Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 44
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Viruses ; 11(11)2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31717393

RESUMO

The prevalence and variation of the H9N2 avian influenza virus (AIV) pose a threat to public health. A total of eight viruses isolated from farmed poultry in South China during 2017-2018 were selected as representative strains for further systematic study. Phylogenetic analyses indicated that these prevalent viruses belong to the Y280-like lineage and that the internal genes are highly similar to those of recently circulating human H7N9 viruses. The receptor-binding assay showed that most of the H9N2 isolates preferentially bound to the human-like receptor, increasing the risk of them crossing the species barrier and causing human infection. Our in vitro, multi-step growth curve results indicate these viruses can effectively replicate in mammalian cells. Infection in mice showed that three viruses effectively replicated in the lung of mice. Infection in swine revealed that the viruses readily replicated in the upper respiratory tract of pig and effectively induced viral shedding. Our findings suggested that the H9N2 AIVs circulating in poultry recently acquired an enhanced ability to transmit from avian to mammalians, including humans. Based on our findings, we propose that it is essential to strengthen the efforts to surveil and test the pathogenicity of H9N2 AIVs.

2.
Chemphyschem ; 2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31769199

RESUMO

Organic semiconductor (OSC) crystals have great potential to be applied in many fields, as they can be flexibly designed according to the demands and show an outstanding device performance. However, OSCs with the capacity of solid state crystallization (SSC) are developing too slowly to meet demands in productions and applications, due to their difficulties in molecular design and synthesis, unclear mechanism and high dependence on experimental conditions. In this work, in order to solve the problems, we synthesized an organic semiconductor capable of SSC at room temperature by adjusting the relationship between conjugated groups and functional groups. The thermodynamic and kinetic properties have been studied to discover the model of film SSC. Moreover, it can be purposefully controlled to prepare the high-quality crystals, and their corresponding organic electronic devices were further fabricated and discussed.

3.
Materials (Basel) ; 12(22)2019 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-31744241

RESUMO

High-viscosity modified asphalt is mainly used as a binder for porous asphalt in China and Japan. In order to meet the demand for using porous asphalt under high temperature condition in Africa, high-viscosity asphalt made from low-grade matrix asphalt, which is commonly used in Africa is investigated. Based on simulation of local climate in Africa, the suitable range of high viscosity additive content for different matrix asphalt was obtained by analyzing dynamic viscosity of the asphalt. Through PG high temperature grading, multi-stress repeated creep, accelerated fatigue, temperature sweep and other tests, changes of high temperature, anti-fatigue and anti-shear indicators before and after modification were compared and analyzed and effects of different matrix asphalt were also studied. Finally, considering engineering requirements, mixing and compaction temperatures of various high-viscosity modified asphalt were determined through study of viscosity-temperature characteristics. This research provides a support for preparation of high-viscosity modified asphalt and porous asphalt mixture by using low grade asphalt. The research achievements can help to guide the material design and application of porous asphalt in Africa and other high temperature areas.

4.
Nat Commun ; 10(1): 3872, 2019 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-31455804

RESUMO

Molecular self-assembly into crystallised films or wires on surfaces produces a big family of motifs exhibiting unique optoelectronic properties. However, little attention has been paid to the fundamental mechanism of molecular crystallisation. Here we report a biomimetic design of phosphonate engineered, amphiphilic organic semiconductors capable of self-assembly, which enables us to use real-time in-situ scanning probe microscopy to monitor the growth trajectories of such organic semiconducting films as they nucleate and crystallise from amorphous solid states. The single-crystal film grows through an evolutionary selection approach in a two-dimensional geometry, with five distinct steps: droplet flattening, film coalescence, spinodal decomposition, Ostwald ripening, and self-reorganised layer growth. These sophisticated processes afford ultralong high-density microwire arrays with high mobilities, thus promoting deep understanding of the mechanism as well as offering important insights into the design and development of functional high-performance organic optoelectronic materials and devices through molecular and crystal engineering.

5.
Spectrochim Acta A Mol Biomol Spectrosc ; 219: 427-435, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31063957

RESUMO

Whole blood viscosity (WBV) is a group of important clinical indicators of cardio-cerebral vascular diseases. Existing detection methods for WBV are complex, making them inconvenient for large population screening. Blood viscosity is closely related to the deformability and aggregation of erythrocytes, which are associated with haemoglobin. Haemoglobin has obvious near-infrared (NIR) spectral absorption. Scattering occurs when NIR light enters a viscous blood sample, and its scattering degree is correlated with blood viscosity. Based on repeated spectral measurements and spectral similarity, spectral noise-to-signal ratio (NSR) was proposed to quantify the spectral scattering effect in the blood sample. A novel selection method of piecewise-continuous wavelengths, named NSR priority-partial least squares (NSRP-PLS), was proposed and applied for visible-NIR quantitative analysis of WBV with high, medium and low shear rates [WBV(H), WBV(M), WBV(L)]. Modelling was separately performed by gender to allow for systematic gender differences in blood viscosity. For the NIR-predicted and clinically measured values of the three WBV indicators in independent validation, the root mean square errors for prediction (SEP) were 0.498, 0.222 and 0.193 (mPa·s), respectively. And the correlation coefficients (RP) were 0.927, 0.934 and 0.927, respectively. Compared with the three current well-performing methods (MW-PLS, CARS-PLS and SPA-PLS), the proposed NSRP-PLS method achieved better predictive accuracy. Results indicated that visible-NIR spectroscopy combined with the NSRP-PLS method can be used for the quantitative analysis of WBV. The proposed analytical method is rapid, reagent-free and is scientific and meaningful for cardio-cerebral vascular diseases screening in large populations.


Assuntos
Viscosidade Sanguínea , Algoritmos , Feminino , Humanos , Análise dos Mínimos Quadrados , Masculino , Razão Sinal-Ruído , Espectroscopia de Luz Próxima ao Infravermelho/métodos
6.
Spectrochim Acta A Mol Biomol Spectrosc ; 219: 179-185, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31035128

RESUMO

The rapid and non-destructive discriminant analysis of rice seeds has great significance for large-scale agriculture. Using near-infrared (NIR) diffuse-reflectance spectroscopy with partial least squares-discriminant analysis (PLS-DA), a variety identification method of multi-grain rice seeds was developed. The equidistant combination method was adopted for large-range wavelength screening. A step-by-step phase-out method was proposed to eliminate interference wavelengths and improve the predicted effect. The optimal wavelength model was a combination of 54 wavelengths within 808-974 nm of the short-NIR region. One type of pure rice variety (Y Liangyou 900) was used for identification (negative). Positive samples included the other four pure varieties and contamination of Y Liangyou 900 by the above four varieties. The recognition-accuracy rates for positive, negative and total validation samples reached 93.1%, 95.1%, and 94.3%, respectively. In the long-NIR region, the local optimal wavelength model was a combination of 49 wavelengths within 1188-1650 nm, and the recognition-accuracy rates for positive, negative and total validation samples were 90.3%, 94.1%, and 92.5%, respectively. Results confirmed the feasibility of NIR spectroscopy for variety identification of multi-grain rice seeds. The proposed two discrete-wavelength models located in the short- and long-NIR regions can provide valuable reference to a dedicated spectrometer.


Assuntos
Oryza/química , Sementes/química , Análise Discriminante , Grão Comestível/química , Análise dos Mínimos Quadrados , Espectroscopia de Luz Próxima ao Infravermelho/economia , Espectroscopia de Luz Próxima ao Infravermelho/métodos
7.
Pharmacol Res ; 142: 294-302, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30553824

RESUMO

Stress response refers to the systemic nonspecific response upon exposure to strong stimulation or chronic stress, such as severe trauma, shock, infection, burn, major surgery or improper environment, which disturb organisms and damage their physical and psychological health. However, the pathogenesis of stress induced disorder remains complicated and diverse under different stress exposure. Recently, studies have revealed a specific role of microRNAs (miRNAs) in regulating cellular function under different types of stress, suggesting a significant role in the treatment and prevention of stress-related diseases, such as stress ulcer, posttraumatic stress disorder, stress-induced cardiomyopathy and so on. This paper have reviewed the literature on microRNA related stress diseases in different databases including PubMed, Web of Science, and the MiRbase. It considers only peer-reviewed papers published in English between 2004 and 2018. This review summarizes new advances in principles and mechanisms of miRNAs regulating stress signalling pathway and the role of miRNAs in human stress diseases. This comprehensive review is to provide an integrated account of how different stresses affect miRNAs and how stress-miRNA pathways may, in turn, be linked with disease, which offers some potential strategies for stress disorder treatment. Furthermore, the limitation of current studies and challenges for clinical use are discussed.

8.
Org Lett ; 20(20): 6490-6493, 2018 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-30284837

RESUMO

A direct C(sp2)-H thiolation of aromatic amides with disulfides was developed. The coupling reaction proceeds between the thioether radical and cobaltacycle intermediate. This method exhibits a relatively broad substrate scope and high functional group compatibility. A mechanistic study indicates that the cobalt(IV) intermediate is probably formed during the course of the reaction. The thiolation product can be transformed to Quetiapine, which is an atypical antipsychotic agent approved for the treatment of schizophrenia and bipolar disorder.

9.
Angew Chem Int Ed Engl ; 57(43): 14026-14031, 2018 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-30215882

RESUMO

Achieving gate control with atomic precision, which is crucial to the transistor performance on the smallest scale, remains a challenge. Herein we report a new class of aromatic-ring molecular nanotransistors based on graphene-molecule-graphene single-molecule junctions by using an ionic-liquid gate. Experimental phenomena and theoretical calculations confirm that this ionic-liquid gate can effectively modulate the alignment between molecular frontier orbitals and the Fermi energy level of graphene electrodes, thus tuning the charge-transport properties of the junctions. In addition, with a small gate voltage (|VG |≤1.5 V) ambipolar charge transport in electrochemically inactive molecular systems (EG >3.5 eV) is realized. These results offer a useful way to build high-performance single-molecule transistors, thus promoting the prospects for molecularly engineered electronic devices.

10.
Materials (Basel) ; 11(8)2018 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-30087291

RESUMO

This study investigated the effect of seven healing agents on crack healing ability of long-term aged asphalt and its mortar. Different healing agents including sunflower oil, aromatic oil, bitumen emulsion, and maltene-based emulsions were used. The crack healing of asphalt made use of two asphalt disk samples and healing was evaluated using direct tensile tests. For asphalt mortar, notched semi-circular samples were used. Test results indicated that the crack healing of asphalt and its mortar depended strongly on the type of healing agent. In general, asphalt healed faster than its mortar. Asphalt healing could be well improved by using oil agents, while asphalt mortar could be well healed with maltene-based emulsions. The crack healing of asphalt mortar developed rapidly followed by a steady state of increase. Initial crack healing using healing agents could be contributed by the diffusion and softening effects, which resulted in low strength recovery. Long term healing could lead to the bonding reconstitution in the cracks, which were decisive for the final strength gain. The promising healing agent should be able to achieve maximum strength recovery to resist cracking as well as a sufficient re-healing ability to deal with crack opening and closing.

11.
J Vet Res ; 62(1): 7-15, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29978122

RESUMO

Introduction: Classical swine fever (CSF) has caused severe economic losses in pig production in many countries. Recent CSF outbreaks in China are mainly associated with sub-genotype 2.1 of CSF virus (CSFV). Although there is abundant information regarding 2.1 isolates, few data are available on whole-genome analysis. Material and Methods: The biological and genome characteristics of three recently emerged Chinese CSFV isolates, i.e. SD2014-1, SD2014-2, and SD2014-3, were fully analysed. Results: Sequence analysis showed that the isolates shared 83.4%-95.0% nucleotide identity with eight other CSFV isolates. In addition, the 5' untranslated region (5'UTR) and the non-structural (NS) proteins NS3, NS4A, and NS4B were more conserved than other regions of the genome. Phylogenetic analysis based on the complete genome sequences or full-length structural protein E2 gene sequences revealed that the three isolates belonged to sub-genotype 2.1b. In addition, several unique molecular characteristics of the 5'UTR, 3'UTR, and E2 were identified. Conclusion: The genomic variations of the three isolates will support further analysis of virulence determinants and the evolutionary trend of CSFV.

12.
Materials (Basel) ; 11(6)2018 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-29932097

RESUMO

Asphalt pavement is widely used for expressways due to its advantages of flexibility, low cost, and easy maintenance. However, pavement failures, including cracking, raveling, and potholes, will appear after long-term service. This research evaluated the residual fatigue properties of asphalt pavement after long-term field service. Fatigue behavior of specimens with different pavement failure types, traffic load, service time, and layers were collected and characterized. Results indicate that after long-term field service, surface layer has a longer fatigue life under small stress levels, but shorter fatigue life under large stress levels. Longer service time results in greater sensitivity to loading stress, while heavier traffic results in shorter fatigue life. Surface and underneath layers present very close fatigue trend lines in some areas, indicating that the fatigue behavior of asphalt mixture in surface and underneath layers are aged to the same extent after eight to ten years of field service.

13.
Exp Ther Med ; 16(1): 265-269, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29896248

RESUMO

The purpose of this study was to explore the correlation of insulin resistance (IR) and leptin with inflammatory factors and vascular endothelial injury in patients with type 2 diabetes mellitus (T2DM) complicated with coronary heart disease (CHD) was explored. One hundred and fifty normal patients (normal group), 150 patients with pure T2DM (T2DM group) and 150 patients with T2DM complicated with coronary heart disease (T2DM + CHD group) were selected from Xi'an No. 5 Hospital. All the participants met our inclusion criteria. Age, body mass index, waist-to-hip ratio, blood lipid and fasting plasma glucose (FPG), of all the subjects were measured. Chemiluminescent immunoassay was adopted for the detection of FPG and double-antibody sandwich method was used for the determination of fasting plasma leptin, and assay of high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Insulin resistance index (IRI) was used to evaluate IR and enzyme-linked immunosorbent assay was adopted for the detection of von Willebrand factor (vWF) and endothelin (ET-1). Compared with the control group, patients in the T2DM + CHD group and those in the T2DM group had higher homeostasis model assessment-IR, and higher assay of plasma leptin, hs-CRP, IL-6 and TNF-α (P<0.05), and lower vascular endothelial function (P<0.05). Moreover, compared with the T2DM group, T2DM + CHD group had higher plasma leptin, and higher assay of hs-CRP, IL-6 and TNF-α (P<0.05). IRI was positively correlated with hs-CRP (r=0.521, P=0.001), IL-6 (r=0.359, P=0.001) and TNF-α (r=0.386, P=0.001), leptin was positively correlated with hs-CRP (r=0.305, P=0.001), IL-6 (r=0.259, P=0.002) and TNF-α (r=0.429, P=0.001), and IRI had no correlation with ET-1 (r=0.058, P=0.734) and vWF (r=0.047, P=0.812), that is, it had no direct correlation with vascular endothelial function. Level of leptin was positively correlated with ET-1 (r=0.366, P=0.001) and vWF (r=0.471, P=0.001), that is, it was negatively correlated with vascular endothelial function. Our results showed that leptin, hs-CRP, IL-6 and TNF-α are involved in the occurrence and development of CHD in patients with T2DM. IR has no direct correlation with the occurrence and development of CHD in patients with T2DM.

14.
Angew Chem Int Ed Engl ; 57(22): 6512-6516, 2018 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-29517160

RESUMO

A cobalt-catalyzed chelation-assisted tandem C-H activation/C-C cleavage/C-H cyclization of aromatic amides with alkylidenecyclopropanes is reported. This process allows the sequential formation of two C-C bonds, which is in sharp contrast to previous reports on using rhodium catalysts for the formation of C-N bonds. Here the inexpensive catalyst system exhibits good functional-group compatibility and relatively broad substrate scope. The desired products can be easily transformed into polycyclic lactones with m-CPBA. Mechanistic studies revealed that the tandem reaction proceeds through a C-H cobaltation, ß-carbon elimination, and intramolecular C-H cobaltation sequence.

15.
Ultrasonics ; 82: 171-177, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28858778

RESUMO

The appropriate mode pairs of primary and double-frequency circumferential guided waves (CGWs) have been investigated and selected for generation of the cumulative second harmonics, which are applicable for quantitative assessment of damage/degradation in a circular tube. The selection criteria follow the requirements: the higher efficiency of cumulative second-harmonic generation (SHG) of primary CGW propagation, and the larger response sensitivity of cumulative SHG to material damage/degradation [characterized by variation in the third-order elastic (TOE) constants]. The acoustic nonlinearity parameter ß of CGW propagation and the change rate of normalized ß versus the TOE constants of tube material are, respectively, used to describe the efficiency of SHG and its response sensitivity to damage/degradation. Based on the selection criteria proposed, all the possible mode pairs of primary and double-frequency CGWs satisfying the phase velocity matching have been numerically examined. It has been found that there are indeed some mode pairs of CGW propagation with the larger values both of ß and the change rate of normalized ß versus the TOE constants. The CGW mode pairs found in this paper are of practical significance for quantitative assessment of damage/degradation in the circular tube.

16.
Chemosphere ; 190: 154-165, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28987404

RESUMO

Cadmium (Cd) is a detrimental environmental pollutant. Duckweeds have been considered promising candidates for Cd phytoremediation. Although many physiological studies have been conducted, the molecular mechanisms underlying Cd hyperaccumulation in duckweeds are largely unknown. In this study, clone 6001 of Landoltia punctata, which showed high Cd tolerance, was obtained by large-scale screening of over 200 duckweed clones. Subsequently, its growth, Cd flux, Cd accumulation, and Cd distribution characteristics were investigated. To further explore the global molecular mechanism, a comprehensive transcriptome analysis was performed. For RNA-Seq, samples were treated with 20 µM CdCl2 for 0, 1, 3, and 6 days. In total, 9,461, 9,847, and 9615 differentially expressed unigenes (DEGs) were discovered between Cd-treated and control (0 day) samples. DEG clustering and enrichment analysis identified several biological processes for coping with Cd stress. Genes involved in DNA repair acted as an early response to Cd, while RNA and protein metabolism would be likely to respond as well. Furthermore, the carbohydrate metabolic flux tended to be modulated in response to Cd stress, and upregulated genes involved in sulfur and ROS metabolism might cause high Cd tolerance. Vacuolar sequestration most likely played an important role in Cd detoxification in L. punctata 6001. These novel findings provided important clues for molecular assisted screening and breeding of Cd hyperaccumulating cultivars for phytoremediation.


Assuntos
Araceae/efeitos dos fármacos , Araceae/genética , Biodegradação Ambiental , Cádmio/farmacocinética , Perfilação da Expressão Gênica , Araceae/metabolismo , Cádmio/metabolismo , Tolerância a Medicamentos/genética , Perfilação da Expressão Gênica/métodos , Genes de Plantas/efeitos dos fármacos , Genes de Plantas/genética , Análise de Sequência de RNA , Estresse Fisiológico/genética , Transcriptoma/efeitos dos fármacos
17.
Virol J ; 14(1): 159, 2017 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-28830563

RESUMO

BACKGROUND: Currently, porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most economically important viral pathogens in swine in most countries, especially China. Two PRRSV attenuated live vaccine strains (HuN4-F112 and CH-1R) are currently widely used in China. Our previous study showed that HuN4-F112, but not CH-1R, induced high anti-nucleocapsid (N) antibody and neutralizing antibody (NA) titers. Additionally, sera from HuN4-F112 inoculated pigs induced low cross neutralization of CH-1R. METHODS: In the present study, 6 chimeric viruses through exchanging 5' untranslated region (UTR) + open reading frame (ORF)1a, ORF1b, and ORF2-7 + 3'UTR between HuN4-F112 and CH-1R were constructed and rescued based on the infectious clones of rHuN4-F112 and rCH-1R. The characteristics of these viruses were investigated in vitro and vivo. RESULTS: All the three fragments, 5'UTR + ORF1a, ORF1b, and ORF2-7 + 3'UTR, could affect the replication efficiencies of rHuN4-F112 and rCH-1R in vitro. Additionally, both 5'UTR + ORF1a and ORF2-7 + 3'UTR affected the anti-N antibody and NA responses targeting rHuN4-F112 and rCH-1R in piglets. CONCLUSIONS: The 5'UTR + ORF1a region of HuN4-F112 played a key role in inducing NAs in piglets. Furthermore, we confirmed for the first time that ORF1a contains a neutralization region. This study provides important information that can be used for further study of the generation of anti-PRRSV NAs.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Fases de Leitura Aberta/imunologia , Síndrome Respiratória e Reprodutiva Suína/imunologia , Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Vacinas Atenuadas/uso terapêutico , Animais , Anticorpos Antivirais/sangue , Sequência de Bases , Linhagem Celular , China , DNA Complementar , DNA Viral , Cinética , Fases de Leitura Aberta/genética , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Vírus da Síndrome Respiratória e Reprodutiva Suína/crescimento & desenvolvimento , Vírus da Síndrome Respiratória e Reprodutiva Suína/patogenicidade , Suínos/imunologia , Vacinação , Vacinas Atenuadas/genética , Vacinas Atenuadas/isolamento & purificação , Vacinas Virais/imunologia , Viremia/virologia
18.
J Phys Chem Lett ; 8(13): 2849-2854, 2017 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-28598631

RESUMO

Exploring the charge transport process in molecular junctions is essential to the development of molecular electronics. Here, we investigate the temperature-dependent charge transport mechanism of carbon electrode-diarylethene single-molecule junctions, which possess photocontrollable molecular orbital energy levels due to reversible photoisomerization of individual diarylethenes between open and closed conformations. Both the experimental results and theoretical calculations consistently demonstrate that the vibronic coupling (thermally activated at the proper temperature) drives the transition of charge transport in the junctions from coherent tunneling to incoherent transport. Due to the subtle electron-phonon coupling effect, incoherent transport in the junctions proves to have different activation energies, depending on the photoswitchable molecular energy levels of two different conformations. These results improve fundamental understanding of charge transport mechanisms in molecular junctions and should lead to the rapid development of functional molecular devices toward practical applications.

19.
PLoS One ; 12(6): e0180211, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28651015

RESUMO

AIMS: Chronic allograft nephropathy is a worldwide issue with the major feature of progressive allograft fibrosis, eventually ending with graft loss. Adenosine has been demonstrated to play an important role in process of fibrosis. Our study aimed to investigate the relationship between adenosine and fibrosis in renal allograft acute rejection in rat. MATERIALS AND METHODS: Wistar rats and SD rats were selected as experimental animals. Our study designed two groups. In the allograft transplantation group, kidneys of Wistar rats were orthotopically transplanted into SD rat recipients, the same species but not genetically identical, to induce acute rejection. Kidney transplantations of SD rats to SD rats which were genetically identical were served as the control. We established rat models and detected a series of indicators. All data were analyzed statistically. P<0.05 was considered statistically significant. RESULTS: Compared with the control group, levels of adenosine increased significantly in the allograft transplantation group, in which acute rejection was induced (P<0.05). Progressive allograft fibrosis as well as collagen deposition were observed. CONCLUSIONS: These findings suggested that level of adenosine was upregulated in acute rejection after kidney allograft transplantation in rat. Acute rejection may promote renal allograft fibrosis via the adenosine signaling pathways.


Assuntos
Adenosina/metabolismo , Rejeição de Enxerto/metabolismo , Rejeição de Enxerto/patologia , Transplante de Rim/efeitos adversos , Doença Aguda , Aloenxertos , Animais , Colágeno/metabolismo , Fibrose , Rejeição de Enxerto/etiologia , Isoenxertos , Rim/metabolismo , Rim/patologia , Ratos , Ratos Sprague-Dawley , Ratos Wistar
20.
Nano Lett ; 17(2): 856-861, 2017 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-28071918

RESUMO

Biphenyl, as the elementary unit of organic functional materials, has been widely used in electronic and optoelectronic devices. However, over decades little has been fundamentally understood regarding how the intramolecular conformation of biphenyl dynamically affects its transport properties at the single-molecule level. Here, we establish the stereoelectronic effect of biphenyl on its electrical conductance based on the platform of graphene-molecule single-molecule junctions, where a specifically designed hexaphenyl aromatic chain molecule is covalently sandwiched between nanogapped graphene point contacts to create stable single-molecule junctions. Both theoretical and temperature-dependent experimental results consistently demonstrate that phenyl twisting in the aromatic chain molecule produces different microstates with different degrees of conjugation, thus leading to stochastic switching between high- and low-conductance states. These investigations offer new molecular design insights into building functional single-molecule electrical devices.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA