Seesaw Precarity: Journaling Anxious Hope on a Chinese University Campus During Covid-19.

In this article, we examine the Covid-19 experiences of a group of Chinese university students studying in the city of Guangzhou. We draw on journal entries that Chinese students submitted to the Pandemic Journaling Project between March and May 2022, along with follow-up responses in July and December 2022, to argue that these students spent most of their undergraduate years living in a state of "seesaw precarity." We define seesaw precarity as a protracted period during which many Chinese were unable to predict from one day to the next whether they would be free to engage in the quotidian activities of everyday life. We trace student reactions and adaptations as they struggled to attend class, buy food, and see friends and family in the midst of unpredictable swings between openness and closedness. The seesaw nature of restrictions spurred considerable anxiety among the students we followed, but also produced an optimistic mindset we refer to as "anxious hope." Participants accepted the necessity of Covid controls and felt it was incumbent upon them as individuals to adjust to this reality. They saw themselves as responsible for actively cultivating a positive mindset. Our findings suggest that the promotion of emotional self-care and anxious hope during the pandemic may have supported the viability of long-term controls as well as the acceptability of their sudden abandonment, while muting the possibility of resistance.

Environmental Factors Influencing Phyllosphere Bacterial Communities in Giant Pandas' Staple Food Bamboos.

The giant panda has developed a series of evolutionary strategies to adapt to a bamboo diet. The abundance and diversity of the phyllosphere microbiome change dramatically depending on the season, host species, location, etc., which may, in turn, affect the growth and health of host plants. However, few studies have investigated the factors that influence phyllosphere bacteria in bamboo, a staple food source of the giant panda. Amplicon sequencing of the 16S rRNA gene was used to explore the abundance and diversity of phyllosphere bacteria in three bamboo species (Arundinaria spanostachya, Yushania lineolate, and Fargesia ferax) over different seasons (spring vs. autumn), elevation, distance from water, etc., in Liziping National Nature Reserve (Liziping NR), China. And whole-genome shotgun sequencing uncovered the differences in biological functions (KEGG and Carbohydrate-Active enzymes functions) of A. spanostachya phyllosphere bacteria between spring and autumn. The results showed that the abundance and diversity of F. ferax phyllosphere bacteria were greater than that of the other two bamboo species in both seasons. And three kinds of bamboo phyllosphere bacteria in autumn were significantly higher than in spring. The season was a more important factor than host bamboo species in determining the community structure of phyllosphere bacteria based on the (un)weighted UniFrac distance matrix. The composition, diversity, and community structure of phyllosphere bacteria in bamboo were primarily affected by the season, species, altitude, tree layer, and shrub layer. Different bacterial communities perform different functions in different bamboo species, and long-term low temperatures may shape more varied and complex KEGG and Carbohydrate-Active enzymes functions in spring. Our study presented a deeper understanding of factors influencing the bacterial community in the bamboo phyllosphere. These integrated results offer an original insight into bamboo, which can provide a reference for the restoration and management of giant panda bamboo food resources in the Xiaoxiangling mountains.

A disposable electrochemical sensor for simultaneous determination of norepinephrine and serotonin in rat cerebrospinal fluid based on MWNTs-ZnO/chitosan composites modified screen-printed electrode.

A new electrochemical sensor for simultaneous determination of norepinephrine (NE) and serotonin (5-HT) was fabricated. The electrochemical behavior of NE and 5-HT were investigated using CV and SWV at the MWNTs-ZnO/chitosan composites modified screen-printed electrode (MWNTs-ZnO/chitosan SPE). The results showed that the current responses of NE and 5-HT greatly enhanced due to the high catalytic activity of composites. The peak potentials of NE and 5-HT were separated at about 90mV and 280mV, respectively. The peak currents of NE and 5-HT were linearly dependent on their concentrations in the range of 0.5-30µM and 0.05-1µM, with the limit of detection of 0.2µM and 0.01µM, respectively. The modified electrode can be stored stably for at least 3 month at 4°C in a refrigerator. Furthermore, the modified electrode was successfully applied to detect the level of NE and 5-HT in rat cerebrospinal fluid (CSF) with excellent selectivity and sensitivity.

Protective effects of aloe-emodin on scopolamine-induced memory impairment in mice and H2O2-induced cytotoxicity in PC12 cells.

Aloe-emodin (AE) is one of the most important active components of Rheum officinale Baill. The present study aimed to investigate that AE could attenuate scopolamine-induced cognitive deficits via inhibiting acetylcholinesterase (AChE) activity and modulating oxidative stress. Kunming (KM) mice were received intraperitoneal injection of scopolamine (2 mg/kg) to induce cognitive impairment. Learning and memory performance were assessed in the Morris water maze (MWM). After behavioral testing, the mice were sacrificed and their hippocampi were removed for biochemical assays (superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA), AChE and acetylcholine (ACh)). In vitro, we also performed the AChE activity assay and H2O2-induced PC12 cells toxicity assay. After 2 h exposure to 200 µM H2O2 in PC12 cells, the cytotoxicity were evaluated by cell viability (MTT), nitric oxide (NO)/lactate dehydrogenase (LDH) release and intracellular reactive oxygen species (ROS) production. Our results confirmed that AE showed significant improvement in cognitive deficit in scopolamine-induced amnesia animal model. Besides, it increased SOD, GPx activities and ACh content, while decreased the level of MDA and AChE activity in AE treated mice. In addition, AE was found to inhibit AChE activity (IC50 = 18.37 µg/ml) in a dose-dependent manner. Furthermore, preincubation of PC12 cells with AE could prevent cytotoxicity induced by H2O2 and reduce significantly extracellular release of NO, LDH and intracellular accumulation of ROS. The study indicated that AE could have neuroprotective effects against Alzheimer's disease (AD) via inhibiting the activity of AChE and modulating oxidative stress.

A high-throughput method for the simultaneous determination of multiple mycotoxins in human and laboratory animal biological fluids and tissues by PLE and HPLC-MS/MS.

A high-throughput method for the determination of 28 mycotoxins involving pressurised liquid extraction (PLE) coupled with liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) has been optimised and validated for determination in various biological fluids and tissues of human and laboratory animals. High-throughput analysis was achieved using PLE pre-treatment and without the need for any cleanup. The extraction solvent was acetonitrile/water/acetic acid (80/19/1, v/v/v). The static extraction time was 5min. The extraction pressure and temperature were 1500psi and 140°C, respectively. The flush volume was 60%. The limits of detection, which were defined as CCα, varied from 0.01µg/kg (µg/L) to 0.69µg/kg (µg/L). The recoveries of spiked samples from 0.20µg/kg (µg/L) to 2µg/kg (µg/L) ranged from 71% to 100.5% with relative standard deviations of less than 17.5%, except FB1 and FB2 recoveries, which were lower than 60%. The method was successfully applied in real samples, and the data indicate that this technique is a useful analytical method for the determination of mycotoxins from humans and animals. To the best of our knowledge, this method is the first for the large-scale testing of multi-class mycotoxins in all types of biological fluids and tissues that uses PLE and HPLC-MS/MS.