Homogeneous Degradation of Cellulose in Its Aqueous Solution at Mild Temperature under Atmospheric Pressure

Degradation of cellulose to chemicals is one of major routes for biomass conversion. Here, a new simple and two-step method has been developed to convert cellulose in its homogeneously alkaline solution to organic acids under atmospheric pressure at mild temperature. At first, cellulose was degraded to smM1 molecular intermediates at 110 ℃ for 3 h under atmospheric pressure, and then it was oxidized with H202 at 50 ℃ for 4 h. Under the optimal condition, 73.5% conversion of cellulose could be achieved, and the yield of organic acids was 32.8% （formic acid）, 11.6% （lactic acid）, and 2.3% （oxalic acid）, respectively. It is noteworthy that the new strategy reduces energy consumption in the process of reaction, unlike the hydrothermal reaction under high temperature and high pressure.

Effect of Raw Material for Distillers Grains Production on Protein Quality for Ruminants

The present experiment was focused on quality of dry distillers＇ grains with solubles （DDGS） produced from corn （DDGSc）, wheat （DDGSw）, triticale （DDGSt）, and wet distillers grains from corn （WDGc） for ruminants. The products were tested for dry matter （DM）, crude protein （CP）, neutral detergent fibre （NDF）, acid detergent fibre （ADF） acid detergent insoluble nitrogen （NIAD）, amino acid （AA） profile, CP degradability and intestinal digestibility （ID） of rumen undegraded protein （RUP）. The average content of CP （g/kg DM） ranged from 289.9 （DDGSc） to 356.9 （DDGSw）. The highest content of essential AA was in WDGc （440.1 g/160g N） followed with DDGSc. The most variable was the content of Lys in DDGSw （from 13.69 to 22.79 g/160 g N）. The NIAD was found the highest for DDGSw （from 16.8% to 36.2%）, effective CP degradability was only 50.2% and ID of RUP 82.2%, total essential AA 81.2%, Lys 77.69% and Met 81.4%. Lys was generally the least digestible AA. The ruminally degradable CP fraction was in the range from 52.6% to 70.2% for DDGSc. ID of total and essential by-pass AA was very high 96.2% and 96.1%, Lysine 90.9% and Methionine 96.7%. From these data it can be concluded that DDGS from grains are a good source of protein for ruminants.

Whole meniscus regeneration using polymer scaffolds oaded with fibrochondrocytes

Objective： To study the feasibility of regenerating a whole menisci using poly-（3- hydroxybutyrate-co-3-hydroxyvalerate） （PHBV） scaffolds loaded with meniscal cells in rabbits undergoing total meniscectomy, and to explore its protective effect on carti- lage degeneration. Methods： A solvent casting and particulate leaching technique was employed to fabricate biodegradable PHBV scaffolds into a meniscal shape. The proliferated meniscal cells were seeded onto the polymer scaffolds, transplanted into rabbit knee joints whose lateral menisci had been removed. Eight to 18 weeks after transplantation, the rege- nerated neomenisci were evaluated by gross and histologi- cal observations. Cartilage Mankin score. degeneration was assessed by Results： Eighteen weeks after transplantation, the implants formed neomenisci. Hematoxylin and eosin （HE） staining of the neomenisci sections revealed regeneration of fibrocartilage. Type I collagen in the neomenisci was also proved similar to normal meniscal tissue by immunohis-tochemical analysis and Sirius scarlet trinitrophenol staining. Articular cartilage degeneration was observed 8 weeks af- ter implantation. It was less severe as compared with that in total meniscectomy controls and no further degeneration was observed at 18 weeks. At that time, the regenerated neomenisci strongly resembled normal meniscal fibrocarti- lage in gross and histological appearance, and its mechani- cal property was also close to that of normal meniscus. Conclusions： The present study demonstrates the feasibility of tissue-engineering a whole meniscal structure in total meniscectomy rabbit models using biodegradable PHBV scaffolds together with cultured allogeneic meniscal cells. Cartilage degeneration is decreased. But long-term in vivo investigations on the histological structure and cartilage degeneration of the neomenisci regenerated by this method are still necessary to determine the clinical potential of this tissue engineering avenue.