Synergetic Physical Freezing and Chemical Pretreatment of Lignocellulosic Sugarcane Bagasse Followed by Enzymatic Hydrolysis

This study focuses on employing an eco-friendly pretreatment approach for lignocellulosic Sugarcane Bagasse (SCB) as a major problematic solid waste in Egypt, complying with the standard legislation as well. The applied technique depended on SCB physical fractionation via freezing, followed by chemical hydrolysis using alkaline hydrogen peroxide (AHP) and enzymatic hydrolysis. The changes occurred in macrostructure and the entire lignocellulosic compounds during the pretreatment stages were evaluated. Freezing fractionation resulted in relatively low glucose yield and saccharification ratio at -20°C for 2 h of 307.52 mg/gm native SCB and 48.5%, respectively, where no total reducing sugars (TRS) was obtained. Further AHP pretreatment was performed for the frozen-fractionated SCB at -20°C and 2 h with assistance of Box–Behnken Design response surface methodology (RSM). The investigated key parameters were H2O2 concentration (3, 5.5 and 8 %v/v), temperature (25, 42.5 and 60°C) and pretreatment duration (1, 3 and 5 h). The results revealed that the statistical modelling was able to predict the response of glucose yield and TRS production with R2 = 0.8221 and 0.8814, respectively. Applying the optimization tool of RSM, the optimum predicted values of glucose yield and TRS production were (886.51 mg/gm native SCB and 1.44 mg/mL), respectively; confirmed by the experimental analysis (898.5 mg/gm native SCB and 1.32 mg/mL), respectively. The coincided saccharification ratio was 97.5%. These results were obtained at H2O2 of 3 % (v/v), 56.93°C and 1 h which were 4.32 and 2.01 times higher than that obtained during the freezing pretreatment phase for glucose yield and saccharification ratio, respectively.

The proton pump inhibitor omeprazole does not promote Clostridioides difficile colonization in a murine model

Proton pump inhibitor (PPI) use has been associated with microbiota alterations and susceptibility to Clostridioides difficile infections (CDIs) in humans. We assessed how PPI treatment alters the fecal microbiota and whether treatment promotes CDIs in a mouse model. Mice receiving a PPI treatment were gavaged with 40 mg/kg of omeprazole during a 7-day pretreatment phase, the day of C. difficile challenge, and the following 9 days. We found that mice treated with omeprazole were not colonized by C. difficile. When omeprazole treatment was combined with a single clindamycin treatment, one cage of mice remained resistant to C. difficile colonization, while the other cage was colonized. Treating mice with only clindamycin followed by challenge resulted in C. difficile colonization. 16S rRNA gene sequencing analysis revealed that omeprazole had minimal impact on the structure of the murine microbiota throughout the 16 days of omeprazole exposure. These results suggest omeprazole treatment alone is not sufficient to disrupt microbiota resistance to C. difficile infection in mice that are normally resistant in the absence of antibiotic treatment.

Ultrasonic Alkaline Pretreatment of Biological Activated Sludge from Wastewater Treatment Plants

Ultrasonic treatment has become a modern method for removal of micropollutants and refractory compounds from water/wastewater and to improve biodegradation efficiency of biological activated sludge from wastewater treatment plants, in order to produce biogas. This paper is referring to the ultrasonic pretreatment of biological activated sludge, before anaerobic fermentation phase, to increase the amount of biogas generation. The pretreatment of biological sludge is based on two steps: alkaline digestion and ultrasonication. Ten minutes of alkaline condition (pH 9.5 - 10.5) followed by 10 minutes ultrasonication (20 kHz frequency) were the general operating condition of sludge pretreatment phase. Parallel tests (with and without ultrasonic pretreatment step) were performed in order to assess the effect of ultrasonic pretreatment on biogas generation. Ultrasonication in alkaline condition of biological sludge heave led to doubling the amount of biogas generated in anaerobic fermentation phase.

Three dimensional organotypic ex vivo culture of tissues from post-operated tumor samples: Strengths and limitations.

e23151 Background: Evolution of tumor occurs in two phases, pretreatment phase, and posttreatment phase.Tumorigenic history and path of tumorigenic evolution determine the response of tumor cells to antitumor drug and thus the outcome of treatment. Carcinomas from the same organ-site with similar genomic alterations in different patients may vary in their tumorigenic history and their diverse paths of tumorigenic evolution which cause them respond differently to the same antitumor drugs. Uniqueness of tumorigenic history and paths of tumorigenic evolution in individual patient makes it ideal to test drugs, N-of-1. Here we present our experience with 3D organotypic ex vivo culture of tumor tissue from post-operated tumor samples. Methods: Informed consent was obtained from patients ( NCT02470715). The investigation was approved by IRB of the Avera Cancer Institute and the Western IRB. Surgically resected tissue was obtained from patients with different tumors of different organ sites including ovarian, breast, lung, endometrium, and cervix at the Avera Cancer Institute, SF, SD. Tissues from patients were collected in two formats, paired samples (tumor and tumor-adjacent normal) and unpaired samples. Results: As extracellular matrix lost in cell cultures, provide important signals for cell survival, differentiation and drug resistance we have established a protocol to culture slices in the 3D format. We have established 3D slice cultures (3x3 mm) of tumor-derived tissues which can be maintained ex vivo for at least three days. Tumor cells / normal cells from different tumors/tumor-adjacent normal tissues from day zero (non-cultured) were used to compare day1, day2, and day3 cultures. At the end of the culture period, slices were embedded in paraffin for histological analysis following H&E staining as well as IHC-staining for proliferation index (Ki-67), cellular proliferation signals (pS6RP), apoptosis (activated caspase 3), or tumor angiogenesis (CD31). Ki67 staining was characteristically different in cultured normal and cultured tumor tissues. Conclusions: Here, we show that tumor-derived tissues survive in 3D Matrigel culture for a minimum of 6 hours and maximum up to 3 days. Clinical trial information: NCT02470715.

Colonic and Hepatic Modulation by Lipoic Acid and/or N-Acetylcysteine Supplementation in Mild Ulcerative Colitis Induced by Dextran Sodium Sulfate in Rats

Lipoic acid (LA) andN-acetylcysteine (NAC) are antioxidant and anti-inflammatory agents that have not yet been tested on mild ulcerative colitis (UC). This study aims to evaluate the action of LA and/or NAC, on oxidative stress and inflammation markers in colonic and hepatic rat tissues with mild UC, induced by dextran sodium sulfate (DSS) (2% w/v). LA and/or NAC (100 mg·kg·day−1, each) were given, once a day, in the diet, in a pretreatment phase (7 days) and during UC induction (5 days). Colitis induction was confirmed by histological and biochemical analyses (high performance liquid chromatography, spectrophotometry, and Multiplex®). A redox imbalance occurred before an immunological disruption in the colon. NAC led to a decrease in hydrogen peroxide (H2O2), malondialdehyde (MDA) levels, and myeloperoxidase activity. In the liver, DSS did not cause damage but treatments with both antioxidants were potentially harmful, with LA increasing MDA and LA + NAC increasing H2O2, tumor necrosis factor alpha, interferon gamma, and transaminases. In summary, NAC exhibited the highest colonic antioxidant and anti-inflammatory activity, while LA + NAC caused hepatic damage.

Novel Electrochemical Treatment of Spent Caustic from the Hydrocarbon Industry Using Ti/BDD

During the crude oil refining process, NaOH solutions are used to remove H2S, H2Saq, and sulfur compounds from different hydrocarbon streams. The residues obtained are called “spent caustics.” These residues can be mixed with those obtained in other processes, adding to its chemical composition naphthenic acids and phenolic compounds, resulting in one of the most dangerous industrial residues. In this study, the use of electrochemical technology (ET), using BDD with Ti as substrate (Ti/BDD), is evaluated in electrolysis of spent caustic mixtures, obtained through individual samples from different refineries. In this way, the Ti/BDD’s capability of carrying out the electrochemical destruction of spent caustics in an acidic medium is evaluated having as key process a chemical pretreatment phase. The potential production of•OHs, as the main reactive oxygen species electrogenerated over Ti/BDD surface, was evaluated in HCl and H2SO4through fluorescence spectroscopy, demonstrating the reaction medium’s influence on its production. The results show that the hydrocarbon industry spent caustics can be mineralized to CO2and water, driving the use of ET and of the Ti/BDD to solve a real problem, whose potential and negative impact on the environment and on human health is and has been the environmental agencies’ main focus.

Scaling in Polymer Tubes and Interpretation for Use in Solar Water Heating Systems

An experimental study of the growth of scale on copper, nylon 6,6, semiaromatic high temperature nylon, polypropylene, polybutylene, and Teflon tubes exposed to hard water is presented. Results provide qualitative information on the scaling of polymer tubes in nonisothermal, flowing conditions expected in heat exchangers and solar absorbers. The 89-cm-long tubes were placed in tube-in-shell heat exchangers. The tubes were exposed to flowing water for 1660 h, a 1120-h pretreatment phase using tap water adjusted to supersaturation of about 2 and pH of 8, followed by a 540-h acceleration phase using tap water with an adjusted total calcium concentration of 4×10−3M, and a pH of 9. Flow rate was 4 cm/s. A 50% propylene glycol solution at 60°C was maintained on the shell side of the heat exchanger. Sections of the tubes were removed periodically to determine the extent of scaling. Results include scanning electron microscope images of the tube surfaces before and after exposure to the flowing water, x-ray diffraction to determine the crystalline phase content of the observed deposits, and chemical analysis to estimate the mass of calcium carbonate per unit surface area. A model of the scaling process is presented to help interpret the data. The data show conclusively that polymer tubes are prone to scaling. With the exception of nylon 6,6, the scaling rate on the polymers is about the same as that on copper. The nylon 6,6 substrate appears to enhance scaling. The enhancement is attributed to hydrolysis of the substrate.

Mortality of Zooplankton and Invertebrate Larvae Exposed to Cyclonic Pre-Treatment and Ultraviolet Radiation

Experiments were carried out to determine the effect of an integrated ballast water treatment system on the mortality of zooplankton. This treatment system consists of 2 treatment stages: 1) the cyclonic pretreatment phase and: 2) the ultraviolet radiation phase. Various zooplankton species were exposed to the treatment system over a range of 6 ultraviolet dosages (UV-C). In general, both treatment phases exhibited significant effects on zooplankton mortality. The results revealed that clam, mussel, and oyster larvae exhibited statistically similar mortality thresholds ranging between 96% and 99% at the higher UV dosages. A significant difference was observed when comparing these results to the mortality thresholds of brine shrimp nauplii (77%) and a natural population of zooplankton (40%). These findings suggest that species grouped into similar taxa may exhibit similar mortality responses to ultraviolet radiation, while those taxa containing different structural tissues capable of different photoprotective properties may exhibit different mortality responses. In addition, time-dependent, post-treatment mortality observations varied according to the taxa present, demonstrating that biological assays should include time-dependent mortality estimates to accurately assess the efficiencies of ballast water treatment systems.