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1.
Small ; 17(38): e2102349, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34390180

RESUMO

Sodium-ion batteries (SIBs) have aroused wide concern due to their potential applications in large-scale energy-storage systems. In this work, a hybrid of Fe7 S8 nanoparticles/N-doped carbon nanofibers (Fe7 S8 /N-CNFs) is designed and synthesized via electrospinning. As an anode for SIBs, Fe7 S8 /N-CNFs exhibit a high reversible capacity of 649.9 mAh g-1 at 0.2 A g-1 after 100 cycles, and superior cycling stability for 2000 cycles at 1 A g-1 with only 0.00302% capacity decay per cycle. Such excellent performance originates from: i) Fe7 S8 nanoparticles (average diameter of 17 nm), which shorten the Na+ diffusion distance; ii) the unique 3D N-CNFs, which enhance the conductivity, alleviate the self-agglomeration and large volume change of Fe7 S8 nanoparticles, and offer numerous active sites for Na+ adsorption and paths for electrolyte diffusion. The fascinating structure and superior electrochemical properties of Fe7 S8 /N-CNFs shed light on developing high-performance SIBs anode materials.

2.
Langmuir ; 32(25): 6211-25, 2016 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-27255455

RESUMO

Nanogels (or nanohydrogels) have been extensively investigated as one of the most promising nanoparticulate biomedical platforms owing to their advantageous properties that combine the characteristics of hydrogel systems with nanoparticles. Among them, smart nanogels that have the ability to respond to external stimuli, such as pH, redox, temperature, enzymes, light, magnetic field and so forth, are most attractive in the area of drug delivery. Besides, numerous multifunctionalized nanogels with high sensitivity and specificity were designed for diagnostic applications. In this feature article, we have reviewed and discussed the recent progress of biodegradable nanogels as smart nanocarriers of anticancer drugs and biomedical diagnostic agents for cancer.


Assuntos
Portadores de Fármacos/química , Hidrogéis/química , Nanopartículas/química
3.
Langmuir ; 30(22): 6602-11, 2014 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-24835108

RESUMO

Magnetic yolk-shell MSP@ZrO2 microspheres consisting of a movable magnetic supraparticle (MSP) core and a crystalline ZrO2 shell were synthesized via a two-step controlled "sol-gel" approach for the first time. First, a large amount of the generated hydrolyzate Zr(OH)4 was firmly fixed onto the surface of the cross-linked polymethylacrylic acid matrix via a strong hydrogen-bonding interaction between Zr(OH)4 and the carboxyl groups. Then a calcination process was adopted to convert the Zr(OH)4 into a continuous ZrO2 shell and simultaneously make the ZrO2 shell crystallized. At the same time, the polymer matrix could be selectively removed to form a yolk-shell structure, which has better dispersibility and higher adsorbing efficiency of phosphopeptides than its solid counterpart. The formation mechanism of such yolk-shell microspheres could be reasonably proved by the results of TEM, TGA, VSM, XRD, and FT-IR characterization. By taking advantage of the unique properties, the yolk-shell MSP@ZrO2 exhibited high specificity and great capability in selective enrichment of phosphopeptides, and a total of 33 unique phosphopeptides mapped to 33 different phosphoproteins had been identified from 1 mL of human saliva. This result clearly demonstrated that the yolk-shell MSP@ZrO2 has great performance in purifying and identifying the low-abundant phosphopeptides from real complex biological samples. Moreover, the synthetic method can be used to produce hybrid yolk-shell MSP@ZrO2-TiO2.


Assuntos
Magnetismo , Microesferas , Fosfopeptídeos/química , Fosfopeptídeos/síntese química
4.
Biochem J ; 453(2): 201-8, 2013 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-23651062

RESUMO

GCM1 (glial cell missing 1) is a short-lived transcription factor essential for placental development. The F-box protein, FBW2 (F-box and WD-repeat domain-containing 2), which contains five WD (tryptophan-aspartate) repeats, recognizes GCM1 and mediates its ubiquitination via the SCFFBW2 E3 ligase complex. Although the interaction between GCM1 and FBW2 is facilitated by GCM1 phosphorylation, it is possible that this interaction might be regulated by additional cellular factors. In the present study, we perform tandem-affinity purification coupled with MS analysis identifying RACK1 (receptor for activated C-kinase 1) as an FBW2-interacting protein. RACK1 is a multifaceted scaffold protein containing seven WD repeats. We demonstrate that the WD repeats in both RACK1 and FBW2 are required for the interaction of RACK1 and FBW2. Furthermore, RACK1 competes with GCM1 for FBW2 and thereby prevents GCM1 ubiquitination, which is also supported by the observation that GCM1 is destabilized in RACK1-knockdown BeWo placental cells. Importantly, RACK1 knockdown leads to decreased expression of the GCM1 target gene HTRA4 (high-temperature requirement protein A4), which encodes a serine protease crucial for cell migration and invasion. As a result, migration and invasion activities are down-regulated in RACK1-knockdown BeWo cells. The present study reveals a novel function for RACK1 to regulate GCM1 activity and placental cell migration and invasion.


Assuntos
Proteínas F-Box/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Nucleares/metabolismo , Placenta/metabolismo , Receptores de Superfície Celular/metabolismo , Fatores de Transcrição/metabolismo , Regulação para Cima , Sequência de Bases , Linhagem Celular , Movimento Celular , Primers do DNA , Proteínas de Ligação a DNA , Feminino , Humanos , Placenta/citologia , Gravidez , Reação em Cadeia da Polimerase em Tempo Real , Receptores de Quinase C Ativada , Ubiquitinação
5.
Langmuir ; 29(20): 6147-55, 2013 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-23611465

RESUMO

A new approach for sensitive detection of a specific ssDNA (single-stranded DNA) sequence based on the surface enhanced Raman spectroscopy (SERS) liquid chip is demonstrated. In this method, the probe DNA (targeting to one part of target ssDNA) was attached to the nano-SERS-tags (poly(styrene-co-acrylic acid)/(silver nanoparticles)/silica composite nanospheres), and the capture DNA (targeting to the other part of target ssDNA) was attached to the Fe3O4/poly(acrylic acid) core/shell nanospheres. The nano-SERS-tags with probe DNA were first allowed to undergo hybridization with the target ssDNA in solution to achieve the best efficiency. Subsequently, the magnetic composite nanospheres with capture DNA were added as the capturing substrates of the target ssDNA combined with the nano-SERS-tags. Upon attraction with an external magnet, the nanospheres (including the nano-SERS-tags) were deposited together due to the hybridization, and the deposit sediment was then analyzed by SERS. Quantitative detection of target ssDNA was achieved based on the well-defined linear correlation between the SERS signal intensity and the target ssDNA quantity in the range of 10 nM to 10 pM, and the limit of detection was approximately 10 pM. Multiplexed detection of up to three different ssDNA targets in one sample was demonstrated using three different types of nano-SERS-tags under a single excitation laser. The experimental results indicated that the liquid-phase DNA sequencing method, thus named the SERS liquid chip (SLC) method, holds significant promises for specific detection of trace targets of organisms.


Assuntos
DNA de Cadeia Simples/análise , Imãs/química , Nanosferas/química , Resinas Acrílicas/síntese química , Resinas Acrílicas/química , Tamanho da Partícula , Análise Espectral Raman , Propriedades de Superfície
6.
Langmuir ; 28(6): 3271-8, 2012 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-22288525

RESUMO

An effective method was developed for synthesizing magnetite/polymer colloidal composite microspheres with controllable variations in size and shape of the nanostructures and desirable interfacial chemical functionalities, using surfactant-free seeded emulsion polymerization with magnetite (Fe(3)O(4)) colloidal nanocrystal clusters (CNCs) as the seed, styrene (St) as the monomer, and potassium persulfate (KPS) as the initiator. The sub-micrometer-sized citrate-acid-stabilized Fe(3)O(4) CNCs were first obtained via ethylene glycol (EG)-mediated solvothermal synthesis, followed by 3-(trimethoxysilyl)propyl methacrylate (MPS) modification to immobilize the active vinyl groups onto the surfaces, and then the hydrophobic St monomers were polymerized at the interfaces to form the polymer shells by seeded emulsion radical polymerization. The morphology of the composite microspheres could be controlled from raspberry- and flower-like shapes, to eccentric structures by simply adjusting the feeding weight ratio of the seed to the monomer (Fe(3)O(4)/St) and varying the amount of cross-linker divinyl benzene (DVB). The morphological transition was rationalized by considering the viscosity of monomer-swollen polymer matrix and interfacial tension between the seeds and polymer matrix. Functional groups, such as carboxyl, hydroxyl, and epoxy, can be facilely introduced onto the composite microspheres through copolymerization of St with other functional monomers. The resultant microspheres displayed a high saturation magnetization (46 emu/g), well-defined core-shell nanostructures, and surface chemical functionalities, as well as a sustained colloidal stability, promising for further biomedical applications.


Assuntos
Coloides/química , Óxido Ferroso-Férrico/química , Microesferas , Poliestirenos/química , Metacrilatos/química , Nanoestruturas/química , Compostos de Organossilício/química , Propriedades de Superfície , Compostos de Vinila/química
7.
Langmuir ; 28(28): 10565-72, 2012 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-22712558

RESUMO

An ultrafast, facile, and efficient microwave hydrothermal approach was designed to fabricate magnetic Fe(3)O(4)/phenol-formaldehyde (PF) core-shell microspheres for the first time. The structure of the Fe(3)O(4)/PF core-shell microspheres could be well controlled by the in situ polycondensation of phenol and formaldehyde with magnetic Fe(3)O(4) clusters as the seeds in an aqueous solution without any surfactants. The effect of synthetic parameters, such as the feeding amounts of phenol, the dosages of formaldehyde, the reaction temperatures, and the microwave heating time, on the morphologies and sizes of the Fe(3)O(4)/PF microspheres were investigated in details. The phenol-formaldehyde shell is found to be evenly coated on Fe(3)O(4) clusters within 10 min of the irradiation. The as-prepared microspheres were highly uniform in morphology, and the method was found to allow the shell thickness to be finely controlled in the range of 10-200 nm. The properties of the composite microspheres were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetic analysis (TGA), Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). The as-prepared Fe(3)O(4)/PF microspheres were monodisperse and highly dispersible in water, ethanol, N,N-dimethyformamide, and acetone, a beneficial quality for the further functionalization and applications of the Fe(3)O(4)/PF microspheres.


Assuntos
Formaldeído/química , Micro-Ondas , Fenóis/química , Temperatura , Óxido Ferroso-Férrico/síntese química , Óxido Ferroso-Férrico/química , Fenômenos Magnéticos , Microesferas , Tamanho da Partícula , Propriedades de Superfície
8.
Zhonghua Zhong Liu Za Zhi ; 34(6): 441-5, 2012 Jun.
Artigo em Zh | MEDLINE | ID: mdl-22967446

RESUMO

OBJECTIVE: To study the methylation status of retinoic acid receptor ß2 (RARß2) and p16(INK4α) genes in peripheral blood and tumor tissues and the perioperative dynamic changes of free RARß2 and p16(INK4α) in the peripheral blood, and to investigate the relationship between RARß2 and p16(INK4α) methylation in peripheral blood and clinicopathological characteristics of esophageal squamous cell carcinoma (ESCC) and their value in evaluating the completeness of surgical resection. METHODS: Real-time methylation specific polymerase chain reaction (real-time MSP) technique was used to detect the methylation status of RARß2 and p16(INK4α) in tumor tissue, adjacent normal tissue and peripheral blood perioperatively in 76 cases of ESCC. Sixty age-matched healthy volunteers were randomly selected as a control. RESULTS: RARß2 and p16(INK4α) hypermethylation presented in both tumor tissue [72.4% (55/76) and 86.8% (66/76)] and peripheral blood [63.2% (48/76) and 71.1% (54/76)] in the ESCC patients, showing a good agreement between them. RARß2 and p16(INK4α) hypermethylation was significantly related with pathological stage, lymph node metastasis, and invasion of nerves and vessels (P < 0.05). The DNA methylation rate in peripheral blood was increasing first and then decreasing in the preoperative, intraoperative and postoperative periods. Moreover, the RARß2 methylation in peripheral blood was shown to be significantly associated with family history of cancer (P = 0.023). CONCLUSION: RARß2 and p16(INK4α) methylation in the peripheral blood in ESCC patients may reflect the tumor-bearing status in the body, and may serve as a valuable marker in assessment of the degree of completeness of surgical resection in ESCC patients.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Metilação de DNA , Neoplasias Esofágicas/metabolismo , Receptores do Ácido Retinoico/metabolismo , Adulto , Idoso , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/sangue , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/cirurgia , Inibidor p16 de Quinase Dependente de Ciclina/sangue , Inibidor p16 de Quinase Dependente de Ciclina/genética , Neoplasias Esofágicas/sangue , Neoplasias Esofágicas/patologia , Neoplasias Esofágicas/cirurgia , Feminino , Genes p16 , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Receptores do Ácido Retinoico/sangue , Receptores do Ácido Retinoico/genética
9.
Opt Express ; 19(27): 26000-5, 2011 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-22274188

RESUMO

Different sized/shaped micro protrusive lens arrays atop poly(methyl methacrylate) can be fabricated by a simple two-step method, i.e., indentation followed by immersion in ethanol. Profile and projection of obtained microlenses were characterized. Thermal stability of microlenses was examined at 25°C and 60°C. This work demonstrates a cost effective approach for massive fabrication of microlens array with high reliability.


Assuntos
Lentes , Polimetil Metacrilato/química , Desenho de Equipamento , Análise de Falha de Equipamento , Miniaturização
10.
Langmuir ; 27(23): 14539-44, 2011 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-22011076

RESUMO

A systematic study for the preparation of Ag nanoparticle (Ag-NP) coated poly(styrene-co-acrylic acid) (PSA) composite nanospheres by in situ chemical reduction is reported. The experimental results showed that the reaction temperature and the surface coverage of the -COOH determined the surface coverage and grain size of Ag nanoparticles on the PSA nanospheres. The surface enhanced Raman spectroscopy (SERS) sensitivity was investigated using 4-hydroxythiophenol (4-HBT) as the model probe in the solution of composite nanospheres stabilized by polyvinylpyrrolidone (PSA/Ag-NPs/PVP), with the detection limit of about 1 × 10(-6) M. Potential application of the new SERS substrate was demonstrated with the detection of melamine, and the detection limit was about 1 × 10(-3) M. Chemical noises from PVP and other impurities were observed and attributed mainly to the competitive adsorption of PVP on the surfaces of Ag-NPs. After tetrahydrofuran washing of the PSA/Ag-NPs/PVP substrates that removed the PVP and other residuals, the signal/noise levels of SERS were greatly improved and the detection limit of melamine was determined to be 1 × 10(-7) M. This result indicated that the new PSA/Ag-NPs system is highly effective and can be used as the SERS-active substrate for trace analysis of a variety of drugs and food additives.


Assuntos
Acrilatos/química , Nanopartículas Metálicas/química , Poliestirenos/química , Prata/química , Triazinas/análise , Tamanho da Partícula , Soluções , Análise Espectral Raman , Propriedades de Superfície
11.
Langmuir ; 26(3): 1674-9, 2010 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-19754089

RESUMO

Monodisperse organic/inorganic composite microspheres with well-defined structure were prepared through the encapsulation of silica coated superparamagnetic magnetite colloidal nanoparticle clusters (CNCs) with cross-linked poly(N-isopropylacrylamide) (PNIPAM) shell. At first, the sub-micrometer-sized CNCs were fabricated by the solvothermal process, and then a silica layer was coated on the surface of CNCs through a sol-gel process, and finally, a thermoresponsive shell of PNIPAM was deposited onto the surface of the core/shell magnetic microspheres by a precipitation polymerization. The experimental results showed that the size of Fe(3)O(4) core, the thickness of SiO(2) shell, as well as volume phase transition temperature (VPTT) of PNIPAM shell could be well controlled, and this structured modulation could satisfy different requirements. The superparamagnetic behavior, high magnetization (the saturation magnetization of Fe(3)O(4)/SiO(2)/PNIPAM microspheres with a 10% cross-linking density is 41.6 emu/g), and good thermosensitivity make these composite microspheres an ideal candidate for various important applications such as in controlled drug delivery, bioseparation, and catalysis.

12.
ACS Nano ; 14(12): 16565-16575, 2020 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-33025785

RESUMO

Modern development of flexible electronics has made use of bioelectronic materials as artificial tissue in vivo. As hydrogels are more similar to nerve tissue, functional hydrogels have become a promising candidate for bioelectronics. Meanwhile, interfacing functional hydrogels and living tissues is at the forefront of bioelectronics. The peripheral nerve injury often leads to paralysis, chronic pain, neurologic disorders, and even disability, because it has affected the bioelectrical signal transmission between the brain and the rest of body. Here, a kind of light-stimuli-responsive and stretchable conducting polymer hydrogel (CPH) is developed to explore artificial nerve. The conductivity of CPH can be enhanced when illuminated by near-infrared light, which can promote the conduction of the bioelectrical signal. When CPH is mechanically elongated, it still has high durability of conductivity and, thus, can accommodate unexpected strain of nerve tissues in motion. Thereby, CPH can better serve as an implant of the serious peripheral nerve injury in vivo, especially in the case that the length of the missing nerve exceeds 10 mm.

13.
Small ; 5(5): 621-8, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19189322

RESUMO

A new approach to the fabrication of magnetic thermosensitive microcontainers of Fe(3)O(4) nanoparticles with poly(N-isopropylacrylamide) walls is presented. The microcontainers undergo a temperature-induced volume phase transition and present an impressive magnetic response. The microcontainers have a well-defined structure with a narrow size distribution. The wall thicknesses of the microcontainers can be controlled according to requirements. Compared to other preparation methods, the process is simple and reproducible. The magnetic saturation of these microcontainers is high enough to meet most requirements of bioapplications. To further investigate the potential application of these microcontainers, they are tested as drug carriers, with the drug loading and releasing processes carefully studied. The drug encapsulation efficiency and drug content in the carriers are pH-dependent, and the carriers have a maximal drug loading of about 50 wt% under alkaline conditions. The release of the drug from the microcontainers can be controlled by the environmental pH, temperature, and magnetic force.


Assuntos
Resinas Acrílicas/química , Doxorrubicina/administração & dosagem , Doxorrubicina/química , Portadores de Fármacos/química , Portadores de Fármacos/efeitos da radiação , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Difusão , Campos Eletromagnéticos , Teste de Materiais , Nanomedicina/métodos , Tamanho da Partícula , Temperatura
14.
J Fluoresc ; 19(4): 615-21, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19104920

RESUMO

To effectively image living cells with quantum dots (QDs), particularly for those cells containing high content of native fluorophores, the two-photon excitation (TPE) with a femto-second 800 nm laser was employed and compared with the single-photon excitations (SPE) of 405 nm and 488 nm in BY-2 Tobacco (BY-2-T) and human hepatocellular carcinoma (QGY) cells, respectively. The 405 nm SPE produced the bright photoluminescence (PL) signals of cellular QDs but also induced a strong autofluorescence(AF) from the native fluorophores like flavins in cells. The AF occupied about 30% and 13% of the total signals detected in QD imaging channel in the BY-2-T and QGY cells, respectively. With the excitation of 488 nm SPE, the PL signals were lower than those excited with the 405 nm SPE, although the AF signals were also reduced. The 800 nm TPE generated the best PL images of intracellular QDs with the highest signal ratio of PL to AF, because the two-photon absorption cross section of QDs is much higher than that of the native fluorophores. By means of the TPE, the reliable cellular imaging with QDs, even for the cells having the high AF background, can be achieved.


Assuntos
Compostos de Cádmio/química , Carcinoma Hepatocelular/patologia , Fluorescência , Neoplasias Hepáticas/patologia , Nicotiana/citologia , Fótons , Pontos Quânticos , Compostos de Sulfidrila/química , Telúrio/química , Compostos de Cádmio/síntese química , Linhagem Celular Tumoral , Sobrevivência Celular , Humanos
15.
Zhen Ci Yan Jiu ; 43(6): 375-9, 2018 Jun 25.
Artigo em Zh | MEDLINE | ID: mdl-30091544

RESUMO

OBJECTIVE: To observe the effect of liver-soothing and mental-activity-regulating (LSMAR) needling on behavior reactions and contents of serum calcitonin gene-related peptide (CGRP), substance P (SP), interleukin-1 ß (IL-1 ß) and tumor necrosis factor-α (TNF-α) in migraine rats, so as to explore its mechanism underlying relief of migraine. METHODS: Thirty-two male Wistar rats were randomly divided into control, model, LSMAR needling and conventional needling groups (n=8 rats in each). The migraine model was established by hypodermic injection of glyceryl trinitrate (5 mg/kg) at the napex. Acupuncture preconditioning was conducted once daily for 8 days before modeling. Acupuncture needles were inserted into "Baihui" (GV 20), and bilateral "Fengchi" (GB 20), "Neiguan" (PC 6) and "Taichong" (LR 3), manipulated for a while and retained for 30 min. The rats' behavioral changes (times of head scratching, tail-biting, cage-crawling, and to- and fro-movement in 30 min) were scored (one symptom = one point) before modeling, after modeling, and after intervention. The concentrations of CGRP, SP, IL-1 ß, TNF-α in serum were assayed by enzyme-linked immunosorbent assay (ELISA). RESULTS: After modeling, the behavioral scores were significantly increased in the migraine model rats relevant to the control group (P<0.05). Whereas after the treatment, the behavior scores were considerably decreased during 60-90 min and 120-150 min of the measuring period in both LSMAR and conventional needling groups compared with the model group (P<0.05). The concentrations of CGRP, SP, IL-1 ß and TNF-α were significantly higher in the model group than in the control group (P<0.05), and notably lower in both LSMAR and conventional needling groups than in the model group (P<0.05). The therapeutic effect of LSMAR was markedly superior to that of conventional needling in down-regulating the concentrations of CGRP, SP, IL-1 ß and TNF-α (P<0.05). CONCLUSION: Acupuncture preconditioning can effectively relieve pain in migraine rats possibly by decreasing the concentrations of CGRP, SP, IL-1 ß and TNF-α in the peripheral blood, and the therapeutic effect of LSMAR is evidently superior to that of conventional needling.


Assuntos
Terapia por Acupuntura , Transtornos de Enxaqueca , Animais , Calcitonina , Peptídeo Relacionado com Gene de Calcitonina , Interleucina-1beta , Masculino , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Substância P , Fator de Necrose Tumoral alfa
16.
Zhen Ci Yan Jiu ; 43(7): 440-4, 2018 Jul 25.
Artigo em Zh | MEDLINE | ID: mdl-30094981

RESUMO

OBJECTIVE: To observe the effect of liver-soothing and mental-activity-regulating (LSMAR) needling on the expression of receptor activity-modifying protein 1 (RAMP 1, receptor of calcitonin gene-related peptide), 5-hydroxytryptamine 1 D receptor(5-HT 1 DR) in the spinal trigeminal nucleus (STN) and midbrain in migraine rats, so as to explore its underlying mechanism in relieving migraine. METHODS: A total of 40 male Wistar rats were randomly divided into control, model, LSMAR and conventional needling groups (n=10 rats in each). The migraine model was established by subcutaneous injection of nitroglycerin at the posterior neck. LSMAR was applied to "Baihui" (GV 20), bilateral "Fengchi" (GB 20), "Neiguan" (PC 6) and "Taichong" (LR 3) in the LSMAR group and conventional needling was applied to "Baihui" (GV 20) and bilateral "Fengchi" (GB 20) in the conventional acupuncture group for 30 min, once a day for 8 days before modeling. The expression levels of RAMP 1 and 5-HT 1 DR proteins and mRNAs in the STN and mesencephalon were detected by real-time fluorescent quantitative PCR and Western blot, separately. RESULTS: Compared with the control group, the expression levels of RAMP 1 protein and mRNA in STN and mesencephalon were significantly increased (P<0.05) and those of 5-HT 1 DR protein and mRNA considerably decreased (P<0.05) in the model group. After the acupuncture treatment, the increased levels of RAMP 1 protein and mRNA and the decreased levels of 5-HT 1 DR protein and mRNA in the STN and midbrain were obviously reversed in the LSMAR and conventional needling groups relevant to the model group (P<0.05). The effect of LSMAR needling was significantly superior to that of conventional needling in down-regulating the expression levels of RAMP 1 mRNA and protein in the STN and mesencephalon (P<0.05) and in up-regulating the expression levels of 5-HT 1 DR mRNA and protein in the two brain regions (P<0.05). CONCLUSION: Manual acupuncture stimulation of GV 20, GB 20, etc. can inhibit the expression of RAMP 1 protein and mRNA in the STN and midbrain, and up-regulate the expression of 5-HT 1 DR in the two brain regions of migraine rats, which may be related to its effect in relieving migraine.


Assuntos
Terapia por Acupuntura , Transtornos de Enxaqueca , Pontos de Acupuntura , Animais , Masculino , Transtornos de Enxaqueca/terapia , Ratos , Ratos Wistar , Proteína 1 Modificadora da Atividade de Receptores , Serotonina
17.
J Phys Chem B ; 111(41): 12012-6, 2007 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-17887665

RESUMO

The process and mechanism of photochemical instability of thiol-capped CdTe quantum dots (QDs) in aqueous solution were experimentally studied. After laser irradiation, the corresponding Raman bands of the Cd-S bond decreased obviously, indicating bond breaking and thiol detachment from the QD surfaces. Meanwhile, a photoinduced aggregation of QDs occurred with the hydrodynamic diameter increased to hundreds of nanometers from an initial 20 nm, as detected with dynamic light scattering measurements. The bleaching of the photoluminescence of QDs under laser irradiation could be attributed to the enhanced nonradiative transfer in excited QDs caused by increased surface defects due to the losing of thiol ligands. Singlet oxygen (1O2) was involved in the photooxidation of QDs, as revealed by the inhibiting effects of 1O2 quenchers of histidine or sodium azide (NaN3) on the photobleaching of QDs. The linear relationship in Stern-Volmer measurements between the terminal product and the concentration of NaN3 demonstrated that 1O2 was the main pathway of the photobleaching in QD solutions. By comparing the photostability of QDs in C2C12 cells with and without NaN3 treatment, the photooxidation effect of 1O2 on photobleaching of cellular QDs was confirmed.


Assuntos
Compostos de Cádmio/química , Pontos Quânticos , Compostos de Sulfidrila/química , Telúrio/química , Animais , Linhagem Celular , Sobrevivência Celular , Cromatografia em Gel , Camundongos , Fotodegradação , Soluções , Análise Espectral Raman
18.
Zhonghua Wai Ke Za Zhi ; 45(10): 705-7, 2007 May 15.
Artigo em Zh | MEDLINE | ID: mdl-17688827

RESUMO

OBJECTIVE: To discuss the possibility of microneurosurgery techniques in the treatment of multisegmental intramedullary cervical spinal cord ependymomas. METHODS: The clinical data of 26 cases of multisegmental intramedullary cervical spinal cord ependymomas patients was reviewed and analyzed. RESULTS: There were 14 cases of cervical spinal cord ependymomas, 12 cases of cervical and thoracic spinal cord ependymomas. 4.5 spinal cord segments were involved in average. Incompletely inferior paraplegia was in 18 cases, incompletely high paraplegia in 8 cases, dyspnea in 6 cases, sphincter dysfunction in 10 cases. MRI detected syringomyelia formation in 24 cases. Vertebral lamina reposition were done in 20 cases. Muscle strength recovered in 21 cases, no change in 4 cases, aggravated in 1 case. All cases had total resection and 1 cases vertebral had instability in MRI. CONCLUSIONS: Total resection of intramedullary cervical spinal cord ependymomas can be achieved by microneurosurgery. Most of the symptoms can be released after microsurgical treatment. After multisegmental laminotomy, the vertebral plate reposition should be done to ensure the stability.


Assuntos
Ependimoma/cirurgia , Neoplasias da Medula Espinal/cirurgia , Adulto , Idoso , Vértebras Cervicais , Feminino , Seguimentos , Humanos , Masculino , Microcirurgia/métodos , Pessoa de Meia-Idade , Procedimentos Neurocirúrgicos/métodos , Estudos Retrospectivos , Resultado do Tratamento
19.
Zhonghua Wai Ke Za Zhi ; 42(13): 787-91, 2004 Jul 07.
Artigo em Zh | MEDLINE | ID: mdl-15363296

RESUMO

OBJECTIVE: To evaluate the validity of intraoperative magnetic MEP (motor evoked potentials) monitoring in a spinal-cord-menaced surgery. METHODS: 32 rabbits were employed in weight-drop spinal cord contusion model. After anesthetized with a combination of Ketamine and Droperidol the spinal cords were surgically exposed with the dura intact, and the contusion injuries were delivered except the rabbits in control group. The MEPs were recorded and the relationship between the variation of the MEPs and the residual locomotor capacity after spinal cord injury was analyzed. RESULTS: The 6 rabbits in mild-spinal-cord-injury group experienced transient attenuation of their TMS-MEPs, and the locomotor capacity remained intact (scores of 5) in almost all rabbits (5 of 6) when assessed 24 hours later; In the moderate-spinal-cord-injury group the 8 rabbits lost their TMS-MEP immediately after the weight-drop contusion, but they regained them partly in 1 hour one after another and scored 4 or 5 in the assessment of muscle power next day except for one score of 2; 8 rabbits had their spinal cords impaired severely in the contusion procedure and lost their TMS-MEP too but without recovery, their locomotor capacity outcomes were very poor, 5 of them had no response to transcranial magnetic stimulation next day, and in the other 3 rabbits we only found some polyphase waves with variant latency and lower amplitude which did not resemble common compound muscle action potential (CMAPs) evoked by TMS. CONCLUSIONS: Myogenic TMS-MEPs was very sensitive to the spinal cord injury and should be a valid technique for intraoperative monitoring, and a slight change of them, even if a transient lose, should be unnecessarily related to a severe movement disorder. The warning threshold for a given patient should depend on the malady itself.


Assuntos
Encéfalo/fisiopatologia , Potencial Evocado Motor/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Estimulação Magnética Transcraniana , Doença Aguda , Animais , Modelos Animais de Doenças , Feminino , Masculino , Monitorização Fisiológica , Prognóstico , Coelhos
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