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1.
J Am Chem Soc ; 146(21): 14697-14704, 2024 May 29.
Article in English | MEDLINE | ID: mdl-38753349

ABSTRACT

Chiral superstructures with unique chiroptical properties that are not inherent in the individual units are essential in applications such as 3D displays, spintronic devices, biomedical sensors, and beyond. Generally, chiral superstructures are obtained by tedious procedures exploring various physical and chemical forces to break spatial symmetry during the self-assembly of discrete nanoparticles. In contrast, we herein present a simple and efficient approach to chiral superstructures by intercalating small chiral molecules into preformed achiral superstructures. As a model system, the chiral CdSe nanoplatelet (NPL) superlattice exhibits a giant and tunable optical activity with the highest g-factor reaching 3.09 × 10-2 to the excitonic transition of the NPL superlattice, nearly 2 orders of magnitude higher than that of the corresponding separated chiral NPLs. The theoretical analysis reveals that the chiral deformation in the NPL superlattice induced by the chiral perturbation of the small chiral molecules is critical to the observed huge optical activity. We anticipate that this research lays a foundation for understanding and applying chiral inorganic nanosystems.

2.
Front Neurosci ; 18: 1352409, 2024.
Article in English | MEDLINE | ID: mdl-38595975

ABSTRACT

As a novel measure for irregularity and complexity of the spontaneous fluctuations of brain activities, brain entropy (BEN) has attracted much attention in resting-state functional magnetic resonance imaging (rs-fMRI) studies during the last decade. Previous studies have shown its associations with cognitive and mental functions. While most previous research assumes BEN is approximately stationary during scan sessions, the brain, even at its resting state, is a highly dynamic system. Such dynamics could be characterized by a series of reoccurring whole-brain patterns related to cognitive and mental processes. The present study aims to explore the time-varying feature of BEN and its potential links with general cognitive ability. We adopted a sliding window approach to derive the dynamical brain entropy (dBEN) of the whole-brain functional networks from the HCP (Human Connectome Project) rs-fMRI dataset that includes 812 young healthy adults. The dBEN was further clustered into 4 reoccurring BEN states by the k-means clustering method. The fraction window (FW) and mean dwell time (MDT) of one BEN state, characterized by the extremely low overall BEN, were found to be negatively correlated with general cognitive abilities (i.e., cognitive flexibility, inhibitory control, and processing speed). Another BEN state, characterized by intermediate overall BEN and low within-state BEN located in DMN, ECN, and part of SAN, its FW, and MDT were positively correlated with the above cognitive abilities. The results of our study advance our understanding of the underlying mechanism of BEN dynamics and provide a potential framework for future investigations in clinical populations.

3.
J Phys Chem Lett ; 15(17): 4679-4685, 2024 May 02.
Article in English | MEDLINE | ID: mdl-38656159

ABSTRACT

Determining the true or false chirality of a system is essential for the design of advanced chiral materials and for improving their applications. Typically, a magnetic field would cause false optical activity in the chiral material system, thus confusing the true chirality's influence. Here, we provide a simple way to uncover the true and false chirality in chiral ferrimagnetic nanoparticles (FNPs) by using the gel as a rigid frame. The remnant local magnetic field of the FNP gel can be easily adjusted by an external magnetic field or by controlling the concentration of the FNPs. Moreover, the potential application of the FNP gel is detected by induced magnetic circularly polarized luminescence. This work provides deep insight into the true and false chirality in magnetic nanosystems and offers a strategy to construct new optic elements with an adjustable local magnetic field.

4.
Bioconjug Chem ; 35(5): 665-673, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38598424

ABSTRACT

Enhancing the accumulation and retention of small-molecule probes in tumors is an important way to achieve accurate cancer diagnosis and therapy. Enzyme-stimulated macrocyclization of small molecules possesses great potential for enhanced positron emission tomography (PET) imaging of tumors. Herein, we reported an 18F-labeled radiotracer [18F]AlF-RSM for legumain detection in vivo. The tracer was prepared by a one-step aluminum-fluoride-restrained complexing agent ([18F]AlF-RESCA) method with high radiochemical yield (RCY) (88.35 ± 3.93%) and radiochemical purity (RCP) (>95%). More notably, the tracer can be transformed into a hydrophobic macrocyclic molecule under the joint action of legumain and reductant. Simultaneously, the tracer could target legumain-positive tumors and enhance accumulation and retention in tumors, resulting in the amplification of PET imaging signals. The enhancement of radioactivity enables PET imaging of legumain activity with high specificity. We envision that, by combining this highly efficient 18F-labeled strategy with our intramolecular macrocyclization reaction, a range of radiofluorinated tracers can be designed for tumor PET imaging and early cancer diagnosis in the future.


Subject(s)
Cysteine Endopeptidases , Fluorine Radioisotopes , Positron-Emission Tomography , Positron-Emission Tomography/methods , Fluorine Radioisotopes/chemistry , Cysteine Endopeptidases/metabolism , Cysteine Endopeptidases/analysis , Animals , Cyclization , Mice , Humans , Radiopharmaceuticals/chemistry , Cell Line, Tumor , Mice, Inbred BALB C , Fluorides/chemistry , Mice, Nude
5.
Molecules ; 29(6)2024 Mar 12.
Article in English | MEDLINE | ID: mdl-38542890

ABSTRACT

An unparalleled copper(I)-catalyzed synthesis of 1,3,4-oxadiazoles from tertiary amines in one step has been described. The one-pot reactions involving (N-isocyanimine)triphenylphosphorane, tertiary amines, and carboxylic acids resulted in the formation of 1,3,4-oxadiazoles in moderate to good yields through a consecutive oxidative Ugi/aza-Wittig reaction, enabling the direct functionalization of sp3 C-H bonds adjacent to the nitrogen atom. This method offered several notable advantages, including ligands-free, exceptional productivity and a high functional group tolerance. The preliminary biological evaluation demonstrated that compound 4f inhibited hepatoma cells efficiently, suggesting potentially broad applications of the approach for synthesis and medicinal chemistry.


Subject(s)
Copper , Organophosphorus Compounds , Oxadiazoles , Copper/chemistry , Oxadiazoles/chemistry , Amines/chemistry , Catalysis , Oxidative Stress
6.
Vision Res ; 217: 108365, 2024 04.
Article in English | MEDLINE | ID: mdl-38368707

ABSTRACT

There has been much debate on whether color categories affect how we perceive color. Recent theories have put emphasis on the role of top-down influence on color perception that the original continuous color space in the visual cortex may be transformed into categorical encoding due to top-down modulation. To test the influence of color categories on color perception, we adopted an RSVP paradigm, where color stimuli were presented at a fast speed of 100 ms per stimulus and were forward and backward masked by the preceding and following stimuli. Moreover, no explicit color naming or categorization was required. In theory, backward masking with such a short interval in a passive viewing task should constrain top-down influence from higher-level brain areas. To measure any potentially subtle differences in brain response elicited by different color categories, we embedded a sensitive frequency-tagging-based EEG paradigm within the RSVP stimuli stream where the oddball color stimuli were encoded with a different frequency from the base color stimuli. We showed that EEG responses to cross-category oddball colors at the frequency where the oddball stimuli were presented was significantly larger than the responses to within-category oddball colors. Our study suggested that the visual cortex can automatically and implicitly encode color categories when color stimuli are presented rapidly.


Subject(s)
Color Perception , Visual Cortex , Humans , Color Perception/physiology , Brain/physiology , Visual Cortex/physiology , Electroencephalography , Color
7.
Mol Pharm ; 21(3): 1382-1389, 2024 Mar 04.
Article in English | MEDLINE | ID: mdl-38372213

ABSTRACT

Cathepsin B, a lysosomal protease, is considered as a crucial biomarker for tumor diagnosis and treatment as it is overexpressed in numerous cancers. A stimulus-responsive SF scaffold has been reported to detect the activity of a variety of tumor-associated enzymes. In this work, a small-molecule PET tracer ([68Ga]NOTA-SF-CV) was developed by combining an SF scaffold with a cathepsin B-specific recognition substrate Cit-Val. Upon activation by cathepsin B, [68Ga]NOTA-SF-CV could form the cyclization product in a reduction environment, resulting in reduced hydrophilicity. This unique property could effectively prevent exocytosis of the tracer in cathepsin B-overexpressing tumor cells, leading to prolonged retention and amplified PET imaging signal. Moreover, [68Ga]NOTA-SF-CV had great targeting specificity to cathepsin B. In vivo microPET imaging results showed that [68Ga]NOTA-SF-CV was able to effectively visualize the expression level of cathepsin B in various tumors. Hence, [68Ga]NOTA-SF-CV may be served as a potential tracer for diagnosing cathepsin B-related diseases.


Subject(s)
Gallium Radioisotopes , Neoplasms , Humans , Gallium Radioisotopes/chemistry , Cathepsin B , Positron-Emission Tomography/methods , Neoplasms/diagnostic imaging , Radiopharmaceuticals/chemistry , Cell Line, Tumor
8.
Abdom Radiol (NY) ; 49(5): 1444-1455, 2024 05.
Article in English | MEDLINE | ID: mdl-38265452

ABSTRACT

PURPOSE: Microvascular invasion (MVI) is a critical factor in predicting the recurrence and prognosis of hepatocellular carcinoma (HCC) after liver transplantation (LT). However, there is a lack of reliable preoperative predictors for MVI. The purpose of this study is to evaluate the potential of an 18F-FDG PET/CT-based nomogram in predicting MVI before LT for HCC. METHODS: 83 HCC patients who obtained 18F-FDG PET/CT before LT were included in this retrospective research. To determine the parameters connected to MVI and to create a nomogram for MVI prediction, respectively, Logistic and Cox regression models were applied. Analyses of the calibration curve and receiver operating characteristic (ROC) curves were used to assess the model's capability to differentiate between clinical factors and metabolic data from PET/CT images. RESULTS: Among the 83 patients analyzed, 41% were diagnosed with histologic MVI. Multivariate logistic regression analysis revealed that Child-Pugh stage, alpha-fetoprotein, number of tumors, CT Dmax, and Tumor-to-normal liver uptake ratio (TLR) were significant predictors of MVI. A nomogram was constructed using these predictors, which demonstrated strong calibration with a close agreement between predicted and actual MVI probabilities. The nomogram also showed excellent differentiation with an AUC of 0.965 (95% CI 0.925-1.000). CONCLUSION: The nomogram based on 18F-FDG PET/CT metabolic characteristics is a reliable preoperative imaging biomarker for predicting MVI in HCC patients before undergoing LT. It has demonstrated excellent efficacy and high clinical applicability.


Subject(s)
Carcinoma, Hepatocellular , Fluorodeoxyglucose F18 , Liver Neoplasms , Liver Transplantation , Neoplasm Invasiveness , Nomograms , Positron Emission Tomography Computed Tomography , Radiopharmaceuticals , Humans , Carcinoma, Hepatocellular/diagnostic imaging , Carcinoma, Hepatocellular/pathology , Carcinoma, Hepatocellular/surgery , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/pathology , Liver Neoplasms/surgery , Male , Positron Emission Tomography Computed Tomography/methods , Female , Middle Aged , Retrospective Studies , Radiopharmaceuticals/pharmacokinetics , Aged , Adult , Microvessels/diagnostic imaging , Predictive Value of Tests
9.
Small ; : e2311639, 2024 Jan 10.
Article in English | MEDLINE | ID: mdl-38204283

ABSTRACT

The development of ultraviolet circularly polarized light (UVCPL) sources has the potential to benefit plenty of practical applications but remains a challenge due to limitations in available material systems and a limited understanding of the excited state chirality transfer. Herein, by constructing hybrid structures of the chiral perovskite CsPbBr3 nanoplatelets and organic molecules, excited state chirality transfer is achieved, either via direct binding or triplet energy transfer, leading to efficient UVCPL emission. The underlying photophysical mechanisms of these two scenarios are clarified by comprehensive optical studies. Intriguingly, UVCPL realized via the triple energy transfer, followed by the triplet-triplet annihilation upconversion processes, demonstrates a 50-fold enhanced dissymmetry factor glum . Furthermore, stereoselective photopolymerization of diacetylene monomer is demonstrated by using such efficient UVCPL. This study provides both novel insights and a practical approach for realizing UVCPL, which can also be extended to other material systems and spectral regions, such as visible and near-infrared.

10.
Sci Total Environ ; 914: 169664, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38163612

ABSTRACT

The atmospheric oxidation capacity (AOC) reflects the removal rate of atmospheric pollutants, and this index is typically characterized by the oxidant concentration or total reaction rate. The AOC plays a crucial role in the formation of atmospheric particulate matters and serves as an important indicator for studying changes in the concentration. In this study, we analyse the characteristics of atmospheric oxidants in Lanzhou based on data in the year of 2020 and 2021 retrieved from the Atmospheric Comprehensive Observation Station in Lanzhou. Empirical equations are applied to estimate the impact of atmospheric oxidative properties secondary generation concentrations of atmospheric particulate matters with different particle sizes. The results indicate that the annual average values of Ox were 146 µg/m3 in 2020 and 139 µg/m3 in 2021. The AOC was the highest in summer and lowest in winter. The correlation coefficient between O3 and Ox was significantly higher than that between NO2 and Ox, suggesting that O3 exerted a greater impact on the AOC in Lanzhou. A low AOC (MDA8 O3 ≤ 100 µg/m3) promoted the oxidation process of VOCs and other precursors, leading to the generation of secondary aerosols and subsequent formation of secondary particles. There were negative correlations between Ox and atmospheric particulate matters, secondary inorganic components, sulfur oxidation ratio (SOR) and nitrogen oxidation ratio (NOR), indicating that excessively high levels of Ox could inhibit the conversion rate of SO2 and NO2 into their respective forms to a certain extent.

11.
Nat Commun ; 15(1): 139, 2024 Jan 02.
Article in English | MEDLINE | ID: mdl-38167785

ABSTRACT

Assembly ubiquitously occurs in nature and gives birth to numerous functional biomaterials and sophisticated organisms. In this work, chiral hydrogen-bonded organic-inorganic frameworks (HOIFs) are synthesized via biomimicking the self-assembly process from amino acids to proteins. Enjoying the homohelical configurations analogous to α-helix, the HOIFs exhibit remarkable chiroptical activity including the chiral fluorescence (glum = 1.7 × 10-3) that is untouched among the previously reported hydrogen-bonded frameworks. Benefitting from the dynamic feature of hydrogen bonding, HOIFs enable enantio-discrimination of chiral aliphatic substrates with imperceivable steric discrepancy based on fluorescent change. Moreover, the disassembled HOIFs after recognition applications are capable of being facilely regenerated and self-purified via aprotic solvent-induced reassembly, leading to at least three consecutive cycles without losing the enantioselectivity. The underlying mechanism of chirality bias is decoded by the experimental isothermal titration calorimetry together with theoretic simulation.

12.
Small ; 20(15): e2306810, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38012531

ABSTRACT

Pearlescent materials are of technological importance in a diverse array of industries from cosmetics to premium paints; however, chiral pearlescent materials remain unexplored. Here, chiral pearlescent films with on-demand iridescence and metallic appearance are simply organized by leveraging vertical pressure to direct the self-assembly of cellulose nanocrystals. The films are formed with a bilayer planar anchored left-handed chiral nematic architecture, in which the bottom layer is featured with a vertical gradient pitch, and the top layer is featured with a uniform pitch. Simultaneous reflection of the rainbow colors and an on-demand color of left-handed polarized light with angle-dependent wavelength and polarization state accounts for the unique optical phenomenon based on experimental observation and theoretical analysis. Such chiroptical property can be readily tuned with architectural design, enabling reproducible optical appearance with high fidelity. Bringing the pearlescence, iridescence, and specular reflection together endows cellulose nanocrystal films with rich and tunable chiroptical properties that can be used for anti-counterfeiting applications. The current work marks the beginning of chiral pearlescent materials from renewable resources, while the pressure-directed self-assembly provides a step toward scalable production.

13.
J Environ Manage ; 351: 119864, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38109823

ABSTRACT

It is well accepted that tidal wetland vegetation performs a significant amount of water filtration for wetlands. However, there is currently little information on how various wetland plants remove nitrogen (N) and phosphorus (P) and how they differ in their denitrification processes. This study compared and investigated the denitrification and phosphorus removal effects of three typical wetland plants in the Yangtze River estuary wetland (Phragmites australis, Spartina alterniflora, and Scirpus mariqueter), as well as their relevant mechanisms, using an experimental laboratory-scale horizontal subsurface flow constructed wetland (CW). The results showed that all treatment groups with plants significantly reduced N pollutants as compared to the control group without plants. In comparison to S. mariqueter (77.2-83.2%), S. alterniflora and P. australis had a similar total nitrogen (TN)removal effectiveness of nearly 95%. With a removal effectiveness of over 99% for ammonium nitrogen (NH4+-N), P. australis outperformed S. alterniflora (95.6-96.8%) and S. mariqueter (94.6-96.5%). The removal of nitrite nitrogen (NO2--N)and nitrate nitrogen (NO3--N)from wastewater was significantly enhanced by S. alterniflora compared to the other treatment groups. Across all treatment groups, the removal rate of PO43--P was greater than 95%. P. australis and S. alterniflora considerably enriched more 15N than S. mariqueter, according to the results of the 15N isotope labeling experiment. While the rhizosphere and bulk sediments of S. alterniflora were enriched with more simultaneous desulfurization-denitrification bacterial genera (such as Paracoccus, Sulfurovum, and Sulfurimonas), which have denitrification functions, the rhizosphere and bulk sediments of P. australis were enriched with more ammonia-oxidizing archaea and ammonia-oxidizing bacteria. As a result, compared to the other plants, P. australis and S. alterniflora demonstrate substantially more significant ability to remove NH4+-N and NO2--N/NO3--N from simulated domestic wastewater.


Subject(s)
Nitrogen , Wetlands , Nitrogen/analysis , Phosphorus/analysis , Ammonia , Nitrogen Dioxide , Wastewater , Plants , Poaceae , China
14.
Mol Biomed ; 4(1): 43, 2023 Nov 27.
Article in English | MEDLINE | ID: mdl-38008847

ABSTRACT

Mesenchymal stem cells (MSCs) have been applied in transplantation to treat intracerebral hemorrhage (ICH) but with limited efficacy. Accumulated evidence has shown that glial cell-derived neurotrophic factor (GDNF) plays a crucial part in neuronal protection and functional recovery of the brain after ICH; however, GDNF has difficulty crossing the blood-brain barrier, which limits its application. In this study, we investigated the influences of MSCs overexpressing GDNF (MSCs/GDNF) on the brain structure as well as gait of rats after ICH and explored the possible mechanisms. We found that cell transplantation could reverse the neurological dysfunction and brain damage caused by ICH to a certain extent, and MSCs/GDNF transplantation was superior to MSCs transplantation. Moreover, Transplantation of MSCs overexpressing GDNF effectively reduced the volume of bleeding foci and increased the level of glucose uptake in rats with ICH, which could be related to improving mitochondrial quality. Furthermore, GDNF produced by transplanted MSCs/GDNF further inhibited neuroinflammation, improved mitochondrial quality and function, promoted angiogenesis and the survival of neurons and oligodendrocytes, and enhanced synaptic plasticity in ICH rats when compared with simple MSC transplantation. Overall, our data indicate that GDNF overexpression heightens the curative effect of MSC implantation in treating rats following ICH.

15.
Front Psychol ; 14: 1290342, 2023.
Article in English | MEDLINE | ID: mdl-38022946

ABSTRACT

The research creativity of doctoral students is not solely fueled by their intrinsic motivation, but also thrives in an environment that offers challenging research opportunities, substantial support, and feedback from significant others. Based on the job demands-resources model, this study aims to explore the impact of challenge research stressors on the research creativity of Chinese doctoral students. A mediated moderation model was constructed to examine the mediating effect of achievement motivation and the moderating effect of supervisor developmental feedback on the relationship between challenge research stressors and research creativity. A total of 538 valid questionnaires were collected from doctoral students using convenience sampling and snowball sampling. The questionnaires included the Challenge Research Stressors Scale, the Research Creativity Scale, the Achievement Motivation Scale, and the Supervisor Developmental Feedback Scale. Regression analyses, bootstrap testing, and simple slope analyses were used to estimate the various relationships. The findings indicated that challenge research stressors had a positive effect on doctoral students' research creativity. Supervisor developmental feedback positively moderated the impact of challenge research stressors on the achievement motivation and research creativity of doctoral students. Achievement motivation partially mediated the influence of challenge research stressors on doctoral students' research creativity, and further fully mediated the interaction effect of challenge research stressors and supervisor developmental feedback on doctoral students' research creativity. These findings contribute not only to our understanding of the mechanisms and boundary conditions through which challenge research stressors impact the research creativity of doctoral students, but also provide valuable insights into how to stimulate and maintain their research creativity.

16.
PLoS One ; 18(10): e0293043, 2023.
Article in English | MEDLINE | ID: mdl-37856510

ABSTRACT

Podocyte injury plays a key role in the production of proteinuria and is closely related to the progression of chronic kidney disease (CKD). Alleviating podocyte injury is beneficial to prevent the occurrence and development of CKD. tRNA-derived RNA fragments (tRFs) are associated with podocytes injury processes such as protein binding, cell adhesion, synapses, the actin cytoskeleton. Our previous data showed that tRF-003634 tightly correlated with podocyte injury, while its effect remains unclear. This study aimed to investigate the role of tRF-003634 in podocyte injury and the potential mechanisms. The expression level of tRF-003634, nephrin, podocin and tRF-003634 targeted toll-like receptor 4 (TLR4) in podocytes and kidney tissues were examined by quantitative real-time PCR (qRT-PCR), western blot and immunohistochemistry. The biochemical indices were monitored and renal pathological changes were assessed by hematoxylin and eosin PAS staining. Furthermore, potential target genes of tRF-003634 were screened using high-throughput mRNA sequencing, and then confirmed by RNA pulse-chase analysis. The results showed that tRF-003634 was downregulated in adriamycin (Adr)-induced podocyte injury. Overexpression of tRF-003634 increased the expression of nephrin and podocin in vivo and in vitro and alleviated podocyte injury. Meanwhile, overexpression of tRF-003634 alleviated proteinuria and renal pathological damage. In addition, high-throughput sequencing after overexpression of tRF-003634 showed that TLR4 might be a downstream target gene. tRF-003634 can alleviate podocyte injury by reducing the stability of TLR4 mRNA, possibly by competing with TLR4 mRNA to bind to YTH domain-containing protein 1 (YTHDC1). In conclusion, tRF-003634 was underexpressed in Adr-induced podocyte injury, and its overexpression alleviated podocyte injury in vitro and in vivo by reducing the stability of TLR4 mRNA.


Subject(s)
Podocytes , Renal Insufficiency, Chronic , Doxorubicin/adverse effects , Doxorubicin/metabolism , Podocytes/metabolism , Proteinuria/pathology , Renal Insufficiency, Chronic/pathology , RNA, Messenger/metabolism , Toll-Like Receptor 4/genetics , Toll-Like Receptor 4/metabolism
17.
Molecules ; 28(20)2023 Oct 19.
Article in English | MEDLINE | ID: mdl-37894663

ABSTRACT

For the first time, a novel dithiomaleimides (DTM) based tetra-antennary GalNAc conjugate was developed, which enable both efficient siRNA delivery and good traceability, without incorporating extra fluorophores. This conjugate can be readily constructed by three click-type reactions, that is, amidations, thiol-dibromomaleimide addition and copper catalyzed azide-alkyne cycloaddition (CuAAC). And it also has comparable siRNA delivery efficiency, with a GalNAc L96 standard to mTTR target. Additionally, due to the internal DTMs, a highly fluorescent emission was observed, which benefited delivery tracking and reduced the cost and side effects of the extra addition of hydrophobic dye molecules. In all, the simple incorporation of DTMs to the GalNAc conjugate structure has potential in gene therapy and tracking applications.


Subject(s)
Click Chemistry , Fluorescent Dyes , RNA, Small Interfering/genetics , Alkynes/chemistry , Azides/chemistry , Copper/chemistry , Cycloaddition Reaction , Catalysis
18.
Adv Mater ; 35(49): e2308198, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37721365

ABSTRACT

The chemical, physical and biological effects of chiral nanomaterials have inspired general interest and demonstrated important advantages in fundamental science. Here, chiral iron oxide supraparticles (Fe3 O4 SPs) modified by chiral penicillamine (Pen) molecules with g-factor of ≈2 × 10-3 at 415 nm are fabricated, and these SPs act as high-quality magnetic resonance imaging (MRI) contrast agents. Therein, the transverse relaxation efficiency and T2 -MRI results demonstrated chiral Fe3 O4 SPs have a r2 relaxivity of 157.39 ± 2.34 mM-1 ·S-1 for D-Fe3 O4 SPs and 136.21 ± 1.26 mM-1 ·S-1 for L-Fe3 O4 SPs due to enhanced electronic transition dipole moment for D-Fe3 O4 SPs compared with L-Fe3 O4 SPs. The in vivo MRI results show that D-Fe3 O4 SPs exhibit two-fold lower contrast ratio than L-Fe3 O4 SPs, which enhances targeted enrichment in tumor tissue, such as prostate cancer, melanoma and brain glioma tumors. Notably, it is found that D-Fe3 O4 SPs have 7.7-fold higher affinity for the tumor cell surface receptor cluster-of-differentiation 47 (CD47) than L-Fe3 O4 SPs. These findings uncover that chiral Fe3 O4 SPs act as a highly effective MRI contrast agent for targeting and imaging broad tumors, thus accelerating the practical application of chiral nanomaterials and deepening the understanding of chirality in biological and non-biological environments.


Subject(s)
Brain Neoplasms , Glioma , Male , Humans , Ferric Compounds , Contrast Media , Glioma/diagnostic imaging , Magnetic Resonance Imaging/methods
19.
Invest Ophthalmol Vis Sci ; 64(11): 1, 2023 08 01.
Article in English | MEDLINE | ID: mdl-37526617

ABSTRACT

Purpose: To probe the dynamic alternations of neural networks in real-time visual processing after visual deprivation (VD) removal. Methods: A prospective cross-sectional study was conducted. Twenty children with a history of early binocular VD caused by congenital cataracts and 20 matched typically developing (TD) children were enrolled. The event-related potential (ERP) data were obtained via high-density electroencephalography. ERP data were analyzed based on three components (P1, N170, and P2), three test conditions (objects, human faces, and Chinese characters), and peak time and region of interest (ROI) chosen on a grand average head map collapsed from the averaged waveform of each group. Source localization and alpha power spectrum density were applied to define the functional pattern of brain areas and evaluate the attention function. Results: The VD group showed significantly lower P1 amplitudes than the TD group under all conditions in peak ROIs, which were situated in the left occipito-temporal region. For both VD and TD groups, there were strong N170 effects in the character and human face conditions in the component's peak ROIs. Furthermore, source mapping indicated that the VD group generally showed significantly lower activation in the visual cortex and ventral stream, whereas the beyond network areas (mostly frontal areas) intensively participated in functional compensation in the VD group. The VD group showed significant poststimulus alpha desynchronization in object recognition. Conclusions: Our research described the mechanisms of visual networks after early binocular VD removal. Our findings may provide a new basis for the poor visual recovery after early binocular VD removal and offer clues for visual recovery strategies.


Subject(s)
Face , Pattern Recognition, Visual , Child , Humans , Pattern Recognition, Visual/physiology , Cross-Sectional Studies , Prospective Studies , Photic Stimulation , Electroencephalography , Brain Mapping
20.
Front Psychol ; 14: 1106066, 2023.
Article in English | MEDLINE | ID: mdl-37519394

ABSTRACT

Increasingly, higher education institutions are giving more attention to the language proficiency of non-native English-speaking teachers (NNESTs) due to their growing numbers. Despite a recent surge in the literature on NNESTs in the global discourse of English language teaching (ELT), the impacts of NNESTs' language competency within the higher education systems of their countries remain woefully under-examined. Of particular concern is the absence of students' voices. Therefore, this study explores higher education students' perception of NNESTs' language proficiency. Data was collected through class observations of five NNESTs and followed-up semi-structured interviews with five student focus groups recruited randomly from each class. Our results show that while students concur that NNESTs' language proficiency contributes to their learning performance in class, other factors (e.g., the teacher's effective teaching style and charming personality, relaxed class atmosphere, the difficulty level of the teaching materials, and the learners' proficiency level) also perceived to play key roles in boosting students' class learning effectiveness. The findings highlight the need to include students in the design of teaching approaches, course design, and curricula, as well as the reflection process about NNESTs' language proficiency.

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