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1.
Nanoscale ; 2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-33481982

RESUMO

Topological Weyl semimetals have attracted considerable interest because they manifest underlying physics and device potential in spintronics. Large anomalous Hall effect (AHE) in non-collinear antiferromagnets (AFMs) represents a striking Weyl phase, which is associated with Bloch-band topological features. In this work, we report robust AHE and Lifshitz transition in high-quality Weyl semimetal Mn3Ge thin film, comprising stacked Kagome lattice and chiral antiferromagnetism. We successfully achieved giant AHE in our Mn3Ge film, with a strong Berry curvature enhanced by the Weyl phase. The enormous coercive field HC in our AHE curve at 5 K reached an unprecedented 5.3 T among hexagonal Mn3X systems. Our results provide direct experimental evidence of an electronic topological transition in the chiral AFMs. The temperature was demonstrated to play an efficient role in tuning the carrier concentration, which could be quantitatively determined by the two-band model. The electronic band structure crosses the Fermi energy level and leads to the reversal of carrier type around 50 K. The results not only offer new functionality for effectively modulating the Fermi level location in topological Weyl semimetals but also present a promising route of manipulating the carrier concentration in antiferromagnetic spintronic devices.

2.
Ecotoxicology ; 2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33432458

RESUMO

Long-term frequent tillage would cause black soil degradation and serious soil erosion as soil microbial communities and soil structure are extremely sensitive to tillage process. However, there is no unified conclusion on the relationship between the distribution of soil water-stable aggregates (WSAs), and microbial community construction and diversity under long-term tillage in black soil during different seasons. In this study, we used wet-sieving method to evaluate the composition and stability of soil WSAs and employed Illumina MiSeq high-throughput sequencing technology to study the diversity, taxonomic composition and co-occurrence network properties of microbial community, comparing outcomes between uncultivated soil and long-term cultivated soil for 60 years in Keshan farm of Heilongjiang Province. The results showed that after long-term tillage, the proportion of larger than 1 mm WSAs reduced by 34.17-51.37%, and the stability of WSAs, soil pH, organic matter (OM), total nitrogen (TN) contents decreased significantly in all seasons (P < 0.05), while soil available phosphorus (AP) and available potassium (AK) contents increased remarkably (P < 0.05). The diversity of bacteria increased, while that of fungi decreased. Soil fungal communities were more susceptible to long-term tillage than bacterial and archaeal communities. Actinobacteria mainly exist in large WSAs (˃1 mm), and when their relative abundance is high, it is beneficial to improve the water-stability of black soil; while Proteobacteria and Gemmatimonadetes may exist in small WSAs (˂1 mm), whose high relative abundance will weaken the water-stability of black soil. The experimental results provide a scientific theoretical basis for sustainable utilization of black soil.

3.
Int J Med Sci ; 18(4): 902-910, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33456347

RESUMO

The pathogenesis of hallux valgus is not clearly understood. However, genetics research about hallux valgus is rare. Therefore, the present study aimed to explore the pathogeny of hallux valgus from the perspective of genetics. Human samples were collected from normal bone tissue and hallux valgus region bone tissue. The bone samples were studied using real time-PCR, western blot and immunohistochemical. Lentivirus-mediated miR-182 transfected osteoblasts and tested the expression of FGF9 mRNA with real time-PCR. To test alkaline phosphatase activity, number of calcium nodules and proliferation of osteoblast with enzymatic activity analysis, calcium nodules stained and MTT assay. We found that (1) FGF9 expressed in hallux valgus region bone tissue was significantly higher than normal bone tissue. (2) miR-182 expression levels in hallux valgus region bone tissue were notably lower than those of normal bone tissue. (3) miR-182 could negatively regulate the expression of FGF9 in osteoblasts. (4) FGF9 may enhance osteoblasts proliferation. We have demonstrated that miR-182 promotes the formation of bone by targeting FGF9, implicating an essential role of miR-182 in the etiology of hallux valgus. Moreover, miR-182 might potentially be a therapeutic target for hallux valgus treatment.

4.
Huan Jing Ke Xue ; 41(11): 4958-4969, 2020 Nov 08.
Artigo em Chinês | MEDLINE | ID: mdl-33124239

RESUMO

It is very important to understand water ecology and the carbon cycle process by studying the composition, source, spectral characteristics, and influence factors of chromophoric dissolved organic matter (CDOM). The optical characteristics, composition, and source of CDOM in 71 water samples were collected from the lakes and four rivers of the Taibaishan Nature Reserve in the summer of 2019. The rivers included the Bawang, Heihe, Shitou, and Xushui Rivers. They were analyzed by UV-Vis spectral and three-dimensional fluorescence spectroscopy, combined with a parallel factor analysis model and redundant analysis. The results showed that CDOM in the water of the Taibaishan Nature Reserve contained two types of four fluorescent components, in which the humus-like components C1 and C2 were the main components of CDOM. The relative contribution of C1 and C2 to the rivers was 82%-96%, which was significantly larger than the lakes. All fluorescence indexes (FI) were larger than 1.8, the index of recent autochthonous contribution (BIX), and the index of freshness (ß:α) were all approximately 0.6. The humification indexes (HIX) of the rivers were significantly larger than those of the lakes (P<0.01). The DOM in the rivers was mainly from the forest soil of the Nature Reserve, and the water quality of the lakes was affected by tourists to some extent. The results of the redundant analysis show that the CDOM spectral characteristic parameters were significantly influenced by EC for the lakes (P<0.05) and by EC, DTN, and DOC for the rivers (P<0.01).


Assuntos
Monitoramento Ambiental , Água , China , Lagos , Rios , Espectrometria de Fluorescência , Qualidade da Água
5.
Eur J Haematol ; 105(3): 326-334, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32421883

RESUMO

BACKGROUND: In multiple myeloma (MM), impact of specific chromosomal translocations involving IgH (14q21 locus, including t(4;14), t(11;14), and t(14;16)) has been explored extensively. However, over 15% MM patients harboring IgH translocation with undefined partners have long been ignored. METHODS: A prospective non-randomized cohort study with a total of 715 newly-diagnosed MM cases was conducted, 13.6% of whom were t(14;undefined) positive. The whole cohort was divided into four groups: no IgH split (47.7%); t(14;undefined) (13.6%); t(11;14) (17.6%); and t(4;14) or t(14;16) group (21.1%). RESULTS: Median OS for the four groups was 84.2, not reached (NR), 58.7, and 44.2 months, respectively, with P values for t(14;undefined) vs no IgH split, t(11;14), and t(4;14)/t(14;16) groups of 0.197, 0.022, and 0.001, respectively. In bortezomib-based group, the survival advantage gained by t(14;undefined) group was much more significant compared to t(11;14) and t(4;14)/t(14;16) groups. Importantly, t(14;undefined) turned out to be an independent predictive factor for longer OS of MM patients in multivariate analysis, especially in the context of bortezomib treatment. Similar results were also observed in the PUMCH external validation cohort. CONCLUSION: Collectively, our data confirmed and externally validated the favorable prognosis of the t(14;undefined) groups, especially in the era of novel agents.

6.
Cell Mol Biol Lett ; 25: 26, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32308692

RESUMO

Background: Oxidative stress results in cell apoptosis/death and plays a detrimental role in disease development and progression. Stressors alter the miRNA expression profile and miRNAs play a role in the cell response to stress. We previously showed that miR-711 is significantly over-expressed in extended cold ischemia reperfusion injured hearts in heart transplant. In this study, we aimed to investigate the role of miR-711 in cardiac cell damage in response to oxidative stress and how miR-711 is regulated. Methods: Rat cardiac cell line H9c2 cells were cultured and exposed to oxidative conditions (Antimycin A (AA), H2O2, CoCl2, or cold hypoxia/reoxygenation (H/R)) in vitro. H9c2 cells were transfected with miR-711 mimics, miR-711 inhibitors, or small interference RNA, using transfection reagents. The expression of miR-711 was measured by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Cell apoptosis/death was detected by flow cytometry and an IncuCyte system. Mitochondrial damage was detected by measuring the mitochondria membrane potential by flow cytometry. Gene expression was detected by qRT-PCR at the mRNA level and Western blotting and immunocytochemistry staining at the protein level. Results: We found that miR-711 was significantly up-regulated in cells treated with H2O2, AA, CoCl2, and cold H/R. Over-expression of miR-711 increased cell apoptosis/death induced by AA and H/R whereas cell death was reduced by miR-711 inhibitors. MiR-711 induced cell death through negative regulation of angiopoietin 1 (Ang-1), fibroblast growth factor 14 (FGF14) and calcium voltage-gated channel subunit alpha1C (Cacna1c) genes. Both knockdown of hypoxia inducible factor 1α (HIF-1α) and inactivation of the nuclear factor kappa-light-chain-enhancer of activated B cells (NFКB) pathway inhibited over-expression of miR-711. Conclusion: Oxidative stress increases the expression of miR-711. Over-expression of miR-711 induces cell apoptosis/death. HIF-1α and NFКB regulate miR-711 in H9c2 cells during oxidative stress. miR-711 is a new target for preventing oxidative stress.

7.
Mol Ther Nucleic Acids ; 19: 458-467, 2020 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-31902745

RESUMO

Ischemia-reperfusion (I/R) injury occurs during cardiac surgery and is the major factor leading to heart dysfunction and heart failure. Our previous study showed that gene and microRNA expression profiles are altered in heart grafts with extended I/R injury. In this study, we, for the first time, demonstrated that I/R injury upregulates the expression of Polo-like kinase 2 (Plk2) but decreases miR-128 expression in heart cells both in vitro and in vivo. Silencing Plk2 using small interfering RNA (siRNA) protects cells from Antimycin A-induced cell apoptosis/death. Silencing Plk2 also decreases phosphorylated p65 expression but increases Angiopoietin 1 expression. In addition, Plk2 is negatively regulated by miR-128. miR-128 exerts a protective effect on cell apoptosis similar to Plk2 siRNA in response to I/R stress. Methylation inhibitor 5-azacytidine (5-AZ) increases the expression of miR-128 and subsequently reduces Plk2 expression and cell apoptosis. In conclusion, this study demonstrated that Plk2 regulated by miR-128 induces cell apoptosis/death in response to I/R stress through activation of the nuclear factor κB (NF-κB) signal pathway. miR-128 and Plk2 are new targets for preventing cardiac I/R injury or oxidative stress-mediated injury.

8.
Mater Sci Eng C Mater Biol Appl ; 108: 110198, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31923997

RESUMO

With high level of morbidity and mortality, tumor is one of the deadliest diseases worldwide. Aiming to tackle tumor, researchers have developed a lot of strategies. Among these strategies, the minimally invasive therapy (MIT) is very promising, for its capability of targeting tumor cells and resulting in a small incision or no incisions. In this review, we will first illustrate some mechanisms and characteristics of tumor metastasis from the primary tumor to the secondary tumor foci. Then, we will briefly introduce the history, characteristics, and advantages of some of the MITs. Finally, emphasis will be, respectively, focused on an overview of the state-of-the-art of the HIFU-, PDT-, PTT-and SDT-based anti-tumor strategies on each stage of tumor metastasis.


Assuntos
Sistemas de Liberação de Medicamentos , Neoplasias/tratamento farmacológico , Humanos , Neoplasias/metabolismo , Neoplasias/patologia
9.
IEEE Trans Neural Netw Learn Syst ; 31(10): 4094-4103, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31831447

RESUMO

This article presents a novel perspective to improve the ride quality of high-speed trains (HSTs), namely, by virtue of the periodicity of lateral dynamics to suppress the lateral vibration of HST. To resolve the contradiction between the complex HST model and the effective controller design, a simplified three-degrees-of-freedom (3-DOF) quarter-vehicle model is first employed for controller design, while a 17-DOF full-vehicle model is built for efficiency verification, where periodic and random track irregularities are considered, respectively. An active repetitive learning control (RLC) method is proposed to achieve the periodic tracking control, where the learning convergence is proved rigorously in a Lyapunov way. The configuration of RLC-based lateral suspensions is economical in the sense that only four actuators and six sensors are needed. It is verified by simulation that, compared with the dynamic matrix controller, the proposed RLC controller has greatly reduced the lateral vibration of a vehicle body, especially the lateral acceleration in the frequency range of (0, 3] Hz to which human body is strongly sensitive.

11.
Medicine (Baltimore) ; 98(24): e15905, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31192925

RESUMO

RATIONAL: The occurrence of Ewing's sarcoma in the vertebral body of elderly women is extremely rare, and the case of Ewing's sarcoma in the spine with secondary surgical repair after wrong diagnosis and treatment has not been reported. We report a case involving primary Ewing's sarcoma of the vertebral body in an elderly female. Owing to its rarity and controversial issues, we report a case report to discuss its clinical features, treatments, radiological, and histological characteristics. PATIENT CONCERNS: The elderly female patient came to see us with the manifestation of total paralysis of both lower limbs. The patient with a vertebral compression fracture as the primary manifestation was misdiagnosed in another hospital. The patient underwent inappropriate surgical treatment and was transferred to our hospital for diagnosis and second-stage surgery. DIAGNOSES: The postoperative pathological examination and immunohistochemical examination in our hospital confirmed: Ewing's sarcoma; Surgical history at other hospitals suggests: after Bone cement injection. INTERVENTIONS: The patient underwent a T6 and T8 laminectomy and T5/6-T9 pedicle screw fixation. OUTCOMES: Reexamination 1 month after the surgery showed that the tumor had been partially resected, the spinal cord compression was relieved, the tumor did not grow further, and the patient's lower limb physical ability, tactile sense, algesia and temperature sense recovered slightly. LESSONS: For patients with ewing's tumor in the spinal canal with symptoms of spinal cord compression, even if the patients with poor results after a unadvisable operation, it is still necessary to be actively in spinal cord compression by surgery. The differential diagnosis of Ewing's sarcoma and compression fractures is very important. For patients with vertebral tumors, special attention should be taken during vertebroplasty for bone cement leakage caused by excessive bone cement injection and increased local pressure. And some experience with imaging and laboratory findings.


Assuntos
Laminectomia/instrumentação , Sarcoma de Ewing/cirurgia , Neoplasias da Coluna Vertebral/cirurgia , Erros de Diagnóstico , Feminino , Fraturas por Compressão/cirurgia , Humanos , Pessoa de Meia-Idade , Parafusos Pediculares , Recuperação de Função Fisiológica , Compressão da Medula Espinal/cirurgia , Resultado do Tratamento
12.
Exp Ther Med ; 16(6): 4373-4378, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30542386

RESUMO

The aim of the study was to investigate the expression of miR-155 in plasma and peripheral blood mononuclear cells (PBMCs), the effects of miR-155 on the apoptosis rate of PBMCs and the extent of coronary stenosis in coronary artery disease patients. Seventy chest pain patients were divided into three groups by symptoms, signs, auxiliary examination and coronary arteriography: 21 cases in the acute myocardial infarction group (AMI), 23 cases in the Angor pectoris group (AP) and 26 cases in the control group (CT). The peripheral blood mononuclear cells of the patients in the three groups were separated for cell culture. Annexin V/propidium iodide (PI) was performed to analyze cell apoptosis. RT-qPCR was used to evaluate the expression level of miR-155 in plasma and PBMCs. There were significant differences on the expression of miR-155 in plasma and PBMCs, the apoptosis rate of PBMCs, Gensini score and the extent of coronary stenosis among the three groups (P<0.05). The expression of miR-155 in plasma and PBMCs in AMI and AP group were lower than CT group while the AMI group was lower than the AP group (P<0.05). The apoptotic rate of PBMCs, Gensini score and the extent of coronary stenosis of the AMI and AP groups were higher than CT group while the AMI group was higher than the AP group (P<0.05). The expression of miR-155 in plasma was positively correlated with PBMCs, but negatively correlated with the apoptosis rate of PBMCs, Gensini score and the extent of coronary stenosis. The apoptosis rate of PBMCs in patients with coronary heart disease was positively correlated with the degree of coronary artery stenosis and Gensini score. In conclusion, in the patients with coronary heart disease the apoptosis rate of PBMCs was increased and the expression of miR-155 in plasma and PBMCs cells was decreased, which were correlated with the severity of coronary heart disease.

13.
Front Immunol ; 9: 2407, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30425709

RESUMO

Recombinant human growth differentiation factor 15 (rhGDF15) affects dendritic cell (DC) maturation. However, whether GDF15 is expressed in DCs and its roles and signaling in DCs remain largely unknown. It is unclear whether GDF15-DCs can induce immune tolerance in heart transplantation (HT). This study aims to understand the impact of endogenous GDF15 on DC's development, function, underlying molecular mechanism including circular RNA (circRNA). This study will also explore GDF15-DC-mediated immune modulation in HT. Bone marrow (BM) derived DCs were cultured and treated to up- or down regulate GDF15 expression. Phenotype and function of DCs were detected. Expression of genes and circRNAs was determined by qRT-PCR. The signaling pathways activated by GDF15 were examined. The impact of GDF15 treated DCs on preventing allograft immune rejection was assessed in a MHC full mismatch mouse HT model. Our results showed that GDF15 was expressed in DCs. Knockout of GDF15 promoted DC maturation, enhanced immune responsive functions, up-regulated malat-1 circular RNA (circ_Malat 1), and activated the nuclear factor kappa B (NFκB) pathway. Overexpression of GDF15 in DCs increased immunosuppressive/inhibitory molecules, enhanced DCs to induce T cell exhaustion, and promoted Treg generation through IDO signaling. GDF15 utilized transforming growth factor (TGF) ß receptors I and II, not GFAL. Administration of GDF15 treated DCs prevented allograft rejection and induced immune tolerance in transplantation. In conclusion, GDF15 induces tolerogenic DCs (Tol-DCs) through inhibition of circ_Malat-1 and the NFκB signaling pathway and up-regulation of IDO. GDF15-DCs can prevent alloimmune rejection in HT.


Assuntos
Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Rejeição de Enxerto/genética , Rejeição de Enxerto/imunologia , Fator 15 de Diferenciação de Crescimento/metabolismo , Tolerância Imunológica , NF-kappa B/metabolismo , RNA Longo não Codificante/genética , Animais , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Células Dendríticas/citologia , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Fator 15 de Diferenciação de Crescimento/farmacologia , Transplante de Coração/efeitos adversos , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Transplante Homólogo
14.
Sensors (Basel) ; 18(1)2017 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-29278376

RESUMO

Due to the non-contact nature, using Doppler radar sensors to detect vital signs such as heart and respiration rates of a human subject is getting more and more attention. However, the related detection-method research meets lots of challenges due to electromagnetic interferences, clutter and random motion interferences. In this paper, a novel third-order cyclic cummulant (TOCC) detection method, which is insensitive to Gaussian interference and non-cyclic signals, is proposed to investigate the heart and respiration rate based on continuous wave Doppler radars. The k-th order cyclostationary properties of the radar signal with hidden periodicities and random motions are analyzed. The third-order cyclostationary detection theory of the heart and respiration rate is studied. Experimental results show that the third-order cyclostationary approach has better estimation accuracy for detecting the vital signs from the received radar signal under low SNR, strong clutter noise and random motion interferences.

15.
Oncotarget ; 8(22): 36531-36544, 2017 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-28388574

RESUMO

Ischemia reperfusion (I/R) injury which inevitably occurs during heart transplantation is the major factor leading to organ failure and graft rejection. In order to develop new therapies to prevent I/R injury, we used both a murine heart transplantation model with 24 hour cold I/R and an in vitro cell culture system to determine whether growth differentiation factor 15 (GDF15) is a protective factor in preventing I/R injury in heart transplantation and to further investigate underlying mechanisms of I/R injury. We found that cold I/R caused severe damage to the endocardium, epicardium and myocardium of heart grafts from wild type C57BL/6 mice, whereas grafts from GDF15 transgenic (TG) mice showed less damage as demonstrated by decreased cell apoptosis/death, decreased neutrophils infiltration and the preservation of the normal structure of the heart. Over-expression of GDF15 reduced expression of phosphorylated RelA p65, pre-inflammatory and pro-apoptotic genes while it enhanced Foxo3a phosphorylation in vitro and in vivo. Over-expression of GDF15 inhibited cell apoptosis/death and reduced neutrophil infiltration. In conclusion, this study, for the first time, demonstrates that GDF15 is a promising target for preventing cold I/R injury in heart transplantation. This study also shows that the resultant protective effects are mediated by the Foxo3 and NFκB signaling pathways.


Assuntos
Isquemia Fria/efeitos adversos , Proteína Forkhead Box O3/metabolismo , Expressão Gênica , Fator 15 de Diferenciação de Crescimento/genética , Transplante de Coração , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/metabolismo , Animais , Apoptose/genética , Citocinas/genética , Citocinas/metabolismo , Humanos , Mediadores da Inflamação/metabolismo , Masculino , Camundongos , Miócitos Cardíacos/metabolismo , Peroxidase/metabolismo , Fosforilação , Ratos , Traumatismo por Reperfusão/prevenção & controle , Transdução de Sinais
16.
Sci Rep ; 7(1): 1037, 2017 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-28432312

RESUMO

Septic acute kidney injury (AKI) and myocardial dysfunction are leading causes of mortality with no accepted method of therapy. In this study we demonstrate the role of growth differentiating factor 15 (GDF15) in septic AKI and myocardial dysfunction using a murine lipopolysaccharide (LPS)-induced sepsis model and an in vitro cell culture system. Data show that GDF15 deficiency augments inflammatory response and exacerbates renal and cardiac injury induced by LPS, while over-expression of GDF15 protects the kidney and heart from LPS-induced organ dysfunction. Therefore, this study highlights the therapeutic potential of GDF15 in the treatment of endotoxin-induced sepsis.


Assuntos
Lesão Renal Aguda/induzido quimicamente , Cardiomiopatias/induzido quimicamente , Fator 15 de Diferenciação de Crescimento/deficiência , Lipopolissacarídeos/efeitos adversos , Lesão Renal Aguda/genética , Lesão Renal Aguda/imunologia , Lesão Renal Aguda/fisiopatologia , Animais , Cardiomiopatias/genética , Cardiomiopatias/imunologia , Cardiomiopatias/fisiopatologia , Células Cultivadas , Modelos Animais de Doenças , Técnicas de Inativação de Genes , Humanos , Masculino , Camundongos , Sepse
17.
J Colloid Interface Sci ; 478: 413-20, 2016 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-27344354

RESUMO

An amperometric determination of nitrite in different water samples was evaluated using palladium nanoparticles (PdNPs) decorated functionalized multiwalled carbon nanotubes (f-MWCNT) modified glassy carbon electrode. The f-MWCNT/PdNPs composite modified electrode was prepared by electrodeposition of PdNPs on the surface of f-MWCNT modified electrode. The parameters such as effect of number of cycles of PdNPs deposition, drop coated amount of f-MWCNT and effect of pH were optimized and discussed in detail. As-prepared f-MWCNT/PdNPs composite modified electrode exhibits excellent electrocatalytic activity towards the oxidation of nitrite compared to MWCNT, f-MWCNT and PdNPs modified electrodes. Amperometric i-t method was used to determine nitrite and the response of the nitrite on modified electrode was linear over the concentration from 0.05 to 2887.6µM. The response time of the sensor was estimated as 3s with the detection limit of 22nM. The fabricated f-MWCNT/PdNPs composite modified electrode shows its satisfactory practical ability in nitrite containing different water samples, which authenticate its potential ability for determination of nitrite.

18.
J Colloid Interface Sci ; 470: 117-122, 2016 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-26939075

RESUMO

In this paper, we report a highly sensitive amperometric H2O2 sensor based on silver nanowires (AgNWs) modified screen printed carbon electrode. The AgNWs were synthesized using polyol method. The synthesized AgNWs were characterized by scanning electron microscopy, UV-vis spectroscopy and X-ray diffraction techniques. The average diameter and length of the synthesized AgNWs were found as 86±5 and 385nm, respectively. Under optimum conditions, the AgNWs modified electrode shows a stable amperometric response for H2O2 and was linear over the concentrations ranging from 0.3 to 704.8µM. The non-enzymatic sensor showed a high sensitivity of 662.6µAmM(-1)cm(-2) with a detection limit of 29nM. The response time of the sensor was found as 2s. Furthermore, the AgNWs modified electrode exhibited a good recovery of H2O2 (94.3%) in the human blood serum samples.


Assuntos
Peróxido de Hidrogênio/sangue , Nanofios/química , Prata/química , Eletrodos , Humanos , Tamanho da Partícula , Propriedades de Superfície
19.
Biochemistry ; 54(45): 6806-14, 2015 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-26507929

RESUMO

Cardiovascular disease is the leading cause of morbidity and mortality in patients with type 2 diabetes mellitus (T2DM). Pioglitazone, the widely used thiazolidinedione, is shown to be efficient in the prevention of cardiovascular complications of T2DM. In this study, we report that pioglitazone inhibits CXCR7 expression and thus blocks chemotaxis in differentiated macrophage without perturbing cell viability or macrophage differentiation. In addition, pioglitazone-mediated CXCR7 suppression and chemotaxis inhibition occur via activating peroxisome proliferator-activated receptor γ (PPARγ) but not PPARα in differentiated macrophage. More importantly, pioglitazone therapy-induced PPARγ activation suppresses CXCR7 expression in human carotid atherosclerotic lesions. Collectively, our data demonstrate that pioglitazone suppresses CXCR7 expression to inhibit human macrophage chemotaxis through PPARγ.


Assuntos
Quimiotaxia/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , PPAR gama/agonistas , Receptores CXCR/antagonistas & inibidores , Tiazolidinedionas/farmacologia , Benzamidas/farmacologia , Doenças das Artérias Carótidas/complicações , Doenças das Artérias Carótidas/tratamento farmacológico , Doenças das Artérias Carótidas/metabolismo , Doenças das Artérias Carótidas/cirurgia , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Terapia Combinada , Depressão Química , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Regulação para Baixo , Endarterectomia das Carótidas , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , PPAR alfa/efeitos dos fármacos , PPAR alfa/genética , PPAR gama/antagonistas & inibidores , PPAR gama/genética , PPAR gama/fisiologia , Pioglitazona , Piridinas/farmacologia , Interferência de RNA , RNA Interferente Pequeno/farmacologia , Receptores CXCR/biossíntese , Receptores CXCR/genética , Rosiglitazona
20.
Eur J Pharmacol ; 748: 30-6, 2015 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-25523481

RESUMO

Cerebrovascular disease (CVD) ranks as the top three health risks, specially cerebral ischemia characterized with the damage of blood-brain barrier (BBB). The angiotensin Ang-(1-7) was proven to have a protective effect on cerebrovascular diseases. However, its role on blood-brain barrier and the underlying molecular mechanism remains unclear. In this study, Ang-(1-7) significantly relieved damage of ischemia reperfusion injury on blood-brain barrier in cerebral ischemia reperfusion injury (IRI) rats. Furthermore, its treatment attenuated BBB permeability and brain edema. Similarly, Ang-(1-7) also decreased the barrier permeability of brain endothelial cell line RBE4. Further analysis showed that Ang-(1-7) could effectively restore tight junction protein (claudin-5 and zonula occludens ZO-1) expression levels both in IRI-rats and hypoxia-induced RBE4 cells. Furthermore, Ang-(1-7) stimulation down-regulated hypoxia-induced matrix metalloproteinase-9 (MMP-9) levels, whose silencing with (matrix metalloproteinase-9 hemopexin domain) MMP9-PEX inhibitor significantly increased the expression of claudin-5 and ZO-1. Further mechanism analysis demonstrated that Ang-(1-7) might junction protein levels by tissue inhibitor of metalloproteinase 1 (TIMP1)-MMP9 pathway, because Ang-(1-7) enhanced TIMP1 expression, whose silencing obviously attenuated the inhibitor effect of Ang-(1-7) on MMP-9 levels and decreased Ang-(1-7)-triggered increase in claudin-5 and ZO-1. Together, this study demonstrated a protective role of Ang-(1-7) in IRI-induced blood-brain barrier damage by TIMP1-MMP9-regulated tight junction protein expression. Accordingly, Ang-(1-7) may become a promising therapeutic agent against IRI and its complications.


Assuntos
Angiotensina I/farmacologia , Barreira Hematoencefálica/efeitos dos fármacos , Metaloproteinase 9 da Matriz/metabolismo , Inibidores de Metaloproteinases de Matriz/farmacologia , Fragmentos de Peptídeos/farmacologia , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Angiotensina I/uso terapêutico , Animais , Barreira Hematoencefálica/metabolismo , Isquemia Encefálica/complicações , Linhagem Celular , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Inibidores de Metaloproteinases de Matriz/uso terapêutico , Fragmentos de Peptídeos/uso terapêutico , Ratos , Traumatismo por Reperfusão/complicações , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Proteínas de Junções Íntimas/metabolismo , Inibidor Tecidual de Metaloproteinase-1/genética
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