Effects of chitosan and rice husk powder on thermal hydrolysis-anaerobic digested sludge conditioning: Dewaterability and biogas slurry fertility.

To enhance the dewaterability of anaerobic digested sludge and to make full use of the biogas slurry. This study set up five sludge conditioning methods: polymeric ferric sulfate, polymeric aluminum chloride, cationic polyacrylamide, chitosan, and chitosan combined with rice husk powder. Their effects on the dewaterability of thermal hydrolysis-anaerobic digested sludge, bacterial community, and biogas slurry fertility were studied to find a non-toxic and non-risk dewatering technology for the environment and biogas slurry. Compared with that of the control group, moisture content, normalization capillary suction time, and specific resistance to filtration were reduced by 12.8%, 97.7%, and 82.9%, respectively. Chitosan enlarges the sludge flocs and forms complexes with proteins, disrupting the structure of the extracellular polymeric substances, thereby exposing more hydrophobic groups and reducing the hydrophilicity of the sludge. The subsequent addition of rice husk powder enhances the adsorption of hydrophilic substances and provides a stronger drainage channel for the sludge. In addition, the biogas slurry obtained by this conditioning method used as a fertilizer increased the dry weight and fresh weight of corn seedlings by 59.3% and 91.0%, respectively. And the total chlorophyll content increased by 84.6%. Pearson's correlation analysis showed that chitosan and rice husk meal had no toxic effect on the biogas slurry compared to the other three flocculants. The results showed that the combined treatment of chitosan and rice husk powder resulted in the best dewaterability. Overall, chitosan combined with rice husk powder is a green dewatering technology with great potential for anaerobic digested sludge dewatering and biogas slurry recycling.

Comparison of Thermophilic-Mesophilic and Mesophilic-Thermophilic Two-Phase High-Solid Sludge Anaerobic Digestion at Different Inoculation Proportions: Digestion Performance and Microbial Diversity.

This study investigated the performance of thermophilic-mesophilic (T-M) and mesophilic-thermophilic (M-T) two-phase sludge anaerobic digestion at different inoculation proportions after a change in digestion temperature. After temperature change, the pH, total ammonia nitrogen (TAN), free ammonia nitrogen (FAN), solubility chemical oxygen demand (SCOD), and total alkalinity (TA) levels of two-phase digesters were between thermophilic control digesters and mesophilic control digesters. However, the volatile fatty acid (VFA) levels of two-phase digesters were higher than those of thermophilic or mesophilic control digesters. The bacteria communities of M-T two-phase digesters were more diverse than those of T-M. After a change in digestion temperature, the bacterial community was dominated by Coprothermobacter. After a change of digestion temperature, the relative abundance (RA) of Methanobacterium, Methanosaeta, and Methanospirillum of M-T two-phase digesters was higher than that of T-M two-phase digesters. In comparison, the RA of Methanosarcina of T-M two-phase digesters was higher than that of M-T two-phase digesters. The ultimate methane yields of thermophilic control digesters were greater than those of mesophilic control digesters. Nevertheless, the ultimate methane yield levels of M-T two-phase digesters were greater than those of T-M two-phase digesters. The ultimate methane yields of all two-phase digesters presented an earlier increase and later decrease trend with the increasing inoculation proportion. Optimal methane production condition was achieved when 15% of sludge (T-M15) was inoculated under mesophilic-thermophilic conditions, which promoted 123.6% (based on mesophilic control) or 27.4% (based on thermophilic control). An optimal inoculation proportion (about 15%) balanced the number and activity of methanogens of high-solid sludge anaerobic digestion.

Genome-wide identification and characterization of the HSP gene superfamily in apple snails (Gastropoda: Ampullariidae) and expression analysis under temperature stress.

Apple snails from the family Ampullariidae have become economically important due to several species mainly from the genus Pomacea being invasive. The heat shock proteins (HSPs), which are important molecular chaperones for species responding to various stresses, have been proved to play critical roles in adapting harsh environments in the invasive apple snails. The recent release of the genomes of Pomacea canaliculata, Pomacea maculata, Lanistes nyassanus, and Marisa cornuarietis has opened the opportunity for a comprehensive analysis of HSP superfamily in the ampullariids. We identified the number of HSP from P. canaliculata (PcaHSPs) was greater than that from the other three species. A total of 42 PcaHSPs were distributed on 12 chromosomes and were classified into the families of HSP90, HSP70, HSP60, HSP40, HSP20, and HSP10. Each family formed a monophyletic clade on the phylogenetic tree with strong support values, except for the HSP90 and HSP70 families. The RNA-seq data shows that most the PcaHSPs were of tissue-specific expression levels. Moreover, we identified more HSP genes with stronger transcription levels in response to heat than cold stress. Our findings are informative for future studies on stress adaptation and developing effective management strategies focusing on HSPs in invasive apple snails.

Neural responsiveness to Chinese versus Western food images: An functional magnetic resonance imaging study of Chinese young adults.

Cross-cultural studies suggest that people typically prefer to eat familiar foods from their own culture rather than foreign foods from other cultures. On this basis, it is plausible that neural responsiveness elicited by palatable food images from one's own culture differ from those elicited by food depictions from other cultures. Toward clarifying this issue, we examined neural activation and self-report responses to indigenous (Chinese) versus Western food images among young Chinese adults. Participants (33 women, 33 men) viewed Chinese food, Western food and furniture control images during a functional magnetic resonance imaging (fMRI) scan and then rated the images on "liking," "wanting," and "difficult resisting." Analyses indicated there were no significant differences in self-report ratings of Chinese versus Western food images. However, Chinese food images elicited stronger activation in regions linked to cravings, taste perception, attention, reward, and visual processing (i.e., cerebellum crus, superior temporal gyrus, supramarginal gyrus, middle temporal gyrus, inferior parietal lobule, posterior insula, middle occipital gyrus; inferior occipital gyrus). Conversely, Western food images elicited stronger activation in areas involved in visual object recognition and visual processing (inferior temporal gyrus, middle occipital gyrus, calcarine). These findings underscored culture as a potentially important influence on neural responses to visual food cues and raised concerns about the ecological validity of using "standard" Western food images in neuroimaging studies of non-Western samples. Results also provide foundations for designing culturally informed research and intervention approaches in non-Westerns contexts guided by the use of external food cues that are most salient to the cultural group under study.

Factor structure, correlates, and incremental validity of the Pain Appraisal Inventory-Short Form.

We assessed the factor structure, correlates, and incremental validity of the Pain Appraisal Inventory in Chinese adult chronic pain samples. In an initial exploratory factor analysis sample (N = 301), the original two-component (threat, challenge) 16-item Pain Appraisal Inventory and a 10-item short form (Pain Appraisal Inventory-Short Form) were supported. Within a confirmatory factor analysis sample (N = 285), uniformly acceptable fits were observed only for the Pain Appraisal Inventory-Short Form. Furthermore, Pain Appraisal Inventory-Short Form threat and challenge subscales had significant correlations with conceptually related measures and added to prediction models for pain-related coping and adjustment, independent of other pain belief scales. Together, results indicated that the Pain Appraisal Inventory-Short Form has utility in Chinese chronic pain samples.