RESUMEN
Corn fiber, a by-product from the corn processing industry, mainly composed of residual starch, cellulose, and hemicelluloses, is a promising raw material for producing cellulosic ethanol and value-added products due to its abundant reserves and low costs of collection and transportation. Now, several technologies for the production of cellulosic ethanol from corn fiber have been reported, such as the D3MAX process, Cellerate™ process, etc., and part of the technologies have also been used in industrial production in the United States. The ethanol yields range from 64 to 91% of the theoretical maximum, depending on different production processes. Because of the multicomponent of corn fiber and the complex structures highly substituted by a variety of side chains in hemicelluloses of corn fiber, however, there are many challenges in cellulosic ethanol production from corn fiber, such as the low conversion of hemicelluloses to fermentable sugars in enzymatic hydrolysis, high production of inhibitors during pretreatment, etc. Some technologies, including an effective pretreatment process for minimizing inhibitors production and maximizing fermentable sugars recovery, production of enzyme preparations with suitable protein compositions, and the engineering of microorganisms capable of fermenting hexose and pentose in hydrolysates and inhibitors tolerance, etc., need to be further developed. The process integration of cellulosic ethanol and value-added products also needs to be developed to improve the economic benefits of the whole process. This review summarizes the status and progresses of cellulosic ethanol production and potential value-added products from corn fiber and presents some challenges in this field at present.
RESUMEN
OBJECTIVE: To observe the effect of follicular fluid IL-6, TNF-α on the clinical outcome of in vitro fertilization and embryo transfer (IVF-ET) in patients with ovarian endometriosis. METHOD: From June 2013 to June 2014, the data of 64 (from Tangshan Maternal and Child Health Hospital IVF center) ovarian endometriosis patients was analyzed retrospectively. 58 infertility cases caused by male side were used as control group. Oocyte retrieval rate, M II oocytes rate, fertilization rate, recovery-intracytoplasmic sperm injection (R-ICSI) rate, good quality embryo rate, biochemical pregnancy rate and clinical pregnancy rate were analyzed and compared between two groups. Changes in the expression of follicular fluid IL-6, TNF-α were detected. RESULTS: Oocyte retrieval rate, M II oocytes rate, fertilization rate, good quality embryo rate, biochemical pregnancy rate and clinical pregnancy rate in ovarian endometriosis group were significantly lower than those in the control group (all P < 0.05), while R-ICSI rate increased in ovarian endometriosis group compared with control group (P < 0.05). IL-6, TNF-α expressions of follicular fluid were higher in affected side of ovarian endometriosis patients than those in the unaffected side and those in control group. CONCLUSION: Inflammation microenvironment of the follicular fluid may influence IVF-ET outcomes in ovarian endometriosis patients.
