Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 66
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Carbohydr Polym ; 251: 117094, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33142632

RESUMO

Nanocellulose has gained increasing attention due to its excellent properties and wide application prospect. However, fast and low-waste preparation of nanocellulose is still challenging. Here, a time-saving and low-cost chemi-mechanical method was proposed to prepare cellulose nanocrystals (D-CNCs) and cellulose nanofibers (D-CNFs) by dilute sulfuric acid hydrolysis and the homogenization of the un-hydrolyzed cellulose residues, respectively. After hydrolyzed by 0.3 wt% sulfuric acid at 160 °C for 2 h, the diameter and length distribution of the obtained D-CNCs were 16 ∼ 45 nm and 150 ∼ 600 nm, respectively. The yield of D-CNCs and D-CNFs reached to 15.78 % and 69.11 %. The thermostability of D-CNCs was more superior to CNCs manufactured by 64 wt% sulfuric acid. In conclusion, this approach offers a promising strategy for high yield of nanocellulose due to its easy operation and low pollution.

2.
Carbohydr Polym ; 251: 117117, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33142652

RESUMO

The development of biopolymer films is crucial for the replacement of conventional plastics. Tremendous effort is made to improve their performances by introducing biopolymers through the film manufacturing process. Herein, a sandwich-architectured film was proposed to efficiently improve the adhesion between the PS and PLA layers by using octenyl succinic anhydride-modified pea starch (OMPS) layer as the interlayer, leading to a highly mechanically enhanced interpenetrating network. Accordingly, the properties of the films were enhanced due to the synergism effect of sandwich architecture. In particular, the WVP value of the sandwich-architectured films (0.25 ∼ 0.89×10-10g·m-1·s-1·Pa-1) decreased more than 7-fold compared with the OMPS20 film, and the OP value of the sandwich-architectured films (0.256 ∼ 1.229×10-12cm3·m·m-2·s-1·Pa-1) decreased more than 10-fold in comparison to the PLA film. Benefitting from the characteristics investigated above, the films exhibited a favorable effect on strawberry storage. Overall, the fabricated eco-friendly sandwich-architectured films have shown great potential for biodegradable packaging applications.

3.
Biosens Bioelectron ; : 112873, 2020 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-33298338

RESUMO

Herein, a high-efficiency photoactive material, hollow ZnIn2S4 nanocages (ZIS-HNCs) composed of ultrathin nanosheets were creatively synthesized via a metal-organic framework (MOF) derived solvothermal method. It had been specified the underlying mechanism of the ZIS-HNCs evolution under the MOF templated surface. Subsequently, the obtained ZIS-HNCs combined with annealing TiO2 modified electrode (ZIS-HNCs@TiO2), and the ZIS-HNCs@TiO2 exhibited intense transient photocurrent. The enhanced photocurrent signal benefited from the multiple light capture effect of ZIS-HNCs, ultrathin nanosheet subunits of ZIS-HNCs, and typical type Ⅱ heterojunction, which could effectively retard the photoexcited electron-hole pairs recombination, and accelerated charge separation and transfer. Taking antibiotic lincomycin (Lin) as a model, a signal-off photoelectrochemical (PEC) aptasensor based on the ZIS-HNCs@TiO2 was established and manifested a high sensitive detection for Lin with a linear response range from 0.0001 to 0.1 nM as well as an ultralow detection limit of 0.084 pM. Additionally, the proposed PEC aptasensor showed acceptable stability and remarkable selectivity. Therefore, this study provides a promising strategy to design nanomaterials with superior photoelectric activity for PEC sensing applications.

4.
Sci Rep ; 10(1): 18870, 2020 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-33139761

RESUMO

Despite increasing evidence that antibiotic resistant pathogens are shared among humans and animals, the diversity, abundance and patterns of spread of antibiotic resistance genes (ARGs) in wildlife remains unclear. We identified 194 ARGs associated with phenotypic resistance to 13 types of antibiotic in meta-transcriptomic data generated from a broad range of lower vertebrates residing in both terrestrial and aquatic habitats. These ARGs, confirmed by PCR, included those that shared high sequence similarity to clinical isolates of public health concern. Notably, the lower vertebrate resistome varied by ecological niche of the host sampled. The resistomes in marine fish shared high similarity and were characterized by very high abundance, distinct from that observed in other habitats. An assessment of ARG mobility found that ARGs in marine fish were frequently co-localized with mobile elements, indicating that they were likely spread by horizontal gene transfer. Together, these data reveal the remarkable diversity and transcriptional levels of ARGs in lower vertebrates, and suggest that these wildlife species might play an important role in the global spread of ARGs.

5.
Carbohydr Polym ; 249: 116827, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32933674

RESUMO

To better understand the system and conversion of cellulose allomorphs, cellulose III nanocrystals (CNC-III) were used to investigate the crystalline stability of cellulose III in the hydrothermal condition and a lower concentrated NaOH-water system. It was shown that H2O or alkali played an important role in the process of polymorphic transformation. The CNC-III allomorph turned back to cellulose I with an extremely low crystallinity (∼4.18 %) during hydrothermal process at 90-95 °C, or cellulose II when the temperature excessed boiling point (≥100 °C). Furthermore, CNC-III could be rapidly dissolved in an aqueous NaOH (∼7 wt.%) without a pre-cooled treatment to obtain its stable solution. Afterwards, cellulose II with a steady average crystallite size (∼34) was acquired after the regeneration process via dialysis with distilled water. The polymorphic transformation was also analyzed by X-ray diffraction (XRD), solid-state 13C nuclear magnetic resonance (13C NMR).

6.
Carbohydr Polym ; 247: 116721, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32829845

RESUMO

Nanofibrillated cellulose (NFC) is becoming popular in the field of anti-counterfeiting material due to its favorable biocompatibility, renewability, and easy modification properties, which give it great potentials as carrier of carbon quantum dots (CQDs). Herein, we report an effective method to fabricate Yb and Er doped CQDs grafted onto dialdehyde NFC (DANFC). Owning to special rheological properties of NFC, a waterborne fluorescent dual anti-counterfeiting ink was rationally designed and successfully prepared by adding NFC to waterborne ink to form a stable network structure and increase the thixotropy and yield stress. The resulting CQDs exhibited both photoluminescence (PL) and up-conversion luminescence (UCPL), emitting blue and green fluorescence at excitation wavelengths of 370 and 980 nm, respectively. The study provides a novel method to prepare the waterborne fluorescent dual anti-counterfeiting ink based on Yb and Er doped CQDs/DANFC composites, which provides a reference for its application in printing and packaging industry.

7.
Carbohydr Polym ; 239: 116226, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32414452

RESUMO

Due to the nanoscale and the same chemical structure to cellulosic fibers, it is difficult to directly observe the distribution of CNFs in paper sheets. Herein, dye-labeled CNFs were introduced to analyze the distribution of CNFs in paper handsheets. The dye was successfully loaded on CNFs through hydrogen bonding with an environmentally friendly method. Dye-labeled CNFs were mixed with four types of pulps with different beating degrees to form paper handsheets. The results showed that with the beating degree increasing, the colorimetric values of wire side and felt side were different among the four types of paper, which indicated that distributions of CNFs in the Z-direction of papers were not uniform. The study demonstrated that the dye-labeled CNFs methods is an effective way to analyze the distribution of CNFs in paper-based materials.

8.
Virus Evol ; 6(1): veaa020, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32296543

RESUMO

Epizootic pathogens pose a major threat to many wildlife species, particularly in the context of rapidly changing environments. Pangolins (order Pholidota) are highly threatened mammals, in large part due to the trade in illegal wildlife. During July to August 2018 four sick wild pangolins (three Manis javanica and one Manis pentadactyla) exhibiting a variety of clinical symptoms were rescued by the Jinhua Wildlife Protection Station in Zhejiang province, China. Although three of these animals died, fortunately one recovered after 2 weeks of symptomatic treatment. Using meta-transcriptomics combined with reverse transcription polymerase chain reaction (RT-PCR), we identified two novel RNA viruses in two of the dead pangolins. Genomic analysis revealed that these viruses were most closely related to pestiviruses and coltiviruses, although still highly genetically distinct, with more than 48 and 25 per cent sequence divergence at the amino acid level, respectively. We named these Dongyang pangolin virus (DYPV) and Lishui pangolin virus (LSPV) based on the sampling site and hosts. Although coltiviruses (LSPV) are known to be transmitted by ticks, we found no evidence of LSPV in ticks sampled close to where the pangolins were collected. In addition, although DYPV was present in nymph ticks (Amblyomma javanense) collected from a diseased pangolin, they were not found in the local tick population. Epidemiological investigation revealed that both novel viruses might have been imported following the illegal international trade of pangolins. Hence, these data indicate that illegal wildlife trafficking not only threatens the status of pangolin populations, but may also spread epizootic pathogens.

9.
Carbohydr Polym ; 230: 115631, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31887916

RESUMO

Nano-fibrillated celluloses (NFCs) were separated from bleached softwood kraft pulp. Through the periodate oxidation method, 2,3-dialdehyde nano-fibrillated celluloses (DNFCs) with varied aldehyde content were prepared. The high aldehyde content, large specific surface area and high surface charge density of DNFCs benefited the adsorbing of Cu (II). The adsorption kinetics and isotherms presented good correlations with the Pseudo-second-order model and Freundlich model, respectively. Both physical and chemical adsorptions existed in the Cu (II) adsorption by DNFCs, while chemisorption was the rate-limiting step. The adsorption thermodynamic parameters Gibbs free energy change (ΔG), enthalpy change (ΔH) and entropy change (ΔS) were also investigated. This study provides theoretical support for applying DNFCs to remove metal ions from aqueous solutions.

10.
J Hand Surg Am ; 45(5): 454.e1-454.e8, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31810540

RESUMO

PURPOSE: Finger pulp resurfacing is a challenging reconstructive problem. This article introduces sensory reconstruction of finger pulp defects using an innervated distally-based neurovascular flap raised from the dorsum of the thumb. METHODS: From May 2015 to May 2017, the innervated distally-based neurovascular flap was used in 36 patients. The mean age at surgery was 37 years (range, 18-61 years). All patients were assessed using the total active motion (TAM) scoring system of the American Society for Surgery of the Hand. The sensitivity of the flap was tested using static 2-point discrimination. RESULTS: Full flap survival was achieved in 35 cases. Partial necrosis at the distal margin of the flap was observed in 1 case. At the final follow-up (mean, 20 months; range, 18-23 months), the mean TAM of the thumb was 206° (range, 188°-238°), including 8 excellent and 28 good results. The mean TAM of fingers was 266° (range, 251°-282°), including 4 excellent and 32 good results. The mean value of static 2-point discrimination was 5 mm (range, 4-7 mm) in the flap, including 31 excellent and 5 good results. CONCLUSIONS: The innervated distally-based neurovascular flap raised from the dorsum of the thumb is a reliable alternative for sensory reconstruction of finger pulp defects. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

11.
Genes Dev ; 33(23-24): 1718-1738, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31727771

RESUMO

More than 90% of small cell lung cancers (SCLCs) harbor loss-of-function mutations in the tumor suppressor gene RB1 The canonical function of the RB1 gene product, pRB, is to repress the E2F transcription factor family, but pRB also functions to regulate cellular differentiation in part through its binding to the histone demethylase KDM5A (also known as RBP2 or JARID1A). We show that KDM5A promotes SCLC proliferation and SCLC's neuroendocrine differentiation phenotype in part by sustaining expression of the neuroendocrine transcription factor ASCL1. Mechanistically, we found that KDM5A sustains ASCL1 levels and neuroendocrine differentiation by repressing NOTCH2 and NOTCH target genes. To test the role of KDM5A in SCLC tumorigenesis in vivo, we developed a CRISPR/Cas9-based mouse model of SCLC by delivering an adenovirus (or an adeno-associated virus [AAV]) that expresses Cre recombinase and sgRNAs targeting Rb1, Tp53, and Rbl2 into the lungs of Lox-Stop-Lox Cas9 mice. Coinclusion of a KDM5A sgRNA decreased SCLC tumorigenesis and metastasis, and the SCLCs that formed despite the absence of KDM5A had higher NOTCH activity compared to KDM5A +/+ SCLCs. This work establishes a role for KDM5A in SCLC tumorigenesis and suggests that KDM5 inhibitors should be explored as treatments for SCLC.


Assuntos
Diferenciação Celular/genética , Células Neuroendócrinas/citologia , Receptores Notch/fisiologia , Proteína 2 de Ligação ao Retinoblastoma/metabolismo , Transdução de Sinais/genética , Carcinoma de Pequenas Células do Pulmão/enzimologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Linhagem Celular , Transformação Celular Neoplásica/genética , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica/genética , Histona Desmetilases/metabolismo , Humanos , Técnicas In Vitro , Camundongos , Células Neuroendócrinas/patologia , Carcinoma de Pequenas Células do Pulmão/fisiopatologia
12.
ACS Appl Mater Interfaces ; 11(42): 39088-39099, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31566951

RESUMO

To date, various electronic devices have been strategically fabricated, and simultaneous realization of high electrical conductivity, sensing property, and heat-conducting property by a simple, efficient, and accurate approach is significant but still challenging. Here, cellulosic fiber supported 3D interconnected silver nanowire (AgNW) networks with hierarchical structures are rationally designed to achieve excellent electrical conductivity and superior thermal dispersion capability. In particular, thermal annealing at the junctions enables both phonon and electron transfer as well as impedes interfacial slippage. In the current study, the AgNW/cellulosic paper with the low Ag content (1.55 wt %) exhibits a low sheet resistance of 0.51 Ω sq-1. More importantly, the AgNW/cellulosic paper-based flexible strain sensor has been reasonably developed, which can be applied to monitor various microstructural changes and human motions with high sensitivity and robust stability (fast response/relaxation time of ∼100 ms and high stability >2000 bending-stretching cycles). The AgNW/cellulosic paper-based device also displays efficient thermal dispersion property, which offers exciting opportunities for thermal management application. Furthermore, the obtained hybrid paper exhibits superior heat dispersion capacity for thermal management devices. Overall, uniform dispersion and 3D interconnected junctions of AgNW among the fibers inside the cellulosic papers lead to the combination of high mechanical strength, highly efficient electrical conductivity, and ultrahigh heat dispersion property. The AgNW/cellulosic paper has promising potentials in the flexible and wearable sensing elements, thermal management materials, and artificial intelligence devices.

13.
Biosens Bioelectron ; 143: 111627, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31476601

RESUMO

In traditional electrochemiluminescence (ECL) analysis, gold nanomaterials are commonly used as a tool for signal amplification and linking antibodies due to their good electrical conductivity and biocompatibility. Here, we found that multitipped gold nanoparticles-gold nanoflowers (AuNFs) as coreactant accelerator have good catalytic activity for the reduction of dissolved oxygen (O2) to hydrogen peroxide (H2O2) using tris (hydroxymethyl) aminomethane (Tris) as electron donor. Based on this, a new enzyme-free and label-free ECL immunosensor have been constructed for the detection of α-fetoprotein (AFP). In this system, due to the unique geometric and spatial effects of AuNFs, the dissolved O2 as endogenous coreactant was catalyzed by AuNFs to produce H2O2 using Tris as an electron donor. The in situ generated H2O2 can more efficiently produce various electrogenerated reactive oxygen species (ROSs) as the important intermediates on the electrode surface. Then, oxidation of luminol reacts with ROSs significantly amplifies the luminol ECL signal. Under optimal experimental conditions, the proposed ECL immunosensor was able to detect the AFP concentration from 0.01 to 100 ng mL-1, with a low detection limit of 3.4 pg mL-1 (S/N = 3). In addition, the prepared ITO-based sensor is similar to a micro-test chip and convenient to use, thus making it suitable for clinical use as a disposable device in point-of-care tests (POCTs).


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , alfa-Fetoproteínas/isolamento & purificação , Glucose Oxidase/química , Ouro/química , Grafite/química , Humanos , Peróxido de Hidrogênio/química , Medições Luminescentes , Luminol/química , Nanopartículas Metálicas/química , alfa-Fetoproteínas/química
14.
Carbohydr Polym ; 223: 115052, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31427013

RESUMO

Enzymatic pretreatment as an eco-friendly strategy has offered potential benefits in disintegrating cellulosic fibers into fibrils but limited by its high price. In this study, endoglucanase recycling was investigated in order to reduce endoglucanase expanses. Significant DP reduction can be achieved from 50.88% to 76.96% only by recycling liquid which included free endoglucanase. In the presence of fresh endoglucanase, no more pronounced reduction of DP was observed in all recycling rounds attributing to competitive adsorption between fresh and recycled endoglucanase. Fresh endoglucanase preferentially occupied active sites on cellulose surface, hydrolyzed amorphous region, and followed by degrading fibrils to saccharides together with recycled endoglucanase. This hypothesis was evidenced by increase of saccharides concentration when fresh endoglucanase was added. This study aims to provide theoretical support to decrease endoglucanase cost for deconstruction of fibers to fibrils in industrial manufacture.


Assuntos
Celulase/química , Celulose/química , Adsorção , Química Verde/métodos , Hidrólise , Peso Molecular , Reciclagem
15.
Bioresour Technol ; 282: 228-235, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30870688

RESUMO

Camellia Oleifera Shell (COS) is a kind of renewable lignocellulose resource and contains abundant hemicelluloses. In this work, the hemicelluloses in COS were extracted by alkali treatment and precipitated by ethanol with different concentration. Thermal pyrolysis kinetics of COS hemicelluloses were investigated using a thermogravimetric analyzer at the heating rates of 5, 10, and 20 °C/min based on Coats-Redfern, Flynn-Wall-Ozawa (FWO), and Kissinger-Akahira-Sunose (KAS) model. The results showed that the best fitting thermal pyrolysis mechanism of COS hemicelluloses was one-dimensional diffusion reaction analyzed by Coats-Redfern model. The activation energies of COS hemicelluloses ranged from 175.07 to 247.87 kJ·mol-1 and from 174.74 to 252.50 kJ·mol-1 calculated by FWO and KAS, respectively. The thermal stabilities of COS hemicelluloses were enhanced with the precipitated ethanol concentration increasing, and reflected by thermodynamic parameters ΔH, ΔG and ΔS. This study may provide basic theoretical supports for the thermochemical conversion of COS hemicelluloses.


Assuntos
Camellia/química , Polissacarídeos/química , Cinética , Polissacarídeos/isolamento & purificação , Pirólise , Termodinâmica
16.
Biosens Bioelectron ; 133: 125-132, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30921628

RESUMO

Herein, novel photoactive materials, MOF-derived porous hollow carbon nanobubbles@ZnCdS multi-shelled dodecahedral cages (C@ZnCdS MSDCs), were synthesized via continuous chemical etching, sulfurization, cation-exchange and calcination strategies. Due to the synergistic effect between the porous shells and the carbon-layer coating, C@ZnCdS MSDCs displayed superior photoelectrochemical (PEC) performance. The synthesized C@ZnCdS MSDCs were assembled onto TiO2 modified ITO electrodes to form a type-II heterostructures. Then, Au nanoparticles (NPs) were deposited on the surface of ITO/TiO2/C@ZnCdS MSDCs. Benefiting from the unique structure and performance merits of photoactive materials, a label-free PEC sensing platform based on ITO/TiO2/C@ZnCdS MSDCs/Au was successfully constructed for CEA detection. Under optimal conditions, the PEC biosensor exhibited a wide linear range (0.00005-500 ng mL-1) and low detection limit (2.28 fg mL-1). The proposed PEC biosensor also showed good stability, specificity, reproducibility and acceptability in human serum. The prepared C@ZnCdS MSDCs would be a promising photoactive material for PEC biosensors. Most importantly, this work opens up new horizons for the application of MOFs-derived hollow carbon materials in sensing.


Assuntos
Técnicas Biossensoriais , Antígeno Carcinoembrionário/isolamento & purificação , Técnicas Eletroquímicas , Nanopartículas Metálicas/química , Cádmio/química , Antígeno Carcinoembrionário/sangue , Ouro/química , Humanos , Luz , Limite de Detecção , Porosidade , Titânio/química , Zinco/química
17.
Carbohydr Polym ; 207: 44-51, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30600026

RESUMO

Hornification are usually occurred in cellulosic fibers and even in nanocellulose fibrils during dehydration process but their mesoscopic structural changes is not fully understood. Here we investigated the structural features of cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNF) with different solid content. In order to avoid the effect of drying, liquid AFM mode was carried out in this work. The different water contents of nanocellulose were quantified by Differential Scanning Calorimetry (DSC). We showed evidence of extreme growth in radial direction in the redispersed nanocelluloses, analyzed by statistics of contours from microscopy images. The amount of free water, freezing bound water, and non-freezing bound water decreased gradually during water evaporation and were completely removed in sequence. In addition, the hydroxyl accessibility of both redispersed CNCs and CNF were reduced by 83.33% and 81.96% via evaluating the uptake of fluorescent dyes.


Assuntos
Celulose/química , Dessecação , Nanofibras/química , Nanopartículas/química , Água/química , Coloides/química , Ligação de Hidrogênio , Pinus/química , Eletricidade Estática
18.
Sci Total Environ ; 661: 63-74, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30665133

RESUMO

Many rivers are facing human-induced system regime shifts that have great environmental, ecological and social implications, necessitating an increasing need to quantify the human influence on sediment properties and their impacts on the source-to-sink system of marginal seas. The Huanghe and Changjiang Rivers have experienced a dramatic reduction in sediment flux in recent decades, typifying the human influence on sediment properties of global large rivers. Sediment samples from the two rivers were analyzed to obtain grain size, magnetic and geochemical data. The results show a large difference in sediment properties between pre- and post-dam periods. We applied a discrepancy factor to re-examine the magnetic and geochemical tracers that were previously used in the two rivers. The discrepancy factors of most magnetic and geochemical tracers in the mud-sized sediments of the two rivers increased by an average of about 109% after dam construction. This suggests that human-induced changes in sediment properties have greatly improved the discriminatory ability between the sediments from the two rivers. The results also raise the uncertainty of using previous tracers to distinguish between sediments from the two rivers after damming. Furthermore, significant changes in sediment properties that happened in a relatively short time may provide future geological time markers for sedimentary records with a temporal resolution of 100-101 years. For marine environments, an approach for identifying sediment sources based on multiple independent optimum tracers is also proposed, with composite magnetic (SIRM vs. HIRM) and geochemical (Na2O vs. Zn) tracers being considered. The results of this work can advance our knowledge of how human activities alter river systems, and identify a sustainable development model under system regime shifts for areas of high-intensity human activity.

19.
PLoS Genet ; 14(9): e1007679, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30256787

RESUMO

The mechanistic target of rapamycin (mTOR) is an established therapeutic target in renal cell carcinoma (RCC). Mechanisms of secondary resistance to rapalog therapy in RCC have not been studied previously. We identified six patients with metastatic RCC who initially responded to mTOR inhibitor therapy and then progressed, and had pre-treatment and post-treatment tumor samples available for analysis. We performed deep whole exome sequencing on the paired tumor samples and a blood sample. Sequence data was analyzed using Mutect, CapSeg, Absolute, and Phylogic to identify mutations, copy number changes, and their changes over time. We also performed in vitro functional assays on PBRM1 in RCC cell lines. Five patients had clear cell and one had chromophobe RCC. 434 somatic mutations in 416 genes were identified in the 12 tumor samples. 201 (46%) of mutations were clonal in both samples while 129 (30%) were acquired in the post-treatment samples. Tumor heterogeneity or sampling issues are likely to account for some mutations that were acquired in the post-treatment samples. Three samples had mutations in TSC1; one in PTEN; and none in MTOR. PBRM1 was the only gene in which mutations were acquired in more than one post-treatment sample. We examined the effect of PBRM1 loss in multiple RCC cell lines, and could not identify any effect on rapalog sensitivity in in vitro culture assays. We conclude that mTOR pathway gene mutations did not contribute to rapalog resistance development in these six patients with advanced RCC. Furthermore, mechanisms of resistance to rapalogs in RCC remain unclear and our results suggest that PBRM1 loss may contribute to sensitivity through complex transcriptional effects.


Assuntos
Antineoplásicos/farmacologia , Carcinoma de Células Renais/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Renais/tratamento farmacológico , Proteínas Nucleares/genética , Inibidores de Proteínas Quinases/farmacologia , Fatores de Transcrição/genética , Adulto , Idoso , Antineoplásicos/uso terapêutico , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , Proteínas de Ligação a DNA , Progressão da Doença , Epigênese Genética , Everolimo/farmacologia , Everolimo/uso terapêutico , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Heterogeneidade Genética/efeitos dos fármacos , Humanos , Neoplasias Renais/genética , Neoplasias Renais/patologia , Masculino , Pessoa de Meia-Idade , Mutação , Inibidores de Proteínas Quinases/uso terapêutico , Transdução de Sinais/genética , Sirolimo/análogos & derivados , Sirolimo/farmacologia , Sirolimo/uso terapêutico , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/metabolismo , Sequenciamento Completo do Exoma
20.
Talanta ; 188: 58-65, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30029416

RESUMO

In this study,we proposed a triangular silver nanosheets (Tri-SNSs)-layered, Chitosan (CS)-supported three-dimensional of reduced graphene oxide (3D-ERGO) electrochemiluminescence (ECL) biosensing platform using self-designed dual-Ru(bpy)32+ scDNA (Ru2-DNA) as capture probe for ECL biosensing of single-chain DNA (scDNA). Based on the different affinity with scDNA and double chain DNA (dcDNA), the biosensor is designed to recognize the target DNA (t-DNA), which leads to the desorption of a hybrid molecule from the surface of the biosensor, further removing the Ru2-DNA and inhibiting the ECL. Analytical results clearly showed that the electrochemical and ECL behaviors of proposed biosensing platform on the glassy carbon electrode (GCE) exhibited outstanding performance, which was due to large specific surface area, high carrier mobility and strong π-π non-covalent attraction toward single-chain DNA (scDNA) of the stable 3D platform, and ECL amplification of Tri-SNSs. Besides, based on such a system, this strategy can effectively identify full match and mismatched target DNA (M-DNA) with a wide concentration range beyond 7 orders of magnitude and detection limit down to 16.2 aM. Therefore, the 3D biosensing strategy shows potential for the application of bioassays.


Assuntos
Técnicas Biossensoriais/métodos , DNA de Cadeia Simples/análise , Técnicas Eletroquímicas/métodos , Grafite/química , Nanoestruturas/química , Prata/química , 2,2'-Dipiridil/análogos & derivados , 2,2'-Dipiridil/química , Quitosana/química , Complexos de Coordenação/química , DNA de Cadeia Simples/química , Eletrodos , Limite de Detecção , Luminescência , Medições Luminescentes/métodos , Hibridização de Ácido Nucleico , Óxidos/química , Reprodutibilidade dos Testes
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA