LY, and screen-and-treat strategy costs -$3.3/QALY and -$12.71/LY when compared with no-screen strategy. Compared to the FBCM strategy, the screen-and-treat strategy reduced the incidence of H. pylori-related diseases, added 40 million QALYs, and saved 10 million LYs, but at the increased cost of $588 million. Cost-effectiveness analysis showed that screen-and-treat strategy costs $14.88/QALY and $59.5/LY when compared with FBCM strategy. The robustness of the results was also verified. CONCLUSIONS: Both FBCM and screen-and-treat strategies are highly cost-effective in preventing NUD, PUD, and GC than the no-screen strategy in Chinese families at national level. As FBCM strategy is more practical and efficient, it is expected to play a more important role in preventing familial H. pylori infection and also serves as an excellent reference for other highly infected societies.


Subject(s)
Cost-Benefit Analysis , Helicobacter Infections , Humans , Helicobacter Infections/economics , Helicobacter Infections/prevention & control , Helicobacter Infections/diagnosis , China/epidemiology , Helicobacter pylori , Quality-Adjusted Life Years , Male , Middle Aged , Stomach Neoplasms/prevention & control , Stomach Neoplasms/economics , Female , Mass Screening/economics , Adult , Gastrointestinal Diseases/microbiology , Gastrointestinal Diseases/prevention & control , Gastrointestinal Diseases/economics , Aged , Infection Control/economics , Infection Control/methods , Peptic Ulcer/prevention & control , Peptic Ulcer/economics , East Asian People
19.
Inorg Chem ; 2024 Jul 07.
Article in English | MEDLINE | ID: mdl-38973091

ABSTRACT

The development of low-cost and efficient photocatalysts to achieve water splitting to hydrogen (H2) is highly desirable but remains challenging. Herein, we design and synthesize two porous polymers (Co-Salen-P and Fe-Salen-P) by covalent bonding of salen metal complexes and pyrene chromophores for photocatalytic H2 evolution. The catalytic results demonstrate that the two polymers exhibit excellent catalytic performance for H2 generation in the absence of additional noble-metal photosensitizers and cocatalysts. Particularly, the H2 generation rate of Co-Salen-P reaches as high as 542.5 µmol g-1 h-1, which is not only 6 times higher than that of Fe-Salen-P but also higher than a large amount of reported Pt-assisted photocatalytic systems. Systematic studies show that Co-Salen-P displays faster charge separation and transfer efficiencies, thereby accounting for the significantly improved photocatalytic activity. This study provides a facile and efficient way to fabricate high-performance photocatalysts for H2 production.

20.
Phys Chem Chem Phys ; 26(2): 1303-1313, 2024 Jan 03.
Article in English | MEDLINE | ID: mdl-38108089

ABSTRACT

External pressure can regulate the photophysical property and charge transport performance of organic semiconductors, however, the underlying mechanism at the microscopic level is still elusive. Using thermal vibrational correlation function coupled quantum mechanics/molecular mechanics and full quantum charge transfer rate theory, we systematically explore the influence of pressure on fluorescence emission and charge transport behaviours of representative cyclooctatetrathiophene (COTh). It is found that, upon pressurization, the intramolecular configurations of COTh became more twisted, leading to the blue-shifted emission. The fluorescence quantum efficiency (FQE) of COTh crystals decreases monotonically in a wide pressure range of 0-4.38 GPa, because the increase of intermolecular electronic energy transfer rate constant (keet) is larger than the decrease of internal conversion rate constant (kic), and the variation of keet is dominant. The decrease in kic is attributed to the decreasing reorganization energy, reflecting the suppression of the low-frequency flipping vibrations of four thiophene rings and the high-frequency stretching vibrations of central cyclooctatetraene, while the keet increase is due to the simultaneous increase in exciton coupling and spectra overlap. Moreover, we predicted that the hole mobility of COTh increases monotonically by nearly an order of magnitude from 0.39 to 3.00 cm2 V-1 s-1 upon compression, because of the increase in transfer integral and the decrease of charged reorganization energy. Furthermore, its hole mobility exhibits obvious anisotropy. Our work systematically builds the external pressure, molecular packing, luminescence and transport properties relationships of organic semiconductors and provides theoretical guidance for the rational design of pressure responsive organic semiconductors with excellent photoelectric performance.

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