A Simple SERS-Based Trace Sensing Platform Enabled by AuNPs-Analyte/AuNPs Double-Decker Structure on Wax-Coated Hydrophobic Surface

In this work, a simple and versatile SERS sensing platform enabled by AuNPs-analyte/AuNPs double-decker structure on wax-coated hydrophobic surface was developed using a portable Raman spectrometer. Wax-coated silicon wafer served as a hydrophobic surface to induce both aggregation and concentration of aqueous phase AuNPs mixed with analyte of interest. After drying, another layer of AuNPs was drop-cast onto the layer of AuNPs-analyte on the substrate to form double-decker structure, thus introducing more “hot spots” to further enhance the Raman signal. To validate the sensing platform, methyl parathion (pesticide), and melamine (a nitrogen-enrich compound illegally added to food products to increase their apparent protein content) were employed as two model compounds for trace sensing demonstration. The as-fabricated sensor showed high reproducibility and sensitivity toward both methyl parathion and melamine detection with the limit of detection at the nanomolar and sub-nanomolar concentration level, respectively. In addition, remarkable recoveries for methyl parathion spiked into lake water samples were obtained, while reasonably good recoveries for melamine spiked into milk samples were achieved. These results demonstrate that the as-developed SERS sensing platform holds great promise in detecting trace amount of hazardous chemicals for food safety and environment protection

Nitrogen use efficiency of rye (Secale cereale) using organic fertilizers

It’s urgent to increase per capita food production to meet the increasing population and its high demand while maintaining environmental stability. Aim to have higher yields as well as reduce harm to the environment, the most difficult problem is how to improve the nutrient use efficiency of plants. Thus using recycling fertilizers is more important in the agriculture practices, it can result in a long-term benefit of plants and environment. In order to explore the impacts of recycling fertilizers on grain yield and on fertilizer nitrogen use efficiency (NUE), an experiment was laid out with the randomized design with 4 replicates of 6 treatments. The objectives were: (1) to test a range of organic fertilizers in arable crop production, especially to find possible differences in nitrogen productivity (2) to find possible differences in nitrogen uptake and in uptake efficiency by rye between variable organic fertilizers and between organic and mineral fertilizers. In the experiment, biogas residual, chemical fertilization, vermicompost, meat and bone meal, sewage sludge compost and unfertilized control were compared. The rates of N application, as kg N/ha varied from one fertilizer to another. This thesis studied impacts on field rye (Secale cereale). There were significant improvements (p < 0.05) in SPAD value, N yield in biomass, total above-ground biomass, and grain yield with the application of the fertilizers, compared with non-fertilized plots. Especially biogas residual, sewage sludge compost and chemical fertilizers were effective. The highest, 33% nitrogen use efficiency was achieved with chemical fertilizer, while sewage sludge compost was the best among organic fertilizers. Recycling fertilizers can produce as high yields of rye as mineral fertilizers, with equal fertilizer nitrogen use efficiency. The critical factor for high yield is the amount of total nitrogen applied, and plant availability of the nitrogen and various organic fertilizers vary in NUE

Body Fat Percentage and Normal-Weight Obesity in the Chinese Population: Development of a Simple Evaluation Indicator Using Anthropometric Measurements

Few studies explore the associations between body fat percentage (BFP) prediction and evaluation indicators for Chinese with normal-weight obesity. We aimed to explore convenient and cost-free BFP evaluation indicators to routinely monitor BFP status in Chinese patients with normal-weight obesity. Participants (N = 164) were divided into three groups according to body mass index (BMI) and BFP: normal-weight lean, normal-weight obese, and overweight and obese. Differences in body composition and circumference were compared to examine the relationship between BFP and circumference, determine a simple evaluation indicator reflecting BFP, and identify cutoff values for normal-weight obesity circumference. Significant differences in body composition and circumference were observed among the three groups. The correlation between thigh/height, hip/height, (hip + waist)/height, and BFP was stronger than that with BMI. The (hip + waist)/height ratio was the indicator most reflective of BFP (95% confidence interval: 3.004&ndash;9.018, p = 0.013), and a ratio above 1.115 (95% confidence interval: 0.936&ndash;0.992, p &lt; 0.001) was predictive of normal-weight obesity. Furthermore, we suggest that the upper value for a normal BMI in Chinese individuals be lowered to 23.4 kg/m2 (95% confidence interval: 0.984&ndash;0.999, p &lt; 0.001). The (hip + waist)/height ratio can be used with body mass index for a more accurate evaluations of BFP abnormalities and health risks