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1.
J Am Chem Soc ; 142(12): 5526-5530, 2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32131597

RESUMO

Planar, terpyridine-based metal complexes with the Sierpinski triangular motif and alkylated corners undergo a second self-assembly event to give megastructural Sierpinski pyramids; assembly is driven by the facile lipophilic-lipophilic association of the alkyl moieties and complementary perfect fit of the triangular building blocks. Confirmation of the 3D, pyramidal structures was verified and supported by a combination of TEM, AFM, and multiscale simulation techniques.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32086217

RESUMO

Biological long short-term memory (B-LSTM) can effectively help human process all kinds of received information. In this work, a memristive B-LSTM circuit which mimics a conversion from short-term memory to long-term memory is proposed. That is, the stronger the signal, the more profound the memory and the higher the output. On this basis, an image binarization circuit using adaptive row threshold algorithm is proposed. It can make the image remain a deep impression on the strong pixel information and effectively filter the relatively weak pixel information. In combination with the function of image binarization, a memristive circuit for eyes state detection is proposed by adding corresponding horizontal projection calculation, subtraction calculation and judgement open or closed eyes modules. The proposed circuit can detect whether there is a blink between two adjacent facial images, which uses the characteristics of memristor to detect the difference of horizontal projection between two images. Due to the use of memristor, the proposed circuit can realize in-memory computing, which fundamentally avoids the problem of storage wall and shorten the execution time. Finally, an expectation application in fatigue driving based on the proposed method is demonstrated, which indicates the practicability of the circuit design in this work.

3.
Org Lett ; 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31999462

RESUMO

A novel method of metal-free dehydrogenative silylation of enamides has been developed. The desired functionalized vinylsilane products were obtained in moderate to good yield and with high stereoselectivities. This protocol displays good tolerance of various functionalities. Furthermore, the high chemoselectivity of this reaction enables us to introduce different unsaturated C-C moieties to the products. The ease of further derivatization of the products to other useful compounds also demonstrates the highly synthetic utility of the current methodology.

4.
IEEE Trans Biomed Circuits Syst ; 14(2): 173-185, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31944964

RESUMO

In this work, a memristive circuit with affective multi-associative learning function is proposed, which mimics the process of human affective formation. It mainly contains three modules: affective associative learning, affective formation, affective expression. The first module is composed of several affective single-associative learning circuits consisting of memristive neurons and synapses. Memristive neuron will be activated and output pulses if its input exceeds the threshold. After it is activated, memristive neuron can automatically return to the inactive state. Memristive synapse can realize learning and forgetting functions based on the signals from pre- and post-neurons. The learning rule is pre-neuron activated lags behind post-neuron for a short time; the forgetting rule is to repeatedly activate pre-neuron after the emotion is learned. The process of learning or forgetting corresponds to facilitating or inhibiting synaptic weight, that is, decreasing or increasing memristance continuously. Different voltage signals applied to memristors and different parameters of memristors would lead to different synaptic weights which indicate different affective association. The second module can convert affective signals to corresponding emotions. The formed emotions can be shown in a face by the third module. The simulation results in PSPICE show that the proposed circuit system can learn, forget and form emotions like human. If the proposed circuit is further used on a humanoid robot platform through further research, the robot will have the ability of affective interaction with human so that it can be effectively used in affective company and other aspects.

5.
Nat Commun ; 10(1): 4469, 2019 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-31578337

RESUMO

Magnetic topological insulators (MTIs) offer a combination of topologically nontrivial characteristics and magnetic order and show promise in terms of potentially interesting physical phenomena such as the quantum anomalous Hall (QAH) effect and topological axion insulating states. However, the understanding of their properties and potential applications have been limited due to a lack of suitable candidates for MTIs. Here, we grow two-dimensional single crystals of Mn(SbxBi(1-x))2Te4 bulk and exfoliate them into thin flakes in order to search for intrinsic MTIs. We perform angle-resolved photoemission spectroscopy, low-temperature transport measurements, and first-principles calculations to investigate the band structure, transport properties, and magnetism of this family of materials, as well as the evolution of their topological properties. We find that there exists an optimized MTI zone in the Mn(SbxBi(1-x))2Te4 phase diagram, which could possibly host a high-temperature QAH phase, offering a promising avenue for new device applications.

6.
Org Lett ; 21(15): 6016-6020, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31318220

RESUMO

A copper-catalyzed highly regio- and stereoselective silaboration of alkynes was developed. In this work, direct cis-difunctionalization of alkynes was realized with silaboronate reagent and copper catalyst in aprotic solvents. The regiodivergent silaborations were controlled by tuning the copper catalysts and phosphine ligands used in reactions. This protocol provides an efficient and practical method to synthesize the multisubstituted functionalized alkenes with specific stereoselectivity.

7.
IEEE Trans Biomed Circuits Syst ; 13(4): 631-644, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31217128

RESUMO

Sensory processor in human skin is used for processing and transmitting sensations to the brain, which leads to body actions and emotional responses. In this paper, a memristive circuit of emotional generation and evolution based on skin-like sensory processor is proposed. The circuit includes: first, memristive skin-like sensory processor module; second, emotional generation and evolution module; and third, emotional expression module. The first module consists of four single-memristor skin-like sensory processors, which correspond to process sensations of pain, cold, warm, and tactile. It will automatically return to its initial state if sensory signals disappear. But if sensory signals are much strong, it will not automatically return to initial state unless applied "restoring signal" just like a surgical operation. The second module realizes a conversion mechanism from sensations to emotions using memristor as emotional synapse. Given signals from skin-like sensory processor, the memristance will decrease, which means the extent of emotion will increase, such as more happy. This is the emotional generation. The extent of emotion will be changed if the same sensation is applied to skin-like sensory processor repeatedly, which is the emotional evolution. The third module can show the generated emotions visually. The simulation results in PSPICE show that the proposed circuit can generate and evolve emotions like human beings after processing sensory signals from skin. The proposed circuit can be applied in a perceptual robot platform to realize the conversion from sensations to emotions, enabling the robot to have the ability to sense and process information.


Assuntos
Eletricidade , Emoções , Sensação/fisiologia , Pele/anatomia & histologia , Biomimética , Simulação por Computador , Fontes de Energia Elétrica , Desenho de Equipamento , Humanos , Processamento de Sinais Assistido por Computador
8.
J Mol Cell Biol ; 11(3): 212-223, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30496435

RESUMO

Activation of the tumour suppressor p53 upon cellular stress can induce a number of different cellular processes. The diverse actions of these processes are critical for the protective function of p53 in preventing the development of cancer. However, it is still not fully understood which process(es) activated by p53 is/are critical for tumour suppression and how this might differ depending on the type of cells undergoing neoplastic transformation and the nature of the drivers of oncogenesis. Moreover, it is not clear why upon activation of p53 some cells undergo cell cycle arrest and senescence whereas others die by apoptosis. Here we discuss some of the cellular processes that are crucial for p53-mediated tumour suppression and the factors that could impact cell fate upon p53 activation. Finally, we describe therapies aimed either at activating wild-type p53 or at changing the behaviour of mutant p53 to unleash tumour growth suppressive processes for therapeutic benefit in malignant disease.

9.
Proc Natl Acad Sci U S A ; 115(49): 12359-12364, 2018 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-30455311

RESUMO

Morphogenesis is a phenomenon by which a wide variety of functional organs are formed in biological systems. In plants, morphogenesis is primarily driven by differential growth of tissues. Much effort has been devoted to identifying the role of genetic and biomolecular pathways in regulating cell division and cell expansion and in influencing shape formation in plant organs. However, general principles dictating how differential growth controls the formation of complex 3D shapes in plant leaves and flower petals remain largely unknown. Through quantitative measurements on live plant organs and detailed finite-element simulations, we show how the morphology of a growing leaf is determined by both the maximum value and the spatial distribution of growth strain. With this understanding, we develop a broad scientific framework for a morphological phase diagram that is capable of rationalizing four configurations commonly found in plant organs: twisting, helical twisting, saddle bending, and edge waving. We demonstrate the robustness of these findings and analyses by recourse to synthetic reproduction of all four configurations using controlled polymerization of a hydrogel. Our study points to potential approaches to innovative geometrical design and actuation in such applications as building architecture, soft robotics and flexible electronics.


Assuntos
Flores/crescimento & desenvolvimento , Orchidaceae/crescimento & desenvolvimento , Desenvolvimento Vegetal , Folhas de Planta/crescimento & desenvolvimento , Modelos Biológicos
10.
Nanoscale ; 10(25): 12062-12067, 2018 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-29911217

RESUMO

The interfacial Dzyaloshinskii-Moriya interaction (DMI) in ferromagnetic/heavy metal ultra-thin film structures has attracted a lot of attention thanks to its capability to stabilize Néel-type domain walls (DWs) and magnetic skyrmions for the realization of non-volatile memory and logic devices. In this study, we demonstrate that magnetic properties in perpendicularly magnetized Ta/Pt/Co/MgO/Pt heterostructures, such as magnetization and DMI, can be significantly influenced by the MgO thickness. To avoid the excessive oxidation of Co, an ultrathin Mg layer is inserted to improve the quality of the Co-MgO interface. By using field-driven domain wall expansion in the creep regime, we find that non-monotonic tendencies of the DMI field appear when changing the thickness of MgO. With the insertion of a monatomic Mg layer, the strength of the DMI could reach a high level and saturate. We conjecture that the efficient control of the DMI is a result of subtle changes of both Pt/Co and Co/MgO interfaces, which provides a method to optimize the design of ultra-thin structures achieving skyrmion electronics.

11.
Langmuir ; 34(25): 7497-7502, 2018 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-29847135

RESUMO

Results of the coarse-grained molecular dynamics simulations are used to show that the force balance analysis at the triple-phase contact line formed at an elastic substrate has to include a quartet of forces: three surface tensions (surface free energies) and an elastic force per unit length. In the case of the contact line formed by a droplet on an elastic substrate an elastic force is due to substrate deformation generated by formation of the wetting ridge. The magnitude of this force fel is proportional to the product of the ridge height h and substrate shear modulus G. Similar elastic line force should be included in the force analysis at the triple-phase contact line of a solid particle in contact with an elastic substrate. For this contact problem elastic force obtained from contact angles and surface tensions is a sum of the elastic forces acting from the side of a solid particle and an elastic substrate. By considering only three line forces acting at the triple-phase contact line, one implicitly accounts the bulk stress contribution as a part of the resultant surface stresses. This "contamination" of the surface properties by a bulk contribution could lead to unphysically large values of the surface stresses in soft materials.

12.
ACS Appl Mater Interfaces ; 10(19): 16887-16892, 2018 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-29682962

RESUMO

In this work, we demonstrate that skyrmions can be nucleated in the free layer of a magnetic tunnel junction (MTJ) with Dzyaloshinskii-Moriya interactions (DMIs) by a spin-polarized current with the assistance of stray fields from the pinned layer. The size, stability, and number of created skyrmions can be tuned by either the DMI strength or the stray field distribution. The interaction between the stray field and the DMI effective field is discussed. A device with multilevel tunneling magnetoresistance is proposed, which could pave the ways for skyrmion-MTJ-based multibit storage and artificial neural network computation. Our results may facilitate the efficient nucleation and electrical detection of skyrmions.

13.
Exp Mol Med ; 50(4): 25, 2018 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-29650947

RESUMO

The putative tumor suppressor microRNA let-7c is extensively associated with the biological properties of cancer cells. However, the potential involvement of let-7c in the differentiation of mesenchymal stem cells has not been fully explored. In this study, we investigated the influence of hsa-let-7c (let-7c) on the proliferation and differentiation of human dental pulp-derived mesenchymal stem cells (DPMSCs) treated with insulin-like growth factor 1 (IGF-1) via flow cytometry, CCK-8 assays, alizarin red staining, real-time RT-PCR, and western blotting. In general, the proliferative capabilities and cell viability of DPMSCs were not significantly affected by the overexpression or deletion of let-7c. However, overexpression of let-7c significantly inhibited the expression of IGF-1 receptor (IGF-1R) and downregulated the osteo/odontogenic differentiation of DPMSCs, as indicated by decreased levels of several osteo/odontogenic markers (osteocalcin, osterix, runt-related transcription factor 2, dentin sialophosphoprotein, dentin sialoprotein, alkaline phosphatase, type 1 collagen, and dentin matrix protein 1) in IGF-1-treated DPMSCs. Inversely, deletion of let-7c resulted in increased IGF-1R levels and enhanced osteo/odontogenic differentiation. Furthermore, the ERK, JNK, and P38 MAPK pathways were significantly inhibited following the overexpression of let-7c in DPMSCs. Deletion of let-7c promoted the activation of the JNK and P38 MAPK pathways. Our cumulative findings indicate that Let-7c can inhibit the osteo/odontogenic differentiation of IGF-1-treated DPMSCs by targeting IGF-1R via the JNK/P38 MAPK signaling pathways.


Assuntos
Diferenciação Celular/genética , Polpa Dentária/citologia , Sistema de Sinalização das MAP Quinases , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/genética , Receptores de Somatomedina/genética , Regiões 3' não Traduzidas , Adolescente , Adulto , Biomarcadores , Proliferação de Células , Células Cultivadas , Regulação da Expressão Gênica , Humanos , Modelos Biológicos , Odontogênese/genética , Osteogênese/genética , Fenótipo , Interferência de RNA , Adulto Jovem
14.
ACS Omega ; 3(11): 15426-15434, 2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31458199

RESUMO

The surface relief structure of polymer films over large areas can be controlled by combining nanoscale imprinting and microscale ultraviolet-ozone (UVO) radiation, resulting in hierarchical structured surfaces. First, nanoscale patterns were formed by nanoimprinting elastomer [poly(dimethylsiloxane) (PDMS)] films with a pattern on a digital video disk. Micron-scale patterns were then superimposed on the nanoimprinted PDMS films by exposing them to ultraviolet radiation in oxygen (UVO) through a transmission electron microscopy grid mask having variable microscale patterning. UVO exposure leads to conversion and densification of PDMS to SiO x , leading to micron height relief features that follow a linear scaling relation with pattern dimension. Further, the pattern scopes are shown to collapse into a master curve by normalized feature values. Interestingly, these relief structures preserve the nanoscale features. In this paper, the influence of the self-limiting PDMS densification, wall stress at the boundary of micro-depression, and UVO exposure energy is studied in control of the micro-depression scale. This simple two-step imprinting process involving both nanoimprinting and UV radiation allows for facile fabrication of the dimension adjustable micro-nano hierarchically structures not only on elastomer films but also on thermoplastic polymer films. Coarse-grained molecular dynamics simulations were performed to correlate the surface tension and elastic properties of polymeric materials to the deformation of the pattern structure.

15.
Am J Physiol Lung Cell Mol Physiol ; 314(2): L256-L275, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29074488

RESUMO

Pulmonary vascular remodeling characterized by concentric wall thickening and intraluminal obliteration is a major contributor to the elevated pulmonary vascular resistance in patients with idiopathic pulmonary arterial hypertension (IPAH). Here we report that increased hypoxia-inducible factor 2α (HIF-2α) in lung vascular endothelial cells (LVECs) under normoxic conditions is involved in the development of pulmonary hypertension (PH) by inducing endothelial-to-mesenchymal transition (EndMT), which subsequently results in vascular remodeling and occlusive lesions. We observed significant EndMT and markedly increased expression of SNAI, an inducer of EndMT, in LVECs from patients with IPAH and animals with experimental PH compared with normal controls. LVECs isolated from IPAH patients had a higher level of HIF-2α than that from normal subjects, whereas HIF-1α was upregulated in pulmonary arterial smooth muscle cells (PASMCs) from IPAH patients. The increased HIF-2α level, due to downregulated prolyl hydroxylase domain protein 2 (PHD2), a prolyl hydroxylase that promotes HIF-2α degradation, was involved in enhanced EndMT and upregulated SNAI1/2 in LVECs from patients with IPAH. Moreover, knockdown of HIF-2α (but not HIF-1α) with siRNA decreases both SNAI1 and SNAI2 expression in IPAH-LVECs. Mice with endothelial cell (EC)-specific knockout (KO) of the PHD2 gene, egln1 (egln1EC-/-), developed severe PH under normoxic conditions, whereas Snai1/2 and EndMT were increased in LVECs of egln1EC-/- mice. EC-specific KO of the HIF-2α gene, hif2a, prevented mice from developing hypoxia-induced PH, whereas EC-specific deletion of the HIF-1α gene, hif1a, or smooth muscle cell (SMC)-specific deletion of hif2a, negligibly affected the development of PH. Also, exposure to hypoxia for 48-72 h increased protein level of HIF-1α in normal human PASMCs and HIF-2α in normal human LVECs. These data indicate that increased HIF-2α in LVECs plays a pathogenic role in the development of severe PH by upregulating SNAI1/2, inducing EndMT, and causing obliterative pulmonary vascular lesions and vascular remodeling.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Células Endoteliais/patologia , Transição Epitelial-Mesenquimal , Hipertensão Pulmonar/etiologia , Prolina Dioxigenases do Fator Induzível por Hipóxia/fisiologia , Animais , Células Cultivadas , Células Endoteliais/metabolismo , Hipertensão Pulmonar/metabolismo , Hipertensão Pulmonar/patologia , Hipóxia/fisiopatologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miócitos de Músculo Liso/metabolismo , Miócitos de Músculo Liso/patologia , Fatores de Transcrição da Família Snail/genética , Fatores de Transcrição da Família Snail/metabolismo , Remodelação Vascular
16.
J Cell Physiol ; 233(3): 2386-2397, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28749049

RESUMO

Mineral trioxide aggregate (MTA), as a bioactive material, has a widespread application in clinical practice. To date, the effects of MTA on the proliferation and differentiation of human periodontal ligament stem cells (hPDLSCs) remain unclear. hPDLSCs were isolated from human periodontal ligament tissues and cultured with MTA conditioned media. Cell counting kit-8 (CCK-8) assay was performed to assess the proliferation capacity of MTA-treated hPDLSCs. Immunofluorescence assay, alkaline phosphatase (ALP) activity, alizarin red staining, real-time RT-PCR, and western blot analyses were used to investigate the odonto/osteogenic capacity of hPDLSCs as well as the involvement of NF-κB and MAPK pathways. ALP activity assay revealed that 2 mg/ml was the optimal concentration for the induction of hPDLSCs by MTA. The protein expression of DSP, RUNX2, OCN, OSX, OPN, DMP1, ALP, and COL-I in MTA-treated hPDLSCs was significantly higher than those in control group (p < 0.01). When hPDLSCs were treated with the inhibitors of NF-κB and MAPK pathways (U0126, SP600125, SB203580, and BMS345541), the effects of MTA on the differentiation of hPDLSCs were suppressed. Mechanistically, P65 was detected to transfer from cytoplasm to nuclei, as indicated by western blot and immunofluorescence assay. Moreover, MAPK-related proteins and its downstream transcription factors were also upregulated in MTA-treated hPDLSCs. Together, mineral trioxide aggregate can promote the odonto/osteogenic capacity of hPDLSCs via activating the NF-κB and MAPK pathways.


Assuntos
Compostos de Alumínio/farmacologia , Compostos de Cálcio/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , NF-kappa B/metabolismo , Osteogênese/efeitos dos fármacos , Óxidos/farmacologia , Ligamento Periodontal/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Silicatos/farmacologia , Células-Tronco/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Regulação da Expressão Gênica , Humanos , Ligamento Periodontal/enzimologia , Células-Tronco/enzimologia , Fatores de Tempo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
17.
Environ Sci Pollut Res Int ; 24(15): 13741-13748, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28401388

RESUMO

Heavy metal concentrations in soil, wheat, and scalp hair exposed to Beijing sewage discharge channel sewage irrigation area (BSIA) in Tianjin were studied to evaluate the influence of sewage irrigation. Results showed that the continuous application of wastewater has led to an accumulation of heavy metals in the soil, with 55.2 and 8.62% of soil samples accumulating Cd and Zn, respectively, at concentrations exceeding the permissible limits in China. Concentrations of heavy metals in wheat grain from BSIA were higher than these from the clean water irrigation area by 63.2% for Cd, 3.8% for Cu, 100% for Pb, 6.6% for Zn, and 326.7% for Cr. The heavy metal bioaccumulation factor (BAF) of wheat/soil in BSIA showed the following order: Zn > Cd > Cu > Pb > Cr. Interestingly, these accumulation of heavy metals in soil after sewage irrigation could increase the migration ability of heavy metals (particularly Zn and Cd) from soil to wheat. Mean concentrations of heavy metals in the hair of residents followed the decreasing trend of Zn > Cu > Pb > Cr > Cd, which were higher than the control area by 110.0% for Cd, 20.0% for Cu, 55.9% for Zn, 36.6% for Pb, and 64.6% for Cr. Concentrations of heavy metals in male human hair in BSIA were higher than those of females. And the concentrations of heavy metals except for Pb in human hair increased with their increasing ages. The heavy metal BAF values of wheat/soil in BSIA showed the trend of Zn (98.0057) > Pb (7.0162) > Cr (5.5788) > Cu (5.4853) > Cd (3.5584); heavy metals had obvious biological amplification from wheat to human hair. These results indicated that local population health was potentially exposed to the heavy metal risk via wheat consumption.


Assuntos
Esgotos , Poluentes do Solo , Pequim , China , Monitoramento Ambiental , Humanos , Metais Pesados , Couro Cabeludo/química , Solo
18.
Sci Rep ; 6: 36922, 2016 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-27833148

RESUMO

Insulin-like growth factor-1 (IGF-1) and its receptor IGF-1R play a paramount role in tooth/bone formation while hsa-let-7c actively participates in the osteogenic differentiation of mesenchymal stem cells. However, the interaction between IGF-1/IGF-1R and hsa-let-7c on the committed differentiation of stem cells from apical papilla (SCAPs) remains unclear. In this study, human SCAPs were isolated and treated with IGF-1 and hsa-let-7c over/low-expression viruses. The odonto/osteogenic differentiation of these stem cells and the involvement of mitogen-activated protein kinase (MAPK) pathway were subsequently investigated. Alizarin red staining showed that hsa-let-7c low-expression can significantly promote the mineralization of IGF-1 treated SCAPs, while hsa-let-7c over-expression can decrease the calcium deposition of IGF-1 treated SCAPs. Western blot assay and real-time reverse transcription polymerase chain reaction further demonstrated that the expression of odonto/osteogenic markers (ALP, RUNX2/RUNX2, OSX/OSX, OCN/OCN, COL-I/COL-I, DSPP/DSP, and DMP-1/DMP-1) in IGF-1 treated SCAPs were significantly upregulated in Let-7c-low group. On the contrary, hsa-let-7c over-expression could downregulate the expression of these odonto/osteogenic markers. Moreover, western blot assay showed that the JNK and p38 MAPK signaling pathways were activated in Let-7c-low SCAPs but inhibited in Let-7c-over SCAPs. Together, the IGF-1/IGF-1R/hsa-let-7c axis can control the odonto/osteogenic differentiation of IGF-1-treated SCAPs via the regulation of JNK and p38 MAPK signaling pathways.


Assuntos
Papila Dentária/citologia , Fator de Crescimento Insulin-Like I/genética , MicroRNAs/genética , Receptores de Somatomedina/genética , Células-Tronco/citologia , Adolescente , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Papila Dentária/metabolismo , Humanos , Fator de Crescimento Insulin-Like I/metabolismo , Sistema de Sinalização das MAP Quinases , Odontogênese , Osteogênese , Receptores de Somatomedina/metabolismo , Células-Tronco/metabolismo , Adulto Jovem
19.
Oncotarget ; 7(5): 6048-62, 2016 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-26755661

RESUMO

Semaphorin3A (SEMA3A), an axon guidance molecule in the nervous system, plays an inhibitory role in oncogenesis. Here, we investigated the expression pattern and biological roles of SEMA3A in head and neck squamous cell carcinoma (HNSCC) by gain-of-function assays using adenovirus transfection and recombinant human SEMA3A protein. In addition, we explored the therapeutic efficacy of SEMA3A against HNSCC in vivo. We found that lower expression of SEMA3A correlated with shorter overall survival and had independent prognostic importance in patients with HNSCC. Both genetic and recombinant SEMA3A protein inhibited cell proliferation and colony formation and induced apoptosis, accompanied by decreased cyclin E, cyclin D, CDK2, CDK4 and CDK6 and increased P21, P27, activated caspase-5 and caspase-7. Moreover, over-expression of SEMA3A suppressed migration, invasion and epithelial-to-mesenchymal transition due in part to the inhibition of NF-κB and SNAI2 in HNSCC cell lines. Furthermore, intratumoral SEMA3A delivery significantly stagnated tumor growth in a xenograft model. Taken together, our results indicate that SEMA3A serves as a tumor suppressor during HNSCC tumorigenesis and a new target for the treatment of HNSCC.


Assuntos
Carcinoma de Células Escamosas/terapia , Neoplasias de Cabeça e Pescoço/terapia , Semaforina-3A/biossíntese , Animais , Orientação de Axônios , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Feminino , Genes Supressores de Tumor , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Distribuição Aleatória , Semaforina-3A/administração & dosagem , Semaforina-3A/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço , Análise de Sobrevida , Transfecção , Ensaios Antitumorais Modelo de Xenoenxerto
20.
Huan Jing Ke Xue ; 37(9): 3423-3429, 2016 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-29964776

RESUMO

Yuqiao Reservoir, an important adjusting reservoir in the project of diverting water from the Luanhe River to Tianjin City, is an important water resource for Tianjin City. Concentrations and spatial variation characteristics of Cd, As, Pb, Cu, Cr, and Zn from 33 sub watershed sampling sites of Yuqiao reservoir and the relationship to landscape pattern were discussed. The result showed that average concentrations of Cd, As, Cu, Cr in suspended particulate matter were higher than Chinese environmental quality standard Grade one for soils, and there were ecological risks for them because they could arrive at Yuqiao reservoir. The average concentrations of Cd, As, Pb, Cu, Cr, and Zn in surface sediments were 0.32 mg·kg-1, 30.39 mg·kg-1, 33.49 mg·kg-1, 58.20 mg·kg-1, 90.16 mg·kg-1 and 94.80 mg·kg-1 respectively. The average concentrations of Cd, As, Cu and the concentrations of Pb, Cr, Zn in partial samples exceeded Chinese environmental quality standard Grade one for soils. The average concentrations of Cd, Cr, Zn in surface sediments of three tributaries increased in the order of Linhe River >Shahe River >Lihe Rier, Cu decreased in the order of Linhe River < Shahe River < Lihe River, and As, Pb increased in the order of Shahe River >Linhe River >Lihe Ricer. Land use types in Yuqiao reservoir basin had some impact on the distribution of heavy metal concentrations in river surface sediments. Woodland and shrub grass land determined the natural distribution trend of heavy metals in surface sediments. Gardenland and industrial & mining land usage had impact on Cd, As, Pb, Cr distributions. Farmland and village & town land usage did not produce negative influence on heavy metal distribution.

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