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1.
Brain Struct Funct ; 2020 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-32385518

RESUMO

Rational decision theories posit that good choices should be based solely on information that is relevant to the choice at hand. However, introducing an inferior option that would never be chosen can influence choices among other relevant options, known as decoy effect. We used functional magnetic resonance imaging (fMRI) combined with a simple gambling task to investigate the neural signature of decision-making in or against the influence of the decoy effect in inferior and superior phantom decoy conditions. The fMRI results show that compared with choosing against the influence of the dominated phantom inferior option, choosing in the influence of the same option was associated with stronger activation in bilateral caudate and weaker functional connectivity between the left ventral anterior cingulate cortex (vACC) and the left caudate. Phantom inferior effect selectively enhanced the connectivity from the caudate to the vACC but not vice versa. Choosing in the influence of the dominated phantom superior option engaged greater activity in the left dorsal ACC and stronger functional connectivity between the left dACC and bilateral anterior insula. Furthermore, the direction of the phantom superior effect was restricted from left dACC to the anterior insula, but not vice versa. Our findings suggest that a phantom inferior decoy may boost the value of the target via the reward network, whereas a phantom superior decoy may diminish the value of the target option via the aversion network. Our study provides neural evidence to support that valuation is context dependent and delineates differential neural networks underlying the influence of unavailable inferior and superior decoy options on our decision-making.

2.
J Dent ; : 103346, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-32325176

RESUMO

OBJECTIVES: The fracture strengths of four types of occlusal veneers and a traditional full crown ceramic restoration and the influence of preparation design on the stress of restorations were examined. METHODS: Forty intact maxillary premolars randomly divided into five groups were prepared based on the demands of type O (occlusal surface coverage), OF (occlusal and lingual surface coverage), POF (occlusal, lingual, and mesial surface coverage), and POFP (occlusal, lingual, mesial, and distal surface coverage) veneers and full crown, and then restored by glass ceramic. Specimens were subjected to fracture resistance tests after cyclic loading. The fracture strengths and modes were analyzed statistically. The level of significance was set at α = 0.05. One maxillary premolar was prepared for type O, OF, POF, POFP veneer and full crown, and then scanned to establish finite element models. The mean fracture load was applied vertically to calculate the maximum principal stress on the ceramic. RESULTS: Type O veneer showed higher fracture strength than type POF and POFP veneers (P < 0.05). Both type O and OF veneers exhibited higher fracture strength than full crown (P < 0.05). No significant difference in failure mode was observed. The maximum principal stress for type O, OF, POF, POFP veneers, and full crown increased progressively and concentrated at the bonding surface directly beneath the loading area. CONCLUSIONS: Four types of occlusal veneer showed fracture strengths that considerably exceeded normal biting forces. They represent conservative alternatives to full crowns and present a viable treatment for severely worn teeth. CLINICAL SIGNIFICANCE: The occlusal veneers with different preparation designs, including type O, OF, POF and POFP veneers, show higher fracture resistances than traditional full coverage crowns that considerably exceed the normal biting forces. Therefore, these represent conservative alternatives to crown restorations and present a viable treatment for restoring severely worn teeth.

3.
Clin Oral Investig ; 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32034548

RESUMO

OBJECTIVES: To compare stress distribution and failure probability in maxillary premolars restored by simple occlusal veneer (SOV) and buccal-occlusal veneer (BOV) with 3 different CAD/CAM materials. MATERIALS AND METHODS: A maxillary premolar was digitized by a micro-CT scanner. Three-dimensional dynamic scan data were transformed, and finite element models of 2 different models (SOV and BOV restored teeth) were designed. Three different CAD/CAM materials, including lithium disilicate glass ceramic (LD) IPS e.max CAD, polymer-infiltrated ceramic-network (PICN) Vita Enamic, and resin nano-ceramic (RNC) Lava Ultimate, were designated to both veneers. Maximum principle stresses were determined by applying a 300-N axial load to the occlusal surface. Weibull analyses were performed to calculate the failure probability of the models. RESULTS: LD-restored teeth showed the highest stress in the veneer, lowest stress in substrate teeth, and lowest failure probability for the overall system; RNC-restored teeth showed the lowest stress in the veneer, highest stress in substrate teeth, and highest failure probability. No significant differences were found in the cement layer among the different models. No significant differences of stress and failure probability existed between SOV and BOV preparations. CONCLUSIONS: CAD/CAM composite resin occlusal veneers bear lower maximum stress than ceramic veneers. Teeth restored by composite veneers are more prone to failure than those restored by ceramic veneers. Additional reduction of the buccal surface did not increase the stress on the occlusal veneer under axial load. CLINICAL RELEVANCE: Both occlusal veneers could be used under physiological masticatory force. CAD/CAM glass ceramic was safer than composite resins.

4.
J Adhes Dent ; 21(3): 273-280, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31165106

RESUMO

PURPOSE: In order to provide an experimental basis for the use of baicalein (BAI) as an enzyme inhibitor to improve resin-dentin bonding durability, this study explored the effect of BAI on the expression of matrix metalloproteinases (MMPs) and cathepsins in human dental pulp cells (HDPCs). MATERIALS AND METHODS: The effects of various concentrations of BAI on the viability and cell cycle arrest of HDPCs were investigated in vitro. qPCR and Western blot analysis were performed to determine the effects of BAI on the expression of MMP-2, MMP-9, cathepsin-B, and cathepsin-K in HDPCs. Thermocycling (aging) was performed to determine the effect of BAI on the microtensile bond strength of aged resin-dentin bonding. RESULTS: Our results showed that BAI at concentrations below 25 µmol/l did not affect cell viability in HDPCs. Moreover, low concentrations of BAI effectively inhibited the expression of MMP-2, MMP-9, cathepsin-B, and cathepsin-K in HDPCs and improved the strength of aged resin-dentin bonding. CONCLUSION: BAI is a promising preconditioner for improving the durability of resin-dentin bonding by protecting against collagen degradation via the inhibition of MMPs and cathepsins.


Assuntos
Colagem Dentária , Adesivos Dentinários , Colágeno , Polpa Dentária , Dentina , Flavanonas , Humanos , Resistência à Tração
5.
Sheng Wu Gong Cheng Xue Bao ; 35(6): 1079-1087, 2019 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-31232004

RESUMO

Here we investigate the physical and chemical properties of chiral self-assembling peptides and the role of uterine trauma regeneration. The circular dichroism was used to analyze secondary structure of chiral self-assembled peptide, and Congo red staining was used to observe the macroscopic process of peptide self-assembling. Erythrocyte lysis assay was used to examine the cleavage of peptide on cell membrane. The nanofiber scaffolds self-assembled by Chiral self-assembling peptides were used as the three-dimensional culture material to observe the growth effect of Hela cell. CCK-8 (cell counting kit-8) was used to study cell viability level between 2D (2-dimensional) and 3D (3-dimensional) culture environment. Rats endometrium curettage model was founded to evaluate the changes by immunohistochemistry staining and and HE staining. The secondary structure of chiral self-assembling peptides was stable ß-sheet, and peptide could form dense membrane structure after 24 hours self-assembling cultured in salt ions. There was no harmful for the cell membrane of the peptide before and after self-assembling. Animal experiments show that chiral self-assembling peptide can significantly reduce the inflammatory response, promote the production of neovascularization, and accelerate the repair process. Chiral self-assembling peptide, as a new type of scaffold material, can construct a three-dimensional cell culture environment and used to repair uterine trauma.


Assuntos
Endométrio , Nanofibras , Animais , Feminino , Células HeLa , Humanos , Peptídeos , Ratos , Regeneração
6.
Int J Nanomedicine ; 14: 3043-3054, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31118621

RESUMO

Background: Many studies have shown that the size of nanotube (NT) can significantly affect the behavior of osteoblasts on titanium-based materials. But the weak bonding strength between NT and substrate greatly limits their application. Purpose: The objective of this study was to compare the stability of NT and nanopore (NP) coatings, and further prepare antibacterial titanium-based materials by loading LL37 peptide in NP structures. Methods: The adhesion strength of NT and NP layers was investigated using a scratch tester. The proliferation and differentiation of MC3T3-E1 cells on different substrates were evaluated in vitro by CCK8, alkaline phosphatase activity, mineralization and polymerase chain reaction assays. The antibacterial rates of NP and NP/LL37 were also measured by spread plate method. Moreover, the osteogenesis around NP and NP/LL373 in vivo was further evaluated using uninfected and infected models. Results: Scratch test proved that the NP layers had stronger bonding strength with the substrates due to their continuous pore structures and thicker pipe walls than the independent NT structures. In vitro, cell results showed that MC3T3-E1 cells on NP substrates had better early adhesion, spreading and osteogenic differentiation than those of NT group. In addition, based on the drug reservoir characteristics of porous materials, the NP substrates were also used to load antibacterial LL37 peptide. After loading LL37, the antibacterial and osteogenic induction abilities of NP were further improved, thus significantly promoting osteogenesis in both uninfected and infected models. Conclusion: We determined that the NP layers had stronger bonding strength than NT structures, and the corresponding NP materials might be more suitable than NT for preparing drug-device combined titanium implants for bone injury treatment.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Nanoporos , Osteogênese/efeitos dos fármacos , Titânio/farmacologia , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Liberação Controlada de Fármacos , Imageamento Tridimensional , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos , Nanoporos/ultraestrutura , Nanotubos/química , Nanotubos/ultraestrutura , Osteoblastos/citologia , Próteses e Implantes , Ratos , Propriedades de Superfície
7.
ACS Nano ; 13(2): 2334-2340, 2019 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-30735355

RESUMO

Two dimensional (2D) materials possessing ferroelectric/ferromagnetic orders and especially low-magnetic-field controlled magnetoelectricity have great promise in spintronics and multistate data storage. However, ferroelectric and magnetoelectric (ME) dipoles in the atom-thick 2D materials are difficult to be realized due to structural inversion symmetry, thermal actuation, and depolarized field. To overcome these difficulties, the monolayer structure must possess an in-plane inversion asymmetry in order to provide out-of-plane ferroelectric polarization. Herein, crystal chemistry is adopted to engineer specific atomic displacement in monolayer ReS2 to change the crystal symmetry to induce out-of-plane ferroelectric polarization at room temperature. The cationic Re vacancy in the atom-displaced ReS2 monolayer causes spin polarization of two immediate neighbor sulfur atoms to generate magnetic ordering, and the ferroelectric distortion near the Re vacancy locally tunes the ferromagnetic order thereby triggering low-magnetic-field controlled ME polarization at about 28 K. As a result, 2D ME coupling multiferroics is achieved. Our results not only reveal a design methodology to attain coexistence of ferroelectric and ferromagnetic orders in 2D materials but also provide insights into magnetoelectricity in 2D materials.

8.
Nanotechnology ; 30(4): 045101, 2019 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-30485249

RESUMO

DNA combing is a widely used method for stretching and immobilising DNA molecules on a surface. Fluorescent labelling of genomic information enables high-resolution optical analysis of DNA at the single-molecule level. Despite its simplicity, the application of DNA combing in diagnostic workflows is still limited, mainly due to difficulties in analysing multiple small-volume DNA samples in parallel. Here, we report a simple and versatile microfluidic DNA combing technology (µDC), which allows manipulating, stretching and imaging of multiple, microliter scale DNA samples by employing a manifold of parallel microfluidic channels. Using DNA molecules with repetitive units as molecular rulers, we demonstrate that the µDC technology allows uniform stretching of DNA molecules. The stretching ratio remains consistent along individual molecules as well as between different molecules in the various channels, allowing simultaneous quantitative analysis of different samples loaded into parallel channels. Furthermore, we demonstrate the application of µDC to characterise UVB-induced DNA damage levels in human embryonic kidney cells and the spatial correlation between DNA damage sites. Our results point out the potential application of µDC for quantitative and comparative single-molecule studies of genomic features. The extremely simple design of µDC makes it suitable for integration into other microfluidic platforms to facilitate high-throughput DNA analysis in biological research and medical point-of-care applications.


Assuntos
DNA/análise , Técnicas Analíticas Microfluídicas/métodos , Imagem Individual de Molécula/métodos , DNA/efeitos da radiação , Dano ao DNA , Células HEK293 , Humanos , Imagem Óptica , Sistemas Automatizados de Assistência Junto ao Leito
9.
Int J Psychol ; 54(5): 604-611, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30010188

RESUMO

Individuals often need to make critical decisions even when they are in a fatigued state. Mental fatigue may lead to increased susceptibility to distraction and poor information processing but it is unclear exactly how fatigue shapes individuals' decision-making. We studied how mental fatigue influences sensitivity to contextual information, indexed as decoy bias. Mental fatigue was induced using a multi-source interference task, and decoy bias was assessed using a gambling task, in 124 young adults. Results showed that mental fatigue increased decoy bias through enhanced perceptual salience of contextual cues, but only in males. The findings provide insight into a gender-specific relationship between fatigue and poor judgments. This study extends the current literature on links between fatigue and poor decision-making by documenting a possible mechanism of the association. The results may have practical implications for designing optimal working hours and safeguarding people from suboptimal decisions.


Assuntos
Cognição/fisiologia , Tomada de Decisões/fisiologia , Fadiga Mental/psicologia , Adolescente , Adulto , Viés , Feminino , Humanos , Masculino , Adulto Jovem
10.
Soft Matter ; 14(43): 8780-8791, 2018 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-30338769

RESUMO

Fragmenting DNA into short pieces is an essential manipulation in many biological studies, ranging from genome sequencing to molecular diagnosis. Among various DNA fragmentation methods, microfluidic hydrodynamic DNA fragmentation has huge advantages especially in terms of handling small-volume samples and being integrated into automatic and all-in-one DNA analysis equipment. Despite the fast progress in experimental studies and applications, a systematic understanding of how DNA molecules are distributed, stretched and fragmented in a confined microfluidic field is still lacking. In this work, we investigate the extension and fragmentation of DNA in a typical contractive microfluidic field, which consists of a shear flow-dominated area and an elongational flow-dominated area, using the Brownian dynamics-computational fluid dynamics method. Our results show that the shear flow at the straight part of the microfluidic channel and the elongational flow at the contractive bottleneck together determine the performance of DNA fragmentation. The average fragment size of DNA decreases with the increase of the strain rate of the elongational flow, and the upstream shear flow can significantly precondition the conformation of DNA to produce shorter and more uniform fragments. A systematic study of the dynamics of DNA fragmentation shows that DNA tends to break at the mid-point when the strain rate of elongational flow is small, and the breakage point largely deviates from the midpoint as the strain rate increases. Our simulation of the thorough DNA fragmentation process in a realistic microfluidic field agrees well with experimental results. We expect that our study can shed new light on the development of future microfluidic devices for DNA fragmentation and integrated DNA analysis devices.


Assuntos
Simulação por Computador , DNA/química , Hidrodinâmica , Dispositivos Lab-On-A-Chip , DNA/metabolismo , Modelos Moleculares , Conformação de Ácido Nucleico
11.
J Biomed Nanotechnol ; 14(11): 1965-1978, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30165932

RESUMO

Implant surface modification that provides local sustained release of osteoinductive therapeutic agents enhances implant stability. We designed a mesoporous TiO2-layered titanium implant (MLT) by modified anodization technique that allowed local sustained release of zoledronic acid up to 21 days. Mesoporous layer has pore size 15 nm, depth ∼30 µm, volume 0.32 cm3/g, surface area 112.3 m2/g, surface roughness 20 nm and water contact angle 18.3°. Zoledronic acid-loaded MLT (MLT-Z) was biocompatible, showed anabolic effect on bone forming osteoblasts and catabolic effect on bone resorbing osteoclasts. MLT or MLT-Z implants were implanted in osteoporotic rat-tail vertebrae. Smooth implant in healthy rats were used as a positive control. Histomorphometric analysis showed that bone implant contact of smooth implant in osteoporotic rats was reduced by 4.1-fold compared to healthy rats and MLT-Z rescued the effect by 53%. Similar effect was observed in implant fixation, mechanical stability, BV/TV ratio, Tb.N, Tb.Th and OI% among the groups. Histological and µ-CT images strongly supported the above-mentioned findings. In conclusion, a novel surface-fabricated MLT-Z gives local sustained drug release, robustly enhances implant osseointegration and stability in osteoporotic condition, suggesting it as a promising implant model for patients with compromised bone quality.


Assuntos
Osseointegração , Animais , Preparações de Ação Retardada , Próteses e Implantes , Ratos , Propriedades de Superfície , Titânio , Ácido Zoledrônico
12.
J Cell Physiol ; 233(12): 9458-9472, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29995982

RESUMO

Craniofacial defects can cause morbidness. Adipose-derived stem cells (ADSCs) have shown great promise for osteogeneration and vascularization; therefore cocultures of differentiated ADSCs are explored to increase bone and vessel formation. In this study, ADSCs were induced into osteogenic ADSCs (os-ADSCs) and endothelial ADSCs (endo-ADSCs) cells, which were then cocultured in variable proportions (os-ADSCs/endo-ADSCs = 2:1, 1:1, 1:2). The os-ADSCs in a ratio of 1:1 expressed more ALP, RUNX2 and COL-I, whereas VEGF, vWF and CD31 were upregulated in the endo-ADSCs of this group. Next generation RNA sequencing (RNA-seq) was performed to evaluate the molecular mechanisms of cocultured ADSCs. The os-ADSCs and endo-ADSCs interacted with each other during osteogenic and angiogenic differentiation, especially at the ratio of 1:1, and were regulated by vascular-related genes, cell-mediated genes, bone-related genes and the transforming growth factor ß signaling pathway (TGF-ß), mitogen-activated protein kinase signaling pathway (MAPK) and wnt signaling pathway (Wnt). Angptl4, apoe, mmp3, bmp6, mmp13 and fgf18 were detected to be up-regulated, and cxcl12 and wnt5a were down-regulated. The results showed that the gene expression levels were consistent with that in RNA-seq. The cells were then seeded into self-assembling peptide RADA16-I scaffolds as cocultures (1:1) and monocultures (ADSCs, os-ADSCs, endo-ADSCs). The results showed that the cells of all groups grew and proliferated well on the scaffolds, and the cocultured group exhibited better osteogeneration and vascularization. In conclusion, cocultured os-ADSCs and endo-ADSCs at the ratio of 1:1 showed strong osteogenic and angiogenic differentiation. There is a great potential for osteogenesis and vascularization by 3D culturing cells in a 1:1 ratio in self-assembling peptide RADA16-I scaffolds, which requires evaluation for bone regeneration in vivo.


Assuntos
Tecido Adiposo/citologia , Regeneração Óssea/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Peptídeos/farmacologia , Células-Tronco/citologia , Animais , Biomarcadores/metabolismo , Diferenciação Celular/genética , Proliferação de Células/efeitos dos fármacos , Técnicas de Cocultura , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Neovascularização Fisiológica/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Fenótipo , Ratos Sprague-Dawley , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Células-Tronco/ultraestrutura , Tecidos Suporte/química
13.
J Acoust Soc Am ; 143(1): 202, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29390771

RESUMO

Palatal defect is a common maxillofacial defect after maxillectomy that can be repaired by obturator prostheses, which can effectively improve patients' speech. However, comprehensive evaluation methods for speech recovery are still controversial and remain undefined. A prospective cohort study on 34 patients with palatal defect and 34 healthy controls was performed. Patients received obturator prostheses and their speech was recorded without and then with obturators. Participants pronounced six Chinese vowels and 100 syllables for recording. This paper evaluated the recovery of speech function of patients through the combination of subjective and objective assessment methods. Recruited listeners evaluated the speech intelligibility (SI) of 100 syllables. Vowel formant frequency and quantified vowel nasalization were measured using analysis software. The SI of patients improved significantly after wearing obturators. F2 values of six vowels in patients with obturators were higher than patients without obturators and close to the corresponding values in normal controls. The differences in F2 of /i/ and /u/, (A1-P1) of /i/ and /u/ for patients without and with obturator use were significant. Patients' ability to control the pronunciation of /i/ and /u/ improved greatly with obturators. These provide clinical evidence of the treatment outcomes in patients with palatal defect who received obturators.

14.
Sci Rep ; 7(1): 12688, 2017 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-28978938

RESUMO

Here we introduce lattice defects in WTe2 by Ga+ implantation (GI), and study the effects of defects on the transport properties and electronic structures of the samples. Theoretical calculation shows that Te Frenkel defects is the dominant defect type, and Raman characterization results agree with this. Electrical transport measurements show that, after GI, significant changes are observed in magnetoresistance and Hall resistance. The classical two-band model analysis shows that both electron and hole concentration are significantly reduced. According to the calculated results, ion implantation leads to significant changes in the band structure and the Fermi surface of the WTe2. Our results indicate that defect engineering is an effective route of controlling the electronic properties of WTe2 devices.

15.
J Phys Chem Lett ; 8(12): 2719-2724, 2017 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-28581754

RESUMO

The anisotropic exciton behavior in two-dimensional materials induced by spin-orbit coupling or anisotropic spatial confinement has been exploited in imaging applications. Herein, we propose a new strategy to generate high-energy and robust anisotropic excitons in few-layer ReS2 nanosheets by phase engineering. This approach overcomes the limitation imposed by the layer thickness, enabling production of visible polarized photoluminescence at room temperature. Ultrasonic chemical exfoliation is implemented to introduce the metallic T phase of ReS2 into the few-layer semiconducting Td nanosheets. In this configuration, light excitation can readily produce "hot" electrons to tunnel to the Td phase via the metal-semiconductor interface to enhance the overlap between the wave functions and screened Coulomb interactions. Owing to the strong electron-hole interaction, significant increase in the optical band gap is observed. Highly anisotropic and tightly bound excitons with visible light emission (1.5-2.25 eV) are produced and can be controlled by tailoring the T phase concentration. This novel strategy allows manipulation of polarized optical information and has great potential in optoelectronic devices.

16.
Colloids Surf B Biointerfaces ; 154: 287-296, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28351801

RESUMO

Oral chemotherapy is the preferred route for cancer treatment because it can improve the efficacy and decrease the side effects. Unfortunately, most anticancer drugs suffered from their poor oral bioavailability. Herein, we construct a novel pH-triggered oral drug delivery system by capping of mesoporous silica SBA-15 with pH-responsive polymer poly (acrylic acid) (PAA) via a facile graft-onto strategy. The experiment results demonstrated that the PAA brushes were anchored on the pore outlets of mesoporous silica SBA-15, which can be acted as the gatekeeper to control the drug molecules transport in and out of the pore channels. The PAA capped mesoporous SBA-15 (PAA/SBA-15) exhibited a high drug loading capacity (785.7mg/g), excellent pH-sensitivity and good biocompatibility. In gastric environment (pH=2.0), the drug doxorubicin (DOX) molecules were encapsulated in the pore channels because the pore outlets were capped with collapsed PAA. In contrast, in colonic environment (pH=7.6), it exhibited a fast release because of the removal of capping. In addition, the water solubility of DOX in colonic environment was enhanced after DOX being loaded into the pores of PAA/SBA-15. This pH-triggered oral drug delivery system has promising applications for treatment of colon cancer and other colon diseases.


Assuntos
Resinas Acrílicas/química , Antibióticos Antineoplásicos/metabolismo , Doxorrubicina/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/química , Dióxido de Silício/química , Administração Oral , Antibióticos Antineoplásicos/química , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Doxorrubicina/química , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos , Humanos , Concentração de Íons de Hidrogênio , Cinética , Células-Tronco Mesenquimais , Nanopartículas/administração & dosagem , Nanopartículas/ultraestrutura , Porosidade
17.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 34(3): 388-393, 2017 Jun 01.
Artigo em Chinês | MEDLINE | ID: mdl-29745504

RESUMO

The purpose of this study is to investigate the effects of self-assembling peptide GFS-4 on three-dimen-sional myocardial cell culture and tissue repair of myocardial infarction. The circular dichroism (CD) spectrum was used to detect secondary structure of GFS-4, and atomic force microscope (AFM) was used to analyze the microstructure of self-assembly. The nanofiber scaffolds self-assembled by GFS-4 were used as the three-dimensional culture material to observe the growth effect of cardiomyocytes. The model of myocardial infarction was established and the effect of GFS-4 on myocardial infarction was studied. The results indicated that self-assembling peptide GFS-4 could form mainly ß-sheet structure that can form dense nanofiber scaffolds after 24 hours' self-assembling. The myocardial cells had a favorable growth status in GFS-4 nanofiber scaffold hydrogel when cells treated in three-dimen-sional cell culture. The experiment of repairing myocardial infarction in vitro proved that peptide GFS-4 hydrogel scaffold could alleviate tissue necrosis in a myocardial infarction area. As a new nanofiber scaffold material, self-assembling peptide GFS-4 can be used for three-dimensional cell culture and tissue repairing in myocardial infarction area.

18.
ACS Omega ; 2(6): 2639-2648, 2017 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31457605

RESUMO

To improve the properties of poly(butylene succinate) (PBS), a series of poly[(butylene succinate)-co-poly(tetramethylene glycol)]s (PBSTMGs) with different poly(tetramethylene glycol) (PTMG) contents were successfully prepared by the catalyzed melt polycondensation process. The effect of introducing flexible PTMG segments on the properties was investigated, and they were compared to those of PBS. The differential scanning calorimetry results indicated that the melting temperature, crystallization temperature, and crystallinity of PBSTMG copolymers were slightly lower than those of PBS. Furthermore, these thermal parameters decreased gradually with the increase of PTMG content. Dynamic mechanical analysis showed that there was a significant decline of storage modulus (E') in the overall temperature range of copolymers compared to that of PBS. The incorporation of PTMG did not modify the crystal lattice of PBS according to the wide-angle X-ray diffraction analysis. Because of copolymerization, the size of the spherulites was reduced at high PTMG contents. The soft domain in the copolymers might contribute to the enhanced tear strength of PBSTMG. The elongation at break and impact strength of PBSTMG copolymers were greatly improved as a result of the phase separation structure and lower degree of crystallinity. Especially, when the PTMG content was 10 mol %, the impact strength of the copolymer reached up to 4.5 times that of PBS. In addition, with more soft segments introduced, the biodegradability of the copolymers became much better than that of PBS.

19.
J Am Chem Soc ; 137(35): 11419-24, 2015 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-26302086

RESUMO

Crystalline ß-FeSi2 nanocubes with two {100} facets and four {011} lateral facets synthesized by spontaneous one-step chemical vapor deposition exhibit strong room-temperature ferromagnetism with saturation magnetization of 15 emu/g. The room-temperature ferromagnetism is observed from the ß-FeSi2 nanocubes larger than 150 nm with both the {100} and {011} facets. The ferromagnetism is tentatively explained with a simplified model including both the itinerant electrons in surface states and the local moments on Fe atoms near the surfaces. The work demonstrates the transformation from a nonmagnetic semiconductor to a magnetic one by exposing specific facets and the room-temperature ferromagnetism can be manipulated under light irradiation. The semiconducting ß-FeSi2 nanocubes may have large potential in silicon-based spintronic applications.

20.
Oncol Lett ; 10(5): 3223-3227, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26722316

RESUMO

MicroRNA-34a (miR-34a) functions as a tumor suppressor gene and inhibits abnormal cell growth by regulating the expression of other genes. The role of miR-34a in regulating sirtuin 1 (SIRT1) in prostate cancer remains unclear. The objective of the present study was to investigate the biological function and molecular mechanisms of miR-34a regulation of SIRT1 in human prostate cancer samples and the human prostate cancer cell line, PC-3. Fresh prostate tissues were obtained from patients, and the miR-34a expression in prostate cancer tissues was measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). qPCR and western blotting were performed to assess the effects of miR-34a overexpression on SIRT1 regulation in PC-3 cells, and the cell growth was assessed by Cell Counting Kit-8 (CCK-8). Flow cytometry was used to assess the cell cycle status of the cells. The miR-34a expression levels in prostate cancer tissues were significantly reduced compared with adjacent normal prostate tissues (P<0.05). SIRT1 expression levels in PC-3 cells with over-expression of miR-34a were significantly reduced compared with those in the negative control (P<0.05). The over-expression of miR-34a inhibited PC-3 cells growth and resulted in increased cell cycle arrest compared with the negative control (P<0.05). In conclusion, miR-34a inhibits the human prostate cancer cell proliferation, in part, through the downregulation of SIRT1 expression.

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