ABSTRACT
The value-added utilization of tobacco stalk lignin is the key to the development of tobacco stalk resources. However, the serious heterogeneity is the bottleneck for making full use of tobacco stalk lignin. Based on this, lignin was separated from tobacco stalk through hydrothermal assisted dilute alkali pretreatment. Subsequently, the tobacco stalk alkaline lignin was fractionated into five uniform lignin components by sequential solvent fractionation. Advanced spectral technologies (FT-IR, NMR, and GPC) were used to reveal the effects of hydrothermal assisted dilute alkali pretreatment and solvent fractionation on the structural features of tobacco stalk lignin. The lignin fractions extracted with n-butanol and ethanol had low molecular weight and high phenolic hydroxyl content, thus exhibiting superior chemical reactivity and antioxidant capacity. By contrast, the lignin fraction extracted with dioxane had high molecular weight and low reactivity, nevertheless, the high residual carbon rate made it suitable as a precursor for preparing carbon materials. In general, hydrothermal assisted dilute alkali pretreatment was proved to be an efficient method to separate lignin from tobacco stalk, and the application of sequential solvent fractionation to prepare lignin fractions with homogeneous structural features has specific application prospect.
ABSTRACT
Zeolite Beta single crystals with intracrystalline hierarchical porosity at macro-, meso-, and micro-length scales can effectively overcome the diffusion limitations in the conversion of bulky molecules. However, the construction of large zeolite Beta single crystals with such porosity is a challenge. We report herein the synthesis of hierarchically ordered macro-mesoporous single-crystalline zeolite Beta (OMMS-Beta) with a rare micron-scale crystal size by an inâ situ bottom-up confined zeolite crystallization strategy. The fully interconnected intracrystalline macro-meso-microporous hierarchy and the micron-sized single-crystalline nature of OMMS-Beta lead to improved accessibility to active sites and outstanding (hydro)thermal stability. Higher catalytic performances in gas-phase and liquid-phase acid-catalyzed reactions involving bulky molecules are obtained compared to commercial Beta and nanosized Beta zeolites. The strategy has been extended to the synthesis of other zeolitic materials, including ZSM-5, TS-1, and SAPO-34.
ABSTRACT
OBJECTIVE: To evaluate the therapeutic effect and safety of acupoint sticking therapy for facial paralysis. METHODS: Search the literatures in the whole paper databank of China figure medical library (Jan. 1994-Dec. 2004) and China Biomedical Literature Disk Databank (Jan. 1995-Dec. 2004). Meta-analysis was conducted with RevMan 4. 2. 5 software. RESULTS: Sixteen controlled trials involving 2 157 patients were included. Meta-analysis indicated that there was high statistically difference between the acupoint sticking therapy and simple acupuncture therapy or Western medicine therapy. CONCLUSION: The acupoint sticking therapy is effective and safe for facial paralysis.
Subject(s)
Acupuncture Points , Facial Paralysis , Acupuncture Therapy , China , HumansABSTRACT
OBJECTIVE: To assess the efficacy and safety of bifid triple viable bacterial tablet in treatment of infantile diarrhea. METHODS: According to the requirements of Cochrane systematic review, a thorough literature search was performed among Chinese Digital Hospital Library (www.chkd.cnki.net) and Chinese Biomedical Literature Disk Database (CBMdisk). A meta analysis was performed on a total of 1326 patients involved in 12 papers which met the inclusion criteria. RESULTS: Publication bias analysis showed that the funnel plot was symmetrical. Test for heterogeneity showed that the groups treated with bifid triple viable bacterial tablet and antibiotics or anti-viral agents or placebo control had clinical homogeneity and statistical homogeneity (P = 0.66, 0.67, 0.85, respectively, I(2) = 0%), which allowed to use fixed effect model analysis. The bifid triple viable bacterial tablet and Smecta did not have statistical homogeneity (P = 0.02, I(2) = 70.9%), therefore random effect model analysis was applied. Incorporation analysis showed that in comparison of the bifid triple viable bacterial tablet versus antibiotics or anti-viral agents or placebo control, the odds ratios were 5.34, 4.74 and 6.43, respectively, and 95% CIs were [2.81, 10.16], [2.47, 9.09], and [2.61, 15.83], on test for overall effect, Z = 5.11, 4.67 and 4.04, P < 0.00001. In the forest plot the 95% CI horizontal line of incorporation odds ratio droped to the right side of the vertical line indicating the border of effectiveness. However, no statistically significant difference was found between bifid triple viable bacterial tablet and Smecta. CONCLUSION: The clinical evidences available so far indicated that treatment of infantile diarrhea with bifid triple viable bacterial tablet is safe and effective although rigorously designed large sample size randomized double blind clinical trials are required to further demonstrate and support the conclusion.
