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2.
Biosens Bioelectron ; 241: 115648, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37690354

RESUMO

Doping sorted graphene quantum dots (GQDs) with heteroatoms and functionalizing them with amino acid could improve their radiative recombination and two-photon properties-including their excitation-wavelength-independent photoluminescence from the ultraviolet to the near-infrared-I (NIR-I) region, absorption, quantum yield, absolute cross section, lifetime, and radiative-to-nonradiative decay ratio-under two-photon excitation (TPE) at a low excitation energy and short photoexcitation duration, as determined using a self-made optical microscopy system with a femtosecond Ti-sapphire laser. Four types of sorted GQDs were investigated: undoped GQDs, nitrogen-doped GQDs (N-GQDs), amino-functionalized GQDs (amino-GQDs), and N-doped and amino-functionalized GQDs (amino-N-GQDs). Among them, the sorted amino-N-GQDs are effective as a two-photon photosensitizer and generate the highest quantity of reactive oxygen species for the elimination of multidrug-resistant cancer cells through two-photon photodynamic therapy (PDT). Larger amino-N-GQDs result in a greater number of C-N and N-functionalities, leading to a superior photochemical effect and more favorable intrinsic luminescence properties, making the dots effective contrast agents for tracking and localizing cancer cells during in-depth bioimaging in a three-dimensional biological environment under TPE in the NIR-II region. Overall, this study highlights the potential of large amino-N-GQDs as a material for future application to dual-modality two-photon PDT and biomedical imaging.


Assuntos
Técnicas Biossensoriais , Grafite , Fotoquimioterapia , Pontos Quânticos , Grafite/química , Iluminação , Resistência a Múltiplos Medicamentos , Pontos Quânticos/química , Resistencia a Medicamentos Antineoplásicos , Fotoquimioterapia/métodos
3.
Int J Mol Sci ; 23(6)2022 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35328653

RESUMO

Nitrogen doping and amino group functionalization through chemical modification lead to strong electron donation. Applying these processes to a large π-conjugated system of graphene quantum dot (GQD)-based materials as electron donors increases the charge transfer efficiency of nitrogen-doped amino acid-functionalized GQDs (amino-N-GQDs), resulting in enhanced two-photon absorption, post-two-photon excitation (TPE) stability, TPE cross-sections, and two-photon luminescence through the radiative pathway when the lifetime decreases and the quantum yield increases. Additionally, it leads to the generation of reactive oxygen species through two-photon photodynamic therapy (PDT). The sorted amino-N-GQDs prepared in this study exhibited excitation-wavelength-independent two-photon luminescence in the near-infrared region through TPE in the near-infrared-II region. The increase in size resulted in size-dependent photochemical and electrochemical efficacy, increased photoluminescence quantum yield, and efficient two-photon PDT. Therefore, the sorted amino-N-GQDs can be applicable as two-photon contrast probes to track and localize analytes in in-depth two-photon imaging executed in a biological environment along with two-photon PDT to eliminate infectious or multidrug-resistant microbes.


Assuntos
Anti-Infecciosos , Grafite , Pontos Quânticos , Antibacterianos , Grafite/farmacologia , Nitrogênio , Fótons
4.
Int J Mol Sci ; 22(18)2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34575859

RESUMO

There is an urgent need for materials that can efficiently generate reactive oxygen species (ROS) and be used in photodynamic therapy (PDT) as two-photon imaging contrast probes. In this study, graphene quantum dots (GQDs) were subjected to amino group functionalization and nitrogen doping (amino-N-GQDs) via annealing and hydrothermal ammonia autoclave treatments. The synthesized dots could serve as a photosensitizer in PDT and generate more ROS than conventional GQDs under 60-s low-energy (fixed output power: 0.07 W·cm-2) excitation exerted by a 670-nm continuous-wave laser. The generated ROS were used to completely eliminate a multidrug-resistant strain of methicillin-resistant Staphylococcus aureus (MRSA), a Gram-positive bacterium. Compared with conventional GQDs, the amino-N-GQDs had superior optical properties, including stronger absorption, higher quantum yield (0.34), stronger luminescence, and high stability under exposure. The high photostability and intrinsic luminescence of amino-N-GQDs contribute to their suitability as contrast probes for use in biomedical imaging, in addition to their bacteria tracking and localization abilities. Herein, the dual-modality amino-N-GQDs in PDT easily eliminated multidrug-resistant bacteria, ultimately revealing their potential for use in future clinical applications.


Assuntos
Antibacterianos/administração & dosagem , Meios de Contraste/química , Portadores de Fármacos/química , Grafite/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Nitrogênio/química , Pontos Quânticos/química , Antioxidantes/administração & dosagem , Testes de Sensibilidade Microbiana , Pontos Quânticos/ultraestrutura
5.
ACS Nano ; 14(9): 11502-11509, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32790323

RESUMO

In this study, sorted nitrogen-doped graphene quantum dots were prepared and subsequently conjugated with polymers. The synthesized materials exhibited excitation-wavelength-independent photoluminescence emissions ranging from ultraviolet to near-infrared and were 0.9-8.4 nm in size. The materials also exhibited high-photoluminescence quantum yields and excellent two-photon properties. Therefore, in two-photon bioimaging the materials with different emission spectra can be effective two-photon contrast agents. Specific antibodies were used to label organelles in cancer cells and identify nuclear antigens, thereby enabling the simultaneous detection of four targets in cells at a single two-photon excitation wavelength. The sorted nitrogen-doped graphene quantum dot materials were determined to be considerably more advantageous than organic dyes in identifying multiplexed targets, and they can be effective probes in cellular imaging.


Assuntos
Grafite , Pontos Quânticos , Nitrogênio , Fótons , Polímeros
6.
Medicine (Baltimore) ; 97(20): e10709, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29768338

RESUMO

RATIONALE: Pantothenate kinase-associated neurodegeneration (PKAN) is a rare autosomal recessive disease. Progressive motor symptoms such as dystonia and spasticity begin in childhood and relentlessly become incapacitating later in life. Treatments including anticholinergics and iron chelation are usually ineffective. Botulinum toxin type A (BoNT-A) is effective for adult patients with dystonia or spasticity. PATIENT CONCERNS: We reported a 10-year-old female patient with advanced PKAN, manifesting as generalized dystonia and spasticity. DIAGNOSIS: The patient was diagnosed with PKAN by a pediatric neurologist. INTERVENTIONS: The patient received BoNT-A injection. OUTCOMES: The effect was obvious at four weeks after the injection, with an improvement of 25% in Barry-Albright Dystonia Scale and 4% in Functional Independence Measure for Children score. Furthermore, there was a 3.8% reduction in Parenting Stress Index Short Form score and 8.3% improvement in Pain and Impact of Disability domain in the score of Cerebral Palsy Quality of Life for Children. LESSONS: BoNT-A injection was effective to improve functional independence and to alleviate stress of caregivers in the patient with advanced PKAN.


Assuntos
Toxinas Botulínicas Tipo A/administração & dosagem , Fármacos Neuromusculares/administração & dosagem , Neurodegeneração Associada a Pantotenato-Quinase/tratamento farmacológico , Poder Familiar/psicologia , Criança , Distonia/tratamento farmacológico , Distonia/etiologia , Feminino , Humanos , Espasticidade Muscular/tratamento farmacológico , Espasticidade Muscular/etiologia , Neurodegeneração Associada a Pantotenato-Quinase/complicações , Neurodegeneração Associada a Pantotenato-Quinase/psicologia , Qualidade de Vida/psicologia , Estresse Psicológico/etiologia , Resultado do Tratamento
7.
Neuropsychiatr Dis Treat ; 13: 981-985, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28408832

RESUMO

INTRODUCTION: Punding is a complex stereotyped behavior, characterized by excessiveness, non-goal orientation, and repetitiveness. It is mostly associated with Parkinson's disease, and very few cases in non-Parkinson's disease have been reported. We report a case of punding associated with supratentorial ischemic stroke. CASE PRESENTATION: We present a 70-year-old man with left posterior cerebral artery infarction with quetiapine-induced punding manifesting as repetitive unidirectional body turning. Remission of punding behavior ensued after cessation of quetiapine and administration of clonazepam. CONCLUSION: This case describes the clinical course of quetiapine-induced punding in a patient with left posterior cerebral artery infarction. It suggests clonazepam may serve as a treatment option for poststroke punding.

8.
Opt Express ; 19(17): 15750-9, 2011 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-21934937

RESUMO

We provide a novel achromatic design in the illumination system for a mini projector with an LED light source. The lateral color aberration at the corners of the DMD active area can be reduced to 0.48 µm by our compact ATIR prism. The total prism size is 4091 mm(3). The spot sizes at the corner and the edge are also controlled under 198 µm. Moreover, we use a light pipe for color uniformity at the center of the DMD active area. Under the two components for color uniformity, the Δu' v' is well controlled under 0.016 by a 20 mm length of light pipe. The illuminance uniformity at the active area of the DMD chip is higher than 92.8%. The optical efficiency of the light pipe is 94.1%.

10.
Arthritis Res Ther ; 6(1): R7-R14, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-14979933

RESUMO

Endogenous opioid peptides have an essential role in the intrinsic modulation and control of inflammatory pain, which could be therapeutically useful. In this study, we established a muscular electroporation method for the gene transfer of pro-opiomelanocortin (POMC) in vivo and investigated its effect on inflammatory pain in a rat model of rheumatoid arthritis. The gene encoding human POMC was inserted into a modified pCMV plasmid, and 0-200 microg of the plasmid-POMC DNA construct was transferred into the tibialis anterior muscle of rats treated with complete Freund's adjuvant (CFA) with or without POMC gene transfer by the electroporation method. The safety and efficiency of the gene transfer was assessed with the following parameters: thermal hyperalgesia, serum adrenocorticotropic hormone (ACTH) and endorphin levels, paw swelling and muscle endorphin levels at 1, 2 and 3 weeks after electroporation. Serum ACTH and endorphin levels of the group into which the gene encoding POMC had been transferred were increased to about 13-14-fold those of the normal control. These levels peaked 1 week after electroporation and significantly decreased 2 weeks after electroporation. Rats that had received the gene encoding POMC had less thermal hypersensitivity and paw swelling than the non-gene-transferred group at days 3, 5 and 7 after injection with CFA. Our promising results showed that transfer of the gene encoding POMC by electroporation is a new and effective method for its expression in vivo, and the analgesic effects of POMC cDNA with electroporation in a rat model of rheumatoid arthritis are reversed by naloxone.

11.
J Clin Anesth ; 15(3): 189-93, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12770654

RESUMO

STUDY OBJECTIVES: To examine the serial time course of perioperative plasma ionized magnesium (iMg(2+)) concentrations and to analyze the plasma iMg(2+) concentrations in children with different body mass who were undergoing open-heart surgery. DESIGN: Randomized, single-blinded study. SETTING: University-affiliated hospital of an academic medical institution. PATIENTS: 38 children undergoing open-heart surgery. INTERVENTIONS: Patients were divided into three groups according to their body mass: Group 1 (n = 12) <10 kg, Group 2 (n = 13) 10 kg to 20 kg, and Group 3 (n = 13) >20 kg. MEASUREMENTS: The relationship of iMg(2+) among the three groups of different body mass were analyzed at five different time intervals during the operation: induction of anesthesia, 5 minutes and 30 minutes after the onset of cardiopulmonary bypass (CPB), the beginning of rewarming, and the end of surgery. MAIN RESULTS: iMg(2+) levels at 5 minutes after onset of CPB in patients weighing less than 20 kg (Groups 1 and 2) differed with those weighing more than 20 kg (Group 3) (p = 0.007 and 0.013). However, there was no difference in the iMg(2+) levels between Groups 1 and 2 (p = 0.993). In addition, iMg(2+) levels at 5 minutes after onset of bypass correlated well (r(2) = 0.66) in children with body mass less than 20 kg. CONCLUSIONS: Low levels of ionized magnesium is an important finding in patients at the onset of CPB, which correlates well with the body mass of patients weighing less than 20 kg, and could be predicted by the regression curve. Based on these findings, hypomagnesemia can be prevented during CPB.


Assuntos
Ponte Cardiopulmonar , Cardiopatias Congênitas/cirurgia , Deficiência de Magnésio/sangue , Magnésio/sangue , Peso Corporal , Pré-Escolar , Feminino , Humanos , Magnésio/uso terapêutico , Deficiência de Magnésio/terapia , Masculino , Método Simples-Cego , Fatores de Tempo
12.
Neurosci Lett ; 333(3): 155-8, 2002 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-12429371

RESUMO

Injury to the peripheral nervous system can lead to spontaneous pain, hyperalgesia and allodynia. Previous studies have shown sprouting of Abeta-fibres into lamina II of the spinal cord dorsal horn after nerve injury and the formation of new synapses by these sprouts. Synaptophysin is a presynaptic vesicle protein, useful in the identification of synaptogenesis. Here we investigated whether synaptogenesis as measured by the expression of synaptophysin protein correlates with symptoms of neuropathic pain in rats with a chronic constriction injury (CCI) of the sciatic nerve. We used immunohistochemistry, Western immunoblotting and densitometry to study the distribution of synaptophysin and to quantify relative protein. Synaptophysin was increased in the ipsilateral dorsal horn with a peak level on day 14 and returned to baseline on day 21 post-CCI. Synaptophysin levels temporally correlated with thermal hyperalgesia but not with tactile allodynia. Our results indicate that thermal hyperalgesia in CCI significantly correlates with synaptogenesis within the superficial layers of the dorsal horn.


Assuntos
Nervo Isquiático/lesões , Medula Espinal/metabolismo , Sinaptofisina/metabolismo , Animais , Antígenos Nucleares/metabolismo , Western Blotting/métodos , Lateralidade Funcional/fisiologia , Imuno-Histoquímica/métodos , Ligadura , Masculino , Neurônios/metabolismo , Ratos , Ratos Sprague-Dawley , Medula Espinal/citologia , Sensação Térmica/fisiologia , Fatores de Tempo
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