RESUMO
It is valuable to develop a sensing platform for not only detecting a tumor marker in body fluids but also measuring its expression at single cells. In the present study, a simple closed bipolar electrodes-based electrochemiluminescence (BPEs-ECL) imaging strategy was developed for visual immunoassay of prostate specific antigen (PSA) at single cells using functional nanoprobes of heterogeneous Ru(bpy)32+@SiO2/Au nanoparticles. Multiple-assisted ECL signal amplification strategy was introduced into the detection system on the basis of the synergetic amplifying effect of the anodic and cathodic amplification. On the basis of the synergetic amplifying effect, the detection limits of PSA by using photomultiplier tube and charge-coupled device (CCD) imaging are 3.0 and 31 pg/mL, respectively. The obtained immunosensor was employed to evaluate PSA levels in serum samples with a satisfying result. Moreover, the obtained functional nanoprobes were used to visually profile the PSA expression on the surface of single LNCaP cells (a kind of prostate cancer cells) based on a bare BPE. The results show that the functional nanoprobes-based ECL imaging immunoassay provides a promising visual platform for detecting tumor markers (proteins and cancer cells) and thus shows a high potential in cancer diagnosis.
Assuntos
Técnicas Eletroquímicas/métodos , Ouro/química , Imunoensaio/métodos , Nanopartículas Metálicas/química , Compostos de Rutênio/química , Dióxido de Silício/química , Análise de Célula Única/métodos , Biomarcadores Tumorais/análise , Técnicas Biossensoriais , Linhagem Celular Tumoral , Eletrodos , Humanos , Limite de Detecção , Luminescência , Antígeno Prostático Específico/análiseRESUMO
The outbreak of the 2019 novel coronavirus disease (COVID-19) has impacted the mental health of healthcare providers at the frontline. Therefore, we conducted this study to estimate the prevalence rate of anxiety and insomnia and identify associated risk factors among healthcare workers in Jilin, China, during the period from January 25 to February 25, 2020. Zung's Self-Reported Anxiety Scale (SAS) and the Insomnia Severity Index (ISI) scale were used to diagnose anxiety and insomnia, respectively. Associated risk factors were identified through a multivariate logistic regression model. A total of 300 healthcare workers were invited and 236 completed the study. Of them, 234 (99.15%) were medical workers, 197 (83.47%) were working at frontline departments, and 159 (67.37%) were fighting against COVID-19. Fifty-seven respondents (24.15%) had anxiety (SAS index score ≥45) and 94 (39.83%) had insomnia (ISI score ≥8). Based on the multivariate analysis, contact with people from Hubei province during work (no vs not clear) [OR=0.25, 95%CI: 0.10-0.61] and personal protective equipment (PPE) (not in place vs in place) [OR=6.22, 95%CI: 2.23-17.40] were significantly correlated with anxiety. PPE (not in place vs in place) was the only significant risk factor of insomnia [OR=10.56, 95%CI: 4.00-27.87]. The prevalence of anxiety and insomnia was high in our study, reflecting the psychological impact of COVID-19 on healthcare workers. The unavailability of PPE in place was a significant risk factor of both anxiety and insomnia.
Assuntos
COVID-19 , Distúrbios do Início e da Manutenção do Sono , Ansiedade/epidemiologia , China/epidemiologia , Estudos Transversais , Depressão , Pessoal de Saúde , Humanos , Pandemias , Prevalência , SARS-CoV-2 , Distúrbios do Início e da Manutenção do Sono/epidemiologiaRESUMO
Photoactive materials with high photo-electron transfer efficiency and stable signal output hold a key role in constructing the photoelectrochemical (PEC) biosensing systems. In this study, the ternary CdS@Au-g-C3N4 heterojunction was first prepared and characterized, and its application in PEC bioanalysis was explored. The gold nanoparticles sandwiched between CdS and g-C3N4, acting as both plasmonic photosensitizer and electron relay, significantly boosted the light absorption and accelerated the charge transfer from g-C3N4 to CdS, both of which contributed to the enhancement of photoelectric conversion efficiency. Signal quenching with graphene oxide-CuS efficiently weakened the photocurrent from CdS@Au-g-C3N4. The combination of the excellent PEC properties of CdS@Au-g-C3N4 and the remarkable quenching effects of graphene oxide-CuS enabled construction of a sandwich-type PEC immunosensor for prostate specific antigen (PSA) detection. This immunosensor achieved sensitive PSA analysis by multiple signal amplification mechanisms, with a detection limit of 0.6 pg mL-1 and a wide linear range from 1.0 pg mL-1 to 10 ng mL-1. This work not only demonstrates the great potential of noble metal sandwiched ternary heterojunctions in the PEC field, but also lays a foundation for developing the general PEC immunoassays.
Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Imunoensaio , Antígeno Prostático Específico/análise , Compostos de Cádmio/química , Cobre/química , Ouro/química , Grafite/química , Humanos , Compostos de Nitrogênio/química , Tamanho da Partícula , Processos Fotoquímicos , Sulfetos/química , Propriedades de SuperfícieRESUMO
The exploration of advanced photoactive materials with fine photoelectrochemical (PEC) performance is always the hot subject in PEC bioanalysis. Herein, Mn-doped CdS nanocrystals (CdS:Mn)-sensitized 2D/2D heterostructured g-C3N4-MoS2 was prepared and served as photoactive matrix of PEC sensing platform for myoglobin (Myo) detection using CuO nanoparticles labeled anti-Myo (anti-Myo-CuO) conjugates as signal amplification tags. The heterostructured g-C3N4-MoS2 could effectively promote the electron transfer and evidently restrain the recombination of electron-hole pairs, producing the high photocurrent response. Upon loaded CdS:Mn on the heterostructured g-C3N4-MoS2 to form co-sensitized structure, the photocurrent further gives a dramatically increase. To proof the performance of the co-sensitized structure in PEC bioanalysis, a sandwich type PEC immunosensor was designed by using the co-sensitized structure as photomatrix, Myo as model protein, and anti-Myo-CuO conjugates as amplifying tags. The introduction of anti-Myo-CuO conjugates in this system could significantly quench the PEC response of the sensing interface owing to the competition of the light-generated electron, poor conductivity and steric hindrance of the anti-Myo-CuO conjugates. In virtue of synergistic amplification of the CdS:Mn sensitized heterostructured g-C3N4-MoS2 and the anti-Myo-CuO conjugates, the immunosensor could respond down to 0.42â¯pgâ¯mL-1 Myo with a detectable range of 1.0â¯pgâ¯mL-1 to 50â¯ngâ¯mL-1. Moreover, this PEC platform demonstrates high specificity and sensitivity for Myo detection in real biological matrices. This strategy may furnish new insights for applications of novel 2D/2D heterostructures in PEC bioanalysis.
RESUMO
Land urbanization can affect carbon sequestration. In this study, the relationships between land urbanization and carbon sequestration of urban vegetation were studied for Guangzhou, China. The methodology was based on land use data from Thematic Mapper (TM) imagery, MODIS13Q1 data, and climate data, and the improved Carnegie-Ames-Stanford approach (CASA) model and linear system models were employed. Characteristics such as the amount of expansion, spatial agglomeration, spatial expansion intensity, and spatial growth of built-up land were analyzed, and the influence of land urbanization (built-up land expansion) on carbon sequestration of urban vegetation was elucidated by a temporal sequential cooperativity analysis. The main results were as follows. (1) Land urbanization had a clear influence on carbon sequestration of urban vegetation in Guangzhou, and the proportion and spatial agglomeration of built-up land showed significant negative correlations with this carbon sequestration; the correlation coefficients were -0.443 and -0.537, respectively, in 2014. (2) The spatial expansion intensity and spatial growth of built-up land showed small correlations with carbon sequestration, and the correlations from 2000 to 2005 were relatively larger than those at other times; this was because the built-up land expansion speed was the fastest during this period. (3) The temporal sequential cooperativity analysis revealed that carbon was lost as natural surfaces were transformed to artificial surfaces, and land urbanization effects on carbon sequestration showed no significant temporal lag. Carbon sequestration of urban vegetation in the city could be improved by adding urban green spaces; however, this would likely take some time as the system recovers.
RESUMO
Locations of city features, e.g., city centers, roads, railways, and rivers, may impact urban carbon sinks. Therefore, the effects of city features on spatial variations of urban carbon sinks were investigated using geographic proximity data. The main results were as follows. (1) Carbon sink function varied in a complex manner with distance from the city center and with city size. The carbon sink per unit area increased with distance from the prefecture-level city center (0-30â¯km), with the dominant influence occurring within a 9â¯km radius. The lowest carbon sink per unit area was observed at a distance of 12â¯km from the city center of the provincial capital city (Guangzhou) and special economic zone (Shenzhen), which may be suburban industrial zones. (2) Carbon sinks decreased with increases in road grades as a result of the different functions and traffic flow, and carbon sinks were lowest near city express ways. For highways, carbon sinks were lower near highway entrances and exits. Carbon sinks around ordinary railways were higher than those around subways and light rail, but carbon sink characteristics grew more complex with increasing distances from subways and light rail. (3) Rivers were closely related to the urban layout. Grade I (i.e., larger) rivers were associated with lower carbon sinks, and carbon sink characteristics became increasingly complex around larger rivers. Within a 0-1000â¯m distance of all rivers, the carbon sink per unit area increased rapidly, but carbon sink characteristics differed slightly for grade I rivers. This study implies that it is important to take urbanization spatial position effects into account while assessing regional carbon sinks during urbanization and development.
Assuntos
Sequestro de Carbono/fisiologia , Geografia , Urbanização , China , Cidades , Ecossistema , RiosRESUMO
This work reports the elegant bridging of enzymatic generation of electron donor with photogenerated hole-induced chemical redox cycling amplification (RCA) for innovative photoelectrochemical (PEC) immunoassay, by the aid of a heterojunction photoelectrode with split-type strategy. Specifically, the system was exemplified by the alkaline phosphatase (ALP) catalytic generation of ascorbic acid (AA), the redox cycling of AA by tris (2-carboxyethyl) phosphine (TCEP) as reductant, and the use of a novel Bi2S3/Bi2Sn2O7 heterojunction and myoglobin (Myo) as the photoelectrode and the target, respectively. After the immunoreaction and ALP-induced production of AA, the subsequent oxidation of AA by the photogenerated holes of the Bi2S3/Bi2Sn2O7 heterojunction could be cycled via the regeneration of AA by TCEP from the oxidized product of dehydroascorbic acid, leading to easy signal amplification for the sensitive immunoassay of Myo in real samples. It is believed that this work provided a basis for further design and development of general RCA-based PEC immunoassays.
Assuntos
Técnicas Biossensoriais , Bismuto/química , Técnicas Eletroquímicas , Imunoensaio , Mioglobina/sangue , Sulfetos/química , Compostos de Estanho/química , Humanos , Oxirredução , Tamanho da Partícula , Processos Fotoquímicos , Porosidade , Propriedades de SuperfícieRESUMO
The detection of biomarkers with high sensitivity and accuracy in real biosamples remains challenging. Herein, a universal spatial-resolved photoelectrochemical (PEC) ratiometry for biodetection of prostate-specific antigen (PSA) as model biomarker was designed for the first time based on a dual-electrode array modified by CdS@g-C3N4 heterojunction coupled with CuS quantum dots (QDs) as signal amplification tags. Specifically, a new kind of photoactive material, the CdS@g-C3N4 p-n heterojunction with high photoelectric conversion efficiency and good chemical stability, was synthesized and immobilized on two spatial-resolved electrodes (WE1 and WE2). After immobilizing gold nanoparticles and capturing PSA antibodies on the electrodes, WE1 incubated with various concentrations of PSA was taken as a working electrode, whereas WE2 with a fixed concentration of PSA was used as an internal reference electrode. Next, signal antibodies of PSA-labeled CuS QDs as PEC signal quenchers were immobilized on the electrodes to form a sandwich-type immunocomplex. With the aid of a multiplexed disjunctor, the PEC responses of the dual electrodes were recorded, and the PSA was quantified via the ratio values of photocurrent intensities from WE1 and WE2. Combining the fine PEC performance of the CdS@g-C3N4 heterojunction with the superior quenching effect of CuS QDs in the spatial-resolved platform, the ratiometric system exhibits a linear range from 1.0 × 10-11 to 5.0 × 10-8 g mL-1 with a limit of detection of 4.0 pg mL-1. The results demonstrated herein may provide a new pattern for biomarker detection with high accuracy and good specificity as well as satisfactory applicability in real biosamples.
RESUMO
An ascorbic acid oxidase (AAO)-ascorbic acid bioevent-based electron donor consumption mode was introduced into the PEC bioassay for the first time. Ternary hybrid bismuth sulfide/silver sulfide/TiO2 nanotube arrays as the photoelectrode coupled with AAO attached to SiO2 as a dual signal quenching strategy were employed for sensitivity enhancement.
Assuntos
Ascorbato Oxidase/química , Ácido Ascórbico/química , Técnicas Biossensoriais , Técnicas Eletroquímicas , Elétrons , Nanotecnologia , Ascorbato Oxidase/metabolismo , Ácido Ascórbico/metabolismo , Bismuto/química , Nanotubos/química , Processos Fotoquímicos , Compostos de Prata/química , Sulfetos/química , Titânio/químicaRESUMO
Herein, a novel photoelectrochemical (PEC) immunosensing platform for highly sensitive detection of prostate specific antigen (PSA) was constructed based on dual-quenching of photocurrent from CdSe sensitized TiO2 electrode by gold nanoparticles decorated dopamine-melanin nanospheres (AuNPs-Dpa-melanin CNSs). In this proposal, CdSe sensitized TiO2 was used as photoelectrochemical matrix and the functional AuNPs-Dpa-melanin CNSs were used as signal quenching element. The dual quenching of the gold nanoparticles decorated Dpa-melanin CNSs to the CdSe sensitized TiO2 was achieved as follows: (i) the strong energy transfer between the CdSe quantum dots (QDs) and Au NPs diminishes the photocurrent signal of CdSe QDs; (ii) the steric hindrance of AuNPs-Dpa-melanin CNSs partly obstructs the diffusion of the electron donor, i.e. ascorbic acid, to the surface of photoelectrode, which make the depleting efficiency of the photogenerated holes decrease, leading to a declined photocurrent intensity. On the basis of the dual quenching effect of AuNPs-Dpa-melanin CNSs, a competitive immunosensing platform for PSA was designed upon the specific binding of anti-PSA to PSA and PSA functionalized AuNPs-Dpa-melanin CNSs conjugates. This proposed immunosensor possesses wide linear range from 1.0×10-11gmL-1 to 1.0×10-7gmL-1 with the detection limit of 2.7pgmL-1. Moreover, the applicability of the present method was demonstrated in the determination of PSA in human serum. The strategy creates new paradigms for PSA and other tumor markers detection and demonstrates high sensitivity, good specificity, and satisfied applicability in complex biological samples.
Assuntos
Compostos de Cádmio/química , Técnicas Eletroquímicas/instrumentação , Ouro/química , Indóis/química , Nanopartículas/química , Polímeros/química , Antígeno Prostático Específico/sangue , Compostos de Selênio/química , Titânio/química , Anticorpos Imobilizados/química , Técnicas Biossensoriais/instrumentação , Eletrodos , Humanos , Imunoensaio/instrumentação , Limite de Detecção , Melaninas/química , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Nanopartículas/ultraestrutura , Nanosferas/química , Nanosferas/ultraestrutura , Processos FotoquímicosRESUMO
Sensitized titanium-oxo clusters (TOCs) have attracted growing interest. However, reports on TOCs incorporated with a metal complex as photosensitizers are still very rare. In the present work, the organometallic complex ferrocene was used as a sensitizer for a titanium-oxo cluster. A ferrocenecarboxylate-substituted titanium-oxo cluster [Ti6(µ3-O)6(OiPr)6(O2CFc)6] (Fc = ferrocenyl) was synthesized and structurally characterized, in which the ferrocene wheel performs as a sensitizer for photocurrent response. For comparison, naphthalene-sensitized titanium-oxo clusters [Ti6(µ3-O)6(OiPr)6(NA)6] (NA = 1-naphthoate) and [Ti6(µ3-O)6(OiPr)6(NAA)6] (NAA = 1-naphthylacetate) with the same {Ti6} core structure were also synthesized. The structures, optical behaviors, electronic states and photoelectrochemical properties of these sensitized {Ti6} clusters were investigated. It is demonstrated that the introduction of ferrocene groups into the titanium-oxo cluster significantly reduces the band gap and enhances the photocurrent response in comparison with the naphthalene-sensitized clusters. The substantially reduced band gap of the ferrocene-sensitized cluster was attributed to the introduction of Fe(ii) d-d transitions and the possible contribution from the Fc â {Ti6} charge transfer. For the naphthalene-sensitized clusters, the better electronic coupling between the dye and the {Ti6} core in the 1-naphthoate (NA) substituted cluster results in higher photoelectrochemical activity.
RESUMO
The outbreak of the 2019 novel coronavirus disease (COVID-19) has impacted the mental health of healthcare providers at the frontline. Therefore, we conducted this study to estimate the prevalence rate of anxiety and insomnia and identify associated risk factors among healthcare workers in Jilin, China, during the period from January 25 to February 25, 2020. Zung's Self-Reported Anxiety Scale (SAS) and the Insomnia Severity Index (ISI) scale were used to diagnose anxiety and insomnia, respectively. Associated risk factors were identified through a multivariate logistic regression model. A total of 300 healthcare workers were invited and 236 completed the study. Of them, 234 (99.15%) were medical workers, 197 (83.47%) were working at frontline departments, and 159 (67.37%) were fighting against COVID-19. Fifty-seven respondents (24.15%) had anxiety (SAS index score ≥45) and 94 (39.83%) had insomnia (ISI score ≥8). Based on the multivariate analysis, contact with people from Hubei province during work (no vs not clear) [OR=0.25, 95%CI: 0.10-0.61] and personal protective equipment (PPE) (not in place vs in place) [OR=6.22, 95%CI: 2.23-17.40] were significantly correlated with anxiety. PPE (not in place vs in place) was the only significant risk factor of insomnia [OR=10.56, 95%CI: 4.00-27.87]. The prevalence of anxiety and insomnia was high in our study, reflecting the psychological impact of COVID-19 on healthcare workers. The unavailability of PPE in place was a significant risk factor of both anxiety and insomnia.
Assuntos
Humanos , COVID-19 , Distúrbios do Início e da Manutenção do Sono/epidemiologia , Ansiedade/epidemiologia , China/epidemiologia , Prevalência , Estudos Transversais , Pessoal de Saúde , Depressão , Pandemias , SARS-CoV-2RESUMO
OBJECTIVE: To evaluate clinical therapeutic effect of acupuncture at Fengchi (GB 20) and Tianzhu (BL 10) on vertebrobasilar insufficiency (VBI). METHODS: One hundred and sixteen cases of VBI were randomly divided into 2 groups, 58 cases in each group. The treatment group were treated with acupuncture at Fengchi (GB 20) and Tianzhu (BL 10), and the control group with oral administration of Nimodipine. Clinical symptoms, and the average blood flow rates of left vertebral artery (LVA), right vertebral artery (RVA) and basilar artery (BA) detected by transcranial Doppler's method (TCD) before and after treatment were investigated. RESULTS: The total effective rate was 89.66% in the treatment group and 86.21% in the control group. Acupuncture had significantly therapeutic effect in improvement of clinical symptoms and the average blood flow rate of BA, better than Nimodipine. CONCLUSION: Acupuncture at Fengch; (GB 20) and Tianzhu (BL 10) has obvious therapeutic effect on vertebrobasilar insufficiency.
Assuntos
Pontos de Acupuntura , Terapia por Acupuntura , Artéria Basilar , Humanos , Artéria Vertebral , Insuficiência Vertebrobasilar/terapiaRESUMO
OBJECTIVE: To test and verify the transient therapeutic effect of acupuncture at point "Qingchuan" on bronchial asthma. METHODS: Two hundred cases of bronchial asthma at acute attack stage were divided into a trial group of 100 cases treated with acupuncture at point "Qingchuan" and a control group of 100 cases treated with acupuncture at Dingchuan (EX-B1). RESULTS: The total effective rate was 92.60% and the effect occurred within 42-860 seconds after acupuncture in the trial group, and 81.0% and within 114-126 seconds in the control group, respectively, with very significant differences between the two groups (P < 0.01, P < 0.001). CONCLUSION: Acupuncture at point "Qingchuan" can significantly improve asthmatic state in the patient of bronchial asthma with action of rapidly stopping asthma.