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1.
Nature ; 613(7944): 485-489, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36653565

RESUMO

Antiferromagnetic spintronics1-16 is a rapidly growing field in condensed-matter physics and information technology with potential applications for high-density and ultrafast information devices. However, the practical application of these devices has been largely limited by small electrical outputs at room temperature. Here we describe a room-temperature exchange-bias effect between a collinear antiferromagnet, MnPt, and a non-collinear antiferromagnet, Mn3Pt, which together are similar to a ferromagnet-antiferromagnet exchange-bias system. We use this exotic effect to build all-antiferromagnetic tunnel junctions with large nonvolatile room-temperature magnetoresistance values that reach a maximum of about 100%. Atomistic spin dynamics simulations reveal that uncompensated localized spins at the interface of MnPt produce the exchange bias. First-principles calculations indicate that the remarkable tunnelling magnetoresistance originates from the spin polarization of Mn3Pt in the momentum space. All-antiferromagnetic tunnel junction devices, with nearly vanishing stray fields and strongly enhanced spin dynamics up to the terahertz level, could be important for next-generation highly integrated and ultrafast memory devices7,9,16.

2.
Nano Lett ; 24(2): 584-591, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38165127

RESUMO

Cu2S likely plays an important role in the sharp resistivity transition of LK-99. Nevertheless, this immediately arouses an intriguing question of whether the extraordinary room-temperature colossal magnetoresistance in the initial reports, which has been less focused, originates from Cu2S as well. To resolve this issue, we have systematically investigated the electrical transport and magnetotransport properties of near-stoichiometric Cu2S pellets and thin films. Neither Cu2S nor LK-99 containing Cu2S in this study was found to exhibit the remarkable magnetoresistance effect implied by Lee et al. This implies that Cu2S could not account for all of the intriguing transport properties of the initially reported LK-99, and the initially reported LK-99 samples might contain magnetic impurities. Moreover, based on the crystal-structure-sensitive electrical properties of Cu2S, we have constructed a piezoelectric-strain-controlled device and obtained a giant and reversible resistance modulation of 2 orders of magnitude at room temperature, yielding a huge gauge factor of 160,000.

3.
J Environ Manage ; 360: 121129, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38749128

RESUMO

Aboveground vegetation restoration shapes the soil microbial community structure and affects microbial resource acquisition. However, the changes in soil microbial resource limitation in subsoil during vegetation restoration are still unclear. In this study, the microbial community structure and resource limitation in an alpine meadow soil profile that had undergone natural restoration for short-term (4-year) and long-term (10-year) restoration in response to vegetation restoration were explored through high-throughput sequencing analysis and extracellular enzyme stoichiometry (EES). There was no significant difference in microbial composition and α diversity between short- and long-term restoration soils. Soil microorganisms in this alpine meadow were mainly limited by phosphorus. Carbon limitation of soil microorganisms was significantly decreased in each layer (0-15, 15-30, 30-45, 45-60, and 60-80 cm corresponding to L1, L2, L3, L4, and L5, respectively) of long-term restoration soils when compared to that of the short-term restoration soil layers, while phosphorus limitation of microorganisms in subsoil (60-80 cm) was significantly increased by 17.38%. Soil nutrients, pH, moisture content, and microbial composition are the main drivers of microbial resource limitation in restoration, and their effects on microbial resource limitation were different in short- and long-term restoration. Meanwhile, key microbial taxa have a significant impact on microbial resource limitation, especially in short-term restoration soils. This study suggested that vegetation restoration significantly affected soil microbial resource limitation, and could alleviate microbial resource limitations by adding nutrients, thus accelerating the process of vegetation restoration in alpine ecosystems.


Assuntos
Pradaria , Microbiologia do Solo , Solo , Solo/química , Fósforo/análise , Microbiota , Carbono/metabolismo
4.
Hum Mol Genet ; 31(2): 300-308, 2021 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-34409462

RESUMO

Although >80 psoriasis genetic risk loci have been reported through genome-wide association studies (GWASs), the genetic mechanism of psoriasis remains unclear. To identify novel candidate genes associated with psoriasis and reveal the potential effects of genetic factors in the development of psoriasis, we conducted a transcriptome-wide association study (TWAS) based on summary statistics from GWAS of psoriasis (5175 cases and 447 089 controls) and gene expression levels from six tissues datasets (blood and skin). We identified 11 conditionally independent genes for psoriasis after Bonferroni corrections, such as the most significant genes UBLCP1 (PYFS = 2.98 × 10-16) and LCE3C (PSNSE = 9.72 × 10-12, PSSE = 6.24 × 10-12). The omnibus test identified additional five genes associated with psoriasis via the joint association model from multiple reference tissues. Among the 16 identified genes, 5 genes (CTSW, E1F1AD, KLRC3, FIBP and EFEMP2) were regarded as novel genes for psoriasis. We evaluated the 16 candidate genes by querying public databases and identified 11 differentially expressed genes and 8 genes proved by the knockout mice models. Through GO enrichment analyses, we found that TWAS genes were enriched in the known GO terms associated with skin development, such as cornified envelope (P = 4.80 × 10-8) and peptide cross-linking (P = 1.50 × 10-7). Taken together, our results detected multiple novel candidate genes for psoriasis, providing clues for understanding the genetic mechanism of psoriasis.


Assuntos
Psoríase , Transcriptoma , Animais , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla/métodos , Camundongos , Polimorfismo de Nucleotídeo Único/genética , Psoríase/genética , Transcriptoma/genética
5.
Environ Sci Technol ; 57(44): 16884-16894, 2023 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-37857299

RESUMO

Dissolved organic matter (DOM) is critical for soil carbon sequestration in terrestrial ecosystems. DOM molecular composition varies with soil depth. However, the spatial heterogeneity of depth-dependent DOM in response to climate warming remains unclear, especially in alpine ecosystems. In this study, the DOM of alpine meadow soil samples was characterized comprehensively by using spectroscopy and mass spectrometry, and open-top chambers (OTCs) were employed to simulate warming. It was found that climate warming had the greatest impact on the upper layer (0-30 cm), followed by the lower layer (60-80 cm), while the middle layer (30-60 cm) was the most stable among the three soil layers. The reasons for the obvious changes in DOM in the upper and lower layers of soil were further explained based on biotic and abiotic factors. Specifically, soil nutrients (NH4+-N, NO3--N, TC, and TP) affected the molecular composition of DOM in layer L1 (0-15 cm), while pH affected layer L5 (60-80 cm). Gemmatimonadetes, Proteobacteria, and Actinobacteria played important roles in the composition of DOM in the L5 layer (60-80 cm), while the dominant fungal groups affecting the DOM composition increased in the L1 layer (0-15 cm) under warming. In summary, this research has contributed to a deeper understanding of depth-dependent changes in DOM molecular composition in alpine ecosystems.


Assuntos
Ecossistema , Solo , Solo/química , Tibet , Matéria Orgânica Dissolvida , Clima , Bactérias , Carbono
6.
Int J Mol Sci ; 24(24)2023 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-38139398

RESUMO

This study reports the whole-genome sequence of Lactiplantibacillus plantarum cqf-43 isolated from healthy sow feces. Based on genomic analysis, we performed a comprehensive safety assessment of strain cqf-43, using both in vitro and in vivo experiments, and explored its probiotic potential. The total genome length measures 3,169,201 bp, boasting a GC content of 44.59%. Through phylogenetic analyses, leveraging both 16S rRNA gene and whole-genome sequences, we confidently categorize strain cqf-43 as a member of Lactiplantibacillus. Genome annotation using Prokka unveiled a total of 3141 genes, encompassing 2990 protein-coding sequences, 71 tRNAs, 16 rRNAs, and 1 tmRNA. Functional annotations derived from COG and KEGG databases highlighted a significant abundance of genes related to metabolism, with a notable emphasis on carbohydrate utilization. The genome also revealed the presence of prophage regions and CRISPR-Cas regions while lacking virulence and toxin genes. Screening for antibiotic resistance genes via the CARD database yielded no detectable transferable resistance genes, effectively eliminating the potential for harmful gene transfer. It is worth highlighting that the virulence factors identified via the VFDB database primarily contribute to bolstering pathogen resilience in hostile environments. This characteristic is particularly advantageous for probiotics. Furthermore, the genome is devoid of menacing genes such as hemolysin, gelatinase, and biogenic amine-producing genes. Our investigation also unveiled the presence of three unannotated secondary metabolite biosynthetic gene clusters, as detected by the online tool antiSMASH, suggesting a great deal of unknown potential for this strain. Rigorous in vitro experiments confirmed tolerance of strain cqf-43 in the intestinal environment, its antimicrobial efficacy, sensitivity to antibiotics, absence of hemolysis and gelatinase activity, and its inability to produce biogenic amines. In addition, a 28-day oral toxicity test showed that the strain cqf-43 did not pose a health hazard in mice, further establishing it as a safe strain.


Assuntos
Genoma Bacteriano , Probióticos , Animais , Feminino , Suínos , Camundongos , RNA Ribossômico 16S , Filogenia , Antibacterianos , Gelatinases/genética , Análise de Sequência
7.
Molecules ; 28(8)2023 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-37110614

RESUMO

Chronic inflammatory disease (CID) is a category of medical conditions that causes recurrent inflammatory attacks in multiple tissues. The occurrence of CID is related to inappropriate immune responses to normal tissue substances and invading microbes due to many factors, such as defects in the immune system and imbalanced regulation of commensal microbes. Thus, effectively keeping the immune-associated cells and their products in check and inhibiting aberrant activation of the immune system is a key strategy for the management of CID. Canthin-6-ones are a subclass of ß-carboline alkaloids isolated from a wide range of species. Several emerging studies based on in vitro and in vivo experiments reveal that canthin-6-ones may have potential therapeutic effects on many inflammatory diseases. However, no study has yet summarized the anti-inflammatory functions and the underlying mechanisms of this class of compounds. This review provides an overview of these studies, focusing on the disease entities and the inflammatory mediators that have been shown to be affected by canthin-6-ones. In particular, the major signaling pathways affected by canthin-6-ones, such as the NLR family pyrin domain containing 3 (NLRP3) inflammasome and the NF-κB signaling pathway, and their roles in several CIDs are discussed. Moreover, we discuss the limitations in studies of canthin-6-ones and provide possible solutions. In addition, a perspective that may suggest possible future research directions is provided. This work may be helpful for further mechanistic studies and possible therapeutic applications of canthin-6-ones in the treatment of CID.


Assuntos
Inflamassomos , Mediadores da Inflamação , Mediadores da Inflamação/metabolismo , Inflamassomos/metabolismo , Carbolinas/farmacologia , Carbolinas/uso terapêutico , NF-kappa B/metabolismo , Transdução de Sinais , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo
8.
J Anim Physiol Anim Nutr (Berl) ; 107(3): 867-877, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36541276

RESUMO

The present study investigated the effects of supplementing bioactive peptides derived from rapeseed protein (rapeseed peptide, Rsp) on the growth performance, serum biochemistry and faecal micro-organism composition of weaned piglets. Sixty Duroc × Landrace × Yorkshire weaned piglets of similar weights were randomly divided into three groups. The control group (NC) was fed a basal diet, and the two treatment groups, Rsp-1 and Rsp-2, were fed a basal diet supplemented with 1% or 2% Rsp, respectively, for 28 days. Each treatment consisted of five replicates with four piglets per replicate. The results showed that Rsp treatment significantly improved the average daily gain and had a better feed-to-gain ratio (p < 0.05). The diarrhoea incidence and indices of Rsp-1 and Rsp-2 groups were significantly lower than the NC group (p < 0.05), and the effect of Rsp-2 on reducing the incidence of diarrhoea was significantly higher than that of Rsp-1 (p < 0.05). The serum albumin, serum immunoglobulin A and catalase levels of the Rsp-1 and Rsp-2 groups were significantly better than the NC group (p < 0.05). Additionally, Rsp treatment significantly gained the relative abundance of faecal Lactobacillaceae and decreased the relative abundance of faecal Eubacterium_coprostanoligenes_group, Treponema and Coprococcus (p < 0.05). In summary, Rsp supplementation improved the growth performance, ameliorated the diarrhoea, enhanced the immune and antioxidant functions and changed the composition of faecal micro-organisms in piglets. These findings indicate that Rsp positively affected the health of weaned piglets.


Assuntos
Brassica napus , Animais , Suínos , Suplementos Nutricionais , Dieta/veterinária , Peptídeos , Diarreia/prevenção & controle , Diarreia/veterinária
9.
Curr Issues Mol Biol ; 44(5): 2038-2053, 2022 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-35678667

RESUMO

Skeletal muscle satellite cells (SMSCs), which are multifunctional muscle-derived stem cells, can differentiate into adipocytes. Long-chain non-coding RNA (lncRNA) has diverse biological functions, including the regulation of gene expression, chromosome silencing, and nuclear transport. However, the regulatory roles and mechanism of lncRNA during adipogenic transdifferentiation in muscle cells have not been thoroughly investigated. Here, porcine SMSCs were isolated, cultured, and induced for adipogenic differentiation. The expressions of lncRNA and mRNA at different time points during transdifferentiation were analysed using RNA-seq analysis. In total, 1005 lncRNAs and 7671 mRNAs showed significant changes in expression at differential differentiation stages. Time-series expression analysis showed that the differentially expressed (DE) lncRNAs and mRNAs were clustered into 5 and 11 different profiles with different changes, respectively. GO, KEGG, and REACTOME enrichment analyses revealed that DE mRNAs with increased expressions during the trans-differentiation were mainly enriched in the pathways for lipid metabolism and fat cell differentiation. The genes with decreased expressions were mainly enriched in the regulation of cell cycle and genetic information processing. In addition, 1883 DE mRNAs were regulated by 193 DE lncRNAs, and these genes were related to the controlling in cell cycle mainly. Notably, three genes in the fatty acid binding protein (FABP) family significantly and continuously increased during trans-differentiation, and 15, 13, and 11 lncRNAs may target FABP3, FABP4, and FABP5 genes by cis- or trans-regulation, respectively. In conclusion, these studies identify a set of new potential regulator for adipogenesis and cell fate and help us in better understanding the molecular mechanisms of trans-differentiation.

10.
J Microsc ; 288(1): 10-15, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35916115

RESUMO

Convergent beam electron diffraction (CBED) was used to profile the thickness of aluminium alloys foils prepared by using the twinjet electropolishing method. The two-beam CBED condition was obtained by exciting the { 200 } $\{ {200} \}$ and { 111 } $\{ {111} \}$ aluminium diffracted g-vector. The aluminium alloy foil thicknesses were calculated at different distances from the sample hole edge. In areas where only one Kossel-Möllenstedt (K-M) minima fringe was obtained, the thickness was determined by matching the experimental with simulated convergent beam diffraction patterns. In areas far away from the sample edge, the thickness of foils was high enough to generate at least two (K-M) minima fringes, required for linear regression fitting.

11.
Clin Lab ; 68(6)2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35704726

RESUMO

BACKGROUND: The outbreak of SARS-CoV-2 lead to a worldwide pandemic which poses substantial challenges to public health. METHODS: We enrolled 102 consecutive recovered patients with laboratory-confirmed SARS-CoV-2 infection. Epidemiological and demographic characteristics, temporal dynamic profiles of laboratory tests and findings on chest CT radiography, and clinical outcomes were collected and analyzed. RESULTS: Independent risk factors for prolonged fever, viral RNA shedding or radiologic recovery included age of more than 44 years, female gender, having symptoms of cough and fever, a delay from the symptom onset to hospitalization of more than 3 days, a lower CD4 count of less than 500/µL on admission, and severe or critical illness in hospitalization. The estimated median time from symptom onset was 6.4 (5.5 - 7.4) days to peak viral load, 9.1 (7.9 - 10.4) days to afebrile, 8 (6.7 - 9.4) days to worst radiologic finding, 12.7 (11.2 - 14.3) days to viral RNA negativity, and 26.7 (23.8 - 29.9) days to radiologic resolution. This study included the entire cross-section of patients seen in our clinical practice and reflected the real-world situation. CONCLUSIONS: These findings provide the rationale for strategies of active symptom monitoring, timing of quarantine and antiviral interventions, and duration of radiologic follow-up in patients with COVID-19.


Assuntos
COVID-19 , Adulto , Feminino , Febre , Humanos , RNA Viral/genética , Estudos Retrospectivos , SARS-CoV-2 , Eliminação de Partículas Virais
12.
Parasitol Res ; 121(8): 2457-2460, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35767047

RESUMO

Predictive models for prognosis of small sample advanced schistosomiasis patients have not been well studied. We aimed to construct prognostic predictive models of small sample advanced schistosomiasis patients using two machine learning algorithms, k nearest neighbour (kNN) and support vector machine (SVM) utilising routinely available data under the government medical assistance programme. The predictive models were derived from 229 patients from Xiantao and externally validated by 77 patients of Jiayu, two county-level cities in Hubei province, China. Candidate predictors were selected according to expert opinions and literature reports, including clinical features, sociodemographic characteristics, and medical examinations results. An area under the receiver operating characteristic curve (AUC), sensitivity, and specificity were used to evaluate the models' predictive performances. The AUC values were 0.879 for the kNN model and 0.890 for the SVM model in the training set, 0.852 for the kNN model, and 0.785 for the SVM model in the external validation set. The kNN and SVM models can be used to improve the health services provided by healthcare planners, clinicians, and policymakers.


Assuntos
Esquistossomose , Máquina de Vetores de Suporte , Humanos , Aprendizado de Máquina , Prognóstico , Curva ROC , Esquistossomose/diagnóstico
13.
Ecotoxicol Environ Saf ; 237: 113511, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35489137

RESUMO

Sphingosine kinase 1 (SphK1) is an important signaling molecule for cell proliferation and survival. However, the role of SphK1 in acrylamide (ACR)-induced nerve injury remains unclear. The purpose of this study was to investigate the role and potential mechanism of SphK1 in ACR-induced nerve injury. Liquid chromatography triple quadrupole tandem mass spectrometry (LC-MS/MS) and reverse transcription-quantitative PCR (RT-qPCR) were used to detect sphingosine 1-phosphate (S1P) content in serum and SphK1 content in whole blood from an occupational work group exposed to ACR compared to a non-exposed group. For in vitro experiments, SphK1 in human SH-SY5Y neuroblastoma cells was activated using SphK1-specific activator phorbol 12-myristate 13-acetate (PMA). Our research also utilized cell viability assays, flow cytometry, western blots, RT-qPCR and related protein detection to assess activity of the mitogen activated protein kinase (MAPK) signaling pathway. The results of the population study showed that the contents of SphK1 and S1P in the ACR-exposed occupational contact group were lower than in the non-exposed group. The results of in vitro experiments showed that expression of SphK1 decreased with the increase in ACR concentration. Activating SphK1 improved the survival rate of SH-SY5Y cells and decreased the apoptosis rate. Activating SphK1 in SH-SY5Y cells also regulated MAPK signaling, including enhancing the phosphorylation of extracellular signal-regulated protein kinases (ERK) and inhibiting the phosphorylation of c-Jun N-terminal kinase (JNK) and p38. These results suggest that activating SphK1 can protect against nerve cell damage caused by ACR.


Assuntos
Acrilamida , Espectrometria de Massas em Tandem , Acrilamida/toxicidade , Cromatografia Líquida , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Neurônios/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)
14.
Immunology ; 164(3): 507-523, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34115389

RESUMO

Loss of the B2M gene is associated with tumour immune escape and resistance to immunotherapy. However, genetic alterations of the B2M gene are rare. We performed an integrative analysis of the mutational and transcriptional profiles of large cohorts of non-small-cell lung cancer (NSCLC) patients and found that epigenetic downregulation of B2M is common. B2M-low tumours exhibit a suppressive immune microenvironment characterized by reduced infiltration of immune cells of various lineages; in B2M-high tumours, more T and natural killer cells are present, but their activities are constrained by immune checkpoint molecules, indicating the diverse mechanisms of immune evasion. High levels of B2M mRNA, but not PD-L1, are correlated with an enhanced response to PD-1-based immunotherapy, suggesting its value for immunotherapy response prediction in solid tumours. Notably, a high tumour mutation burden (TMB) is associated with low B2M expression, which may explain the poor predictive value of the TMB in some situations. In syngeneic mouse models, genetic ablation of B2M in tumour cells causes resistance to PD-1-based immunotherapy, and B2M knockdown also diminishes the therapeutic efficacy. Moreover, forced expression of B2M in tumour models improves the response to immunotherapy, suggesting that B2M levels have significant impacts on treatment outcomes. Finally, we provide insight into the roles of transcription factors and KRAS mutations in B2M expression and the anticancer immune response. In conclusion, genetic and epigenetic regulation of B2M fundamentally shapes the NSCLC immune microenvironment and may determine the response to checkpoint blockade-based immunotherapy.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/imunologia , Neoplasias Pulmonares/imunologia , Microglobulina beta-2/genética , Animais , Antígeno B7-H1/genética , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Conjuntos de Dados como Assunto , Modelos Animais de Doenças , Regulação para Baixo/imunologia , Resistencia a Medicamentos Antineoplásicos/genética , Epigênese Genética/imunologia , Regulação Neoplásica da Expressão Gênica/imunologia , Técnicas de Silenciamento de Genes , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos , Mutação , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Proteínas Proto-Oncogênicas p21(ras)/genética , Evasão Tumoral/genética , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia
15.
Exp Eye Res ; 208: 108618, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33989670

RESUMO

Uveitis is a diverse group of sight-threatening intraocular inflammatory diseases usually causing eye redness, pain, blurred vision, and sometimes blindness. Although the exact pathogenesis of uveitis is not yet clear, accumulating evidences have shown that an imbalanced regulation of immune responses caused by a combination of genetic and environmental factors are implicated in the pathogenesis of this disease. As critical regulators of inflammation, inflammasomes have been assumed to play a role in the pathogenesis of uveitis. Recent studies have reported the association between a number of genetic variants in inflammasome related genes (such as NLRP3, NLRP1, NLRC4 and AIM2) with increased risk to uveitis. Mounting evidence have shown an aberrant activation of the NLRP3 inflammasome in both uveitis patients and murine models of uveitis. Some studies explored the intervention of uveitis via modulating inflammasome activity in the eye. This review aims at summarizing the main findings of these studies, proposing the possible mechanism whereby inflammasomes affect the susceptibility to develop uveitis, and giving a perspective for future studies, which may further improve our understanding about the role of inflammasomes and related cytokines in the pathogenesis of uveitis, and may hopefully lead to new therapeutics by targeting inflammasomes.


Assuntos
Citocinas/metabolismo , Inflamassomos/metabolismo , Uveíte/metabolismo , Animais , Humanos
16.
J Microsc ; 282(2): 101-112, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33210738

RESUMO

Recently, the dual beam Xe+ plasma focused ion beam (Xe+ pFIB) instrument has attracted increasing interest for site-specific transmission electron microscopy (TEM) sample preparation for a local region of interest as it shows several potential benefits compared to conventional Ga+ FIB milling. Nevertheless, challenges and questions remain especially in terms of FIB-induced artefacts, which hinder reliable S/TEM microstructural and compositional analysis. Here we examine the efficacy of using Xe+ pFIB as compared with conventional Ga+ FIB for TEM sample preparation of Al alloys. Three potential source of specimen preparation artefacts were examined, namely: (1) implantation-induced defects such as amophisation, dislocations, or 'bubble' formation in the near-surface region resulting from ion bombardment of the sample by the incident beam; (2) compositional artefacts due to implantation of the source ions and (3) material redeposition due to the milling process. It is shown that Xe+ pFIB milling is able to produce improved STEM/TEM samples compared to those produced by Ga+ milling, and is therefore the preferred specimen preparation route. Strategies for minimising the artefacts induced by Xe+ pFIB and Ga+ FIB are also proposed. LAY DESCRIPTION: FIB (focused ion beam) instruments have become one of the most important systems in the preparation of site-specific TEM specimens, which are typically 50-100 nm in thickness. TEM specimen preparation of Al alloys is particularly challenging, as convention Ga-ion FIB produces artefacts in these materials that make microstructural analysis difficult or impossible. Recently, the use of noble gas ion sources, such as Xe, has markedly improved milling speeds and is being used for the preparation of various materials. Hence, it is necessary to investigate the structural defects formed during FIB milling and assess the ion-induced chemical contamination in these TEM samples. Here we explore the feasibility and efficiency of using Xe+ PFIB as a TEM sample preparation route for Al alloys in comparison with the conventional Ga+FIB.

17.
Parasite Immunol ; 43(10-11): e12871, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34037255

RESUMO

Gamma-delta (γδ) T cells are the bridge between natural and adaptive immunity. In the present study, peripheral blood was collected from 13 patients with advanced schistosomiasis (schistosomiasis group) and 13 uninfected people (control group) to investigate the γδ T cells and their subtypes in human schistosomiasis. Compared with the control group, the proportion of Vδ1 cells and CD27+ Vδ1+ cells in the schistosomiasis group increased significantly, while CD27- cells and CD27- Vδ1- cells decreased. Only the level of IL-17A differed between the groups, being significantly decreased in the schistosomiasis group. In the schistosomiasis group, there were no correlations between the liver fibrosis and subsets of γδ T cells, or the level of cytokines. Additionally, the level of IL-17A correlated positively with the proportion of CD27- Vδ1- cells. Thus, there was a higher frequency of circulating Vδ1 γδT cells in patients with advanced schistosomiasis. The decreased IL-17A might be related to the reduction in CD27- Vδ1- cell.


Assuntos
Receptores de Antígenos de Linfócitos T gama-delta , Esquistossomose , Citocinas , Humanos , Cirrose Hepática , Subpopulações de Linfócitos T
18.
Support Care Cancer ; 29(8): 4773-4782, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33527226

RESUMO

PURPOSE: This study aimed to examine the prevalence of psychological distress and the corresponding risk factors among patients with breast cancer affected by the outbreak of coronavirus disease 2019 (COVID-19). METHODS: This cross-sectional, survey-based, region-stratified study was conducted from March 14 to March 21, 2020. An online survey was used to collect the basic characteristics of patients with breast cancer. The degree of depression, anxiety, and insomnia symptoms were assessed using the Patient Health Questionnaire (PHQ-9), the Generalized Anxiety Disorder (GAD-7), and the Insomnia Severity Index (ISI) questionnaires, respectively. Multivariate logistic analysis was performed to identify factors associated with psychological distress outcomes. RESULTS: Among the 834 patients with breast cancer included in the study, the prevalence of depression, anxiety, and insomnia was 21.6%, 15.5%, and 14.7%, respectively. No statistically significant difference in the prevalence of these symptoms was observed between patients in Wuhan and those outside Wuhan. Multivariate logistic regression analyses revealed that comorbidity, living alone, deterioration of breast cancer, and affected treatment plan were risk factors for psychological distress including depression, anxiety, and insomnia. When stratified by location, living alone was associated with depression and insomnia only among patients in Wuhan, but not those outside Wuhan. CONCLUSIONS: This study shows an elevated prevalence of depression, anxiety, and insomnia among patients with breast cancer during part of the COVID-19 pandemic. Patients with comorbidity, living alone, deterioration of breast cancer, and whose treatment plan was affected should be paid more attention to prevent mental disorders.


Assuntos
Ansiedade , Neoplasias da Mama , COVID-19 , Depressão , Psico-Oncologia , Distúrbios do Início e da Manutenção do Sono , Ansiedade/diagnóstico , Ansiedade/epidemiologia , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/psicologia , COVID-19/epidemiologia , COVID-19/psicologia , China/epidemiologia , Estudos Transversais , Depressão/diagnóstico , Feminino , Humanos , Pessoa de Meia-Idade , Prevalência , Psico-Oncologia/métodos , Psico-Oncologia/estatística & dados numéricos , Angústia Psicológica , Fatores de Risco , SARS-CoV-2 , Distúrbios do Início e da Manutenção do Sono/diagnóstico , Distúrbios do Início e da Manutenção do Sono/epidemiologia
19.
Dig Dis Sci ; 66(7): 2272-2282, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-32749639

RESUMO

BACKGROUND: In colorectal cancer (CRC), miR-137-3p downregulation is associated with disease progression, but the mechanism is not fully understood. KDM1A, also known as LSD1, is upregulated in various cancer and promotes tumor metastasis. Interestingly, miR-137-3p is downregulated by hypoxia, which plays critical roles in tumor metastasis, and KDM1A is a miR-137-3p target gene in brain tumors. AIMS: To study if CRC metastasis is regulated by a hypoxia/miR-137-3p/KDM1A axis and if the epithelial-mesenchymal transition (EMT) process is involved. METHODS: We measured the levels of miR-137-3p, KDM1A, and some EMT markers in CRC biopsy tissues and cell lines. We also investigated the regulation of KDM1A by miR-137-3p and the effects of KDM1A inhibition on the EMT process and cell migration. RESULTS: We verified the low miR-137-3p and high KDM1A levels in CRC tumors. Inhibiting miR-137-3p upregulated KDM1A expression and promoted the invasiveness of CRC cells. KDM1A knockdown, or treatment with tranylcypromine, a specific KDM1A inhibitor, reduced the migration and invasion of CRC cells by inhibiting the EMT process. CRC cells cultured under hypoxic conditions expressed less miR-137-3p but more KDM1A than cells cultured under normal conditions, implying the involvement of miR-137-3p and KDM1A in hypoxia-induced tumor metastasis. CONCLUSIONS: We conclude that MiR-137-3p inhibits CRC cell migration by regulating a KDM1A-dependent EMT process. Our study suggests that restoring the expression of miR-137-3p or targeting KDM1A might be potential therapeutic strategies for CRC.


Assuntos
Movimento Celular/fisiologia , Neoplasias Colorretais/metabolismo , Transição Epitelial-Mesenquimal/fisiologia , MicroRNAs/metabolismo , Idoso , Adesão Celular , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Humanos , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Regulação para Cima
20.
Cell Mol Biol Lett ; 26(1): 45, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34758724

RESUMO

BACKGROUND: Liquid-liquid phase separation (LLPS) within the nucleus is directly linked to driving gene expression through transcriptional complexes. Histone lysine methyltransferase 2D (KMT2D) is widely present in many cancers. It is known to epigenetically stimulate the expression of genes associated with tumorigenesis and metastasis. Our analyses show that KMT2D possesses two distinct low-complexity domains (LCDs) capable of driving the assembly of membrane-less condensates. The dependence of the mechanisms underlying monomethylation of H3K4 on the LLPS microenvironment derived from KMT2D LCDs is unclear in tumor. METHODS: KMT2D LCD-depletion cells were used to investigate tumor cell proliferation, apoptosis, and migration. We identified some core proteins, including WDR5, RBBP5, and ASH2L, which are involved in the KMT2D-associated catalytic complex in KMT2D LCD-deficient cells to further elucidate the mechanism that decreases monomethylation of H3K4. We also evaluated the viability of KMT2D LCD-deficient cells in vivo. Finally, using 1,6-hexanediol (HD), an inhibitor of LLPS, we determined cell activities associated with KMT2D function in wild-type PANC-1 cells. RESULTS: Without the LLPS microenvironment in KMT2D LCD-deficient cells or wild-type PANC-1 cells treated with HD, the WDR5 protein was significantly less stable and the protein-protein interactions between the components of the KMT2D-enzyme complex were attenuated, impairing the formation of the complex. Moreover, with the decrease in H3K4me1 level at enhancers, transcription factors such as LIFR and KLF4 were markedly downregulated, effectively inhibiting tumor progression. In xenograft tumor models, PANC-1 cells lacking the KMT2D LCDs showed effectively suppressed tumor growth compared to normal cells. CONCLUSIONS: Our data indicate that the two low-complexity domains of the KMT2D protein could form a stable LLPS microenvironment, promoting the KMT2D catalysis of H3K4 monomethylation through stabilization of the WDR5 protein and KMT2D-enzyme complex. Therefore, finding ways to regulate the LLPS microenvironment will be benefitial for new cancer treatment strategies.


Assuntos
Proteínas de Ligação a DNA/genética , Histonas/genética , Proteínas de Neoplasias/genética , Neoplasias Pancreáticas/genética , Domínios Proteicos/genética , Transcrição Gênica/genética , Animais , Carcinogênese/genética , Linhagem Celular , Proliferação de Células/genética , Feminino , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Pancreáticas/patologia , Mapas de Interação de Proteínas/genética , Fatores de Transcrição/genética
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