Solvent-Responsive Reversible and Controllable Conversion between a Polyimine Membrane and an Organic Molecule Cage.

Adaptive bionic self-correcting behavior offers an attractive property for chemical systems. Here, based on the dynamic feature of imine formation, we propose a solvent-responsive strategy for smart switching between an amorphous ionic polyimine membrane and a crystalline organic molecule cage without the addition of other building blocks. To adapt to solvent environmental constraints, the aldehyde and amine components undergo self-correction to form a polymer network or a molecular cage. Studies have shown that the amorphous film can be switched in acetonitrile to generate a discrete cage with bright birefringence under polarized light. Conversely, the membrane from the cage crystal conversion can be regained in ethanol. Such a membrane-cage interconversion can be cycled continuously at least 5 times by switching the two solvents. This work builds a bridge between the polymer network and crystalline molecules and offers prospects for smart dynamic materials.

[Characterization of VOCs Emissions from Caged Broiler House in Winter].

Volatile organic compound (VOCs) emissions from poultry and livestock facilities affect the surrounding environmental quality and human health. However, VOCs emissions from broiler houses have been less characterized, and studies of related dominant odorants, carcinogenic risk, and ozone formation potential are still lacking. To fill this research gap, VOCs pollutants emitted from a broiler house were investigated in this study. The VOCs emission characteristics of the broiler house during three different periods of broiler growth (early, middle, and later) were analyzed using gas chromatography-mass spectrometry. The results showed that 77 types of VOCs were detected, including 16 types of halogenated hydrocarbons, 21 types of alkanes, 5 types of olefins, 12 types of aromatic hydrocarbons, 15 types of oxygenated volatile organic compounds (OVOCs), and 8 types of sulfides. During the entire 42-day growth period, the concentrations of halogenated hydrocarbons, alkanes, olefin, aromatic hydrocarbons, and OVOCs in the broiler house showed few changes. However, with the growth of broilers, the intake of sulfur-containing amino acids and the fecal emission coefficient increased, resulting in the gradual conversion of the VOCs to sulfide. Therefore, emissions of sulfur-containing VOCs increased in the early and middle growth periods. Moreover, the increase in ventilation in the house during the later growth period resulted in a decrease in the sulfur-containing VOCs concentrations. The dominant odorants in the broiler house were naphthalene, ethyl acetate, acetaldehyde, carbon disulfide, dimethyl disulfide, methanethiol, methanethiol, and thiophene. Methanethiol had the highest odorous values, ranging from 2172.4 to 19090.9. Meanwhile, there were acceptable levels of carcinogenic risk in the early and middle growth periods, with a lifetime cancer risk (LCR) of 7.7×10-6 and 4.5×10-6, respectively. The average ozone formation potential (OFP) was (1458.9±787.4) µg·m-3. The results of this study can provide a scientific basis for the monitoring of malodorous substances and formulation of emission reduction strategies in broiler production.

The Role of Incubation Conditions on the Regulation of Muscle Development and Meat Quality in Poultry.

Muscle is the most abundant edible tissue in table poultry, which serves as an important source of high protein for humans. Poultry myofiber originates in the early embryogenic stage, and the overall muscle fiber number is almost determined before hatching. Muscle development in the embryonic stage is critical to the posthatch muscle growth and final meat yield and quality. Incubation conditions including temperature, humidity, oxygen density, ventilation and lighting may substantially affect the number, shape and structure of the muscle fiber, which may produce long-lasting effect on the postnatal muscle growth and meat quality. Suboptimal incubation conditions can induce the onset of myopathies. Early exposure to suitable hatching conditions may modify the muscle histomorphology posthatch and the final muscle mass of the birds by regulating embryonic hormone levels and benefit the muscle cell activity. The elucidation of the muscle development at the embryonic stage would facilitate the modulation of poultry muscle quantity and meat quality. This review starts from the physical and biochemical characteristics of poultry myofiber formation, and brings together recent advances of incubation conditions on satellite cell migration, fiber development and transformation, and subsequent muscle myopathies and other meat quality defects. The underlying molecular and cellular mechanisms for the induced muscle growth and meat quality traits are also discussed. The future studies on the effects of external incubation conditions on the regulation of muscle cell proliferation and meat quality are suggested. This review may broaden our knowledge on the regulation of incubation conditions on poultry muscle development, and provide more informative decisions for hatchery in the selection of hatching parameter for pursuit of more large muscle size and superior meat quality.