Photoreforming for Lignin Upgrading: A Critical Review.

Photoreforming of lignocellulosic biomass to simultaneously produce gas fuels and value-added chemicals has gradually emerged as a promising strategy to alleviate the fossil fuels crisis. Compared to cellulose and hemicellulose, the exploitation and utilization of lignin via photoreforming are still at the early and more exciting stages. This Review systematically summarizes the latest progress on the photoreforming of lignin-derived model components and "real" lignin, aiming to provide insights for lignin photocatalytic valorization from fundamental to industrial applications. Considering the complexity of lignin physicochemical properties, related analytic methods are also introduced to characterize lignin photocatalytic conversion and product distribution. We finally put forward the challenges and perspective of lignin photoreforming, hoping to provide some guidance to valorize biomass into value-added chemicals and fuels via a mild photoreforming process in the future.

New translational and experimental insights into the role of pro-resolving lipid mediators in inflammatory bowel disease.

The resolution of inflammation is an active process, guided by specialized pro-resolution lipid mediators (SPMs). These mediators originate from polyunsaturated fatty acids, such as omega-3. Sufficient evidence suggests that the beneficial effects attributed to omega-3 are, at least in part, the result of the immunomodulatory action of the SPMs, which act systemically by overcoming inflammation and repairing tissue damage, without suppressing the immune response. Recent studies suggest that an imbalance in the synthesis and/or activity of these compounds may be associated with the pathogenesis of several inflammatory conditions, such as inflammatory bowel disease (IBD). Thus, this review highlights the advances made in recent years with regard to the endo-genous synthesis and the biological role of lipoxins, resolvins, protectins, and maresins, as well as their precursors, in the regulation of inflammation; and provides an update on the participation of these mediators in the development and evolution of IBD and the therapeutic approaches that these immunomodulating substances are involved in this context.

Coproduction of hydrogen and lactic acid from glucose photocatalysis on band-engineered Zn1-xCdxS homojunction.

Photocatalytic transformation of biomass into value-added chemicals coupled with co-production of hydrogen provides an explicit route to trap sunlight into the chemical bonds. Here, we demonstrate a rational design of Zn1-xCdxS solid solution homojunction photocatalyst with a pseudo-periodic cubic zinc blende (ZB) and hexagonal wurtzite (WZ) structure for efficient glucose conversion to simultaneously produce hydrogen and lactic acid. The optimized Zn0.6Cd0.4S catalyst consists of a twinning superlattice, has a tuned bandgap, and displays excellent efficiency with respect to hydrogen generation (690 ± 27.6 µmol·h-1·gcat. -1), glucose conversion (~90%), and lactic acid selectivity (~87%) without any co-catalyst under visible light irradiation. The periodic WZ/ZB phase in twinning superlattice facilitates better charge separation, while superoxide radical (⋅O2 -) and photogenerated holes drive the glucose transformation and water oxidation reactions, respectively. This work demonstrates that rational photocatalyst design could realize an efficient and concomitant production of hydrogen and value-added chemicals from glucose photocatalysis.

n-p Heterojunction of TiO2-NiO core-shell structure for efficient hydrogen generation and lignin photoreforming.

Hydrogen evolution from biomass photoreforming has been widely recognized as a promising strategy for relieving the pressure from energy crisis and environmental pollution, as it could generate sustainable H2 and value-added bioproducts simultaneously. Combining p-type semiconductors with n-type semiconductors to form n-p heterojunction is an effective strategy to improve the photocatalytic quantum efficiency by enhancing the separation of photogenerated electrons and holes, which could greatly facilitate the realization of such biomass photorefinery concept. However, the incompact contact between the n-type and p-type semiconductors often induces the aggregation of photogenerated electrons and holes. In this work, we design and synthesize an ultrafine n-p heterojunction TiO2-NiO core-shell structure to overcome the incompact contact in the n-p interface. When the n-p heterojunction photocatalysts are evaluated for photocatalytic water splitting and biomass lignin photoreforming respectively, the as-fabricated TiO2-NiO nanocomposite with 3.25% NiO demonstrates the highest hydrogen generation of 23.5 mmol h-1 g-1 from water splitting and H2 (0.45 mmol h-1 g-1) and CH4 (0.03 mmol h-1 g-1) cogeneration with reasonable amount of fatty acids (palmitic acid and stearic acid) production from lignin photoreforming. The excellent photocatalytic activity is ascribed to the synergistic effects of high crystallinity of TiO2 ultrafine nanoparticles, core-shell structure and n-p heterojunction with NiO nanoclusters. This present work demonstrates a simple and efficient method to fabricate ultrafine n-p heterojunction core-shell structure for noble-metal free catalyst for both water splitting and biomass photoreforming.

Histological grading evaluation of non-alcoholic fatty liver disease after bariatric surgery: a retrospective and longitudinal observational cohort study.

Non-alcoholic fatty liver disease (NAFLD) is a chronic disease with several degrees of histological features which may progress to cirrhosis. Obesity is an important risk factor and although NAFLD has no specific pharmacological treatment, bariatric surgery has been associated with NAFLD regression in severely obese patients. However, few longitudinal histological studies support this finding. Therefore, firstly, a retrospective study was performed including clinical and histological data of 895 obese patients who underwent bariatric surgery. In addition, histological analyses of 30 patient's liver biopsies were evaluated at two timepoints (T1 and T2). The retrospective analysis of the total number of patients revealed that the average body mass index (BMI) was 35.91 ± 2.81 kg/m2. The liver biopsies during bariatric surgery showed that 53.52% did not present NAFLD, 30.16% had NASH, 15.98% isolated steatosis and 0.34% liver cirrhosis. The median BMI of the longitudinal cohort decreased from 37.9 ± 2.21 kg/m2 at the time of bariatric surgery (T1) to 25.69 ± 3.79 kg/m2 after 21 ± 22 months after the procedure (T2). The prevalence of NAFLD in T1 was 50%, and 16.67% in T2. The histological area of collagen fiber was lower in T2 compared to T1 (p = 0.0152) in the majority of patients, which was also illustrated by immunohistochemistry for Kupffer cell and myofibroblast formation markers. These findings confirmed the NAFLD regression after bariatric surgery and, for the first time, showed the amelioration of these features using more accurate histopathological techniques.

Risk Factors for Success, Complications, and Death after Endoscopic Sphincterotomy for Bile Duct Stones: A 17-Year Experience with 2,137 Cases.

BACKGROUND: Risk factors for post-endoscopic retrograde cholangiopancreatography (ERCP) complications are well-studied. However, risk factors for complications and success after endoscopic sphincterotomy (EST) for duct stones are poorly determined. This study aimed to verify risk factors for mortality, complications, and success after EST. METHODS: A multivariate analysis was carried out in a dataset of ERCPs performed during 17 years. RESULTS: A total of5,226 ERCPs were performed, of which 2,137 were in patients with bile duct stones (1,458 women and 679 men; mean age = 57 years) who underwent EST with attempted stone removal. There were 171 (8%) complications, with pancreatitis in 87 (4.1%), bleeding in 48 (2.2%), other complications in 36 (1.8%), and mortality of 0.6%. Successful stone(s) removal was obtained in 2,028 cases (94.9%). On multivariate analysis, mortality was associated with age >60 years (1 vs. 0.2%), cholangitis (4.3 vs. 0.3%), and EST-related complications (5.8 vs. 0.2%). Complications were associated with unsuccessful stone removal (13.4 vs. 7.5%) and difficult cannulation (13.9 vs. 5.4%). An unsuccessful EST was independently related to difficult cannulation (86.2 vs. 98.7%), precutting (79.4 vs. 96.4%), and complications (86.5 vs. 95.6%). CONCLUSIONS: Risk factors for complications after EST for stones are delayed bile duct cannulation and failed stone retrieval. Mortality is higher in older patients, those who presented with an EST-related complication, or those who presented initially with cholangitis. Difficult cannulation, EST-related complications, and precutting were associated with an unsuccessful procedure. In this series, outpatient EST with attempted stone retrieval was found to be as safe as performing the procedure in hospitalized patients.