15 research outputs found
Degradable Nursery Containers Made of Rice Husk and Cornstarch Composites
The degradation behavior was investigated for eco-composite nursery containers (NCs) prepared with rice husk and cornstarch adhesive modified with urea formaldehyde (UF) as a wet strength agent. The wet shear strength, water absorption capacities, and biological degradation of NCs within soil were also investigated. Quantitative analysis of the thermal degradation behavior of different NC versions was performed by thermo-gravimetric analysis (TGA). The results demonstrated that the introduction of the UF agent accelerated the soil degradation of the NCs matrix to a certain extent. The maximum cumulative mass loss was 51.1% when the UF content of NCs was 8 wt.%. Moreover, the dry strength of the mixed urea formaldehyde-cornstarch adhesive (UCA) was increased by 108.9% compared with cornstarch adhesive (CA). The results of this work indicate the improved biodegradability of the NC eco-composites, which could make them potential sustainable alternatives for conventional plastic pots
Preparation and Degradation of Seedling Containers Made from Straw and Hydrolyzed Soy Protein Isolate Modified Urea-Formaldehyde Resins
Straw powders were blended with hydrolyzed soy protein isolate (HSPI) modified urea-formaldehyde (UF) resins to produce biodegradable seedling containers. The tensile strength and the degradability of the seedling containers were characterized. Moreover, the degradation behavior of modified UF resins was investigated using 15N isotopic tracing, dynamic mechanical analysis, 13C CP/MAS NMR spectroscopy, and a scanning electron microscope-energy dispersive spectrometer. The results showed that the best tensile strength of the seedling containers made from HSPI-modified UF resins was improved by 6% compared with the seedling containers made from UF resins. The degradability of the seedling containers made from modified UF resins was improved 8.8 times more than that of unmodified UF resins. HSPI can lower the cross-linking degree of UF resins. The HSPI and urea-formaldehyde molecular chains in the resins were decomposed simultaneously in the soil. After degradation, nodular particles that appeared to be coalesced by small globular particles remained. In the process of degradation, modified UF resins can provide a nitrogen source for crops
Physical, Chemical, and Rheological Properties of Rice Husks Treated by Composting Process
A composting treatment was employed in an effort to improve the processability of rice husks. Changes in the chemical composition, physical structure, and rheological properties of modified rice husks were analyzed. The results indicated that the average diameter of compost-treated samples was significantly higher than that of the untreated samples because they were able to adhere to each other by the bacterial protein. Scanning electron microscopy images showed that the epidermis became rugged and lumpy because the composition of rice husks (cellulose, hemicellulose, lignin, and pectin) was partially decomposed, an effect confirmed by the chemical composition and FTIR analysis. Thermogravimetric analysis showed that the composted samples had better thermal stability than the untreated ones. Stress-strain curves showed that the treated samples displayed a moderately significant change of slope at about 0 to 10% strain, and they had better mechanical properties than untreated samples. Juxtaposing the rheological properties of both untreated and treated samples determined that the latter had higher apparent viscosity as a result of degradation and bacterial protein effects. All results indicated that the composting treatment changed the physical, chemical, and rheological properties of the rice husks, which are beneficial for its utilization and processability
Enhanced Methane Production from Anaerobic Co-Digestion of Wheat Straw and Herbal-Extraction Process Residues
The efficient biosynthesis of methane from renewable biomass resources is discussed in this paper. Herbal-extraction process residues (HPR) are an excellent raw material for anaerobic digestion because of their abundant trace elements and fermentation stability. Anaerobic co-digestion of wheat straw with HPR was evaluated at HPR/wheat straw ratios (based on total solids (TS), of wheat straw) of 3%, 5%, and 10% with anaerobic sludge at 35±1 °C during 30-d anaerobic digestion. The best performance was achieved with 5% HPR added to the reactor, with cumulative methane production of 13,130 mL and cumulative methane yield of 260.5 mL/g TSadded, respectively. Cumulative methane production increased by 31.4% compared to the 9995 mL achieved in mono-digestion with wheat straw. Furthermore, higher activities of protease and total dehydrogenase and higher ATP levels were displayed during the co-digestion process. The high methane yield in this study demonstrates the great potential of co-digestion of renewable biomass as a feedstock for the economical production of methane
The Effects of UV-A on Dry Rice Straw Decomposition under Controlled Laboratory Conditions
In arid and semi-arid areas, organic matter decomposition is stimulated by ultraviolet radiation. In this paper, the association between straw decomposition and UV-A exposure was evaluated. Oven-dried rice straw samples were chronically exposed to UV-A radiation and examined periodically for up to 90 days at room temperature. Scanning electron microscopy (SEM) showed that noticeable disintegration of the fiber structure occurred on the irradiated sample surface in comparison to the control. At the end of the UV-A treatment period, straw mass had decreased by 5%, and dissolved organic carbon (DOC) increased by 18%. The content of cellulose, hemicellulose, and lignin of the irradiated straw decreased by 29.3%, 14.4% and 49.3%, respectively. The marked loss of nitrogen and potassium in the exposed straw were also observed. Thermogravimetric analysis (TGA) showed that treatment with UV-A radiation tended to decrease the mass loss rate and the thermal degradation temperature of the straw biomass from 220 °C to 208 °C. Infrared spectrometric analysis (ATR-FTIR) showed that functional groups, e.g., C–OH and C–O–C, were disrupted obviously due to UV-A exposure. These results suggest that ultraviolet-A irradiation facilitates straw decomposition by direct photochemical degradation
Comparative Analysis of Single-stage and Two-stage Fermentation Systems under Various Process Conditions
A comparative study of single-stage fermentation (wet or dry) and two-stage (wet-dry and dry-wet) fermentation systems was carried out under medium temperature conditions. The effect of the length of the first wet or dry fermentation stage (5-, 10-, 15-, 20-, and 25-d) in the two-stage anaerobic fermentation was investigated. The results showed that the gas production of wet fermentation and two-stage wet-dry fermentation was better than that of the dry fermentation and two-stage dry-wet fermentation. The cumulative gas production increased gradually with increased stage conversion times for the two-stage wet-dry fermentation. The gas production for the 20-d experimental group of the two-stage wet-dry fermentation system was the best. The cumulative biogas production in the anaerobic fermentation of straw correlated significantly with the changes in the degradation rates of volatile solids, cellulose, and hemicellulose (P < 0.01). The kinetic fitting analysis showed that the Reaction Curve (RC) model was more suitable for data modeling of the single-stage wet fermentation and two-stage wet-dry fermentation with straw than the Modified Gompertz (GM) and Modified Logistic (LM) models. The results of this study provided a theoretical basis for choosing a fermentation process for large-scale biogas production with straw
Comparative analysis of the hypothalamus transcriptome of laying ducks with different residual feeding intake
ABSTRACT: Feed costs account for approximately 60 to 70% of the cost of poultry farming, and feed utilization is closely related to the profitability of the poultry industry. To understand the causes of the differences in feeding in Shan Partridge ducks, we compared the hypothalamus transcriptome profiles of 2 groups of ducks using RNA-seq. The 2 groups were: 1) low-residual feed intake (LRFI) group with low feed intake but high feed efficiency, and 2) high-residual feed intake (HRFI) group with high feed intake but low feed efficiency. We found 78 DEGs were enriched in 9 differential Kyoto Encyclopedia of Genes and Genome (KEGG) pathways, including neuroactive ligand-receptor interaction, GABAergic synapse, nitrogen metabolism, cAMP signaling pathway, calcium signaling pathway, nitrogen metabolism, tyrosine metabolism, ovarian steroidogenesis, and gluconeogenesis. To further identify core genes among the 78 DEGs, we performed protein-protein interaction and coexpression network analyses. After comprehensive analysis and experimental validation, 4 core genes, namely, glucagon (GCG), cholecystokinin (CCK), gamma-aminobutyric acid type A receptor subunit delta (GABRD), and gamma-aminobutyric acid type A receptor subunit beta1 (GABRB1), were identified as potential core genes responsible for the difference in residual feeding intake between the 2 breeds. We also investigated the level of cholecystokinin (CCK), neuropeptide Y (NPY), peptide YY (PYY), ghrelin, and glucagon-like peptide1 (GLP-1) hormones in the sera of Shan Partridge ducks at different feeding levels and found that there was a difference between the 2 groups with respect to GLP-1 and NPY levels. The findings will serve as a reference for future research on the feeding efficiency of Shan Partridge ducks and assist in promoting their genetic breeding
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Association of Tirofiban With Functional Outcomes After Thrombectomy in Acute Ischemic Stroke Due to Intracranial Atherosclerotic Disease.
BACKGROUND AND OBJECTIVE: To investigate the efficacy and safety of IV infusion of tirofiban before endovascular thrombectomy for patients with large vessel occlusion due to intracranial atherosclerotic disease. The secondary objective was to identify potential mediators for the clinical effect of tirofiban. METHODS: Post hoc exploratory analysis of the Endovascular Treatment With versus Without Tirofiban for Patients with Large Vessel Occlusion Stroke (RESCUE BT) trial, which was a randomized, double-blinded, placebo-controlled trial at 55 centers in China from October 2018 to October 2021. Patients with occlusion of the internal carotid artery or middle cerebral artery due to intracranial atherosclerosis were included. The primary efficacy outcome was the proportion of patients achieving functional independence (defined as modified Rankin scale 0-2) at 90 days. Binary logistic regression and causal mediation analyses were used to estimate the treatment effect of tirofiban and the potential mediators. RESULTS: This study included 435 patients, of whom 71.5% were men. The median age was 65 (interquartile range [IQR] 56-72) years, with a median NIH Stroke Scale of 14 (IQR 10-19). Patients in the tirofiban group had higher rates of functional independence at 90 days than patients in the placebo group (adjusted odds ratio 1.68; 95% CI 1.11-2.56, p = 0.02) without an increased risk of mortality or symptomatic intracranial hemorrhage. Tirofiban was associated with fewer thrombectomy passes (median [IQR] 1 [1-2] vs 1 [1-2], p = 0.004), which was an independent predictor of functional independence. Mediation analysis showed tirofiban-reduced thrombectomy passes explained 20.0% (95% CI 4.1%-76.0%) of the effect of tirofiban on functional independence. DISCUSSION: In this post hoc analysis of the RESCUE BT trial, tirofiban was an effective and well-tolerated adjuvant medication of endovascular thrombectomy for patients with large vessel occlusion due to intracranial atherosclerosis. These findings need to be confirmed in future trials. TRIAL REGISTRATION INFORMATION: The RESCUE BT trial was registered on the Chinese Clinical Trial Registry: chictr.org.cn, ChiCTR-INR-17014167. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that tirofiban plus endovascular therapy improves 90-day outcome for patients with large vessel occlusion due to intracranial atherosclerosis