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1.
Angew Chem Int Ed Engl ; 63(19): e202316717, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38477147

RESUMEN

The electrolytes for lithium metal batteries (LMBs) are plagued by a low Li+ transference number (T+) of conventional lithium salts and inability to form a stable solid electrolyte interphase (SEI). Here, we synthesized a self-folded lithium salt, lithium 2-[2-(2-methoxy ethoxy)ethoxy]ethanesulfonyl(trifluoromethanesulfonyl) imide (LiETFSI), and comparatively studied with its structure analogue, lithium 1,1,1-trifluoro-N-[2-[2-(2-methoxyethoxy)ethoxy)]ethyl]methanesulfonamide (LiFEA). The special anion chemistry imparts the following new characteristics: i) In both LiFEA and LiETFSI, the ethylene oxide moiety efficiently captures Li+, resulting in a self-folded structure and high T+ around 0.8. ii) For LiFEA, a Li-N bond (2.069 Å) is revealed by single crystal X-ray diffraction, indicating that the FEA anion possesses a high donor number (DN) and thus an intensive interphase "self-cleaning" function for an ultra-thin and compact SEI. iii) Starting from LiFEA, an electron-withdrawing sulfone group is introduced near the N atom. The distance of Li-N is tuned from 2.069 Šin LiFEA to 4.367 Šin LiETFSI. This alteration enhances ionic separation, achieves a more balanced DN, and tunes the self-cleaning intensity for a reinforced SEI. Consequently, the fast charging/discharging capability of LMBs is progressively improved. This rationally tuned anion chemistry reshapes the interactions among Li+, anions, and solvents, presenting new prospects for advanced LMBs.

2.
Emerg Infect Dis ; 29(2): 371-380, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36692451

RESUMEN

The Omicron variant of SARS-CoV-2 has become dominant in most countries and has raised significant global health concerns. As a global commerce center, New York, New York, USA, constantly faces the risk for multiple variant introductions of SARS-CoV-2. To elucidate the introduction and transmission of the Omicron variant in the city of New York, we created a comprehensive genomic and epidemiologic analysis of 392 Omicron virus specimens collected during November 25-December 11, 2021. We found evidence of 4 independent introductions of Omicron subclades, including the Omicron subclade BA.1.1 with defining substitution of R346K in the spike protein. The continuous genetic divergence within each Omicron subclade revealed their local community transmission and co-circulation in New York, including both household and workplace transmissions supported by epidemiologic evidence. Our study highlights the urgent need for enhanced genomic surveillance and effective response planning for better prevention and management of emerging SARS-CoV-2 variants.


Asunto(s)
COVID-19 , Humanos , New York/epidemiología , COVID-19/epidemiología , SARS-CoV-2/genética , Comercio
3.
Brief Bioinform ; 22(2): 1267-1278, 2021 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-33126244

RESUMEN

Accessory proteins play important roles in the interaction between coronaviruses and their hosts. Accordingly, a comprehensive study of the compositional diversity and evolutionary patterns of accessory proteins is critical to understanding the host adaptation and epidemic variation of coronaviruses. Here, we developed a standardized genome annotation tool for coronavirus (CoroAnnoter) by combining open reading frame prediction, transcription regulatory sequence recognition and homologous alignment. Using CoroAnnoter, we annotated 39 representative coronavirus strains to form a compositional profile for all of the accessary proteins. Large variations were observed in the number of accessory proteins of 1-10 for different coronaviruses, with SARS-CoV-2 and SARS-CoV having the most (9 and 10, respectively). The variation between SARS-CoV and SARS-CoV-2 accessory proteins could be traced back to related coronaviruses in other hosts. The genomic distribution of accessory proteins had significant intra-genus conservation and inter-genus diversity and could be grouped into 1, 4, 2 and 1 types for alpha-, beta-, gamma-, and delta-coronaviruses, respectively. Evolutionary analysis suggested that accessory proteins are more conservative locating before the N-terminal of proteins E and M (E-M), while they are more diverse after these proteins. Furthermore, comparison of virus-host interaction networks of SARS-CoV-2 and SARS-CoV accessory proteins showed that they share multiple antiviral signaling pathways, those involved in the apoptotic process, viral life cycle and response to oxidative stress. In summary, our study provides a tool for coronavirus genome annotation and builds a comprehensive profile for coronavirus accessory proteins covering their composition, classification, evolutionary pattern and host interaction.


Asunto(s)
Evolución Biológica , COVID-19/virología , SARS-CoV-2/metabolismo , Proteínas Virales/genética , Proteínas Virales/metabolismo , Genes Virales , Humanos , Anotación de Secuencia Molecular , Sistemas de Lectura Abierta , Mapas de Interacción de Proteínas , SARS-CoV-2/genética
4.
J Med Virol ; 95(1): e28411, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36524893

RESUMEN

A series of nonpharmaceutical interventions (NPIs) was launched in Beijing, China, on January 24, 2020, to control coronavirus disease 2019. To reveal the roles of NPIs on the respiratory syncytial virus (RSV), respiratory specimens collected from children with acute respiratory tract infection between July 2017 and Dec 2021 in Beijing were screened by capillary electrophoresis-based multiplex PCR (CEMP) assay. Specimens positive for RSV were subjected to a polymerase chain reaction (PCR) and genotyped by G gene sequencing and phylogenetic analysis using iqtree v1.6.12. The parallel and fixed (paraFix) mutations were analyzed with the R package sitePath. Clinical data were compared using SPSS 22.0 software. Before NPIs launched, each RSV endemic season started from October/November to February/March of the next year in Beijing. After that, the RSV positive rate abruptly dropped from 31.93% in January to 4.39% in February 2020; then, a dormant state with RSV positive rates ≤1% from March to September, a nearly dormant state in October (2.85%) and November (2.98%) and a delayed endemic season in 2020, and abnormal RSV positive rates remaining at approximately 10% in summer until September 2021 were detected. Finally, an endemic RSV season returned in October 2021. There was a game between Subtypes A and B, and RSV-A replaced RSV-B in July 2021 to become the dominant subtype. Six RSV-A and eight RSV-B paraFix mutations were identified on G. The percentage of severe pneumonia patients decreased to 40.51% after NPIs launched. NPIs launched in Beijing seriously interfered with the endemic season of RSV.


Asunto(s)
COVID-19 , Infecciones por Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Infecciones del Sistema Respiratorio , Niño , Humanos , Lactante , Infecciones por Virus Sincitial Respiratorio/epidemiología , Infecciones por Virus Sincitial Respiratorio/prevención & control , Beijing/epidemiología , Filogenia , COVID-19/epidemiología , COVID-19/prevención & control , Virus Sincitial Respiratorio Humano/genética , Reacción en Cadena de la Polimerasa Multiplex
5.
J Med Virol ; 95(1): e28290, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36367083

RESUMEN

The geographic range of Zika virus (ZIKV) has expanded from Asia to the Americas, leading to the 2015-2016 pandemic with enhanced neurovirulence. At present, ZIKV is continuously circulating in many Southeast Asian countries. Unfortunately, the persistent evolution of ZIKV in Southeast Asia and its influence on the biological characteristics of the virus remain incompletely understood. In this study, the in vitro and in vivo properties of a new ZIKV isolate obtained from Cambodia in 2019 (CAM/2019) were characterized and compared with those of the Cambodian strain (CAM/2010). Compared with CAM/2010, the CAM/2019 virus showed similar plaque morphology and growth curves in cell cultures and induced comparable viremia and organ viral loads profiles in both BALB/c and A129 (IFNAR1-/- ) mice upon intraperitoneal (i.p.) inoculation. Remarkably, the CAM/2019 virus exhibited enhanced neurovirulence in neonatal mice compared with CAM/2010, with a 74-fold reduction in the 50% lethal dose (LD50 ). Consistently, CAM/2019 produced higher viral loads in the brains of BALB/c neonatal mice than CAM/2010 did. Sequence alignment showed that the CAM/2019 virus has acquired 12 amino acid substitutions, several of which were found to be associated with neurovirulence. In particular, the CAM/2019 virus shared an A1204T substitution in NS2A with the Thai isolate SI-BKK02 that was isolated from a microcephaly case. Taken together, our results indicate that a ZIKV strain isolated with specific mutations has emerged in Cambodia, highlighting the need for extensive molecular and disease surveillance in Cambodia and other Asian countries.


Asunto(s)
Infección por el Virus Zika , Virus Zika , Animales , Ratones , Filogenia , Infección por el Virus Zika/epidemiología , Cambodia/epidemiología , Asia/epidemiología
6.
J Med Virol ; 95(12): e29278, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-38088537

RESUMEN

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants continue to emerge and cocirculate in humans and wild animals. The factors driving the emergence and replacement of novel variants and recombinants remain incompletely understood. Herein, we comprehensively characterized the competitive fitness of SARS-CoV-2 wild type (WT) and three variants of concern (VOCs), Alpha, Beta and Delta, by coinfection and serial passaging assays in different susceptible cells. Deep sequencing analyses revealed cell-specific competitive fitness: the Beta variant showed enhanced replication fitness during serial passage in Caco-2 cells, whereas the WT and Alpha variant showed elevated fitness in Vero E6 cells. Interestingly, a high level of neutralizing antibody sped up competition and completely reshaped the fitness advantages of different variants. More importantly, single clone purification identified a significant proportion of homologous recombinants that emerged during the passage history, and immune pressure reduced the frequency of recombination. Interestingly, a recombination hot region located between nucleotide sites 22,995 and 28,866 of the viral genomes could be identified in most of the detected recombinants. Our study not only profiled the variable competitive fitness of SARS-CoV-2 under different conditions, but also provided direct experimental evidence of homologous recombination between SARS-CoV-2 viruses, as well as a model for investigating SARS-CoV-2 recombination.


Asunto(s)
COVID-19 , SARS-CoV-2 , Animales , Humanos , SARS-CoV-2/genética , Células CACO-2 , Recombinación Homóloga , Glicoproteína de la Espiga del Coronavirus
7.
Nano Lett ; 22(14): 5936-5943, 2022 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-35819353

RESUMEN

A fluorinated amide molecule with two functional segments, namely, an amide group with a high donor number to bind lithium ions and a fluorine chain to expel carbonate solvents and mediate the formation of LiF, was designed to regulate the interfacial chemistry. As expected, the additive preferably appears in the first solvation sheath of lithium ions and is electrochemically reduced on the anode, and thus an inorganic-rich solid electrolyte interphase is generated. The morphology of deposited lithium metal evolves from brittle dendrites into a granular shape. Consequently, the Li||LiFePO4 cell shows an excellent capacity retention of 92.7% at a high rate of 5 C after 800 cycles. Besides, the Li||LiNi0.8Co0.1Mn0.1O2 cell succeeds to maintain 98.1% of the initial capacity after 100 cycles at 1 C. Our designing of N,N-diethyl- 2,3,3,3-tetrafluoropropionamide (denoted as DETFP) highlights the importance of a "high donor number" and may shed light on the design principles of electrolytes for high performance batteries.

8.
Angew Chem Int Ed Engl ; 62(35): e202306948, 2023 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-37408357

RESUMEN

Improved durability, enhanced interfacial stability, and room temperature applicability are desirable properties for all-solid-state lithium metal batteries (ASSLMBs), yet these desired properties are rarely achieved simultaneously. Here, in this work, it is noticed that the huge resistance at Li metal/electrolyte interface dominantly impeded the normal cycling of ASSLMBs especially at around room temperature (<30 °C). Accordingly, a supramolecular polymer ion conductor (SPC) with "weak solvation" of Li+ was prepared. Benefiting from the halogen-bonding interaction between the electron-deficient iodine atom (on 1,4-diiodotetrafluorobenzene) and electron-rich oxygen atoms (on ethylene oxide), the O-Li+ coordination was significantly weakened. Therefore, the SPC achieves rapid Li+ transport with high Li+ transference number, and importantly, derives a unique Li2 O-rich SEI with low interfacial resistance on lithium metal surface, therefore enabling stable cycling of ASSLMBs even down to 10 °C. This work is a new exploration of halogen-bonding chemistry in solid polymer electrolyte and highlights the importance of "weak solvation" of Li+ in the solid-state electrolyte for room temperature ASSLMBs.

9.
BMC Bioinformatics ; 23(1): 504, 2022 Nov 24.
Artículo en Inglés | MEDLINE | ID: mdl-36434502

RESUMEN

BACKGROUND: Identifying polymorphism clades on phylogenetic trees could help detect punctual mutations that are associated with viral functions. With visualization tools coloring the tree, it is easy to visually find clades where most sequences have the same polymorphism state. However, with the fast accumulation of viral sequences, a computational tool to automate this process is urgently needed. RESULTS: Here, by implementing a branch-and-bound-like search method, we developed an R package named sitePath to identify polymorphism clades automatically. Based on the identified polymorphism clades, fixed and parallel mutations could be inferred. Furthermore, sitePath also integrated visualization tools to generate figures of the calculated results. In an example with the influenza A virus H3N2 dataset, the detected fixed mutations coincide with antigenic shift mutations. The highly specificity and sensitivity of sitePath in finding fixed mutations were achieved for a range of parameters and different phylogenetic tree inference software. CONCLUSIONS: The result suggests that sitePath can identify polymorphism clades per site. The clustering of sequences on a phylogenetic tree can be used to infer fixed and parallel mutations. High-quality figures of the calculated results could also be generated by sitePath.


Asunto(s)
Subtipo H3N2 del Virus de la Influenza A , Gripe Humana , Humanos , Filogenia , Subtipo H3N2 del Virus de la Influenza A/genética , Mutación , Programas Informáticos , Polimorfismo Genético
10.
J Med Virol ; 94(10): 4830-4838, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35705528

RESUMEN

Among numerous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concerns, Omicron is more infectious and immune-escaping, while Delta is more pathogenic. Here, we provide evidence for both intervariant and intravariant recombination of the rapidly evolving new SARS-CoV-2 genomes, including XD/XE/XF and BA.3, raising concerns of potential more infectious, immune-escaping, and disease-causing Omicron and Delta-Omicron variants.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Recombinación Genética , SARS-CoV-2/genética
11.
Mikrochim Acta ; 189(11): 420, 2022 10 17.
Artículo en Inglés | MEDLINE | ID: mdl-36251083

RESUMEN

An effective, selective, and multicolor colorimetric assay for Cu2+ detection based on the regulation of peroxidase-like nanozyme-mediated etching of gold nanorods (Au NRs) is proposed. Cu2+-creatinine complex is selected as the nanozyme that exhibits excellent peroxidase-like activity even in the case of low concentration of Cu2+, which can catalyze 3,3,5,5-tetramethylbenzidine (TMB) to produce oxidized TMB (TMB+) in the presence of hydrogen peroxide, and TMB+ is oxidized to generate TMB2+ after adding H+, and the TMB2+ can etch Au NRs. The determination of Cu2+ is achieved based on the blue shift of the longitudinal localized surface plasmon resonance peak of Au NRs. Under the optimal conditions, the developed colorimetric assay exhibits high sensitivity for the detection of Cu2+ (limit of detection is 0.034 µM) with a wide linear range of 0.05-4.0 µM (R2 = 0.987). The solution shows a rainbow-like color in response to the increase of Cu2+ concentration, which can realize the semi-quantitative detection of Cu2+ by naked eyes. In addition, the developed method exhibits excellent selectivity for Cu2+-detection. The established method was used for the determination of Cu2+ in lake water, soil, and normal human serum with satisfactory recovery of spiked samples.


Asunto(s)
Oro , Nanotubos , Humanos , Bencidinas , Colorimetría/métodos , Cobre , Creatinina , Peróxido de Hidrógeno , Peroxidasas , Suelo
12.
Int J Mol Sci ; 23(11)2022 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-35682933

RESUMEN

Being in the epicenter of the COVID-19 pandemic, our lab tested 193,054 specimens for SARS-CoV-2 RNA by diagnostic multiplex reverse transcription polymerase chain reaction (mRT-PCR) starting in March 2020, of which 17,196 specimens resulted positive. To investigate the dynamics of virus molecular evolution and epidemiology, whole genome amplification (WGA) and Next Generation Sequencing (NGS) were performed on 9516 isolates. 7586 isolates with a high quality were further analyzed for the mutation frequency and spectrum. Lastly, we evaluated the utility of the mRT-PCR detection pattern among 26 reinfected patients with repeat positive testing three months after testing negative from the initial infection. Our results show a continuation of the genetic divergence in viral genomes. Furthermore, our results indicate that independent mutations in the primer and probe regions of the nucleocapsid gene amplicon and envelope gene amplicon accumulate over time. Some of these mutations correlate with the changes of detection pattern of viral targets of mRT-PCR. Our data highlight the significance of a continuous genetic divergence on a gene amplification-based assay, the value of the mRT-PCR detection pattern for complementing the clinical diagnosis of reinfection, and the potential for WGA and NGS to identify mutation hotspots throughout the entire viral genome to optimize the design of the PCR-based gene amplification assay.


Asunto(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , COVID-19/genética , Prueba de COVID-19 , Técnicas de Laboratorio Clínico/métodos , Humanos , Reacción en Cadena de la Polimerasa Multiplex , Pandemias , ARN Viral/análisis , ARN Viral/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , SARS-CoV-2/genética , Sensibilidad y Especificidad
13.
Small ; 16(41): e2002435, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32954651

RESUMEN

Infection with live-attenuated vaccines always inevitably induces side effects that reduce their safety. This study suggests a concept of magnetic virus produced by genetically modifying viral surfaces with Fe3 O4 nanoparticles (NPs) to control their tropisms. An iron-affinity peptide is designed to be displayed on the viral surface protein (VP1) of human enterovirus type 71 (EV71), a typical nonenveloped picornavirus, as the model. The modified EV71 can self-bind with Fe3 O4 NPs under physiological conditions, resulting in novel EV71-Fe3 O4 hybrid materials. This rationally engineered EV71 with Fe3 O4 retains its original biological infectivity, but its tropism can be precisely controlled by magnetism. Both in vitro and in vivo experiments demonstrate that EV71-Fe3 O4 can infect only a desired area within the limit of the applied magnetic field, which effectively reduces its pathological damage. More importantly, this characteristic of EV71 can be inherited due to the gene-induced coassembly of viruses and NPs. This achievement provides a proof of concept in virus vaccine improvement by a combination of gene modification and material incorporation, leading to great potential for biomedical developments.


Asunto(s)
Enterovirus , Nanopartículas , Humanos , Fenómenos Magnéticos
14.
Nanotechnology ; 31(31): 315601, 2020 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-32294640

RESUMEN

Lithium-sulfur batteries are considered as the next generation of energy storage systems because of their high theoretical specific capacity and energy density. Unfortunately, the sluggish reaction kinetics, weak adsorption toward to lithium polysulfides, and slow lithium ion diffusion impede the smooth electrochemical process, resulting in the lithium-sulfur batteries with the unsatisfactory cycling stability and rate performance. Since it is recognized that polar metal oxides and doped nitrogen in carbon materials have chemical interaction with lithium polysulfides, a nanostructured nitrogen-doped porous carbon/MoO2 composite is synthesized through a simple hydrothermal method by using graphene oxide nanoribbon and phosphomolybdic acid hydrate as precursors. The porous nanostructure promotes the charge and mass transport, while MoO2 nanoparticles immobilize lithium polysulfides via strong chemisorption and enhance the redox kinetics of polysulfides owing to the efficient catalytic activity in liquid-solid boundary. Consequently, the as-obtained nanostructured porous carbon/MoO2-based sulfur cathode exhibits low polarization, high initial discharge capacity (1403 mAh g-1 at 0.1 C), good rate capabilities (584 mAh g-1 at 4 C), and impressive cycling performance at 1 C (503 mAh g-1 after 500 cycles with capacity fade rate of 0.07% per cycle).

15.
Langmuir ; 35(24): 7650-7658, 2019 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-31063388

RESUMEN

In this study, we have prepared novel pyrrole-formaldehyde polymers through polymerizing pyrrole and formaldehyde in the mixture solvent of water and ethanol by using hydrochloric acid as a catalyst. The as-synthesized polymers possess a nitrogen content of 6.7 atom % and are composed of spherical particles with the diameter of approximately 1-3 µm. A series of nitrogen-doped porous carbons with high specific surface areas (680-2340 m2 g-1) were successfully obtained through the activation treatment of the polymer spheres. The porous properties and surface chemistry of the as-prepared porous carbons are tuned by choosing different activating agents and changing the activation temperature. The morphology, porous properties, and chemical composition of the obtained nitrogen-doped porous carbons are revealed by various characterization methods, such as scanning electron microscopy, nitrogen sorption measurement, and X-ray photoelectron spectroscopy. The as-prepared nitrogen-doped porous carbons as gas adsorbents display high carbon dioxide uptake capacities of 3.80-5.81 mmol g-1 at 273 K and 1.0 bar. They also show excellent carbon dioxide adsorption capacities (2.40-3.37 mmol g-1 at 1.0 bar) and good gas selectivities (CO2/N2 selectivities of 16.9-70.2) at 298 K.

16.
Molecules ; 24(18)2019 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-31514332

RESUMEN

Arbutin (also called ß-arbutin) is a natural product occurring in the leaves of a variety of different plants, the bearberries of the Ericaceae and Saxifragaceae families being prominent examples. It is a ß-glucoside derived from hydroquinone (HQ; 1,4-dihydroxybenzene). Arbutin has been identified in traditional Chinese folk medicines as having, inter alia, anti-microbial, anti-oxidant, and anti-inflammatory properties that useful in the treatment of different ailments including urinary diseases. Today, it is also used worldwide for the treatment of skin ailments by way of depigmenting, which means that arbutin is a component of many products in the cosmetics and healthcare industries. It is also relevant in the food industry. Hundreds of publications have appeared describing the isolation, structure determination, toxicology, synthesis, and biological properties of arbutin as well as the molecular mechanism of melanogenesis (tyrosinase inhibition). This review covers the most important aspects with special emphasis on the chemical and biocatalytic methods for the production of arbutin.


Asunto(s)
Arbutina/química , Arbutina/farmacología , Biocatálisis , Arbutina/biosíntesis , Arbutina/síntesis química , Estereoisomerismo , Especificidad por Sustrato
17.
Angew Chem Int Ed Engl ; 58(3): 764-768, 2019 01 14.
Artículo en Inglés | MEDLINE | ID: mdl-30511432

RESUMEN

Hydroquinone (HQ) is produced commercially from benzene by multi-step Hock-type processes with equivalent amounts of acetone as side-product. We describe an efficient biocatalytic alternative using the cytochrome P450-BM3 monooxygenase. Since the wildtype enzyme does not accept benzene, a semi-rational protein engineering strategy was developed. Highly active mutants were obtained which transform benzene in a one-pot sequence first into phenol and then regioselectively into HQ without any overoxidation. A computational study shows that the chemoselective oxidation of phenol by the P450-BM3 variant A82F/A328F leads to the regioselective formation of an epoxide intermediate at the C3=C4 double bond, which departs from the binding pocket and then undergoes fragmentation in aqueous medium with exclusive formation of HQ. As a practical application, an E. coli designer cell system was constructed, which enables the cascade transformation of benzene into the natural product arbutin, which has anti-inflammatory and anti-bacterial activities.


Asunto(s)
Benceno/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Hidroquinonas/metabolismo , Sistema Enzimático del Citocromo P-450/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Glucosiltransferasas/genética , Glucosiltransferasas/metabolismo , Hidroxilación , Modelos Moleculares , Oxidación-Reducción , Ingeniería de Proteínas , Rauwolfia/genética , Rauwolfia/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
18.
Arch Virol ; 162(5): 1311-1318, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28155195

RESUMEN

Respiratory viruses are recognized as serious causes of morbidity and mortality in lower respiratory tract infections in patients. Isothermal amplification assays are increasingly used in their detection because of their rapidity, simplicity and cost-effectiveness, when compared to traditional molecular diagnostic methods. However, systematic assessment of these assays in the clinical settings is rarely reported. MEDLINE (Pubmed) searches were done analysing subject headings and words in the abstract related to isothermal amplification assay and virus. Selected loop-mediated isothermal amplification assays (LAMP) for respiratory syncytial virus (RSV), human metapneumovirus (HMPV) and adenovirus (ADV) as well as a reverse transcription genome exponential amplification reaction assay (GEAR) for human rhinovirus (HRV) were clinically evaluated in a head to head comparison against a two-tube multiplex reverse transcription-PCR (RT-PCR) assay (two-tube assay) using 634 respiratory specimens from children with pneumonia from different regions in China. Discrepant results between isothermal amplification assays and the two-tube assay were resolved by sequencing. A comparison of sensitivities of each selected isothermal amplification assay among province, gender, and age groups was also analyzed. A total of 634 respiratory specimens selected from Hebei Province children's hospital and Hunan Provincial Center for Disease Control and Prevention were tested. The overall detection rate (number of positive specimens/total specimens) for viruses tested by Reverse transcription (RT)-LAMP/LAMP/RT-GEAR was 35.9% while the detection rate was 46.2% by the two-tube assay. The sensitivity of each isothermal amplification assay was 88.4%, 74.3%, 100% and 73.6% for RSV, HMPV, ADV and HRV, respectively. No false positives were found in isothermal amplification assays. All the discrepant negative results by isothermal amplification assays were confirmed false negatives by sequencing. The LAMP assay for ADV showed significant consistency with the two-tube assay. A higher sensitivity of RSV detection was found in Hunan Province than in Hebei Province (P = 0.01). Among different age groups, a higher sensitivity of RSV detection was also found in children older than 1 year, when compared to children less than 1 year (P = 0.01). The clinical performance of the selected isothermal amplification assays for different viruses varies. Multiple-center assessment is critical to evaluate isothermal amplification assays, especially for RNA viruses, for their broad use in clinical hospital. The selected LAMP assay for the detection of ADV is reliable and has great potential for use in clinics; however, the sensitivities of the LAMP/GEAR assays for the detection of RSV, HMPV and HRV need to be further improved to meet clinical requirements, although a statistical difference in sensitivity was only found for the selected LAMP assay for RSV.


Asunto(s)
Adenoviridae/genética , Metapneumovirus/genética , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , Neumonía Viral/diagnóstico , Virus Sincitial Respiratorio Humano/genética , Rhinovirus/genética , Infecciones por Adenoviridae/diagnóstico , Infecciones por Adenoviridae/virología , Preescolar , China , Femenino , Humanos , Lactante , Masculino , Reacción en Cadena de la Polimerasa Multiplex , Infecciones por Paramyxoviridae/diagnóstico , Infecciones por Paramyxoviridae/virología , Infecciones por Picornaviridae/diagnóstico , Infecciones por Picornaviridae/virología , Neumonía Viral/virología , Infecciones por Virus Sincitial Respiratorio/diagnóstico , Infecciones por Virus Sincitial Respiratorio/virología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transcripción Reversa
19.
Nanotechnology ; 28(49): 495701, 2017 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-28990580

RESUMEN

Lithium-sulfur batteries have attracted great concern because of the high theoretical capacity of sulfur (1675 mA h g-1). However, the poor electrical conductivity and volumetric expansion of sulfur along with the dissolution of lithium polysulfides largely limit their practical application. In this study, nitrogen-doped graphene aerogel (NGA) with high nitrogen content and porosity is used as a host for the impregnation of sulfur. The effects of sulfur impregnation on the specific surface area, pore volume, and microstructure of NGA supported sulfur composite (S@NGA) are well investigated. Furthermore, NGA is also processed into a NGA film, which is sandwiched between a separator and S@NGA cathode. The lithium-sulfur battery with such a configuration delivers a high reversible capacity of 1514 mA h g-1 at 0.1 C, excellent rate performance (822 mA h g-1 at 2.0 C), and good cycling stability (946 mA h g-1 at 0.5 C even after 100 cycles). The enhanced electrochemical performance can be ascribed to the introduction of the NGA interlayer, the unique interconnected porous structure, and strong interaction between the three-dimensional nitrogen-doped graphene network and the homogeneously dispersed sulfur and/or lithium polysulfides.

20.
Angew Chem Int Ed Engl ; 56(42): 12908-12912, 2017 10 09.
Artículo en Inglés | MEDLINE | ID: mdl-28722241

RESUMEN

Although the circulation of avian influenza viruses in humans is limited, they can be transmitted from Aves (birds) to humans, representing a great challenge. Herein, we suggest that influenza viruses from Aves might exist in a mineralized state owing to the high calcium concentrations in the avian intestine. Using two typical influenza viruses as examples, we demonstrate that these viruses can self-mineralize in simulated avian intestinal fluid, resulting in egg-like virus-mineral structured composites. The mineralized viruses are more robust, with enhanced infectivity and thermostability. More importantly, the mineral exterior of mineralized viruses can alter their cell internalization, expanding the possible tropisms. The discovery of a mineralized state of influenza viruses highlights the integration of nanomaterials and viruses in the environment, which provides a new understanding of avian influenza infection and its control.


Asunto(s)
Subtipo H9N2 del Virus de la Influenza A/fisiología , Minerales/química , Células A549 , Animales , Aves/crecimiento & desarrollo , Calcio/química , Humanos , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/fisiología , Subtipo H9N2 del Virus de la Influenza A/química , Intestinos/virología , Pulmón/virología , Ratones , Microscopía Electrónica de Transmisión , Óvulo/virología , ARN Viral/metabolismo , Internalización del Virus
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