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1.
Article En | MEDLINE | ID: mdl-38832962

Research on individuals with a younger onset age of schizophrenia is important for identifying neurobiological processes derived from the interaction of genes and the environment that lead to the manifestation of schizophrenia. Schizophrenia has long been recognized as a disorder of dysconnectivity, but it is largely unknown how brain connectivity changes are associated with psychotic symptoms. Twenty-one adolescent-onset schizophrenia (AOS) patients and 21 matched healthy controls (HCs) were recruited and underwent resting-state functional magnetic resonance imaging. Regional homogeneity (ReHo) was used to investigate local brain connectivity alterations in AOS. Regions with significant ReHo changes in patients were selected as "seeds" for further functional connectivity (FC) analysis and Granger causality analysis (GCA), and associations of the obtained functional brain measures with psychotic symptoms in patients with AOS were examined. Compared with HCs, AOS patients showed significantly increased ReHo in the right middle temporal gyrus (MTG), which was positively correlated with PANSS-positive scores, PSYRATS-delusion scores and auditory hallucination scores. With the MTG as the seed, lower connectivity with the bilateral postcentral gyrus (PCG) and higher connectivity with the right precuneus were observed in patients. The reduced FC between the right MTG and bilateral PCG was significantly and positively correlated with hallucination scores. GCA indicated decreased Granger causality from the right MTG to the left middle frontal gyrus (MFG) and from the right MFG to the right MTG in AOS patients, but such effects did not significantly associate with psychotic symptoms. Abnormalities in the connectivity within the MTG and its connectivity with other networks were identified and were significantly correlated with hallucination and delusion ratings. This region may be a key neural substrate of psychotic symptoms in AOS.

2.
PLoS One ; 19(6): e0304689, 2024.
Article En | MEDLINE | ID: mdl-38875285

To explore cost-effective and efficient phytoremediation strategies, this study investigated the distinct roles of earthworm activity and mucus in enhancing Cd phytoextraction from soils contaminated by Festuca arundinacea, focusing on the comparative advantages of selective leaf harvesting versus traditional whole-plant harvesting methods. Our study employed a horticultural trial to explore how earthworm activity and mucus affect Festuca arundinacea' s Cd phytoremediation in soils using control, earthworm, and mucus treatments to examine their respective effects on plant growth and Cd distribution. Earthworm activity increased the dry weight of leaves by 13.5% and significantly increased the dry weights of declining and senescent leaves, surpassing that of the control by more than 40%. Earthworm mucus had a similar, albeit less pronounced, effect on plant growth than earthworm activity. This study not only validated the significant role of earthworm activity in enhancing Cd phytoextraction by Festuca arundinacea, with earthworm activity leading to over 85% of Cd being allocated to senescent tissues that comprise only approximately 20% of the plant biomass, but also highlighted a sustainable and cost-effective approach to phytoremediation by emphasizing selective leaf harvesting supported by earthworm activity. By demonstrating that earthworm mucus alone can redistribute Cd with less efficiency compared to live earthworms, our findings offer practical insights into optimizing phytoremediation strategies and underscore the need for further research into the synergistic effects of biological agents in soil remediation processes.


Biodegradation, Environmental , Cadmium , Festuca , Mucus , Oligochaeta , Plant Leaves , Soil Pollutants , Animals , Oligochaeta/metabolism , Oligochaeta/physiology , Cadmium/metabolism , Plant Leaves/metabolism , Festuca/metabolism , Soil Pollutants/metabolism , Mucus/metabolism , Biomass , Soil/chemistry
4.
Int J Biol Macromol ; 272(Pt 1): 132798, 2024 Jun.
Article En | MEDLINE | ID: mdl-38838896

The emergence of various variants of concern (VOCs) necessitates the development of more efficient vaccines for COVID-19. In this study, we established a rapid and robust production platform for a novel subunit vaccine candidate based on eukaryotic HEK-293 T cells. The immunogenicity of the vaccine candidate was evaluated in pigs. The results demonstrated that the pseudovirus neutralizing antibody (pNAb) titers reached 7751 and 306 for the SARS-CoV-2 Delta and Omicron variants, respectively, after the first boost. Subsequently, pNAb titers further increased to 10,201 and 1350, respectively, after the second boost. Additionally, ELISPOT analysis revealed a robust T-cell response characterized by IFN-γ (171 SFCs/106 cells) and IL-2 (101 SFCs/106 cells) production. Our study demonstrates that a vaccine candidate based on the Delta variant spike protein may provide strong and broad protection against the prototype SARS-CoV-2 and VOCs. Moreover, the strategy for the efficient and stable expression of recombinant proteins utilizing HEK-293 T cells can be employed as a universal platform for future vaccine development.


Antibodies, Neutralizing , COVID-19 Vaccines , COVID-19 , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Vaccines, Subunit , Animals , Humans , HEK293 Cells , COVID-19 Vaccines/immunology , Vaccines, Subunit/immunology , SARS-CoV-2/immunology , Antibodies, Neutralizing/immunology , Swine , COVID-19/prevention & control , COVID-19/immunology , Spike Glycoprotein, Coronavirus/immunology , Antibodies, Viral/immunology , T-Lymphocytes/immunology , Immunogenicity, Vaccine
5.
Opt Express ; 32(9): 16140-16155, 2024 Apr 22.
Article En | MEDLINE | ID: mdl-38859250

In this paper, high-order LP modes based Sagnac interference for temperature sensing are proposed and investigated theoretically. Based on the specific high-order LP modes excited through the mode selective couplers (MSCs), we design a stress-induced Panda-type few-mode fiber (FMF) supporting 4 LP modes and construct a Sagnac interferometer to achieve a highly sensitive temperature sensor. The performances of different LP modes (LP01, LP11, LP21, and LP02) are explored under a single Sagnac interferometer and paralleled Sagnac interferometers, respectively. LP21 mode has the highest temperature sensitivity. Compared with fundamental mode (LP01), the temperature sensitivity based on LP21 mode improved by 18.2% at least. In addition, a way to achieve the enhanced optical Vernier effect is proposed. It should be noted that two Sagnac loops are located in two temperature boxes of opposite variation trends, respectively. Both two Sagnac interferometers act as the sensing element, which is different from the traditional optical Vernier effect. The temperature sensitivity of novel enhanced optical Vernier effect is magnified by 8 times, which is larger than 5 times the traditional Vernier effect. The novel approach avoids measurement errors and improves the stability of the sensing system. The focus of this research is on high-order mode interference, which has important guiding significance for the development of highly sensitive Sagnac sensors.

6.
Angew Chem Int Ed Engl ; : e202407090, 2024 Jun 05.
Article En | MEDLINE | ID: mdl-38840270

Low *CO coverage on the active sites is a major hurdle in the tandem electrocatalysis, resulting in unsatisfied C2H4 production efficiencies. In this work, we developed a synergetic-tandem strategy to construct a copper-based composite catalyst for the electroreduction of CO2 to C2H4, which was constructed via the template-directed polymerization of ultrathin Cu(II) porphyrin organic framework incorporating atomically isolated Cu(II) porphyrin and Cu(II) bipyridine sites on a carbon nanotube (CNT) scaffold, and then Cu2O nanoparticles were uniformly dispersed on the CNT scaffold. The presence of dual active sites within the Cu(II) porphyrin organic framework create a synergetic effect, leading to an increase in local *CO availability to enhance the C-C coupling step implemented on the adjacent Cu2O nanoparticles for further C2H4 production. Accordingly, the resultant catalyst affords an exceptional CO2-to-C2H4 Faradaic efficiency (FEC2H4) of 71.0% at -1.1 V vs reversible hydrogen electrode (RHE), making it one of the most effective copper-based tandem catalysts reported to date. The superior performance of the catalyst is further confirmed through operando infrared spectroscopy and theoretic calculations.

7.
RSC Med Chem ; 15(5): 1675-1685, 2024 May 22.
Article En | MEDLINE | ID: mdl-38784466

The discovery of novel and highly effective P-gp inhibitors is considered to be an effective strategy for overcoming tumor drug resistance. In this paper, a phenotypic screening via a self-constructed synthetic methodology-based library identified a new class of tricyclic spiroindole derivatives with excellent tumor multidrug resistance reversal activity. A stereospecific compound OY-103-B with the best reversal activity was obtained based on a detailed structure-activity relationship study, metabolic stability optimization and chiral resolution. For the VCR-resistant Eca109 cell line (Eca109/VCR), co-administration of 5.0 µM OY-103-B resulted in a reversal fold of up to 727.2, superior to the typical third-generation P-gp inhibitor tariquidar. Moreover, the compound inhibited the proliferation of Eca109/VCR cells in a concentration-dependent manner in plate cloning and flow cytometry. Furthermore, fluorescence substrate accumulation assay and chemotherapeutic drug reversal activity tests demonstrated that OY-103-B reversed tumor drug resistance via P-gp inhibition. In conclusion, this study provides a novel skeleton that inspires the design of new P-gp inhibitors, laying the foundation for the treatment of drug-resistant tumors.

8.
Article En | MEDLINE | ID: mdl-38787662

Accurate image reconstruction is at the heart of diagnostics in medical imaging. Supervised deep learning-based approaches have been investigated for solving inverse problems including image reconstruction. However, these trained models encounter unseen data distributions that are widely shifted from training data during deployment. Therefore, it is essential to assess whether a given input falls within the training data distribution. Current uncertainty estimation approaches focus on providing an uncertainty map to radiologists, rather than assessing the training distribution fit. In this work, we propose a method based on the local Lipschitz metric to distinguish out-of-distribution images from in-distribution with an area under the curve of 99.94% for True Positive Rate versus False Positive Rate. We demonstrate a very strong relationship between the local Lipschitz value and mean absolute error (MAE), supported by a Spearman's rank correlation coefficient of 0.8475, to determine an uncertainty estimation threshold for optimal performance. Through the identification of false positives, we demonstrate the local Lipschitz and MAE relationship can guide data augmentation and reduce uncertainty. Our study was validated using the AUTOMAP architecture for sensor-to-image Magnetic Resonance Imaging (MRI) reconstruction. We demonstrate our approach outperforms baseline techniques of Monte-Carlo dropout and deep ensembles as well as the state-of-the-art Mean Variance Estimation (MVE) network approach. We expand our application scope to MRI denoising and Computed Tomography (CT) sparse-to-full view reconstructions using UNET architectures. We show our approach is applicable to various architectures and applications, especially in medical imaging, where preserving diagnostic accuracy of reconstructed images remains paramount.

9.
Heliyon ; 10(9): e30673, 2024 May 15.
Article En | MEDLINE | ID: mdl-38765154

To address the problem of difficult performance assessment of train control on-board system after recovery from failures, we have proposed a resilience assessment methodology that uses reliability as an indicator of system resilience. Since the system failures are time-dependent, we adopted the Discrete Time Bayesian Network method to obtain the system's reliability before and after failure. Subsequently, we used an exponential recovery model to quantify the system's performance curve during the recovery phase, and finally utilized the resilient triangle area method to quantify its resilience size. Analyzing the CTCS3-300T train control on-board system, we found that the resilience of the system with cold standby redundancy design and hot standby redundancy design were 89.44 % and 87.34 %, respectively, indicating a slight decrease in system performance after recovery from failures compared to pre-failure levels. At that time, it was necessary to adjust operational plans based on actual conditions to avoid greater impact on the railway network. This paper realizes performance resilience of train control on-board system after failure recovery, which can be applied to similar systems and provide theoretical references for realizing intelligent maintenance of the high-speed train.

11.
Nat Med ; 30(5): 1395-1405, 2024 May.
Article En | MEDLINE | ID: mdl-38693247

Cerebral palsy (CP) is the most common motor disability in children. To ascertain the role of major genetic variants in the etiology of CP, we conducted exome sequencing on a large-scale cohort with clinical manifestations of CP. The study cohort comprised 505 girls and 1,073 boys. Utilizing the current gold standard in genetic diagnostics, 387 of these 1,578 children (24.5%) received genetic diagnoses. We identified 412 pathogenic and likely pathogenic (P/LP) variants across 219 genes associated with neurodevelopmental disorders, and 59 P/LP copy number variants. The genetic diagnostic rate of children with CP labeled at birth with perinatal asphyxia was higher than the rate in children without asphyxia (P = 0.0033). Also, 33 children with CP manifestations (8.5%, 33 of 387) had findings that were clinically actionable. These results highlight the need for early genetic testing in children with CP, especially those with risk factors like perinatal asphyxia, to enable evidence-based medical decision-making.


Cerebral Palsy , DNA Copy Number Variations , Exome Sequencing , Genetic Heterogeneity , Humans , Cerebral Palsy/genetics , Female , Male , Child , Child, Preschool , DNA Copy Number Variations/genetics , Exome/genetics , Infant , Genetic Testing , Cohort Studies , Genetic Predisposition to Disease , Infant, Newborn
12.
BMC Med Imaging ; 24(1): 104, 2024 May 03.
Article En | MEDLINE | ID: mdl-38702613

BACKGROUND: The role of isocitrate dehydrogenase (IDH) mutation status for glioma stratification and prognosis is established. While structural magnetic resonance image (MRI) is a promising biomarker, it may not be sufficient for non-invasive characterisation of IDH mutation status. We investigated the diagnostic value of combined diffusion tensor imaging (DTI) and structural MRI enhanced by a deep radiomics approach based on convolutional neural networks (CNNs) and support vector machine (SVM), to determine the IDH mutation status in Central Nervous System World Health Organization (CNS WHO) grade 2-4 gliomas. METHODS: This retrospective study analyzed the DTI-derived fractional anisotropy (FA) and mean diffusivity (MD) images and structural images including fluid attenuated inversion recovery (FLAIR), non-enhanced T1-, and T2-weighted images of 206 treatment-naïve gliomas, including 146 IDH mutant and 60 IDH-wildtype ones. The lesions were manually segmented by experienced neuroradiologists and the masks were applied to the FA and MD maps. Deep radiomics features were extracted from each subject by applying a pre-trained CNN and statistical description. An SVM classifier was applied to predict IDH status using imaging features in combination with demographic data. RESULTS: We comparatively assessed the CNN-SVM classifier performance in predicting IDH mutation status using standalone and combined structural and DTI-based imaging features. Combined imaging features surpassed stand-alone modalities for the prediction of IDH mutation status [area under the curve (AUC) = 0.846; sensitivity = 0.925; and specificity = 0.567]. Importantly, optimal model performance was noted following the addition of demographic data (patients' age) to structural and DTI imaging features [area under the curve (AUC) = 0.847; sensitivity = 0.911; and specificity = 0.617]. CONCLUSIONS: Imaging features derived from DTI-based FA and MD maps combined with structural MRI, have superior diagnostic value to that provided by standalone structural or DTI sequences. In combination with demographic information, this CNN-SVM model offers a further enhanced non-invasive prediction of IDH mutation status in gliomas.


Brain Neoplasms , Diffusion Tensor Imaging , Glioma , Isocitrate Dehydrogenase , Mutation , Humans , Isocitrate Dehydrogenase/genetics , Glioma/diagnostic imaging , Glioma/genetics , Glioma/pathology , Diffusion Tensor Imaging/methods , Retrospective Studies , Male , Female , Middle Aged , Brain Neoplasms/diagnostic imaging , Brain Neoplasms/genetics , Adult , Aged , Neoplasm Grading , Support Vector Machine , Magnetic Resonance Imaging/methods , Neural Networks, Computer , Radiomics
13.
Article En | MEDLINE | ID: mdl-38743107

The amygdala, known for its functional heterogeneity, plays a critical role in the neural mechanism of adolescent major depressive disorder (aMDD). However, changes in its subregional functional networks in relation to stressful factors remain unclear. We recruited 78 comorbidity-free, medication-naive aMDD patients and 40 matched healthy controls (HC) to explore changes in resting-state functional connectivity (FC) across four amygdala subregions: the centromedial nucleus (CM), the basolateral nucleus (LB), the superficial nucleus (SF), and the amygdalostriatal transition area (Astr). Then, we performed partial correlation analysis to investigate the relationship between amygdala subregional FC and stressful factors as measured by the Chinese Version of Family Environment Scale (FES-CV) and the Adolescent Self-Rated Life Events Scale (ASLEC). Compared to HC, aMDD patients demonstrated significantly decreased functional connectivity between the left CM and left precentral gyrus, as well as between left SF and left precentral gyrus, and between left LB and posterior cingulate gyrus (PCC)/precuneus. In aMDD group, left CM-precentral gyrus FC exhibited negative correlation with interpersonal relationship and punishment, and positive correlation with family cohesion and expressiveness. This study reveals distinct patterns of abnormal functional connectivity among amygdala subregions in aMDD. Our findings suggest that the CM network, in particular, may be involved in stress-related factors in aMDD, which provide a potential target for the prevention and treatment of adolescent depression.

14.
Commun Biol ; 7(1): 561, 2024 May 11.
Article En | MEDLINE | ID: mdl-38734744

The WRKY transcription factors play essential roles in a variety of plant signaling pathways associated with biotic and abiotic stress response. The transcriptional activity of many WRKY members are regulated by a class of intrinsically disordered VQ proteins. While it is known that VQ proteins interact with the WRKY DNA-binding domains (DBDs), also termed as the WRKY domains, structural information regarding VQ-WRKY interaction is lacking and the regulation mechanism remains unknown. Herein we report a solution NMR study of the interaction between Arabidopsis WRKY33 and its regulatory VQ protein partner SIB1. We uncover a SIB1 minimal sequence neccessary for forming a stable complex with WRKY33 DBD, which comprises not only the consensus "FxxhVQxhTG" VQ motif but also its preceding region. We demonstrate that the ßN-strand and the extended ßN-ß1 loop of WRKY33 DBD form the SIB1 docking site, and build a structural model of the complex based on the NMR paramagnetic relaxation enhancement and mutagenesis data. Based on this model, we further identify a cluster of positively-charged residues in the N-terminal region of SIB1 to be essential for the formation of a SIB1-WRKY33-DNA ternary complex. These results provide a framework for the mechanism of SIB1-enhanced WRKY33 transcriptional activity.


Arabidopsis Proteins , Arabidopsis , Transcription Factors , Transcription Factors/metabolism , Transcription Factors/chemistry , Transcription Factors/genetics , Arabidopsis Proteins/metabolism , Arabidopsis Proteins/genetics , Arabidopsis Proteins/chemistry , Arabidopsis/genetics , Arabidopsis/metabolism , Gene Expression Regulation, Plant , Protein Binding , Models, Molecular , Amino Acid Sequence , Protein Domains
15.
BMC Psychiatry ; 24(1): 346, 2024 May 08.
Article En | MEDLINE | ID: mdl-38720293

BACKGROUND: Studies have revealed the effects of childhood adversity, anxiety, and negative coping on sleep quality in older adults, but few studies have focused on the association between childhood adversity and sleep quality in rural older adults and the potential mechanisms of this influence. In this study, we aim to evaluate sleep quality in rural older adults, analyze the impact of adverse early experiences on their sleep quality, and explore whether anxiety and negative coping mediate this relationship. METHODS: Data were derived from a large cross-sectional study conducted in Deyang City, China, which recruited 6,318 people aged 65 years and older. After excluding non-agricultural household registration and lack of key information, a total of 3,873 rural older adults were included in the analysis. Structural equation modelling (SEM) was used to analyze the relationship between childhood adversity and sleep quality, and the mediating role of anxiety and negative coping. RESULTS: Approximately 48.15% of rural older adults had poor sleep quality, and older adults who were women, less educated, widowed, or living alone or had chronic illnesses had poorer sleep quality. Through structural equation model fitting, the total effect value of childhood adversity on sleep quality was 0.208 (95% CI: 0.146, 0.270), with a direct effect value of 0.066 (95% CI: 0.006, 0.130), accounting for 31.73% of the total effect; the total indirect effect value was 0.142 (95% CI: 0.119, 0.170), accounting for 68.27% of the total effect. The mediating effects of childhood adversity on sleep quality through anxiety and negative coping were significant, with effect values of 0.096 (95% CI: 0.078, 0.119) and 0.024 (95% CI: 0.014, 0.037), respectively. The chain mediating effect of anxiety and negative coping between childhood adversity and sleep quality was also significant, with an effect value of 0.022 (95% CI: 0.017, 0.028). CONCLUSIONS: Anxiety and negative coping were important mediating factors for rural older adult's childhood adversity and sleep quality. This suggests that managing anxiety and negative coping in older adults may mitigate the negative effects of childhood adversity on sleep quality.


Adaptation, Psychological , Adverse Childhood Experiences , Anxiety , Rural Population , Sleep Quality , Humans , Male , Female , China/epidemiology , Aged , Rural Population/statistics & numerical data , Cross-Sectional Studies , Anxiety/psychology , Anxiety/epidemiology , Adverse Childhood Experiences/statistics & numerical data , Adverse Childhood Experiences/psychology , Aged, 80 and over
16.
Cereb Cortex ; 34(5)2024 May 02.
Article En | MEDLINE | ID: mdl-38706137

Schizophrenia has been considered to exhibit sex-related clinical differences that might be associated with distinctly abnormal brain asymmetries between sexes. One hundred and thirty-two antipsychotic-naïve first-episode patients with schizophrenia and 150 healthy participants were recruited in this study to investigate whether cortical asymmetry would exhibit sex-related abnormalities in schizophrenia. After a 1-yr follow-up, patients were rescanned to obtain the effect of antipsychotic treatment on cortical asymmetry. Male patients were found to show increased lateralization index while female patients were found to exhibit decreased lateralization index in widespread regions when compared with healthy participants of the corresponding sex. Specifically, the cortical asymmetry of male and female patients showed contrary trends in the cingulate, orbitofrontal, parietal, temporal, occipital, and insular cortices. This result suggested male patients showed a leftward shift of asymmetry while female patients showed a rightward shift of asymmetry in these above regions that related to language, vision, emotion, and cognition. Notably, abnormal lateralization indices remained stable after antipsychotic treatment. The contrary trends in asymmetry between female and male patients with schizophrenia together with the persistent abnormalities after antipsychotic treatment suggested the altered brain asymmetries in schizophrenia might be sex-related disturbances, intrinsic, and resistant to the effect of antipsychotic therapy.


Antipsychotic Agents , Cerebral Cortex , Functional Laterality , Magnetic Resonance Imaging , Schizophrenia , Sex Characteristics , Humans , Female , Male , Schizophrenia/drug therapy , Schizophrenia/pathology , Schizophrenia/diagnostic imaging , Schizophrenia/physiopathology , Adult , Cerebral Cortex/diagnostic imaging , Young Adult , Antipsychotic Agents/therapeutic use , Functional Laterality/physiology , Adolescent , Brain Mapping
17.
ACS Nano ; 18(20): 12945-12956, 2024 May 21.
Article En | MEDLINE | ID: mdl-38717846

P3-layered transition oxide cathodes have garnered considerable attention owing to their high initial capacity, rapid Na+ kinetics, and less energy consumption during the synthesis process. Despite these merits, their practical application is hindered by the substantial capacity degradation resulting from unfavorable structural transformations, Mn dissolution and migration. In this study, we systematically investigated the failure mechanisms of P3 cathodes, encompassing Mn dissolution, migration, and the irreversible P3-O3' phase transition, culminating in severe structural collapse. To address these challenges, we proposed an interfacial spinel local interlocking strategy utilizing P3/spinel intergrowth oxide as a proof-of-concept material. As a result, P3/spinel intergrowth oxide cathodes demonstrated enhanced cycling performance. The effectiveness of suppressing Mn migration and maintaining local structure of interfacial spinel local interlocking strategy was validated through depth-etching X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, and in situ synchrotron-based X-ray diffraction. This interfacial spinel local interlocking engineering strategy presents a promising avenue for the development of advanced cathode materials for sodium-ion batteries.

18.
Appl Spectrosc ; : 37028241241325, 2024 Mar 31.
Article En | MEDLINE | ID: mdl-38556929

Based on fluorescence spectroscopy, being combined with several spectral analysis techniques including principal component analysis (PCA), two-dimensional correlation spectroscopy (2D-COS), and moving window 2D-COS, the study disclosed the structural variations of gold nanoclusters capped by thiolactic acid (AuNCs@TLA) induced by Ag(I) ions. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were applied to monitor the morphology evolution of the surface and composition of the nanoclusters induced by Ag(I) ions. Several spectral components, centered at (790, 607) nm, (670, 590) nm, and (740, 670) nm were revealed by 2D-COS analysis, suggesting new luminescent species or groups were generated with the introduction of Ag(I) ions. A two-stage mechanism was revealed for the photoluminescence variations of AuNCs@TLA induced by Ag(I) ion. The first stage was characterized by the emission quench of 790 nm followed by the emerging emission of 607 nm, which was attributed to the anti-galvanic reaction; and the second stage featured by the noticeable growth of the emission's intensity around 670 nm as result of the AuNCs' size effect. The present study will attract more focuses on near-infrared (NIR)-emitted metal nanoclusters and promote their synthesis and utilities.

19.
J Biomed Mater Res A ; 2024 Apr 12.
Article En | MEDLINE | ID: mdl-38606694

This study aimed to evaluate the properties of radiation cross-linked collagen scaffold (RCS) and its efficacy for alveolar ridge preservation (ARP). RCS was prepared from collagen dispersion by electron beam irradiation and freeze-drying. The microstructure, swelling ratio, area alteration and mechanical properties of RCS were characterized. Fifty-four New Zealand rabbits performing incisor extraction on maxilla and mandible were randomly assigned into positive, sham operation or treatment groups. Micro-computed tomography (micro-CT) scans, performed after 1, 4, and 12 weeks of surgery, were to assess changes in ridge height at buccal and palatal side, in ridge width and in micromorphological parameters. Histological analysis accessed socket microarchitecture. The results showed that RCS had stable mechanical properties and morphologic features that provided a reliable physical support for ARP. Dimensional changes in treatment group revealed significantly greater vertical height at buccal (5.32 [3.37, 7.26] mm, p < .0001) and palatal (4.37 [2.66, 6.09] mm, p < .0001) side, and horizontal width at the maxilla (0.16 [0.04, 0.28] mm, p < .01) and mandible (0.33 [0.11, 0.54] mm, p < .01) than those in sham operation group after 12 weeks. The treatment group had advantage than positive group in vertical height preservation, quantitatively. The order and density of bone trabeculae were improved in treatment group. These findings indicated that RCS had the potential to serve as an effective scaffold for ARP.

20.
Materials (Basel) ; 17(7)2024 Mar 29.
Article En | MEDLINE | ID: mdl-38612090

In order to study the multi-mode damage and fracture mechanisms of thin-walled tubular parts with cross inner ribs (longitudinal and transverse inner ribs, LTIRs), the Gurson-Tvergaard-Needleman (GTN) model was modified with a newly proposed stress state function. Thus, tension damage and shear damage were unified by the new stress state function, which was asymmetric with respect to stress triaxiality. Tension damage dominated the modification, which coupled with the shear damage variable, ensured the optimal prediction of fractures of thin-walled tubular parts with LTIRs by the modified GTN model. This included fractures occurring at the non-rib zone (NRZ), the longitudinal rib (LIR) and the interface between the transverse rib (TIR) and the NRZ. Among them, the stripping of material from the outer surface of the tubular part was mainly caused by the shearing of built-up material in front of the rollers under a large wall thickness reduction (ΔT). Shear and tension deformation were the causes of fractures occurring at the NRZ, while axial tension under a large TIR interval (l) mainly resulted in fractures on LIRs. Fractures at the interface between the TIR and NRZ were due to the shearing applied by rib grooves and radial tension during the formation of ribs. This study can provide guidance for the manufacturing of high-performance aluminum alloy thin-walled tubular components with complex inner ribs.

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