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FATE AND METABOLISM OF NITROGEN IN GOATS FED 15N-LABELLED RICE STRAW

  • Xing, T.X.;He, D.Y.;He, L.H.;Zhou, W.J.;Liao, X.L.;Chen, H.P.
    • Asian-Australasian Journal of Animal Sciences
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    • v.5 no.4
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    • pp.699-707
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    • 1992
  • Three goats were fed with $^{15}N$-labelled rice straw to study the characteristics of digestion, assimilation, metabolism and excretion of C and N compounds from rice straw. It was shown that the amount of $^{15}N$ assimilated into the bodies of the two slaughtered goats accounted for 38.5 and 23.6% of the total amount of $^{15}N$ ingestion in the experimental diet by each goat. The $^{15}N$ excreted via the feces and urine for the three goats accounted for 34.8, 33.2 and 33.9% of the total amount of $^{15}N$ ingested in the feed of the 3 goats. The recoveries of $^{15}N$ from the two slaughtered goats were 73.3 and 57.5%, with the corresponding rates of $^{15}N$ loss 26.7 and 42.5% respectively. The amino acids digestibilities were 68.7 and 54.0%, while the digestibilities of carbohydrates were 74.8 and 67.7% respectively for goats 1 and 3.

Preparation and Drug-releasing Properties of Chitosan-based Thermosensitive Composite Hydrogel

  • Li, Heping;Yu, Tao;Li, Shan;Qin, Long;Ning, Jingheng
    • Journal of the Korean Chemical Society
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    • v.56 no.4
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    • pp.473-477
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    • 2012
  • The novel chitosan-based thermosensitive hydrogels were prepared as control-releasing drug carriers. N-carboxyethyl chitosan (ACS) was synthesized by microwave heating for 1 h through Michael addition of CS to acrylic acid in a grafting yield of 52.97%, which was proved to be a faster and more efficient way than ordinary methods. 5-Fu was modified with formaldehyde to synthesize N,N'-Bis(hydroxymethyl)-5-fluorouracil (5-Fu-OH). Then an esterification was performed using ACS and 5-Fu-OH to give 5-Fu-ACS. The new thermosensitive hydrogels were prepared by adding sodium glycerophosphate to the solution of compounds under a certain constant temperature. Simultaneously, the hydrogels' swelling rate, in vitro drug release rate and thermosensitive were studied, and found that the 5-Fu-ACS composite hydrogel had more excellent releasing effect, higher drug loading and better thermosensitive.

Plastic deformation characteristics of disintegrated carbonaceous mudstone under dynamic loading

  • Qiu, Xiang;Yin, Yixiang;Jiang, Huangbin;Fu, Sini;Li, Jinhong
    • Geomechanics and Engineering
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    • v.31 no.1
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    • pp.87-97
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    • 2022
  • The excessive settlement and deformation of disintegrated carbonaceous mudstone (DCM) embankments under dynamic loading have long been problems for engineers and technicians. In this work, the characteristics and mechanism of the plastic deformation of DCM under different degrees of compaction, water contents and confining pressures were studied by static triaxial, dynamic triaxial and scanning electron microscopy testing. The research results show that the axial stress increases with increasing confining pressure and degree of compaction and decreases with increasing water content when DCM failure. The axial strain at failure of the DCM decreases with increasing confining pressure and degree of compaction and increases with increasing water content. Under cyclic dynamic stress, the change in the axial stress level of the DCM can be divided into four stages: the stable stage, transition stage, safety reserve stage and unstable stage, respectively. The effects of compaction, water content and confining pressure on the critical axial stress level which means shakedown of the DCM are similar. However, an increase in confining pressure reduces the effects of compaction and water content on the critical axial stress level. The main deformation of DCM is fatigue cracking. Based on the allowable critical axial stress, a method for embankment deformation control was proposed. This method can determine the degree of compaction and fill range of the embankment fill material according to the equilibrium moisture content of the DCM embankment.

Vibration suppression analysis of a long-span cable-stayed bridge based on earthquake-wind-traffic-bridge coupled system

  • Xinfeng Yin;Yong Liu;Wanli Yan;Yang Liu;Zhou Huang
    • Structural Engineering and Mechanics
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    • v.88 no.4
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    • pp.379-387
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    • 2023
  • Wind and earthquake loads may cause strong vibrations in large-span cable-stayed bridges, leading to the inability of the bridge to operate normally. An improved Pounding Tuned Mass Damper (PTMD) system was designed to improve the safety of the large-span cable-stayed bridge. The vibration control effect of the improved PTMD system on the large-span cablestayed bridge under the combined action of earthquake-wind-traffic was studied. Furthermore, the impact of different parameters on the vibration suppression performance of the improved PTMD system was analyzed. The numerical results indicate that the PTMD system is very effective in suppressing the displacements of the bridge caused by both the traffic-wind coupling and traffic-earthquake coupling. Moreover, the number, mass ratio, pounding stiffness, and gap values have a significant influence on the vibration suppression performance of the improved PTMD system. When the number of PTMD is increased from 3 to 9, the vibration reduction ratio of the vertical displacement is increased from 25.39% to 48.05%. As the mass ratio changes from 0.5% to 2%, the vibration reduction ratio increases significantly from 22.23% to 53.30%.

A Label-Free Fluorescent Amplification Strategy for High-Sensitive Detection of Pseudomonas aeruginosa based on Protective-EXPAR (p-EXPAR) and Catalytic Hairpin Assembly

  • Lu Huang;Ye Zhang;Jie Liu;Dalin Zhang;Li Li
    • Journal of Microbiology and Biotechnology
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    • v.34 no.7
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    • pp.1544-1549
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    • 2024
  • This study presents a fluorescent mechanism for two-step amplification by combining two widely used techniques, exponential amplification reaction (EXPAR) and catalytic hairpin assembly (CHA). Pseudomonas aeruginosa (P. aeruginosa) engaged in competition with the complementary DNA in order to attach to the aptamer that had been fixed on the magnetic beads. The unbound complementary strand in the liquid above was utilized as a trigger sequence to initiate the protective-EXPAR (p-EXPAR) process, resulting in the generation of a substantial quantity of short single-stranded DNA (ssDNA). The amplified ssDNA can initiate the second CHA amplification process, resulting in the generation of many double-stranded DNA (dsDNA) products. The CHA reaction was initiated by the target/trigger DNA, resulting in the release of G-quadruplex sequences. These sequences have the ability to bond with the fluorescent amyloid dye thioflavin T (ThT), generating fluorescence signals. The method employed in this study demonstrated a detection limit of 16 CFU/ml and exhibited a strong linear correlation within the concentration range of 50 CFU/ml to 105 CFU/ml. This method of signal amplification has been effectively utilized to create a fluorescent sensing platform without the need for labels, enabling the detection of P. aeruginosa with high sensitivity.