Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 79
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Anal Chem ; 96(8): 3679-3685, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38353671

RESUMO

Recently, organic photoelectrochemical transistor (OPECT) bioanalysis has become a prominent technique for the high-performance detection of biomolecules. However, as a sensitive index of the OPECT, the dynamic regulation transconductance (gm) is still severely deficient. Herein, this work reports a new photosensitive metal-organic framework (MOF-on-MOF) heterostructure for the effective modulation of maximum gm and natural bienzyme interfacing toward choline detection. Specifically, the bidentate ligand MOF (b-MOF) was assembled onto the UiO-66 MOF (u-MOF) by a modular assembly method, which could facilitate the charge separation and generate enhanced photocurrents and offer a biophilic environment for the immobilization of choline oxidase (ChOx) and horseradish peroxidase (HRP) through hydrogen-bonded bridges. The transconductance of the OPECT could be flexibly altered by increased light intensity to maximal value at zero gate bias, and sensitive choline detection was achieved with a detection limit of 0.2 µM. This work reveals the potential of MOF-on-MOF heterostructures for futuristic optobioelectronics.


Assuntos
Técnicas Biossensoriais , Estruturas Metalorgânicas , Estruturas Metalorgânicas/química , Peroxidase do Rábano Silvestre/química , Colina , Técnicas Biossensoriais/métodos
2.
Matern Child Health J ; 27(3): 548-555, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36732464

RESUMO

OBJECTIVES: Joyuus is a culturally diverse, comprehensive online tool designed to address the self-care needs of underserved postpartum women. The tool provides actionable self-care information, knowledge, and skills to improve postpartum health and identifies red flags for when self-care shifts to seeking care. METHODS: We employed a mixed-methods multiphase design to evaluate the Joyuus prototype, including a pre-post evaluation (N = 87) to assess behavioral health outcomes before and after using the tool for a one-month period. 91% completed the post-test (N = 79). The analysis focused on estimation of treatment effect (via 95% confidence intervals) and fitness of instruments in this population. RESULTS: Participants were between 6 months pregnant and one year postpartum, a mean age of 30 years, 100% female, 99% Black, with nearly equal distribution of married (55%) and not married (44%), and above (47%) and below (46%) annual income of $60 K. Key measures saw significant improvement from pre- (mean = 26.44, SD = 5.39) to post (mean = 28.29, SD = 5.26) on the Connor-Davidson Resilience Scale (p < 0.001) Trends toward improvement (not statistically significant) were noted for Depression (EPDS) (p = 0.624) and Anxiety (STAI) (p = 0.286), and no meaningful change on MOS Social Support or COVID-19 Mental Health Impacts Measures. CONCLUSIONS FOR PRACTICE: This pilot study demonstrates that a self-care mobile tool has the potential to address significant health outcomes related to maternal morbidity and mortality. By providing a continuously available companion addressing physical, mental, and real-life questions, it creates value during postpartum for mothers who can often feel overwhelmed or isolated.


Assuntos
COVID-19 , Depressão Pós-Parto , Gravidez , Humanos , Feminino , Adulto , Masculino , Projetos Piloto , Autocuidado , Período Pós-Parto , Internet , Depressão Pós-Parto/terapia
3.
Angew Chem Int Ed Engl ; 62(9): e202215801, 2023 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-36550087

RESUMO

Single-cell protein therapeutics is expected to promote our in-depth understanding of how a specific protein with a therapeutic dosage treats the cell without population averaging. However, it has not yet been tackled by current single-cell nanotools. We address this challenge by the use of a double-barrel nanopipette, in which one lumen was used for electroosmotic cytosolic protein delivery and the other was customized for ionic evaluation of the consequence. Upon injection of protein DJ-1 through the delivery lumen, upregulation of the antioxidant protein could protect neural PC-12 cells against oxidative stress from phorbol myristate acetate exposure, as deduced by targeting of the cytosolic hydrogen peroxide by the detecting lumen. The nanotool developed in this study for single-cell protein therapeutics provides a perspective for future single-cell therapeutics involving different therapeutic modalities, such as peptides, enzymes and nucleic acids.


Assuntos
Terapia Baseada em Transplante de Células e Tecidos , Proteína Desglicase DJ-1 , Íons , Peptídeos , Terapia Baseada em Transplante de Células e Tecidos/métodos , Sistemas de Liberação de Fármacos por Nanopartículas , Proteína Desglicase DJ-1/farmacologia , Proteína Desglicase DJ-1/uso terapêutico , Estresse Oxidativo , Acetato de Tetradecanoilforbol
4.
Angew Chem Int Ed Engl ; 62(29): e202302930, 2023 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-37189290

RESUMO

Single-cell epigenetics is envisioned to decipher manifold epigenetic phenomena and to contribute to our accurate knowledge about basic epigenetic mechanisms. Engineered nanopipette technology has gained momentum in single-cell studies; however, solutions to epigenetic questions remain unachieved. This study addresses the challenge by exploring N6-methyladenine (m6 A)-bearing deoxyribozyme (DNAzyme) confined within a nanopipette for profiling a representative m6 A-modifying enzyme, fat mass and obesity-associated protein (FTO). Electroosmotic intracellular extraction of FTO could remove the m6 A and cause DNAzyme cleavage, leading to the altered ionic current signal. Because the cleavage can release a DNA sequence, we simultaneously program it as an antisense strand against FTO-mRNA, intracellular injection of which has been shown to induce early stage apoptosis. This nanotool thus features the dual functions of studying single-cell epigenetics and programmable gene regulation.


Assuntos
DNA Catalítico , DNA Catalítico/metabolismo , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Regulação da Expressão Gênica , Epigênese Genética , RNA Mensageiro/metabolismo
5.
Eur J Clin Microbiol Infect Dis ; 41(2): 235-243, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34734347

RESUMO

Microbiological confirmation is rare in children with active tuberculosis; therefore, a more accurate test is needed to detect pulmonary tuberculosis in children. In this multicenter study, we evaluated the utility of the Xpert MTB/RIF Ultra (Ultra) on sputum, an assay recommended by the World Health Organization to test for childhood tuberculosis in high-burden settings. Children with symptoms suggestive of tuberculosis were enrolled at three hospitals in China and categorized as having active tuberculosis or nontuberculosis. The sensitivity and specificity of Ultra were 42.1% (48/114) and 99.0% (208/210), respectively. Using three MTB culture results as the reference, the sensitivity of Ultra in the subset of 38 children with culture-positive and 76 children with culture-negative was 68.4% (26/38) and 28.9% (22/76), respectively(p < 0.001). A single MTB culture combined with a single Ultra could detect 54 (54/114,47.4%) cases with active TB, while repeated MTB culture combined with a single Ultra detected 60 (60/114, 52.6%) cases with active TB(p = 0.427). Among 155 children (58 with TB and 97 with RTIs) simultaneously tested with the Ultra and Xpert MTB/RIF (Xpert), the sensitivity of the Xpert (24.1%, 14/58) was lower than that of the Ultra (41.4%, 24/58; p = 0.048). Eight children were found to have rifampin-resistant MTB strains. The Xpert MTB/RIF Ultra assay should be implemented to test for pulmonary tuberculosis in children to achieve higher confirmation rates.


Assuntos
Antibióticos Antituberculose/farmacologia , Rifampina/farmacologia , Escarro/microbiologia , Tuberculose Pulmonar/diagnóstico , Adolescente , Criança , Pré-Escolar , China , Testes Diagnósticos de Rotina , Farmacorresistência Bacteriana/efeitos dos fármacos , Humanos , Lactente , Recém-Nascido , Mycobacterium tuberculosis/efeitos dos fármacos , Estudos Retrospectivos , Sensibilidade e Especificidade , Tuberculose/diagnóstico
6.
Angew Chem Int Ed Engl ; 61(47): e202212752, 2022 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-36173932

RESUMO

Rational utilization of the rich light-bio-matter interplay taking place in single-cell analysis represents a new technological direction in the field. The light-fueled operation is expected to achieve advanced photoelectrochemical (PEC) single-cell analysis with unknown possibilities. Here, a PEC nanoreactor capable of single-cell sampling and near zero-background Faradaic detection of intracellular microRNA (miR) is devised by the construction of a small reaction chamber accommodating the target-triggered hybridization chain reaction for binding the metallointercalator of [Ru(bpy)2 (dppz)]2+ as the signal reporter. Light stimulation of the dsDNA/metallointercalator adduct will induce the generation of photocurrents, underpinning a zero-biased and near zero-background PEC method toward Faradaic detection of non-electrogenic miR at the single-cell level. Using this nanotool, lower miR concentration in the near-nucleus region than that in the main cytosol was revealed.


Assuntos
Técnicas Biossensoriais , MicroRNAs , MicroRNAs/análise , DNA/metabolismo , Hibridização de Ácido Nucleico , Nanotecnologia , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Limite de Detecção
7.
Ann Hum Genet ; 85(2): 92-96, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33026665

RESUMO

OBJECTIVE: To assess the experience on prenatal diagnosis of Miller-Dieker syndrome (MDS) to further delineate the fetal presentation of this syndrome. METHODS: This was a retrospective study. Fetal MDS was diagnosed prenatally by chromosomal microarray (CMA). Clinical data were reviewed for these cases, including maternal characteristics, indications for prenatal diagnosis, sonographic findings, CMA results, and pregnancy outcomes. RESULTS: Four cases were diagnosis as MDS by CMA. The most common sonographic features were ventriculomegaly (3/4) and polyhydramnios (2/4). Deletion sizes ranged from 1.5 to 5.4 Mb. All microdeletions were located at the MDS critical region and showed haploinsufficiency of the YWHAE, CRK, and PAFAH1B1. All patients chose to terminate the pregnancy. Parental chromosome analysis were preformed in three cases and demonstrated that two cases were de novo and one case was caused by inherited derivative chromosomes from parental balanced translocations. CONCLUSION: The most common prenatal ultrasound findings of MDS were ventriculomegaly and polyhydramnios. CMA can improve diagnostic precision for detecting MDS.


Assuntos
1-Alquil-2-acetilglicerofosfocolina Esterase/genética , Proteínas 14-3-3/genética , Lissencefalias Clássicas e Heterotopias Subcorticais em Banda/diagnóstico , Proteínas Associadas aos Microtúbulos/genética , Diagnóstico Pré-Natal , Proteínas Proto-Oncogênicas c-crk/genética , Adulto , Cromossomos/genética , Lissencefalias Clássicas e Heterotopias Subcorticais em Banda/diagnóstico por imagem , Lissencefalias Clássicas e Heterotopias Subcorticais em Banda/genética , Lissencefalias Clássicas e Heterotopias Subcorticais em Banda/patologia , Feminino , Haploinsuficiência/genética , Humanos , Hidrocefalia/diagnóstico , Hidrocefalia/diagnóstico por imagem , Hidrocefalia/genética , Hidrocefalia/patologia , Análise em Microsséries , Poli-Hidrâmnios/diagnóstico , Poli-Hidrâmnios/diagnóstico por imagem , Poli-Hidrâmnios/genética , Poli-Hidrâmnios/patologia , Gravidez , Ultrassonografia , Adulto Jovem
8.
Anal Chem ; 93(4): 2706-2712, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33426877

RESUMO

Accurate and sensitive detection of targets in practical biological matrixes such as blood, plasma, serum, or tissue fluid is a frontier issue for most biosensors since the coexistence of both potential reducing agents and protein molecules has the possibility of causing signal interference. Herein, aiming at detection in a complex environment, an advanced and robust peptide-based photocathodic biosensor, which integrated a recognition peptide with an antifouling peptide in one probe electrode, was first proposed. Selecting human chorionic gonadotropin (hCG) as a model target, the recognition peptide with the sequence PPLRINRHILTR was first anchored on the CuBi2O4/Au (CBO/Au) photocathode and then the antifouling peptide with the sequence EKEKEKEPPPPC was further anchored to generate an antifouling biointerface. The peptide-based photocathodic biosensor demonstrated excellent anti-interference to both nonspecific proteins and reducing agents because of the capability of the antifouling peptide. It also exhibited good sensitivity owing to the utilization of the recognition peptide rather than an antibody probe. This peptide-integrated method offers a new perspective for practical applications of photocathodic biosensors.


Assuntos
Técnicas Biossensoriais/instrumentação , Peptídeos/química , Fotoquímica/instrumentação , Incrustação Biológica , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Eletrodos , Proteínas Imobilizadas/química , Microscopia Eletrônica de Varredura , Fotoquímica/métodos , Espectroscopia Fotoeletrônica , Sensibilidade e Especificidade , Propriedades de Superfície
9.
Anal Chem ; 93(2): 1200-1208, 2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33301293

RESUMO

Engineered nanopipette tools have recently emerged as a powerful approach for electrochemical nanosensing, which has major implications in both fundamental biological research and biomedical applications. Herein, we describe a generic method of target-triggered assembly of aptamers in a nanopipette for nanosensing, which is exemplified by sensitive and rapid electrochemical single-cell analysis of adenosine triphosphate (ATP), a ubiquitous energy source in life and important signaling molecules in many physiological processes. Specifically, a layer of thiolated aptamers is immobilized onto a Au-coated interior wall of a nanopipette tip. With backfilled pairing aptamers, the engineered nanopipette is then used for probing intracellular ATP via the ATP-dependent linkage of the split aptamers. Due to the higher surface charge density from the aptamer assembly, the nanosensor would exhibit an enhanced rectification signal. Besides, this ATP-responsive nanopipette tool possesses excellent selectivity and stability as well as high recyclability. This work provides a practical single-cell nanosensor capable of intracellular ATP analysis. More generally, integrated with other split recognition elements, the proposed mechanism could serve as a viable basis for addressing many other important biological species.


Assuntos
Trifosfato de Adenosina/análise , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais , Técnicas Eletroquímicas , Análise de Célula Única , Células Cultivadas , Ouro/química , Humanos
10.
Am J Geriatr Psychiatry ; 29(1): 15-23, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32912805

RESUMO

OBJECTIVES: Alcohol and substance misuse has been under-acknowledged and underidentified in older adults. However, promising treatment approaches exist (e.g., brief interventions) that can support older adults with at-risk alcohol and substance use. Postacute rehabilitation settings of Skilled Nursing Facilities (SNFs) can offer such programs, but little is known about patient characteristics that are associated with the likelihood of participating in interventions offered in postacute rehabilitation care. Thus, the objective of this study was to identify individual patient characteristics (predisposing, enabling, and need-related factors) associated with participation in a brief alcohol and substance misuse intervention at a SNF. METHODS: This cross-sectional study analyzed medical record data of postacute care patients within a SNF referred to a substance misuse intervention. Participants were 271 patients with a history of substance misuse, 177 of whom enrolled in the intervention and 94 refused. Data collected upon patient admission were used to examine predisposing, enabling, and need-related factors related to likelihood of program participation. RESULTS: Older age and ethnic minority status were associated with a reduction in likelihood to participate, while widowhood increased the likelihood of participation. CONCLUSION: Upon referral to a substance misuse intervention, clinicians in SNFs should be cognizant that some patients may be more likely to refuse intervention, and additional efforts should be made to engage patients at-risk for refusal.


Assuntos
Instituições de Cuidados Especializados de Enfermagem , Cuidados Semi-Intensivos , Transtornos Relacionados ao Uso de Substâncias/terapia , Recusa do Paciente ao Tratamento/estatística & dados numéricos , Idoso , Estudos Transversais , Etnicidade/estatística & dados numéricos , Feminino , Humanos , Masculino , Grupos Minoritários/estatística & dados numéricos , Cuidados Semi-Intensivos/psicologia , Transtornos Relacionados ao Uso de Substâncias/psicologia , Recusa do Paciente ao Tratamento/psicologia , Viuvez/estatística & dados numéricos
11.
Angew Chem Int Ed Engl ; 60(24): 13244-13250, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-33340231

RESUMO

New tools for single-cell interrogation enable deeper understanding of cellular heterogeneity and associated cellular behaviors and functions. Information of RNA expression in single cell could contribute to our knowledge of the genetic regulatory circuits and molecular mechanism of disease development. Although significant progresses have been made for intracellular RNA analysis, existing methods have a trade-off between operational complexity and practical feasibility. We address this challenge by combining the ionic current rectification property of nanopipette reactor with duplex-specific nuclease-assisted hybridization chain reaction for signal amplification to realize a simple and practical intracellular nanosensor with minimal invasiveness, which enables single-cell collection and electrochemical detection of intracellular RNA with cell-context preservation. Systematic studies on differentiation of oncogenic miR-10b expression levels in non-malignant breast cells, metastatic breast cancer cells as well as non-metastatic breast cancer cells were then realized by this nanotool accompanied by assessment of different drugs effects. This work has unveiled the ability of electrochemistry to probe intracellular RNA and opened new opportunities to study the gene expression and heterogeneous complexity under physiological conditions down to single-cell level.


Assuntos
Técnicas Eletroquímicas/métodos , Nanotecnologia/instrumentação , RNA/análise , Análise de Célula Única , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Regulação para Baixo/efeitos dos fármacos , Condutividade Elétrica , Técnicas Eletroquímicas/instrumentação , Humanos , MicroRNAs/análise , MicroRNAs/metabolismo , Microscopia de Fluorescência , RNA/metabolismo
12.
BMC Evol Biol ; 20(1): 156, 2020 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-33228518

RESUMO

BACKGROUND: Ecdysozoa are the moulting protostomes, including arthropods, tardigrades, and nematodes. Both the molecular and fossil records indicate that Ecdysozoa is an ancient group originating in the terminal Proterozoic, and exceptional fossil biotas show their dominance and diversity at the beginning of the Phanerozoic. However, the nature of the ecdysozoan common ancestor has been difficult to ascertain due to the extreme morphological diversity of extant Ecdysozoa, and the lack of early diverging taxa in ancient fossil biotas. RESULTS: Here we re-describe Acosmia maotiania from the early Cambrian Chengjiang Biota of Yunnan Province, China and assign it to stem group Ecdysozoa. Acosmia features a two-part body, with an anterior proboscis bearing a terminal mouth and muscular pharynx, and a posterior annulated trunk with a through gut. Morphological phylogenetic analyses of the protostomes using parsimony, maximum likelihood and Bayesian inference, with coding informed by published experimental decay studies, each placed Acosmia as sister taxon to Cycloneuralia + Panarthropoda-i.e. stem group Ecdysozoa. Ancestral state probabilities were calculated for key ecdysozoan nodes, in order to test characters inferred from fossils to be ancestral for Ecdysozoa. Results support an ancestor of crown group ecdysozoans sharing an annulated vermiform body with a terminal mouth like Acosmia, but also possessing the pharyngeal armature and circumoral structures characteristic of Cambrian cycloneuralians and lobopodians. CONCLUSIONS: Acosmia is the first taxon placed in the ecdysozoan stem group and provides a constraint to test hypotheses on the early evolution of Ecdysozoa. Our study suggests acquisition of pharyngeal armature, and therefore a change in feeding strategy (e.g. predation), may have characterised the origin and radiation of crown group ecdysozoans from Acosmia-like ancestors.


Assuntos
Fósseis , Invertebrados , Filogenia , Animais , Artrópodes/anatomia & histologia , Artrópodes/classificação , Teorema de Bayes , China , Invertebrados/anatomia & histologia , Invertebrados/classificação , Nematoides/anatomia & histologia , Nematoides/classificação , Tardígrados/anatomia & histologia , Tardígrados/classificação
13.
J Am Chem Soc ; 142(42): 17892-17896, 2020 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-33044060

RESUMO

The exploitation of singlet fission (SF) in photovoltaic devices is restricted by the limited number of SF materials available and the conflicting requirement of intermolecular interactions to satisfy both efficient SF and subsequent triplet extraction. Intramolecular SF (iSF) represents an emerging alternative and may prove simpler to implement in devices. On account of the excellent chemical structure tunability and solution processability, conjugated polymers have emerged as promising candidates for iSF materials despite being largely underexplored. It remains a significant challenge to develop SF-capable conjugated polymers and achieve efficient dissociation of the formed triplet pairs simultaneously. In this contribution, we present a new iSF material in a para-azaquinodimethane-based quinoidal conjugated polymer. Using transient optical techniques, we show that an ultrafast iSF process dominates the deactivation of the excited state in such polymer, featuring ultrafast population (<1 ps) and stepwise dissociation of triplet pairs. Notably, these multiexciton states could further diffuse apart to produce long-lived free triplets (tens of µs) in strongly coupled aggregates in solid thin film. Such findings not only introduce a new iSF-active conjugated polymer to the rare SF material family but also shed unique insight into interchain interaction-promoted triplet pair dissociation in aggregates of conjugated polymers, thus openning new avenues for developing next-generation SF-based photovoltaic materials.

14.
J Clin Microbiol ; 58(9)2020 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-32522831

RESUMO

A multicenter study was performed to evaluate the value of testing gastric aspirate (GA) with Xpert MTB/RIF Ultra assay (Ultra) for childhood tuberculosis (TB) detection in China. In total, 129 children with active TB and 173 children without TB were enrolled. The sensitivity of Ultra in bacteriologically confirmed TB and probable TB cases was 87.5% (42/48) and 44.4% (36/81), respectively. The specificity of Ultra was high (99.4%, 172/173). When Ultra, culture, and acid-fast bacilli outcomes were integrated as a composite reference standard, the percentage of children with definite TB increased from 37.2% (48/129) to 67.4% (87/129). The sensitivity of Ultra is 80.0% (40/50) in children aged <4 years, which is significantly higher than that in older children (48.1%, 38/79) (P < 0.001). Ultra conducted using GA samples can provide faster results, allowing an early and accurate TB diagnosis, especially in younger children with difficulty producing sputum.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Criança , Pré-Escolar , China , Humanos , Mycobacterium tuberculosis/genética , Sensibilidade e Especificidade , Escarro , Tuberculose/diagnóstico
15.
Anal Chem ; 91(10): 6403-6407, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-31062591

RESUMO

Energy transfer (ET) in photoelectrochemical (PEC) bioanalysis is usually generated between noble metal nanoparticles (NPs) and traditional inorganic quantum dots (QDs). Using the innovative polymer dot (Pdot)-involved ET, this work reports the first signal-on and cathodic PEC bioanalysis toward telomerase (TE) activity in cell extracts. Specifically, the sequential binding of capture DNA (cDNA), telomerase primer sequence (TS), and Au NP-labeled probe DNA (Au NP-pDNA) on the electrode would place the Au NPs in close proximity of the Pdots, leading to obvious quenching of the cathodic photocurrent. The subsequent extension of the TS by TE in the presence of deoxyribonucleoside triphosphates (dNTPs) would then release the Ag NP-pDNA from the electrode, leading to the recovery of the photocurrent. On the basis of the Au NP-induced photocurrent quenching and the recovery of Pdots, a sensitive biosensor could thus be developed by tracking the photocurrents to probe the TE activity. This strategy allows for signal-on and cathodic PEC bioanalysis of TE, which can be easily extended for numerous other targets of interest. We believe this work could offer a new perspective for the rational implementation of Pdot-involved ET for advanced PEC bioanalysis.


Assuntos
Transferência de Energia , Ouro/química , Nanopartículas Metálicas/química , Pontos Quânticos , Telomerase/metabolismo , Técnicas Biossensoriais , Extratos Celulares , Técnicas Eletroquímicas , Células HeLa , Humanos , Processos Fotoquímicos , Telomerase/química
16.
Transfusion ; 59(1): 385-395, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30520533

RESUMO

BACKGROUND: Alloanti-M was once regarded as not clinically significant, with a few exceptions in extremely rare cases. However, an increasing number of cases of severe hemolytic disease of the fetus and newborn (HDFN), resulting in fetal hydrops and recurrent abortion caused by alloanti-M, have been reported mainly in the Asian population. STUDY DESIGN AND METHODS: Three pregnant Chinese women with a history of abnormal pregnancy with hydrops fetalis were encountered. During this pregnancy, a series of clinical examinations and an alloantibody identification against RBCs and platelets were conducted. Intrauterine transfusion and postnatal transfusion were then performed in the fetuses. In addition, the HDFN cases caused by alloanti-M reported in different ethnic groups as well as their clinical and serologic features are also summarized. RESULTS: Three pregnant women were identified with an M-N+ phenotype and IgM mixed with IgG alloanti-M in serum. Their fetuses were found by ultrasound examination and cord blood testing to have severe anemia. Additionally, an M+N+ phenotype and IgG alloanti-M were detected in the cord blood of the three fetuses with titers ranging from 1:1 to 1:128. Moreover, low reticulocyte counts and negative direct antiglobulin tests were also shown in two of the fetuses. After receiving intrauterine transfusions and postnatal transfusions several times, these three fetuses eventually survived and then healthfully developed in the follow-up tracking. CONCLUSION: Alloanti-M immunization can cause severe HDFN with hyporegenerative anemia, often seen in the Asian population, and suppression of erythropoiesis might account for it.


Assuntos
Eritroblastose Fetal/patologia , Anemia/patologia , Transfusão de Sangue Intrauterina , Eritropoese/fisiologia , Feminino , Feto , Humanos , Recém-Nascido , Masculino , Gravidez , Reticulócitos/patologia
17.
Anal Chem ; 90(20): 11892-11898, 2018 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-30229657

RESUMO

Highly stable circulating microRNAs (miRNAs) are currently recognized as a novel potential biomarker for clinical cancer diagnosis in the early stage. However, limited by its low concentration, high sequence similarity, as well as the numerous interferences in body fluids, detection of miRNA in whole blood with sufficient selectivity and sensitivity is still challenging. Herein, we reported the integration of entropy-driven toehold-mediated DNA strand displacement (ETSD) reaction with magnetic beads (MB) toward the energy-transfer-based photoelectrochemical (PEC) detection of the prostate carcinoma (PCa) biomarker miRNA-141 in a real blood sample. In this protocol, the ETSD reaction was divided into two steps, and cooperated with magnetic separation, target extraction and amplification could be realized in a single test and ultrasensitive detection of miRNA-141 could be achieved in undiluted whole blood sample. This work proposed a new solution for sensitive biomolecular detection in a complex biological milieu and exhibited great promise for future clinical cancer diagnosis.


Assuntos
DNA/química , Técnicas Eletroquímicas , Entropia , Ouro/química , Magnetismo , Nanopartículas Metálicas/química , MicroRNAs/sangue , Microesferas , Eletrodos , Fluorescência , Humanos , Tamanho da Partícula , Processos Fotoquímicos , Propriedades de Superfície
18.
Anal Chem ; 90(7): 4277-4281, 2018 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-29528617

RESUMO

We report herein the energy transfer (ET) between semiconducting polymer dots (Pdots) and gold nanoparticles (Au NPs) in a photoelectrochemical (PEC) system and its feasibility for cathodic bioanalysis application. Specifically, COOH-capped Pdots were first fabricated and then assembled onto the indium-tin oxide (ITO) surface, followed by the modification of single-strand (ss) DNA probe (pDNA). After the DNA hybridization with the Au NP-tethered complementary ssDNA (Au NP-tDNA), the Au NPs were brought into the close proximity of Pdots. Upon light stimulation, photoluminescence (PL) was annihilated, fluorescence was attenuated, and the photocurrent intensity was evidently decreased. This ET-based PEC DNA sensor exhibited a linear range from 1 fM to 10 pM with a detection limit of 0.97 fM at a signal-to-noise ratio of 3. The present work first exploited the ET between Pdots and Au NPs, and we believe this phenomenon will spark new interest in the study of various Pdots-based ET-influenced PEC systems and thus catalyze increasing studies for specific bioanalytical purposes.

19.
Anal Chem ; 90(14): 8300-8303, 2018 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-29956537

RESUMO

This work reported the photoelectrochemical (PEC) pH sensor for sensitive and broad-range pH measurement on the basis of semiconducting polymer dots (Pdots). The sensor was fabricated by immobilizing Pdots onto the surface of indium tin oxide (ITO). Experimental results revealed that the carboxylic acid groups of Pdots were sensitive to pH variation, which could result in conformational changes and further diffusion of carriers. Besides, different pH value could change the redox properties of the Pdots, and the photocurrent response was hence altered by the carriers produced on the Pdots. Further results demonstrated that the developed sensor exhibited variable photocurrent sensitively by responding to different pH values. This pH sensor is of high sensitivity, stability, and reversibility, which provides a bright prospect for future pH measurements in the bioanalytical field.

20.
Anal Chem ; 90(16): 9687-9690, 2018 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-30078328

RESUMO

This work reports the development of three-dimensional (3D) semiconducting polymer/graphene (SP/G) networks toward sensitive photocathodic enzymatic bioanalysis. Specifically, the porous 3D graphene was first synthesized via the hydrothermal and freeze-dry processes and then mixed with semiconducting polymer to obtain the designed hierarchical structure with unique porosity and large surface area. Afterward, the as-prepared hybrid was immobilized onto the indium tin oxide (ITO) for further characterizations. Exemplified by sarcosine oxidase (SOx) as a model biocatalyst, an innovative 3D SP/G-based photocathodic bioanalysis capable of sensitive and specific sarcosine detection was achieved. The suppression of cathodic photocurrent was observed in the as-developed photocathodic enzymatic biosystem due to the competition of oxygen consumption between the enzyme-biocatalyst process and O2-dependent photocathodic electrode. This work not only presented a unique protocol for 3D SP/G-based photocathodic enzymatic bioanalysis but also provided a new horizon for the design, development, and utilization of numerous 3D platforms in the broad field of general photoelectrochemical (PEC) bioanalysis.


Assuntos
Fluorenos/química , Grafite/química , Maleatos/química , Polímeros/química , Poliestirenos/química , Sarcosina Oxidase/química , Sarcosina/análise , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Eletrodos , Enzimas Imobilizadas/química , Fluorenos/efeitos da radiação , Grafite/síntese química , Luz , Maleatos/efeitos da radiação , Processos Fotoquímicos , Polímeros/efeitos da radiação , Poliestirenos/efeitos da radiação , Porosidade , Compostos de Estanho/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA