Sleep deprivation boosts O2·- levels in the brains of mice as visualized by a Golgi apparatus-targeted ratiometric fluorescence nanosensor.

Sleep deprivation (SD) is highly prevalent in the modern technological world. Emerging evidence shows that sleep deprivation is associated with oxidative stress. At the organelle level, the Golgi apparatus actively participates in the stress response. In this study, to determine whether SD and Golgi apparatus stress are correlated, we rationally designed and fabricated a novel Golgi apparatus-targeted ratiometric nanoprobe called Golgi dots for O2·- detection. This probe exhibits high sensitivity and selectivity in cells and brain slices of sleep-deprived mice. Golgi dots can be readily synthesized by coprecipitation of Golgi-F127, an amphiphilic polymer F127 modified with a Golgi apparatus targeting moiety, caffeic acid (CA), the responsive unit for O2·-, and red emissive carbon nanodots (CDs), which act as the reference signal. The fluorescence emission spectrum of the developed nanoprobe showed an intense peak at 674 nm, accompanied by a shoulder peak at 485 nm. As O2·- was gradually added, the fluorescence at 485 nm continuously increased; in contrast, the emission intensity at 674 nm assigned to the CDs remained constant, resulting in the ratiometric sensing of O2·-. The present ratiometric nanoprobe showed high selectivity for O2·- monitoring due to the specific recognition of O2·- by CA. Moreover, the Golgi dots exhibited good linearity with respect to the O2·- concentration within 5 to 40 µM, and the limit of detection (LOD) was ~ 0.13 µM. Additionally, the Golgi dots showed low cytotoxicity and an ability to target the Golgi apparatus. Inspired by these excellent properties, we then applied the Golgi dots to successfully monitor exogenous and endogenous O2·- levels within the Golgi apparatus. Importantly, with the help of Golgi dots, we determined that SD substantially elevated O2·- levels in the brain.

Determining the geographical origin and cultivation methods of Shanghai special rice using NIR and IRMS.

Songjiang CPB rice (cultivated by a 'combination of planting and breeding') and Chongming NCFP rice (cultivated by using 'no chemical fertilizers and pesticides') are two high quality special rice products developed for Shanghai urban agriculture. Protecting these products from geographical origin mislabeling or cultivation method fraud are very important. To verify the origin of Songjiang and Chongming rice and discriminate their cultivation methods (CPB or N (non) CPB, NCFP or chemical fertilizers and pesticides (CFP)), NIR and IRMS methods combined with chemometrics were developed. Results showed complete separation of Songjiang and Chongming rice from other geographic origins using NIR combined with PLSDA and LVQNN; CPB and NCPB Songjiang rice could be completely identified using NIR or IRMS, while the optimal identification accuracy rate of NCFP from CFP in Chongming rice was 87.5%. It provided a rapid and robust method to identify the origin and cultivation methods of Shanghai special rice.

Occurrence of Microplastics in Fish and Shrimp Feeds.

Plastics with particle sizes of 100 nm to 5 mm are known as microplastics. The contamination of seafood-based feeds by larger microplastics (20 µm to 5 mm) is a growing concern. Here, we analyzed fish and shrimp meals. Microplastics were extracted using density separation methods and characterized using scanning micro Fourier transform infrared spectroscopy (µ-FT-IR). The average microplastic abundance in shrimp meal was 10.7 microplastics·100 g-1. In fish meal, 1.02% of the microplastics were smaller than 1 mm, while most of the microplastics in shrimp meal were 1-5 mm. Eight colors of microplastics were observed; black, red, and orange microplastics have been rarely reported in previous studies. The microplastics found included films, fibers, and fragments, with film-type microplastics being the most common. The main chemical components of fiber-type microplastics were olefins and polyester, while film- and fragment-type microplastics were mainly paraffin and polyethylene. Additional in-depth studies of microplastics in feeds are necessary to provide data support for feed safety assessments.

Isotope chemometrics determines farming methods and geographical origin of vegetables from Yangtze River Delta Region, China.

Shanghai city has encountered possible food fraud regarding the geographical mislabeling of vegetables for economic gain. A combination of δ13C, δ15N, δ2H and δ18O values and partial least squares discrimination analysis and support vector machine (SVM) methods were used for the first time to assess farming methods and determine the origin of vegetables from Shanghai city, Anhui and Zhejiang provinces. The results showed that 65.8% of Shanghai vegetables, 38.2% of Anhui vegetables and 23.6% of Zhejiang vegetables appeared to be grown using green or organic farming methods. The optimal discriminant model was obtained using SVM with a predictive accuracy of 100% for Shanghai vegetables. Zhejiang vegetables had a predictive accuracy of 91.7%, while it was difficult to distinguish Anhui vegetables from Shanghai or Zhejiang vegetables. Therefore, this study provided a useful method to identify vegetable farming methods and discriminate vegetables from Shanghai and Zhejiang.