Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.394
Filtrar
1.
Nanotechnology ; 31(3): 035603, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31557747

RESUMO

A key challenge in developing an ethanol oxidation reaction is nontoxic fabrication of highly active stable and low-cost catalysts. Here we design a green synthetic strategy of AgPd bimetallic nanosphere by a dual-template cascade method. The Pd nanoshell is firstly prepared using Vapreotide acetate as a primary template, and then the Ag nanoshell acts as a secondary template for the distribution of AgPd alloy nanoparticles. The AgPd nanoparticles have core-shell structures and various sizes, and their shell thicknesses are tuned by controlling the amount of PdCl2. The six different samples are prepared, named AgPd-1, AgPd-2, AgPd-3, AgPd-4, AgPd-5, and AgPd-6, respectively. The mass current density of AgPd-5, is higher 3.87 times that of commercial Pd/C, and exhibits the best ethanol oxidation reaction activity and long-term stability. The main reasons are that the AgPd-5 possessed excellent specific surface area due to their rough structure, and Ag can remove more CO-like species. This is the first time a Vapreotide acetate/Ag-template method has been used to synthesize a AgPd core-shell structure, which would have broad application prospects for direct ethanol fuel cells.

2.
J Nanosci Nanotechnol ; 20(2): 1238-1244, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383124

RESUMO

A series of ordered mesoporous Fe-MC-x nanocomposites were facilely synthesized via an evaporation induced self-assembly strategy. The Fe nanoparticles (NPs) were highly dispersed and embedded in mesoporous carbon channels, and their particle sizes (mean size = 8, 12 and 16 nm) were well tuned with the aid of acetylacetone chelating agent. Catalytic ammonia decomposition to COx-free hydrogen was used to evaluate their catalytic performances. It was found that the prepared Fe-MC-x nanocomposites showed an obvious size-dependent activity. Owing to confinement and size effect, the Fe-MC-8 nanocomposites with the smallest Fe NPs showed the highest ammonia decomposition activity, giving a nearly 72% NH3 conversion and 16.24 mol g-1Fe h-1 at 600 °C under a GHSV = 6000 h-1.

3.
J Cell Physiol ; 235(1): 281-293, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31215024

RESUMO

The inflammatory microenvironment in the joints is one of the critical issues during osteoarthritis (OA) and also the main factor that may aggravate symptoms. Under inflammatory microenvironment, M1 macrophages are activated and produce large numbers of proinflammatory mediators, leading to the production of degradative enzymes, the disturbance of chondrocyte apoptosis and cartilage catabolic processes, and finally the deterioration of OA. In the present study, we reveal that the overexpression of osteopontin (OPN), a cytokine, and a matrix protein involved in arthritis and chondrocyte apoptosis in OA, could exacerbate the inflammatory microenvironment in OA via promoting the production of proinflammation cytokines and the levels of degradative enzymes in M1 macrophages, therefore, enhancing the cytotoxicity of M1 macrophage on chondrocytes. XIST expression significantly increases in OA tissue specimens. XIST serves as a competing endogenous RNA for miR-376c-5p to compete with OPN for miR-376c-5p binding, thus counteracting miR-376c-5p-mediated OPN suppression. XIST knockdown could improve the inflammatory microenvironment in OA via acting on M1 macrophages, subsequently affecting the apoptosis of cocultured chondrocytes. miR-376c-5p inhibition exerts an opposing effect on M1 macrophages and cocultured chondrocytes, as well as significantly reverses the effect of XIST knockdown. As a further confirmation, XIST and OPN mRNA expression significantly increased in OA tissues and was positively correlated in tissue samples. In summary, we provide a novel mechanism of macrophages and the inflammatory microenvironment affecting chondrocyte apoptosis. XIST and OPN might be potential targets for OA treatment, which needs further in vivo experimental confirmation.

4.
Methods Mol Biol ; 2050: 21-27, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31468476

RESUMO

Micro/nanochannel electroporation can deliver gene/drug into single cell with precise dosage control and much higher cell viability compared to traditional bulk electroporation. However, single cell micro/nanochannel electroporation has the problems of low efficiency and complicated operation. By integrating microfluidic with micro/nanochannel electroporation, a large number of cells can be processed within a short time. In this chapter, we provide a detailed protocol of fabrication microfluidic nanochannel electroporation devices. The fabrication of this microfluidic nanochannel electroporation device integrates soft lithography, DNA combing and imprinting, and micromilling. This device is appropriate for gene/drug delivery to a batch of cells. It has the advantages of both the single cell nanochannel electroporation and microfluidic based cell manipulation. The procedures of device fabrication, holder fabrication, cell trapping, and electroporation are included in this protocol.

5.
J Nanosci Nanotechnol ; 20(3): 1878-1883, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31492356

RESUMO

It is demonstrated that Mg, Cr, Mn and B can be doped close to GaAs surface by plasma doping without external bias at room temperature (RT). The process only takes a few minutes, and impurity densities in the range of 1018-1021/cm3 can be achieved with doping depths about twenty nanometers. The experiment results are analyzed and the physical mechanism is tentatively explained as follows: during the doping process, impurity ion implantation under plasma sheath voltage takes place, simultaneously, plasma stimulates RT diffusion of impurity atom, which plays the main role in the doping process. The enhanced RT diffusion coefficients of Mg, Cr, Mn and B in GaAs are all in the order of magnitude of 10-15 cm2sec-1. This is reported for the first time among all kinds of plasma assisted doping methods.

6.
J Hazard Mater ; 382: 121014, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31445413

RESUMO

A single particle aerosol mass spectrometry (SPAMS) was deployed to investigate the mixing state and chemical processing of Pb-rich particles in suburban Beijing. Based on a large dataset of mass spectra, Pb-rich particles were classified into Pb-O-Cl-N-S (55%), Pb-N (17%), Pb-N-S (15%), and Pb-EC (7%). Residual coal combustion, industrial activities, and meteorological conditions were identified as main factors regulating the variations of Pb-rich particles in the atmosphere. The highest abundance of the Pb-rich particles was observed during heating period (HP) primarily due to the increase in coal usage. Pb in Pb-O-Cl-N-S type was identified in forms of PbO, PbCl2, and Pb(NO3)2. Dominantly presented in the form of Pb(NO3)2, Pb-N type represented the completely transformed Pb-rich particles from PbO/PbCl2 by atmospheric processes. It is found that PbCl2 and PbO could be transformed to Pb(NO3)2, highly dependent on the amount of NO2 and RH. Significant enhancement of nitrate in Pb-O-Cl-N-S particles was observed when the RH was greater than 60%, emphasizing the importance of heterogeneous hydrolysis of N2O5 on the formation of Pb(NO3)2. Compared with non-carcinogenic PbCl2/PbO and insoluble PbO, soluble and carcinogenic Pb(NO3)2 produced by atmospheric processes may significantly enhance negative effects of Pb-rich particles on human health and the ecosystem.

7.
Chemosphere ; 238: 124863, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31551201

RESUMO

Peripheral blood leukocyte telomere length in omethoate-exposed workers is related to environmental exposure and single nucleotide polymorphisms (SNPs) in genes including p21, GSTM1, miR-145, etc. However, the roles of SNPs in tankyrase (TNKS) gene in telomere length are still unknown. The aim of this study was to explore the association between SNPs in TNKS gene and telomere length in omethoate-exposed workers. Telomere length in peripheral blood leukocyte DNA from 180 omethoate-exposed workers and 115 healthy controls was measured using Real-time quantitative polymerase chain reaction (PCR). Genotyping of the selected functional and susceptible SNPs was performed by the flight mass spectrometry based on PCR and single-base extension. The analysis of covariance was performed to find effects of SNPs on telomere length. Generalized linear models were used to analyze the environment, gene, and interaction on telomere length. The results showed that telomere length in the CG + CC genotypes in rs1055328 in TNKS gene was significantly longer than that in the wild homozygous GG genotype both in exposure group (P = 0.017) and in control group (P = 0.038) after adjusting the covariates. The variables kept in the generalized linear models included omethoate-exposure (ß = 0.580, P = 0.001) and rs1055328 (CG + CC) in TNKS gene (ß = 0.339, P = 0.002). The study suggests that the prolongation of telomere length is associated with omethoate-exposure and the CG + CC genotypes in rs1055328 in TNKS gene.

8.
World J Surg Oncol ; 17(1): 174, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31672152

RESUMO

BACKGROUND: Pathologically confirmed brain metastasis from primary cervical cancer is extremely rare. Herein, we report two cases of intracranial metastasis from cervical cancer that were histopathologically confirmed after surgical excision. In addition, we conducted a literature review to characterize the clinical manifestation, pathogenesis, and treatment of these patients. Among the 1800 patients with primary cervical cancer who received therapy at our center from 2010 to 2018, two patients (0.1%) had definite histopathological evidence of brain metastasis. A 46-year-old female who had a history of poorly differentiated stage IIB cervical cancer with neuroendocrine differentiation presented with a solitary mass in the right occipital lobe 26 months after the initial diagnosis. She underwent surgery and chemotherapy but died of disease progression 9 months later. Another 55-year-old female diagnosed with poorly differentiated stage IVB cervical squamous cancer presented with a solitary mass in the right frontal lobe 16 months after simple hysterectomy. Twelve months later, multiple lesions were observed in the bilateral frontal-parietal lobe. The lesions were treated by surgery and stereotactic radiosurgery. The patient died of multiple organ failure 14 months later. CONCLUSION: The pathogenesis and best management of brain metastasis from cervical cancer are not clear. Highly invasive subtypes or advanced cancer stages may be the key clinicopathological factors of brain metastasis. Surgical treatment is warranted in patients with a good health status and without metastasis to other sites.

9.
Appl Opt ; 58(27): 7375-7378, 2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31674386

RESUMO

In this paper, an integrated processing method was demonstrated to fabricate the polymer-based thermo-optic (TO) switch with low power consumption. The characteristic parameters of the switch were carefully designed and simulated. The air trench structure was exploited to reduce the power consumption, which can be formed with the waveguide simultaneously by the integrated processing method. Moreover, the introduced polymer/silica hybrid waveguide structure can also improve the response time of the device. A typical fabricated switch presented a low switching power of 5.2 mW. The measured switching rise time and fall time are 192.2 and 201.1 µs, respectively.

10.
J Exp Bot ; 2019 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-31677347

RESUMO

Neighbor detection and allelochemical response are important mediators in plant-plant interactions. Despite increasing knowledge of plant allelochemicals in response to the presence of competitors involved in the neighbor-derived signaling chemicals, less is known about which signaling chemicals are responsible for the neighbor-induced allelochemical response. Here, we experimentally demonstrated (-)-loliolide, a carotenoid metabolite, as a signaling chemical in barnyardgrass-rice allelopathic interactions. The production of rice allelochemicals momilactone B and tricin was increased in the presence of five biotypes of barnyardgrass. (-)-Loliolide was found in all biotypes of barnyardgrass and their root exudates and rhizosphere soils. There were significant positive relationships between rice allelechemicals and (-)-loliolide concentrations across biotypes of barnyardgrass. Furthermore, (-)-loliolide elicited the production of momilactone B and tricin. Comparative transcriptome analysis showed regulation of (-)-loliolide on diterpenoid and flavonoid biosynthesis pathway. The expression of key genes involved in the biosynthesis of momilactone B (CPS4, KSL4 and MAS) and tricin (CYP75B3 and CYP75B4) was up-regulated by (-)-loliolide. These findings suggest that (-)-loliolide as a signaling chemical participates in barnyardgrass-rice allelopathic interactions. Through the signaling chemical, allelopathic rice plants can detect competing barnyardgrass and respond by increasing allelochemical levels to provide an advantage for their own growth.

11.
Science ; 366(6467)2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31672918

RESUMO

Gastrulation is a key event in embryonic development when the germ layers are specified and the basic animal body plan is established. The complexities of primate gastrulation remain a mystery because of the difficulties in accessing primate embryos at this stage. Here, we report the establishment of an in vitro culture (IVC) system that supports the continuous development of cynomolgus monkey blastocysts beyond early gastrulation up to 20 days after fertilization. The IVC embryos highly recapitulated the key events of in vivo early postimplantation development, including segregation of the epiblast and hypoblast, formation of the amniotic and yolk sac cavities, appearance of the primordial germ cells, and establishment of the anterior-posterior axis. Single-cell RNA-sequencing analyses of the IVC embryos provide information about lineage specification during primate early postimplantation development. This system provides a platform with which to explore the characteristics and mechanisms of early postimplantation embryogenesis in primates with possible conservation of cell movements and lineages in human embryogenesis.

12.
Oncogene ; 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31676872

RESUMO

Colorectal cancer (CRC) is a common cancer type and a threat to human health. Tumor budding (TB) is the presence of a single cancer cell or clusters of up to five cancer cells prior to the invasive front of an aggressive carcinoma and is an independent prognosis factor for CRC. The molecular mechanism of TB is still unclear, and drugs that inhibit this process are still in the blank stage. This study found that TBs exhibit characteristics of partial EMT with a decreased expression of E-cadherin and no substantial differences in the expression of N-cadherin and vimentin. We also observed the interaction of integrin with extracellular matrix components, laminin-5γ2 (LN-5γ2), play essential roles in the TB of CRC. We then verified that the interaction between LN-5γ2 and integrin ß1 promotes the TB of CRC via the activation of FAK and Yes-associated proteins (YAP). A natural drug monomer, cucurbitacin B, was screened using virtual screening methods for the interaction interface of proteins. We found that this monomer could block the interaction interface between LN-5γ2 and integrin ß1 and substantially inhibit the TB of CRC cells via inactivation of YAP. This study provides new insights into the mechanism of TB mechanism and the development of drugs targeting the TB of CRC.

13.
Nat Commun ; 10(1): 5181, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31729358

RESUMO

Dry reforming of methane (DRM) is an attractive route to utilize CO2 as a chemical feedstock with which to convert CH4 into valuable syngas and simultaneously mitigate both greenhouse gases. Ni-based DRM catalysts are promising due to their high activity and low cost, but suffer from poor stability due to coke formation which has hindered their commercialization. Herein, we report that atomically dispersed Ni single atoms, stabilized by interaction with Ce-doped hydroxyapatite, are highly active and coke-resistant catalytic sites for DRM. Experimental and computational studies reveal that isolated Ni atoms are intrinsically coke-resistant due to their unique ability to only activate the first C-H bond in CH4, thus avoiding methane deep decomposition into carbon. This discovery offers new opportunities to develop large-scale DRM processes using earth abundant catalysts.

14.
J Am Chem Soc ; 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31722172

RESUMO

A missing source of sulfate production associated with high-level fine-particle pollution in megacities of Asia is believed to stem from oxidation of a notable fraction of sulfur dioxide (SO2) by nitrogen dioxide (NO2) in aqueous aerosol environment, suggesting an unknown reaction pathway for the aqueous sulfur oxidation. The estimated pH values of haze aerosols range from about 4 to 7 from previous studies. At the low-end pH value (for weakly acidic aerosols), the dissolved SO2 mainly exists in the form of HSO3- whereas at the high-end pH value (for neutral aerosols), SO32- becomes the main form. Herein, by using both ab initio molecular metadynamics simulation and high-level quantum mechanical calculations, we show a hith-erto unreported chemical mechanism for the formation of sulfate through the reaction between HSO3-/SO32- anions, at the surface/interior of water droplet, and the gas-phase NO2 molecules. For weakly acidic aerosol, contrary to the conventional high-barrier electron-transfer pathway in the gas phase, HSO3- at the surface of water droplet can transfer electron to NO2 with a low energy barrier of 4.7 kcal/mol through a water bridge triggered by the NO2 molecule. The electron transfer can simultaneously promote the O-H bond dissociation in HSO3- to form SO3-. For neutral aerosol, the electron transfer pathway between SO32- in the interior of water droplet and NO2 molecule only needs to overcome a lower energy barrier of 3.6 kcal/mol to form SO3-, with the assistance of the hydrogen-bonding network of water molecules. In either acidic or neutral aerosol, the SO3- can react with another NO2 molecule to form the NO2SO3‾ specie, followed by forming bisulfate HSO4- and HONO (HNO2) with another water molecule. The free-energy barrier of 5.8 kcal/mol is much lower than that associated with the gas-phase reaction. This new reaction pathway to the sulfate formation from HSO3-/SO32- in water nanodroplet and the gaseous NO2 provide a new perspective on the growth of haze particles from preexisting aqueous aerosols, thereby benefiting new pollution-control strategies to resolve the haze problem.

15.
Biosci Rep ; 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31670380

RESUMO

Fasudil is a derivative of 5-isoquinoline sulfonamide, which is a Rho kinase inhibitor, a wide range of pharmacological effects. Fasudil has been shown to attenuate kidney injury caused by certain substances. In the present study, metabolomic analysis of mouse kidney tissues ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry was used to determine the metabolomic changes in cisplatin-induced kidney injury and the fasudil-induced attenuation of cisplatin-induced kidney injury. Metabolomic profiling of kidney tissues revealed significant differences in metabolites between the control group and the cisplatin group and between the cisplatin group and the fasudil-intervention group. With metabolomic approach, 68 endogenous differential metabolites were found, and multivariate statistical analysis, accurate molecular weights, isotope tracers, mass-spectrometry secondary-fragment information, and standard-reference comparisons were used to identify these substances. Based on these differential metabolites, a metabolic-pathway network was constructed and revealed that fasudil primarily attenuated cisplatin-induced renal injury by modulating lipid and amino-acid metabolism. These results further demonstrate that kidney injury can be induced by cisplatin and, moreover, suggest that fasudil can be used to reduce kidney injury at early stages in patients treated with cisplatin.

16.
Opt Express ; 27(21): 29770-29780, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31684234

RESUMO

We report on experimental generation and evolution of circumstance-susceptible, narrow-bandwidth, h-shaped pulse in a thulium-doped fiber (TDF) laser. With typical mode-locking technique based on nonlinear amplifying loop mirror, a type of h-shaped pulse is generated in a net normal dispersion regime for the first time to our best knowledge. Different from pulses with similar profiles achieved in typical anomalous dispersion regime, the h-shaped pulse here exhibits extremely narrow spectral bandwidth and meanwhile becomes highly circumstance-susceptible. Not alike the well-preserved h-shaped profile with anomalous dispersion, here the h-shaped pulse can easily evolve into various other pulse patterns with circumstance variations, including peak-depressed profiles, burst-like emission, multiple h-shaped pulses, and even some highly complex temporal cases. Despite that, the h-shaped pulse broadens as the pump power increasing, being a typical pump-related characteristic dominated by the peak-power-clamping effect. Moreover, it is observed that the h-shaped pulse profile can be re-shaped by incorporating a piece of unpumped TDF into the cavity, i.e., introducing some reabsorption. Our results substantiate the experimental revelation of such a type of particular-profile pulse in the normal dispersion regime, demonstrating some new evolution features facilitated by the dispersion-relevant circumstance-susceptibility.

17.
Opt Express ; 27(20): 29287-29296, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31684665

RESUMO

Laser damage thresholds (Ith) at 1.03 µm, as well as third-order nonlinear refractive indices (n2) and two photon absorption coefficients (ß) at 1.55 µm of a number of Ge-As-S glasses were measured and systematically studied. The glass with the composition Ge0.12As0.24S0.64 showed a high Ith and the maximum figure of merit (fm= n2/(ß·λ)), and therefore was selected as the core material for the fabrication of a step-index fiber. A compatible glass with the composition Ge0.18As0.1S0.72 was chosen as the cladding material. Based on the dispersion calculations, the fiber with a core diameter of ∼7-10 µm was designed. The designed fiber was fabricated by a multiple step rod-in-tube method. When the fiber with a core diameter of ∼9 µm and a length of ∼13.5 cm was pumped by ∼170 fs pulses (1 MHz) at 4.5 µm, the mid-infrared supercontinuum (SC) covering 1.3-8.1 µm was generated. These results demonstrate the good potential of Ge-As-S chalcogenide fibers for producing high-brightness broadband mid-infrared SC light sources.

18.
Urol Oncol ; 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31672485

RESUMO

OBJECTIVE: Docetaxel-based chemotherapy remains the first-line treatment for patients with metastatic castration-resistant prostate cancer (mCRPC) in China. We have previously shown that time to nadir (TTN) of prostate-specific antigen (PSA) is an important prognostic factor in patients from a single center in Northwestern China. In this study, we performed a multicenter validation of the prognostic role of TTN in additional Chinese patients with mCRPC receiving docetaxel treatment. MATERIALS AND METHODS: The data were gathered from 170 eligible Chinese patients who received docetaxel chemotherapy from January 2007 to October 2018 in 11 Chinese Prostate Cancer Consortium member hospitals in China. TTN was defined as the time from start of chemotherapy to the nadir of PSA level during the treatment. Multivariable Cox regression models and Kaplan-Meier analysis were used to predict overall survival (OS) and progression-free survival (PFS). RESULTS: Patients with a TTN ≥ 15 weeks had a longer OS and PFS compared to those with a TTN < 15 weeks (43 vs. 15 months, P < 0.001; 24 vs. 6 months, P < 0.001, respectively). In addition, Patients with a TTN ≥ 15 weeks and PSA nadir <4.55ng/ml were associated with longer OS than others (HR 0.093, 95% CI 0.044-0.188, P < 0.001; HR 4.002, 95% CI 1.890-8.856, P = 0.001, respectively) and TTN, PSA nadir, PSA baseline (optimal threshold 56.07 ng/ml), and PSA reduction (optimal threshold 50%) were associated with PFS (HR 0.238, 95% CI 0.149-0.382, P < 0.001; HR 1.676, 95% CI 1.033-2.722, P = 0.037; HR 1.770, 95% CI 1.134-2.763, P = 0.012; HR 0.573, 95% CI 0.428-0.756, P < 0.001; respectively). Furthermore, patients with a PSA nadir <4.55 ng/ml had longer OS and PFS compared to other patients when TTN was ≥15 weeks. CONCLUSION: In this multicenter validation study, TTN and PSA nadir remain important prognostic markers in predicting therapeutic outcomes in Chinese men who receive chemotherapy for mCRPC.

19.
Biomed Pharmacother ; 121: 109548, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31704612

RESUMO

BACKGROUND: 15-Lipoxygenase-1 (15-LOX-1) belongs to the lipoxygenase family involved in the inflammatory response and pathological process of various diseases, including osteoarthritis (OA). The overexpression of TGF-ß1 in osteoblasts leads to abnormal changes in subchondral bone structure, eventually causing OA. However, the pathogenesis of the disease is poorly defined, and the interaction between 15-LOX-1 and TGF-ß1 in osteoblasts has not been evaluated in OA. In this study, the role of 15-LOX-1 in subchondral bone osteoblasts in OA was evaluated. METHOD: 15-LOX-1 expression in osteoblasts of the subchondral bone of patients with OA was measured by immunohistochemistry, qRT-PCR, and western blotting. Osteoblasts extracted from the subchondral bone of OA were transfected with 15-LOX-1 siRNA and an overexpression vector. The eff ;ect of 15-LOX-1 on the expression of TGF-ß1 in OA osteoblasts was assessed by qRT-PCR and western blotting. The effect of 15-LOX-1 on autophagy via AMPK pathway in OA osteoblasts was evaluated by qRT-PCR, western blotting, and transmission electron microscopy. RESULTS: The expression levels of 15-LOX-1 and TGF-ß1 were higher in OA subchondral bone osteoblast than that in non-OA subchondral bone. 15-LOX-1, which downregulated autophagy by inhibiting AMPK following the activation of mTORC1, upregulated the osteoblast expression of TGF-ß1. Treatment with autophagy inhibitors significantly increased the expression levels of TGF-ß1 in osteoblasts. CONCLUSION: In the present study, our findings suggested that 15-Lipoxygenase-1 in Osteoblasts Promotes TGF-ß1 expression via inhibiting autophagy in human Osteoarthritis. These novel results suggested that 15-Lipoxygenase-1 expressed by subchondral bone osteoblasts might be a promising therapeutic target in human OA.

20.
Mikrochim Acta ; 186(12): 755, 2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31707595

RESUMO

Platinum nanoparticles were loaded on CoSn(OH)6 nanocubes via a co-precipitation method. The material (NCs) is shown to be a viable peroxidase mimic that catalyzes the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by hydrogen peroxide (H2O2) to generate oxidized TMB (oxTMB) with absorption at 652 nm. The formation of the blue color can be observed in <30 s. Thus, a visual and colorimetric assay was worked out for H2O2. It has a detection limit as low as 4.4 µM and works in the 5 to 200 µM concentration range. The method was also used to detect dopamine (DA) which is found to inhibit the enzyme mimicking activity of the NCs. Hence, less blue color is formed in its presence. The respective DA assay has a linear response in the 5.0 to 60 µM concentration range and a 0.76 µM detection limit. Graphical abstractSchematic diagram of a visual colorimetric method for determination of H2O2 and dopamine (DA) with the aid of color change of 3,3',5,5'-tetramethylbenzidine (oxTMB), based on the peroxidase-like activity of Pt/CoSn(OH)6 nanocubes.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA