Flow-through strategy to fractionate lignin from eucalyptus with formic acid/hydrochloric solution under mild conditions.

Formic acid is an attractive solvent for the fractionation of lignocellulose for the production of biomaterials and chemicals, while the operation conducted in a batch manner is not conducive to mass transfer in separation process. In this research, eucalyptus was fractionated with formic acid/hydrochloric solution in a flow-through reactor at 95 °C, and the structural characteristics and the composition of fractionated lignin in different stages were investigated. Results showed that the fractionation efficiency was notably improved with a flow-through reactor, as evidenced by the low solid residue yield of 49.5% and the lignin removal rate of 79.4% as compared to the batch manner. During the fractionation process, the dissolution rate of lignin decreased gradually, and the obtained lignin samples showed low molecular weight (<3000), good uniformity (<2), and high thermal stability. The structure analysis showed that ß-O-4, ß-ß, and ß-5 linkages in lignin were degraded to varying degrees with increased time, and the degradation of G units was more severe than S ones.

Hydrothermal liquefaction of lignocellulose for value-added products: Mechanism, parameter and production application.

Abundant, environmentally friendly, and sustainable lignocellulose is a promising feedstock for replacing fossil fuels, and hydrothermal liquefaction is an effective technology to convert it into liquid fuels and high-value chemicals. This review summarizes and discusses the reaction mechanism, main influence factor and the production application of hydrothermal liquefaction. Particular attention has been paid to the reaction mechanism of the structural components of lignocellulose, i.e., cellulose, hemicellulose, and lignin. In addition, the influence factors including types of lignocellulose, temperature, heating rate, retention time, pressure, solid-to-liquid ratio, and catalyst are discussed in detail. The limitations in the hydrothermal liquefaction of lignocellulose and the prospects are proposed. This provides deep knowledge for understanding the process as well as the development of advanced products from lignocellulose.

Tetrahydro-2-furanmethanol pretreatment of eucalyptus to enhance cellulose enzymatic hydrolysis and to produce high-quality lignin.

In this study, an organosolv process based on tetrahydro-2-furanmethanol/acid aqueous solution was developed to release lignin and hemicelluloses from eucalyptus for the enhancement of enzymatic hydrolysis. The pretreatment with 80% THFA aqueous solution containing 1% HCl at a solid to liquid ratio of 1:10 was conducted at 120-180 °C for 30 min. Under the serious conditions, the cellulose-rich residue had a high proportion of cellulose up to 87.31%. The enzymatic hydrolysis rate of the cellulose-rich fraction was 94.18%, which was enhanced by 7.3-fold as compared to that of the raw material without pretreatment. The fractionation process resulted in a high delignification rate of 93.95%. The lignin produced with medium molecular weight (2190 g/mol) and high purity (contaminated sugar content 0.6%) was a good substrate for further application as chemicals.

Capsule endoscopy and single-balloon enteroscopy in small bowel diseases: Competing or complementary?

AIM: To evaluate diagnostic yields of capsule endoscopy (CE) and/or single-balloon enteroscopy (SBE) in patients with suspected small bowel diseases. METHODS: We retrospectively analyzed 700 patients with suspected small bowel diseases from September 2010 to March 2016. CE, SBE, or SBE with prior CE was performed in 401, 353, and 47 patients, respectively. Data from clinical and endoscopy records were collected for analysis. Indications, procedure times, diagnostic yields, and complications were summarized and evaluated. RESULTS: The overall diagnostic yield for the CE group was 57.6%. The diagnostic yield of CE in patients with obscure gastrointestinal bleeding (OGIB) was significantly greater than that in patients with no bleeding (70.5% vs 43.8%, P < 0.01). The overall diagnostic yield of SBE was 69.7%. There was no difference in the diagnostic yield of SBE between patients with OGIB and those with no bleeding (72.5% vs 68.9%, P = 0.534). Forty-seven patients underwent CE prior to SBE. Among them, the diagnostic yield of SBE with positive findings on prior CE was 93.3%. In addition, SBE detected two cases with superficial ulcer and erosive lesions in the small bowel, which were missed by CE. However, one case with lymphoma and two with Crohn's disease were not confirmed by SBE. The rate of capsule retention was 2.0%. There were no significant complications during or after SBE examinations. CONCLUSION: SBE is a safe and effective technique for diagnosing small bowel diseases. SBE with prior CE seemed to improve the diagnostic yield of small bowel diseases.

[Preliminary exploration on submucosal tunneling endoscopic resection for middle and lower esophagus submucosal tumors].

OBJECTIVE: To evaluate the efficacy and safety of submucosal tunneling endoscopic resection (STER) in the treatment of middle and lower esophagus submucosal tumors (SMT) originating from muscularis propria (MP) layer. METHODS: A total number of 33 esophagus submucosal tumor (SMT) originating from MP layer underwent tumor resection by STER after endoscopic ultrasonography (EUS) and CT examination at Endoscopy Center, Department of Gastroenterology, First Affiliated Hospital, Nanjing Medical University from March 2012 to March 2013. There were 17 males and 16 females with an age range of (50 ± 10) years. Their lesion size, lesion origin, pathology, operative duration and complication rate were analyzed. RESULTS: Among them, the origins were of submucosal (n = 4, 12.1%), superficial muscularis propria layer (SMP) (n = 18, 54.6%), deep muscularis layer (DMP) (n = 10, 30.3%) and serosa (n = 1, 3.0%). There were single tumor (n = 30, 90.9%), double tumors (n = 2, 6.1%) and triple tumors (n = 1, 3.0%). Except for 1 case of non-resected hemangioma, 36 operative specimens were examined pathologically, including 30 leiomyomas tumors (83.3%), 5 stromal tumors (GIST) (13.9%) and 1 lipoma tumor (2.8%). Thirty-two lesions were successfully resected by STER with a complete resection rate of 97.0%. Average lesion size was (1.7 ± 1.0) cm and average operative duration (49 ± 26) min. A number of (7.8 ± 2.5) hemostatic clips were used to close the mucosal incision site. Subcutaneous emphysema occurred in 3 patients (9.1%) while puncture and pneumothorax developed in one case (3.0%). All of them recovered uneventfully through conservative treatments. CONCLUSIONS: As a new safe, efficacious and feasible treatment for middle and lower esophagus submucosal tumors, STER may completely resect SMT and provide accurate histopathological evaluations. And it is feasible to regain the mucosal integrity of GI tract and prevent the occurrences of leakage and secondary infections.

3,5-Dihydr-oxy-N'-(2-hydroxy-benzyl-idene)benzohydrazide monohydrate.

The title potential anti-bacterial compound, C(14)H(12)N(2)O(4)·H(2)O, is a Schiff base which has an intra-molecular O-H⋯N hydrogen bond and crystallizes with one uncoordinated water mol-ecule, which links three symmetry-related mol-ecules through two O-H⋯O and one N-H⋯O hydrogen bond. In the crystal structure, further inter-molecular O-H⋯O hydrogen bonds link symmetry-related mol-ecules, forming layers parallel to the bc plane.

[The solubilization effect of 2-hydroxypropyl-beta-cyclodextrin on paeonolum].

OBJECTIVE: To study the solubilization effect of 2-hydroxypropyl-beta-cyclodextrin(HPCD) on paeonolum at various pH value. METHOD: Phase-solubility method was adopted to study the solubilization effect at 25 degrees C and UV spectrohotometer was used to determine paeonolum content. RESULTS: The apparent solubility of paeonolum was significantly enhanced by increased HPCD concentration. The apparent stability constant of paeonolum compounds was calculated up to 1 425 in which pH was 3 and HPCD concentration was 133.33 mmol x L(-1). The solubility of paeonolum came up to 10 mg x mL(-1). CONCLUSION: HPCD is an ideal solubilizer for paeonolum.