Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 110
Filtrar
1.
J Clin Nurs ; 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38629347

RESUMO

AIMS AND OBJECTIVES: This study aims to analyse the trends in the incidence, prevalence and medical costs of pressure injuries (PIs) among genders in Taiwan. BACKGROUND: The treatment of PIs is complex and costly, often leading to complications and increased mortality. This issue significantly impacts healthcare quality and incurs substantial medical and social costs, warranting attention. METHODS: A retrospective cohort study was conducted using data from Taiwan's National Health Insurance Database to obtain and calculate the incidence, prevalence, and medical costs of PIs in the country between 2001 and 2015 as well as to analyse high-risk groups and the medical care utilisation of patients following the STROBE reporting guidelines. RESULTS: Between 2001 and 2015, 15,327 incident case of PIs were diagnosed. During the study period, the prevalence rate of PIs per 100,000 population rose from 26.3 to 189.6, with approximately 11.5%-16.3% of patients undergoing surgical debridement. The PIs prevalence rate increased by 7.2-fold, and hospitalisation costs accounted for 91.7%-96.0% of the total medical costs. Patients with older age, comorbidities, poorer financial status and lower education levels were found to be likely to develop PIs. These predisposing factors differed between males and females. The prevalence of PIs was higher in patients ≥75 years old than in patients from other age groups. Moreover, PI-related medical expenses have been increasing annually. CONCLUSIONS: In Taiwan, the rising incidence of PIs is driving up medical costs. Effective care and prevention of PIs necessitate a comprehensive plan from the entire healthcare system. RELEVANCE TO CLINICAL PRACTICE: This research fills a gap in the available data on the incidence, prevalence, and medical costs of PIs in Taiwan and Asia. PATIENT OR PUBLIC CONTRIBUTION: The findings can be used to help develop clinical guidelines for preventive education and treatment of PIs.

2.
J Sep Sci ; 46(23): e2300557, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37803927

RESUMO

This study developed a facile, highly sensitive technique for extracting and quantifying barbiturates in serum samples. This method combined ultrasound and surfactant-assisted dispersive liquid-liquid microextraction with poly(ethylene oxide)-mediated stacking in capillary electrophoresis. Factors influencing the extraction and stacking performance, such as the type and volume of extraction solvents, the type and concentration of surfactant, extraction time, salt additives, sample matrix, solution pH, and composition of the background electrolyte, were carefully studied and optimized to achieve the optimal detection sensitivity. Under the optimized extraction (injecting 140 µL C2 H4 Cl2 into 1 mL of sample with pH 4 (5 mM sodium phosphate containing 0.05 mM Tween 20 and sonication for 1 min) and separation conditions (150 mM tris(hydroxymethyl)aminomethane-borate with pH 8.5 containing 0.5% (m/v) poly(ethylene oxide)), the limits of detection (signal-to-noise ratio = 3) of five barbiturates ranged from 0.20 to 0.33 ng/mL, and the calculated sensitivity improvement ranged from 868- to 1700-fold. The experimental results revealed excellent linearity (R2  > 0.99), with relative standard deviations of 2.1%-3.4% for the migration time and 4.3%-5.7% for the peak area. The recoveries of the spiked serum samples were 97.1% -110.3%. Our proposed approach offers a rapid and practical method for quantifying barbiturates in biological fluids.


Assuntos
Microextração em Fase Líquida , Tensoativos , Humanos , Polietilenoglicóis , Óxido de Etileno , Microextração em Fase Líquida/métodos , Solventes/química , Limite de Detecção
3.
BMC Med Imaging ; 23(1): 151, 2023 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-37814246

RESUMO

BACKGROUND: The safety and efficacy of 17-gauge needles used in CT-guided percutaneous cryoablation for lung nodules were explored in this study. The purpose of the study was to compare the findings with earlier research and multi-center clinical trials that used various needle sizes. METHODS: Between 2016 and 2020, a retrospective study was conducted with approval from the institutional review board. A total of 41 patients were enrolled, and 71 lung nodules were treated in 63 cryoablation procedures using local anesthesia. Complication rates were recorded, and overall survival rates as well as tumor progression-free rates were calculated using the Kaplan-Meier method. RESULTS: Self-limited hemoptysis was caused by 12.9% of the procedures, and drainage was required for pneumothoraces resulting from 11.3% of them. The overall survival rates at one, two, three, and four years were 97%, 94%, 82%, and 67%, respectively. The tumor progression-free rates at one, two, three, and four years were 86.2%, 77%, 74%, and 65%, respectively. CONCLUSION: Cryoablation for lung nodules using 17-Gauge needles can achieve similar rates of survival and tumor control rates, similar or even lower complication rates as compared with other studies and multi-center trials using mixed sized needles.


Assuntos
Criocirurgia , Neoplasias , Humanos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Pulmão/diagnóstico por imagem , Pulmão/cirurgia , Pulmão/patologia
4.
Mol Biol Evol ; 38(7): 2715-2731, 2021 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-33674876

RESUMO

SARS-CoV-2 infects humans through the binding of viral S-protein (spike protein) to human angiotensin I converting enzyme 2 (ACE2). The structure of the ACE2-S-protein complex has been deciphered and we focused on the 27 ACE2 residues that bind to S-protein. From human sequence databases, we identified nine ACE2 variants at ACE2-S-protein binding sites. We used both experimental assays and protein structure analysis to evaluate the effect of each variant on the binding affinity of ACE2 to S-protein. We found one variant causing complete binding disruption, two and three variants, respectively, strongly and mildly reducing the binding affinity, and two variants strongly enhancing the binding affinity. We then collected the ACE2 gene sequences from 57 nonhuman primates. Among the 6 apes and 20 Old World monkeys (OWMs) studied, we found no new variants. In contrast, all 11 New World monkeys (NWMs) studied share four variants each causing a strong reduction in binding affinity, the Philippine tarsier also possesses three such variants, and 18 of the 19 prosimian species studied share one variant causing a strong reduction in binding affinity. Moreover, one OWM and three prosimian variants increased binding affinity by >50%. Based on these findings, we proposed that the common ancestor of primates was strongly resistant to and that of NWMs was completely resistant to SARS-CoV-2 and so is the Philippine tarsier, whereas apes and OWMs, like most humans, are susceptible. This study increases our understanding of the differences in susceptibility to SARS-CoV-2 infection among primates.


Assuntos
COVID-19 , Resistência à Doença/genética , Peptidil Dipeptidase A , SARS-CoV-2 , Animais , COVID-19/genética , COVID-19/imunologia , Chlorocebus aethiops , Humanos , Macaca mulatta , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/imunologia , SARS-CoV-2/genética , SARS-CoV-2/imunologia
5.
Plant Dis ; 104(5): 1318-1327, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32181724

RESUMO

A new begomovirus, tentatively named hibiscus yellow vein leaf curl virus (HYVLCV), was identified in Hibiscus rosa-sinensis plants showing symptoms of leaf curl, yellow vein, and vein enation on the undersides of the leaf in Taiwan. Sequence analysis of the full-length HYVLCV genome from the rolling cycle amplicon revealed a genome of 2,740 nucleotides that contains six open reading frames and a conserved sequence (5'-TAATATTAC-3') commonly found in geminiviral genomes. HYVLCV shares the highest nucleotide identity (88.8%) with cotton leaf curl Multan virus (CLCuMuV) genome, which is lower than the criteria (91%) set for species demarcation in the genus Begomovirus. No begomoviral DNA-B was detected; however, a begomovirus-associated DNA betasatellite (DNA-ß) was detected. The DNA-ß (1,355 nucleotides) shares the highest nucleotide identity (78.6%) with malvastrum yellow vein betasatellite (MaYVB). Because the identity is slightly higher than the criteria (78%) set for the species demarcation threshold for a distinct DNA-ß species, the DNA-ß of HYVLCV reported in this study is considered the same species of MaYVB and tentatively named MaYVB-Hib. An expected 1,498-bp fragment was amplified with two HYVLCV-specific primers from 10 of 11 field-collected samples. Four independent amplicons were sequenced, revealing 100% nucleotide identity with the HYVLCV genome. Agroinoculation of a dimer of the infectious monopartite genome alone to Nicotiana benthamiana resulted in mild symptoms at 28 days postinoculation (dpi); coagroinoculation with the DNA-ß satellite resulted in severe symptoms at 12 dpi. HYVLCV could be transmitted to healthy H. rosa-sinensis by grafting, resulting in yellow vein symptoms at 30 dpi.


Assuntos
Begomovirus , Hibiscus , Rosa , Genoma Viral , Filogenia , Doenças das Plantas , Análise de Sequência de DNA , Taiwan
6.
Plant Dis ; 103(7): 1605-1612, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30998416

RESUMO

Dendrobium smillieae is one of the popular orchids in Taiwan. This report describes a new potyvirus tentatively named Dendrobium chlorotic mosaic virus (DeCMV) causing chlorotic and mosaic symptoms in D. smillieae. Enzyme-linked immunosorbent assay (ELISA) tests using six antisera against orchid-infecting viruses revealed that only a monoclonal antibody against the potyvirus group reacted positively with crude saps prepared from a symptomatic dendrobium orchid. Potyvirus-like, flexuous, filamentous particles were observed under an electron microscope, measuring approximately 700 to 800 nm in length and 11 to 12 nm in diameter. Sequence analyses revealed that DeCMV coat protein gene shared 59.6 to 66.0% nucleotide sequence identity and 57.6 to 66.0% amino acid sequence identity, whereas the DeCMV complete genome shared 54.1 to 57.3% nucleotide sequence identity and 43.7 to 49.5% amino acid sequence identity with those other known potyviruses. These similarity levels were much lower than the criteria set for species demarcation in potyviruses. Thus, DeCMV can be considered a new potyvirus. The whole DeCMV genome contains 10,041 nucleotides (GenBank accession no. MK241979) and encodes a polyprotein that is predicted to produce 10 proteins by proteolytic cleavage. In a pathogenicity test, results of inoculation assays demonstrated that DeCMV can be transmitted to dendrobium orchids by grafting and mechanical inoculation, as verified by ELISA and western blot analyses using the DeCMV polyclonal antiserum and by reverse transcription polymerase chain reaction using the coat protein gene-specific primers. The inoculated orchids developed similar chlorotic and mosaic symptoms. In conclusion, DeCMV is a novel orchid-infecting potyvirus, and this is the first report of a new potyvirus that infects dendrobium orchids in Taiwan.


Assuntos
Dendrobium , Potyvirus , Sequência de Aminoácidos , Dendrobium/virologia , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Filogenia , Potyvirus/classificação , Potyvirus/genética , Taiwan
7.
Molecules ; 24(9)2019 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-31072045

RESUMO

A novel sensing system has been designed for the detection of cupric ions. It is based on the quenched fluorescence signal of carbon dots (CDs), which were carbonized from poly(vinylpyrrolidone) (PVP) and L-Cysteine (CYS). Cupric ions interact with the nitrogen and sulfur atoms on surface of the CDs to form an absorbed complex; this results in strong quenching of the fluorescence of the CDs via a fast metal-to-ligand binding affinity. The synthesized water-soluble CDs also exhibited a quantum yield of 7.6%, with favorable photoluminescent properties and good photostability. The fluorescence intensity of the CDs was very stable in high ionic strength (up to 1.0 M NaCl) and over a wide range of pH levels (2.0-12.0). This facile method can therefore develop a sensor that offers reliable, fast, and selective detection of cupric ions with a detection limit down to 0.15 µM and a linear range from 0.5 to 7.0 µM (R2 = 0.980). The CDs were used for cell imaging, observed that they were low toxicity to Tramp C1 cells and exhibited blue and green and red fluorescence under a fluorescence microscope. In summary, the CDs exhibited excellent fluorescence properties, and could be applied to the selective and sensitive detection of cupric ion and multicolor cell imaging.


Assuntos
Carbono/química , Cobre/análise , Imageamento Tridimensional/métodos , Sondas Moleculares/síntese química , Pontos Quânticos/química , Animais , Carbono/toxicidade , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Fluorescência , Íons , Camundongos Transgênicos , Sondas Moleculares/química , Espectroscopia Fotoeletrônica , Pontos Quânticos/toxicidade , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/análise
8.
Arch Virol ; 162(7): 2109-2113, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28260140

RESUMO

Pepper chlorotic spot virus (PCSV), newly found in Taiwan, was identified as a new tospovirus based on the molecular characterization of its S RNA. In this study, the complete M and L RNA sequences of PCSV were determined. The M RNA has 4795 nucleotides (nts), encoding the NSm protein of 311 aa (34.5 kDa) in the viral (v) strand and the glycoprotein precursor (Gn/Gc) of 1122 aa (127.6 kDa) in the viral complementary (vc) strand. The L RNA has 8859 nts, encoding the RNA-dependent RNA polymerase (RdRp) of 2873 aa (330.8 kDa) in the vc strand. Analyses of the NSm, Gn/Gc and RdRp of PCSV revealed that PCSV is phylogenetically clustered within the watermelon silver mottle virus-related clade. Based on the whole genome sequence, PCSV is closely related to Tomato necrotic ringspot virus and should be classified as a new tospovirus species.


Assuntos
Piper nigrum/virologia , Doenças das Plantas/virologia , RNA Viral/genética , RNA Polimerase Dependente de RNA/genética , Tospovirus/classificação , Sequência de Aminoácidos , Solanum lycopersicum/virologia , Filogenia , Taiwan , Tospovirus/genética , Tospovirus/isolamento & purificação , Proteínas Virais/genética
9.
Anal Bioanal Chem ; 408(1): 77-82, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26514673

RESUMO

One-pot green synthesis of fluorescent nitrogen-doped carbon nanodots (CNDs) was developed by hydrothermal treatments of biocompatible polyvinylpyrrolidone (PVP) and glycine. The fluorescent nitrogen-doped CNDs exhibited excellent water solubility, low cytotoxicity, and good salt stability for biological imaging. UV-vis spectroscopy, fluorescence spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) spectroscopy, and Raman spectroscopy were applied to confirm the optical and structural characteristics of the CNDs. Fluorescence of the CNDs was tunable from 417 to 450 nm adjusted by different excitation energy. Fluorescent quantum yield of the CNDs (21.43%) was significantly increased ~47.59% in comparison to that of the CNDs (14.52%) without nitrogen doping by glycine. In the in vivo imaging system (IVIS), fluorescence signal of the nitrogen-doped CNDs was obviously observed in the lungs at 12- and 24-h post-injection. Our work has shown the potential applications of the nitrogen-doped CNDs in fluorescence imaging in vivo.


Assuntos
Imagem Molecular/métodos , Neoplasias/química , Pontos Quânticos/química , Animais , Carbono/química , Linhagem Celular Tumoral , Corantes Fluorescentes/química , Humanos , Pulmão/química , Camundongos , Imagem Molecular/instrumentação , Nitrogênio/química
10.
J Sep Sci ; 39(24): 4841-4850, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27758043

RESUMO

Dispersive liquid-liquid microextraction was combined with acetonitrile stacking in capillary electrophoresis for the identification of three selective serotonin reuptake inhibitors (citalopram, fluoxetine, and fluvoxamine) in human fluids such as urine and plasma. Parameters that affect the extraction and stacking efficiency, such as the type and volume of the extraction and disperser solvent, extraction time, salt addition for dispersive liquid-liquid microextraction, and sample matrices, pH, and concentration of the separation buffer for stacking, were investigated and optimized. Under optimum conditions, the enrichment factors were in the range of 1195-1441. Limits of detection ranged from 1.4 to 1.7 nM for the target analytes. Calibration graphs displayed satisfied linearity with R2 greater than or equal to 0.9978, and relative standard deviations of the peak area analysis were in the range of 2.9-5.0% (n = 3). The recoveries of all tricyclic antidepressant drugs from urine and plasma were in the range of 77-117 and 79-106%, respectively. The findings of this study show that dispersive liquid-liquid microextraction acetonitrile-stacking capillary electrophoresis is a rapid and convenient method for identifying tricyclic antidepressant drugs in urine and plasma.


Assuntos
Eletroforese Capilar , Microextração em Fase Líquida , Inibidores Seletivos de Recaptação de Serotonina/sangue , Inibidores Seletivos de Recaptação de Serotonina/urina , Acetonitrilas , Humanos
11.
Hu Li Za Zhi ; 63(5): 86-94, 2016 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-27699743

RESUMO

BACKGROUND: Noninvasive positive pressure ventilation (NPPV) provides ventilation without tracheal intubation. Facial pressure injury is a recognized complication of this technique, making the prevention of facial pressure injuries an important issue for NPPV patients. PURPOSE: The present study compared the effects of foam dressing and hydrocolloid dressing in preventing facial pressure injuries in NPPV patients. METHODS: A randomized clinical trial was used to evaluate participants that were referred from the intensive care unit of a medical center in eastern Taiwan. Participants were randomized into two groups: the foam dressing group and the hydrocolloid dressing group. Statistics used in analysis were: analysis mean, standard deviation, chi-square, independent t-test, and the generalized estimating equation. RESULTS: Sixty participants were enrolled as participants. The incidence rate of facial pressure injury was 11.7% (7/60). No significant difference was found between the two groups in terms of duration of NPPV use, incidence of facial pressure injury, and occurrence time of facial pressure injury. However, the hydrocolloid dressing group had a higher usage amount than the foam dressing group (p < .05). CONCLUSIONS: Foam and hydrocolloid dressings are both helpful in preventing facial pressure injury when used in conjunction with regular skin assessments.


Assuntos
Bandagens , Traumatismos Faciais , Ventilação não Invasiva , Respiração com Pressão Positiva , Úlcera por Pressão , Ventiladores Mecânicos , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Curativos Hidrocoloides , Traumatismos Faciais/prevenção & controle , Ventilação não Invasiva/instrumentação , Respiração com Pressão Positiva/instrumentação , Úlcera por Pressão/prevenção & controle
12.
Anal Bioanal Chem ; 406(2): 635-41, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24247553

RESUMO

A simple, low-cost, and efficient online focusing method that combines a dynamic pH junction and sweeping by capillary electrophoresis with polymer solutions was developed and optimized for the simultaneous determination of benzoic acid (BA) and sorbic acid (SA). A sample solution consisting of 2.5 mM phosphate at pH 3.0 and a buffer solution containing 15 mM tetraborate (pH 9.2), 40 mM sodium dodecyl sulfate, and 0.100 % (w/v) poly(ethylene oxide) were utilized to realize dynamic pH junction-sweeping for BA and SA. Under the optimized conditions, the entire analysis process was completed in 7 min, and a 900-fold sensitivity enhancement was achieved with limits of detection (S/N = 3) as low as 8.2 and 6.1 nM for BA and SA, respectively. The linear ranges were between 20 nM and 20 µM for BA and 20 nM and 10 µM for SA, with correlation coefficients greater than 0.992. The recoveries of the proposed method ranged from 90 to 113 %. These satisfactory results indicate that this method has the potential to be an effective analytical tool for the rapid screening of BA and SA in different food products.


Assuntos
Ácido Benzoico/análise , Conservantes de Alimentos/análise , Ácido Sórbico/análise , Bebidas Gaseificadas/análise , Eletroforese Capilar , Humanos , Concentração de Íons de Hidrogênio , Alimentos de Soja/análise , Vinho/análise
13.
Int J Mol Sci ; 15(5): 7266-80, 2014 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-24786089

RESUMO

Identifying trace amounts of bacteria rapidly, accurately, selectively, and with high sensitivity is important to ensuring the safety of food and diagnosing infectious bacterial diseases. Microbial diseases constitute the major cause of death in many developing and developed countries of the world. The early detection of pathogenic bacteria is crucial in preventing, treating, and containing the spread of infections, and there is an urgent requirement for sensitive, specific, and accurate diagnostic tests. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is an extremely selective and sensitive analytical tool that can be used to characterize different species of pathogenic bacteria. Various functionalized or unmodified nanomaterials can be used as affinity probes to capture and concentrate microorganisms. Recent developments in bacterial detection using nanomaterials-assisted MALDI-MS approaches are highlighted in this article. A comprehensive table listing MALDI-MS approaches for identifying pathogenic bacteria, categorized by the nanomaterials used, is provided.


Assuntos
Bactérias/isolamento & purificação , Infecções Bacterianas/microbiologia , Nanoestruturas/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Infecções Bacterianas/diagnóstico , Humanos
14.
ACS Omega ; 9(23): 24970-24977, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38882141

RESUMO

In this study, tannic acid (TA) was applied as a stabilizing agent for synthesizing bimetallic copper-gold (CuAu) nanoparticles. Cu(NO3)2 and NaAuCl4 were used as the sources of copper and gold ions, respectively, and NaBH4 was employed as a reducing agent. The prepared TA-CuAu nanoparticles were extensively characterized via ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction, and zeta potential analyses. To evaluate their catalytic activity, the TA-CuAu nanoparticles and NaBH4 were applied in the degradation of 4-nitrophenol (4-NP) and rhodamine B (RB) individually and in a mixture. The individual degradation of 4-NP and RB was completed within 10 min, and the apparent rate constants were calculated as 0.3046 and 0.2628 min-1, respectively, emphasizing the efficient catalytic activity of the TA-CuAu nanoparticles. Additionally, controlled experiments were performed for the degradation of 4-NP and RB in the absence of catalysts or NaBH4 to investigate the kinetic feasibility of the catalytic reactions. A mixture of 4-NP and RB was successfully degraded within 10 min using the TA-CuAu nanoparticles as catalysts. Furthermore, the reuse of the catalysts after five successive cycles demonstrates an outstanding performance with no significant loss in the catalytic activity. Finally, the successful treatment of the tap and lake water samples spiked with 4-NP and RB using the TA-CuAu nanoparticles further confirmed their application potential as catalysts in environmental water remediation.

15.
ACS Omega ; 9(9): 10621-10627, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38463298

RESUMO

Excessive administration of penicillin G and improper disposal of its residues pose a serious risk to human health; therefore, the development of convenient methods for monitoring penicillin G levels in products is essential. Herein, novel gold-silver nanoclusters (AuAgNCs) were synthesized using chicken egg white and 6-aza-2-thiothymine as dual ligands with strong yellow fluorescence at 509 and 689 nm for the highly selective detection of penicillin G. The AuAgNCs were characterized using transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet-visible absorption spectrophotometry, and fluorescence spectrophotometry. Under optimum conditions, the fluorescence intensity decreased linearly with the concentration of penicillin G from 0.2 to 6 µM, with a low detection limit of 18 nM. Real sample analyses indicated that a sensor developed using the AuAgNCs could detect penicillin G in urine and water samples within 10 min, with the recoveries ranging from 99.7 to 104.0%. The particle size of the AuAgNCs increased from 1.80 to 9.06 nm in the presence of penicillin G. We believe the aggregation-induced quenching of the fluorescence of the AuAgNCs was the main mechanism for the detection of penicillin G. These results demonstrate the ability of our sensor for monitoring penicillin G levels in environmental and clinic samples.

16.
Anal Bioanal Chem ; 405(25): 7919-30, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23539097

RESUMO

This article highlights recent methodological developments in the on-line concentration and separation of amino acids and their enantiomers using capillary electrophoresis. Sections are dedicated to recent contributions to on-line concentration strategies such as field-amplified sample stacking, large-volume sample stacking, dynamic pH junction, transient isotachophoresis, sweeping, and the combination of two methods. The main applications, advantages, and limitations of these procedures in the biological, food, and pharmaceutical fields are addressed. Comprehensive tables listing on-line techniques for the concentration and separation of amino acids and their enantiomers, categorized by the stacking strategies used, background electrolytes, sample matrix, limit of detection, and enhancement factor, are provided.


Assuntos
Aminoácidos/isolamento & purificação , Eletroforese Capilar/métodos , Animais , Eletroforese Capilar/instrumentação , Humanos , Concentração de Íons de Hidrogênio , Isotacoforese/instrumentação , Isotacoforese/métodos , Estereoisomerismo
17.
Int J Cosmet Sci ; 35(4): 346-53, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23336402

RESUMO

A micellar electrokinetic chromatography method using cetyltrimethylammonium bromide (CTAB) as a cationic surfactant, coupled with UV-Vis detection, was developed for the simultaneous determination of seven preservatives, including methyl-, ethyl-, propyl- and butyl-paraben and phenol, phenoxyethanol and resorcinol. The method involved optimizing the pH of the phosphate buffer and concentrations of CTAB, ethanol and 2-hydroxypropyl-ß-cyclodextrin (HP-ß-CD). The preservatives were well separated using optimum conditions and separated within 10 min at a separation voltage of -12.5 kV with the 1.0 mM phosphate buffer (pH 7.0) containing 90 mM CTAB, 25 mM HP-ß-CD and 10% (v/v) ethanol. Satisfactory recoveries (84.1-103.0%), migration time (RSD < 3.1%) and peak area (RSD < 4.5%) repeatabilities were achieved. Detection limits of the preservatives were between 0.31 and 1.52 µg mL(-1) (S/N = 3, n = 5). The optimized method was successfully applied to the simultaneous determination of these preservatives in 10 commercial cosmetic products.


Assuntos
Cromatografia Capilar Eletrocinética Micelar/métodos , Cosméticos , Conservantes Farmacêuticos/análise , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Reprodutibilidade dos Testes , Espectrofotometria Ultravioleta
18.
Micromachines (Basel) ; 14(9)2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37763872

RESUMO

In this paper, the performance of Cu-(In,Ga)-S2 (CIGS2) solar cells with adjusting composite [Cu]/([Ga] + [In]) (CGI)-ratio absorber was explored and compared through an improved three-stage co-evaporation technique. For co-evaporating CIGS2 absorber as a less toxic alternative to Cd-containing film, we analyzed the effect of the CGI-ratio stoichiometry and crystallinity, and explored its opto-electric sensing characteristic of individual solar cell. The results of this research signified the potential of high-performance CIGS2-absorption solar cells for photovoltaic (PV)-module industrial applications. For the optimal CIGS2-absorption film (CGI = 0.95), the Raman main-phase signal (A1) falls at 291 cm-1, which was excited by the 532 nm line of Ar+-laser. Using photo-luminescence (PL) spectroscopy, the corresponding main-peak bandgaps measured was 1.59 eV at the same CGI-ratio film. Meanwhile, the best conversion efficiency (η = 3.212%) and the average external quantum efficiency (EQE = 51.1% in the visible-wavelength region) of photo-electric properties were achieved for the developed CIGS2-solar cells (CGI = 0.95). The discoveries of this CIGS2-absorption PV research provided a new scientific understanding of solar cells. Moreover, this research undeniably contributes to a major advancement towards practical PV-module applications and can help more to build an eco-friendly community.

19.
J Food Drug Anal ; 31(2): 244-253, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37335167

RESUMO

Green emission carbon dots (CDs) electrochemically prepared from 2,6-pyridinedicarboxylic acid and o-phenyl-enediamine were applied separately for the quantitation of hypochlorite and carbendazim. The characteristic and optical properties of the CDs were studied through fluorescence, UV-vis absorption, X-ray photoelectron spectroscopy, and transmission electron microscopy. The synthesized CDs were mainly 0.8-2.2 nm in size, with an average size of 1.5 nm. The CDs exhibited green luminescence centered at 520 nm when excited by 420 nm light. The green emission of the CDs is quenched after the addition of hypochlorite, mainly through the redox reaction between hypochlorite and hydroxyl groups on the CDs surface. Furthermore, the hypochlorite-induced fluorescence quenched can be prevented in the presence of carbendazim. The sensing approaches exhibit good linear ranges of 1-50 µM and 0.05-5 µM for hypochlorite and carbendazim, respectively, with low detection limits of 0.096 and 0.005 µM, respectively. Practicalities of the luminescent probes were separately validated by the quantitation of the two analytes in real sample matrix with recoveries ranging from 96.3 to 108.9% and the relative standard deviation values below 5.51%. Our results show the potential of the sensitive, selective, and simple CD probe for water and food quality control.


Assuntos
Ácido Hipocloroso , Pontos Quânticos , Pontos Quânticos/química , Carbono , Espectroscopia Fotoeletrônica
20.
Nat Commun ; 14(1): 18, 2023 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-36627269

RESUMO

Extracellular matrix stiffening is a quintessential feature of cartilage aging, a leading cause of knee osteoarthritis. Yet, the downstream molecular and cellular consequences of age-related biophysical alterations are poorly understood. Here, we show that epigenetic regulation of α-Klotho represents a novel mechanosensitive mechanism by which the aged extracellular matrix influences chondrocyte physiology. Using mass spectrometry proteomics followed by a series of genetic and pharmacological manipulations, we discovered that increased matrix stiffness drove Klotho promoter methylation, downregulated Klotho gene expression, and accelerated chondrocyte senescence in vitro. In contrast, exposing aged chondrocytes to a soft matrix restored a more youthful phenotype in vitro and enhanced cartilage integrity in vivo. Our findings demonstrate that age-related alterations in extracellular matrix biophysical properties initiate pathogenic mechanotransductive signaling that promotes Klotho promoter methylation and compromises cellular health. These findings are likely to have broad implications even beyond cartilage for the field of aging research.


Assuntos
Cartilagem Articular , Proteínas Klotho , Osteoartrite do Joelho , Humanos , Cartilagem/metabolismo , Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Epigênese Genética , Osteoartrite do Joelho/metabolismo , Proteínas Klotho/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA