Sleep behaviors predicted sleep disturbances among Chinese health science students: a cross-sectional study.

PURPOSE: Healthy sleep is essential for individuals' physiological and psychological health. Health science students experience a high prevalence of sleep disturbances which may be due to maladaptive behaviors. This study aimed to examine the associations of sleep behaviors including sleep hygiene and bedtime procrastination with the associations of sleep disturbances (e.g., poor sleep quality, insomnia, and short sleep). METHODS: This cross-sectional study included health science students from a medical university in Shanghai, China. Sleep disturbances included poor sleep quality, insomnia, and short sleep. They were measured by the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), and one question "How many hours of sleep did you usually get during the past week?", respectively. Sleep behaviors included sleep hygiene and bedtime procrastination measured by the Sleep Hygiene Index (SHI) and Bedtime Procrastination Scale (BPS), respectively. Logistic regression was performed while controlling for potential confounders. RESULTS: A total of 464 health science students participated. Poorer overall sleep hygiene and more bedtime procrastination were independently associated with higher odds of poor sleep quality (OR=1.065, 95% CI 1.028-1.103; OR=1.040, 95% CI 1.006-1.075, respectively) and insomnia (OR=1.059, 95% CI 1.018-1.101; OR=1.093, 95% CI 1.049-1.139, respectively). More bedtime procrastination was associated with higher odds of short sleep (OR=1.148, 95% CI 1.093-1.206). Commonly reported specific sleep behaviors, such as "Going to bed later than intended", "Doing other things than sleep at bedtime", and "Easily stopping what I am doing at bedtime", were also related to higher odds of sleep disturbances. CONCLUSIONS: Sleep hygiene and bedtime procrastination were strong predictors of sleep disturbances. Tailored interventions targeting specific sleep behaviors are warranted to clarify their effect on sleep disturbances.

Response characteristics of highland barley under freeze-thaw, drought and artemisinin stresses.

The freeze-thaw of early spring in China's Qinghai-Tibet Plateau is often accompanied by severe droughts. Artemisia annua, widely distributed in China, releases allelopathic substances, mainly artemisinin, to the environment and exerts a wide range of effects on crops. This paper studied the physiological effects of highland barley under freeze-thaw, drought, and artemisinin stress through indoor simulation experiments. The physiological response characteristics of superoxide dismutase (SOD) activity, catalase (POD) activity, net photosynthetic rate, relative water content (RWC), relative electrical conductivity, malondialdehyde (MDA) content, and soluble protein content in highland barley were analyzed. The results showed that artemisinin and drought contributed to the increase of SOD activity and the decrease of POD activity. Under the freeze-thaw stress, the SOD and POD activities both decreased firstly and then increased, but the effect of compound stress on POD was more complicated. Either artemisinin, drought, or low temperature could reduce the net photosynthetic rate of highland barley. Low temperature had more significant impacts on photosynthesis, and compound stress would show a single stress superimposed effect. Artemisinin, drought, and low temperature could reduce the RWC of highland barley, and increase the relative electrical conductivity and the concentration of soluble protein (except for low temperature stress above zero, which reduces the concentration of soluble protein). However, the effect of compound stress on soluble protein is more complex. The single stress of artemisinin and drought had no obvious effect on MDA content, while the MDA content was increased significantly under the freeze-thaw stress and the compound stress of artemisinin and drought, and the MDA content reached its peak at T1. The results are helpful to explore the effects of freeze-thaw, drought and artemisinin stress on the growth of highland barley under the background of the aridification of the Qinghai-Tibet Plateau, and provide ideas for rational agricultural management.

Numerical Optimization Study of Combustion and Heat Transfer Characteristics in Municipal Solid Waste Incinerators.

The efficient and clean utilization of urban waste can substitute for partial fossil fuels and reduce total carbon emissions. Fuel combustion is divided into three stages. Before the fire, the fuel is put into the furnace to reach the preparation stage of the fire temperature, the combustion stage takes place after the ignition temperature is reached, and finally, the combustion is completed. This article employs numerical simulation methods to comprehensively study the effects of various factors on the combustion characteristics of waste in a mechanical grate incinerator, including the inclination angle of the front arch, fuel properties, height of the front and rear arches, air distribution methods, and speed of the grate chain rotation. The results indicate that when the rear arch angle is set at 25°, the airflow distribution within the furnace is uniform and the high-temperature flue gas exhibits an ideal "L" shaped flow, achieving favorable characteristics of airflow distribution inside the furnace. With this structure, the airflow from the rear arch can adequately penetrate deep into the front arch area, thereby forming an efficient T-shaped combustion flame.

Cinnamaldehyde-modified chitosan hybrid nanoparticles for DOX delivering to produce synergistic anti-tumor effects.

Cancer cells are under oxidative stress associated with the increased generation of reactive oxygen species (ROS). Therefore, increasing the oxidative stress of tumor cells by delivering ROS generators is an effective strategy to induce apoptosis of cancer cells. Herein, we reported a hybrid nanoparticle based on lactobionic acid (LA) modified chitosan and cinnamaldehyde (CA) modified chitosan, which possesses both active tumor-targeting ability and ROS regulation ability, in order to have a synergistic effect with the anti-tumor drug doxorubicin (DOX). LA can improve the tumor-targeting ability and cellular accumulation of these nanoparticles, and CA can induce apoptotic cell death through ROS generation, mitochondrial permeability transition and caspase activation. The particle size and distribution as well as drug release profiles of these nanoparticles were observed. In vitro and in vivo antitumor studies demonstrated that the hybrid nanoparticles show a significant synergistic antitumor effect. Thus, we anticipate that the hybrid nanoparticles have promising potential as an anticancer drug carrier.