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Severe acute respiratory syndrome coronavirus 2 breakthrough infection in highly vaccinated populations raises study on the effectiveness for inactivated vaccine, including effectiveness of the vaccine dose, the continuance of effectiveness, the effectiveness against severe/critical coronavirus disease 2019 and against secondary attacks. A population of 10 870 close contacts were investigated in a Delta variant's epidemic. The effectiveness of vaccination was estimated in a test-negative case-control study. In addition, serum was used to detect neutralizing antibodies, to explore their correlation to effectiveness. The vaccine effectiveness (VE) values were estimated for populations aged 12 years or older. The overall adjusted VE was 56.2% and a two-dose vaccine was more effective than a one-dose vaccine (56.7% vs. 43.8%). In addition, the population that got the second dose vaccine within 2 months showed higher VE than the population vaccinated for longer than 2 months (61.5% vs. 52.3%). Among the population who vaccinated 2 doses or within 2 months, a higher level of neutralizing antibodies was observed. For infected cases, vaccinated populations showed lower rates of transmission (2.63% vs. 4.36%). Further, those vaccinated cases, who were not found causing transmission, had a higher level of antibodies. The study provided a full view of the effectiveness of inactivated vaccines in a real-world setting. The time-related VE against infection and lower transmission of breakthrough vaccinated cases were observed, which may indicate that a necessity of a booster vaccine to maintain the effectiveness and high level of neutralizing antibody.
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Vacunas contra la COVID-19 , COVID-19 , Humanos , Anticuerpos Neutralizantes , COVID-19/prevención & control , Estudios de Casos y Controles , SARS-CoV-2 , Anticuerpos AntiviralesRESUMEN
The COVID-19 pandemic has had a profound impact on the mental health of healthcare workers (HCWs). We aimed to identify the factors associated with depression among HCWs during the pandemic. We conducted literature search using eight electronic databases up to July 27 2022. Observational studies with more than 200 participants investigating correlates of depression in HCWs after COVID-19 outbreak were included. We used fixed- and random-effects models to pool odds ratios (ORs) across studies, and Cochran's chi-squared test and I 2 statistics to assess study heterogeneity. Publication bias was evaluated by funnel plots. Thirty-five studies involving 44,362 HCWs met the inclusion criteria. Female (OR=1.50, 95% CI [1.23,1.84]), single (OR=1.36, 95% CI [1.21,1.54]), nurse (OR=1.69, 95% CI [1.28,2.25]), history of mental diseases (OR=2.53, 95% CI [1.78,3.58]), frontline (OR=1.79, 95% CI [1.38,2.32]), health anxiety due to COVID-19 (OR=1.88, 95% CI [1.29,2.76]), working in isolation wards (OR=1.98, 95% CI [1.38,2.84]), and insufficient personal protective equipment (OR=1.49, 95% CI [1.33,1.67]) were associated with increased risk of depression. Instead, HCWs with a positive professional prospect (OR=0.34, 95% CI [0.24,0.49]) were less likely to be depressed. This meta-analysis provides up-to-date evidence on the factors linked to depression among HCWs during the COVID-19 pandemic. Given the persistent threats posed by COVID-19, early screening is crucial for the intervention and prevention of depression in HCWs.
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BACKGROUND: The relationship between serum apolipoprotein A1 (APOA1) and atrial fibrillation (AF) is not known. Therefore, we sought to investigate the associations between APOA1 and AF in the Chinese population. METHODS: This case-control study included 950 patients with AF (29-83 years old, 50.42% male) who were hospitalized consecutively in China between January 2019 and September 2021. Controls with sinus rhythm and without AF were matched (1:1) to cases by sex and age. Pearson correlation analysis was performed to investigate the correlation between APOA1 and blood lipid profiles. Multivariate regression models were used to explore the association between APOA1 and AF. The receiver operator characteristic (ROC) curve was constructed to examine the performance of APOA1. RESULTS: Multivariate regression analysis showed that low serum APOA1 in men and women with AF was significantly associated with AF (OR = 0.261, 95% CI: 0.162-0.422, P < 0.001). Pearson correlation analysis indicated that serum APOA1 was positively correlated with total cholesterol (TC) (r = 0.456, p < 0.001), low-density lipoprotein cholesterol (LDL-C) (r = 0.825, p < 0.001), high-density lipoprotein cholesterol (HDL-C) (r = 0.238, p < 0.001), and apolipoprotein B (APOB) (r = 0.083, p = 0.011). ROC curve analysis showed that APOA1 levels of 1.105 g/L and 1.205 g/L were the optimal cut-off values for predicting AF in males and females, respectively. CONCLUSION: Low APOA1 in male and female patients is significantly associated with AF in the Chinese population of non-statin users. APOA1 may be a potential biomarker for AF and contribute to the pathological progression of AF along with low blood lipid profiles. Potential mechanisms remain to be further explored.
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Fibrilación Atrial , Femenino , Humanos , Masculino , Adulto , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Apolipoproteína A-I , Estudios de Casos y Controles , Pueblos del Este de Asia , HDL-ColesterolRESUMEN
BACKGROUND: Hypoalbuminemia is linked to the emergence of cardiovascular events. However, there is an unclear association between serum albumin (ALB) and gender in paroxysmal AF patients. This retrospective study aimed to explore the association between ALB levels and paroxysmal AF by gender in a Chinese population. METHODS: This study included patients with paroxysmal AF who were hospitalized consecutively in China from January 2019 to September 2021. Controls with sinus rhythm and without paroxysmal AF were matched (2:1) to cases by gender and age. Pearson correlation analysis was used to study the correlation between ALB and blood lipid profiles, multivariate regression models were performed to investigate the association between ALB and paroxysmal AF. RESULTS: There were 305 patients with paroxysmal AF and 610 patients with controls included in this study. Low ALB in male with AF patients were significantly associated with paroxysmal AF (OR = 0.889, 95% CI 0.832-0.950). ALB was positively correlated with triglyceride (TG) (r = 0.212, p < 0.001), total cholesterol (TC) (r = 0.381, p = 0.002), low-density lipoprotein cholesterol (LDL-C) (r = 0.263, p < 0.001), and high-density lipoprotein cholesterol (HDL-C) (r = 0.329, p < 0.001). CONCLUSION: Low ALB in male patients is significantly associated with paroxysmal AF in a Chinese population. Monitoring for hypoalbuminemia in men might help reduce the incidence of paroxysmal AF.
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Fibrilación Atrial , Hipoalbuminemia , Estudios de Casos y Controles , HDL-Colesterol , Humanos , Masculino , Estudios Retrospectivos , Albúmina SéricaRESUMEN
BACKGROUND The association between patients' serum uric acid (SUA) levels and sex in atrial fibrillation (AF) remains controversial. This retrospective study from a single center in China aimed to evaluate the association between sex and SUA levels in 950 patients with AF. MATERIAL AND METHODS We retrospectively analyzed clinical information of 1913 consecutive hospitalized patients (male/female: 949/964, 68.26±11.02 years). The sample of 950 patients with AF served as the AF group and 963 age- and sex-matched patients without AF with sinus rhythm served as controls. The uricase method was used to determine SUA levels. The analysis of variance, t test, and chi-squared test were performed to analyze clinical baseline data. Pearson correlation analysis was performed to identify interrelationships and multivariate regression analysis was performed to determine the independent risk factor for AF. RESULTS SUA levels in the AF group were significantly higher in both sexes (P<0.05), especially for permanent AF. In patients with AF, SUA levels were positively correlated with serum creatinine (r=0.235, P<0.05) and prealbumin (r=0.129, P<0.05) and were negatively correlated with high-density lipoprotein cholesterol (r=-0.207, P<0.05) and apolipoprotein A1 (r=-0.167, P<0.05). SUA was independently associated with AF after adjusting for confounding factors (OR=1.244, 95% CI: 1.133-1.365, P<0.05). CONCLUSIONS In both sexes, increased SUA was significantly associated with AF. These findings supported the importance of monitoring SUA levels in patients with AF and other cardiac diseases.
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Fibrilación Atrial , Femenino , Humanos , Masculino , Análisis de Regresión , Estudios Retrospectivos , Factores de Riesgo , Ácido ÚricoRESUMEN
The authors requested several labels to be corrected: 1. Lp (a), mg/L should be Lp (a), mg/dL: 2. ALT/AST should be AST/ALT. Reference: Xia Zhong, Huachen Jiao, Dongsheng Zhao, Jing Teng: Serum Uric Acid Levels in Relation to Atrial Fibrillation: A Case-Control Study. Med Sci Monit, 2022; 28: e934007. DOI: 10.12659/MSM.934007.
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BACKGROUND Although serum uric acid (SUA) levels have been reported to be associated with atrial fibrillation (AF), the specific associations remain unclear. The purpose of this study was to investigate the potential relationship of serum uric acid levels to atrial fibrillation. MATERIAL AND METHODS We retrospectively analyzed clinical data of 970 consecutive hospitalized patients (M/F, 519/451; age, 64.78±13.49 years). The study included 478 patients with AF, and 492 age-matched patients with sinus rhythm and no history of arrhythmia as a control group. The t test, ANOVA, chi-squared test, or Fisher exact test were performed to analyze clinical baseline data. RESULTS Compared with the control group, patients with AF exhibited higher SUA levels (5.66±1.90 vs 5.35±1.55 mg/dL, P=0.006), especially women (P<0.001). Pearson correlation analysis showed SUA was influenced by A/G, PAB, and APOA1 in patients with AF. Logistic regression analysis showed SUA was associated with AF (total: OR=1.002, 95% CI: 1.000-1.003; women: OR=1.005, 95% CI: 1.003-1.007). After adjustment for clinical related factors for AF, SUA was still associated with AF (total: OR=1.004, 95% CI: 1.002-1.006; women: OR=1.005, 95% CI: 1.002-1.009). Also, elevated SUA was positively correlated with A/G and PAB and negatively correlated with APOA1. There were no significant differences in SUA levels in AF subtypes and complications. CONCLUSIONS Elevated SUA levels were associated with AF, but the independent association was significant only in women. Elevated SUA may promote other AF-related factors and participate in the pathological process of AF.
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Fibrilación Atrial/sangre , Ácido Úrico/sangre , Biomarcadores/sangre , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de RiesgoRESUMEN
BACKGROUND Variations of heart rate variability (HRV) before paroxysmal atrial fibrillation (PAF) onset are still controversial. We aimed to observe the autonomic tone variations before PAF onset based on HRV analysis. MATERIAL AND METHODS We prospectively investigated 24-h Holter recordings of 60 patients with PAF (M/F: 34/26) and 40 healthy people in sinus rhythm (M/F: 18/12). According to clinical information and Poincare scatter plot, 60 PAF patients were divided into sympathetic group (n=20) and vagus group (n=40). Time domain and frequency domain parameters of HRV were respectively measured before PAF episodes in 3 subgroups. Five time periods were studied using the ANOVA. RESULTS No significant variations were observed for the HRV parameters during 60 minutes preceding PAF in sympathetic group. A significant and linear change in SDNN, RMSSD, PNN50, HF and LF/HF during 60 minutes preceding PAF onset in vagus group. Compared with controls, RMSSD, LF and HF were significantly longer in patients with PAF during 60 minutes before PAF. Comparing sympathetic group and vagus group, we observed the same pattern of autonomic variations with a progressive decrease in LF and HF. A progressive decrease in PNN50 and LF/HF of sympathetic group and a significant increase in PNN50 and LF/HF of vagus group were also observed. CONCLUSIONS Patients with PAF mediated by different autonomic nerves have HRV variations, especially vagus PAF, there was a progressive increase with vagal tone during 60 minutes before PAF onset. The findings may help clinicians better intervene in PAF.
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Fibrilación Atrial/fisiopatología , Ritmo Circadiano/fisiología , Electrocardiografía Ambulatoria/métodos , Frecuencia Cardíaca/fisiología , Nervio Vago/fisiopatología , Anciano , Anciano de 80 o más Años , Fibrilación Atrial/diagnóstico , Ecocardiografía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de TiempoRESUMEN
BACKGROUND Depression is a common disease worldwide, with about 280 million people having depression. The unique facial features of depression provide a basis for automatic recognition of depression with deep convolutional neural networks. MATERIAL AND METHODS In this study, we developed a depression recognition method based on facial images and a deep convolutional neural network. Based on 2-dimensional images, this method quantified the binary classification problem and distinguished patients with depression from healthy participants. Network training consisted of 2 steps: (1) 1020 pictures of depressed patients and 1100 pictures of healthy participants were used and divided into a training set, test set, and validation set at the ratio of 7: 2: 1; and (2) fully connected convolutional neural network (FCN), visual geometry group 11 (VGG11), visual geometry group 19 (VGG19), deep residual network 50 (ResNet50), and Inception version 3 convolutional neural network models were trained. RESULTS The FCN model achieved an accuracy of 98.23% and a precision of 98.11%. The Vgg11 model achieved an accuracy of 94.40% and a precision of 96.15%. The Vgg19 model achieved an accuracy of 97.35% and a precision of 98.13%. The ResNet50 model achieved an accuracy of 94.99% and a precision of 98.03%. The Inception version 3 model achieved an accuracy of 97.10% and a precision of 96.20%. CONCLUSIONS The results show that deep convolution neural networks can support the rapid, accurate, and automatic identification of depression.
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Depresión , Redes Neurales de la Computación , Depresión/diagnóstico por imagen , HumanosRESUMEN
BACKGROUND It remains unclear whether there is a sex difference in the association between serum albumin (ALB) and atrial fibrillation (AF). This retrospective case-control study from a single center in China aimed to determine the association between serum ALB levels and AF by sex in 950 patients. MATERIAL AND METHODS Data of 950 AF patients and 963 age- and sex-matched non-AF patients with sinus rhythm were collected and analyzed retrospectively. Clinical baseline data were analyzed using the t test or Mann-Whitney U test, analysis of variance (ANOVA), and chi-square test. The interrelationships were determined by Pearson correlation analysis, and multivariate logistic regression analysis was performed to adjust for covariables. RESULTS ALB levels of AF patients were significantly lower in both sexes (P<0.05), especially paroxysmal AF. ALB was positively correlated with total cholesterol (TC) (r=0.359, P<0.05), low-density lipoprotein cholesterol (LDL-C) (r=0.283, P<0.05), and serum apolipoprotein A1 (APOA1) (r=0.429, P<0.05) and was negatively correlated with serum creatinine (SCr) (r=0.129, P<0.05) in patients with AF. We found an independent negative association between ALB levels and AF in men after adjusting for confounding factors (OR=0.889, 95% CI: 0.845-0.934, P<0.05). CONCLUSIONS In patients at a single center in China, low serum ALB levels in male patients were significantly associated with AF. These findings support those from previous studies in other populations and highlight the importance of monitoring and treating the cause of hypoalbuminemia in cardiac patients.
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Fibrilación Atrial , Estudios de Casos y Controles , China , LDL-Colesterol , Femenino , Humanos , Masculino , Estudios Retrospectivos , Factores de Riesgo , Albúmina SéricaRESUMEN
BACKGROUND The serum apolipoprotein B/A1 ratio (APOB/APOA1) has been shown to predict cardiovascular events, whereas the effect of the APOB/APOA1 ratio on atrial fibrillation (AF) is less known. We investigated the association between the APOB/APOA1 ratio and AF by sex in 920 patients from China. MATERIAL AND METHODS We reviewed clinical data on 1840 hospitalized patients, including 920 patients with AF (male/female: 460/460, age: 68.62±10.36 years) and 920 age- and sex-matched patients without AF with sinus rhythm in China between January 2019 and September 2021. Pearson correlation analysis was performed to investigate the correlation between APOB/APOA1 ratio and AF-related metabolic factors. Logistic regression analysis was used to determine the odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS Low serum APOB/APOA1 ratios in male and female patients were significantly associated with AF after adjusting for confounding factors (OR 0.159, 95% CI 0.058-0.432, P<0.05). Serum APOB/APOA1 ratio was positively correlated with triglyceride (TG) (r=0.146, P<0.05) and total cholesterol (TC) (r=0.227, P<0.05) and was negatively correlated with albumin (ALB) (r=-0.128, P<0.05) and prealbumin (PAB) (r=-0.107, P<0.05). There was no significant difference of APOB/APOA1 ratio in different subtypes, complications, and statin use in patients with AF (P>0.05). CONCLUSIONS A low serum APOB/APOA1 ratio in male and female patients from China was significantly related to AF. This finding implies that a low serum APOB/APOA1 ratio may be associated with the causes of AF. Further studies are needed to determine causalities.
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Fibrilación Atrial , Anciano , Apolipoproteína A-I , Apolipoproteínas B , Estudios de Casos y Controles , China , Femenino , Humanos , Masculino , Persona de Mediana Edad , TriglicéridosRESUMEN
In indoor positioning, signal fluctuation is one of the main factors affecting positioning accuracy. To solve this problem, a new method based on an integration of the empirical mode decomposition threshold smoothing method (EMDT) and improved weighted K nearest neighbor (WKNN), named EMDT-WKNN, is proposed in this paper. First, the nonlinear and non-stationary received signal strength indication (RSSI) sequences are constructed. Secondly, intrinsic mode functions (IMF) selection criteria based on energy analysis method and fluctuation coefficients is proposed. Thirdly, the EMDT method is employed to smooth the RSSI fluctuation. Finally, to further avoid the influence of RSSI fluctuation on the positioning accuracy, the deviated matching points are removed, and more precise combined weights are constructed by combining the geometric distance of the matching points and the Euclidean distance of fingerprints in the positioning method-WKNN. The experimental results show that, on an underground parking dataset, the positioning accuracy based on EMDT-WKNN can reach 1.73 m in the 75th percentile positioning error, which is 27.6% better than 2.39 m of the original RSSI positioning method.
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To improve the user's positioning accuracy of a Wi-Fi fingerprint-based positioning algorithm, this study proposes a graph optimization model based on the framework of g2o that fuses a Wi-Fi fingerprint and Bluetooth Low Energy (BLE) ranging technologies. In our model, the improvement in positioning can be formulated as a nonlinear least-squares optimization problem that a graph can represent. The graph regards users as nodes and our self-designed error functions between users as edges. In the graph, the nodes obtain the initial coordinates through Wi-Fi fingerprint positioning, and all error functions aggregate to a total error function to be solved. To improve the solution effect of the total error function and weaken the influence of measurement error, an information matrix, an edge selection principle, and a Huber kernel function are introduced. The Levenberg-Marquardt (LM) algorithm is used to solve the total error function and the affine transformation estimation is used for the drifting solution. Through experiments, the influence of the threshold in the Huber kernel function is explored, the relationship between the number of nodes in the graph and the optimization effect is analyzed, and the impact of the distribution of nodes is researched. The experimental results show improvements in the positioning accuracy of four common Wi-Fi fingerprint-matching algorithms: KNN, WKNN, GK, and Stg.
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The installed wind energy generation capacity has been increasing dramatically all over the world. However, most wind turbines are installed in hostile environments, where regular operation needs to be ensured by effective fault tolerant control methods. An adaptive observer-based fault tolerant control scheme is proposed in this article to address the sensor and actuator faults that usually occur on the core subsystems of wind turbines. The fast adaptive fault estimation (FAFE) algorithm is adopted in the adaptive observers to accurately and rapidly located the faults. Based on the states and faults estimated by the adaptive observers, the state feedback fault tolerant controllers are designed to stabilize the system and compensate for the faults. The gain matrices of the controllers are calculated by the pole placement method. Simulation results illustrate that the proposed fault tolerant control scheme with the FAFE algorithm stabilizes the faulty system effectively and performs better than the baseline on the benchmark model of wind turbines.
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This study aimed to determine how gender composition affects the group creative process. Participants were recruited into dyads with different gender compositions (female-male dyad, F-M; female-female, F-F; male-male, and M-M) to solve two problems. One problem demanded creativity alternative use task (AUT) and the other did not object characteristic task. Functional near-infrared spectroscopy (fNIRS)-based hyperscanning was used to record interpersonal neural responses. Results demonstrated no significant difference in creative performance among the three types of dyads. However, the F-F dyad showed higher levels of cooperative behaviour (i.e. the index of convergence) and collective flexibility than the other dyads. Also, in the fNIRS data, the F-F dyad showed higher interpersonal brain synchronization (IBS) increments in the right posterior parietal cortex during the AUT than the other dyads, which covaried with their creative performance. These findings indicate that while solving a creativity problem together, females are more likely than males to consider others' perspectives. This gender difference might be due to the enhanced IBS increment in the right posterior parietal cortex.
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Conducta Cooperativa , Creatividad , Neuroimagen Funcional , Lóbulo Parietal/fisiología , Solución de Problemas/fisiología , Interacción Social , Espectroscopía Infrarroja Corta , Adulto , Femenino , Humanos , Masculino , Lóbulo Parietal/diagnóstico por imagen , Factores Sexuales , Adulto JovenRESUMEN
Since 1992, China has promoted hepatitis B vaccination. Concurrently, during this period, increasing use of immunoglobulins and nucleoside analogues might have exerted selective pressure on the hepatitis B virus (HBV) S gene, driving mutations in the HBsAg and changed the subtype. Using the National Center for Biotechnology Information database, we obtained gene sequence information for HBV strains from China and analysed changes in HBsAg subtypes and substitution mutations in HBsAg in 5-year intervals over 25 years to identify potential challenges to the prevention and treatment of hepatitis B. Most HBV sequences from China were genotype C (1996/2833, 70.46%) or B (706/2833, 24.92%). During the implementation of hepatitis B vaccination (recombinant hepatitis B vaccine was subgenotype A2 and HBsAg subtype adw2), the proportion of subtypes ayw1 and adw3 in genotype B and ayw2 in genotype C increased over the programme period. The overall mutation rate in HBsAg tended to decrease for genotype B, whereas, for genotype C, the rate increased gradually and then decreased slightly. Moreover, the mutation rate at some HBsAg amino acid sites (such as sG145 of genotype B and sG130 and sK141 of genotype C) is gradually increasing. HBV strains with internal stop codons of HBsAg (e.g., sC69*) and additional N-glycosylation (e.g., sG130N) mutations should be studied extensively to prevent them from becoming dominant circulating strains. The development of HBV vaccines and antiviral immunoglobulins and use of antiviral drugs may require making corresponding changes.
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Genes Virales , Antígenos de Superficie de la Hepatitis B/genética , Virus de la Hepatitis B/genética , Programas de Inmunización , China/epidemiología , Codón de Terminación , Glicosilación , Hepatitis B/prevención & control , Hepatitis B/virología , Vacunas contra Hepatitis B/administración & dosificación , Humanos , Mutación , Tasa de MutaciónRESUMEN
A new electrocatalytic biosensor (MOF-74(Cu) NS-CC) based on the in situ deposition of MOF-74(Cu) nanosheet on carbon cloth via a bottom-up synthetic approach in a glass tube was developed. The electrocatalytic activity of the deposited MOF-74(Cu) NS was demonstrated in the oxidation of glucose to gluconate under alkaline conditions. The results revealed that the proposed method of in situ formation of MOF-74(Cu) NS onto a carbon cloth surface in a multi-layer solution is capable to generate a stable MOF-74(Cu) NS-CC electrode with excellent sensing performance. When the as-synthesized MOF-74(Cu) NS-CC was applied directly as the working electrode for glucose sensing, it showed much higher conductivity and redox activity than MOF-74(Cu) NS-GCE. With the potential applied at 0.55 V (vs. Ag/AgCl), this new electrocatalytic biosensor exhibits an excellent linear relationship between current density and concentration of glucose. Moreover, a wide linear range of detection (1.0 to 1000 µM) was observed. The limit of detection was found to be 0.41 µM (S/N = 3). The response sensitivity is 3.35 mA mM-1 cm-2 when the concentration of glucose is in the range 1-100 µM and 3.81 mA mM-1 cm-2 for the 100-1000 µM concentration range. This study provides a low-cost, easy to prepare, and reproducible methodology for the synthesis of highly redox-active nanomaterials based on the in situ formation of two-dimensional MOF-74(Cu) NS for the development of new electrocatalytic biosensors. Graphical abstract.
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Técnicas Biosensibles/métodos , Glucemia/análisis , Carbono/química , Estructuras Metalorgánicas/química , Nanoestructuras/química , Catálisis , Cobre/química , Técnicas Electroquímicas , Electrodos , Humanos , Límite de Detección , Oxidación-Reducción , Reproducibilidad de los ResultadosRESUMEN
The wind power industry continues to experience rapid growth worldwide. However, the fluctuations in wind speed and direction complicate the wind turbine control process and hinder the integration of wind power into the electrical grid. To maximize wind utilization, we propose to precisely measure the wind in a three-dimensional (3D) space, thus facilitating the process of wind turbine control. Natural wind is regarded as a 3D vector, whose direction and magnitude correspond to the wind's direction and speed. A semi-conical ultrasonic sensor array is proposed to simultaneously measure the wind speed and direction in a 3D space. As the ultrasonic signal transmitted between the sensors is influenced by the wind and environment noise, a Multiple Signal Classification algorithm is adopted to estimate the wind information from the received signal. The estimate's accuracy is evaluated in terms of root mean square error and mean absolute error. The robustness of the proposed method is evaluated by the type A evaluation of standard uncertainty under a varying signal-to-noise ratio. Simulation results validate the accuracy and anti-noise performance of the proposed method, whose estimated wind speed and direction errors converge to zero when the SNR is over 15 dB.
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BACKGROUND: It is well known that plant essential oils have good antimicrobial activity. However, their strong volatility and intense odor limit their application. Mesoporous silica (MCM-41), a non-toxic mesoporous material with excellent loading capability, is a promising delivery system for different types of food ingredients in the food industry. RESULTS: In this study, we first performed component analysis of pepper fragrant essential oil (PFEO) by gas chromatography - mass spectrometry (GC-MS), then the MCM-41 host was prepared, and the essential oil functionalized nanoparticles (EONs) were formed by embedding PFEO into mesoporous silica particles. Further analysis indicated that the particle size and zeta potential of EONs were 717 ± 13.38 nm and - 43.90 ± 0.67 mV, respectively. Transmission electron microscopy (TEM) images showed that EONs had an inerratic morphology and stable structure. The bactericidal activities of PFEO and EONs against Escherichia coli (E. coli), Salmonella enterica (S. enterica), Staphylococcus aureus (S. aureus) and Listeria monocytogenes (L. monocytogenes) were subsequently tested using the twofold dilution method. Results indicated that, after 48 h incubation, minimum bactericidal concentrations (MBC) of EONs used against gram-negative bacteria were decreased to a greater degree than those of PFEO, suggesting that nanoencapsulation by MCM-41 can improve antimicrobial activity. Atomic force microscopy (AFM) observation also confirmed that EONs showed a notable inhibitory effect against E. coli by disrupting cell membrane structure. CONCLUSION: Pepper fragrant essential oil nanoencapsulation could be a very promising organic delivery system in food industry for antimicrobial activity enhancement. © 2019 Society of Chemical Industry.
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Antibacterianos/farmacología , Nanopartículas/química , Aceites Volátiles/química , Aceites Volátiles/farmacología , Aceites de Plantas/química , Aceites de Plantas/farmacología , Antibacterianos/química , Portadores de Fármacos/química , Composición de Medicamentos , Escherichia coli/efectos de los fármacos , Cromatografía de Gases y Espectrometría de Masas , Listeria monocytogenes/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Odorantes/análisis , Dióxido de Silicio/química , Staphylococcus aureus/efectos de los fármacosRESUMEN
The United Network for Organ Sharing recently altered current liver allocation with the goal of decreasing Model for End-Stage Liver Disease (MELD) variance at transplant. Concerns over these and further planned revisions to policy include predicted decrease in total transplants, increased flying and logistical complexity, adverse impact on areas with poor quality health care, and minimal effect on high MELD donor service areas. To address these issues, we describe general approaches to equalize critical transplant metrics among regions and determine how they alter MELD variance at transplant and organ supply to underserved communities. We show an allocation system that increases minimum MELD for local allocation or preferentially directs organs into areas of need decreases MELD variance. Both models have minimal adverse effects on flying and total transplants, and do not disproportionately disadvantage already underserved communities. When combined together, these approaches decrease MELD variance by 28%, more than the recently adopted proposal. These models can be adapted for any measure of variance, can be combined with other proposals, and can be configured to automatically adjust to changes in disease incidence as is occurring with hepatitis C and nonalcoholic fatty liver disease.