Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 66
Filtrar
1.
Appl Opt ; 63(9): 2331-2339, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38568589

RESUMO

A new method, to the best of our knowledge, based on double-slit (DS) interference is proposed to accurately estimate the shear ratio of the system, with plane wave or spherical wave incidence. Existing shear ratio calibration methods, designed primarily for lateral shearing interferometry (LSI) with plane wave incidence, are not applicable to LSIs directly testing divergent or convergent spherical waves. Equations for calculating the shear ratio using the fringe spacing of the DS interferogram and the NA of the incident spherical wave are derived in this paper. The simulation result shows that the relative error of the shear ratio value is about 0.3%, when the shear ratio is 0.1. In the experiment, the quadriwave LSI is designed with a plug-in feature. The shear ratio at integer multiples of 1/6 Talbot distance from the modified Hartmann mask was calibrated using a DS, and the results were in good agreement with theoretical values, confirming the accuracy of the method. Subsequently, with the assistance of an inductance micrometer, the shear ratio was calibrated at intervals of 0.5 mm, and the results closely matched the theoretical variation of the shear ratio caused by displacement, confirming the high precision of the method.

2.
Angew Chem Int Ed Engl ; 63(21): e202401189, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38506220

RESUMO

This study introduces a novel approach for synthesizing Benzoxazine-centered Polychiral Polyheterocycles (BPCPHCs) via an innovative asymmetric carbene-alkyne metathesis-triggered cascade. Overcoming challenges associated with intricate stereochemistry and multiple chiral centers, the catalytic asymmetric Carbene Alkyne Metathesis-mediated Cascade (CAMC) is employed using dirhodium catalyst/Brønsted acid co-catalysis, ensuring precise stereo control as validated by X-ray crystallography. Systematic substrate scope evaluation establishes exceptional diastereo- and enantioselectivities, creating a unique library of BPCPHCs. Pharmacological exploration identifies twelve BPCPHCs as potent Nav ion channel blockers, notably compound 8 g. In vivo studies demonstrate that intrathecal injection of 8 g effectively reverses mechanical hyperalgesia associated with chemotherapy-induced peripheral neuropathy (CIPN), suggesting a promising therapeutic avenue. Electrophysiological investigations unveil the inhibitory effects of 8 g on Nav1.7 currents. Molecular docking, dynamics simulations and surface plasmon resonance (SPR) assay provide insights into the stable complex formation and favorable binding free energy of 8 g with C5aR1. This research represents a significant advancement in asymmetric CAMC for BPCPHCs and unveils BPCPHC 8 g as a promising, uniquely acting pain blocker, establishing a C5aR1-Nav1.7 connection in the context of CIPN.


Assuntos
Alcinos , Benzoxazinas , Metano , Metano/análogos & derivados , Metano/química , Metano/farmacologia , Alcinos/química , Benzoxazinas/química , Benzoxazinas/farmacologia , Benzoxazinas/síntese química , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacologia , Compostos Heterocíclicos/síntese química , Humanos , Estereoisomerismo , Analgésicos/química , Analgésicos/farmacologia , Analgésicos/síntese química , Estrutura Molecular , Catálise , Descoberta de Drogas , Animais
3.
Phys Rev Lett ; 130(26): 266302, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37450788

RESUMO

We report an unusual magnetoresistance that strengthens with the temperature in a dilute two-dimensional (2D) hole system in GaAs/AlGaAs quantum wells with densities p=1.98-0.99×10^{10}/cm^{2} where r_{s}, the ratio between Coulomb energy and Fermi energy, is as large as 20-30. We show that, while the system exhibits a negative parabolic magnetoresistance at low temperatures (≲0.4 K) characteristic of an interacting Fermi liquid, a positive magnetoresistance emerges unexpectedly at higher temperatures, and grows with increasing temperature even in the regime T∼E_{F}, close to the Fermi energy. This unusual positive magnetoresistance at high temperatures can be attributed to the viscous transport of 2D hole fluid in the hydrodynamic regime where holes scatter frequently with each other. These findings give insight into the collective transport of strongly interacting carriers in the r_{s}≫1 regime and new routes toward magnetoresistance at high temperatures.


Assuntos
Temperatura Baixa , Hidrodinâmica , Temperatura
4.
Langmuir ; 39(15): 5426-5439, 2023 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-37014907

RESUMO

Bacterial fouling is a persistent problem causing the deterioration and failure of functional surfaces for industrial equipment/components; numerous human, animal, and plant infections/diseases; and energy waste due to the inefficiencies at internal and external geometries of transport systems. This work gains new insights into the effect of surface roughness on bacterial fouling by systematically studying bacterial adhesion on model hydrophobic (methyl-terminated) surfaces with roughness scales spanning from ∼2 nm to ∼390 nm. Additionally, a surface energy integration framework is developed to elucidate the role of surface roughness on the energetics of bacteria and substrate interactions. For a given bacteria type and surface chemistry; the extent of bacterial fouling was found to demonstrate up to a 75-fold variation with surface roughness. For the cases showing hydrophobic wetting behavior, both increased effective surface area with increasing roughness and decreased activation energy with increased surface roughness was concluded to enhance the extent of bacterial adhesion. For the cases of superhydrophobic surfaces, the combination of factors including (i) the surpassing of Laplace pressure force of interstitial air over bacterial adhesive force, (ii) the reduced effective substrate area for bacteria wall due to air gaps to have direct/solid contact, and (iii) the reduction of attractive van der Waals force that holds adhering bacteria on the substrate were summarized to weaken the bacterial adhesion. Overall, this study is significant in the context of designing antifouling coatings and systems as well as explaining variations in bacterial contamination and biofilm formation processes on functional surfaces.


Assuntos
Aderência Bacteriana , Nanoestruturas , Animais , Humanos , Aderência Bacteriana/fisiologia , Propriedades de Superfície , Molhabilidade , Interações Hidrofóbicas e Hidrofílicas
5.
Soft Matter ; 19(29): 5609-5621, 2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37449660

RESUMO

Stimuli-responsive materials are increasingly needed for the development of smart electronic, mechanical, and biological devices and systems relying on switchable, tunable, and adaptable properties. Herein, we report a novel pH- and temperature-responsive binary supramolecular assembly involving a long-chain hydroxyamino amide (HAA) and an inorganic hydrotrope, boric acid, with highly tunable viscous and viscoelastic properties. The system under investigation demonstrates a high degree of control over its viscosity, with the capacity to achieve over four orders of magnitude of control through the concomitant manipulation of pH and temperature. In addition, the transformation from non-Maxwellian to Maxwellian fluid behavior could also be induced by changing the pH and temperature. Switchable rheological properties were ascribed to the morphological transformation between spherical vesicles, aggregated/fused spherical vesicles, and bicontinuous gyroid structures revealed by cryo-TEM studies. The observed transitions are attributed to the modulation of the head group spacing between HAA molecules under different pH conditions. Specifically, acidic conditions induce electrostatic repulsion between the protonated amino head groups, leading to an increased spacing. Conversely, under basic conditions, the HAA head group spacing is reduced due to the intercalation of tetrahydroxyborate, facilitated by hydrogen bonding.

6.
Soft Matter ; 18(28): 5282-5292, 2022 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-35789362

RESUMO

Recent studies have shown that solvated amphiphiles can form nanostructured self-assemblies called dynamic binary complexes (DBCs) in the presence of ions. Since the nanostructures of DBCs are directly related to their viscoelastic properties, it is important to understand how the nanostructures change under different solution conditions. However, it is challenging to obtain a three-dimensional molecular description of these nanostructures by utilizing conventional experimental characterization techniques or thermodynamic models. To this end, we combined the structural data from small angle X-ray scattering (SAXS) experiments and thermodynamic knowledge from coarse-grained Monte Carlo (CGMC) simulations to identify the detailed three-dimensional nanostructure of DBCs. Specifically, unbiased CGMC simulations are performed with SAXS-guided initial conditions, which aids us to sample accurate nanostructures in a computationally efficient fashion. As a result, an elliptical bilayer nanostructure is obtained as the most probable nanostructure of DBCs whose dimensions are validated by scanning electron microscope (SEM) images. Then, utilizing the obtained molecular model of DBCs, we could also explain the pH tunability of the system. Overall, our results from SAXS-guided unbiased CGMC simulations highlight that using potential energy combined with SAXS data, we can distinguish otherwise degenerate nanostructures resulting from the inherent ambiguity of SAXS patterns.

7.
Bioorg Med Chem ; 56: 116599, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-35041998

RESUMO

The aminobenzamide is selective to class I histone deacetylases (HDACs) and displays unique tight-binding/slow-off HDAC-binding mechanism. Herein, we report a series of 9-substituted purine aminobenzamides that selectively inhibit class I HDACs. The activities in vitro showed compound 9d exhibited 12 folds more potent than MS-275 against HDAC1 isoform and showed excellent inhibitory activity on cancer cells, including HCT-116, MDA-MB-231, K562 cell lines. The metabolic stability of 9d was much better than that of the well-known HDAC inhibitor SAHA. Pulse exposure test of western blot assay demonstrated that 9a, 9d induced histone acetylation in a similar manner to MS-275. Further biological validation demonstrated that 9d prevented cell transition from G1 phase to S phase by reducing Cyclin D1, CDK2 and lifting p21, induced early apoptosis by upregulating BAX and downregulating Bcl-2 in HCT-116 cells.


Assuntos
Antineoplásicos/farmacologia , Benzamidas/farmacologia , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/metabolismo , Purinas/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Benzamidas/síntese química , Benzamidas/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores de Histona Desacetilases/síntese química , Inibidores de Histona Desacetilases/química , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Purinas/química , Relação Estrutura-Atividade
8.
Acta Biochim Biophys Sin (Shanghai) ; 53(11): 1516-1526, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34536273

RESUMO

Vascularization is an important early indicator of osteogenesis involving biomaterials. Bone repair and new bone formation are associated with extensive neovascularization. Silicon-based biomaterials have attracted widespread attention due to their rapid vascularization. Although calcium phosphate cement (CPC) is a mature substitute for bone, the application of CPC is limited by its slow degradation and insufficient promotion of neovascularization. Calcium silicate (CS) has been shown to stimulate vascular endothelial proliferation. Thus, CS may be added to CPC (CPC-CS) to improve the biocompatibility and neovascularization of CPC. In the early phase of bone repair (the inflammatory phase), macrophages accumulate around the biomaterial and exert both anti- and pro-inflammatory effects. However, the effect of CPC-CS on macrophage polarization is not known, and it is not clear whether the effect on neovascularization is mediated through macrophage polarization. In the present study, we explored whether silicon-mediated macrophage polarization contributes to vascularization by evaluating the CPC-CS-mediated changes in the immuno-environment under different silicate ion contents both in vivo and in vitro. We found that the silicon released from CPC-CS can promote macrophage polarization into the M2 phenotype and rapid endothelial neovascularization during bone repair. Dramatic neovascularization and osteogenesis were observed in mouse calvarial bone defects implanted with CPC-CS containing 60% CS. These findings suggest that CPC-CS is a novel biomaterial that can modulate immune response, promote endothelial proliferation, and facilitate neovascularization and osteogenesis. Thus, CPC-CS shows potential as a bone substitute material.


Assuntos
Cimentos Ósseos/farmacologia , Regeneração Óssea/efeitos dos fármacos , Compostos de Cálcio/farmacologia , Fosfatos de Cálcio/farmacologia , Silicatos/farmacologia , Silício/farmacologia , Crânio/efeitos dos fármacos , Animais , Cimentos Ósseos/química , Compostos de Cálcio/química , Fosfatos de Cálcio/química , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ativação de Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neovascularização Fisiológica/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Células RAW 264.7 , Silicatos/química , Silício/química , Crânio/irrigação sanguínea , Crânio/lesões
9.
Compr Rev Food Sci Food Saf ; 20(3): 3093-3134, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33949079

RESUMO

Illness as the result of ingesting bacterially contaminated foodstuffs represents a significant annual loss of human quality of life and economic impact globally. Significant research investment has recently been made in developing new materials that can be used to construct food contacting tools and surfaces that might minimize the risk of cross-contamination of bacteria from one food item to another. This is done to mitigate the spread of bacterial contamination and resultant foodborne illness. Internet-based literature search tools such as Web of Science, Google Scholar, and Scopus were utilized to investigate publishing trends within the last 10 years related to the development of antimicrobial and antifouling surfaces with potential use in food processing applications. Technologies investigated were categorized into four major groups: antimicrobial agent-releasing coatings, contact-based antimicrobial coatings, superhydrophobic antifouling coatings, and repulsion-based antifouling coatings. The advantages for each group and technical challenges remaining before wide-scale implementation were compared. A diverse array of emerging antimicrobial and antifouling technologies were identified, designed to suit a wide range of food contact applications. Although each poses distinct and promising advantages, significant further research investment will likely be required to reliably produce effective materials economically and safely enough to equip large-scale operations such as farms, food processing facilities, and kitchens.


Assuntos
Anti-Infecciosos , Incrustação Biológica , Antibacterianos , Anti-Infecciosos/farmacologia , Bactérias , Incrustação Biológica/prevenção & controle , Humanos , Qualidade de Vida
10.
J Org Chem ; 85(21): 13920-13928, 2020 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-33034191

RESUMO

A blue light-promoted formal [4+1]-annulation of diazoacetates with o-aminoacetophenones has been reported, which provides an environmentally friendly method for the synthesis of polysubstituted indoline derivatives in moderate to good yields with excellent diastereoselectivities. Detailed mechanistic studies through density functional theory calculations reveal that the (E)-enol species is the key intermediate in this transformation, and the excellent diastereoselectivity is enabled via H-bonding in the intramolecular Aldol-type addition.

11.
BMC Neurol ; 20(1): 122, 2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-32252673

RESUMO

BACKGROUND: Reversible splenial lesion syndrome (RESLES) is known to cause severe psychiatric symptoms but is also a very rare clinical disease in which the specific aetiology is unknown. According to current reports, there are major causes of the disease, including viral or bacterial infection, epilepsy, anti-epileptic drug withdrawal, high-altitude cerebral oedema, and metabolic disorders such as hypoglycaemia and hypernatraemia. In this article, we report a patient with thrombotic thrombocytopenic purpura (TTP) who presented with RESLES. CASE PRESENTATION: A 34-year-old female patient who presented with fever and progression of disorder of consciousness was eventually diagnosed with RESLES based on brain imaging. Moreover, clinical features and peripheral smears demonstrating schistocytes and thrombocytopenia confirmed a diagnosis of TTP. RESLES can be improved by plasma exchange therapy. CONCLUSION: This rare case highlights the occurrence of RESLES as a presenting feature of the expanding list of unusual neurological manifestations of TTP.


Assuntos
Doenças do Sistema Nervoso Central/complicações , Doenças do Sistema Nervoso Central/patologia , Corpo Caloso/patologia , Púrpura Trombocitopênica Trombótica/complicações , Adulto , Corpo Caloso/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Neuroimagem , Troca Plasmática , Púrpura Trombocitopênica Trombótica/terapia , Síndrome
12.
Nano Lett ; 18(10): 6538-6543, 2018 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-30185048

RESUMO

The Drude model is one of the most fundamental models used to understand the electronic carrier transport in materials, including recently discovered topological materials. Here, we present a magneto-transport study revealing the non-Drude transport behavior in a heterostructure of topological crystalline insulator (TCI) SnTe and band insulator PbTe which exhibits a nonsaturating linear magneto-resistance (MR) effect, a novel phenomenon widely observed in topological materials with gapless dispersion. It is shown that in the van der Pauw geometry in which the longitudinal and transverse magneto-resistances are measured to extract the magneto-conductivity, the two-band Drude model is not sufficient to self-consistently describe both the longitudinal and transverse magneto-conductivities. Furthermore, in the Corbino geometry, which directly measures the longitudinal magneto-conductivity σ xx( B) for a straightforward comparison with the Drude model, the MR, 1/σ xx( B), still reveals a large linear MR effect, in direct discrepancy with the Drude model. While shining further light on the multiple-carrier transport in TCI, this study highlights an unusual magneto-transport character of topological materials that challenges the standard Drude picture of electron transport.

13.
Chem Pharm Bull (Tokyo) ; 66(4): 439-451, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29607910

RESUMO

The novel hydroxamates containing purine scaffold were designed, synthesized and screened for their biological activities as histone deacetylase (HDAC) inhibitors. Some of them exhibited excellent acti-HDACs activities and antiproliferative activities, the most promising compound was 7m'. Western blot analysis indicated the compounds 7f', 7l', 7m', 7o' could increase histone H3 acetylation levels in HCT116 and K562 cell lines, and 7m' increased the level of acetyl histone H3 in a dose-dependent manner, which is similar to the behavior of suberoylanilide hydroxamic acid (SAHA). Molecular docking study revealed that the conformation of 7m' in the active site of HDAC2 was similar to positive drug SAHA, which were oriented with the hydroxamic acid towards the catalytic center and formed metal binding with zinc ion.


Assuntos
Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/metabolismo , Ácidos Hidroxâmicos/farmacologia , Purinas/farmacologia , Relação Dose-Resposta a Droga , Células HCT116 , Inibidores de Histona Desacetilases/síntese química , Inibidores de Histona Desacetilases/química , Humanos , Ácidos Hidroxâmicos/síntese química , Ácidos Hidroxâmicos/química , Células K562 , Simulação de Acoplamento Molecular , Estrutura Molecular , Purinas/química , Relação Estrutura-Atividade
14.
Tumour Biol ; 39(7): 1010428317708547, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28714365

RESUMO

Several studies have revealed the potential of normalizing tumor vessels in anti-angiogenic treatment. Recombinant human endostatin is an anti-angiogenic agent which has been applied in clinical tumor treatment. Our previous research indicated that gold nanoparticles could be a nanoparticle carrier for recombinant human endostatin delivery. The recombinant human endostatin-gold nanoparticle conjugates normalized vessels, which improved chemotherapy. However, the mechanism of recombinant human endostatin-gold nanoparticle-induced vascular normalization has not been explored. Anterior gradient 2 has been reported to be over-expressed in many malignant tumors and involved in tumor angiogenesis. To date, the precise efficacy of recombinant human endostatin-gold nanoparticles on anterior gradient 2-mediated angiogenesis or anterior gradient 2-related signaling cohort remained unknown. In this study, we aimed to explore whether recombinant human endostatin-gold nanoparticles could normalize vessels in metastatic colorectal cancer xenografts, and we further elucidated whether recombinant human endostatin-gold nanoparticles could interrupt anterior gradient 2-induced angiogenesis. In vivo, it was indicated that recombinant human endostatin-gold nanoparticles increased pericyte expression while inhibit vascular endothelial growth factor receptor 2 and anterior gradient 2 expression in metastatic colorectal cancer xenografts. In vitro, we uncovered that recombinant human endostatin-gold nanoparticles reduced cell migration and tube formation induced by anterior gradient 2 in human umbilical vein endothelial cells. Treatment with recombinant human endostatin-gold nanoparticles attenuated anterior gradient 2-mediated activation of MMP2, cMyc, VE-cadherin, phosphorylation of p38, and extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) in human umbilical vein endothelial cells. Our findings demonstrated recombinant human endostatin-gold nanoparticles might normalize vessels by interfering anterior gradient 2-mediated angiogenesis in metastatic colorectal cancer.


Assuntos
Neoplasias Colorretais/tratamento farmacológico , Endostatinas/administração & dosagem , Nanopartículas Metálicas/administração & dosagem , Neovascularização Patológica/tratamento farmacológico , Proteínas/genética , Inibidores da Angiogênese/administração & dosagem , Inibidores da Angiogênese/química , Animais , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Endostatinas/química , Endostatinas/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Ouro/administração & dosagem , Ouro/química , Xenoenxertos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Nanopartículas Metálicas/química , Camundongos , Mucoproteínas , Metástase Neoplásica , Proteínas de Neoplasias/biossíntese , Neovascularização Patológica/genética , Neovascularização Patológica/patologia , Proteínas Oncogênicas , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/química , Proteínas Recombinantes/genética
15.
Eur Spine J ; 26(12): 3084-3095, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28647763

RESUMO

PURPOSE: To compare the clinical effectiveness of decompression plus fusion and decompression alone for patients with degenerative lumbar spondylolisthesis, a systematic review and meta-analysis of all available evidence was performed. METHODS: A search of the literature was conducted on PubMed/MEDLINE, EMBASE, and the Cochrane Collaboration Library. Relevant studies comparing decompression plus fusion and decompression alone were selected according to eligibility criteria. Predefined endpoints were extracted and meta-analyzed from the identified studies. RESULTS: Four randomized controlled trials and 13 observational studies were eligible. The pooled data revealed that fusion was associated with significantly higher rates of satisfaction and lower leg pain scores when compared with decompression alone. However, fusion significantly increased the intraoperative blood loss, operative time and hospital stay. Both techniques had similar ODI, back pain scores, complication rate, and reoperation rate. CONCLUSIONS: Based on the available evidence, decompression plus fusion maybe be better than decompression alone in the treatment of degenerative spondylolisthesis. Fusion had advantages of improvement of clinical satisfaction, as well as reduction of postoperative leg pain, with similar complication rate to decompression alone.


Assuntos
Descompressão Cirúrgica , Vértebras Lombares/cirurgia , Fusão Vertebral , Espondilolistese/cirurgia , Perda Sanguínea Cirúrgica , Descompressão Cirúrgica/efeitos adversos , Descompressão Cirúrgica/métodos , Descompressão Cirúrgica/estatística & dados numéricos , Humanos , Tempo de Internação , Duração da Cirurgia , Fusão Vertebral/efeitos adversos , Fusão Vertebral/métodos , Fusão Vertebral/estatística & dados numéricos , Resultado do Tratamento
16.
Acta Biochim Biophys Sin (Shanghai) ; 49(2): 101-109, 2017 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-28172101

RESUMO

Mesenchymal stem cells (MSCs) have been isolated and identified separately from the three components of intervertebral disc, i.e. annulus fibrosus (AF), nucleus pulposus (NP), and cartilage endplate (CEP). However, few studies have been carried out to compare the properties of these three kinds of stem cells, especially their migration ability which is essential for their potential clinical application. In this study, MSCs were isolated from AF, NP, and CEP, respectively, of human degenerated discs and identified by surface markers and multilineage differentiation assay at passage 3. These three types of stem cells were named as AF-MSCs, NP-MSCs, and CEP-MSCs. Then, their biological characteristics were compared in terms of proliferation, passage, colony formation, migration, and invasion capacity. Results showed that all the three types of cells were identified as MSCs and had similar characteristics in proliferation, passage, and colony formation capacity. CEP-MSCs showed the highest migration and invasion potency, while NP-MSCs showed the lowest migration ability and almost no invasion potency, suggesting that CEP-MSCs had the most powerful properties of migration and invasion when compared with AF-MSCs and NP-MSCs. It was also found that the expression of CXCR4 was higher in CEP-MSCs than in the other two, suggesting that SDF-1/CXCR4 axis may play significant roles in the migration of these cells.


Assuntos
Movimento Celular , Quimiocina CXCL12 , Degeneração do Disco Intervertebral , Células-Tronco Mesenquimais , Receptores CXCR4 , Células-Tronco Adultas/patologia , Células-Tronco Adultas/fisiologia , Anel Fibroso/patologia , Anel Fibroso/fisiologia , Biomarcadores/metabolismo , Diferenciação Celular , Movimento Celular/fisiologia , Proliferação de Células , Células Cultivadas , Quimiocina CXCL12/genética , Quimiocina CXCL12/metabolismo , Feminino , Humanos , Degeneração do Disco Intervertebral/genética , Degeneração do Disco Intervertebral/patologia , Masculino , Células-Tronco Mesenquimais/fisiologia , Pessoa de Meia-Idade , Núcleo Pulposo/patologia , Núcleo Pulposo/fisiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores CXCR4/genética , Receptores CXCR4/metabolismo
17.
Nano Lett ; 16(12): 7925-7929, 2016 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-27960525

RESUMO

Organometal halide perovskite has emerged as a promising material for solar cells and optoelectronics. Although the long diffusion length of photogenerated carriers is believed to be a critical factor responsible for the material's high efficiency in solar cells, a direct study of carrier transport over long distances in organometal halide perovskites is still lacking. We fabricated highly oriented crystalline CH3NH3PbI3 (MAPbI3) thin-film lateral transport devices with long channel length (∼120 µm). By performing spatially scanned photocurrent imaging measurements with local illumination, we directly show that the perovskite films prepared here have very long transport lengths for photogenerated carriers, with a minority carrier (electron) diffusion length on the order of 10 µm. Our approach of applying scanning photocurrent microscopy to organometal halide perovskites may be further used to elucidate the carrier transport processes and the vastly different carrier diffusion lengths (∼100 nm to 100 µm) in different types of organometal halide perovskites.

18.
Macromol Biosci ; 24(5): e2300476, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38245857

RESUMO

Peripheral nerve injuries (PNI) represent a prevalent and severe category of damage resulting from traumatic incidents. Predominantly, the deficiency in nerve regeneration can be ascribed to enduring inflammatory reactions, hence imposing substantial clinical implications for patients. Fisetin, a flavonoid derived from plants, is naturally present in an array of vegetables and fruits, including strawberries, apples, onions, and cucumbers. It exhibits immunomodulatory properties through the reduction of inflammation and oxidative stress. In the present research, a nerve defect is addressed for the first time utilizing a scaffold primed for controlled fisetin release. In this regard, fisetin-loaded chitosan hydrogels are incorporated into the lumen of polycaprolactone (PCL) nerve guide conduits (NGCs). The hydrogel maintained a steady release of an appropriate fisetin dosage. The study outcomes indicated that the fisetin/chitosan/polycaprolactone (FIS/CS/PCL) NGCs amplified Schwann cell proliferation and neural expression, curtailed oxidative stress, alleviated inflammation, and improved functions, electrophysiological properties, and morphology. This pioneering scaffold has the potential to contribute significantly to the field of neuroengineering.


Assuntos
Quitosana , Flavonóis , Hidrogéis , Inflamação , Regeneração Nervosa , Estresse Oxidativo , Poliésteres , Flavonóis/farmacologia , Quitosana/química , Quitosana/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Regeneração Nervosa/efeitos dos fármacos , Poliésteres/química , Poliésteres/farmacologia , Inflamação/tratamento farmacológico , Inflamação/patologia , Células de Schwann/efeitos dos fármacos , Células de Schwann/metabolismo , Alicerces Teciduais/química , Ratos , Regeneração Tecidual Guiada/métodos , Proliferação de Células/efeitos dos fármacos , Flavonoides/farmacologia , Flavonoides/química , Traumatismos dos Nervos Periféricos/tratamento farmacológico , Traumatismos dos Nervos Periféricos/patologia , Traumatismos dos Nervos Periféricos/terapia
20.
Mar Life Sci Technol ; 6(1): 68-83, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38433967

RESUMO

Mesopelagic fish (meso-fish) are central species within the Southern Ocean (SO). However, their ecosystem role and adaptive capacity to climate change are rarely integrated into protected areas assessments. This is a pity given their importance as crucial prey and predators in food webs, coupled with the impacts of climate change. Here, we estimate the habitat distribution of nine meso-fish using an ensemble model approach (MAXENT, random forest, and boosted regression tree). Four climate model simulations were used to project their distribution under two representative concentration pathways (RCP4.5 and RCP8.5) for short-term (2006-2055) and long-term (2050-2099) periods. In addition, we assess the ecological representativeness of protected areas under climate change scenarios using meso-fish as indicator species. Our models show that all species shift poleward in the future. Lanternfishes (family Myctophidae) are predicted to migrate poleward more than other families (Paralepididae, Nototheniidae, Bathylagidae, and Gonostomatidae). In comparison, lanternfishes were projected to increase habitat area in the eastern SO but lose area in the western SO; the opposite was projected for species in other families. Important areas (IAs) of meso-fish are mainly distributed near the Antarctic Peninsula and East Antarctica. Negotiated protected area cover 23% of IAs at present and 38% of IAs in the future (RCP8.5, long-term future). Many IAs of meso-fish still need to be included in protected areas, such as the Prydz Bay and the seas around the Antarctic Peninsula. Our results provide a framework for evaluating protected areas incorporating climate change adaptation strategies for protected areas management. Supplementary Information: The online version contains supplementary material available at 10.1007/s42995-023-00188-9.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA