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Background: Surface-enhanced Raman scattering (SERS) has been deployed in the analysis of food at solid and aqueous states. However, its capability has not been fully explored in headspace profiling. Objective: To develop an innovative SERS method for analyzing headspace volatile compounds in foods. Methods: A volatile-capture device was developed by depositing a film of silver nanoparticles in a vial cap to capture the volatiles released from a model flavor compound (garlic). Results: SERS peaks at 1632, 1400, 1291, 1191, 731, and 577cm-1 were identified in the headspace of the garlic sample, which was representative of an organosulfur compound (diallyl disulfide), and its concentration was determined at 135 ppm, which was comparable to the value determined using GC. Preparation and analysis could be carried out in <10min for the SERS method. The sensitivity of the SERS method (10 ppm), however, was slightly less than that of the GC method (5 pm). Conclusions: The SERS method was able to quantify the concentration of diallyl disulfide in the headspace of a raw garlic ethanolic extract. Compared to GC, the SERS method had a much shorter analysis time and simpler sample preparation procedure than GC when analyzing large numbers of samples. Highlights: The innovative “mirror-in-a-cap” substrate was simpler and faster than other reported SERS substrates used for this purpose. Additionally, SERS has much better portability and the potential for real-time monitoring of changes in the garlic headspace concentration during manufacturing and processing. [ABSTRACT FROM AUTHOR]

In the industrial internet of things (IIoT), because thousands of pieces of hardware, instruments, and various controllers are involved, the core problem is the sensors. Detection using sensors is the bottom line of the IIoT, directly affecting the detection accuracy and control indicators of the IIoT system. However, when a large number of realtime data generated by IIoT devices are transferred to cloud computing centers, large-scale data will inevitably bring computing load, which will affect the computing speed of cloud computing centers and increase the computing load of cloud computing data centers. These factors directly lead to instability and delay in sensor data collected in real time in the IIoT. In this paper, a sensor outlier detection algorithm based on edge calculation is proposed. Firstly, focusing on the problem of the large amount of data in terminal equipment of the IIoT, the edge technology method of data compression is used to optimize the compression of sensor data, and different thresholds are set according to different industrial process requirements, so as to ensure the real-time aspect and authenticity of the data. Then, using the K-means clustering algorithm, the compressed test data sets are analyzed and the abnormal sensor detection values and labels are obtained. Finally, the effectiveness of such an approach is evaluated through a sample case study involving a temperature control system. [ABSTRACT FROM AUTHOR]

Introduction: The environment of the operating room (OR) is closely related to the postoperative complications of patients, and it is necessary to study, to what extent, the stringent management of the OR can reduce postoperative complications. Methodology: 426 patients who underwent surgery between January 2016 and December 2017 were selected from two class-100 laminar flow ORs of equivalent area, and were divided into an experimental group and a control group. Results: The experimental group had significantly lower total air-borne bacterial count in the OR than the control group 10 minutes before surgery (6.21 ± 4.14 vs. 11.58 ± 5.36 CFU/cm³), 10 minutes (15.67 ± 6.21 vs. 20.83 ± 5.78 CFU/cm³), 30 minutes (27.34 ± 8.18 vs. 39.56 ± 7.86 CFU/cm³) and 60 minutes (43.62 ± 7.66 vs. 51.63 ± 8.43 CFU/cm³) into surgery, and at the end of surgery (57.34 ± 7.67 vs. 69.33 ± 9.41 CFU/cm³) (all p < 0.05). The incidence rates of increased body temperature and leukocyte count 3 days post-surgery, and the duration of antibiotic therapy and hospital stay were significantly reduced in the experimental group compared to the control group (all p < 0.05). Furthermore, the total number of pathogens in the incision at 2 hours into surgery was also significantly lower in the experimental group than in the control group (p < 0.05). Conclusion: Stringent application of the infection control pathway is an efficacious measure for improving the air cleanliness of the neurosurgery OR, decreasing the incidence rates of postoperative complications and infection, as well as controlling pathogen transmission. [ABSTRACT FROM AUTHOR]

We developed an innovative approach that couples headspace solid-phase microextraction (SPME) with surface-enhanced Raman spectroscopy (SERS) to detect a volatile pesticide (i.e., fonofos) in a liquid complex matrix (i.e., apple juice). A gold nanoparticles-coated fiber was fabricated by reducing gold(III) on a chemically etched stainless steel wire to extract pesticide, using SPME. The fabricated fibers were then tested by a headspace-SPME method and a dip-SPME method, followed by SERS detection of fonofos in water and apple juice samples. Using the headspace-SPME method, we can detect as low as 5 ppb of fonofos in water and apple juice, compared with the dip-SPME method, which cannot detect lower than 10 ppb in water and 50 ppb in apple juice. This study demonstrated the potential capability of the headspace-SPME-SERS method for rapid (within 30 min) and sensitive detection of volatile and vaporizable compounds in complex matrices. The developed method could be a potential alternative approach to the gas chromatography method. Future work is needed to optimize the fiber by minimizing signal variation, and it should be tested in a variety of targeted compounds and matrices. [ABSTRACT FROM AUTHOR]

Surface enhanced Raman scattering (SERS) detection using a handheld Raman spectrometer and a bench-top Raman spectrometer was systemically evaluated and compared in this study. Silver dendrites were used as the SERS substrate, and two pesticides, maneb and pyrrolidine dithiocarbamate-ammonium salt (PDCA) were used as the analytes. Capacity and performance were evaluated based on spectral resolution, signal variation, quantitative capacity, sensitivity, flexibility and intelligence for SERS detection. The results showed that the handheld Raman spectrometer had better data consistency, more accurate quantification capacity, as well as the capacity of on-site and intelligence for qualitative and semi-quantitative analysis. On the other hand, the bench-top Raman spectrometer showed about 10 times higher sensitivity, as well as flexibility for optimization of the SERS measurements under different parameters such as laser power output, collective time, and objective magnification. The study on the optimization of SERS measurements on a bench-top spectrometer provides a useful guide for designing a handheld Raman spectrometer, specifically for SERS detection. This evaluation can advance the application of a handheld Raman spectrometer for the on-site measurement of trace amounts of pesticides or other chemicals. [ABSTRACT FROM AUTHOR]

A search for regulators of estrogen receptor α (ERα) expression has yielded a set of microRNAs (miRNAs) for which expression is specifically elevated in ERα-negative breast cancer. Here we show distinct expression of a panel of miRNAs between ERα-positive and ERα-negative breast cancer cell lines and primary tumors. Of the elevated miRNAs in ERα-negative cells, miR-221 and miR-222 directly interact with the 3′-untranslated region of ERα. Ectopic expression of miR-221 and miR-222 in MCF-7 and T47D cells resulted in a decrease in expression of ERα protein but not mRNA, whereas knockdown of miR-221 and miR-222 partially restored ERα in ERα protein-negative/mRNA-positive cells. Notably, miR-221- and/or miR-222-transfected MCF-7 and T47D cells became resistant to tamoxifen compared with vector-treated cells. Furthermore, knockdown of miR-221 and/or miR-222 sensitized MDA-MB-468 cells to tamoxifen-induced cell growth arrest and apoptosis. These findings indicate that miR-221 and miR-222 play a significant role in the regulation of ERα expression at the protein level and could be potential targets for restoring ERα expression and responding to antiestrogen therapy in a subset of breast cancers. [ABSTRACT FROM AUTHOR]