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1.
Oncoimmunology ; 10(1): 1983306, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34595061

RESUMO

T cell-engaging therapies involving bispecific T cell engager (BiTE) and chimeric antigen receptor T (CAR-T) cells have achieved great success in the treatment of hematological tumors. However, the paucity of ideal cell surface molecules that can be targeted on glioblastoma (GBM) partially reduces the immunotherapeutic efficacy. Recently, high expression of Fn14 has been reported in several solid tumors, so the strategy of exploiting this specific antigen for GBM immunotherapy is worth studying. Consequently, we constructed Fn14× CD3 BiTE and Fn14-specific CAR-T cells and investigated their cytotoxic activity against GBM in vitro and in vivo. First, expression of Fn14 was confirmed in glioma tissues and GBM cells. Then, we designed Fn14-specific BiTE and CAR-T cells and tested their cytotoxicity in GBM cell cultures and mouse models of GBM. Fn14 was highly expressed in GBM tissues and cell lines, while it was undetectable in normal brain samples. Fn14× CD3 BiTE, Fn14 CAR-T cells and Fn14 CAR-T/IL-15 cells were antigen-specific and highly cytotoxic, showing good antitumor activity in vitro and causing significant regression of established solid tumors in xenograft models. However, the xenografts treated with Fn14 CAR-T cells regrew, whereas xenografts treated with Fn14 CAR-T/IL-15 cells did not. IL-15 engineering augmented the antitumor activity of Fn14 CAR-T cells and resulted in significant antitumor effects similar to those of Fn14× CD3 BiTE. Our results suggest that Fn14 is an appropriate target for GBM. Anti-Fn14 BiTE and Fn14-specific CAR-T/IL-15 cells may be exciting immunotherapeutic options for malignant brain cancer.

2.
Front Immunol ; 12: 723885, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34566982

RESUMO

Eukaryotic translation initiation factor 4B (eIF4B) plays an important role in mRNA translation initiation, cell survival and proliferation in vitro. However, its function in vivo is poorly understood. Here, we identified that eIF4B knockout (KO) in mice led to embryonic lethality, and the embryos displayed severe liver damage. Conditional KO (CKO) of eIF4B in adulthood profoundly increased the mortality of mice, characterized by severe pathological changes in several organs and reduced number of peripheral blood lymphocytes. Strikingly, eIF4B CKO mice were highly susceptible to viral infection with severe pulmonary inflammation. Selective deletion of eIF4B in lung epithelium also markedly promoted replication of influenza A virus (IAV) in the lung of infected animals. Furthermore, we observed that eIF4B deficiency significantly enhanced the expression of several important inflammation-associated factors and chemokines, including serum amyloid A1 (Saa1), Marco, Cxcr1, Ccl6, Ccl8, Ccl20, Cxcl2, Cxcl17 that are implicated in recruitment and activation of neutrophiles and macrophages. Moreover, the eIF4B-deficient mice exhibited impaired natural killer (NK) cell-mediated cytotoxicity during the IAV infection. Collectively, the results reveal that eIF4B is essential for mouse survival and host antiviral responses, and establish previously uncharacterized roles for eIF4B in regulating normal animal development and antiviral immunity in vivo.

3.
Virulence ; 12(1): 2443-2460, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34517783

RESUMO

A growing body of evidence suggests the pivotal role of long non-coding RNA (lncRNA) in influenza virus infection. Based on next-generation sequencing, we previously demonstrated that Lnc45 was distinctively stimulated by H5N1 influenza virus in mice. In this study, we systematically investigated the specific role of Lnc45 during influenza A virus (IAV) infection. Through qRT-PCR, we first demonstrated that Lnc45 is highly up-regulated by different subtypes of IAV strains, including H5N1, H7N9, and H1N1 viruses. Using RNA-FISH and qRT-PCR, we then found that Lnc45 can translocate from nuclear to cytoplasm during H5N1 virus infection. In addition, forced Lnc45 expression dramatically impeded viral replication of H1N1, H5N1, and H7N9 virus, while abolish of Lnc45 expression by RNA interference favored replication of these viruses, highlighting the potential broad antiviral activity of Lnc45 to IAV. Correspondingly, overexpression of Lnc45 inhibited viral polymerase activity and suppressed IAV-induced cell apoptosis. Moreover, Lnc45 significantly restrained nuclear aggregation of viral NP and PA proteins during H5N1 virus infection. Further functional study revealed that the stem ring arms of Lnc45 mainly mediated the antiviral effect. Therefore, we here demonstrated that Lnc45 functions as a broad-spectrum antiviral factor to inhibit influenza virus replication probably through inhibiting polymerase activity and NP and PA nuclear accumulation via its stem ring arms. Our study not only advances our understanding of the complexity of the IAV pathogenesis but also lays the foundation for developing novel anti-IAV therapeutics targeting the host lncRNA.

4.
Signal Transduct Target Ther ; 6(1): 331, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-34471099

RESUMO

The recently emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the causative agent of ongoing global pandemic of COVID-19, may trigger immunosuppression in the early stage and overactive immune response in the late stage of infection; However, the underlying mechanisms are not well understood. Here we demonstrated that the SARS-CoV-2 nucleocapsid (N) protein dually regulated innate immune responses, i.e., the low-dose N protein suppressed type I interferon (IFN-I) signaling and inflammatory cytokines, whereas high-dose N protein promoted IFN-I signaling and inflammatory cytokines. Mechanistically, the SARS-CoV-2 N protein dually regulated the phosphorylation and nuclear translocation of IRF3, STAT1, and STAT2. Additionally, low-dose N protein combined with TRIM25 could suppress the ubiquitination and activation of retinoic acid-inducible gene I (RIG-I). Our findings revealed a regulatory mechanism of innate immune responses by the SARS-CoV-2 N protein, which would contribute to understanding the pathogenesis of SARS-CoV-2 and other SARS-like coronaviruses, and development of more effective strategies for controlling COVID-19.


Assuntos
COVID-19/imunologia , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Imunidade Inata , SARS-CoV-2/imunologia , Transdução de Sinais/imunologia , Células A549 , COVID-19/patologia , Células CACO-2 , Células HEK293 , Células Hep G2 , Humanos , Interferon Tipo I/imunologia , Fosfoproteínas/imunologia
5.
Sci Total Environ ; 798: 149277, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34340074

RESUMO

Understanding the historical and future changing characteristics of key climatic variables and runoff in 10 major river zones in China is essential for water resources evaluation and management. To this end, the historical and future changing trends of key hydrometeorological variables, including precipitation, potential evapotranspiration, and runoff were analyzed in detail for each water zone across China. The climate elasticity method was also established to quantify the impacts of climate change and human activities on historical runoff variations. The results indicate that the characteristics and causes of runoff variations in China were generally spatially heterogeneous. The runoff in water-scarce river basins of northern China decreased significantly during the period of 1961-2018, variations of which were more sensitive to human activities. For southern water zones in China, the runoff showed no significant trend and climate change was the main influencing factor. On basis of 9 Coupled Model Intercomparison Project Phase 6 (CMIP6) climate model ensemble simulations under three different shared socioeconomic pathways (ssp126, ssp245 and ssp585), the future runoff in 10 typical basins of the water zones were projected and the results suggested an increasing trend of runoff over China, thanks to increasing precipitation in the rest 21 century. While under ssp585, the rising air temperature tends to evaporate more water and offset the effect of precipitation increase to some extent, resulting in that the increments of runoff under ssp585 are not necessarily greater than those under ssp245 and ssp126. Overall, our study could be used as a basis to support climate adaptation strategies and policies to cope with future water resources conditions.


Assuntos
Rios , Água , China , Mudança Climática , Humanos , Movimentos da Água
6.
Artigo em Inglês | MEDLINE | ID: mdl-34448329

RESUMO

The longevity and reusability of N95-grade filtering facepiece respirators (N95 FFRs) are limited by consecutive donning and disinfection treatments. Herein, we developed stable N97 nanofibrous respirators based on chemically modified surface to enable remarkable filtration characteristics via polarity driven interaction. This was achieved by a thin-film coated polyacrylonitrile nanofibrous membrane (TFPNM), giving an overall long-lasting filtration performance with high quality factor at 0.42 Pa-1 (filtration efficiency: over 97 %; pressure drop: around 10 Pa), which is higher than that of the commercial N95 FFRs (0.10-0.41 Pa-1 ) tested with a flow rate of 5 L min-1 and the 0.26 µm NaCl aerosol. A coxsackie B4 virus filtration test demonstrated that TFPNM also had strong virus capture capacity of 97.67 %. As compared with N95 FFRs, the TFPNM was more resistant to a wider variety of disinfection protocols, and the overall filtration characteristics remained N97 standard.

7.
Radiology ; 301(1): 178-184, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34282966

RESUMO

Background Resting-state functional MRI (rs-fMRI) is a potential alternative to task-based functional MRI (tb-fMRI) for somatomotor network (SMN) identification. Brain networks can also be generated from tb-fMRI by using independent component analysis (ICA). Purpose To investigate whether the SMN can be identified by using ICA from a language task without a motor component, the sentence completion functional MRI (sc-fMRI) task, compared with rs-fMRI. Materials and Methods The sc-fMRI and rs-fMRI scans in patients who underwent presurgical brain mapping between 2012 and 2016 were analyzed, using the same imaging parameters (other than scanning time) on a 3.0-T MRI scanner. ICA was performed on rs-fMRI and sc-fMRI scans with use of a tool to separate data sets into their spatial and temporal components. Two neuroradiologists independently determined the presence of the dorsal SMN (dSMN) and ventral SMN (vSMN) on each study. Groups were compared by using t tests, and logistic regression was performed to identify predictors of the presence of SMNs. Results One hundred patients (mean age, 40.9 years ± 14.8 [standard deviation]; 61 men) were evaluated. The dSMN and vSMN were identified in 86% (86 of 100) and 76% (76 of 100) of rs-fMRI scans and 85% (85 of 100) and 69% (69 of 100) of sc-fMRI scans, respectively. The concordance between rs-fMRI and sc-fMRI for presence of dSMN and vSMN was 75% (75 of 100 patients) and 53% (53 of 100 patients), respectively. In 10 of 14 patients (71%) where rs-fMRI did not show the dSMN, sc-fMRI demonstrated it. This rate was 67% for the vSMN (16 of 24 patients). Conclusion In the majority of patients, independent component analysis of sentence completion task functional MRI scans reliably demonstrated the somatomotor network compared with resting-state functional MRI scans. Identifying target networks with a single sentence completion scan could reduce overall functional MRI scanning times by eliminating the need for separate motor tasks. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Field and Birn in this issue.


Assuntos
Mapeamento Encefálico/métodos , Neoplasias Encefálicas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Córtex Motor/diagnóstico por imagem , Adulto , Encéfalo/diagnóstico por imagem , Feminino , Humanos , Idioma , Masculino , Reprodutibilidade dos Testes , Descanso
9.
Infect Genet Evol ; 93: 104993, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34242774

RESUMO

Avian influenza virus (AIV) H7N9 that emerged in 2013 in eastern China is a novel zoonotic agent mainly circulating in poultry without clinical signs but causing severe disease with high fatality in humans in more than 5 waves. Since the emergence of highly pathogenic (HP) H7N9 variants in 2016, it has induced heavy losses in the poultry industry leading to the implementation of an intensive nationwide vaccination program at the end of wave 5 (September 2017). To characterize the ongoing evolution of H7N9 AIV, we conducted analyses of H7N9 glycoprotein genes obtained from 2013 to 2019. Bayesian analyses revealed a decreasing population size of HP H7N9 variants post wave 5. Phylogenetic topologies revealed that two novel small subclades were formed and carried several fixed amino acid mutations that were along HA and NA phylogenetic trees since wave 5. Some of the mutations were located at antigenic sites or receptor binding sites. The antigenic analysis may reveal a significant antigenic drift evaluated by hemagglutinin inhibition (HI) assay and the antigenicity of H7N9 AIV might evolute in large leaps in wave 7. Molecular simulations found that the mutations (V135T, S145P, and L226Q) around the HA receptor pocket increased the affinity to α2,3-linked sialic acid (SIA) while decreased to α2,6-linked SIA. Altered affinity may suggest that HP H7N9 variations aggravate the pathogenicity to poultry but lessen the threat to public health. Selection analyses showed that the HP H7N9 AIV experienced an increasing selection pressure since wave 5, and the national implementation of vaccination might intensify the role of natural selection during the evolution waves 6 and 7. In summary, our data provide important insights about the genetic and antigenic diversity of circulating HP H7N9 viruses from 2017 to 2019. Enhanced surveillance is urgently warranted to understand the current situation of HP H7N9 AIV.

10.
Food Funct ; 12(17): 7664-7675, 2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34236362

RESUMO

The aim of this study was to investigate the immunomodulatory effect and mechanism of the glycopeptides from Paecilomyces sinensis (CPS-II) on ethanol induced ulcers in mice. In this study, histopathological evaluation (H&E staining) and the gastric ulcer score, ulcer index, total acid secretion and gastric pH value were used to determine the anti-ulcer activity. The expression levels of interleukin (IL)-6, interleukin (IL)-10 and tumor necrosis factor-α (TNF-α) were detected by ELISA. The contents of superoxide dismutase (SOD), malondialdehyde (MDA) and epidermal growth factor (PEG2) in serum were measured according to the instructions for the reagents. Western blotting was used to detect the effect of CPS-II on the MEK/ERK pathway. The results showed that CPS-II could inhibit the ulcer score and ulcer index compared with the disease control group. CPS-II could significantly increase gastric pH and decrease gastric acid secretion in mice. The ELISA analysis showed that the expression levels of IL-6 and TNF-α in the CPS-II treatment group were significantly decreased, while the expression levels of IL-10 were significantly increased in the CPS-II treatment group. In the resveratrol treatment group, the content of MDA in serum was decreased, and the level of PEG2 and the activity of SOD in serum were significantly increased, which indicated that CPS-II has immunoregulation and anti-ulcer properties. The CPS-II treatment group could reduce the expression level of miR-9-5p in gastric tissue. pEGFR had been identified as a potential target of miR-9-5p. Western blot analysis showed that CPS-II could up-regulate the relative protein expression of pEGFR/EGFR, pRaf/Raf, pMEK/MEK, pERK/ERK, and ZO-1. The results showed that CPS-II could reduce oxidative stress and inflammatory response by regulating the miR-9-5p-MEK/ERK signaling pathway, thus protecting the gastric mucosa and improving stress gastric ulcers.

11.
Bioengineered ; 12(1): 2906-2914, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34167441

RESUMO

MicroRNAs (miRNAs) play a very important role in the development of acute myeloid leukemia (AML). This study focuses on the effects of miR-9 on the regulation of AML cells and their related signaling pathways. We found that the expression of miR-9 was significantly decreased in four AML cell lines (THP-1, HL-60, TF-1 and KG-1) compared with the human normal bone marrow cells (HS-5). Moreover, miR-9 overexpression inhibited HL-60 cell proliferation ability, and promoted apoptosis. However, interfering with miR-9 expression promoted the proliferation of HL-6 cells and inhibited apoptosis. Western blotting results subsequently showed that overexpression of miR-9 could elevate the expression of MAT1, LATS1, and LATS2 in HL-60 cells, and inhibit the expression of YAP, while the interference with miR-9 had the opposite result. Taken together, miR-9 may act as a tumor suppressor by activating the Hippo/YAP signaling pathway of AML cells, which in this way supply ideas for the clinical remedy of AML patients.

12.
Environ Sci Pollut Res Int ; 28(39): 55700-55715, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34137010

RESUMO

To reduce losses from the various disasters, regional water security evaluation and risk control model is studied. The model is built upon different kinds of indices in water security system, proceeding from the whole structure and its parts of evaluation, forewarning and decision making analysis. Based on China's national conditions, this study firstly advances an evaluation index system of regional water security, which includes three subsystems of water resource security, water environment security, and water disaster control security. Secondly, fuzzy analytic hierarchy process based on accelerating genetic algorithm (AGA-FAHP) combines with entropy weight method (EW) to determine the objective weights of evaluation indexes. The subjective and objective weights can be integrated by the principle of minimum relative information entropy. The subsystem weights are obtained by using AGA-FAHP. Then regional water security evaluation model is established. Thirdly, the comparison judging method is adopted to divide warning degree of water security with the comprehensive evaluation index and forewarning standards, and then the local conditions for proposing planning schemes. Finally, decision making analysis is employed to find the effective indices based on projection pursuit technique with the ideal point method in multi-index decision. This study takes Jiangsu province, China as an example. The evaluation results from 2000 to 2015 show that the development trend of water security is increasing on the whole except in several individual years. Risk forewarning doesn't take place in recent years. But risk is always there. So, project and non-project measures are proposed for the corresponding forewarning levels. From light warnings for three times and moderate warning for once in 2000, 2001, 2002, and 2004, index 1, 3, 4, 11, 13, 17, and 18 are selected as the effective indices to decision making analysis in common. Then, the solution schemes are given as the processing method accordingly. This conclusion is reasonable and its method is practical that match the reality. It suggests that the presented model is feasible with theory and application, which can offer advice in regional water security management to some extent.


Assuntos
Abastecimento de Água , Água , China
14.
Nano Lett ; 2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34086471

RESUMO

Detection of AC magnetic fields at the nanoscale is critical in applications ranging from fundamental physics to materials science. Isolated quantum spin defects, such as the nitrogen-vacancy center in diamond, can achieve the desired spatial resolution with high sensitivity. Still, vector AC magnetometry currently relies on using different orientations of an ensemble of sensors, with degraded spatial resolution, and a protocol based on a single NV is lacking. Here we propose and experimentally demonstrate a protocol that exploits a single NV to reconstruct the vectorial components of an AC magnetic field by tuning a continuous driving to distinct resonance conditions. We map the spatial distribution of an AC field generated by a copper wire on the surface of the diamond. The proposed protocol combines high sensitivity, broad dynamic range, and sensitivity to both coherent and stochastic signals, with broad applications in condensed matter physics, such as probing spin fluctuations.

15.
Brain Res Bull ; 174: 31-40, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34044034

RESUMO

Alzheimer's disease is a common cause of dementia, for which no disease-modifying therapy is yet available. Aß3-10-KLH, a vaccine for active immunization, has been shown to prevent pathological changes in young transgenic models of AD, but the effects of treatment with it and its effects on mitochondrial dysfunction remain unclear. We immunized 6-month-old Tg-APPswe/PSEN1dE9 mice with Aß3-10-KLH to analyze whether it is capable of eliminating amyloid-ß after its appearance. The vaccine effectively decreased amyloid-ß deposits, improved cognitive function and ameliorated mitochondrial dysfunction. These results indicate the potential of Aß3-10-KLH as a vaccine to treat AD.

16.
Dent Mater ; 37(8): 1260-1272, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33965251

RESUMO

OBJECTIVE: We aimed to evaluate morphological, mechanical and chemical characteristics at resin-dentin interfaces using multiple combinations of adhesives and resins after a short-term biofilm-induced degradation. METHODS: Cervical cavities were prepared in bovine incisors, treated by Clearfil SE Bond 2 (SE) or FL-Bond II (FL), restored by Clearfil Majesty ES Flow (ES) or Beautifil Flow Plus (BFP) and grouped into SE-ES, SE-BFP, FL-ES and FL-BFP. After biofilm challenge, interfacial gaps and dentin wall lesions were examined by optical coherence tomography (OCT). Gap depth (GD), gap pattern scale (GPS) and dentin wall lesion depth (WLD) were evaluated from confocal laser scanning microscope. Microhardness of dentin lesions was measured with a Vickers microhardness tester. Chemical elements in resins and dentin wall lesions were analyzed by scanning electron microscopy and energy dispersive X-ray spectrometry (SEM/EDS). Morphological structures of interfacial gaps were observed by SEM. RESULTS: OCT could detect adhesive-dentin-bonded and adhesive-dentin-debonded gaps. SE-containing groups showed significantly lower GPS than FL-containing groups. FL-BFP showed significantly lower WLD than FL-ES. Microhardness of dentin wall lesions was higher than that of outer lesions and they showed significant differences in FL-BFP. SE-BFP showed a lower GPS curve and higher intensities of Ca and P in the upper half of dentin wall lesions than other groups. From SEM, microgaps between filler and matrix, break and loss of matrix, separation of adhesive matrix with hybrid layer occurred at interfacial gaps. SIGNIFICANCE: The morphological, mechanical and chemical characteristics of resin-dentin interfacial degradation depend on the component and chemistry of restorative materials.


Assuntos
Colagem Dentária , Dentina , Adesivos , Animais , Biofilmes , Bovinos , Resinas Compostas , Cimentos Dentários , Materiais Dentários , Adesivos Dentinários , Teste de Materiais , Microscopia Eletrônica de Varredura , Cimentos de Resina , Propriedades de Superfície
17.
Analyst ; 146(13): 4154-4160, 2021 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-33977966

RESUMO

Self-assembly performed in ionic liquids (ILs) as a unique solvent promises distinct functions and applications in sensors, therapeutics, and optoelectronic devices due to the rich interactions between nanoparticle building blocks and ILs. However, the general consideration that common nanoparticles are readily destabilized by counterions in an IL has largely prevented researchers from investigating controlled nanoparticle assembly in IL-based systems. This study explores the assembling behaviour of double-stranded (ds) DNA-functionalized gold nanoparticles (dsDNA-AuNPs) in hydrated ionic liquids. The DNA base pair stacking assembly of dsDNA-AuNPs occurs at a low IL concentration (<5%). However, a moderate ionic liquid concentration (5-40%) can de-hybridize dsDNA and leaves single-stranded (ss) DNA stabilizing the AuNPs. In concentrated ionic liquids (>40%), interestingly, the higher ionic strength leads to the assembly of DNA-AuNPs. The triphasic assembly trend is also generally observed regardless of the type of IL. By down-regulation of DNA's melting temperature with the IL, the assembly of DNA-AuNPs affords robust response to a lower temperature range, promising applications in plasmonic devices and range-tunable temperature sensors.


Assuntos
Líquidos Iônicos , Nanopartículas Metálicas , DNA , DNA de Cadeia Simples , Ouro
18.
Biosens Bioelectron ; 189: 113360, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34051383

RESUMO

Test strips represent a class of point-of-care testing (POCT) tools for analysis of a variety of biomarkers towards diagnostics. Conventional test strips offer benefits of simple operation, visualization, and short detection time, along with the drawbacks of relatively low sensitivity and unavailability of quantitative analysis. Recently, the combination of surface-enhanced Raman scattering (SERS) and test strips have evolved to provide a powerful platform capable of ultrasensitive and multiplex detection of extensive analytes of interest. In this review, we focus on the working principles, design strategies and POCT applications of SERS-based test strips. Initially, both lateral and vertical flow test strips are briefly introduced, followed by presentation of various strategies for reforming SERS-based test strips with better detection performance. Applications of SERS-based test strips in diagnosis of disease biomarkers, nucleic acids and toxins are reviewed, with an emphasis on SERS tag design, sensitivity and analytical applicability. Finally, conclusions are made and perspectives on futuristic research directions are given.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Biomarcadores , Testes Imediatos , Análise Espectral Raman
19.
Neuroimage ; 237: 118141, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-33962000

RESUMO

In recent years, there has been significant criticism of functional magnetic resonance imaging (fMRI) studies with small sample sizes. The argument is that such studies have low statistical power, as well as reduced likelihood for statistically significant results to be true effects. The prevalence of these studies has led to a situation where a large number of published results are not replicable and likely false. Despite this growing body of evidence, small sample fMRI studies continue to be regularly performed; likely due to the high cost of scanning. In this report we investigate the use of a moderated t-statistic for performing group-level fMRI analysis to help alleviate problems related to small sample sizes. The proposed approach, implemented in the popular R-package LIMMA (linear models for microarray data), has found wide usage in the genomics literature for dealing with similar issues. Utilizing task-based fMRI data from the Human Connectome Project (HCP), we compare the performance of the moderated t-statistic with the standard t-statistic, as well as the pseudo t-statistic commonly used in non-parametric fMRI analysis. We find that the moderated t-test significantly outperforms both alternative approaches for studies with sample sizes less than 40 subjects. Further, we find that the results were consistent both when using voxel-based and cluster-based thresholding. We also introduce an R-package, LIMMI (linear models for medical images), that provides a quick and convenient way to apply the method to fMRI data.

20.
Artigo em Inglês | MEDLINE | ID: mdl-33818069

RESUMO

Two-dimensional (2D) CrI3 monolayer ferromagnets are key to the development of future miniature spintronic devices and modulating them into a half-metal will greatly expand the application scenarios of CrI3 in nanospintronics. Nevertheless, existing strategies to induce half-metallicity of a CrI3 monolayer remain experimentally challenging and have unstable issues. In this work, the introduction of a 2D electride [Y2C]2+·2e- as an auxiliary layer is shown to be an effective way to achieve the generation of stable half-metallicity in the CrI3 monolayer. When the fully hydrogenated Y2CH2 and ferromagnetic CrI3 monolayer combine to form a heterostructure, surprisingly the appropriate amount of charge injection (0.72 e) turns CrI3 into a half-metal. Hetero-interfacial half-metallicity in CrI3 is an intrinsic one and does not require any chemical functionalization or external physical modification. Therefore, it is advantageous for practical applications of CrI3 in miniature spintronic devices, such as magnetic tunnel junctions, spin valves or spin field-effect transistors. A new strategy of the stable CrI3/Y2CH2 heterostructure was successfully developed to induce the half-metallicity of 2D CrI3 ferromagnets, which is experimentally feasible and half-metallic stable enough. This work paves the way for the application of the CrI3 monolayer in half-metallic-based spintronics.

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