Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 156
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 562(7725): 150, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29973715

RESUMO

Change History: This Article has been retracted; see accompanying Retraction. Corrected online 20 January: In this Article, author Frank Rigo was incorrectly listed with a middle initial; this has been corrected in the online versions of the paper.

2.
Int J Mol Sci ; 25(3)2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38338668

RESUMO

Non-alcoholic steatohepatitis (NASH) is an inflammatory form of non-alcoholic fatty liver disease (NAFLD), closely associated with disease progression, cirrhosis, liver failure, and hepatocellular carcinoma. Time-restricted feeding (TRF) has been shown to decrease body weight and adiposity and improve metabolic outcomes; however, the effect of TRF on NASH has not yet been fully understood. We had previously reported that inositol polyphosphate multikinase (IPMK) mediates hepatic insulin signaling. Importantly, we have found that TRF increases hepatic IPMK levels. Therefore, we investigated whether there is a causal link between TRF and IPMK in a mouse model of NASH, i.e., methionine- and choline-deficient diet (MCDD)-induced steatohepatitis. Here, we show that TRF alleviated markers of NASH, i.e., reduced hepatic steatosis, liver triglycerides (TG), serum alanine transaminase (ALT) and aspartate aminotransferase (AST), inflammation, and fibrosis in MCDD mice. Interestingly, MCDD led to a significant reduction in IPMK levels, and the deletion of hepatic IPMK exacerbates the NASH phenotype induced by MCDD, accompanied by increased gene expression of pro-inflammatory chemokines. Conversely, TRF restored IPMK levels and significantly reduced gene expression of proinflammatory cytokines and chemokines. Our results demonstrate that TRF attenuates MCDD-induced NASH via IPMK-mediated changes in hepatic steatosis and inflammation.


Assuntos
Deficiência de Colina , Hepatopatia Gordurosa não Alcoólica , Camundongos , Animais , Hepatopatia Gordurosa não Alcoólica/metabolismo , Metionina/metabolismo , Colina/metabolismo , Deficiência de Colina/complicações , Deficiência de Colina/metabolismo , Fígado/metabolismo , Racemetionina/metabolismo , Dieta , Inflamação/metabolismo , Quimiocinas/metabolismo , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças
3.
Can Vet J ; 65(6): 553-558, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38827592

RESUMO

Gastrointestinal stromal tumors arising from gastric cardia are uncommon in dogs. A few studies have shown the effectiveness of tyrosine kinase inhibitors in the treatment of canine gastrointestinal stromal tumors, but no standardized protocols are currently available. An 11-year-old spayed female Maltese dog was diagnosed with a gastrointestinal stromal tumor using histopathological and immunohistochemical analyses. An adenosine triphosphate-based tumor chemosensitivity assay revealed that imatinib at lower concentrations had a stronger inhibitory effect than toceranib. Based on the results of the assay, the dog was treated with imatinib after surgery. After 28 mo of therapy, there was no recurrence of the tumor. Key clinical message: Adenosine triphosphate-based tumor chemosensitivity assays may help clinicians to select appropriate postoperative chemotherapeutic drugs for incompletely resected gastrointestinal stromal tumors in dogs.


Gestion réussie à la suite d'une résection incomplète d'une tumeur stromale gastro-intestinale à l'aide de l'imatinib basée sur un test de sensibilité tumorale à base d'adénosine triphosphate chez un chien. Les tumeurs stromales gastro-intestinales résultant du cardia gastrique sont rares chez le chien. Quelques études ont montré l'efficacité des inhibiteurs de la tyrosine kinase dans le traitement des tumeurs stromales gastrointestinales canines, mais aucun protocole standardisé n'est actuellement disponible. Une chienne maltaise stérilisée de 11 ans a reçu un diagnostic de tumeur stromale gastro-intestinale à l'aide d'analyses histopathologiques et immunohistochimiques. Un test de chimiosensibilité tumorale à base d'adénosine triphosphate a révélé que l'imatinib à des concentrations plus faibles avait un effet inhibiteur plus fort que le tocéranib. Sur la base des résultats du test, le chien a été traité avec de l'imatinib après l'opération. Après 28 mois de traitement, il n'y a eu aucune récidive de la tumeur.Message clinique clé :Les tests de chimiosensibilité tumorale à base d'adénosine triphosphate peuvent aider les cliniciens à sélectionner les médicaments chimiothérapeutiques postopératoires appropriés pour les tumeurs stromales gastro-intestinales incomplètement réséquées chez le chien.(Traduit par Dr Serge Messier).


Assuntos
Antineoplásicos , Doenças do Cão , Tumores do Estroma Gastrointestinal , Mesilato de Imatinib , Animais , Tumores do Estroma Gastrointestinal/veterinária , Tumores do Estroma Gastrointestinal/cirurgia , Tumores do Estroma Gastrointestinal/tratamento farmacológico , Tumores do Estroma Gastrointestinal/patologia , Cães , Mesilato de Imatinib/uso terapêutico , Doenças do Cão/tratamento farmacológico , Doenças do Cão/cirurgia , Feminino , Antineoplásicos/uso terapêutico , Trifosfato de Adenosina/uso terapêutico , Indóis , Pirróis
4.
J Cell Biochem ; 124(11): 1695-1704, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37795573

RESUMO

Insulin resistance is a critical mediator of the development of nonalcoholic fatty liver disease (NAFLD). An excess influx of fatty acids to the liver is thought to be a pathogenic cause of insulin resistance and the development of NAFLD. Although elevated levels of free fatty acids (FFA) in plasma contribute to inducing insulin resistance and NAFLD, the molecular mechanism is not completely understood. This study aimed to determine whether inositol polyphosphate multikinase (IPMK), a regulator of insulin signaling, plays any role in FFA-induced insulin resistance in primary hepatocytes. Here, we show that excess FFA decreased IPMK expression, and blockade of IPMK decrease attenuated the FFA-induced suppression of protein kinase B (Akt) phosphorylation in primary mouse hepatocytes (PMH). Moreover, overexpression of IPMK prevented the FFA-induced suppression of Akt phosphorylation by insulin, while knockout of IPMK exacerbated insulin resistance in PMH. In addition, treatment with MG132, a proteasomal inhibitor, inhibits FFA-induced decrease in IPMK expression and Akt phosphorylation in PMH. Furthermore, treatment with the antioxidant N-acetyl cysteine (NAC) significantly attenuated the FFA-induced reduction of IPMK and restored FFA-induced insulin resistance in PMH. In conclusion, our findings suggest that excess FFA reduces IPMK expression and contributes to the FFA-induced decrease in Akt phosphorylation in PMH, leading to insulin resistance. Our study highlights IPMK as a potential therapeutic target for preventing insulin resistance and NAFLD.


Assuntos
Resistência à Insulina , Hepatopatia Gordurosa não Alcoólica , Camundongos , Animais , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ácidos Graxos não Esterificados/farmacologia , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Insulina/farmacologia , Hepatócitos/metabolismo
5.
Am J Transplant ; 23(8): 1102-1115, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36878433

RESUMO

Damage to the gastrointestinal tract following allogeneic hematopoietic stem cell transplantation is a significant contributor to the severity and perpetuation of graft-versus-host disease. In preclinical models and clinical trials, we showed that infusing high numbers of regulatory T cells reduces graft-versus-host disease incidence. Despite no change in in vitro suppressive function, transfer of ex vivo expanded regulatory T cells transduced to overexpress G protein-coupled receptor 15 or C-C motif chemokine receptor 9, specific homing receptors for colon or small intestine, respectively, lessened graft-versus-host disease severity in mice. Increased regulatory T cell frequency and retention within the gastrointestinal tissues of mice that received gut homing T cells correlated with lower inflammation and gut damage early post-transplant, decreased graft-versus-host disease severity, and prolonged survival compared with those receiving control transduced regulatory T cells. These data provide evidence that enforced targeting of ex vivo expanded regulatory T cells to the gastrointestinal tract diminishes gut injury and is associated with decreased graft-versus-host disease severity.


Assuntos
Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Animais , Camundongos , Linfócitos T Reguladores , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/prevenção & controle , Doença Enxerto-Hospedeiro/tratamento farmacológico , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Intestino Delgado , Inflamação
6.
Environ Res ; 231(Pt 3): 116266, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37257744

RESUMO

In this study, the feasibility of Mg/Al layered double hydroxides (LDH) functionalized coffee ground waste biochars (LDHMgAl@CWGB) as a potential adsorbent to selectively recover phosphate (PO43-) and nitrate (NO3-) ions in aqueous phases and their consecutive uses as a slow-release fertilizer for stimulating the plant growth were identified. The higher adsorption capacity of PO43- and NO3- ions by LDHMgAl@CWGB (PO43- = 6.98 mgP/g, NO3- = 2.82 mgN/g) compared with pristine coffee ground waste biochars (CWGB; PO43- = 0.19 mgP/g, NO3- = 0.32 mgN/g) was mainly due to the incorporation of Mg/Al mixed oxides and Cl contents. Chemisorption and intra-particle mainly controlled the adsorptive recovery of PO43- and NO3- ions by CWGB and LDHMgAl@CWGB in aqueous phases and their adsorption toward CWGB and LDHMgAl@CWGB proceeded endothermically and spontaneously. The changes in the major adsorption mechanisms of PO43- and NO3- ions from ligand exchange (CWGB) to electrostatic surface complexation and anion-exchange (LDHMgAl@CWGB) supported the conclusion that the alternation of the surface features through Mg/Al LDH functionalization might improve selectivity and adsorption capacity of PO43- and NO3- ions onto CWGB under the co-existence of Cl-, SO42-, and HCO3- ions. Since PO43-- and NO3--loaded LDHMgAl@CWGB exhibited much higher seed germination, root and shoot growth rates of garden cress seeds (Lepidium sativum L) than other liquid and solid matrices, including 5 mgP/L PO43- and 5 mgN/L NO3-, 10 mgP/L PO43- and 10 mgN/L NO3-, and LDHMgAl@CWGB, it can be postulated that PO43-- and NO3--loaded LDHMgAl@CWGB could be practically applicable to the agricultural field as a slow-release fertilizer to facilitate the seed germination, root and shoot growth of the plants.


Assuntos
Nitratos , Fosfatos , Fertilizantes , Café , Hidróxidos , Água , Adsorção , Cinética
7.
Cryobiology ; 111: 142-145, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37001845

RESUMO

The CryoPreservation Media (CPM) for mouse sperm using raffinose and skim milk have been improved by adding either monothioglycerol (MTG) or l-glutamine to reduce the oxidative damage during sperm freezing and thawing. The CARD-CPM utilizing l-glutamine, but not MTG, has been widely used to meet the rising demand for cryopreservation of genetically modified mice, as the CARD method also improved sperm capacitation and in vitro fertilization (IVF). However, the viability of sperm frozen in the CARD-CPM is highly variable, indicating a room for improvement. To develop a more dependable technique for mouse sperm cryopreservation, we investigate whether combining MTG and l-glutamine in the CPM (MG-CPM) can produce a synergistic impact on sperm thawing and IVF rate. We found that MG-CPM reduced the incidence of infertility and increased the IVF success rate. Therefore, cryopreservation of mouse sperm in MG-CPM is a reliable method to ensure embryo generation from frozen sperm.


Assuntos
Criopreservação , Glutamina , Camundongos , Masculino , Animais , Criopreservação/métodos , Glutamina/farmacologia , Crioprotetores/farmacologia , Camundongos Endogâmicos C57BL , Sêmen , Espermatozoides
8.
J Infect Dis ; 226(9): 1626-1636, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-35512127

RESUMO

BACKGROUND: Antiretroviral therapy (ART) containing integrase strand transfer inhibitors (INSTIs) has been associated with weight gain in both ART initiation and switch studies, especially in women, but the underlying mechanisms are unclear. METHODS: The effects of dolutegravir (DTG) on food intake, energy expenditure, oxygen consumption in female mice, and gene expression from adipose tissues were assessed. Human and murine preadipocytes were treated with DTG either during differentiation into mature brown/beige adipocytes or postdifferentiation. Lipid accumulation, lipolysis, ß-adrenergic response, adipogenic markers, mitochondrial respiration, and insulin response were analyzed. RESULTS: Two-week administration of DTG to female mice reduced energy expenditure, which was accompanied by decreased uncoupling protein 1 (UCP1) expression in brown/beige adipose tissues. In vitro studies showed that DTG significantly reduced brown adipogenic markers, especially UCP1 in brown and beige adipocytes, whereas drugs from other classes did not. Furthermore, a loss of UCP1 by DTG led to a decrease in mitochondrial complex IV component, followed by a reduction in mitochondrial respiratory capacity and reduced insulin-stimulated glucose uptake. CONCLUSIONS: Our findings show that DTG targets UCP1 and mitochondrial functions in brown and beige adipocytes and disrupts thermogenic functions in preclinical models, providing the potential mechanisms by which DTG suppresses energy expenditure leading to weight gain.


Assuntos
Adipócitos Bege , Insulinas , Feminino , Humanos , Camundongos , Animais , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo , Adipócitos Bege/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Canais Iônicos/genética , Canais Iônicos/metabolismo , Termogênese/genética , Mitocôndrias/metabolismo , Metabolismo Energético/fisiologia , Aumento de Peso , Insulinas/metabolismo
9.
J Cell Physiol ; 237(8): 3421-3432, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35822903

RESUMO

Hepatic glucose production (HGP) is crucial for the maintenance of normal glucose homeostasis. Although hepatic insulin resistance contributes to excessive glucose production, its mechanism is not well understood. Here, we show that inositol polyphosphate multikinase (IPMK), a key enzyme in inositol polyphosphate biosynthesis, plays a role in regulating hepatic insulin signaling and gluconeogenesis both in vitro and in vivo. IPMK-deficient hepatocytes exhibit decreased insulin-induced activation of Akt-FoxO1 signaling. The expression of messenger RNA levels of phosphoenolpyruvate carboxykinase 1 (Pck1) and glucose 6-phosphatase (G6pc), key enzymes mediating gluconeogenesis, are increased in IPMK-deficient hepatocytes compared to wild type hepatocytes. Importantly, re-expressing IPMK restores insulin sensitivity and alleviates glucose production in IPMK-deficient hepatocytes. Moreover, hepatocyte-specific IPMK deletion exacerbates hyperglycemia and insulin sensitivity in mice fed a high-fat diet, accompanied by an increase in HGP during pyruvate tolerance test and reduction in Akt phosphorylation in IPMK deficient liver. Our results demonstrate that IPMK mediates insulin signaling and gluconeogenesis and may be potentially targeted for treatment of diabetes.


Assuntos
Glucose , Resistência à Insulina , Insulina , Fígado , Fosfotransferases (Aceptor do Grupo Álcool) , Animais , Proteína Forkhead Box O1/metabolismo , Glucose/metabolismo , Glucose-6-Fosfatase/metabolismo , Hepatócitos/metabolismo , Insulina/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fígado/metabolismo , Camundongos , Fosfoenolpiruvato Carboxiquinase (GTP)/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo
10.
Sensors (Basel) ; 22(10)2022 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-35632135

RESUMO

In recent image classification approaches, a vision transformer (ViT) has shown an excellent performance beyond that of a convolutional neural network. A ViT achieves a high classification for natural images because it properly preserves the global image features. Conversely, a ViT still has many limitations in facial expression recognition (FER), which requires the detection of subtle changes in expression, because it can lose the local features of the image. Therefore, in this paper, we propose Squeeze ViT, a method for reducing the computational complexity by reducing the number of feature dimensions while increasing the FER performance by concurrently combining global and local features. To measure the FER performance of Squeeze ViT, experiments were conducted on lab-controlled FER datasets and a wild FER dataset. Through comparative experiments with previous state-of-the-art approaches, we proved that the proposed method achieves an excellent performance on both types of datasets.


Assuntos
Reconhecimento Facial , Redes Neurais de Computação , Projetos de Pesquisa
11.
Int J Mol Sci ; 23(12)2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35743190

RESUMO

All cells rely on nutrients to supply energy and carbon building blocks to support cellular processes. Over time, eukaryotes have developed increasingly complex systems to integrate information about available nutrients with the internal state of energy stores to activate the necessary processes to meet the immediate and ongoing needs of the cell. One such system is the network of soluble and membrane-associated inositol phosphates that coordinate the cellular responses to nutrient uptake and utilization from growth factor signaling to energy homeostasis. In this review, we discuss the coordinated interactions of the inositol polyphosphates, inositol pyrophosphates, and phosphoinositides in major metabolic signaling pathways to illustrate the central importance of the inositol phosphate signaling network in nutrient responses.


Assuntos
Fosfatos de Inositol , Polifosfatos , Transporte Biológico , Homeostase , Fosfatos de Inositol/metabolismo , Polifosfatos/metabolismo , Transdução de Sinais
12.
Int J Mol Sci ; 24(1)2022 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-36613626

RESUMO

Beyond the influence of lifestyle-related risk factors for myocardial infarction (MI), the mechanisms of genetic predispositions for MI remain unclear. We sought to identify and characterize differentially expressed genes in early-onset MI in a translational approach. In an observational case−control study, transcriptomes from 112 early-onset MI individuals showed upregulated G protein-coupled receptor 15 (GPR15) expression in peripheral blood mononuclear cells compared to controls (fold change = 1.4, p = 1.87 × 10−7). GPR15 expression correlated with intima-media thickness (ß = 0.8498, p = 0.111), C-reactive protein (ß = 0.2238, p = 0.0052), ejection fraction (ß = −0.9991, p = 0.0281) and smoking (ß = 0.7259, p = 2.79 × 10−10). The relation between smoking and MI was diminished after the inclusion of GPR15 expression as mediator in mediation analysis (from 1.27 (p = 1.9 × 10−5) to 0.46 (p = 0.21)). The DNA methylation of two GPR15 sites was 1%/5% lower in early-onset MI individuals versus controls (p = 2.37 × 10−6/p = 0.0123), with site CpG3.98251219 significantly predicting risk for incident MI (hazard ratio = 0.992, p = 0.0177). The nucleotide polymorphism rs2230344 (C/T) within GPR15 was associated with early-onset MI (odds ratio = 3.61, p = 0.044). Experimental validation showed 6.3-fold increased Gpr15 expression in an ischemic mouse model (p < 0.05) and 4-fold increased Gpr15 expression in cardiomyocytes under ischemic stress (p < 0.001). After the induction of MI, Gpr15gfp/gfp mice showed lower survival (p = 0.042) and deregulated gene expression for response to hypoxia and signaling pathways. Using a translational approach, our data provide evidence that GPR15 is linked to cardiovascular diseases, mediating the adverse effects of smoking.


Assuntos
Infarto do Miocárdio , Receptores Acoplados a Proteínas G , Fumar , Animais , Camundongos , Espessura Intima-Media Carotídea , Estudos de Casos e Controles , Leucócitos Mononucleares/metabolismo , Infarto do Miocárdio/genética , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Fumar/efeitos adversos
13.
Nature ; 528(7583): 517-22, 2015 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-26675721

RESUMO

T helper 17 (TH17) lymphocytes protect mucosal barriers from infections, but also contribute to multiple chronic inflammatory diseases. Their differentiation is controlled by RORγt, a ligand-regulated nuclear receptor. Here we identify the RNA helicase DEAD-box protein 5 (DDX5) as a RORγt partner that coordinates transcription of selective TH17 genes, and is required for TH17-mediated inflammatory pathologies. Surprisingly, the ability of DDX5 to interact with RORγt and coactivate its targets depends on intrinsic RNA helicase activity and binding of a conserved nuclear long noncoding RNA (lncRNA), Rmrp, which is mutated in patients with cartilage-hair hypoplasia. A targeted Rmrp gene mutation in mice, corresponding to a gene mutation in cartilage-hair hypoplasia patients, altered lncRNA chromatin occupancy, and reduced the DDX5-RORγt interaction and RORγt target gene transcription. Elucidation of the link between Rmrp and the DDX5-RORγt complex reveals a role for RNA helicases and lncRNAs in tissue-specific transcriptional regulation, and provides new opportunities for therapeutic intervention in TH17-dependent diseases.


Assuntos
RNA Helicases DEAD-box/metabolismo , RNA Longo não Codificante/metabolismo , Células Th17/imunologia , Células Th17/metabolismo , Animais , Cromatina/genética , Cromatina/metabolismo , RNA Helicases DEAD-box/genética , Feminino , Regulação da Expressão Gênica/genética , Cabelo/anormalidades , Doença de Hirschsprung/genética , Humanos , Síndromes de Imunodeficiência/genética , Inflamação/imunologia , Inflamação/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mutação/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Especificidade de Órgãos , Osteocondrodisplasias/congênito , Osteocondrodisplasias/genética , Doenças da Imunodeficiência Primária , Ligação Proteica , RNA Longo não Codificante/genética , Transcrição Gênica/genética
14.
Environ Res ; 199: 111346, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34019898

RESUMO

The single adsorption of radioactive barium (Ba(II)), cobalt (Co(II)), and strontium (Sr(II)) ions using pristine (SCWB-P) and chemically activated spent coffee waste biochars with NaOH (SCWB-A) were thoroughly explored in order to provide deeper insights into the changes in their adsorption mechanisms through alkaline chemical activation. The greater removal efficiencies of SCWB-A (76.6-97.3%) than SCWB-P (45.6-75.2%) and the consistency between the adsorptive removal patterns (Ba(II) > Sr(II) > Co(II)) and oxygen bond dissociation enthalpies (BaO (562 kJ/mol) > SrO (426 kJ/mol) > CoO (397 kJ/mol)) of radioactive species supported the assumption that the adsorption removal of radioactive species with spent coffee waste biochars highly depended on the abundances of O-containing functional groups. The calculated R2 values of the pseudo-first-order (SCWB-P = 0.998-0.999; SCWB-A = 0.850-0.921) and pseudo-second-order kinetic models (SCWB-P = 0.988-0.998; SCWB-A = 0.935-0.966) are evident that the physisorption mainly controlled the adsorption of radioactive species toward SCWB-P and the chemisorption played a crucial role in their adsorptive removal with SCWB-A. From the calculated intra-particle diffusion, isotherm, thermodynamic parameters, it can be concluded that the intra-particle diffusion and monolayer adsorption primarily governed the adsorption of radioactive species using SCWB-P and SCWB-A, and their adsorption processes occurred spontaneously and endothermically. The dominant adsorption mechanism of spent coffee waste biochars was changed from physisorption (ΔH° of SCWB-P = 21.6-29.8 kJ/mol) to chemisorption (ΔH° of SCWB-A = 42.4-81.3 kJ/mol) through alkaline chemical activation. The distinctive M-OH peak in the O1s XPS spectra of SCWB-A directly corresponding to the decrease in the abundances of O-containing functional groups confirms again that the enrichment of O-containing functional groups markedly facilitated the adsorption removal of radioactive species by chemisorption occurred at the inner and outer surfaces of spent coffee waste biochars.


Assuntos
Estrôncio , Poluentes Químicos da Água , Adsorção , Bário , Carvão Vegetal , Cobalto , Café , Íons , Cinética , Termodinâmica , Poluentes Químicos da Água/análise
15.
Proc Natl Acad Sci U S A ; 115(16): 4282-4287, 2018 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-29610348

RESUMO

Cigarette smoking is the leading cause of preventable disease and death in the United States, with more persons dying from nicotine addiction than any other preventable cause of death. Even though smoking cessation incurs multiple health benefits, the abstinence rate remains low with current medications. Here we show that the AMP-activated protein kinase (AMPK) pathway in the hippocampus is activated following chronic nicotine use, an effect that is rapidly reversed by nicotine withdrawal. Increasing pAMPK levels and, consequently, downstream AMPK signaling pharmacologically attenuate anxiety-like behavior following nicotine withdrawal. We show that metformin, a known AMPK activator in the periphery, reduces withdrawal symptoms through a mechanism dependent on the presence of the AMPKα subunits within the hippocampus. This study provides evidence of a direct effect of AMPK modulation on nicotine withdrawal symptoms and suggests central AMPK activation as a therapeutic target for smoking cessation.


Assuntos
Proteínas Quinases Ativadas por AMP/efeitos dos fármacos , Transtornos de Ansiedade/tratamento farmacológico , Hipocampo/efeitos dos fármacos , Metformina/uso terapêutico , Proteínas do Tecido Nervoso/efeitos dos fármacos , Nicotina/efeitos adversos , Síndrome de Abstinência a Substâncias/tratamento farmacológico , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/fisiologia , Aminoimidazol Carboxamida/análogos & derivados , Aminoimidazol Carboxamida/farmacologia , Animais , Transtornos de Ansiedade/induzido quimicamente , Transtornos de Ansiedade/enzimologia , Avaliação Pré-Clínica de Medicamentos , Ativação Enzimática/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Hipocampo/enzimologia , Masculino , Metformina/farmacologia , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso/fisiologia , Ribonucleotídeos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Síndrome de Abstinência a Substâncias/enzimologia , Tabagismo/enzimologia , Tabagismo/psicologia
16.
Sensors (Basel) ; 21(9)2021 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-33922953

RESUMO

The deep random forest (DRF) has recently gained new attention in deep learning because it has a high performance similar to that of a deep neural network (DNN) and does not rely on a backpropagation. However, it connects a large number of decision trees to multiple layers, thereby making analysis difficult. This paper proposes a new method for simplifying a black-box model of a DRF using a proposed rule elimination. For this, we consider quantifying the feature contributions and frequency of the fully trained DRF in the form of a decision rule set. The feature contributions provide a basis for determining how features affect the decision process in a rule set. Model simplification is achieved by eliminating unnecessary rules by measuring the feature contributions. Consequently, the simplified and transparent DRF has fewer parameters and rules than before. The proposed method was successfully applied to various DRF models and benchmark sensor datasets while maintaining a robust performance despite the elimination of a large number of rules. A comparison with state-of-the-art compressed DNNs also showed the proposed model simplification's higher parameter compression and memory efficiency with a similar classification accuracy.

17.
FASEB J ; 33(12): 14137-14146, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31657647

RESUMO

Metformin has been shown to alter cell adhesion protein expression, which is thought to play a role in its observed antitumor properties. We found that metformin treatment down-regulated integrin ß1 concomitant with the loss of inositol polyphosphate multikinase (IPMK) in murine myocytes, adipocytes, and hepatocytes. To determine if IPMK was upstream of integrin ß1 expression, we examined IPMK-/- mouse embryonic fibroblast cells and found that integrins ß1 and ß3 gene expression was reduced by half, relative to wild-type cells, whereas focal adhesion kinase (FAK) activity and Rho/Rac/Cdc42 protein levels were increased, resulting in migration defects. Using nanonet force microscopy, we determined that cell:extracellular matrix adhesion and cell contractility forces were decreased, confirming the functional relevance of integrin and Rho protein dysregulation. Pharmacological studies showed that inhibition of both FAK1 and proline-rich tyrosine kinase 2 partially restored integrin ß1 expression, suggesting negative regulation of integrin ß1 by FAK. Together our data indicate that IPMK participates in the regulation of cell migration and provides a potential link between metformin and wound healing impairment.-Tu-Sekine, B., Padhi, A., Jin, S., Kalyan, S., Singh, K., Apperson, M., Kapania, R., Hur, S. C., Nain, A., Kim, S. F. Inositol polyphosphate multikinase is a metformin target that regulates cell migration.


Assuntos
Metformina/farmacologia , Fosfotransferases (Aceptor do Grupo Álcool)/antagonistas & inibidores , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Animais , Movimento Celular , Regulação para Baixo , Fibroblastos , Quinase 1 de Adesão Focal/genética , Quinase 1 de Adesão Focal/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Hipoglicemiantes/farmacologia , Integrina beta1/genética , Integrina beta1/metabolismo , Camundongos , Camundongos Knockout , Fosfotransferases (Aceptor do Grupo Álcool)/genética
18.
Langmuir ; 36(12): 3046-3056, 2020 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-32151131

RESUMO

The tunable surface-wetting properties of photosensitive random copolymer mats were used to spatially control the orientations of thin-film block copolymer (BCP) structures. A photosensitive mat was produced via thermal treatment on spin-coated random copolymers of poly(styrene-ran-2-nitrobenzyl methacrylate-ran-glycidyl methacrylate), synthesized via reversible-deactivation radical polymerization. The degree of UV-induced deprotection of the nitrobenzyl esters in the mat was precisely controlled through the amount of UV-irradiation energy imparted to the mat. The resulting polarity switching of the constituents collectively altered the interfacial wetting properties of the mat, and the tunability allowed lamellar or cylinder-forming poly(styrene-b-methyl methacrylate) BCP thin films, applied over the mat, to change the domain orientation from perpendicular to parallel at proper UV exposures. UV irradiation passing through a photomask was capable of generating defined regions of BCP domains with targeted orientations.

19.
Sensors (Basel) ; 20(18)2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32916968

RESUMO

As the demand for human-friendly computing increases, research on pupil tracking to facilitate human-machine interactions (HCIs) is being actively conducted. Several successful pupil tracking approaches have been developed using images and a deep neural network (DNN). However, common DNN-based methods not only require tremendous computing power and energy consumption for learning and prediction; they also have a demerit in that an interpretation is impossible because a black-box model with an unknown prediction process is applied. In this study, we propose a lightweight pupil tracking algorithm for on-device machine learning (ML) using a fast and accurate cascade deep regression forest (RF) instead of a DNN. Pupil estimation is applied in a coarse-to-fine manner in a layer-by-layer RF structure, and each RF is simplified using the proposed rule distillation algorithm for removing unimportant rules constituting the RF. The goal of the proposed algorithm is to produce a more transparent and adoptable model for application to on-device ML systems, while maintaining a precise pupil tracking performance. Our proposed method experimentally achieves an outstanding speed, a reduction in the number of parameters, and a better pupil tracking performance compared to several other state-of-the-art methods using only a CPU.


Assuntos
Tecnologia de Rastreamento Ocular , Aprendizado de Máquina , Redes Neurais de Computação , Pupila , Algoritmos , Humanos
20.
Small ; 15(16): e1805006, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30829003

RESUMO

Biocompatibility and high responsiveness to magnetic fields are fundamental requisites to translate magnetic small-scale robots into clinical applications. The magnetic element iron exhibits the highest saturation magnetization and magnetic susceptibility while exhibiting excellent biocompatibility characteristics. Here, a process to reliably fabricate iron microrobots by means of template-assisted electrodeposition in 3D-printed micromolds is presented. The 3D molds are fabricated using a modified two-photon absorption configuration, which overcomes previous limitations such as the use of transparent substrates, low writing speeds, and limited depth of field. By optimizing the geometrical parameters of the 3D molds, metallic structures with complex features can be fabricated. Fe microrollers and microswimmers are realized that demonstrate motion at ≈20 body lengths per second, perform 3D motion in viscous environments, and overcome higher flow velocities than those of "conventional 3D printed helical microswimmers." The cytotoxicity of these microrobots is assessed by culturing them with human colorectal cancer (HCT116) cells for four days, demonstrating their good biocompatibility characteristics. Finally, preliminary results regarding the degradation of iron structures in simulated gastric acid liquid are provided.


Assuntos
Ferro/química , Campos Magnéticos , Microtecnologia/métodos , Impressão Tridimensional/instrumentação , Robótica/instrumentação , Materiais Biocompatíveis , Eletroquímica , Galvanoplastia , Células HCT116 , Humanos , Hidrogênio/química , Imãs , Microfluídica , Robótica/métodos , Propriedades de Superfície
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA