Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 105
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Langmuir ; 40(3): 1761-1773, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38207108

RESUMO

Wet film leveling can greatly promote film uniformity. However, in the field of metal nanowire, wet film leveling is rarely mentioned. For low-viscosity inks like metal nanowire ink, how to realize wet film leveling is still unclear. Herein, we study the wet film leveling of silver nanowire ink and systematically investigate the relationship between leveling effect and influence factors: (1) there is a uniformity-promotion limit for traditional methods, while wet film leveling can break through this limit and further promote the film uniformity; (2) for wet film leveling, lowering ink's surface tension has no effect, and eliminating surface tension gradient by high-surface-tension leveling agent is the main task; (3) leveling process includes wet film destruction process and ink reflow process; (4) in the destruction process, the leveling-agent solubility and quantity dominate the leveling effect, while the influence of surface tension is little; (5) for solubility and quantity, there is a suitable range to realize optimum leveling effect, and the leveling effect exhibits a contrary relationship with the solubility in a suitable range (2-11%); (6) in the reflow process, the main influence factor is ink viscosity, and the leveling effect exhibits a contrary relationship with ink viscosity. After being leveled by 1.5% n-pentanol, the sheet resistance and sheet-resistance variation coefficient of film decrease from 38.3 Ω/sq/3.83% to 25.7 Ω/sq/1.88%. Further study reveals that the film improvement is not from the ink wettability and drying. Above theoretical results possess certain universality for film preparation by a wet process and can be used by the science and industry field.

2.
Phys Chem Chem Phys ; 25(41): 28510-28516, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37847129

RESUMO

2D transition metal dichalcogenides (TMDs) demonstrate significant promise in logic circuits and optoelectronic devices because of their unique structures and excellent semiconductor properties. However, they inevitably undergo out-of-plane deformation during practical applications due to their ultra-thin structures. Recent experiments have shown that out-of-plane deformation significantly affects the electronic structures of 2D TMDs. However, the underlying physical mechanism is largely unknown. Therefore, it is critical to have a deeper understanding of out-of-plane deformation in 2D TMDs to optimize their applications in different fields. Currently, one of the most pressing matters that requires clarification is the chirality dependence of out-of-plane deformation in tuning the electromechanical properties of 2D TMDs. In this work, using single-layer MoS2 as a probe, we systematically investigate the effects of out-of-plane deformation along different chirality directions on the bond length, bending stiffness, electric polarization, and band structure of 2D TMDs by employing first-principles calculations based on density functional theory. Our results indicate that the bond length, bending energy, polarization strength, and band gap size of single-layer MoS2 are isotropic under out-of-plane deformation, while the band gap type is closely related to the direction of deformation. Our study will provide an essential theoretical basis for further revealing the structure-performance relationship of 2D TMDs.

3.
J Chem Phys ; 158(8): 084702, 2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36859079

RESUMO

Out-of-plane deformation in graphene is unavoidable during both synthesis and transfer procedures due to its special flexibility, which distorts the lattice and eventually imposes crucial effects on the physical features of graphene. Nowadays, however, little is known about this phenomenon, especially for zero-dimensional bulges formed in graphene. In this work, employing first-principles-based theoretical calculations, we systematically studied the bulge effect on the geometric, electronic, and transport properties of graphene. We demonstrate that the bulge formation can introduce mechanical strains (lower than 2%) to the graphene's lattice, which leads to a significant charge redistribution throughout the structure. More interestingly, a visible energy band splitting was observed with the occurrence of zero-dimensional bulges in graphene, which can be attributed to the interlayer coupling that stems from the bulged structure. In addition, it finds that the formed bulges in graphene increase the electron states near the Fermi level, which may account for the enhanced carrier concentration. However, the lowered carrier mobility and growing phonon scattering caused by the formed bulges diminish the transport of both electrons and heat in graphene. Finally, we indicate that bulges arising in graphene increase the possibility of intrinsic defect formation. Our work will evoke attention to the out-of-plane deformation in 2D materials and provide new light to tune their physical properties in the future.

4.
Inorg Chem ; 61(19): 7617-7623, 2022 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-35504044

RESUMO

Eu2+-activated alkali-lithosilicate phosphors exhibit narrow-band emissions that are attractive to high color-rendition and wide color-gamut displays. The microscopic mechanism behind the small emission bandwidth is not presently understood. Here, we report an explicit calculation of the vibronic process occurring in the narrow-band green emission of Rb2Na2[Li3SiO4]4:Eu2+. We show that due to the high rigidity of the host material, the structural strain induced by the localized Eu2+ 4f-5d excitation is distributed among the atoms far beyond the first coordination shell and hence reduces the local structural relaxation around Eu2+. The emission bandshape is thus mainly controlled by the coupling of the electronic transition with the phonon modes associated with motions of host constituent atoms, which was further validated by the good agreement of the calculated bandshape with the experiment. The results provide insights into the generation of narrow-band emission and improve our knowledge on electron-phonon coupling of 4f-5d transitions in phosphors.

5.
Inorg Chem ; 61(13): 5425-5432, 2022 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-35332776

RESUMO

Nowadays, the construction of photothermal therapy (PTT) agents integrated with real-time thermometry for cancer treatment in deep tissues has become a research hotspot. Herein, an excellent photothermal conversion material, BaY2O4: Yb3+/Nd3+, assembled with real-time optical thermometry is developed successfully. Ultrasensitive temperature sensing is implemented through the fluorescence intensity ratio of thermally coupled Nd3+: 4Fj (j = 7/2, 5/2, and 3/2) with a maximal absolute and relative sensitivity of 68.88 and 3.29% K-1, respectively, which surpass the overwhelming majority of the same type of thermometers. Especially, a thermally enhanced Nd3+ luminescence with a factor of 180 is detected with irradiation at 980 nm, resulting from the improvement in phonon-assisted energy transfer efficiency. Meanwhile, the photothermal conversion performance of the sample is excellent enough to destroy the pathological tissues, of which the temperature can be raised to 319.3 K after 180 s of near-infrared (NIR) irradiation with an invariable power density of 13.74 mW/mm2. Besides, the NIR emission of Nd3+ can reach a depth of 7 mm in the biological tissues, as determined by an ex vivo experiment. All the results show the potential application of BaY2O4: Yb3+/Nd3+ as a deep-tissue PTT agent simultaneously equipped with photothermal conversion and temperature sensing function.


Assuntos
Baías , Termômetros , Raios Infravermelhos , Luminescência , Temperatura
6.
J Stroke Cerebrovasc Dis ; 31(7): 106446, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35512466

RESUMO

OBJECTIVES: The aim of the randomized, double-blind, sham-controlled trial was to explore the efficacy and safety of HF-rPMS synchronosly applied to the axilla (stimulating the brachial plexus) and the popliteal fossa (stimulating the tibial nerve and common peroneal nerve) in patients with intracerebral hemorrhage on rehabilitation of motor functions. MATERIALS AND METHODS: Patients with intracerebral haemorrhage in the early period were recruited and randomly assigned to the HF-rPMS group or the sham rPMS group. The two synchrous coils of magnetic stimulation in the two groups were respectively applied to the axilla and the popliteal fossa of the affected limb. But the sham group received the ineffective rPMS and only heard the sound as occured in the HF-rPMS group. Clinical outcomes included the change of Fugl-Meyer Assessment (FMA) scale and Medical Research Council (MRC) scale before and after HF-rPMS. RESULTS: Of 76 eligible patients, 30 were included and only 26 patients completed this study. The diferences on the improvement of the upper extremity FMA (P=0.012), the lower extremity FMA (P=0.001), the proximal MRC of upper extremity (p = 0.043), the proximal MRC of lower extremity (p= 0.004) and the distal MRC scores of lower extremity (p= 0.008) between the the HF-rPMS group and sham rPMS group were statistically signifcant. CONCLUSIONS: Synchrous HF-rPMS intervention at the axilla and the popliteal fossa significantly improved motor function and proximal muscle strength of upper and lower limb of patients in acute or early subacute phase of intracerebral hemorrhage.


Assuntos
Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Hemorragia Cerebral/diagnóstico , Hemorragia Cerebral/terapia , Humanos , Fenômenos Magnéticos , Recuperação de Função Fisiológica/fisiologia , Estimulação Magnética Transcraniana , Resultado do Tratamento , Extremidade Superior
7.
Int J Mol Sci ; 23(19)2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36232942

RESUMO

The pseudocapacitor material is easily decomposed when immersed in alkaline solution for a long time. Hence, it is necessary to find a strategy to improve the alkali stability of pseudocapacitor materials. In addition, the relationship between alkali stability and electrochemical performance is still unclear. In this work, a series of Al-based LDH (Layered double hydroxide) and derived Ni/Co-based sulfides are prepared, and corresponding alkali stability and electrochemical performance are analyzed. The alkali stability of CoAl LDH is so poor and can be improved effectively by doping of Ni. Ni1Co2S4 and Ni2Co1Al LDH exhibit an outstanding alkali stability, and Ni2Co1S4 exhibits an extremely poor alkali stability. The variable valence state of Co element and the solubility of Al in alkali solution are the fundamental reasons for the poor alkali stability of CoAl LDH and Ni2Co1S4. Ni2Co1S4 showed an outstanding electrochemical performance in a three-electrode system, which is better than that of Ni1Co2S4, indicating that there is no direct correlation between alkali stability and electrochemical properties. Sulfidation improved the electrical conductivity and electrochemical activity of electrode materials, whereas alkali etching suppressed the occurrence of the electrochemical reaction. Overall, this work provides a clear perspective to understand the relationship between alkali stability and electrochemical properties.


Assuntos
Álcalis , Hidróxidos , Cobalto/química , Hidróxidos/química , Sulfetos
8.
Opt Express ; 28(22): 33747-33757, 2020 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-33115034

RESUMO

A strategy of optical temperature sensing was developed by using various thermal quenching of Mn4+ and Eu3+ for double perovskite tellurite phosphor in optical thermometers. Herein, SrGdLiTeO6 (SGLT): Mn4+,Eu3+ phosphors were synthesized by a high-temperature solid-state reaction method. The temperature-dependent emission spectra indicated that two distinguishable emission peaks originated from Eu3+ and Mn4+ exhibited significantly diverse temperature responses. Therefore, optical thermometers with a dual-mode mechanism were designed by employing a fluorescence intensity ratio (FIR) of Mn4+ (2Eg→4A2g) and Eu3+ (5D0→7F1,2) and the decay lifetime of Mn4+ as the temperature readouts. The temperature sensing of the phosphors ranging from 300 to 550 K were studied. The maximum relative sensitivities (Sr) are obtained as 4.9% K-1 at 550 K. Meanwhile, the 695 nm emission of Mn4+ possessed a temperature-dependent decay lifetime with Sr of 0.229% K-1 at 573 K. Relevant results demonstrate the SrGdLiTeO6:Mn4+, Eu3+ phosphor as an optical thermometer candidate and also provide constructive suggestions and guidance for constructing high-sensitivity dual-mode optical thermometers.

9.
Opt Lett ; 45(13): 3637-3640, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32630918

RESUMO

Optical thermometry has been developed as a promising temperature-sensing technique. We propose a new, to the best of our knowledge, strategy of fluorescence intensity ratio (FIR), based on an abnormal thermal quenching effect. In the phosphors of Sr3Lu(VO4)3:Eu3+ and CaWO4:Nd3+, the f-f emission intensity of the doped lanthanide ions increases with raising temperature upon the excitation of the charge transfer band (CTB) of the host. The abnormal thermal quenching is caused by the thermally activated absorption, which is proved by temperature-dependent diffuse reflectance spectra. The opposite change tendency of M-O (M=V5+ or W6+) CTB and Ln3+ (Ln=Eu3+ or Nd3+) f-f transitions has been observed in the temperature-dependent excitation spectra and employed as the thermometric probe in ratiometric luminescent thermometry. The strategy applies to the FIR technique in lanthanide singly doped phosphors and eliminates the limitation of thermal-coupled levels. It opens up new possibilities of ratiometric optical thermometry. In addition, the derived maximum relative sensitivity is larger than the value obtained via thermal-coupled levels in the same sample. This illustrates that optical thermometry based on abnormal thermal quenching might be a feasible and effective method.

10.
Inorg Chem ; 59(15): 11054-11060, 2020 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-32677440

RESUMO

In this paper, BaY2O4:Yb3+/Er3+, a high efficient red upconversion (UC) material, is first utilized as an optical thermometer in the biological window, accomplished through the fluorescence intensity ratio (FIR) of thermally coupled Stark sublevels of 4F9/2 (FIR(654/663)). The maximum absolute sensitivity of FIR(654/663)) is 0.19% K-1 at 298 K, which is much higher than most previous reports about FIR-based temperature sensors located in the biological windows. More importantly, the groove of FIR(654/663) for thermometry is nicely located in the physiological temperature range, indicating its potential thermometry application value in biomedicine. Furthermore, a simply ex vivo experiment is implemented to evaluate the penetration depth of the red emission in biological tissues, revealing that a detection depth of 6 mm can be achieved without any effect on the FIR values of I654 to I663. Beyond that, the temperature sensing behaviors of the thermally coupled levels 2H11/2 and 4S3/2 (FIR(523/550)) are also investigated in detail. In the studied temperature range, the absolute sensitivity of FIR(523/550) monotonously increases with the rising temperature and reaches its maximum value 0.31% K-1 at 573 K. All the results imply that BaY2O4:Yb3+/Er3+ is a promising candidate for deep-tissue optical thermometry with high sensitivity.


Assuntos
Luminescência , Temperatura , Termômetros , Animais , Bário/química , Mama , Galinhas , Érbio/química , Oxigênio/química , Itérbio/química , Ítrio/química
11.
Inorg Chem ; 58(6): 3780-3788, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-30810033

RESUMO

A series of lanthanide organic complexes, namely, [Ln2PDC3(H2O)3]H2O (Ln = Eu, Tb, Eu xTb2- x, H2PDC: pyridine-3,5-dicarboxylic acid), were synthesized via hydrothermal method. Eu-PDC was characterized by single-crystal X-ray diffraction. The powder X-ray diffraction, Fourier transform infrared spectra, and thermogravimetric analysis illustrate that Eu-PDC, Tb-PDC, and Eu xTb2- x-PDC complexes are isostructural. All the complexes exhibit strong emission even though water molecules coordinated in the structure. Tunable emission color from green, yellow to red is realized by adjusting the Eu/Tb ratio in mixed Eu xTb2- x-PDC complexes. Energy transfer from Tb3+ to Eu3+ is discussed in detail via fluorescence decay and time resolution spectra. The detailed energy transfer process sees that the emitting color of Eu0.15Tb1.85-PDC shifts from green to orange in a time interval of 153-790 µs. In addition, temperature-dependent emission of the Eu0.05Tb1.95-PDC complex indicates that it is a potential solid state material for a luminescence thermometer in the range of 293-333 K. The temperature resolution is less than 0.16 K. The optical properties of the EuTb-PDC complex indicate that it is a multifunctional luminescent material with promising applications in temperature sensing, time resolution imaging, lighting, and displaying.

12.
Inorg Chem ; 58(12): 8245-8252, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31145602

RESUMO

The optical thermometry properties of LuVO4:Yb3+/Er3+@SiO2 nanoparticles (NPs) are studied in detail. In order to avoid the overheating effect for biological tissue caused by 980 nm radiation, 915 nm is employed as the excitation wavelength to investigate the upconversion (UC) and optical thermometry properties of the as-prepared NPs. In the visible region, the fluorescence intensity ratio (FIR) of the 2H11/2 and 4S3/2 levels of Er3+ is utilized to measure the temperature. The relative sensitivity SR in this case can be written as 1077/ T2, which is higher than that of ß-NaYF4:Yb3+/Er3+ NPs, ß-NaLuF4:Yb3+/Er3+ NPs, YVO4:Yb3+/Er3+ NPs, etc. In the near-infrared (NIR) region, an anomalous enhancement of the 4I13/2 → 4I15/2 transition with increasing temperature is observed. What is more, the FIR of peak 2 (located at 1496 nm) to peak 1 (located at 1527 nm) is changed regularly with increasing temperature, which can also be used to measure the temperature. The combination of the visible and NIR regions for optical thermometry can provide a self-referenced temperature determination to make measurement of the temperature more precise. In addition, the UC mechanism is also investigated, especially the population route of the 4F9/2 level of Er3+. Through analysis of the decay curves, we propose that the dominant way for populating the Er3+ 4F9/2 level is energy transfer from the Yb3+ 2F5/2 level to the Er3+ 4I13/2 level. All of the results reveal the potential application of LuVO4:Yb3+/Er3+@SiO2 NPs for dual-mode optical thermometry.

13.
J Neurochem ; 144(3): 255-270, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29193067

RESUMO

Epilepsy is a chronic brain disease affecting millions of individuals. Kainate receptors, especially kainate-type of ionotropic glutamate receptor 2 (GluK2), play an important role in epileptogenesis. Recent data showed that GluK2 could undergo post-translational modifications in terms of S-nitrosylation (SNO), and affect the signaling pathway of cell death in cerebral ischemia-reperfusion. However, it is unclear whether S-nitrosylation of GluK2 (SNO-GluK2) contributes to cell death induced by epilepsy. Here, we report that kainic acid-induced SNO-GluK2 is mediated by GluK2 itself, regulated by neuronal nitric oxide synthase (nNOS) and the level of cytoplasmic calcium in vivo and in vitro hippocampus neurons. The whole-cell patch clamp recordings showed the influence of SNO-GluK2 on ion channel characterization of GluK2-Kainate receptors. Moreover, immunohistochemistry staining results showed that inhibition of SNO-GluK2 by blocking nNOS or GluK2 or by reducing the level of cytoplasmic calcium-protected hippocampal neurons from kainic acid-induced injury. Finally, immunoprecipitation and western blotting data revealed the involvement of assembly of a GluK2-PSD95-nNOS signaling complex in epilepsy. Taken together, our results showed that the SNO-GluK2 plays an important role in neuronal injury of epileptic rats by forming GluK2-PSD95-nNOS signaling module in a cytoplasmic calcium-dependent way, suggesting a potential therapeutic target site for epilepsy.


Assuntos
Epilepsia/metabolismo , Hipocampo/metabolismo , Ácido Caínico/administração & dosagem , Neurônios/metabolismo , Óxido Nítrico/metabolismo , Receptores de Ácido Caínico/metabolismo , Animais , Cálcio/metabolismo , Proteína 4 Homóloga a Disks-Large/metabolismo , Epilepsia/induzido quimicamente , Hipocampo/efeitos dos fármacos , Masculino , Neurônios/efeitos dos fármacos , Óxido Nítrico Sintase Tipo I/metabolismo , Cultura Primária de Células , Ratos Sprague-Dawley , Transdução de Sinais , Receptor de GluK2 Cainato
14.
Inorg Chem ; 56(22): 13955-13961, 2017 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-29095599

RESUMO

The red upconversion (UC) emission of Eu3+ ions in Lu2O3: Yb3+/Eu3+ powders was successfully enhanced by tridoping Ho3+ ions in the matrix, which is due to the bridging function of Ho3+ ions. The experiment data manifest that, in Yb3+/Eu3+/Ho3+ tridoped system, the Ho3+ ions are first populated to the green emitting level 5F4/5S2 through the energy transfer (ET) processes from the excited Yb3+ ions. Subsequently, the Ho3+ ions at 5F4/5S2 level can transfer their energy to the Eu3+ ions at the ground state, resulting in the population of Eu3+5D0 level. With the assistance of the bridging function of Ho3+ ion, this ET process is more efficient than the cooperative sensitization process between Yb3+ ion and Eu3+ ion. Compared with Lu2O3: 5 mol % Yb3+/1 mol % Eu3+, the UC intensity of Eu3+5D0→7F2 transition in Lu2O3: 5 mol % Yb3+/1 mol % Eu3+/0.5 mol % Ho3+ is increased by a factor of 8.

15.
Inorg Chem ; 56(15): 9194-9199, 2017 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-28699751

RESUMO

The monochromaticity improvement of green upconversion (UC) in Lu2O3:Yb3+/Ho3+ powders has been successfully realized by tridoping Eu3+. The integral area ratio of green emission to red emission of Ho3+ increases 4.3 times with increasing Eu3+ doping concentration from 0 to 20 mol %. The energy transfer (ET) mechanism in the Yb3+/Ho3+/Eu3+ tridoping system has been investigated carefully by visible and near-infrared (NIR) emission spectra along with the decay curves, revealing the existence of ET from the Ho3+5F4/5S2 level tothe Eu3+5D0 level and ET from the Ho3+5I6 level to the Eu3+7F6 level. In addition, the population routes of the red-emitting Ho3+5F5 level in the Yb3+/Ho3+ codoped system under 980 nm wavelength excitation have also been explored. The ET process from the Yb3+2F5/2 level to the Ho3+5I7 level and the cross-relaxation process between two nearby Ho3+ ions in the 5F4/5S2 level and 5I7 level, respectively, have been demonstrated to be the dominant approaches for populating the Ho3+5F5 level. The multiphonon relaxation process originating from the Ho3+5F4/5S2 level is useless to populate the Ho3+5F5 level. As the energy level gap between the Ho3+5I7 level and Ho3+5I8 level matches well with that between Eu3+7F6 level and Eu3+7F0 level, the energy of the Ho3+5I7 level can be easily transferred to the Eu3+7F6 level by an approximate resonant ET process, resulting in a serious decrease in the red UC emission intensity. Since this ET process is more efficient than the ET from the Ho3+5F4/5S2 level to the Eu3+5D0 level as well as the ET from the Ho3+5I6 level to the Eu3+7F6 level, the integral area ratio of green emission to red emission of Ho3+ has been improved significantly.

16.
Inorg Chem ; 56(3): 1498-1503, 2017 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-28098986

RESUMO

A high-temperature solid-state method was used to synthesize the Ho3+- and Yb3+-codoped cubic Lu2O3 powders. The crystal structures of the as-prepared powders were characterized by X-ray diffraction. The energy-transfer (ET) phenomenon between Ho3+ ions and Yb3+ ions was verified by the steady-state spectra including visible and near-infrared (NIR) regions. Beyond that, the decay curves were also measured to certify the existence of the ET process. The downconversion phenomena appeared when the samples were excited by 446 nm wavelength corresponding to the transition of Ho3+: 5I8→5G6/5F1. On the basis of the analysis of the relationship between the initial transfer rate of Ho3+: 5F3 level and the Yb3+ doping concentration, it indicates that the ET from 5F3 state of Ho3+ ions to 2F5/2 state of Yb3+ ions is mainly through a two-step ET process, not the long-accepted cooperative ET process. In addition, a 62% ET efficiency can be achieved in Lu2O3: 1% Ho3+/30% Yb3+. Unlike the common situations in which the NIR photons are all emitted by the acceptors Yb3+, the sensitizers Ho3+ also make contributions to the NIR emission upon 446 nm wavelength excitation. Meanwhile, the 5I5→5I8 transition and 5F4/5S2→5I6 transition of Ho3+ as well as the 2F5/2→2F7/2 transition of Yb3+ match well with the optimal spectral response of crystalline silicon solar cells. The current research indicates that Lu2O3: Ho3+/Yb3+ is a promising material to improve conversion efficiency of crystalline silicon solar cell.

17.
J Stroke Cerebrovasc Dis ; 26(1): 186-191, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27727072

RESUMO

OBJECTIVE: Chronic kidney disease (CKD) is associated with cerebral small vessel disease (cSVD). However, the relationship between serum cystatin C (CysC) level, a highly sensitive marker of impaired kidney function, and cSVD has not been fully understood. This study aimed to investigate the association between serum CysC level and total burden of cSVD on magnetic resonance imaging (MRI) in patients with acute lacunar stroke. MATERIALS AND METHODS: A total of 210 patients with first-ever acute lacunar stroke occurring within 1 week after onset were included in this study. Serum CysC level, decreased estimated glomerular filtration rate (eGFR), and proteinuria were used to evaluate kidney function. The combined effect of the markers of cSVD on MRI, including lacunar, white matter lesions, cerebral microbleeds, and enlarged perivascular spaces, were used to evaluate the comprehensive cSVD burden. RESULTS: There is a positive association between total cSVD burden and hypertension, low eGFR level, and serum CysC level. After adjustments for potential confounders by ordinal logistic regression, elevated levels of CysC as well as impaired eGFR and the presence of proteinuria were correlated with the burden of total cSVD (odds ratio [OR] 2.633, 95% confidence interval [CI] 1.284-5.403; OR 2.442, 95% CI 1.213-4.918; and OR 2.151, 95% CI 1.162-3.983, respectively). CONCLUSIONS: The elevated level of serum CysC is associated with the total burden of cSVD in patients with acute lacunar stroke independent of conventional risk factors.


Assuntos
Doenças de Pequenos Vasos Cerebrais , Cistatina C/sangue , Imageamento por Ressonância Magnética , Acidente Vascular Cerebral Lacunar , Idoso , Idoso de 80 Anos ou mais , Doenças de Pequenos Vasos Cerebrais/sangue , Doenças de Pequenos Vasos Cerebrais/complicações , Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , Feminino , Taxa de Filtração Glomerular/fisiologia , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/psicologia , Masculino , Pessoa de Meia-Idade , Proteinúria/diagnóstico , Proteinúria/etiologia , Estudos Retrospectivos , Estatísticas não Paramétricas , Acidente Vascular Cerebral Lacunar/sangue , Acidente Vascular Cerebral Lacunar/complicações , Acidente Vascular Cerebral Lacunar/diagnóstico por imagem
18.
Soft Matter ; 12(3): 867-75, 2016 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-26549538

RESUMO

Poly(acrylic acid) (PAA) and lanthanide (Ln) ions, such as Ce(3+), Eu(3+), and Tb(3+), were prepared as dispersed complex colloidal particles through three different protocols with rigorous control of the pH value and mixing ratio. The negatively charged PAA-Ln complex particles were layer-by-layer (LbL) assembled with positively charged poly(diallyldimethyl ammonium) (PDDA) to prepare a thin film. The film thickness growth is much quicker than PDDA/PAA film. Due to the incorporation of Ln(3+) ions, the film exhibits fluorescence. During LbL assembly, PDDA-PAA association based on electrostatic force and PAA-Ce association based on coordination are in competition, which leads to the LbL assembly of PDDA and PAA-Ln complex colloidal particles being a complicated dynamic process.

19.
J Stroke Cerebrovasc Dis ; 25(4): 752-60, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26775268

RESUMO

OBJECTIVE: The research aim was to investigate the effects of dl-3-n-butylphthalide (NBP) on the level of circulating endothelial progenitor cells (EPCs) and clinical outcome in patients with acute ischemic stroke (AIS). MATERIALS AND METHODS: A total of 170 patients were included and randomly assigned to NBP group and control group. All patients were administrated a basic antiplatelet and lipid-lowering therapy. Among the patients, 86 received additional NBP administration for 30 days, whereas 84 received only basic therapy (the control). The level of circulating EPCs (marked with CD34(+)/CD133(+)/KDR(+)) was determined by flow cytometry at baseline and days 7, 14, and 30 after therapy. Impairment of neurological function was evaluated by the National Institutes of Health Stroke Scale (NIHSS) on days 7, 14, 30, and 90 after therapy. The association between the increased level of circulating EPCs and improvement of NIHSS score was evaluated by Pearson analysis. The clinical outcome was evaluated by modified Rankin Scale (mRS) on day 90. During the observation period, any adverse events related to drugs were reported. RESULTS: The levels of circulating EPCs on days 14 and 30 were significantly higher in the NBP group than in the control group. In contrast, NIHSS score was notably lower in NBP group on day 14, 30 and day 90. Pearson correlation analysis revealed a significant association between the increased level of EPCs and improvement of NIHSS score. Also, the mRS score in the NBP group was lower on day 90. Importantly, the reported adverse events in the 2 groups were comparable. CONCLUSION: NBP significantly increases the circulating level and improves clinical outcome in patients with AIS.


Assuntos
Benzofuranos/uso terapêutico , Movimento Celular/efeitos dos fármacos , Células Progenitoras Endoteliais/efeitos dos fármacos , Inibidores da Agregação Plaquetária/uso terapêutico , Acidente Vascular Cerebral/tratamento farmacológico , Idoso , Antígenos CD/metabolismo , Isquemia Encefálica/complicações , Imagem de Difusão por Ressonância Magnética , Células Progenitoras Endoteliais/metabolismo , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Índice de Gravidade de Doença , Estatística como Assunto , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/etiologia , Fatores de Tempo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo
20.
Carcinogenesis ; 36(10): 1136-43, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26163879

RESUMO

The growth arrest special 5 (GAS5) is known to be involved in various cancers. However, its expression regulation remains unclear. Polymorphisms in the promoter region of GAS5 may affect its expression and be associated with cancer susceptibility. In this research, we first evaluated the association of a 5-base pair indel polymorphism (rs145204276) in the promoter region of GAS5 with hepatocelluar carcinoma (HCC) susceptibility in Chinese populations. Logistic regression analysis showed that the deletion allele of rs145204276 significantly increased the risk of HCC in two independent case control sets (1034 HCC and 1054 controls). Further genotype-phenotype association analysis revealed that the deletion allele was markedly correlated with higher expression of GAS5 in HCC tissues. The luciferase activity analysis in an in vitro reporter gene system suggested that the deletion allele improved an increased expression of GAS5 in three hepatoma cell lines. Intriguingly, overexpression of GAS5 displayed an anti-apoptosis effect in HCC cell lines, GAS5 knockdown could partially revert this anti-apoptosis effect, suggesting that GAS5 may act as a proto-oncogene in HCC, in contrast with its inhibitory role in other cancers. Further pyrosequencing revealed that the genotypes of rs145204276 were associated with methylation status of GAS5 promoter region. Taken together, our findings provided evidence that rs145204276 may contribute to hepatocarcinogenesis by affecting methylation status of the GAS5 promoter and subsequently its transcriptional activity thus serving as a potential therapy target for HCC.


Assuntos
Carcinoma Hepatocelular/genética , Mutação INDEL , Neoplasias Hepáticas/genética , RNA Longo não Codificante/genética , Adulto , Alelos , Carcinoma Hepatocelular/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Regiões Promotoras Genéticas , Proto-Oncogene Mas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA