Optimization and evaluation of multi-bed adsorbent tube method in collection of volatile organic compounds

The feasibility of using adsorbent tubes to collect volatile organic compounds (VOCs) has been demonstrated since the 1990's and standardized as Compendium Method TO-17 by the U.S. Environmental Protection Agency (U.S EPA). This paper investigates sampling and analytical variables on concentrations of 57 ozone (O-3) precursors (C-2-C-12 aliphatic and aromatic VOCs) specified for the Photochemical Assessment Monitoring Station (PAMS). Laboratory and field tests examined multi-bed adsorbent tubes containing a sorbate combination of Tenax TA, Carbograph 1 TD, and Carboxen 1003. Analyte stabilities were influenced by both collection tube temperature and ambient O-3 concentrations. Analytes degraded during storage, while blank levels were elevated by passive adsorption. Adsorbent tube storage under cold temperatures (- 10 degrees C) in a preservation container filled with solid silica gel and anhydrous calcium sulfate (CaSO4) ensured sample integrity. A high efficiency (> 99%) O-3 scrubber (i.e., copper coil tube filled with saturated potassium iodide [KM removed O-3 (i.e., < 200 ppbv) from the air stream with a sampling capacity of 30 h. Water vapor scrubbers interfered with VOC measurements. The optimal thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) desorption time of 8 min was found at 330 degrees C. Good linearity (R-2 > 0.995) was achieved for individual analyte calibrations (with the exception of acetylene) for mixing ratios of 0.08-1.96 ppbv. The method detection limits (MDLs) were below 0.055 ppbv for a 3 L sample volume. Replicate analyses showed relative standard deviations (RSDs) of < 10%, with the majority of the analytes within < 5%

Comprehensive Evaluation of Fruit Quality of Actinidia arguta Based on Principal Component Analysis and Cluster Analysis

In order to scientifically evaluate the fruit quality of different Actinidia arguta varieties and establish the quality evaluation system, 10 Actinidia arguta varieties were used as experimental materials, and the indexes of fruit appearance quality and nutritional quality were measured and compared under edible conditions. The fruit quality of Actinidia arguta was comprehensively evaluated by correlation analysis, principal component analysis and cluster analysis. The results showed that the quality indexes of different varieties of Actinidia arguta were different and correlated. The difference of the content of Vitamin C was largest, and the coefficient of variation was 53.08%. The difference of fruit color brightness (L* value) was the smallest, and the coefficient of variation was 6.04%. By principal component analysis, 18 quality indicators were simplified into 6 principal components, and the cumulative variance contribution rate was 90.571%, which could reflect most of the information of the original quality indexes. The comprehensive scores of quality indexes of 10 Actinidia arguta varieties were ranked as ‘Longcheng No.2’, ‘Kuilü’, ‘Jialü’, ‘Wanlü’, ‘Tianxinbao’, ‘Lübao’, ‘Xinlü’, ‘Cuiyu’, ‘Fenglü’ and ‘Pingllü’. According to cluster analysis, 10 Actinidia arguta varieties were divided into five categories, among which ‘Longcheng No.2’ and ‘Kuilü’ in the first category had better comprehensive quality traits. The study provided a reference for the variety breeding, planting, extension and rational processing and utilization of Actinidia arguta

EMG-Centered Multisensory Based Technologies for Pattern Recognition in Rehabilitation: State of the Art and Challenges

In the field of rehabilitation, the electromyography (EMG) signal plays an important role in interpreting patients’ intentions and physical conditions. Nevertheless, utilizing merely the EMG signal suffers from difficulty in recognizing slight body movements, and the detection accuracy is strongly influenced by environmental factors. To address the above issues, multisensory integration-based EMG pattern recognition (PR) techniques have been developed in recent years, and fruitful results have been demonstrated in diverse rehabilitation scenarios, such as achieving high locomotion detection and prosthesis control accuracy. Owing to the importance and rapid development of the EMG centered multisensory fusion technologies in rehabilitation, this paper reviews both theories and applications in this emerging field. The principle of EMG signal generation and the current pattern recognition process are explained in detail, including signal preprocessing, feature extraction, classification algorithms, etc. Mechanisms of collaborations between two important multisensory fusion strategies (kinetic and kinematics) and EMG information are thoroughly explained; corresponding applications are studied, and the pros and cons are discussed. Finally, the main challenges in EMG centered multisensory pattern recognition are discussed, and a future research direction of this area is prospected

Co-synthesis of CuO-ZnO nanoflowers by low voltage liquid plasma discharge with brass electrode

Transition metal oxides CuO-ZnO nano-flowers have been simultaneously synthesized by the low voltage liquid plasma discharge method using brass cathode. The effects of discharge statue (normal and abnormal glow discharge) on the nanostructures were investigated. It was found that a lower discharge voltage 52 V in the normal glow discharge period is beneficial to produce homogeneous nano-flower structures while a higher voltage tend to result in inhomogeneous products including larger particles. The obtained products were characterized by SEM, XRD, high-resolution TEM, Raman and XPS. Moreover, the nano-flowers exhibit a favorable electrocatalytic activity of glucose oxidation.This research was funded by the Chinese Natural Science Foundation (Grant number: 21504025 and 51305230)

Strained carbon steel as a highly efficient catalyst for seawater electrolysis

In response to the global energy crisis, water splitting has become one of the most efficient methods to produce hydrogen as an excellent substitute for fossil fuels. The diffusion coefficient of hydrogen and its interaction with iron have granted carbon steel (CS) the susceptible nature to hydrogen, and therefore CS is considered a promising electrocatalyst in the hydrogen evolution reaction. Compared to many traditional alkaline electrolytes, simulated seawater exhibits reasonable performance that facilitates an effective hydrogen evolution reaction. In the electrolysis of simulated seawater, the lowest overpotential of strained CS samples (-391.08 mV) is comparable to that of Pt plate electrodes (-377.31 mV). This is the result of the plane strain introduced to CS samples by a hydraulic press and indentation, which help to facilitate mass transport through diffusion for hydrogen evolution. The susceptibility of CS is verified by the formation of nanoscale hydrogen blisters that form in the proximity of grain boundaries. These blisters are the result of hydrogen gas pressure that is built up by the absorbed atomic hydrogen. These hydrogen atoms are believed to accumulate along the CS {1 1 0} planes adjacent to grain boundaries. CS has so far not been studied for the catalysis of water splitting. In this study, CS is used as an electrocatalyst for the first time as a cost-effective method for the utilization of seawater that further contributes to the promotion of green energy production

Power analysis of transcriptome-wide association study: Implications for practical protocol choice.

The transcriptome-wide association study (TWAS) has emerged as one of several promising techniques for integrating multi-scale 'omics' data into traditional genome-wide association studies (GWAS). Unlike GWAS, which associates phenotypic variance directly with genetic variants, TWAS uses a reference dataset to train a predictive model for gene expressions, which allows it to associate phenotype with variants through the mediating effect of expressions. Although effective, this core innovation of TWAS is poorly understood, since the predictive accuracy of the genotype-expression model is generally low and further bounded by expression heritability. This raises the question: to what degree does the accuracy of the expression model affect the power of TWAS? Furthermore, would replacing predictions with actual, experimentally determined expressions improve power? To answer these questions, we compared the power of GWAS, TWAS, and a hypothetical protocol utilizing real expression data. We derived non-centrality parameters (NCPs) for linear mixed models (LMMs) to enable closed-form calculations of statistical power that do not rely on specific protocol implementations. We examined two representative scenarios: causality (genotype contributes to phenotype through expression) and pleiotropy (genotype contributes directly to both phenotype and expression), and also tested the effects of various properties including expression heritability. Our analysis reveals two main outcomes: (1) Under pleiotropy, the use of predicted expressions in TWAS is superior to actual expressions. This explains why TWAS can function with weak expression models, and shows that TWAS remains relevant even when real expressions are available. (2) GWAS outperforms TWAS when expression heritability is below a threshold of 0.04 under causality, or 0.06 under pleiotropy. Analysis of existing publications suggests that TWAS has been misapplied in place of GWAS, in situations where expression heritability is low

Relationship between glycated hemoglobin levels and three-month outcomes in acute ischemic stroke patients with or without diabetes: a prospective Korean cohort study

Abstract Objective In patients experiencing acute ischemic stroke, there is ongoing debate surrounding the connection between chronic hyperglycemic status and their initial clinical outcomes. Our objective was to examine the connection between glycated hemoglobin (HbA1c) levels and adverse clinical outcomes at both 3-months adverse clinical outcomes in individuals with acute ischemic stroke (AIS) with and without diabetes. Methods The present prospective cohort study involved 896 AIS patients without diabetes and 628 with diabetes treated at a South Korean hospital from January 2010 to December 2016. The target independent variable is HbA1c. The outcome variable is a modified Rankin scale score ≥ 3. A binary logistic regression model was applied to assess the connection between HbA1c levels and 3-month poor clinical outcomes in AIS patients with and without diabetes. Additionally, a generalized additive model and smoothed curve fitting were utilized to explore potential nonlinear associations between HbA1c levels and 3-month adverse clinical outcomes in AIS patients with and without diabetes. Results The binary logistic regression model could not identify any statistically significant connection between HbA1c and 3-month adverse clinical outcomes in AIS patients, both those with and without diabetes, after correcting for various factors. However, a nonlinear relationship emerged between HbA1c and 3-month adverse clinical outcomes in AIS patients with diabetes. The inflection point for HbA1c was determined to be 6.1%. For HbA1c values ≤ 6.1%, an inverse association was observed between HbA1c and 3-month adverse clinical outcomes in diabetic AIS patients, and each 1% increase in HbA1c in AIS patients with DM was associated with an 87% reduction in 3-month adverse clinical outcomes (OR = 0.13, 95% CI: 0.02–0.81). Conversely, when HbA1c exceeded 6.1%, a positive association between HbA1c and 3-month adverse clinical outcomes became apparent in diabetic AIS patients, and each 1% increase in HbA1c in AIS patients with DM was associated with a 23% increase in 3-month adverse clinical outcomes (OR = 1.23, 95%CI: 1.03–1.47). However, it’s important to note that no significant linear or nonlinear relationships were observed between HbA1c levels and 3-month adverse clinical outcomes in AIS patients without diabetes. Conclusion Our findings suggest a nonlinear connection and threshold effect between HbA1c and 3-month adverse clinical outcomes in AIS patients with diabetes. AIS patients with diabetes had a lower risk of 3-month adverse clinical outcomes when their HbA1c control was close to 6.1%. Our findings may aid treatment decision-making and potentially guide interventions to optimize glycemic control in AIS patients

Flexible Au micro-array electrode with atomic-scale Au thin film for enhanced ethanol oxidation reaction

The catalysis of Au thin film could be improved by fabrication of array structures in large area. In this work, nanoimprint lithography has been developed to fabricate flexible Au micro-array (MA) electrodes with ∼ 100% coverage. Advanced electron microscopy characterisations have directly visualised the atomic-scale three-dimensional (3D) nanostructures with a maximum depth of 6 atomic layers. In-situ observation unveils the crystal growth in the form of twinning. High double layer capacitance brings about large number of active sites on the Au thin film and has a logarithmic relationship with mesh grade. Electrochemistry testing shows that the Au MAs perform much better ethanol oxidation reaction than the planar sample; MAs with higher mesh grade have a greater active site utilisation ratio (ASUR), which is important to build electrochemical double layer for efficient charge transfer. Further improvement on ASUR is expected for greater electrocatalytic performance and potential application in direct ethanol fuel cell.[Figure not available: see fulltext.].Ministry of Education (MOE)This research was supported by the MOE AcRF Tier 1 grant M4011528. The XRD and FEG-TEM characterisations were performed at Facility for Analysis, Characterisation, Testing and Simulation (FACTS) Lab; the FEG-SEM/FIB characterisations were carried out at Microelectronics Reliability and Characterisation (MRC) Lab

Preparation and Physicochemical Properties of Biochar from the Pyrolysis of Pruning Waste of Typical Fruit Tree in North China

Routine maintenance of fruit trees generates a substantial quantity of pruning waste each year. This waste is potential feedstock for producing energy, materials, and other products. The feasibility of making biochar from the waste via pyrolysis was evaluated. The effects of seven tree species, different pruning sites, and temperature on the pyrolysis process, and the physicochemical properties of the biochar were studied. Pyrolysis of different tree species at 500 °C yielded 27.5 to 33.3% biochar, with a high calorific value (approximately 30 MJ/kg), low ash content (approximately 4%), and capturing up to 60% of the carbon element present. Simultaneously, when the temperature was increased from 400 to 700 °C, the yield of biochar decreased from 35.8% to 24.3%, but the properties improved with the higher heating value rising from 29.2 to 31.3 MJ/kg and the iodine value from 234 to 252 mg/g. The biochar has a good pore structure with a specific surface area of 237 m2/g, total pore volume of 0.175 cm3/g, and average pore size of 2.96 nm. In general, biochar from the pyrolysis of fruitwood pruning waste generated here could be an ideal feedstock to produce high-value-added products, such as solid fuels, activated carbon, and electrode materials