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1.
Cell Transplant ; 31: 9636897221107636, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35758252

RESUMEN

As a typical neuropeptide richly distributed in central and peripheral nervous systems, α-calcitonin-gene-related peptide (αCGRP) has recently been found to play a crucial role in bone development and metabolism, but the mechanisms involved are not fully uncovered. Here, this study aimed to investigate the effects and underlying molecular mechanisms of αCGRP in regulating the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Using microarray technology, gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) analyses revealed that osteogenic properties of BMSCs were facilitated and mitogen-activated protein kinase (MAPK) signaling pathway was upregulated by αCGRP in this process. Through western blot assay, we proved that αCGRP led to an increased phosphorylation level of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and p38 MAPK signaling cascades in a time-dependent manner. And αCGRP could promote differentiative capacity of BMSCs, showing upregulated mRNA and protein expression level of alkaline phosphatase (Alp), collagen type 1 (Col-1), osteopontin (Opn), and runt-related transcription factor 2 (Runx2), as well as increased ALP activity and calcified nodules. The addition of ERK1/2 or p38 MAPK inhibitor-U0126 or SB203580, resulted in an impaired osteogenic differentiation of BMSCs. Besides, inactivation of this signal transduction had negative impacts on proliferative activity and apoptotic process of αCGRP-mediated BMSCs. Our findings demonstrated that MAPK signaling pathway, at least in part, was responsible for the enhanced BMSCs' osteogenesis induced by αCGRP, which might offer us promising strategies for bone-related disorders.


Asunto(s)
Células Madre Mesenquimatosas , Osteogénesis , Fosfatasa Alcalina/metabolismo , Células de la Médula Ósea , Péptido Relacionado con Gen de Calcitonina/metabolismo , Diferenciación Celular , Células Cultivadas , Sistema de Señalización de MAP Quinasas , Transducción de Señal , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
2.
Nat Commun ; 13(1): 1410, 2022 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-35301285

RESUMEN

As conventional silicon-based transistors are fast approaching the physical limit, it is essential to seek alternative candidates, which should be compatible with or even replace microelectronics in the future. Here, we report a robust solid-state single-molecule field-effect transistor architecture using graphene source/drain electrodes and a metal back-gate electrode. The transistor is constructed by a single dinuclear ruthenium-diarylethene (Ru-DAE) complex, acting as the conducting channel, connecting covalently with nanogapped graphene electrodes, providing field-effect behaviors with a maximum on/off ratio exceeding three orders of magnitude. Use of ultrathin high-k metal oxides as the dielectric layers is key in successfully achieving such a high performance. Additionally, Ru-DAE preserves its intrinsic photoisomerisation property, which enables a reversible photoswitching function. Both experimental and theoretical results demonstrate these distinct dual-gated behaviors consistently at the single-molecule level, which helps to develop the different technology for creation of practical ultraminiaturised functional electrical circuits beyond Moore's law.

3.
Science ; 375(6579): 430-433, 2022 01 28.
Artículo en Inglés | MEDLINE | ID: mdl-35084955

RESUMEN

In thermodynamic equilibrium, current in metallic systems is carried by electronic states near the Fermi energy, whereas the filled bands underneath contribute little to conduction. Here, we describe a very different regime in which carrier distribution in graphene and its superlattices is shifted so far from equilibrium that the filled bands start playing an essential role, leading to a critical-current behavior. The criticalities develop upon the velocity of electron flow reaching the Fermi velocity. Key signatures of the out-of-equilibrium state are current-voltage characteristics that resemble those of superconductors, sharp peaks in differential resistance, sign reversal of the Hall effect, and a marked anomaly caused by the Schwinger-like production of hot electron-hole plasma. The observed behavior is expected to be common to all graphene-based superlattices.

4.
Sci Adv ; 8(12): eabm3541, 2022 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-35319984

RESUMEN

Single-molecule junctions (SMJs) offer a novel strategy for miniaturization of electronic devices. In this work, we realize a graphene-porphyrin-graphene SMJ driven by electric field and proton transfer in two configurations. In the transistor configuration with ionic liquid gating, an unprecedented field-effect performance is achieved with a maximum on/off ratio of ~4800 and a gate efficiency as high as ~179 mV/decade in consistence with the theoretical prediction. In the other configuration, controllable proton transfer, tautomerization switching, is directly observed with bias dependence. Room temperature proton transfer leads to a two-state conductance switching, and more precise tautomerization is detected, showing a four-state conductance switching at high bias voltages and low temperatures. Such an SMJ in two configurations provides new insights into not only building multifunctional molecular nanocircuits toward real applications but also deciphering the intrinsic properties of matters at the molecular scale.

5.
J Am Chem Soc ; 143(49): 20811-20817, 2021 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-34846141

RESUMEN

The aim of molecular electronics is to miniaturize active electronic devices and ultimately construct single-molecule nanocircuits using molecules with diverse structures featuring various functions, which is extremely challenging. Here, we realize a gate-controlled rectifying function (the on/off ratio reaches ∼60) and a high-performance field effect (maximum on/off ratio >100) simultaneously in an initially symmetric single-molecule photoswitch comprising a dinuclear ruthenium-diarylethene (Ru-DAE) complex sandwiched covalently between graphene electrodes. Both experimental and theoretical results consistently demonstrate that the initially degenerated frontier molecular orbitals localized at each Ru fragment in the open-ring Ru-DAE molecule can be tuned separately and shift asymmetrically under gate electric fields. This symmetric orbital shifting (AOS) lifts the degeneracy and breaks the molecular symmetry, which is not only essential to achieve a diode-like behavior with tunable rectification ratio and controlled polarity, but also enhances the field-effect on/off ratio at the rectification direction. In addition, this gate-controlled symmetry-breaking effect can be switched on/off by isomerizing the DAE unit between its open-ring and closed-ring forms with light stimulus. This new scheme offers a general and efficient strategy to build high-performance multifunctional molecular nanocircuits.

6.
Nano Lett ; 21(15): 6678-6683, 2021 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-34296602

RESUMEN

We describe how the out-of-plane dielectric polarizability of monolayer graphene influences the electrostatics of bilayer graphene-both Bernal (BLG) and twisted (tBLG). We compare the polarizability value computed using density functional theory with the output from previously published experimental data on the electrostatically controlled interlayer asymmetry potential in BLG and data on the on-layer density distribution in tBLG. We show that monolayers in tBLG are described well by polarizability αexp = 10.8 Å3 and effective out-of-plane dielectric susceptibility ϵz = 2.5, including their on-layer electron density distribution at zero magnetic field and the interlayer Landau level pinning at quantizing magnetic fields.

7.
J Colloid Interface Sci ; 601: 793-802, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34102407

RESUMEN

Multi-dimensional metal oxides have become a promising alternative electrode material for supercapacitors due to their inherent large surface area. Herein, P-doped NiCo2O4/NiMoO4 multi-dimensional nanostructures are synthesized on carbon clothes (CC) with a continuous multistep strategy. Especially, P has the best synergistic effect with transition metals, such as optimal deprotonation energy and OH- adsorption energy, which can further enhance electrochemical reaction activity. For the above reasons, the P-NiCo2O4/NiMoO4@CC electrode exhibits an ultra-high specific capacitance of 2334.0 F g-1 at 1 A g-1. After 1500 cycles at a current density of 10 A g-1, its specific capacity still maintains 93.7%. Besides, a P-NiCo2O4/NiMoO4@CC//activated carbon device (hybrid supercapacitor or device) was also prepared with a maximum energy density of 45.1 Wh kg-1 at a power density of 800 W kg-1. In particular, the capacity retention rate is still 89.97% after 8000 cycles due to its excellent structural stability. Our work demonstrates the vast potential of multi-dimensional metal oxides in energy storage.

8.
J Colloid Interface Sci ; 599: 158-167, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33933790

RESUMEN

Research on environmentally friendly energy storage devices is an important strategy to solve the energy crisis and environmental pollution. Herein, a novel self-supporting electrode based on multi-dimensional Co3O4/NiCo2O4 hierarchical flakes coating on graphene/carbon sphere (rGO/CS) conductive substrate is reasonably designed. Firstly, a simple hydrothermal method is used to synthesize NiCo2O4 with both flake and nanoneedle morphology on the rGO/CS substrate. Subsequently, Co3O4/NiCo2O4@rGO/CS is obtained by in-situ growth of metal organic frameworks polyhedrons on the surface of NiCo2O4 flakes followed by calcination. In the unique structure, benefitting from the synergy between the substrate and multi-element transition metal oxides, the integrated film shows good conductivity, high specific surface area and abundant active sites. Thus, the binder-free electrode exhibits an ultra-high specific capacitance of 3876.6 F g-1 (538.4 mA h g-1) at 1 A g-1. A hybrid supercapacitor is assembled with activated carbon as the negative electrode and Co3O4/NiCo2O4@rGO/CS as the positive electrode, the device shows a highest energy density of 56.5 Wh kg-1 at a power density of 800 W kg-1. After 6000 charge-discharge cycles, 92.5% of the initial capacitance can be still maintained, indicating its good application prospects in energy storage materials.

9.
Angew Chem Int Ed Engl ; 60(22): 12274-12278, 2021 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-33650169

RESUMEN

Charge transport in a single-molecule junction is extraordinarily sensitive to both the internal electronic structure of a molecule and its microscopic environment. Two distinct conductance states of a prototype terphenyl molecule are observed, which correspond to the bistability of outer phenyl rings at each end. An azobenzene unit is intentionally introduced through atomically precise side-functionalization at the central ring of the terphenyl, which is reversibly isomerized between trans and cis forms by either electric or optical stimuli. Both experiment and theory demonstrate that the azobenzene side-group delicately modulates charge transport in the backbone via a single-molecule stereoelectronic effect. We reveal that the dihedral angle between the central and outer phenyl ring, as well as the corresponding rotation barrier, is subtly controlled by isomerization, while the behaviors of the phenyl ring away from the azobenzene are hardly affected. This tunability offers a new route to precisely engineer multiconfigurational single-molecule memories, switches, and sensors.

10.
Acta Pharmacol Sin ; 42(8): 1347-1353, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33116249

RESUMEN

To discover effective drugs for COVID-19 treatment amongst already clinically approved drugs, we developed a high throughput screening assay for SARS-CoV-2 virus entry inhibitors using SARS2-S pseudotyped virus. An approved drug library of 1800 small molecular drugs was screened for SARS2 entry inhibitors and 15 active drugs were identified as specific SARS2-S pseudovirus entry inhibitors. Antiviral tests using native SARS-CoV-2 virus in Vero E6 cells confirmed that 7 of these drugs (clemastine, amiodarone, trimeprazine, bosutinib, toremifene, flupenthixol, and azelastine) significantly inhibited SARS2 replication, reducing supernatant viral RNA load with a promising level of activity. Three of the drugs were classified as histamine receptor antagonists with clemastine showing the strongest anti-SARS2 activity (EC50 = 0.95 ± 0.83 µM). Our work suggests that these 7 drugs could enter into further in vivo studies and clinical investigations for COVID-19 treatment.


Asunto(s)
Antivirales/uso terapéutico , COVID-19/tratamiento farmacológico , Reposicionamiento de Medicamentos , SARS-CoV-2/efectos de los fármacos , Internalización del Virus/efectos de los fármacos , Línea Celular , Aprobación de Drogas , Ensayos Analíticos de Alto Rendimiento , Humanos , Pruebas de Sensibilidad Microbiana , SARS-CoV-2/fisiología , Glicoproteína de la Espiga del Coronavirus/efectos de los fármacos
11.
J Colloid Interface Sci ; 583: 288-298, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-33007585

RESUMEN

With the increasing demand for miniaturization and portable energy storage system, it is an urgent necessary that developing high volumetric energy density supercapacitors with small volumes. Herein, an integrated self-supporting CoZnNiS@CNTs/rGO composite film electrode with the thickness of about 6 µm was designed. In the unique structure, porous CNTs/rGO film is served as conductive substrate to support the CoZn-MOFs derived vertically oriented two-dimensional CoZnNiS nanoarrays. The self-supporting film endows the electrode a high volumetric mass density of 1.28 g cm-3 and superior electron-ion transport channel, which displays a maximum specific capacitance of 1349.2 F g-1 as well as high volumetric capacity of 1727.0 F cm-3 at 1 A g-1. Besides, a porous film of pure carbon materials (carbon spheres integrated graphene) was designed and used as the negative electrode in supercapacitor. When assembled a hybrid supercapacitor based on the above two self-supporting electrodes, the device delivers up an ultra-high volumetric/gravimetric energy density of 65.2 W h L-1 (60.4 W h kg-1) at a power density of 1308 W L-1 (1200 W kg-1). Moreover, the asymmetric supercapacitor also displays an ultra-long lifetime with 90.6% retention after 10,000 cycles. These outstanding performances make the CoZnNiS@CNTs/rGO electrode could be a promising candidate for next-generation high volumetric/gravimetric energy density supercapacitors, especially in the limited space.

12.
Zhongguo Zhong Yao Za Zhi ; 45(18): 4416-4422, 2020 Sep.
Artículo en Chino | MEDLINE | ID: mdl-33164371

RESUMEN

Twenty-six batches of Gardeniae Fructus from different producing area were collected for the development of the fingerprint, and the main components of Gardeniae Fructus were identified by liquid chromatography-mass spectrometry. The producing areas of Gardeniae Fructus were distinguished by chemical pattern recognition technology, and the index components of Gardeniae Fructus were quantitated. An UPLC wavelength switching method was adopted, and the separation was carried out on a Waters Acquity UPLC HASS C_(18)(2.1 mm×100 mm, 1.7 µm) column using the mobile phase of acetonitrile-0.5% formic acid water for gradient elution. Principal component analysis(PCA) and orthogonal partial least square discriminant analysis(OPLS-DA) were used for the data ana-lysis. The results showed that the similarity of 26 batches of Gardeniae Fructus was more than 0.89, and ten common peaks were defined. Sixteen compounds including monoterpenes, iridoids and diterpenoids were identified by reference identification, literature comparison and high-resolution mass spectrometry data analysis. The distinguishment of origin of Gardeniae Fructus was realized by PCA and OPLS-DA analysis, and two quality differential markers were screened as geniposide and crocin Ⅰ. The contents of crocin Ⅰ, crocin Ⅱ and geniposide in Gardeniae Fructus from different places were different. These results will provide reference for the geographical origin traceability of Gardeniae Fructus.


Asunto(s)
Medicamentos Herbarios Chinos , Gardenia , Cromatografía Líquida de Alta Presión , Frutas , Control de Calidad
13.
Nat Commun ; 11(1): 5756, 2020 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-33188210

RESUMEN

In quantizing magnetic fields, graphene superlattices exhibit a complex fractal spectrum often referred to as the Hofstadter butterfly. It can be viewed as a collection of Landau levels that arise from quantization of Brown-Zak minibands recurring at rational (p/q) fractions of the magnetic flux quantum per superlattice unit cell. Here we show that, in graphene-on-boron-nitride superlattices, Brown-Zak fermions can exhibit mobilities above 106 cm2 V-1 s-1 and the mean free path exceeding several micrometers. The exceptional quality of our devices allows us to show that Brown-Zak minibands are 4q times degenerate and all the degeneracies (spin, valley and mini-valley) can be lifted by exchange interactions below 1 K. We also found negative bend resistance at 1/q fractions for electrical probes placed as far as several micrometers apart. The latter observation highlights the fact that Brown-Zak fermions are Bloch quasiparticles propagating in high fields along straight trajectories, just like electrons in zero field.

14.
Chin J Nat Med ; 18(9): 666-676, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32928510

RESUMEN

This study engineered ß-carotene ketolase CrtW and ß-carotene hydroxylase CrtZ to improve biosynthesis of astaxanthin in Escherichia coli. Firstly, crtW was randomly mutated to increase CrtW activities on conversion from ß-carotene to astaxanthin. A crtW* mutant with A6T, T105A and L239M mutations has improved 5.35-fold astaxanthin production compared with the wild-type control. Secondly, the expression levels of crtW* and crtZ on chromosomal were balanced by simultaneous modulation RBS regions of their genes using RBS library. The strain RBS54 selected from RBS library, directed the pathway exclusively towards the desired product astaxanthin as predominant carotenoid (99%). Lastly, the number of chromosomal copies of the balanced crtW-crtZ cassette from RBS54 was increased using a Cre-loxP based technique, and a strain with 30 copies of the crtW*-crtZ cassette was selected. This final strain DL-A008 had a 9.8-fold increase of astaxanthin production compared with the wild-type control. Fed-batch fermentation showed that DL-A008 produced astaxanthin as predominant carotenoid (99%) with a specific titer of 0.88 g·L-1 without addition of inducer. In conclusion, through constructing crtW mutation, balancing the expression levels between crtW* and crtZ, and increasing the copy number of the balanced crtW*-crtZ cassette, the activities of ß-carotene ketolase and ß-carotene hydroxylase were improved for conversion of ß-carotene to astaxanthin with higher efficiency. The series of conventional and novel metabolic engineering strategies were designed and applied to construct the astaxanthin hetero-producer strain of E. coli, possibly offering a general approach for the construction of stable hetero-producer strains for other natural products.


Asunto(s)
Escherichia coli/metabolismo , Ingeniería Metabólica/métodos , Oxigenasas de Función Mixta/genética , Oxigenasas/genética , Vías Biosintéticas , Carotenoides/química , Carotenoides/metabolismo , Oxigenasas de Función Mixta/química , Oxigenasas/química , Xantófilas/química , Xantófilas/metabolismo
15.
Redox Biol ; 36: 101672, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32828017

RESUMEN

Oxidative stress is an important pathogenic manifestation of Alzheimer's disease (AD) that contributes to synaptic dysfunction, which precedes Aß accumulation and neurofibrillary tangle formation. However, the molecular machineries that govern the decline of antioxidative defence in AD remains to be elucidated, and effective candidate for AD treatment is limited. Here, we showed that the decreases in the inhibitor of apoptosis-stimulating protein of p53 (iASPP) was associated with the vulnerability to oxidative stress in the amyloid precursor protein (APP)/presenilin 1 (PS1) mouse brain. Treatment with an antioxidant, syringin, could ameliorate AD-related pathologic and behavioural impairments. Interestingly, syringin treatment resulted in an upregulation of iASPP and the increase in the interaction of iASPP with Kelchlike ECH-associating protein 1 (Keap1). Syringin reduced neuronal apoptosis independently of p53. We confirmed that syringin-induced enhancement of antioxidant defenses involved the stabilization of Nrf2 in overexpressing human Swedish mutant APP (APPswe) cells in vitro. Syringin-mediated Nrf2 nuclear translocation facilitated the activation of the Nrf2 downstream genes via iASPP/Nrf2 axis. Our results demonstrate that syringin-mediated increases of iASPP-Keap1 interaction restore cellular redox balance. Further study on the syringin-iASPP interactions may help in understanding the regulatory mechanism and designing novel potent modulators for AD treatment.


Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/genética , Péptidos beta-Amiloides/metabolismo , Animales , Apoptosis , Disfunción Cognitiva/tratamiento farmacológico , Glucósidos , Proteína 1 Asociada A ECH Tipo Kelch/genética , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Ratones , Ratones Transgénicos , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Plasticidad Neuronal , Estrés Oxidativo , Fenilpropionatos , Proteína p53 Supresora de Tumor
16.
Acta Pharmacol Sin ; 41(9): 1133-1140, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32555446

RESUMEN

Since the outbreak of novel coronavirus pneumonia (COVID-19) in December 2019, more than 2,500,000 people worldwide have been diagnosed with SARS-CoV-2 as of April 22. In response to this epidemic, China has issued seven trial versions of diagnosis and treatment protocol for COVID-19. According to the information that we have collected so far, this article provides an overview of potential therapeutic drugs and compounds with much attention, including favipiravir and hydroxychloroquine, as well as traditional Chinese medicine, which have been reported with good clinical treatment effects. Moreover, with further understanding of SARS-CoV-2 virus, new drugs targeting specific SARS-CoV-2 viral components arise and investigations on these novel anti-SARS-CoV-2 agents are also reviewed.


Asunto(s)
Antivirales/farmacología , Betacoronavirus/efectos de los fármacos , Infecciones por Coronavirus , Medicina Tradicional China/métodos , Pandemias , Neumonía Viral , Betacoronavirus/fisiología , COVID-19 , Protocolos Clínicos , Infecciones por Coronavirus/tratamiento farmacológico , Infecciones por Coronavirus/fisiopatología , Humanos , Neumonía Viral/tratamiento farmacológico , Neumonía Viral/etiología , Neumonía Viral/fisiopatología , SARS-CoV-2
17.
Br J Ophthalmol ; 104(6): 748-751, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32265202

RESUMEN

PURPOSE: To report the ocular characteristics and the presence of viral RNA of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in conjunctival swab specimens in a patient with confirmed 2019 novel coronavirus disease (COVID-19). PARTICIPANT AND METHODS: A 30-year-old man with confirmed COVID-19 and bilateral acute conjunctivitis which occurred 13 days after illness onset. Based on detailed ophthalmic examination, reverse transcription PCR (RT-PCR) was performed to detect SARS-CoV-2 virus in conjunctival swabs. The ocular characteristics, presence of viral RNA and viral dynamics of SARS-CoV-2 in the conjunctival specimens were evaluated. RESULTS: Slit lamp examination showed bilateral acute follicular conjunctivitis. RT-PCR assay demonstrated the presence of viral RNA in conjunctival specimen 13 days after onset (cycle threshold value: 31). The conjunctival swab specimens remained positive for SARS-CoV-2 on 14 and 17 days after onset. On day 19, RT-PCR result was negative for SARS-CoV-2. CONCLUSION: SARS-CoV-2 is capable of causing ocular complications such as viral conjunctivitis in the middle phase of illness. Precautionary measures are recommended when examining infected patients throughout the clinical course of the infection. However, conjunctival sampling might not be useful for early diagnosis because the virus may not appear initially in the conjunctiva.


Asunto(s)
Antivirales/uso terapéutico , Betacoronavirus/patogenicidad , Conjuntivitis Viral/diagnóstico , Infecciones por Coronavirus/fisiopatología , Soluciones Oftálmicas/uso terapéutico , Neumonía Viral/fisiopatología , ARN Viral/análisis , Ribavirina/uso terapéutico , Adulto , COVID-19 , Conjuntivitis Viral/tratamiento farmacológico , Infecciones por Coronavirus/complicaciones , Infecciones por Coronavirus/virología , Humanos , Masculino , Cavidad Nasal/virología , Pandemias , Faringe/virología , Neumonía Viral/complicaciones , Neumonía Viral/virología , SARS-CoV-2 , Resultado del Tratamiento
18.
Int J Infect Dis ; 93: 224-230, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32045697

RESUMEN

OBJECTIVES: Bordetella pertussis is a highly contagious respiratory agent and is the causative pathogen of pertussis, which primarily affects children. Current diagnostic techniques for this pathogen have a variety of limitations including a long culture time, low bacterial load, and lack of specificity. METHODS: This article reports the development of a one-tube nested quantitative real-time PCR assay using the locked nucleic acid (LNA) technique (LNA-OTN-q-PCR), targeting the BP485 gene and using a simple inexpensive extraction method. A total of 130 clinical samples from patients with clinically suspected pertussis, collected from the Children's Hospital of Hebei, China, were tested by LNA-OTN-q-PCR assay. RT-PCR and two-step semi-nested PCR assays were performed in parallel for comparison. RESULTS: Only strains of B. pertussis were identified as positive, whereas all of the remaining strains were appropriately identified as negative by the LNA-OTN-q-PCR assay. A single copy per reaction can be detected by the LNA-OTN-q-PCR assay. Additionally, the sensitivity of this method was 100 times that of the RT-PCR assay (100 copies per reaction). Sixty-three of the 130 clinical samples were detected positive by LNA-OTN-q-PCR assay; in contrast, RT-PCR was able to detect only 41 positive samples. Following this, all 63 samples were positively identified by two-step semi-nested PCR. Compared with the two-step semi-nested PCR assay, both the specificity and sensitivity of the LNA-OTN-q-PCR assay using purified DNA and crude extract were 100%. CONCLUSIONS: This assay was able to detect B. pertussis infection with high sensitivity and specificity. This test shows great potential as a promising technique to detect B. pertussis in both clinical laboratories and public health settings.


Asunto(s)
Bordetella pertussis/aislamiento & purificación , Oligonucleótidos , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Tos Ferina/diagnóstico , Bordetella pertussis/genética , Niño , China , ADN Bacteriano , Femenino , Humanos , Masculino , Sensibilidad y Especificidad , Tos Ferina/microbiología
19.
Hortic Res ; 6: 100, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31666961

RESUMEN

Heat stress is a serious and widespread threat to the quality and yield of many crop species, including grape (Vitis vinifera L.), which is cultivated worldwide. Here, we conducted phosphoproteomic and acetylproteomic analyses of leaves of grape plants cultivated under four distinct temperature regimes. The phosphorylation or acetylation of a total of 1011 phosphoproteins with 1828 phosphosites and 96 acetyl proteins with 148 acetyl sites changed when plants were grown at 35 °C, 40 °C, and 45 °C in comparison with the proteome profiles of plants grown at 25 °C. The greatest number of changes was observed at the relatively high temperatures. Functional classification and enrichment analysis indicated that phosphorylation, rather than acetylation, of serine/arginine-rich splicing factors was involved in the response to high temperatures. This finding is congruent with previous observations by which alternative splicing events occurred more frequently in grapevine under high temperature. Changes in acetylation patterns were more common than changes in phosphorylation patterns in photosynthesis-related proteins at high temperatures, while heat-shock proteins were associated more with modifications involving phosphorylation than with those involving acetylation. Nineteen proteins were identified with changes associated with both phosphorylation and acetylation, which is consistent with crosstalk between these posttranslational modification types.

20.
Int J Infect Dis ; 86: 108-113, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31288091

RESUMEN

OBJECTIVES: Pertussis is a highly transmissible acute respiratory infection caused by the bacterial pathogen Bordetella pertussis. The purpose of this study was to develop a rapid, simple and sensitive diagnostic test for detecting this pathogen. METHODS: Here we present a recombinase aided amplification (RAA) assay incorporating competitive internal amplification control (IAC) to detect Bordetella pertussis using the DNA obtained by boiling. This assay was performed in a single closed tube at 39°C within 30min. A total of 115 clinical samples suspected of pertussis were collected and tested by the internally controlled RAA assay using both extracted DNA with the commercial kit and the DNA obtained by boiling. For comparison, the real-time PCR (RT-PCR) was also performed with DNA extraction in parallel. RESULTS: The sensitivity of the internally controlled RAA assay was 101 copies or 10CFU/ml per reaction in detecting plasmid DNA or B. pertussis strain. The optimum concentration of the IAC plasmid was determined to be 100 copies, and the introduction of IAC effectively reduced the occurrence of false negatives. Compared to the RT-PCR, RAA results with DNA extraction obtained 100% sensitivity and specificity, and the RAA results with heat-treated DNA showed 85.96% sensitivity and 100% specificity. CONCLUSION: With the advantages of 45min turn-around time and simple steps of DNA purification, this assay could become a useful diagnostic tool for Bordetella pertussis detection and is potentially suitable for point-of-care identification to guide prompt clinical treatment.


Asunto(s)
Bordetella pertussis/aislamiento & purificación , Técnicas de Amplificación de Ácido Nucleico/métodos , Recombinasas , Tos Ferina/diagnóstico , Bordetella pertussis/genética , Niño , Preescolar , ADN Bacteriano/aislamiento & purificación , Femenino , Calor , Humanos , Lactante , Masculino , Técnicas de Amplificación de Ácido Nucleico/normas , Reacción en Cadena en Tiempo Real de la Polimerasa , Estándares de Referencia , Sensibilidad y Especificidad
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