Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
J Toxicol Environ Health A ; 87(10): 421-427, 2024 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-38551405

RESUMO

Vascular dementia (VD) a heterogenous group of brain disorders in which cognitive impairment is attributable to vascular risk factors and cerebrovascular disease. A common phenomenon in VD is a dysfunctional cerebral regulatory mechanism associated with insufficient cerebral blood flow, ischemia and hypoxia. Under hypoxic conditions oxygen supply to the brain results in neuronal death leading to neurodegenerative diseases including Alzheimer's (AD) and VD. In conditions of hypoxia and low oxygen perfusion, expression of hypoxia-inducible factor 1 alpha (HIF-1α) increases under conditions of low oxygen and low perfusion associated with upregulation of expression of hypoxia-upregulated mitochondrial movement regulator (HUMMR), which promotes anterograde mitochondrial transport by binding with trafficking protein kinesin 2 (TRAK2). Schisandrin B (Sch B) an active component derived from Chinese herb Wuweizi prevented ß-amyloid protein induced morphological alterations and cell death using a SH-SY5Y neuronal cells considered an AD model. It was thus of interest to determine whether Sch B might also alleviate VD using a rat bilateral common carotid artery occlusion (BCAO) dementia model. The aim of this study was to examine the effects of Sch B in BCAO on cognitive functions such as Morris water maze test and underlying mechanisms involving expression of HIF-1α, TRAK2, and HUMMR levels. The results showed that Sch B improved learning and memory function of rats with VD and exerted a protective effect on the hippocampus by inhibition of protein expression of HIF-1α, TRAK2, and HUMMR factors. Evidence indicates that Sch B may be considered as an alternative in VD treatment.


Assuntos
Demência Vascular , Lignanas , Neuroblastoma , Compostos Policíclicos , Ratos , Humanos , Animais , Demência Vascular/tratamento farmacológico , Demência Vascular/etiologia , Demência Vascular/metabolismo , Aprendizagem em Labirinto/fisiologia , Hipóxia , Cognição , Hipocampo , Oxigênio/farmacologia , Ciclo-Octanos
2.
Anal Bioanal Chem ; 415(20): 5011-5021, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37341783

RESUMO

A thermal-sensitive molecularly imprinted optosensing probe based on fluorescent advanced glycation end products (AGEs) was prepared by one-pot hydrothermal synthesis. Carbon dots (CDs) derived from fluorescent AGEs were used as the luminous centers, while molecularly imprinted polymers (MIPs) were wrapped outside of the CDs to form specific target recognition sites to highly selectively adsorb the intermediate product of AGEs of 3-deoxyglucosone (3-DG). Thermosensitive N-isopropylacrylamide (NIPAM) was combined with acrylamide (AM) as co-functional monomers, and ethylene glycol dimethacrylate (EGDMA) was chosen as a cross-linker for targeting identification and detection of 3-DG. Under optimal conditions, the fluorescence of MIPs could be gradually quenched with the adsorption of 3-DG on the surface of MIPs in the linear range of 1-160 µg/L, and the detection limit was 0.31 µg/L. The spiked recoveries of MIPs ranged from 82.97 to 109.94% in two milk samples, and the relative standard deviations were all less than 1.8%. In addition, the inhibition rate for non-fluorescent AGEs of pyrraline (PRL) was 23% by adsorbing 3-DG in the simulated milk system of casein and D-glucose, indicating that temperature-responsive MIPs not only could detect the dicarbonyl compound 3-DG quickly and sensitively, but also had an excellent inhibitory effect on AGEs.


Assuntos
Impressão Molecular , Polímeros , Corantes Fluorescentes , Carbono , Produtos Finais de Glicação Avançada
3.
Mikrochim Acta ; 190(3): 88, 2023 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-36773114

RESUMO

A novel and facile method was proposed for preparation of red emissive N-doped carbon dots encapsulated within molecularly imprinted polymers (RNCDs@MIPs) using a one-pot room-temperature reverse microemulsion polymerization. RNCDs used citric acid and urea as carbon and nitrogen sources by one-step solvothermal synthesis with the optimum emission of 620 nm. Unique optical properties of RNCDs coupled with high selective MIPs make the RNCDs@MIPs conjugate capable to adsorb specific targets of pyrraline (PRL), such a binding event was then transduced to quench fluorescence response signal of the RNCDs. RNCDs@MIPs for PRL showed linearity from 0.1 to 40 µg/L, with a detection limit of 65 ng/L. The RNCDs@MIPs exhibited a good reproducibility of 4.67% obtained from four times of rebinding for PRL. The optosensing probe was successfully applied to the detection of PRL in fatty foods with the spiked recovery of 85.93-106.96%.


Assuntos
Impressão Molecular , Pontos Quânticos , Carbono/química , Polímeros Molecularmente Impressos , Impressão Molecular/métodos , Polímeros/química , Reprodutibilidade dos Testes , Pontos Quânticos/química
4.
Nanotechnology ; 30(36): 365702, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31026856

RESUMO

Although ceramic Al4O4C has recently been found to have interesting optical properties, its low conductivity makes it difficult to be used in fields related to electron transport. Here, we achieved carbon-in-Al4O4C core-shell nanoneedles via a one-step chemical vapor deposition method. The core with the form of few-layer graphene embedded in amorphous carbon improves the electron transport largely, as the I-V measurement is based on a single nanowire. Good field electron emission behavior was observed in these nanoneedles. Noticeably, when a large electric field was loaded, the nanoneedle failed in two manners, i.e. zippered dispassion between the core and shell, and chemical deposition of the Al4O4C shell into metastable δ-Al2O3. These results help to broaden the application field of Al4O4C and understand its physicochemical behavior under extreme conditions.

5.
Sensors (Basel) ; 19(3)2019 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-30691035

RESUMO

Structural health monitoring technologies have provided extensive methods to sense the stress of steel structures. However, monitored stress is a relative value rather than an absolute value in the structure's current state. Among all the stress measurement methods, ultrasonic methods have shown great promise. The shear-wave amplitude spectrum and phase spectrum contain stress information along the propagation path. In this study, the influence of uniaxial stress on the amplitude and phase spectra of a shear wave propagating in steel members was investigated. Furthermore, the shear-wave amplitude spectrum and phase spectrum were compared in terms of characteristic frequency (CF) collection, parametric calibration, and absolute stress measurement principles. Specifically, the theoretical expressions of the shear-wave amplitude and phase spectra were derived. Three steel members were used to investigate the effect of the uniaxial stress on the shear-wave amplitude and phase spectra. CFs were extracted and used to calibrate the parameters in the stress measurement formula. A linear relationship was established between the inverse of the CF and its corresponding stress value. The test results show that both the shear-wave amplitude and phase spectra can be used to evaluate uniaxial stress in structural steel members.

6.
J Bioenerg Biomembr ; 49(6): 437-443, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29164469

RESUMO

The anti-cancer activities of antibiotic anisomycin have been demonstrated in kidney, colon and ovarian cancers whereas its underlying mechanisms are not well elucidated. In this work, we investigated whether anisomycin is effective in sensitizes osteosarcoma cell response to chemotherapy. We show that anisomycin inhibits proliferation via inducing osteosarcoma cell arrest at G2/M phase, accompanied by the increased levels of mitotic marker cyclin B and the decreased levels of Rb and E2F-1. Anisomycin also induces apoptosis in a caspase-dependent manner in osteosarcoma cells. Importantly, anisomycin is less effective in normal control NIH3T3 cells compared to osteosarcoma cells. In addition, anisomycin inhibits osteosarcoma growth in xenograft mouse model and enhances the inhibitory effects of doxorubicin in osteosarcoma in vitro and in vivo. Mechanistically, anisomycin targets mitochondrial biogenesis in osteosarcoma as shown by the decreased mitochondrial membrane potential, suppressed mitochondrial respiration via decreasing complex I activity, reduced ATP production. Furthermore, mitochondrial biogenesis stimulator acetyl-L-Carnitine (ALCAR) significantly rescues the inhibitory effects of anisomycin in osteosarcoma cells. Our work demonstrates that anisomycin is active against osteosarcoma cells and the molecular mechanism of its action is the inhibition of mitochondrial biogenesis.


Assuntos
Anisomicina/farmacologia , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Biogênese de Organelas , Osteossarcoma/tratamento farmacológico , Animais , Linhagem Celular Tumoral , Xenoenxertos , Camundongos , Células NIH 3T3 , Osteossarcoma/patologia , Osteossarcoma/fisiopatologia
7.
ACS Sens ; 9(6): 3338-3345, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38814087

RESUMO

α-Dicarbonyl compounds (α-DCs) are important intermediate products during the thermal processing of foods and are closely related to the development of chronic diseases in the human body. However, there remains a significant gap in the availability of rapid detection methods for α-DCs. So, the ratiometric molecularly imprinted polymers (RCDs@GCOFs@MIPs) based on red-emitting biomass carbon dots (RCDs) and green-emitting fluorescent covalent organic frameworks (GCOFs) were constructed for the detection and removal of α-DCs in food processing. The ratiometric fluorescent sensors exhibited satisfactory detection and had good spiking recoveries in milk samples. And the excellent inhibition of pyrraline (PRL) by ratiometric fluorescent sensors was verified by simulating the milk pasteurization process. In addition, rapid onsite detection of α-DCs was achieved by recognizing the RGB value of the ratiometric fluorescence sensors via the smartphone. The ratiometric fluorescence sensors presented a new strategy for detecting and removing hazardous substances in food processing.


Assuntos
Carbono , Corantes Fluorescentes , Carbono/química , Corantes Fluorescentes/química , Leite/química , Impressão Molecular/métodos , Pontos Quânticos/química , Biomassa , Estruturas Metalorgânicas/química , Animais , Espectrometria de Fluorescência/métodos , Polímeros Molecularmente Impressos/química , Contaminação de Alimentos/análise , Limite de Detecção
8.
Food Chem ; 446: 138839, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38428083

RESUMO

α-Dicarbonyl compounds (α-DCs) are important intermediates and precursors of harmful Maillard reaction products (e.g., acrylamide and late glycosylation end-products), and they exist widely in thermoprocessed sugar- or fat-rich foods. α-DCs and their end-products are prone to accumulation in the human body and lead to the development of various chronic diseases. Therefore, detection of α-DCs and their associated hazards in food samples is crucial. This paper reviews the preparation of molecularly imprinted polymers (MIPs) enabling visual intelligent responses and the strategies for recognition and capture of α-DCs and their associated hazards, and provides a comprehensive summary of the development of visual MIPs, including integration strategies and applications with real food samples. The visual signal responses as well as the mechanisms for hazard recognition and capture are highlighted. Current challenges and prospects for visual MIPs with advanced applications in food, agricultural and environmental samples are also discussed. This review will open new horizons regarding visual MIPs for recognition and inhibition of hazards in food safety.


Assuntos
Impressão Molecular , Polímeros Molecularmente Impressos , Humanos , Polímeros , Inocuidade dos Alimentos , Produtos Finais de Glicação Avançada
9.
Food Chem ; 415: 135715, 2023 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-36842375

RESUMO

Herein, we reported the room-temperature fabrication of ionic liquid-modified carbon dots encapsulated in bionic antibodies (IL-modified CDs@BAs) by one-pot green synthesis. In order to enhance the fluorescence intensity of CDs, imidazole ILs and lemon rich in heteroatoms were selected as CDs modifiers and sources. The resulting IL-modified CDs@BAs showed good selectivity and capture toward urea and obviously induced fluorescence quenching by template-binding. The inhibition rate ofIL-modified CDs@BAs on the urea pathway of ethyl carbamate was about 29.07% in the simulated Huangjiu system, indicating a good inhibitory effect. The IL-modified CDs@BAs system was also reproducible after five consecutive uses, thus reducing the economic cost. This research would expand the application fields of BAs-based optical sensing system from the perspectives of energy conservation, environmental protection and resource recovery, focusing on their application in the field of food safety control.


Assuntos
Líquidos Iônicos , Pontos Quânticos , Carbono , Biomassa , Biônica , Microesferas , Anticorpos , Corantes Fluorescentes
10.
J Agric Food Chem ; 71(12): 4970-4981, 2023 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-36897289

RESUMO

Food-borne advanced glycation end products (AGEs) are highly related to various irreversible diseases, and Nε-(carboxymethyl)lysine (CML) is the typical hazardous AGE. The development of feasible strategies to monitor and reduce CML exposure has become desirable to address the problems. In this work, we proposed magnetically controlled nanorobots by integrating an optosensing platform with specific recognition and binding capability, realizing specific anchoring and accurate determination as well as efficient scavenging of CML in dairy products. The artificial antibodies offered CML imprinted cavities for highly selective absorption, and the optosensing strategy was designed based on electron transfer from red emissive self-assembling peptide dots (r-SAPDs) to CML, which was responsible for the identity, response, and loading process. The r-SAPDs overcame the interference from autofluorescence, and the limit of detection was 0.29 µg L-1, which bestowed accuracy and reliability for in situ monitoring. The selective binding process was accomplished within 20 min with an adsorption capacity of 23.2 mg g-1. Through an external magnetic field, CML-loaded nanorobots were oriented, moved, and separated from the matrix, which enabled their scavenging effects and reusability. The fast stimuli-responsive performance and recyclability of the nanorobots provided a versatility strategy for effective detection and control of hazards in food.


Assuntos
Anticorpos , Lisina , Reprodutibilidade dos Testes , Lisina/metabolismo , Produtos Finais de Glicação Avançada , Peptídeos , Laticínios
11.
Fundam Res ; 3(1): 118-125, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38933571

RESUMO

With low density, high porosity, and outstanding physicochemical stability, ceramic nanowire aerogels and sponges exhibit various interesting properties. Herein, an ultrathin silica nanowire aerogel (SiO2 NWs-A) was achieved via a facile chemical vapor deposition route. In addition to good mechanical and thermal performances, properties resulting from active water-aerogel interactions are revealed, i.e., outstanding transparency, strong capillary effect, enhanced compressive strength (a reversible strain of ∼62%), switchable wettability and robust shape retention ability when filled with water. The physical mechanism related to these interesting properties is demonstrated basically according to its unique features (distinctly reduced nanowire diameter, enriched nanoscopic gap channels, and reinforced network). To demonstrate the superiority, an advantageous solar vapor generation system (hydrophilic NWs-A/reduced graphene oxide (rGO)/ hydrophobic NWs-A) was obtained by integrating these favorable characteristics, giving rise to remarkably promoted vapor evaporation rate and energy efficiency compared to the rGO hydrophobic NWs-A device. These results contribute to the structural design and functional exploration of nanowire aerogels.

12.
Int J Biol Macromol ; 222(Pt A): 1229-1237, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36170931

RESUMO

Chitosan-based nanoparticles (CNPs) are widely used in drug delivery, cosmetics formulation and food applications. To accelerate the manufacturing of CNPs, the present study develops a workflow to prepare CNPs in a continuous model. Based on machine learning, the workflow precisely predicts size and polymer dispersity index (PDI) value of CNPs, which impacts on the colloidal stability and applications. Multi-inlet vortex mixer (MIVM) device was fabricated by 3D printing as the reactor. Peristaltic pump was applied to deliver the reaction streams into the MIVM device and produce CNPs by flash nanoprecipitation (FNP) in a continuous way. The developed MIVM device produces CNPs in a controlled manner at a higher output which is promising for upscale applications. Twelve machine learning algorithms were employed to investigate the potential relationship between the reaction independent variables and hydrodynamic characteristics of CNPs. Random Forest, Decision Tree, Extra Tree and Bagging algorithms performed better than other algorithms with the average prediction accuracy around 90 %. The current study demonstrated that supervised machine learning guided FNP using the developed MIVM device is an effective strategy for accurate and intelligent production of CNPs and other similar nanoparticles.


Assuntos
Quitosana , Nanopartículas , Sistemas de Liberação de Medicamentos , Polímeros , Aprendizado de Máquina
13.
Vaccines (Basel) ; 10(10)2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36298602

RESUMO

(1) Background: research on vaccines has received extensive attention during epidemics. However, few studies have focused on the impact of media use on vaccination behavior and the factors influencing vaccination in groups with different media use degrees; (2) Method: Based on seven items related to media use, a total of 11,031 respondents were categorized by the frequency of media use by using latent profile analysis (LPA). Binary regression analysis was used to study the factors that influence the vaccination behaviors of people with different media use frequencies; (3) Results: All respondents were classified into the following three groups: media use low frequency (9.7%), media use general (67.1%), and media use high frequency (23.2%). Media use low frequency (ß = −0.608, p < 0.001) was negatively associated with COVID-19 vaccination behavior. In the media use low frequency, analysis showed that "aged 41 years or older" ß = 1.784, p < 0.001), had religious belief (ß = 0.075, p < 0.05), were ethnic minorities (ß = 0.936, p < 0.01) and had friends support (ß = 0.923, p < 0.05) were associated with a preference to accept the COVID-19 vaccine. In the media use general, those who aged 41 years old and older (ß = 1.682, p < 0.001), had major depression (ß = 0.951, p < 0.05), had friends support (ß = 0.048, p < 0.001) would be more likely to receive COVID-19 vaccination. However, respondents who live in towns (ß = −0.300, p < 0.01) had lower behaviors to receive vaccination for COVID-19. In the media use high frequency, the respondents who aged 41 or older (ß = 1.010, p < 0.001), were ethnic minorities (ß = 0.741, p < 0.001), had moderate depression (ß = 1.003, p < 0.05) would receive the vaccination for COVID-19 positively; (4) Conclusions: The more occluded the media use is, the less likely the respondents are to get vaccinated against COVID-19. Vaccination behavior is influenced by different factors in groups with different frequencies of media use. Therefore, the government and appropriate departments should make individualized and targeted strategies about COVID-19 vaccination and disseminate the vaccination information to different media use groups.

14.
Mol Phylogenet Evol ; 57(3): 1091-104, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20955804

RESUMO

An aridification of the Tarim Basin and adjacent areas since middle Pleistocene has produced significant genetic structuring of the local fauna. We examined the phylogeographic patterns, population structure and history of Phrynocephalus axillaris and Phrynocephalus forsythii using a mitochondrial fragment ND4-tRNA(LEU). Phylogenetic hypotheses were constructed using maximum parsimony and Bayesian inference, and the divergence times of major lineages were estimated by BEAST. Population structure and history were inferred by nested clade analysis, neutrality tests, mismatch distribution, and isolation by distance analysis. The two species might have experienced different evolutionary history throughout their current distribution. For P. forsythii, a vicariant event, as a consequence of geological isolation and desert expansion, might have produced the significant divergence between the Tarim and the Yanqi populations. For P. axillaris, populations of the Yanqi, Turpan and Hami Basins might have been established through dispersal during demographic expansion. Climatic fluctuations caused alternate expansion and shrinkage of rivers and oases several times, which likely led to habitat fragmentation for both species. Interaction between vicariance, dispersal and habitat fragmentation produced the current distribution and genetic diversity. The observed difference between the two species may be due partially to their different reproductive modes (ovoviviparous vs. oviparous).


Assuntos
Evolução Molecular , Lagartos/genética , Filogeografia , Animais , China , DNA Mitocondrial/genética , Ecossistema , Feminino , Genética Populacional , Lagartos/classificação , Oviparidade , Ovoviviparidade , Filogenia , Análise de Sequência de DNA
15.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 27(3): 272-5, 2010 Jun.
Artigo em Zh | MEDLINE | ID: mdl-20533264

RESUMO

OBJECTIVE: To investigate the splice variants of the calpain 3 gene existing in human skeletal muscle tissue and white blood cells, and to explore the feasibility of gene diagnosis using CAPN3 mRNA extracted from peripheral leukocytes. METHODS: Total RNA was extracted from peripheral blood and skeletal muscle tissue in healthy individuals. CAPN3 cDNAs were determined by reverse transcriptase polymerase chain reaction and DNA sequencing. CAPN3 cDNAs from peripheral leukocytes were compared with sequences obtained from skeletal muscle tissue. RESULTS: RT-PCR and DNA sequencing showed that the CAPN3 cDNAs comprised 24 exons in human skeletal muscle tissue, while the number of exons was 23 in white blood cells. Exon 15 was spliced out in human white blood cells. CONCLUSION: Splice variants exist in human skeletal muscle tissue and white blood cells. Gene diagnosis may omit the mutations of exon 15 using mRNA extracted from peripheral leukocytes. These findings suggest that mutation analysis of the CAPN3 cDNA should use skeletal muscle tissue as materials instead of peripheral blood.


Assuntos
Calpaína/genética , Leucócitos/metabolismo , Proteínas Musculares/genética , Músculo Esquelético/metabolismo , Análise Mutacional de DNA , DNA Complementar/genética , Éxons/genética , Humanos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
16.
Food Chem ; 307: 125534, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31644980

RESUMO

There has been increasing recent concern about the agricultural use of organophosphorus pesticides. A rapid and sensitive fluorescence assay for the detection of three organophosphorus pesticides has therefore been developed using 6-carboxy-fluorescein labeling aptamer as the probe and functionalized magnetic nanoparticles as the separation carrier. The aptamer hybridized with complementary DNA conjugated on the surface of the magnetic nanoparticles to form a magnetic aptamer-complementary DNA complex. Upon introducing the target organophosphorus pesticide, the aptamer departed from the complementary DNA, resulting in the fluorescence signal. Under optimized conditions, the limits of detection (LODs, S/N = 3) for trichlorfon, glyphosate, and malathion were 72.20 ng L-1, 88.80 ng L-1, and 195.37 ng L-1, respectively. The method was applied for the detection of trichlorfon, glyphosate, and malathion in spiked lettuce and carrot samples. The recoveries were in the range of 79.4%-118.7%, which were in good agreement with those obtained by gas chromatography, and the relative standard deviations were also acceptable. The method therefore has high sensitivity, so provides a means for the detection of multiple organophosphorus pesticides.


Assuntos
Aptâmeros de Nucleotídeos/química , Nanopartículas , Compostos Organofosforados/análise , Praguicidas/análise , Espectrometria de Fluorescência , Cromatografia Gasosa , Daucus carota/química , Corantes Fluorescentes , Glicina/análogos & derivados , Glicina/análise , Lactuca/química , Limite de Detecção , Magnetismo , Malation/análise , Praguicidas/química , Triclorfon/análise , Glifosato
17.
Nat Commun ; 11(1): 647, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32005830

RESUMO

Providing high performance electrical nano-interconnects for micro-nano electronics that are robust in harsh environments is highly demanded. Today, electrical nano-interconnects based on metallic nanowires, e.g. Ag and Cu, are limited by their positive physicochemical reactivity and ductility under large strain (i.e. irreversible dislocations and local necking-down elongation) at high temperatures or in strong oxidizing and acidic environments. Herein, to overcome these limitations, high-quality millimetre-sized soft manganese-based silicide (Mn5Si3@SiO2) nanowire nanocables are designed via a glassy Si-Mn-O matrix assisted growth. The proposed nanocables exhibit good electrical performance (resistivity of 1.28 to 3.84×10-6 Ωm and maximum current density 1.22 to 3.54×107 A cm-2) at temperatures higher than 317°C in air atmosphere, strongly acidic (HCl, PH=1.0) and oxidizing (H2O2, 10%) ambient, and under complex electric field. The proposed Mn5Si3@SiO2 nanocables, which withstand a strain of 16.7% free of failure, could be exploited for diverse applications in flexible electronics and complex wiring configurations.

18.
Talanta ; 199: 581-589, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30952301

RESUMO

Heteroatom doping can endow graphene quantum dots (GQDs) with various new or improved structural, optical and physicochemical properties. In contrast to the widely reported oxygen, nitrogen or sulfur doping in GQDs, simple and scalable synthesis of boron-doped GQDs (B-GQDs) with high yield and quantum yields remains challenge. In this work, B-GQDs are one-step synthesized and serve as the fluorescence probes for the fabrication of sensors towards Fe3+ ion or phosphate (Pi) as well as biosensor towards cytochrome C (Cyt C). The B-GQDs are facile synthesized using one-step bottom-up molecular fusion between 1,3,6-trinitropyrene and borax in sodium hydroxide under hydrothermal process. The synthesis can be performed using large volume autoclave (500 ml) with a high yield of 71%, indicating possibility for gram-scale production of B-GQDs. The as-prepared B-GQDs exhibit single or bilayer graphene structure, high crystallinity, uniform size, bright (absolute photoluminescence quantum yield of 16.8%) and excitation-independent green fluorescence (maximum excitation wavelength and emission wavelength of 480 nm and 520 nm, respectively). Successful doping of B atoms in the lattice of GQDs enables high selectivity towards Fe3+. Based on quenching of fluorescence of B-GQDs by Fe3+ (turn-off model), detection of Fe3+ (with limit of detection-LOD of 31.2 nM) and Fe3+-rich Cyt C (with LOD of 5.9 µg/ml) are demonstrated. As Pi can recover Fe3+-quenched fluorescence of B-GQDs (turn-off-on model), indirect fluorescent detection of Pi is also achieved with LOD of 340 nM. In addition, detection of Fe3+, Cyt C and Pi in real samples is achieved.


Assuntos
Técnicas Biossensoriais , Boro/química , Citocromos c/análise , Compostos Férricos/análise , Fluorescência , Grafite/química , Fosfatos/análise , Pontos Quânticos/química , Tamanho da Partícula , Espectrometria de Fluorescência , Propriedades de Superfície
19.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 25(5): 550-4, 2008 Oct.
Artigo em Zh | MEDLINE | ID: mdl-18841570

RESUMO

OBJECTIVE: To analyze the chromosome aberration in a full-term male neonate with low birth weight, and to explore the possible causes for growth retardation in intrauterine development for the neonate. METHODS: Genomic DNA was extracted from peripheral leukocytes of the neonate. Detection of genomic DNA copy number gain and loss was performed using microarray comparative genomic hybridization. Chromosome karyotype was obtained from cultured lymphocytes for the neonate and his parents in order to identify the origin of chromosome aberration. RESULTS: Gain of 10q25.2-->qter (22 Mb) was observed in the full-term neonate with low birth weight. In addition, one chromosomal region, 15q26.2-->qter (5 Mb) was lost. The karyotype of the neonate was 46, XY, -15, +der(15), t(10;15)(q25;q26)pat. CONCLUSION: The full-term neonate with low birth weight had a partial trisomy of 10q25.2-->qter with a partial monosomy of 15q26.2-->qter, both of them may contribute to the growth retardation in intrauterine development for the neonate case.


Assuntos
Aberrações Cromossômicas , Recém-Nascido de Baixo Peso , Nascimento a Termo/genética , Deleção Cromossômica , Cromossomos Humanos Par 15/genética , Hibridização Genômica Comparativa , Feminino , Dosagem de Genes , Genoma Humano/genética , Humanos , Lactente , Recém-Nascido , Cariotipagem , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Gravidez , Controle de Qualidade , Trissomia
20.
Zhongguo Dang Dai Er Ke Za Zhi ; 10(1): 35-7, 2008 Feb.
Artigo em Zh | MEDLINE | ID: mdl-18289468

RESUMO

OBJECTIVE: Duchenne muscular dystrophy (DMD) usually occurs prior to 3 years old. The value of serum creatine kinase changes with clinical progression and age in patients with DMD. This study aimed to investigate the regularity in the changes of serum creatine kinase activities in children with DMD. METHODS: Peripheral blood samples were obtained from 40 children with DMD (ranged from 3-14 years). Serum creatine kinase levels were assayed by kinetic UV test. RESULTS: Serum creatine kinase level in the 40 DMD patients (ranged from 2 595- 45 495 U/L) was remarkably higher than the reference value (35-174 U/L). The highest serum creatine kinase level (average: 27750-31173 U/L) was found in 3-5 years old patients. Afterwards, serum creatine kinase level decreased with clinical progression and age, with a yearly average rate of decline was 8.7%. CONCLUSIONS: Serum creatine kinase level reaches a peak between 3 and 5 years old and then reduces with increasing age in children with DMD. The characteristic changes of serum creatine kinase are suspected to reflect the rate of muscle decay.


Assuntos
Creatina Quinase/sangue , Distrofia Muscular de Duchenne/sangue , Adolescente , Corticosteroides/uso terapêutico , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Distrofia Muscular de Duchenne/tratamento farmacológico , Distrofia Muscular de Duchenne/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA