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Renal ischemia-reperfusion injury (IRI) is an integral process in renal transplantation, which results in compromised graft survival. Macrophages play an important role in both the early inflammatory period and late fibrotic period in response to IRI. In this study, we investigated whether scutellarin (SCU) could protect against renal IRI by regulating macrophage polarization. Mice were given SCU (5-50 mg/kg) by gavage 1 h earlier, followed by a unilateral renal IRI. Renal function and pathological injury were assessed 24 h after reperfusion. The results showed that administration of 50 mg/kg SCU significantly improved renal function and renal pathology in IRI mice. In addition, SCU alleviated IRI-induced apoptosis. Meanwhile, it reduced macrophage infiltration and inhibited pro-inflammatory macrophage polarization. Moreover, in RAW 264.7 cells and primary bone marrow-derived macrophages (BMDMs) exposed to SCU, we found that 150 µM SCU inhibited these cells to polarize to an inflammatory phenotype induced by lipopolysaccharide (LPS) and interferon-γ (IFN-γ). However, SCU has no influence on anti-inflammatory macrophage polarization in vivo and in vitro induced by in interleukin-4 (IL-4). Finally, we explored the effect of SCU on the activation of the mitogen-activated protein kinase (MAPK) pathway both in vivo and in vitro. We found that SCU suppressed the activation of the MAPK pathway, including the extracellular signal-regulated kinase (ERK), Jun N-terminal kinase (JNK), and p38. Our results demonstrated that SCU protects the kidney against IRI by inhibiting macrophage infiltration and polarization toward pro-inflammatory phenotype via the MAPK pathway, suggesting that SCU may be therapeutically important in treatment of IRI.
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Apigenina , Glucuronatos , Sistema de Sinalização das MAP Quinases , Macrófagos , Traumatismo por Reperfusão , Animais , Masculino , Camundongos , Apigenina/farmacologia , Apoptose/efeitos dos fármacos , Glucuronatos/farmacologia , Glucuronatos/uso terapêutico , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/prevenção & controle , Inflamação/patologia , Rim/metabolismo , Rim/efeitos dos fármacos , Rim/patologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Células RAW 264.7 , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/metabolismoRESUMO
Acute myeloid leukaemia (AML) is a biologically heterogeneous disease with an overall poor prognosis; thus, novel therapeutic approaches are needed. Our previous studies showed that 4-amino-2-trifluoromethyl-phenyl retinate (ATPR), a new derivative of all-trans retinoic acid (ATRA), could induce AML cell differentiation and cycle arrest. The current study aimed to determine the potential pharmacological mechanisms of ATPR therapies against AML. Our findings showed that E2A was overexpressed in AML specimens and cell lines, and mediate AML development by inactivating the P53 pathway. The findings indicated that E2A expression and activity decreased with ATPR treatment. Furthermore, we determined that E2A inhibition could enhance the effect of ATPR-induced AML cell differentiation and cycle arrest, whereas E2A overexpression could reverse this effect, suggesting that the E2A gene plays a crucial role in AML. We identified P53 and c-Myc were downstream pathways and targets for silencing E2A cells using RNA sequencing, which are involved in the progression of AML. Taken together, these results confirmed that ATPR inhibited the expression of E2A/c-Myc, which led to the activation of the P53 pathway, and induced cell differentiation and cycle arrest in AML.
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Antineoplásicos , Leucemia Mieloide Aguda , Antineoplásicos/farmacologia , Diferenciação Celular , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Tretinoína/farmacologiaRESUMO
While trivalent chromium has been shown at high doses to have pharmacological effects improving insulin resistance in rodent models of insulin resistance, the mechanism of action of chromium at a molecular level is not known. The chromium-binding and transport agent low-molecular-weight chromium-binding substance (LMWCr) has been proposed to be the biologically active form of chromium. LMWCr has recently been shown to be comprised of a heptapeptide of the sequence EEEEDGG. The binding of Cr(3+) to this heptapeptide has been examined. Mass spectrometric and a variety of spectroscopic studies have shown that multiple chromic ions bind to the peptide in an octahedral fashion through carboxylate groups and potentially small anionic ligands such as oxide and hydroxide. A complex of Cr and the peptide when administered intravenously to mice is able to decrease area under the curve in intravenous glucose tolerance tests. It can also restore insulin-stimulated glucose uptake in myotubes rendered insulin resistant by treating them with a high-glucose media.
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Cromo/farmacologia , Oligopeptídeos/farmacologia , Animais , Células Cultivadas , Cromo/administração & dosagem , Cromo/química , Glucose/administração & dosagem , Glucose/metabolismo , Teste de Tolerância a Glucose , Injeções Intravenosas , Resistência à Insulina , Espectroscopia de Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos , Oligopeptídeos/administração & dosagem , Oligopeptídeos/química , Espectrometria de Fluorescência , Espectrofotometria InfravermelhoRESUMO
Background and aims: Obesity and insulin resistance are well-known important risk factors for hypertension. This study aimed to investigate the mediating effect of the triglyceride-glucose index (TyG) in the association between Chinese visceral obesity index (CVAI) and hypertension among Chinese middle-aged and older adults. Methods: A total of 10,322 participants aged 45 years and older from CHARLS (2011-2018) were included. Baseline data were collected in 2011 and hypertension incidence data were gathered during follow-up in 2013, 2015 and 2018. Multivariate logistic regression models were constructed to investigate the association of CVAI and TyG with the incidence of hypertension. Additionally, mediation analyses were conducted to evaluate the mediating role of the TyG index in the relationship between CVAI and hypertension. Subgroup analysis was also performed. Results: A total of 2,802 participants developed hypertension during the follow-up period. CVAI and TyG index were independently and significantly associated with hypertension incidence. Increasing quartiles of CVAI and TyG index were associated with high hypertension incidence in middle-aged and older adults. The TyG index was identified as a mediator in the relationship between CVAI and hypertension incidence, with a mediation effect (95% confidence interval) was 12.38% (6.75, 31.81%). Conclusion: Our study found that CVAI and TyG were independently associated with hypertension incidence. TyG played a partial mediating effect in the positive association between CVAI and hypertension incidence.
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Hipertensão , Resistência à Insulina , Pessoa de Meia-Idade , Humanos , Idoso , Incidência , Estudos Longitudinais , Aposentadoria , Obesidade/epidemiologia , China/epidemiologia , Glucose , Hipertensão/epidemiologia , TriglicerídeosRESUMO
Oncogene FLT3 internal tandem duplication (FLT3-ITD) mutation accounts for 30 % of acute myeloid leukaemia (AML) cases and induces transformation. Previously, we found that E2F transcription factor 1 (E2F1) was involved in AML cell differentiation. Here, we reported that E2F1 expression was aberrantly upregulated in AML patients, especially in AML patients carrying FLT3-ITD. E2F1 knockdown inhibited cell proliferation and increased cell sensitivity to chemotherapy in cultured FLT3-ITD-positive AML cells. E2F1-depleted FLT3-ITD+ AML cells lost their malignancy as shown by the reduced leukaemia burden and prolonged survival in NOD-PrkdcscidIl2rgem1/Smoc mice receiving xenografts. Additionally, FLT3-ITD-driven transformation of human CD34+ hematopoietic stem and progenitor cells was counteracted by E2F1 knockdown. Mechanistically, FLT3-ITD enhanced the expression and nuclear accumulation of E2F1 in AML cells. Further study using chromatin immunoprecipitation-sequencing and metabolomics analyses revealed that ectopic FLT3-ITD promoted the recruitment of E2F1 on genes encoding key enzymatic regulators of purine metabolism and thus supported AML cell proliferation. Together, this study demonstrates that E2F1-activated purine metabolism is a critical downstream process of FLT3-ITD in AML and a potential target for FLT3-ITD+ AML patients.
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Leucemia Mieloide Aguda , Humanos , Camundongos , Animais , Camundongos Endogâmicos NOD , Leucemia Mieloide Aguda/metabolismo , Células Cultivadas , Antígenos CD34 , Purinas , Tirosina Quinase 3 Semelhante a fms/genética , Tirosina Quinase 3 Semelhante a fms/metabolismo , Mutação , Fator de Transcrição E2F1/genéticaRESUMO
The present study aimed to better understand the possibility of utilizing all-trans retinoic acids (ATRA) in acute myeloid leukemia (AML). We found that ATRA significantly suppressed global translation and protein synthesis in AML cells. The efficacy of ATRA in treating AML required its translational regulatory functions, as shown by the fact that the decrease in the universal eukaryotic initiation factor 4E (eIF4E) was essential to maintain the induction of cell growth arrest and differentiation by ATRA. By establishing a specific translational landscape, we suggested that transcripts with simple 5'UTR gained a translational advantage in AML cells during ATRA stress. Based on that, the genes translationally regulated by ATRA were mainly enriched in phosphatidylinositol-3-kinase/Akt (PI3K/AKT) signaling; we subsequently revealed that PI3K/AKT activation was required for ATRA to effectively induce AML cell differentiation. However, PI3K/AKT has been reported to promote the stemness of AML cells. As such, we further suggested that sequential treatment including ATRA and PI3K/AKT inhibitor induced robust apoptosis, extremely inhibited the clonality of AML cells, and suppressed the FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD)-driven transformation of CD34+ hematopoietic stem/progenitor cells. Future clinical studies are warranted to further support the clinical application of the sequential strategy for the effective treatment of AML.
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The polydopamine nanoparticles (PDA NPs) as a self-polymerized form of dopamine have occurred with growing interest in biomedical applications in late years. Its natural-inspired feature as a conjugated polymer endows excellent inactivating capability for radical species to PDA-based nanoparticles that provide a theoretical foundation for applications in preventing inflammation-mediated acute kidney injury (AKI) from ROS. Here, we develop a polydopamine wrapped manganese ferrite nanoparticles (PDA@MF NPs) strategy for acute kidney injury therapy by synergistically scavenging ROS and producing O2, which further regulates macrophages amounts by decreasing M1-type and increasing M2-type. Water-soluble PDA@MF NPs were prepared in one step after the oxidative and self-polymerized process of the dopamine monomer. Here, the biodegradable PDA NPs were applied to scavenge ROS. MF NPs undertake continuous O2 production in an H2O2-based hypoxic environment. Based on this system, we aim to relieve the hypoxia, pathological symptoms, and inflammation via scavenging ROS during the O2 production process, and effective polarization to M2-type macrophages. PDA@MF NPs in this study were verified could significantly attenuate oxidative stress in vivo, reduce inflammatory events in renal, and improve renal function, which might be a potential treatment to inhibit oxidative damages and inflammatory events in renal AKI disease.
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Injúria Renal Aguda/genética , Indóis/metabolismo , Inflamação/genética , Nanopartículas/metabolismo , Estresse Oxidativo/genética , Polímeros/metabolismo , Injúria Renal Aguda/patologia , Animais , Modelos Animais de Doenças , Humanos , CamundongosRESUMO
Objective: We aimed to identify feature immune-related genes that correlated with graft rejection and to develop a prognostic model based on immune-related genes in kidney transplantation. Methods: Gene expression profiles were obtained from the GEO database. The GSE36059 dataset was used as a discovery cohort. Then, differential expression analysis and a machine learning method were performed to select feature immune-related genes. After that, univariate and multivariate Cox regression analyses were used to identify prognosis-related genes. A novel Riskscore model was built based on the results of multivariate regression. The levels of these feature genes were also confirmed in an independent single-cell dataset and other GEO datasets. Results: 15 immune-related genes were expressed differently between non-rejection and rejection kidney allografts. Those differentially expressed immune-related genes (DE-IRGs) were mainly associated with immune-related biological processes and pathways. Subsequently, a 5-immune-gene signature was constructed and showed favorable predictive results in the GSE21374 dataset. Recipients were divided into the high-risk and low-risk groups according to the median value of RiskScore. The GO and KEGG analysis indicated that the differentially expressed genes (DEGs) between high-risk and low-risk groups were mainly involved in inflammatory pathways, chemokine-related pathways, and rejection-related pathways. Immune infiltration analysis demonstrated that RiskScore was potentially related to immune infiltration. Kaplan-Meier survival analysis suggested that recipients in the high-risk group had poor graft survival. AUC values of 1- and 3-year graft survival were 0.804 and 0.793, respectively. Conclusion: Our data suggest that this immune-related prognostic model had good sensitivity and specificity in predicting the 1- and 3-year kidney graft survival and might act as a useful tool for predicting kidney graft loss.
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Regulação Neoplásica da Expressão Gênica , Transplante de Rim , Biomarcadores Tumorais/genética , Humanos , Rim , Transplante de Rim/efeitos adversos , PrognósticoRESUMO
Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by synovial hyperplasia and progressive joint destruction in the middle and late stages. Notably, activated rheumatoid arthritis synovial fibroblasts (RASFs) exhibit tumor-like features, including an increased proliferation rate that largely contributes to pannus formation and joint destruction. Our previous studies have demonstrated that acid-sensing ion channel 1a (ASIC1a) was highly expressed in RASFs, and acidic microenvironment of synovial fluid in patients with RA can activate ASIC1a to promote synovial inflammation, leading to the progression of RA. However, the role and possible mechanism of ASIC1a in RASF proliferation remains unclear. The present study aimed to investigate the effect of ASIC1a activation upon acidosis on RASF proliferation and its molecular mechanism in vivo and in vitro. The results of in vitro experiments showed that activation of ASIC1a upon acidosis promoted the proliferation of RASFs, which could be attenuated by the specific ASIC1a inhibitor Psalmotoxin-1 (PcTx-1) or specific siRNA for ASIC1a. Mechanistically, Wnt/ß-catenin/c-Myc signaling pathway was involved in ASIC1a-induced RASF proliferation. The results of in vivo experiments indicated that intra-articular injection of PcTx-1 reduced synovial hyperplasia and ameliorated cartilage degradation in rats with adjuvant arthritis (AA). Collectively, these results suggest that activation of ASIC1a upon acidosis promotes RASF proliferation, and the mechanism may be related to Wnt/ß-catenin/c-Myc pathway.
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Canais Iônicos Sensíveis a Ácido , Acidose , Artrite Reumatoide , Animais , Ratos , Canais Iônicos Sensíveis a Ácido/genética , Canais Iônicos Sensíveis a Ácido/metabolismo , Acidose/metabolismo , Acidose/patologia , Artrite Reumatoide/genética , beta Catenina/metabolismo , Cateninas/metabolismo , Cateninas/farmacologia , Proliferação de Células , Células Cultivadas , Fibroblastos , Hiperplasia/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Membrana Sinovial/patologia , Via de Sinalização WntRESUMO
Mantle cell lymphoma (MCL) is a lymphoproliferative disorder that lacks reliable therapeutic options. Therefore, new treatment approaches for targeting novel biological pathways are required. 4-amino-2-trifluoromethyl-phenyl retinate (ATPR) synthesized by our group previously has been proven to have higher solubility and superior differentiation effects compared to those of conventional all-trans retinoic acid in acute myeloid leukemia. ATPR induces differentiation and inhibits the proliferation of acute promyelocytic leukemia. However, whether ATPR induces differentiation of MCL cells to normal immune cells has not been investigated. In this study, the proliferation of JEKO-1 cells was completely repressed, and differentiation was activated after ATPR treatment. The neural transcription factor SOX11 was further found to be highly expressed in MCL, but was downregulated by ATPR. After silencing SOX11 in vitro and in vivo, the malignant proliferation and inhibited differentiation of JEKO-1 cells were reversed, whereas the overexpression of SOX11 exacerbated the malignant phenotype of JEKO-1 cells. We also have added additional MCL cell lines (MINO) to complete the key pilot experiments. In addition, the CyclinD1/Rb/E2F1 axis was involved in MCL and was regulated by ATPR. In conclusion, ATPR promoted JEKO-1 cell differentiation via SOX11/CyclinD1/Rb/E2F1. This study provides experimental foundation for developing differentiation therapy for MCL with ATPR.
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Leucemia Promielocítica Aguda , Linfoma de Célula do Manto , Retinoides/farmacologia , Adulto , Diferenciação Celular , Linhagem Celular Tumoral , Proliferação de Células , Fator de Transcrição E2F1 , Humanos , Leucemia Promielocítica Aguda/metabolismo , Fatores de Transcrição SOXC/genética , Fatores de Transcrição SOXC/metabolismo , Fatores de Transcrição SOXC/farmacologiaRESUMO
OBJECTIVES: This study aimed to investigate the biological impacts and possible mechanisms of a novel lncRNA, LncSIK1, in AML progression and retinoic acid-regulated AML cell development. MATERIALS AND METHODS: The expression pattern of LncSIK1 was evaluated by qPCR and fluorescence in situ hybridization. CCK-8 assay, immunofluorescence, Wright-Giemsa staining, flow cytometry and Western blotting were performed to assess cell proliferation and differentiation. Bioluminescence imaging and H&E staining were used to detect AML progression in vivo. RNA or chromatin immunoprecipitation assays were conducted to measure the interaction of E2F1 and LncSIK1 or the LC3 and DRAM promoters. Autophagy was measured by transmission electron microscopy and Western blotting. RESULTS: LncSIK1 was silenced in bone marrow mononuclear cells from AML patients compared with those from healthy donors. LncSIK1 strengthened the effect of retinoic acid in inducing cell differentiation and inhibiting cell proliferation in AML cells. Moreover, the silencing of LncSIK1 was critical to maintaining AML leukaemogenesis, as LncSIK1 enhancement retarded AML progression in vivo. Mechanistically, in NB4 cells, LncSIK1 recruited the E2F1 protein to the promoters of LC3 and DRAM and induced autophagy-dependent degradation of the oncoprotein PML-RARa. However, LncSIK1 blocked E2F1 expression and the E2F1-mediated transcription of LC3 and DRAM, thereby relieving aggressive autophagy in Molm13 cells. CONCLUSIONS: Taken together, these data indicated that LncSIK1 was an important regulator of AML development through regulating the E2F1/autophagy signalling pathway.
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Autofagia/efeitos dos fármacos , Fator de Transcrição E2F1/efeitos dos fármacos , RNA Longo não Codificante/genética , Tretinoína/farmacologia , Animais , Antineoplásicos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Fator de Transcrição E2F1/metabolismo , Humanos , Leucemia Mieloide Aguda/metabolismo , Camundongos TransgênicosRESUMO
4-Amino-2-Trifluoromethyl-Phenyl Retinate (ATPR), a novel all-trans retinoic acid (ATRA) derivative, has been demonstrated that it had a variety of anti-tumor effects by exerting regulation on cellular proliferation, apoptosis and differentiation. Here, we found that ATPR is critical for alleviating myelodysplastic syndrome (MDS) and acute myelogenous leukemia. USO1, vesicle transport factor, belongs to tether protein family and involved in endoplasmic reticulum to Golgi trafficking of protein which is important to tumorigenesis. How USO1 contribute to MDS remain elusive. USO1 is aberrantly activated in MDS and AML in vivo and vitro, aberration of which might be a dominant mechanism for MDS cell survival. During the ATPR-induced remission of MDS, in vitro, USO1 presents a time and concentration-dependent decrease. Silencing of USO1 promotes myeloid differentiation of MDS cells and inhibits MDS cellular proliferation while USO1 over-expression has the opposite effect, suggesting that reduction of USO1 enhances the sensitivity of SKM-1 cells to ATPR treatment. Mechanistically, USO1 exerts its oncogenic role by inactivating Raf/ERK signaling, while ATPR is access to revise it. Notably, the activity of Raf/ERK pathway is required for the development and maintenance of MDS cell proliferation. Collectively, our results demonstrate the USO1- Raf/ERK signaling axis in MDS and highlight the negative role of USO1 in ATPR-regulated remission of MDS.
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Proteínas da Matriz do Complexo de Golgi/antagonistas & inibidores , Síndromes Mielodisplásicas/tratamento farmacológico , Retinoides/farmacologia , Proteínas de Transporte Vesicular/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Proteínas da Matriz do Complexo de Golgi/genética , Proteínas da Matriz do Complexo de Golgi/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Síndromes Mielodisplásicas/patologia , Retinoides/uso terapêutico , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismoRESUMO
Epidemiological data suggest that the incidence of rheumatoid arthritis (RA) increases in postmenopausal women, which may be related to estrogen deficiency. Tissue acidosis is a common symptom of RA. Acid-sensitive ion channel 1a (ASIC1a), a member of the extracellular H+-activated cation channel family, could be activated by changes in extracellular pH and plays a crucial role in the pathogenesis of RA. As the only cellular component in cartilage tissue, chondrocytes play an extremely important role in maintaining cartilage tissue homeostasis. The aim of this study was to investigate whether estrogen could protect acid-stimulated chondrocytes by regulating the expression of ASIC1a and explore the possible mechanism. The results showed that estrogen could protect against acid-induced chondrocyte injury by reducing ASIC1a protein expression. Moreover, lysosome inhibitor chloroquine (CQ) and autophagy inhibitor 3-methyladeniine (3-MA) could reverse the reduction of ASIC1a protein caused by estrogen, indicating that autophagy-lysosome pathway contributes to estrogen-induced degradation of ASIC1a protein. Furthermore, the down-regulation of ASIC1a expression by estrogen was attenuated by MPP, a specific inhibitor of estrogen-related receptor-alpha (Esrra), indicating that Esrra is involved in the process of estrogen regulating the expression of ASIC1a. Additionally, adenosine 5'-monophosphate (AMP)-activated protein kinase/unc-51-like kinase 1 (AMPK-ULK1) signaling pathway was activated by estrogen treatment, which was abrogated by Esrra-silencing, and AMPK-specific inhibitor Compound C pretreatment could reduce estrogen-induced downregulation of ASIC1a protein. Taken together, these results indicate that estrogen could promote autophagy-lysosome pathway-dependent ASIC1a protein degradation and protect against acidosis-induced cytotoxicity, the mechanisms of which might relate to Esrra-AMPK-ULK1 signaling pathway.
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Condrócitos , Canais Iônicos Sensíveis a Ácido , Acidose , Animais , Cartilagem Articular , Humanos , Proteólise , RatosRESUMO
Current wearable sensors are fabricated with substrates, which limits the comfort, flexibility, stretchability, and induces interface mismatch. In addition, the substrate prevents the evaporation of sweat and is harmful to skin health. In this work, we have enabled the substrate-free laser scribed graphene (SFG) electronic skin (e-skin) with multifunctions. Compared with the e-skin with the substrate, the SFG has good gas permeability, low impedance, and flexibility. Only assisted using water, the SFG can be transferred to almost any objects including silicon and human skin and it can even be suspended. Many through-holes like stomas in leaf can be formed in the SFG, which make it breathable. After designing the pattern, the gauge factor (GF) of graphene electronic skin (GES) can be designed as the strain sensor. Physiological signals such as respiration, human motion, and electrocardiogram (ECG) can be detected. Moreover, the suspended SFG detect vibrations with high sensitivity. Due to the substrate-free structure, the impedance between SFG e-skin and the human body decreases greatly. Finally, an ECG detecting system has been designed based on the GES, which can monitor the body condition in real time. To analyze the ECG signals automatically, a convolutional neural network (CNN) was built and trained successfully. This work has high potential in the field of health telemonitoring.
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Inteligência Artificial , Grafite/química , Dispositivos Eletrônicos Vestíveis , Humanos , Tamanho da Partícula , Propriedades de SuperfícieRESUMO
The flexible pressure sensor is one of the essential components of the wearable device, which is a critical solution to the applications of artificial intelligence and human-computer interactions in the future. Due to its simple manufacturing process and measurement methods, research related to piezoresistive mechanical sensors is booming, and those sensors are already widely used in industry. However, existing pressure sensors are almost all based on negative resistance variations, making it difficult to reach a balance between the sensitivity and the detection range. Here, we demonstrated a low-cost flexible pressure sensor with a positive resistance-pressure response based on laser scribing graphene. The sensor can be customized and modulated to achieve both an ultrahigh sensitivity and a broad detection range. Furthermore, the device possesses the signal amplification property like a mechanical triode under the external pressure bias. Based on its amplification ability, varieties of physiological signals and human movements have been detected using our devices; then, an integrated gait monitoring system has been realized. The reported positive graphene pressure sensor has outstanding capability, showing a wide application range such as intelligent perception, an interactive device, and real-time health/motion monitoring.
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Grafite , Dispositivos Eletrônicos Vestíveis , Inteligência Artificial , Humanos , Monitorização Fisiológica , Movimento (Física)RESUMO
The human body is a "delicate machine" full of sensors such as the fingers, nose, and mouth. In addition, numerous physiological signals are being created every moment, which can reflect the condition of the body. The quality and the quantity of the physiological signals are important for diagnoses and the execution of therapies. Due to the incompact interface between the sensors and the skin, the signals obtained by commercial rigid sensors do not bond well with the body; this decreases the quality of the signal. To increase the quantity of the data, it is important to detect physiological signals in real time during daily life. In recent years, there has been an obvious trend of applying graphene devices with excellent performance (flexibility, biocompatibility, and electronic characters) in wearable systems. In this review, we will first provide an introduction about the different methods of synthesis of graphene, and then techniques for graphene patterning will be outlined. Moreover, wearable graphene sensors to detect mechanical, electrophysiological, fluid, and gas signals will be introduced. Finally, the challenges and prospects of wearable graphene devices will be discussed. Wearable graphene sensors can improve the quality and quantity of the physiological signals and have great potential for health-care and telemedicine in the future.
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Grafite/química , Dispositivos Eletrônicos Vestíveis , Líquidos Corporais/química , Eletroencefalografia , Eletromiografia , Gases/análise , Grafite/síntese química , Humanos , Lasers , Movimento , Gases em Plasma/químicaRESUMO
A sustainable strategy by internally recycling an organocatalyst as a reactant in a downstream reaction to improve the atom efficiency of organocatalytic tandem reactions is described. Specifically, a one-pot tandem Cloke-Wilson/Boulton-Katritzky reaction of cyclopropylketones with a hydroxylamine has been developed for the synthesis of fully substituted isoxazoles, in which the hydroxylamine serves as both an upstream catalyst and a downstream reactant.
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It is crucial to dynamically analyze the movement of neutrophils (a type of white cell) during the process of inflammation. However, manually tracking and analyzing the cells is a time-consuming task due to the large volume of cells and similar appearance. To facilitate neutrophils analysis and address the issues mentioned above, we propose to leverage high-order temporal information as a cue to track neutrophils. A tensor-based approach is introduced to encode the high-order motion pattern and appearance variation for multi-frame multicell association. To evaluate the proposed method, we collected 354 sequences of cells from 200 frames of microscopic images. We conduct a systematic study on the collected data and show significant performance improvement over other solutions.
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Neutrófilos/citologia , Algoritmos , Movimento CelularRESUMO
Mongolian pine plantations (MPPs) composed of Pinus sylvestris var. mongolica (P. sylvestris) are used for desertification control and restoration of degraded land in arid and semi-arid regions. We studied soil changes associated with P. sylvestris by comparing top (0-20 cm) and sub-top (20-40 cm) soil properties across 8 stand density gradients of MPPs ranging from 900 ± 5-2700 ± 50 trees ha-1. The study was conducted in the uncovered Sandy Land in the southern Mu Us Desert, China. The relationships between the volume fractal dimensions (D) of soil particle size distribution and soil physicochemical properties were evaluated. D was determined using a laser diffraction technique and soil properties were measured. In the top layer, P. sylvestris significantly positively affected soil physicochemical properties except for bulk density and total nitrogen. These effects were not observed in the sub-top soil layer. D values ranged from 1.52 ± 0.29-2.08 ± 0.06 and were significantly correlated with stand density. Significant correlations were observed between D and soil properties (except total nitrogen) in the top soil layer. Given these results, we concluded that D is a sensitive and useful index because it quantifies changes in soil properties that additionally implies desertification in the studied area.
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Background Dexmedetomidine (DEX), an α2-adrenergic receptor agonist, produces ideal sedation and early postoperative recovery for premedication in paediatric surgery, reducing preoperative anxiety and facilitating smooth induction of anaesthesia. We performed a meta-analysis to compare the effects of DEX and midazolam (MDZ) in paediatric anaesthesia with sevoflurane. Methods PubMed, Ovid, Web of Science, and Public Health Management Corporation were searched through December 2016 for randomized controlled trials (RCTs) that compared DEX and MDZ in children undergoing sevoflurane anaesthesia. The risk ratio (RR) with 95% incidence interval (95%CI) was used for dichotomous variables. Results Twelve RCTs involving 422 patients in the DEX group and 448 patients in the MDZ group were included. Patients in the DEX group had a significantly lower incidence of unsatisfactory sedation (RR [95%CI] = 0.71 [0.57-0.89]), unsatisfactory parental separation (RR [95%CI] = 0.56 [0.35-0.87]), and rescue analgesia (RR [95%CI] = 0.52 [0.35-0.77]) than patients in the MDZ group. However, both groups had a similar incidence of unsatisfactory mask acceptance, emergence agitation, and postoperative nausea and vomiting. Conclusion Compared with MDZ, DEX is beneficial in paediatric anaesthesia with sevoflurane because of its lower incidence of unsatisfactory sedation, parental separation, and rescue analgesia.