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1.
Cell Rep Med ; : 101510, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38614093

RESUMO

Key gene mutations are essential for colorectal cancer (CRC) development; however, how the mutated tumor cells impact the surrounding normal cells to promote tumor progression has not been well defined. Here, we report that PIK3CA mutant tumor cells transmit oncogenic signals and result in malignant transformation of intestinal epithelial cells (IECs) via paracrine exosomal arachidonic acid (AA)-induced H3K4 trimethylation. Mechanistically, PIK3CA mutations sustain SGK3-FBW7-mediated stability of the cPLA2 protein, leading to the synthetic increase in AA, which is transported through exosome and accumulated in IECs. Transferred AA directly binds Menin and strengthens the interactions of Menin and MLL1/2 methyltransferase. Finally, the combination of VTP50469, an inhibitor of the Menin-MLL interaction, and alpelisib synergistically represses PDX tumors harboring PIK3CA mutations. Together, these findings unveil the metabolic link between PIK3CA mutant tumor cells and the IECs, highlighting AA as the potential target for the treatment of patients with CRC harboring PIK3CA mutations.

2.
Sci Bull (Beijing) ; 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38580551

RESUMO

The rhesus macaque (Macaca mulatta) is a crucial experimental animal that shares many genetic, brain organizational, and behavioral characteristics with humans. A macaque brain atlas is fundamental to biomedical and evolutionary research. However, even though connectivity is vital for understanding brain functions, a connectivity-based whole-brain atlas of the macaque has not previously been made. In this study, we created a new whole-brain map, the Macaque Brainnetome Atlas (MacBNA), based on the anatomical connectivity profiles provided by high angular and spatial resolution ex vivo diffusion MRI data. The new atlas consists of 248 cortical and 56 subcortical regions as well as their structural and functional connections. The parcellation and the diffusion-based tractography were evaluated with invasive neuronal-tracing and Nissl-stained images. As a demonstrative application, the structural connectivity divergence between macaque and human brains was mapped using the Brainnetome atlases of those two species to uncover the genetic underpinnings of the evolutionary changes in brain structure. The resulting resource includes: (1) the thoroughly delineated Macaque Brainnetome Atlas (MacBNA), (2) regional connectivity profiles, (3) the postmortem high-resolution macaque diffusion and T2-weighted MRI dataset (Brainnetome-8), and (4) multi-contrast MRI, neuronal-tracing, and histological images collected from a single macaque. MacBNA can serve as a common reference frame for mapping multifaceted features across modalities and spatial scales and for integrative investigation and characterization of brain organization and function. Therefore, it will enrich the collaborative resource platform for nonhuman primates and facilitate translational and comparative neuroscience research.

3.
Heliyon ; 10(1): e23833, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38261922

RESUMO

Betulinic acid (BA) is a pentacyclic triterpene found in many plant species and has a broad-spectrum anti-tumor effect in various cancers, including colon cancer (CRC). However, its anticancer mechanism in CRC is no clear. RNA sequencing and bioinformatics analysis showed BA up-regulated 378 genes and down-regulated 137 genes in HT29 cells, while 2303 up-regulated and 1041 down-regulated genes were found in SW480 cells. KEGG enrichment analysis showed BA significantly stimulated the expression of metallothionein 1 (MT1) family genes in both HT29 and SW480 cells. Metallothionein 1G (MT1G) was the gene with the highest upregulation of MT1 family genes induced by BA dose-dependently. High MT1G expression enhanced the sensitivity of CRC cells to BA, whereas, MT1G knockdown had the opposite effect in vitro and in vivo. GSEA and GSCA showed genes affected by BA treatment were involved in cell cycle and G2/M checkpoint in CRC. Flow cytometry further exhibited BA reduced the percentage of G0/G1 cells and increased the percentage of G2/M cells in a dose-dependent manner, which could be rescued by MT1G knockdown. Moreover, MT1G also counteracted the BA-induced changes in cell cycle-related proteins (CDK2 and CDK4) and p-Rb. In summary, we have revealed a new anti-tumor mechanism that BA altered the cell cycle progression of CRC cells by upregulating MT1G gene, thereby inhibiting the proliferation of CRC cells.

4.
Front Oncol ; 13: 1162938, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37534250

RESUMO

Regulatory T cells (Tregs) are an important component of the tumor microenvironment; however, the interaction between Tregs and gastric cancer cells is not completely understood. Recent studies have shown that Tregs participate in cancer cell stemness maintenance. In this study, we performed single-cell RNA sequencing of gastric cancer and adjacent tissues and found that Tregs with high TNF expression were recruited to gastric cancer tissues and were significantly correlated with patient survival. TNF+ Tregs significantly contribute to tumor growth and progression. Our studies have further demonstrated that TNF+ Tregs promote the stemness of gastric cancer cells through the IL13/STAT3 pathway. Therefore, blocking the interaction between TNF+ Tregs and gastric cancer cells may be a new approach in the treatment of gastric cancer.

5.
Elife ; 122023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37261976

RESUMO

The available treatments for depression have substantial limitations, including low response rates and substantial lag time before a response is achieved. We applied deep brain stimulation (DBS) to the lateral habenula (LHb) of two rat models of depression (Wistar Kyoto rats and lipopolysaccharide-treated rats) and observed an immediate (within seconds to minutes) alleviation of depressive-like symptoms with a high-response rate. Simultaneous functional MRI (fMRI) conducted on the same sets of depressive rats used in behavioral tests revealed DBS-induced activation of multiple regions in afferent and efferent circuitry of the LHb. The activation levels of brain regions connected to the medial LHb (M-LHb) were correlated with the extent of behavioral improvements. Rats with more medial stimulation sites in the LHb exhibited greater antidepressant effects than those with more lateral stimulation sites. These results indicated that the antidromic activation of the limbic system and orthodromic activation of the monoaminergic systems connected to the M-LHb played a critical role in the rapid antidepressant effects of LHb-DBS. This study indicates that M-LHb-DBS might act as a valuable, rapid-acting antidepressant therapeutic strategy for treatment-resistant depression and demonstrates the potential of using fMRI activation of specific brain regions as biomarkers to predict and evaluate antidepressant efficacy.


Assuntos
Estimulação Encefálica Profunda , Habenula , Ratos , Animais , Estimulação Encefálica Profunda/métodos , Habenula/fisiologia , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Depressão/terapia
6.
Sci Total Environ ; 895: 165005, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37353032

RESUMO

The large-scale utilization of plastic products in agricultural facility production has resulted in considerable accumulation of microplastics in the soil. However, there is a lack of systematic research on the accumulation and distribution of microplastics in facility agriculture. This study examined the presence of microplastics in the 15 representatives of Beijing facility agriculture soil in five districts with different planting years, and assessed the potential pollution risks. The abundance of microplastics in soil layers at a depth of 0-10, 10-20, and 20-30 cm was 896.5 ± 80.0 (range, 160-2120), 630.6 ± 47.0 (180-1340), and 445.3 ± 47.0 (80-1480) items/kg, respectively. Overall, the microplastics were primarily fiber-shaped (72.2 %), white (75.9 %), 1-2 mm in size (37.9 %), and composed of polypropylene and polyethene. The risk assessment indices of the microplastics in the 0-10, 10-20, and 20-30 cm soil layers were 272.1, 289.5, and 291.6, respectively, representing a risk level of 4 in each case. Using the conditional fragmentation model, we found that the microplastics in facility soil featured low stability and small sizes, and their primary sources were organic fertilizer and irrigation water. The number of mulching years, irrigation method, and the amount of organic fertilizer applied, influenced the accumulation of microplastics in the facility soil. This study provides scientific evidence supporting the pollution levels and need for risk control related to microplastics in facility soils.

7.
J Magn Reson ; 351: 107302, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37116433

RESUMO

Ultra-high field (UHF) small animal magnetic resonance imaging (MRI) is a crucial tool permitting investigation of metabolic diseases and identification of imaging biomarkers suitable for clinical diagnosis and translation. Radiofrequency (RF) coils are critical components in enabling acquisition of high-quality rat abdomen MRI data. However, efficient RF coils with high-channel count, capable of sensitive and accelerated rat abdomen imaging at 9.4 T, are not available commercially. The SNR of the commonly-used 9.4 T birdcage coil is relatively weak, particularly in the peripheral area of the subject. In addition, the birdcage is not readily to perform parallel imaging due to unavailability of the required multiple channels. Consequently, the extended scanning duration may cause unnecessary hazards to the rat. In this work, an 8-channel transceiver coil array was designed and constructed to provide good image quality and large coverage for rat abdomen imaging at 9.4 T. The structure and the performance of the developed array was optimized and evaluated by numerical electromagnetic simulations and bench tests, respectively. The MR imaging experiments in phantoms and rat models were also performed on a Bruker 9.4 T preclinical MRI system to validate the feasibility of the proposed design. The coil array supports a one-dimensional acceleration factor up to R = 4, providing good parallel imaging capabilities. These results demonstrated that the proposed 8-channel transceiver coil array for rat imaging has the ability to obtain high spatial resolution of rat abdomen anatomical structure images at 9.4 T.


Assuntos
Imageamento por Ressonância Magnética , Ondas de Rádio , Ratos , Animais , Razão Sinal-Ruído , Imageamento por Ressonância Magnética/métodos , Imagens de Fantasmas , Desenho de Equipamento
8.
Heliyon ; 9(4): e14655, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37025896

RESUMO

It has been proposed that cancer stem cells (CSCs) are responsible for almost all malignant phenotypes of tumors. Long non-coding RNA WT1 antisense RNA (WT1-AS) has been found to be implicated in lung cancer cell stemness. However, the roles and molecular mechanisms of WT1-AS in the development of gastric cancer stem cells (GCSCs) remain unknown. Our present study showed that WT1-AS negatively regulated WT1 expression in GCSCs. WT1-AS knockdown or Wilms' tumor 1 (WT1) overexpression improved GCSC proliferative and migratory capacities, inhibited GCSC apoptosis, potentiated the resistance of GCSCs to 5-FU, promoted GCSC EMT, induced HUVEC angiogenesis, enhanced GCSC stemness, and facilitated in-vitro 3D GCSC aggregate formation. WT1-AS overexpression exerted reverse effects. WT1-AS ameliorated the malignant phenotypes of GCSCs by down-regulating WT1 in vitro. WT1-AS inhibited tumor growth and metastasis, and reduced tumor stemness in GCSCs-derived (s.c., i.p., and i.v.) xenografts in vivo. Moreover, XBP1 was identified as an upstream regulator of WT1-AS in GCSCs. Also, 4 potential WT1-AS downstream targets (i.e. PSPH, GSTO2, FYN, and PHGDH) in GCSCs were identified. Additionally, CACNA2D1 was demonstrated to be a downstream target of the WT1-AS/WT axis. XBP1 or CACNA2D1 knockdown exerted an adverse effect on the maintenance of stem cell-like behaviors and characteristics of GCSCs. In conclusion, WT1-AS weakened the stem cell-like behaviors and characteristics of GCSCs in vitro and in vivo by down-regulating WT1. Investigations into the molecular mechanisms underlying the complex phenotypes of GCSCs might contribute to the better management of gastric cancer.

9.
Cell Discov ; 9(1): 27, 2023 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-36878905

RESUMO

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition that affects social interaction and behavior. Mutations in the gene encoding chromodomain helicase DNA-binding protein 8 (CHD8) lead to autism symptoms and macrocephaly by a haploinsufficiency mechanism. However, studies of small animal models showed inconsistent findings about the mechanisms for CHD8 deficiency-mediated autism symptoms and macrocephaly. Using the nonhuman primate as a model system, we found that CRISPR/Cas9-mediated CHD8 mutations in the embryos of cynomolgus monkeys led to increased gliogenesis to cause macrocephaly in cynomolgus monkeys. Disrupting CHD8 in the fetal monkey brain prior to gliogenesis increased the number of glial cells in newborn monkeys. Moreover, knocking down CHD8 via CRISPR/Cas9 in organotypic monkey brain slices from newborn monkeys also enhanced the proliferation of glial cells. Our findings suggest that gliogenesis is critical for brain size in primates and that abnormal gliogenesis may contribute to ASD.

10.
Int J Surg Case Rep ; 104: 107938, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36827852

RESUMO

INTRODUCTION AND IMPORTANCE: The occurrence of abscesses in the spleen, a substantial abdominal organ with hematopoietic function, is relatively rare in clinical cases and mostly occurs in immunodeficient populations. The early symptoms of splenic abscess are not obvious, and the diagnosis is usually confirmed by a combination of patient symptoms, imaging manifestations and blood culture results. CASE PRESENTATION: A 36-year-old male patient was treated in the emergency room for severe lower abdominal pain and discomfort. An abdominal CT(Computed Tomography) examination initially suggested an acute bowel perforation and an enlarged and abnormally thick spleen. The patient first underwent a repair of the bowel perforation, which was followed by fever and no reduction in abdominal symptoms, while the patient's splenic abscess was then treated with a repeat splenectomy. CLINICAL DISCUSSION: Splenic abscesses mostly occur in immunocompromised patients. The treatment of splenic abscesses includes simple antibacterial medication, percutaneous puncture placement for drainage, and splenectomy for drainage. In our case, the treatment of this patient's splenic abscess was divided into several stages, and we finally used splenectomy for drainage because the patient's symptoms were not significantly better than before and combined with coagulation abnormalities. CONCLUSION: In patients with severe abdominal infection and relevant ancillary tests suggesting abnormal spleen size and density, it is also important to consider whether a splenic abscess has formed and to provide early diagnosis and treatment of splenic abscess while fighting abdominal infection.

11.
Cell Res ; 32(2): 157-175, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34789895

RESUMO

A major obstacle in Alzheimer's disease (AD) research is the lack of predictive and translatable animal models that reflect disease progression and drug efficacy. Transgenic mice overexpressing amyloid precursor protein (App) gene manifest non-physiological and ectopic expression of APP and its fragments in the brain, which is not observed in AD patients. The App knock-in mice circumvented some of these problems, but they do not exhibit tau pathology and neuronal death. We have generated a rat model, with three familiar App mutations and humanized Aß sequence knocked into the rat App gene. Without altering the levels of full-length APP and other APP fragments, this model exhibits pathologies and disease progression resembling those in human patients: deposit of Aß plaques in relevant brain regions, microglia activation and gliosis, progressive synaptic degeneration and AD-relevant cognitive deficits. Interestingly, we have observed tau pathology, neuronal apoptosis and necroptosis and brain atrophy, phenotypes rarely seen in other APP models. This App knock-in rat model may serve as a useful tool for AD research, identifying new drug targets and biomarkers, and testing therapeutics.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/genética , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animais , Disfunção Cognitiva/genética , Modelos Animais de Doenças , Progressão da Doença , Humanos , Camundongos , Camundongos Transgênicos , Ratos
12.
Biochem Biophys Res Commun ; 576: 86-92, 2021 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-34482028

RESUMO

Gastric cancer (GC) is one of the major causes of cancer-related deaths and chemoresistance is a key obstacle to the treatment of GC, particularly in advanced GC. As an active component of saffron stigma, crocetin has important therapeutic effects on various diseases including tumors. However, the therapeutic potential of crocetin targeting GC is still unclear and the underlying mechanisms are remained to be further explored. In this study, crocetin significantly inhibited angiogenesis in GC, including tubes of HUVECs and vasculogenic mimicry (VM) formation of GC cells. Crocetin also suppressed cell proliferation, migration and invasion. To explore which signaling pathway involving in crocetin, HIF-1α, Notch1, Sonic hedgehog (SHH) and VEGF were examined with crocetin treatment and we found that SHH significantly decreased. Crocetin suppressed SHH signaling with SHH, PTCH2, Sufu and Gli1 protein level decreased in western blot assay. In addition, crocetin suppressed SHH secretion in GC and HUVEC cells. The promoted effects on cell migration induced by secreted SHH were also inhibited by crocetin in GC and HUVEC cell co-culture system. Furthermore, recombinant SHH promoted angiogenesis as well as cell migration and proliferation. However, these promoted effects were reversed by crocetin treatment. These results revealed that crocetin suppressed GC angiogenesis and metastasis through SHH signaling pathway, indicating that crocetin may function as an effective therapeutic drug against GC.


Assuntos
Antioxidantes/farmacologia , Carotenoides/farmacologia , Proteínas Hedgehog/antagonistas & inibidores , Neovascularização Patológica/tratamento farmacológico , Neoplasias Gástricas/tratamento farmacológico , Vitamina A/análogos & derivados , Linhagem Celular , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Proteínas Hedgehog/metabolismo , Humanos , Metástase Neoplásica , Neovascularização Patológica/metabolismo , Transdução de Sinais , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Vitamina A/farmacologia
13.
Sci Rep ; 11(1): 10974, 2021 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-34040103

RESUMO

The mid-domain effect (MDE) explains altitudinal patterns of species diversity of mountainous plants at different elevations. However, its application is limited by the species life form and family flora in different layers of plant communities. To verify the MDE hypothesis at the plant community level, we chose a mountain with representative characteristics of the study area in the east of the Loess Plateau, China, such as obvious elevation (from 1324 to 2745 m) and latitude (from 36° 23' to 39° 03') gradients and considerable vegetation types (mainly coniferous and broad-leaved forests). We measured the life forms, families, and species diversity indices of tree, shrub, and herb communities along different elevations. We determined that the family numbers of the herb and shrub communities presented unimodal patterns across an altitudinal gradient, and the highest values occurred at intermediate elevations. The importance values of dominant families in the shrub and tree communities presented unimodal patterns, but the lowest values occurred at intermediate elevations. The species diversity indices of the herb, shrub, and tree communities conformed to unimodal change patterns following an altitudinal gradient, but the greatest diversity occurred at high, low, and intermediate elevations, respectively. At higher elevations, forbs and grasses grew well, whereas sedges grew well at lower elevations. Responses of different tree life forms to the altitudinal gradient were greater for evergreen coniferous tree species than for deciduous coniferous and deciduous broad-leaved tree species. We concluded that the MDE hypothesis of species diversity for mountainous plants is influenced greatly by the community life form and family at the plant community level in a temperate semi-arid region of the Loess Plateau, China. This conclusion tested and modified the MDE hypothesis and may be valuable for fueling prediction of biodiversity models and for the comparison with similar studies in arid and semi-arid mountainous regions.


Assuntos
Biodiversidade , Florestas , Árvores , Altitude , China
14.
Oncogene ; 40(12): 2200-2216, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33649532

RESUMO

Cancer stem cells (CSCs) are characterized by robust self-renewal and tumorigenesis and are responsible for metastasis, drug resistance, and angiogenesis. However, the molecular mechanisms for the regulation of CSC homeostasis are incompletely understood. This study demonstrated that the interleukin-17 (IL-17)B/IL-17RB signaling cascade promotes the self-renewal and tumorigenesis of CSCs by inducing Beclin-1 ubiquitination. We found that IL-17RB expression was significantly upregulated in spheroid cells and Lgr5-positive cells from the same tumor tissues of patients with gastric cancer (GC), which was closely correlated with the degree of cancer cell differentiation. Recombinant IL-17B (rIL-17B) promoted the sphere-formation ability of CSCs in vitro and enhanced tumor growth and metastasis in vivo. Interestingly, IL-17B induced autophagosome formation and cleavage-mediated transformation of LC3 in CSCs and 293T cells. Furthermore, inhibition of autophagy activation by ATG7 knockdown reversed rIL-17B-induced self-renewal of GC cells. In addition, we showed that IL-17B also promoted K63-mediated ubiquitination of Beclin-1 by mediating the binding of tumor necrosis factor receptor-associated factor 6 to Beclin-1. Silencing IL-17RB expression abrogated the effects of IL-17B on Beclin-1 ubiquitination and autophagy activation in GC cells. Finally, we showed that IL-17B level in the serum of GC patients was positively correlated with IL-17RB expression in GC tissues, and IL-17B could induce IL-17RB expression in GC cells. Overall, the results elucidate the novel functions of IL-17B for CSCs and suggest that the intervention of the IL-17B/IL-17RB signaling pathway may provide new therapeutic targets for the treatment of cancer.


Assuntos
Proteína Beclina-1/genética , Carcinogênese/genética , Interleucina-17/genética , Morfogênese/genética , Receptores de Interleucina-17/genética , Autofagia/genética , Diferenciação Celular/genética , Autorrenovação Celular/genética , Resistencia a Medicamentos Antineoplásicos/genética , Homeostase , Humanos , Metástase Neoplásica , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Neovascularização Patológica/genética , Neovascularização Patológica/patologia , Transdução de Sinais/genética , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Ubiquitinação/genética
15.
Food Chem Toxicol ; 150: 112069, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33607219

RESUMO

Lately, long non-coding RNA (lncRNA) is recognized as a key regulator of gastric cancer (GC) which has aroused great interest in the fields of medicine, toxicology, and functional food. Studies related to LncRNA expression microarray data indicate that BX357664 is down-regulated in GC specimens. However, the expression pattern and molecular mechanism of BX357664 in GC have not been studied so far. The purpose of this study was to investigate the expression of lncRNA BX357664 in GC and its function in GC cell lines. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect the level of BX357664 in 50 pairs of cancer tissues and adjacent non-cancer tissues collected from GC patients. It was found that BX357664 level was lowered in cancer specimens than adjacent non-cancer tissues and correlated with tumor size and TNM stage. Also, we used cell counting kit 8 (CCK8), cell clone formation assay and transwell assay, which affirmed that up-regulation of BX357664 inhibited the proliferation, migration, and invasion of GC cells, but promoted apoptosis. In the dual-luciferase report analysis, BX357664 acted as a miR-183-3p ceRNA to target and regulate the expression of PTEN and affect the PI3K/AKT pathway. These results indicate that BX357664 can inhibit the proliferation and metastasis of GC through the miR-183-3p/PTEN/PI3K/AKT pathway, which may serve as potential targets for the treatment of GC in the future.


Assuntos
Proteínas de Membrana/metabolismo , MicroRNAs/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Linhagem Celular Tumoral , Regulação para Baixo , Células Epiteliais , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Nus , MicroRNAs/genética , Pessoa de Meia-Idade , Neoplasias Experimentais , PTEN Fosfo-Hidrolase/genética , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , RNA Longo não Codificante , Neoplasias Gástricas
16.
Front Neurosci ; 15: 771980, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35002602

RESUMO

Implantable brain electrophysiology electrodes are valuable tools in both fundamental and applied neuroscience due to their ability to record neural activity with high spatiotemporal resolution from shallow and deep brain regions. Their use has been hindered, however, by the challenges in achieving chronically stable operations. Furthermore, implantable depth neural electrodes can only carry out limited data sampling within predefined anatomical regions, making it challenging to perform large-area brain mapping. Minimizing inflammatory responses and associated gliosis formation, and improving the durability and stability of the electrode insulation layers are critical to achieve long-term stable neural recording and stimulation. Combining electrophysiological measurements with simultaneous whole-brain imaging techniques, such as magnetic resonance imaging (MRI), provides a useful solution to alleviate the challenge in scalability of implantable depth electrodes. In recent years, various carbon-based materials have been used to fabricate flexible neural depth electrodes with reduced inflammatory responses and MRI-compatible electrodes, which allows structural and functional MRI mapping of the whole brain without obstructing any brain regions around the electrodes. Here, we conducted a systematic comparative evaluation on the electrochemical properties, mechanical properties, and MRI compatibility of different kinds of carbon-based fiber materials, including carbon nanotube fibers, graphene fibers, and carbon fibers. We also developed a strategy to improve the stability of the electrode insulation without sacrificing the flexibility of the implantable depth electrodes by sandwiching an inorganic barrier layer inside the polymer insulation film. These studies provide us with important insights into choosing the most suitable materials for next-generation implantable depth electrodes with unique capabilities for applications in both fundamental and translational neuroscience research.

17.
J Air Waste Manag Assoc ; : 1-7, 2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-33006923

RESUMO

Separating cathode material and Al foil from spent lithium-ion batteries (LIBs) is a critical step for LIBs recycling. As compared to chemical dissolving and decomposition, the pyrolysis pretreatment is an alternative and simple method. In this work, the pyrolysis kinetics of cathode material were comparatively studied using various isoconversional methods, including Flynn-Wall-Ozawa (FWO), Friedman, Kissinger-Akahira-Sunose, Starink, Tang, and Boswell. The thermal degradation mechanism was investigated by the Coats-Redfern (CR) and master-plot methods as well. The thermogravimetric analysis revealed that cathode material decomposition could be divided into three stages with mass losses of 1.51%, 0.787%, and 0.449%, respectively. Activation energy (Eα) calculated using the six model-free methods showed a similar trend, gradually increasing as the degree of conversion (α) increased from 0.001 to 0.009, and then significantly elevating. The FWO method gave the best fitting and Eα values first increased from 12.032 to 24.433 kJ·mol-1 with α elevating from 0.001 to 0.009, then increased further to 43.187 kJ·mol-1. Both CR and Criado methods indicated that the degradation of cathode material can be explained by the diffusion models.Implications: The rapid growth in the production and consumption of lithium-ion batteries (LIBs) for portable electronic devices and electric vehicles has resulted in an increasing number of spent LIBs. Thermal treatment offers advantages of high-efficiency and simple operation. Understanding the thermal process of spent LIBs and probing its kinetic are significant for the large-scale treatment. Through this study, it will be significant for the reactor designing and optimizing in practice.

18.
Neurosci Bull ; 36(12): 1454-1473, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33108588

RESUMO

The frontal pole cortex (FPC) plays key roles in various higher-order functions and is highly developed in non-human primates. An essential missing piece of information is the detailed anatomical connections for finer parcellation of the macaque FPC than provided by the previous tracer results. This is important for understanding the functional architecture of the cerebral cortex. Here, combining cross-validation and principal component analysis, we formed a tractography-based parcellation scheme that applied a machine learning algorithm to divide the macaque FPC (2 males and 6 females) into eight subareas using high-resolution diffusion magnetic resonance imaging with the 9.4T Bruker system, and then revealed their subregional connections. Furthermore, we applied improved hierarchical clustering to the obtained parcels to probe the modular structure of the subregions, and found that the dorsolateral FPC, which contains an extension to the medial FPC, was mainly connected to regions of the default-mode network. The ventral FPC was mainly involved in the social-interaction network and the dorsal FPC in the metacognitive network. These results enhance our understanding of the anatomy and circuitry of the macaque brain, and contribute to FPC-related clinical research.


Assuntos
Mapeamento Encefálico , Córtex Cerebral/anatomia & histologia , Macaca , Algoritmos , Animais , Córtex Cerebral/diagnóstico por imagem , Feminino , Aprendizado de Máquina , Imageamento por Ressonância Magnética , Masculino , Vias Neurais
19.
ACS Omega ; 5(29): 17850-17856, 2020 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-32743155

RESUMO

The waste from end-of-life electrical and electronic equipment has become the fastest growing waste problem in the world. The difficult-to-treat waste-printed circuit boards (WPCBs), which are nearly 3-6 wt % of the total electronic waste, generate great environmental concern nowadays. For WPCB treatment and recycling, the mechanical-physical method has turned out to be more technologically and economically feasible. In this work, the mechanical-physical treatment and recycling technologies for WPCBs were investigated, and future research was directed as well. Removing electric and electronic components (EECs) from WPCBs is critical for their crushing and metal recovery; however, environmentally friendly and high-efficiency removal techniques need be developed. Concentrated metals rich in Cu, Al, Au, Pb, and Sn recovered from WPCBs need be further refined to add to their economic values. The low value-added nonmetallic fraction of waste-printed circuit boards (NMF-WPCBs) accounts for approximately 60 wt % of the WPCBs. From the perspective of environmental management, a zero-waste approach to recycling them should be developed to gain values. Preparing polymer composites and geopolymers offers many advantages and has potential applications in various fields, especially as construction and building materials. However, the mechanical and thermal properties of NMF-WPCBs composites should be further improved for preparing polymer composites. Surface modification or filler blending could be applied to improve the interfacial comparability between NMF-WPCBs and the polymer matrix. The NMF-WPCBs shows potential in preparing cement mortar and geological polymers, but the environmental safety resulting from metals needs to be taken into account. This study will provide a significant reference for the industrial recycling of NMF-WPCBs.

20.
NMR Biomed ; 33(10): e4369, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32729642

RESUMO

The neuroimaging of nonhuman primates (NHPs) realised with magnetic resonance imaging (MRI) plays an important role in understanding brain structures and functions, as well as neurodegenerative diseases and pathological disorders. Theoretically, an ultrahigh field MRI (≥7 T) is capable of providing a higher signal-to-noise ratio (SNR) for better resolution; however, the lack of appropriate radiofrequency (RF) coils for 9.4 T monkey MRI undermines the benefits provided by a higher field strength. In particular, the standard volume birdcage coil at 9.4 T generates typical destructive interferences in the periphery of the brain, which reduces the SNR in the neuroscience-focused cortex region. Also, the standard birdcage coil is not capable of performing parallel imaging. Consequently, extended scan durations may cause unnecessary damage due to overlong anaesthesia. In this work, assisted by numerical simulations, an eight-channel receive RF coil array was specially designed and manufactured for imaging NHPs at 9.4 T. The structure and geometry of the proposed receive array was optimised with numerical simulations, so that the SNR enhancement region was particularly focused on monkey brain. Validated with rhesus monkey and cynomolgus monkey brain images acquired from a 9.4 T MRI scanner, the proposed receive array outperformed standard birdcage coil with higher SNR, mean diffusivity and fractional anisotropy values, as well as providing better capability for parallel imaging.


Assuntos
Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética/instrumentação , Ondas de Rádio , Animais , Simulação por Computador , Imagem de Difusão por Ressonância Magnética , Macaca fascicularis , Macaca mulatta , Camundongos , Imagens de Fantasmas , Razão Sinal-Ruído
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