RESUMO
In this work, an effective strategy for the large-scale fabrication of highly porous CuO/Cu2O/Cu/carbon (P-Cu-C) has been established. Cu-cross-linked aerogels were first continuously prepared using a continuous flow mode to form uniform beads, which were transformed into P-Cu-C with a subsequent pyrolysis process. Various pyrolysis temperatures were used to form a series of P-Cu-C including P-Cu-C-250, P-Cu-C-200, P-Cu-C-350, and P-Cu-C-450 to investigate suitable pyrolysis conversion processes. The obtained P-Cu-C series were utilized as anodes of lithium-ion batteries, in which P-Cu-C-250 exhibited a higher reversible gravimetric capacity, excellent rate capability, and superior cycle stability. The enhanced behavior of P-Cu-C-250 was benefitted from the synergistic interaction between uniformly dispersed CuO, Cu2O, Cu nanoparticles, and highly graphitized carbon with a large surface area and highly porous structure. More importantly, the preparation of P-Cu-C-250 could be scaled up by taking advantage of the continuous flow synthesis mode, which may provide pilot- or industrial-scale applications. The large-scale fabrication proposed here may give a universal method to fabricate highly porous metal oxide-carbon anode materials for electrochemical energy conversion and storage applications. Porous CuO/Cu2O/Cu/carbon derived from Cu-crosslinked aerogels was used as Li-ion battery anode materials, exhibiting a high reversible areal capacity, large gravimetric capacity, superior cycling performance, and excellent rate capacity. A continuous preparation method is established to ensure the product scaled up.
RESUMO
OBJECTIVES: The aim of this study was to develop an ultrasound-based nomogram to improve the diagnostic accuracy of the identification of malignant thyroid nodules. METHODS: A total of 1675 histologically proven thyroid nodules (1169 benign, 506 malignant) were included in this study. The nodules were grouped into the training dataset (n = 700), internal validation dataset (n = 479), or external validation dataset (n = 496). The grayscale ultrasound features included the nodule size, shape, aspect ratio, echogenicity, margins, and calcification pattern. We applied least absolute shrinkage and selection operator (lasso) regression to select the strongest features for the nomogram. Nomogram discrimination (area under the receiver operating characteristic curve, AUC) and calibration were assessed. The nomogram was subjected to bootstrapping validation (1000 bootstrap resamples) to calculate a mean AUC and 95% confidence interval (CI). RESULTS: The nomogram showed good discrimination in the training dataset, with an AUC of 0.936 (95% CI: 0.918-0.953) and good calibration. Application of the nomogram to the internal validation dataset also resulted in good discrimination (AUC: 0.935; 95% CI, 0.915-0.954) and good calibration. The model tested in an external validation dataset demonstrated a lower AUC of 0.782 (95% CI: 0.776-0.789). CONCLUSIONS: This ultrasound-based nomogram can be used to quantify the probability of malignant thyroid nodules. KEY POINTS: ⢠Ultrasound examination is helpful in the differential diagnosis of malignant and benign thyroid nodules. ⢠However, ultrasound accuracy relies heavily on examiner experience. ⢠A less subjective diagnostic model is desired, and the developed nomogram for thyroid nodules showed good discrimination and good calibration.
Assuntos
Nomogramas , Nódulo da Glândula Tireoide/diagnóstico por imagem , Ultrassonografia/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Reprodutibilidade dos Testes , Estudos Retrospectivos , Glândula Tireoide/diagnóstico por imagem , Glândula Tireoide/patologia , Nódulo da Glândula Tireoide/patologia , Adulto JovemRESUMO
The structural and functional characterizations of titanium nitride (TiN) advanced ceramic microsprings (CMSs), with a coil diameter of several micrometers and synthesized by chemical vapor deposition (CVD) were investigated by microscopy techniques. The CMSs were sufficiently mechanically elastic for extension to more than 1.3 times their original size, and they spontaneously contracted to their original state on releasing the tension. To explore their application to a microdevice, a method of manufacturing TiN-CMS microcircuit elements was developed. The I-V plots of the elements indicated that the CMSs were as conductive as metals.
Assuntos
Cerâmica/química , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Sistemas Microeletromecânicos/instrumentação , Nanotecnologia/instrumentação , Titânio/química , Módulo de Elasticidade , Condutividade Elétrica , Desenho de Equipamento , Análise de Falha de Equipamento , Teste de Materiais , Conformação Molecular , Tamanho da Partícula , Estresse Mecânico , Propriedades de Superfície , Resistência à TraçãoRESUMO
Developing an additive to effectively regulate the perovskite crystallization kinetics for the optimized optoelectronic properties of perovskite film plays a vital role in obtaining high efficiency and stable perovskite solar cells (PSCs). Herein, a new additive is designed and directly synthesized in perovskite precursor solution by utilizing an addition reaction between but-3-yn-1-amine hydrochloride (BAH) and formamidinium iodide. It is found that its product may control the intermediate precursor phase for regulating perovskite nucleation, leading to advantageous 2D perovskite to induce growth of perovskite along the preferred [001] orientation with not only released lattice strain but also strong interaction with perovskite to passivate its surface defects. By taking advantage of the above synergistic effects, the optimized PSC delivers an efficiency of 25.19% and a high open-circuit voltage (VOC) of 1.22 V. Additionally, the devices demonstrate good stability, remaining over 90% of their initial efficiencies under ambient atmosphere conditions for 60 days, high temperature of 85 °C for 200 h, or maximum power point tracking for 500 h.
RESUMO
Judicious tailoring of the interface between the SnO2 electron-transport layer and the perovskite buried surface plays a pivotal role in obtaining highly efficient and stable perovskite solar cells (PSCs). Herein, a DL-carnitine hydrochloride (DL) is incorporated into the perovskite/SnO2 interface to suppress the defect-states density. A DL-dimer is obtained at the interface by an intermolecular esterification reaction. For the SnO2 film, the Cl- in the DL-dimer can passivate oxygen vacancies (VO ) through electrostatic coupling, while the N in the DL-dimer can coordinate with the Sn4+ to passivate Sn-related defects. For the perovskite film, the DL-dimer can passivate FA+ defects via hydrogen bonding and Pb-related defects more efficiently than the DL monomer. Upon DL-dimer modification, the interfacial defects are effectively passivated and the quality of the resultant perovskite film is improved. As a result, the DL-treated device achieves a gratifying open-circuit voltage (VOC ) of 1.20 V and a champion power conversion efficiency (PCE) of 25.24%, which is a record value among all the reported FACsPbI3 PSCs to date. In addition, the unencapsulated devices exhibit a charming stability, sustaining 99.20% and 90.00% of their initial PCEs after aging in air for 1200 h and continuously operating at the maximum power point tracking for 500 h, respectively.
RESUMO
BACKGROUND: Demyelination is similar with malignancy in clinical symptoms. Magnetic resonance imaging (MRI) is an important auxiliary examination in the diagnosis of demyelinating diseases and malignancy. Since MRI and symptoms can be difficult to distinguish demyelination from malignancy, other auxiliary examinations, such as demyelinating disease-specific antibodies, play an important role in distinguishing them. Previous studies have reported demyelinating disease-specific antibodies in patients with malignancy. What's more, it is more difficult to confirm the diagnosis when the malignant tumor co-occurs with demyelinating diseases, which has never been reported in previous studies. We report the diagnosis of myelin oligodendrocyte glycoprotein antibody associated encephalomyelitis (MOG-EM) in a patient who had astrocytoma for several years. CASE PRESENTATION: Patient's concerns and diagnoses: our case report records a 49-year-old woman with astrocytoma for more than 4 years, who recently developed the symptoms of MOG-EM, including dizziness, vomiting, and vision loss. This astrocytoma patient was diagnosed with MOG-EM according to comprehensive evidence, including MRI, visual evoked potential (VEP), serum myelin oligodendrocyte glycoprotein antibody (MOG-IgG), and therapeutic effect. Interventions and outcomes: this patient was diagnosed with astrocytoma by surgical biopsy 4 years earlier. This patient has been treated with tumor resection, postoperative radiation treatment and chemotherapy. After treatment, the patient was left with right limb weakness while other symptoms were improved. Recently, the intravenous steroid agent was used to treat this patient after being diagnosed with MOG-EM. Dizziness, vomiting, and vision loss have gone into remission. This patient did not relapse in 7 months after discharge. This patient is still being followed up at the outpatient clinic. And the patient will next be treated with azathioprine. CONCLUSIONS: In previous studies, polyclonal antibody has been found in cancer patients, such as aquaporin-4 and MOG-IgG in astrocytoma patients. But the case of our study finds that astrocytoma can coexist with MOG-EM. Therefore, MOG-EM should not be excluded easily in astrocytoma patients when the relative antibody of encephalomyelitis is positive. What's more, it reminds us that the pathogenesis of MOG-EM might be related to astrocytoma.
Assuntos
Astrocitoma , Doenças Desmielinizantes , Encefalomielite , Aquaporina 4 , Astrocitoma/diagnóstico , Astrocitoma/terapia , Autoanticorpos , Azatioprina , Tontura , Potenciais Evocados Visuais , Humanos , Imunoglobulina G , Glicoproteína Mielina-Oligodendrócito , Recidiva Local de Neoplasia , Esteroides , VômitoRESUMO
The redistribution method plays an important role in addressing the issue of organosilicon by-products in the direct synthesis of dichlorodimethylsilane, and the redistribution mechanism is still a topic of debate. The redistribution mechanism by the ZSM-5(3 T)@γ-Al2O3 core-shell catalyst and post-modified AlCl3/ZSM-5(3 T)@γ-Al2O3 catalyst was technically performed using the Density functional theory (DFT) at the level of B3LYP/6-311 + + G(3df,2pd). The results show that no. 1 active site of ZSM-5(3 T)@γ-Al2O3 core-shell structure has a significant effect on the activity of the catalyst. Indicating that the active center involved in the reaction is H provided by the Al-O-H bond, which is an obvious catalytic active center of Bronsted acid. Furthermore, the post-modified AlCl3/ZSM-5(3T)@γ-Al2O3 catalyst is in more favor of redistribution reaction comparing with the ZSM-5(3 T)@γ-Al2O3 core-shell catalyst. It ascribes to the robust Lewis site of aluminum chloride favorable modification. The redistribution synthesis mechanism of dichlorodimethylsilane on the ZSM-5(3 T)@γ-Al2O3 core-shell catalyst and post-modified AlCl3/ZSM-5(3 T)@γ-Al2O3 catalyst had been investigated by using the Density functional theory (DFT) method at the level of B3LYP/6-311 + + G(3df,2pd). The former active center was Bronsted acidic center, while the latter one was Lewis acidic center, ascribing to the Lewis site of aluminum chloride favorable modification. The catalytic activity of the post-synthesis AlCl3/ZSM-5(3 T)@γ-Al2O3 catalyst completely was consistent with experimental results.
RESUMO
A novel glucose biosensor was constructed by using ferrocene-carbonyl-beta-cyclodextrin (FcCD) inclusive complex as electron-transfer mediator and carbon nanotubes (CNTs) as electron-transfer promoter. FcCD inclusive complex and glucose oxidase (GOx) were covalently bonded to CNTs by poly-l-lysine (PLL) to fabricate a glucose biosensor. The electrocatalytic oxidation of glucose at the biosensor occurred at low potential below 200 mV, avoiding the interference of the main interfering substances in real samples containing a 5-times higher concentration of l-cysteine, ascorbic acid, and uric acid. The biosensor showed fast response for glucose. A broad linear range of glucose concentration from 1.0 x 10(-5) to 2.90 x 10(-3) M was obtained and the detection limit was 2.2 x 10(-6) M.
Assuntos
Técnicas Biossensoriais/métodos , Compostos Ferrosos/química , Glucose Oxidase/química , Glucose/análise , Nanotubos de Carbono/química , beta-Ciclodextrinas/química , Técnicas Eletroquímicas/métodos , Glucose Oxidase/metabolismo , Metalocenos , Oxirredução , Polilisina/químicaRESUMO
In this experiment, the conjugation reaction between gluten and maltose via Maillard reaction under dry-heated condition was studied. The process conditions for the preparation of protein-maltose conjugates with optimum solubility were optimized by using Box-Behnken model. The conjugation reaction and the structure changes of the protein-maltose conjugates were confirmed by infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results showed that the process conditions for the preparation of protein-maltose conjugates with optimum solubility were as follows: temperature 50.72°C, time 1.92 days, and gluten/maltose (W/W) 267.36%. The infrared spectroscopy showed that the structure of the modified protein had a very obvious change, including the decrease in ß-fold and ß-turn and the increase in α-helix at a certain degree. But the conjugation reaction has little effect on the irregular coiled structure. The scanning electron microscopy showed that the microstructure of gluten is small grainy, but gluten-maltose conjugate looks sheet with bigger volume.
RESUMO
BACKGROUND: A key challenge in thyroid carcinoma is preoperatively diagnosing malignant thyroid nodules. The purpose of this study was to compare the classification performance of linear and nonlinear machine-learning algorithms for the evaluation of thyroid nodules using pathological reports as reference standard. METHODS: Ethical approval was obtained for this retrospective analysis, and the informed consent requirement was waived. A total of 1179 thyroid nodules (training cohort, n = 700; validation cohort, n = 479) were confirmed by pathological reports or fine-needle aspiration (FNA) biopsy. The following ultrasonography (US) featu res were measured for each nodule: size (maximum diameter), margins, shape, aspect ratio, capsule, hypoechoic halo, composition, echogenicity, calcification pattern, vascularity, and cervical lymph node status. We analyzed five nonlinear and three linear machine-learning algorithms. The diagnostic performance of each algorithm was compared by using the area under the curve (AUC) of the receiver operating characteristic curve. We repeated this process 1000 times to obtain the mean AUC and 95% confidence interval (CI). RESULTS: Overall, nonlinear machine-learning algorithms demonstrated similar AUCs compared with linear algorithms. The Random Forest and Kernel Support Vector Machines algorithms achieved slightly greater AUCs in the validation cohort (0.954, 95% CI: 0.939-0.969; 0.954 95%CI: 0.939-0.969, respectively) than other algorithms. CONCLUSIONS: Overall, nonlinear machine-learning algorithms share similar performance compared with linear algorithms for the evaluation the malignancy risk of thyroid nodules.
Assuntos
Neoplasias da Glândula Tireoide/patologia , Nódulo da Glândula Tireoide/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Biópsia por Agulha Fina/métodos , Calcinose/patologia , Métodos Epidemiológicos , Feminino , Humanos , Linfonodos/patologia , Aprendizado de Máquina , Masculino , Pessoa de Meia-Idade , Pescoço/patologia , Neoplasias da Glândula Tireoide/classificação , Nódulo da Glândula Tireoide/classificação , Ultrassonografia , Adulto JovemRESUMO
OBJECTIVES: To explore the feasibility of preoperative prediction of vascular invasion (VI) in breast cancer patients using nomogram based on multiparametric MRI and pathological reports. METHODS: We retrospectively collected 200 patients with confirmed breast cancer between January 2016 and January 2018. All patients underwent MRI examinations before the surgery. VI was identified by postoperative pathology. The 200 patients were randomly divided into training (n = 100) and validation datasets (n = 100) at a ratio of 1:1. Least absolute shrinkage and selection operator (LASSO) regression was used to select predictors most associated with VI of breast cancer. A nomogram was constructed to calculate the area under the curve (AUC) of receiver operating characteristics, sensitivity, specificity, accuracy, positive prediction value (PPV) and negative prediction value (NPV). We bootstrapped the data for 2000 times without setting the random seed to obtain corrected results. RESULTS: VI was observed in 79 patients (39.5%). LASSO selected 10 predictors associated with VI. In the training dataset, the AUC for nomogram was 0.94 (95% confidence interval [CI]: 0.89-0.99, the sensitivity was 78.9% (95%CI: 72.4%-89.1%), the specificity was 95.3% (95%CI: 89.1%-100.0%), the accuracy was 86.0% (95%CI: 82.0%-92.0%), the PPV was 95.7% (95%CI: 90.0%-100.0%), and the NPV was 77.4% (95%CI: 67.8%-87.0%). In the validation dataset, the AUC for nomogram was 0.89 (95%CI: 0.83-0.95), the sensitivity was 70.3% (95%CI: 60.7%-79.2%), the specificity was 88.9% (95%CI: 80.0%-97.1%), the accuracy was 77.0% (95%CI: 70.0%-83.0%), the PPV was 91.8% (95%CI: 85.3%-98.0%), and the NPV was 62.7% (95%CI: 51.7%-74.0%). The nomogram calibration curve shows good agreement between the predicted probability and the actual probability. CONCLUSION: The proposed nomogram could be used to predict VI in breast cancer patients, which was helpful for clinical decision-making.
Assuntos
Neoplasias da Mama/irrigação sanguínea , Adulto , Idoso , Área Sob a Curva , Neoplasias da Mama/patologia , Estudos de Viabilidade , Feminino , Humanos , Angiografia por Ressonância Magnética , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Invasividade Neoplásica , Nomogramas , Cuidados Pré-Operatórios/métodos , Probabilidade , Curva ROC , Estudos Retrospectivos , Sensibilidade e Especificidade , Neoplasias Vasculares/patologiaRESUMO
The bilayer of Con A/HRP through the biospecific affinity of concanavalin A (Con A) and glycoprotein horseradish peroxidase (HRP) was prepared on the surface of an Au electrode modified by the precursor film consisted of poly(allylamine hydrochloride) poly(sodium-p-styrene-sulfonate). Atomic force microscopy and electrochemical impedance spectroscopy were adopted to monitor the uniform layer-by-layer assembly of the Con A/HRP bilayers. The amperometric measurement was based on the inhibition of reduced thiols and performed in the presence of the electron mediator hydroquinone in 0.2M phosphate buffer of pH 6.5 at an applied potential of -0.15 V versus Ag/AgCl. Under the optimal conditions, the biosensor presented a linear response for cysteine from 0.1 to 23.5 microM, with a detection limit of 0.02 microM. The biosensor demonstrated high stability and repeatability. A series of reduced thiols were detected by this inhibition biosensor and oxidized thiols showed no effect on the current response of the biosensor.
Assuntos
Técnicas Biossensoriais/instrumentação , Concanavalina A/química , Peroxidase do Rábano Silvestre/química , Compostos de Sulfidrila/análise , Técnicas Biossensoriais/métodos , Calibragem , Eletrodos , Oxirredução , Reprodutibilidade dos TestesRESUMO
Most of the risk models for predicting contrast-induced acute kidney injury (CI-AKI) are available for postcontrast exposure prediction, thus have limited values in practice. We aimed to develop a novel nomogram based on preprocedural features for early prediction of CI-AKI in patients after coronary angiography (CAG) or percutaneous coronary intervention (PCI). A total of 245 patients were retrospectively reviewed from January 2015 to January 2017. Least absolute shrinkage and selection operator (Lasso) regression model was applied to select most strong predictors for CI-AKI. The CI-AKI risk score was calculated for each patient as a linear combination of selected predictors that were weighted by their respective coefficients. The discrimination of nomogram was assessed by C-statistic. The occurrence of CI-AKI was 13.9% (34 out of 245). We identified ten predictors including sex, diabetes mellitus, lactate dehydrogenase level, C-reactive protein, years since drinking, chronic kidney disease (CKD), stage of CKD, stroke, acute myocardial infarction, and systolic blood pressure. The CI-AKI prediction nomogram obtained good discrimination (C-statistic, 0.718, 95%CI: 0.637-0.800, p = 7.23 × 10-5). The cutoff value of CI-AKI risk score was -1.953. Accordingly, the novel nomogram we developed is a simple and accurate tool for preprocedural prediction of CI-AKI in patients undergoing CAG or PCI.
RESUMO
A carbon coil was evaluated for use as a micro-solenoid in a small magnetic device. A single carbon coil was lifted out of the aggregate using a tungsten fine probe in a focused ion beam (FIB) system and was wired to two small electrodes in the specimen holder of a transmission electron microscope (TEM). A direct current was supplied to the single carbon coil. A micro/nano-magnetic field generated from the coil was directly observed by electron holography. A computer simulation of electron holography was also done to quantitatively analyze the magnetic field. Details on the FIB technique, the electron holographic observation and the simulation are described.
RESUMO
The carbon nanocoils with various kinds of conformations were prepared by the catalytic pyrolysis of acetylene using the Ni metal catalyst supported on molecular Sieves which was prepared using Fe-containing kaolin as the raw material. There are four kinds of carbon nanocoils conformations produced by this catalyst. The influences of reaction temperature and gas conditions on the conformations of the nanocoils were investigated and the reasons of forming nano-size coils were discussed by comparison with pure Ni metal catalyst.
Assuntos
Carbono/química , Ferro , Níquel , Catálise , Microscopia Eletrônica de Varredura , Modelos Moleculares , Conformação Molecular , Nanoestruturas/química , TermodinâmicaRESUMO
Carbon nanocoils were prepared by the chemical vapor deposition process of the catalytic pyrolysis of acetylene at 700-800 degrees C with various catalysts. Twisting or coiling-formed carbon nanocoils with changing coiling-chirality and zigzag-formed carbon nanofibers were obtained with SUS 304, WS2, Pt-Pd, TiN, and Ni as the catalysts. Their morphologies and microstructures were examined in detail, and then the changing mechanism of the coiling-chirality was discussed. No apparent difference in the microstructure between the part of a nanocoil with changing coiling-chirality and the part of a zigzag nanofiber with changing zigzag-chirality, or between a bulk right-clockwise coil and a bulk left-clockwise coil was observed. It was supposed that changing coiling-chirality was mainly caused by the gradual or successive change in chemical composition on the thin layers present on the surface of catalyst grains during the chemical vapor deposition process.
Assuntos
Cristalização/métodos , Temperatura Alta , Teste de Materiais/métodos , Nanotecnologia/métodos , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestrutura , Catálise , Substâncias Macromoleculares , Conformação Molecular , EstereoisomerismoRESUMO
A novel cobalt-tetraphenylporphyrin/reduced graphene oxide (CoTPP/RGO) nanocomposite was prepared by a π-π stacking interaction and characterized by ultraviolet-visible absorption spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). The CoTPP/RGO nanocomposite exhibited high electrocatalytic activity both for oxidation and reduction of H2O2. The current response was linear to H2O2 concentration with the concentration range from 1.0×10(-7) to 2.4×10(-3)molL(-1) (R=0.998) at the reductive potential of -0.20V and from 1.0×10(-7) to 4.6×10(-4)molL(-1) (R=0.996) at the oxidative potential of +0.50V. The H2O2 biosensor showed good anti-interfering ability towards oxidative interferences at the oxidative potential of +0.50V and good anti-interfering ability towards reductive interferences at the reductive potential of -0.20V.
Assuntos
Técnicas Biossensoriais , Cobalto/química , Grafite/química , Peróxido de Hidrogênio/análise , Nanocompostos/química , Porfirinas/química , Espectroscopia Dielétrica , Técnicas Eletroquímicas , Eletrodos , Oxirredução , Óxidos/químicaRESUMO
An amperometric horseradish peroxidase (HRP) biosensor based on multilayer films containing carbon nanotubes (CNTs) and HRP was developed. With the pH regulation of the dispersion solution of CNTs, the sensitivity of the HRP multilayer film biosensor is tunable by the control of the dissociation of CNTs. The successful formation of multilayers was confirmed by UV-visible spectroscopy. The features of multilayers were characterized by SEM and electrochemical impedance spectrum (EIS). The performance of the HRP biosensor is reported for the amperometric detection of phenols. The biosensor presented a linear response for catechol from 9.1 × 10(-8) - 6.45 × 10(-5) mol/L, with a sensitivity of 0.00554 A · L/mol and a detection limit of 8.5 × 10(-8) mol/L. The study can provide a feasible simple approach for developing a new sensitivity tunable method for CNTs-based biosensors.
Assuntos
Técnicas Biossensoriais/métodos , Peroxidase do Rábano Silvestre/metabolismo , Nanotubos de Carbono/química , Fenóis/análise , Ácidos Carboxílicos/química , Eletroquímica , Eletrodos , Estudos de Viabilidade , Peroxidase do Rábano Silvestre/química , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Oxirredução , Fenóis/químicaRESUMO
In this paper, a polydopamine (PDA) film is electropolymerized on the surface of bilayer lipid membrane (BLM) which is immobilized with horseradish peroxidase (HRP). The coverage of the PDA film on HRP/BLM electrode is monitored by electrochemical impedance spectroscopy (EIS). The electrocatalytic reduction of H(2)O(2) at the PDA/HRP/BLM electrode is studied by means of cyclic voltammetry (CV). The biosensor has a fast response to H(2)O(2) of less than 5s and an excellent linear relationship is obtained in the concentration range from 2.5×10(-7) to 3.1×10(-3) molL(-1), with a detection limit of 1.0×10(-7) molL(-1) (S/N=3). The response current of BLM/HRP/PDA biosensor retains 84% of its original response after being stored in 0.1 molL(-1) pH 7.0 PBS at 4°C for 3 weeks. The selectivity, repeatability, and storage stability of PDA/HRP/BLM biosensor are greatly enhanced by the coverage of polydopamine film on BLM.
Assuntos
Técnicas Biossensoriais/métodos , Peróxido de Hidrogênio/análise , Bicamadas Lipídicas/química , Dopamina/análogos & derivados , Técnicas Eletroquímicas , Eletrodos , Limite de Detecção , PolimerizaçãoRESUMO
OBJECTIVE: To assess the effectiveness of 23-valent penumococcal polysaccharide vaccine (PenV23) and Split-Virus influenza vaccine (InfV-B) for preventing upper respiratory diseases in the aging population. METHODS: 151 people aged > or =60 years who inoculated the PenV23 and InfV-B vaccines at clinics during 2005 as trial group, and 188 people aged > or =65 years didn't administered as control guoup from some comminity. On base line survey, both guoups were followed up two years after vaccination about incidence, hospitalization rate, treatment and direct medical cost. RESULTS: The vaccine of PenV23 and InfV-B vaccination in upper respiratory tract infection was 60% [(odds ratio OR) = 0.35, 95% CI (0.153-0.794)] and the difference between the 2 groups was significant (P = 0.009). The people had recevied both vaccines, the mean duration of hospitalization in vaccinated vs unvaccinated control peple was 20.00 days: 24.19 days (t = 5.82, P < 0.001). Benefit-cost ratio was 4.03, and the net benefit was Yen 177994.86. CONCLUSION: Incidence of influenza-like illness for the elderly people in the community decreased by administered PenV23 ahd InfV-B vaccine. This vaccines had high cost-benefits.