Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 90
Filtrar
1.
Sensors (Basel) ; 24(6)2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38544221

RESUMO

The BeiDou Navigation Satellite System (BDS) provides real-time absolute location services to users around the world and plays a key role in the rapidly evolving field of autonomous driving. In complex urban environments, the positioning accuracy of BDS often suffers from large deviations due to non-line-of-sight (NLOS) signals. Deep learning (DL) methods have shown strong capabilities in detecting complex and variable NLOS signals. However, these methods still suffer from the following limitations. On the one hand, supervised learning methods require labeled samples for learning, which inevitably encounters the bottleneck of difficulty in constructing databases with a large number of labels. On the other hand, the collected data tend to have varying degrees of noise, leading to low accuracy and poor generalization performance of the detection model, especially when the environment around the receiver changes. In this article, we propose a novel deep neural architecture named convolutional denoising autoencoder network (CDAENet) to detect NLOS in urban forest environments. Specifically, we first design a denoising autoencoder based on unsupervised DL to reduce the long time series signal dimension and extract the deep features of the data. Meanwhile, denoising autoencoders improve the model's robustness in identifying noisy data by introducing a certain amount of noise into the input data. Then, an MLP algorithm is used to identify the non-linearity of the BDS signal. Finally, the performance of the proposed CDAENet model is validated on a real urban forest dataset. The experimental results show that the satellite detection accuracy of our proposed algorithm is more than 95%, which is about an 8% improvement over existing machine-learning-based methods and about 3% improvement over deep-learning-based approaches.

2.
J Viral Hepat ; 30(5): 437-447, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36695325

RESUMO

The utility of measurement of serum immunoglobulin and complement in chronic hepatitis B (CHB) patients remains controversial. This study aimed to investigate the association of serum immunoglobulin and complement levels and liver fibrosis and inflammation stage in CHB patients. A total of 687 patients with CHB who underwent liver biopsy were enrolled. Serum immunoglobulin and complement were measured before liver biopsy, and liver pathological results were recorded. Associations of serum immunoglobulin and complement levels and liver fibrosis and inflammation stage were analysed. C3, C4, IgG and IgG1 had statistically significant differences among different fibrosis and different inflammation groups. Both C3 and C4 negatively correlated with fibrosis and inflammation stage, but IgG and IgG1 showed opposite results. C3, C4, IgG and IgG1 had statistical significance to predict ≥S2, ≥S3 and S4, and also had statistical significance to predict ≥G2, ≥G3 and G4. The area under curve (AUC) of the combination of C3, C4 and IgG (C3 + C4 + IgG) for predicting ≥S2, ≥S3 and S4 was 0.640 (95% CI: 0.603, 0.676), 0.674 (95% CI: 0.638, 0.709) and 0.744 (95% CI: 0.710, 0.776), respectively. The AUC of C3 + C4 + IgG for predicting ≥G2, ≥G3 and G4 was 0.723 (95% CI: 0.688, 0.756), 0.674 (95% CI: 0.638, 0.709) and 0.771 (95% CI: 0.738, 0.802), respectively. C3, C4, IgG and IgG1 are correlated with liver fibrosis and inflammation stage in CHB patients. C3, C4, IgG and IgG1 have diagnostic value for liver fibrosis and inflammation. C3 + C4 + IgG may improve diagnostic accuracy.


Assuntos
Hepatite B Crônica , Humanos , Cirrose Hepática/diagnóstico , Cirrose Hepática/patologia , Inflamação , Fibrose , Imunoglobulina G , Complemento C4
3.
Molecules ; 28(7)2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-37050041

RESUMO

As a star material in conducting polymers, a polypyrrole coating was assembled onto the surface of 316 stainless steel by an electrochemical method. In the next step, the composite layer consisting of carbon nitride nanosheets (CNNS) and polymethyl methacrylate (PMMA) was sprayed. The corrosion manner of composite coatings in a simulated proton-exchange membrane fuel cell (PEMFC) environment was evaluated. The results show that the final coating generated at a voltage of 1.0 has demonstrated the optimized corrosion resistance. The polypyrrole layer improves the corrosion resistance of the stainless steel substrate, and the CNNS/PMMA coating further strengthens the physical barrier effect of the coating in corrosive solutions.

4.
Inorg Chem ; 61(9): 4159-4170, 2022 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-35188743

RESUMO

In this work, three different sulfur sources such as sulfur powder, sodium sulfide, and sodium thiosulfate are selected to prepare sulfur-derived quantum dots (S-QDs), Na2S-derived nanoparticles (NS-NPs), and Na2S2O3--derived QDs (NSO-QDs) in the presence of NaOH or assisted by hydrogen peroxide etching. The low sulfur percentage in the above three samples and the synthesis experiments in the presence of nitrogen/oxygen all support that poly(ethylene glycol) (PEG) plays an important role during the assembly process and the definition of sulfur dots is not accurate. For photophysical features, remarkable green quantum dots (S-QDs) possess an excitation-independent emission peak at 500 nm. But NS-NPs and NSO-QDs demonstrate observable shift tendency, and the evolution of emission profiles varies from 480 to 586 nm. NSO-QDs can be used as a fluorescent probe for highly selective and quantitative detection of Ni2+ in an aqueous solution in the presence of potential interfering ions with a low detection limit (0.18 µM) and a wide linear range (8-380 µM). Their reusability performance has also been demonstrated by employing dimethylglyoxime as the restoration reagent.

5.
Inorg Chem ; 61(44): 17883-17892, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36302095

RESUMO

The strategy to enhance phosphor stability against thermal quenching and moisture conditions will contribute to controlling the feature of phosphor-converted white-light-emitting diodes (pc-WLEDs). Herein, an effective strategy is achieved with the incorporation of Sm3+ ions, and a robust reddish-orange emission (no thermal quenching up to 498 K) is obtained based on Ba3LaNb3O12 as a host. In light of excitation by near-ultraviolet irradiation at 408 nm, Ba3LaNb3O12:Sm3+ gives rise to a typical signal ascribed to the 4G5/2 → 6HJ/2 (J = 5, 7, 9, and 11) transitions of Sm3+ ions. The concentration quenching effect is observed when the Sm3+ content exceeds 10%, and the quenching mechanism is caused by electronic dipole-dipole interactions. Based on the narrow emission curves, a very high color purity (92.4%) could be recorded. The Sm3+ substitution at the Ba2+/La3+ site leads to a rigid structural lattice and abundant electron-trapping centers for the Sm3+ ions, which will be responsible for the zero-thermal-quenching phenomenon. In addition, oleic acid (OA) is selected to form a hydrophobic covering surface structure to protect Ba3LaNb3O12:Sm3+, which can assist in improving the moisture resistance. The most favorable parameters concerning the warm-light emission (a high general color rendering index, Ra, of 85.7 and a low correlated color temperature, CCT, of 4965 K) can be achieved in pc-WLEDs containing an OA-modified sample. Moreover, its luminous efficiency, LE, can maintain 82.9% of its initial value after 120 h under controlled environmental conditions of 85 °C and 85% humidity. These results pave a new way to optimize the sample as a potential candidate for red-emitting materials.

6.
Inorg Chem ; 61(51): 21157-21168, 2022 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-36520141

RESUMO

Treatment of sulfur dots with polyethylene glycol (PEG) has been an efficient way to achieve a high luminescence quantum yield, and such a PEG-related quantum dot (QD)-synthesis strategy has been well documented. However, the polymeric insulating capping layer acting as the "thick shell" will significantly slow down the electron-transfer efficiency and severely hamper its practical application in an optoelectric field. Especially, the employment of synthetic polymers with long alkyl chains or large molecular weights may lead to structural complexity or even unexpected changes of physical characteristics for QDs. Therefore, in sulfur dot preparation, it is a breakthrough to use short-chain molecular species to replace PEG for better control and reproducibility. In this article, a solvent-type passivation (STP) strategy has been reported, and no PEG or any other capping agent is required. The main role of the solvent, ethanol, is to directly react with NaOH, and the generated sodium ethoxide passivates the surface defects. The afforded STP-enhanced emission sulfur dots (STPEE-SDs) possess not only the self-quenching-resistant feature in the solid state but also the extension of fluorescence band toward the wavelength as long as 645 nm. The realization of sulfur dot emission in the deep-red region with a decent yield (8.7%) has never been reported. Moreover, a super large Stokes shift (300 nm, λex = 345 nm, λem = 645 nm) and a much longer decay lifetime (109 µs) have been found, and such values can facilitate to suppress the negative influence from background signals. Density functional theory demonstrates that the surface passivation via sodium ethoxide is dynamically favorable, and the spectroscopic insights into emission behavior could be derived from the passivation effect of the sulfur vacancy as well as the charge-transfer process dominated by the highly electronegative ethoxide layer.


Assuntos
Pontos Quânticos , Solventes , Reprodutibilidade dos Testes , Pontos Quânticos/química , Polietilenoglicóis/química , Polímeros , Enxofre
7.
Sensors (Basel) ; 22(16)2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-36015863

RESUMO

To address the challenges in the unmanned system-based intelligent inspection of electric transmission line insulators, this paper proposed a multi-geometric reasoning network (MGRN) to accurately detect insulator geometric defects based on aerial images with complex backgrounds and different scales. The spatial geometric reasoning sub-module (SGR) was developed to represent the spatial location relationship of defects. The appearance geometric reasoning sub-module (AGR) and the parallel feature transformation (PFT) sub-module were adopted to obtain the appearance geometric features from the real samples. These multi-geometric features can be fused with the original visual features to identify and locate the insulator defects. The proposed solution is assessed through experiments against the existing solutions and the numerical results indicate that it can significantly improve the detection accuracy of multiple insulator defects using the aerial images.

8.
Molecules ; 27(14)2022 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-35889303

RESUMO

The presence of nitrite (NO2-) in water and food leads to serious problems in public health and the environment. Therefore, it is important to develop a rapid and efficient method for the selective detection of NO2-. In this work, the synthesis and characterization of magnetic Fe3O4@SiO2-TbDPA nanoprobe have been carried out. The Fe3O4@SiO2-TbDPA aqueous solution exhibits a strong green emission. Due to the addition of various concentrations of NO2- (0-100 µM), the fluorescence intensity has been suppressed. The nanoprobe Fe3O4@SiO2-TbDPA exhibits excellent selectivity and sensitivity toward NO2- ions. Excellent linearity is obtained in the range of 5-80 µM with a detection limit of 1.03 µM. Furthermore, the presence of magnetic Fe3O4 nanoparticles in Fe3O4@SiO2-TbDPA nanospheres will also facilitate the effective separation of Fe3O4@SiO2-TbDPA from the aqueous solution. Our proposed strategy is expected to fabricate an organic-inorganic hybrid magnetic nanomaterial and can be used as an efficient sensor. It has been shown that this new strategy has numerous advantages, such as high stability, selectivity, and simplicity of operation. It demonstrates great potential for simple and convenient NO2- detection. It may expand to a variety of ranges in environmental monitoring and biomedical fields.


Assuntos
Elementos da Série dos Lantanídeos , Nanosferas , Nitritos , Dióxido de Nitrogênio , Dióxido de Silício
9.
Inorg Chem ; 60(21): 16507-16517, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34647450

RESUMO

Single-phase phosphors with tunable emission colors are crucial to develop high-performance white light-emitting diodes since they are valuable to improve the energy efficiency, color rendering index, and correlated color temperature. Most of the studies have been conducted to control the spectral shifts via a polyhedral distortion or chemical unit cosubstitution strategy. The combination of host optimization and dopant activator design in a single-phase phosphor system is very rare. Herein, a partial substitution strategy of [Ba2+-Gd3+] by [Sr2+-Lu3+] has been employed in Ba4-xSrxGd3-x-yLuxNa3(PO4)6F2/5% Eu2+ (x = 0-0.40) phosphors. Also, the energy migration from Eu2+ to Tb3+ ions has been investigated in as-prepared samples. Consequently, the emitted signal is observed to shift from 470 to 575 nm derived from equivalent substitutions, which is attributed to specific performance by the emission profile of Eu2+, and such results are closely related to splitting of the crystal field and energy transfer among various luminescent centers. Moreover, the tunable yellowish-green emitting material has been assembled by incorporating ion pairs (Eu2+ → Tb3+) into the Ba3.85Sr0.15Gd2.85Lu0.15Na3(PO4)6F2, and their relative ratios are varied. The corresponding Eu2+ → Tb3+ energy migration process is assigned to be the dipole-quadrupole interaction by the Inokuti-Hirayama model. This work provides rational guidance for the design and discovery of new products with tunable emission colors, originating from the cosubstitution strategy and energy conversion model.

10.
Inorg Chem ; 60(24): 19315-19327, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34851618

RESUMO

The influence of temperature on a variety of physiological or chemical processes has generated considerable interest, and recently noninvasive lanthanide-incorporated optical thermometers have been considered as promising candidates for monitoring its changes at different scales. Herein, a novel Bi3+-activated Sr3-xGdxGaO4+xF1-x phosphor with tunable color has been constructed by a cooperative cation-anion substitution strategy with to the replacement of [Sr2+-F-] by [Gd3+-O2-]. When x = 0, the sample Sr3GaO4F/Bi3+ possesses a peak wavelength at 438 nm, and this value will shift to 470 nm if x is equal to 1 (Sr2GdGaO5/Bi3+). In addition, photoluminescence tuning from blue to red has been realized successfully by an efficient Bi3+ → Eu3+ energy migration model in Sr2.6Gd0.4GaO4.4F0.6 samples. The specific Bi3+ → Eu3+ energy transfer has been explained by dipole-dipole interactions derived from a model of the Dexter pathway. Intriguingly, the two dopants (a blue signal from Bi3+ and a red signal from Eu3+) possess different thermal responses to increasing temperature. Accordingly, the intensity ratio values are sensitive to the temperature changes. The energy level cross relaxation causes the quenching effect of Bi3+, and the multi-phonon de-excitation mode leads to the thermal quenching of Eu3+. At room temperature (298 K), the determined maximum relative sensitivity (Sr) is 1.27% K-1. Moreover, the absolute sensitivity (Sa) is 0.067 K-1 since the temperature is elevated to 523 K. The collected results are superior to most of the reported optical thermometry materials.

11.
J Fluoresc ; 31(3): 695-702, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33582949

RESUMO

Inorganic-organic optical probe based on lanthanide emission will provide a new way for specific applications. In this work, sarcosine and urea are selected as raw materials to synthesize carbon dots with cyan-emissive color. In the next step, indicator components (Ethylene Diamine Tetraacetic Acid and lanthanide ions) are incorporated onto carbon quantum dots (CQDs) and the flexible alginate hydrogel is employed as the host to accommodate the emissive species. The soft material can exhibit typical red and green emissions. Its luminescence is responsive to calcium ions and the detection limit has been calculated to be 0.84 µM and 0.92 µM respectively. Such optical device can be employed as a portable probe in a variety of scientific fields due to its convenience and flexibility.

12.
J Fluoresc ; 31(4): 1125-1132, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33974179

RESUMO

The new design strategy will provide the possibility for preparing a dynamic sensor by employing the inhibition of C = N isomerization. In this work, the functional probe 4-(1 H-imidazo [4,5-f] [1,10]-phenanthrolin-2-yl) benzaldehyde oxime (compound 4) has been synthesized and such molecule gives rise to blue emission. Due to the incorporation of hypochlorite, the oxime group can be oxidized to the structure of aldehyde. As a result, the molecular motif exhibits sharp emission change from blue to green due to the addition of hypochlorite with enough sensitivity and selectivity (detection limit = 53 nM, linear range 0.5-8.0 µM). It has also been used for monitoring ClO- by employing solution color change and the absorption signal difference could effectively rule out the effects of interference species. To our knowledge, it will be the first case of a highly selective hypochlorite sensor derived from oxime isomerization reaction based on phenanthroline backbone.

13.
Inorg Chem ; 59(20): 15514-15525, 2020 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-33030016

RESUMO

The most critical aspect in the assembly of phosphor-converted white light-emitting diodes (pc-WLEDs) is how to stabilize the device in a practical environment. The high applied currents can generate enormous heat up to more than 100 °C, and such a continuous illumination process will lead to serious effects concerning the stability of the device. Therefore, the new search for examples to fully suppress thermal quenching effect is a real challenge. In this study, a novel Eu3+-activated CaMgGeO4 (CMGO) phosphor of olivine type is developed via a conventional solid-state reaction. The results reveal that Eu3+ occupies the low symmetric Ca2+ site of this host. Upon visible-light sensitization at 464 nm, a dominant red emission band with maximum at 612 nm is witnessed. Its full width at half-maximum (fwhm) is merely ∼4.37 nm, and a high color purity of around 94% is achieved. Their corresponding Commission Internationale de L'Eclairage (CIE) coordinates are very close to standard red color coordinates (0.666, 0.333). The influence of concentration and temperature on the optical property has been explored. It has been discovered that the optimized sample (CMGO:0.01Eu3+) is not influenced by the thermal quenching effect and its fluorescent intensity is improved even up to 473 K, which is mainly attributed to the incorporation of abundant trap sites generated by the nonequivalent substitution Eu3+ for Ca2+. After it is integrated into commercially available YAG:Ce3+ phosphor-based pc-WLEDs, the excellent optical parameters of the fabricated WLEDs are evaluated. The correlated color temperature (CCT) varies from cool white (6458 K) to warm (4370 K), and the color rendering index (CRI) increases from 78 to 86 under a high flux operating current of 200 mA. Furthermore, the chromaticity coordinates remain almost stable with the increasing drive current from 200 mA to 1000 mA. It is highly expected that CaMgGeO4:0.01Eu3+ will become a suitable red phosphor for the preparation of white LEDs with high efficiency.

14.
Inorg Chem ; 59(1): 433-442, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31829630

RESUMO

The substitution of metal sites in Mg2TiO4 substrate leads to charge imbalance that will be closely related to a variety of changes including lattice structure, cell distortion, and photophysical properties. Herein, the co-substitution strategy of [Ga3+-Ga3+] for [Mg2+-Ti4+] and Sn4+ for Ti4+ achieves for the first time the novel Mg3Ga2SnO8 (MGS):xMn4+ (x = 0-3%) phosphors with efficient red emissions. In terms of X-ray powder diffraction (XRD) and Rietveld refinement analysis, MGS:Mn4+ possesses a structure isotypic of Mg2TiO4 in the cubic space group Fd3̅m (227). There are two types of octahedra for Mn4+ ions in this structure, where Ga3+ ions completely occupy a group of octahedral sites and Mg2+/Sn4+ has been randomly distributed over another group of octahedral sites. A strong excitation band in the broad spectral range (220-550 nm) has been identified, thus facilitating the commercial uses for blue LED chips excitation. An intense red emission band at 680 nm has been observed due to the characteristic 2Eg-4A2g transition of Mn4+ ions. A concentration quenching effect occurs when the Mn4+ content exceeds 1.5%, and the quenching mechanism is demonstrated to be dipole-quadrupole interactions. Temperature-dependent luminescence measurements support its good thermal stability, and the corresponding activation energy Ea is determined to be 0.2552 eV. The possible luminous mechanism of the Mn4+ ion is explained by the Tanabe-Sugano energy level diagram. The crystal field strength and the Racah parameters together with the nephelauxetic ratio are also determined for Mn4+ in the MGS lattice. High color rendition warm white-light-emitting diodes (WLEDs) based on the optimal phosphor MGS:1.5%Mn4+,1.5%Li+ possess a color rendering index and color temperature of 85.6 and 3658 K, respectively. Its feasibility for application in solid-state white lighting has been verified.

15.
Mikrochim Acta ; 187(6): 313, 2020 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-32377952

RESUMO

A low-molecular-weight molecule (4-(2-(3-(dicyanomethyl)-5,5-dimethylcyclohex-1-en-1-yl)vinyl)phenyl-benzoate, DDPB) has been developed. The organic framework possesses very weak fluorescence . The feasibility of the signal transduction has been performed via fluorometric titrations in solution. DDPB gives rise to responses to carboxylesterase 2 (CES2) based on "off-on" responses. The red emission at 670 nm has been derived from the enzyme-induced hydrolysis of ester linkages, thus suppressing the intramolecular charge transfer (ICT) effect and thereby generating the fluorescent segment. The optical excitation window for this probe is extended to the visible light range (λex = 516 nm), and it will induce less harmful influence on biological substances. The detection limit for the measurement of CES2 concentration is as low as 2.33 mU/mL. The conventional studies concerning the activation process are generally performed within only a single liveing cell system. In this study, it is the first time that expression of carboxylesterase 2 in five kinds of cell lines (HeLa > C1498 > active T cell > Jurkat > unactive T cell) has been clarified by flow cytometry, Western blotting, and confocal microscopy analysis. The elucidation of CES2 and its variability in a variety of cells will open new ways for drug metabolism and disease prevention. Graphical abstract We reported a new "substrate-mediated light-on" strategy based on an ester bond cleavage reaction. Most of prepared nanomaterials and organic fluorophores possessed short wavelength emissions in the blue or green region which will not be difficult for cellular imaging. In this study, a novel functional molecule (DDPB) was considered as the substrate for CES2 and the optical "off-on" response was realized. DDPB was cell permeable and possessed very low cytotoxicity. Moreover, the identification of CES2 and their subtle changes in five different cells afforded the sequence for carboxylesterase-2 as Hela > C1498 > Active T cell > Jurkat > Unactive T cell. Inhibition studies showed that the hydrolysis of DDPB was effectively suppressed by bis-p-nitrophenyl phosphate and the cellular tracking results firmly supported this point. To our knowledge, the inter-individual variability for the CES2 expressions in five different cell lines has never been reported via the substrate induced optical changes.


Assuntos
Carboxilesterase/análise , Corantes Fluorescentes/química , Benzoatos/química , Benzoatos/efeitos da radiação , Carboxilesterase/antagonistas & inibidores , Carboxilesterase/metabolismo , Linhagem Celular Tumoral , Teoria da Densidade Funcional , Inibidores Enzimáticos/farmacologia , Corantes Fluorescentes/efeitos da radiação , Humanos , Raios Infravermelhos , Microscopia Confocal , Microscopia de Fluorescência , Modelos Químicos , Nitrilas/química , Nitrilas/efeitos da radiação , Nitrofenóis/farmacologia
16.
Biol Blood Marrow Transplant ; 25(8): 1629-1636, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31048087

RESUMO

Immune-mediated neuropathies (IMNs) following hematopoietic stem cell transplantation have been described recently, which, excluding Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy, may present with atypical patterns. This retrospective, nested, case-control study reviewed data from 3858 patients who received haploidentical hematopoietic stem cell transplantation (haplo-HSCT) during the past 10 years at a single center, and 40 patients (1.04%) with IMN following haplo-HSCT were identified. Chronic graft-versus-host disease (cGVHD) (P = .043) and cytomegalovirus (CMV) viremia (P = .035) were recognized as independent risk factors for the development of IMN after haplo-HSCT. There were no significant differences in overall survival (P = .619), disease-free survival (P = .609), nonrelapse mortality (P = .87), or the incidence of relapse (P = .583) between patients with and without IMN after haplo-HSCT. However, patients with post-transplant IMN were at higher risk of developing cGVHD (P = .012) than patients who did not develop IMN. Twenty-four of the 40 patients with IMN (60%) attained neurologic improvement after treatments including vitamins B1 and B12 and/or immunomodulatory agents. However, 19 (47.5%) patients still had persistent motor/sensory deficits despite receiving timely treatment. More studies are needed to help develop standardized diagnostic and therapeutic strategies for patients with post-transplant IMN.


Assuntos
Doença Enxerto-Hospedeiro , Síndrome de Guillain-Barré , Transplante de Células-Tronco Hematopoéticas , Fatores Imunológicos/administração & dosagem , Polirradiculoneuropatia Desmielinizante Inflamatória Crônica , Tiamina/administração & dosagem , Vitamina B 12/administração & dosagem , Adolescente , Adulto , Aloenxertos , Doença Crônica , Intervalo Livre de Doença , Feminino , Doença Enxerto-Hospedeiro/tratamento farmacológico , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/mortalidade , Síndrome de Guillain-Barré/tratamento farmacológico , Síndrome de Guillain-Barré/etiologia , Síndrome de Guillain-Barré/mortalidade , Humanos , Incidência , Masculino , Polirradiculoneuropatia Desmielinizante Inflamatória Crônica/tratamento farmacológico , Polirradiculoneuropatia Desmielinizante Inflamatória Crônica/etiologia , Polirradiculoneuropatia Desmielinizante Inflamatória Crônica/mortalidade , Fatores de Risco , Taxa de Sobrevida
17.
Br J Haematol ; 180(3): 395-411, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29327472

RESUMO

Immune thrombocytopenia (ITP) is an autoimmune disease. Mesenchymal stem cells (MSCs) play important roles in the physiology and homeostasis of the haematopoietic system, including supporting megakaryocytic differentiation from CD34+ haematopoietic progenitor cells. Tumour necrosis factor alpha-induced protein 3 (TNFAIP3, also termed A20) plays a key role in terminating NF-κB signalling. Human genetic studies showed that the polymorphisms of the TNFAIP3 gene may contribute to ITP susceptibility. In this study, we showed a significant decrease in TNFAIP3 and increase in NF-κB/SMAD7 in ITP-MSCs. In co-cultures with CD34+ cells, NF-κB was overexpressed in MSCs from healthy controls (HC-MSCs) after transfection with NFKBIA (IκB)-specific short hairpin (sh)RNAs, resulting in MSC deficiency and a reduction in megakaryocytic differentiation and thrombopoiesis. Knockdown of TNFAIP3 expression using TNFAIP3-specific shRNAs in HC-MSCs affected megakaryocytopoiesis. However, IKBKB knockdown corrected megakaryocytopoiesis inhibition in the ITP-MSCs by decreasing NF-κB expression. Amplified TNFAIP3 expression in ITP-MSCs by TNFAIP3 cDNA can facilitate megakaryocyte differentiation. shRNA-mediated knockdown of SMAD7 expression rescued the impaired MSC function in ITP patients. Therefore, we demonstrate that a pathological reduction in TNFAIP3 levels induced NF-κB/SMAD7 pathway activation, causing a deficiency in MSCs in ITP patients. The ability of ITP-MSCs to support megakaryocytic differentiation and thrombopoiesis of CD34+ cells was impaired.


Assuntos
Células-Tronco Mesenquimais/metabolismo , NF-kappa B/metabolismo , Púrpura Trombocitopênica Idiopática/etiologia , Púrpura Trombocitopênica Idiopática/metabolismo , Transdução de Sinais , Proteínas Smad/metabolismo , Trombopoese , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/metabolismo , Biomarcadores , Medula Óssea/patologia , Estudos de Casos e Controles , Diferenciação Celular , Ensaio de Unidades Formadoras de Colônias , Citocinas/biossíntese , Expressão Gênica , Humanos , Imunofenotipagem , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/patologia , Modelos Biológicos , NF-kappa B/genética , Púrpura Trombocitopênica Idiopática/diagnóstico , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Proteínas Smad/genética , Trombopoese/efeitos dos fármacos , Trombopoese/genética , Fator de Crescimento Transformador beta/metabolismo , Tretinoína/farmacologia , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética
18.
Ann Hematol ; 97(4): 641-654, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29350259

RESUMO

Anti-GPIIb/IIIa-mediated complement activation has been reported to be important in the pathogenesis of immune thrombocytopenia (ITP). However, the role of the complement system and the involved regulatory mechanism remain equivocal. Beta2-glycoprotein I (ß2-GPI), known as the main target for antiphospholipid autoantibodies, has been demonstrated as a complement regulator. Here, we investigated the complement-regulatory role of ß2-GPI in anti-GPIIb/IIIa-mediated ITP. Plasma complement activation and enhanced complement activation capacity (CAC) were found in ITP patients with anti-GPIIb/IIIa antibodies in vivo and in vitro. Diminished plasma levels of ß2-GPI were shown in patients of this group, which was inversely correlated with C5b-9 deposition. C5b-9 generation was inhibited by approximate physiological concentrations of ß2-GPI, in a dose-dependent manner. Inhibition of C3a generation by ß2-GPI and the existence of ß2-GPI/C3 complexes in plasma indicated a regulation on the level of the C3 convertase. Furthermore, ß2-GPI down-regulated the phosphorylation levels of c-Jun N-terminal kinase (JNK) and cleavage of BH3 interacting domain death agonist (Bid) and ultimately harbored platelet lysis. Our findings may provide a novel link between diminished plasma levels of ß2-GPI and enhanced complement activation, indicating ß2-GPI as a potential diagnostic biomarker and therapeutic target in the treatment of anti-GPIIb/IIIa-mediated ITP.


Assuntos
Ativação do Complemento , Regulação para Baixo , Isoanticorpos/metabolismo , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , Púrpura Trombocitopênica Idiopática/metabolismo , beta 2-Glicoproteína I/metabolismo , Adulto , Idoso , Biomarcadores/sangue , Plaquetas/imunologia , Plaquetas/metabolismo , Plaquetas/patologia , China/epidemiologia , Convertases de Complemento C3-C5/metabolismo , Complemento C3a/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/metabolismo , Complexo Glicoproteico GPIb-IX de Plaquetas/antagonistas & inibidores , Complexo Glicoproteico GPIb-IX de Plaquetas/metabolismo , Púrpura Trombocitopênica Idiopática/imunologia , Púrpura Trombocitopênica Idiopática/patologia , Púrpura Trombocitopênica Idiopática/fisiopatologia , Risco , Trombocitopenia/sangue , Trombocitopenia/imunologia , Trombocitopenia/metabolismo , Trombose/epidemiologia , Trombose/etiologia , Adulto Jovem , beta 2-Glicoproteína I/sangue
19.
Eur J Haematol ; 100(2): 171-181, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29114931

RESUMO

OBJECTIVES: To explore the possible risk factors for the occurrence and mortality of thrombotic microangiopathy (TMA) with concomitant acute graft-vs-host disease (aGVHD) and to investigate outcomes and treatments of this disorder after allo-HSCT. METHODS: Fifty cases diagnosed with TMA with concomitant aGVHD and 150 controls were identified from a cohort composed of 3992 patients who underwent allo-HSCT from 2008 to 2016. RESULTS: Grade III-IV aGVHD (P = .000), acute kidney injury (AKI) (P = .033), and hypertension (P = .028) were significant independent risk factors associated with the occurrence of TMA with concomitant aGVHD. A haptoglobin level below normal (P = .013), a maximum volume of diarrhea >2500 mL/d (P = .015), and bloody diarrhea (P = .049) were significant markers for death in both univariate and multivariate analyses. Patients diagnosed with TMA with concomitant aGVHD had a lower overall survival (OS), a higher non-relapse mortality (NRM), but a lower risk of relapse. CONCLUSIONS: Thrombotic microangiopathy with concomitant aGVHD is a significant complication after allo-HSCT, with a worse outcome, including significantly lower OS and higher NRM. There are specific risk factors associated with occurrence and mortality of this complication.


Assuntos
Gastroenteropatias/epidemiologia , Gastroenteropatias/etiologia , Doença Enxerto-Hospedeiro/epidemiologia , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Microangiopatias Trombóticas/epidemiologia , Microangiopatias Trombóticas/etiologia , Doença Aguda , Adolescente , Adulto , Criança , Feminino , Seguimentos , Gastroenteropatias/diagnóstico , Gastroenteropatias/terapia , Doença Enxerto-Hospedeiro/diagnóstico , Doença Enxerto-Hospedeiro/terapia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Fatores de Risco , Microangiopatias Trombóticas/diagnóstico , Microangiopatias Trombóticas/terapia , Condicionamento Pré-Transplante/efeitos adversos , Condicionamento Pré-Transplante/métodos , Transplante Homólogo , Resultado do Tratamento , Adulto Jovem
20.
Photochem Photobiol Sci ; 17(10): 1329-1336, 2018 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-30112558

RESUMO

Carbonaceous materials have long been developed to utilize "nano-spaces" and numerous guest species could be encapsulated. A remarkable fluorescence difference has been observed after newly designed pyropheophorbide-a-appended carbon nanohorns were incorporated in a cellular medium and confocal microscopy was employed for the determination of the intracellular localization. Our study supported the role of carbon nanohorns as carriers of photodynamic therapy (PDT) agents and their heating behavior was discussed. We have developed a theranostic platform based on photosensitizer-conjugated carbon nanostructures and this system has been applied in an animal model. In addition, a negligible toxicity of CNH-Pyro was found in body weight experiments and histopathological examination of the major organs.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA