Effect of enzymatic pretreatment on the physical quality of plantain (Musa ssp., group AAB) employing airflow reversal drying.

PubMed

Rodríguez-Miranda, J; Martínez-Sánchez, C E; Hernández-Santos, B; Juárez-Barrientos, J M; Ventura-Báez, E G; Herman-Lara, E

2018-01-01

This work aimed to evaluate the effect of enzymatic pretreatment on the color and texture of plantain ( Musa ssp., group AAB) dried by airflow reversal drying. Plantain slices 1.0 cm thick were used. Pretreatment with two commercial enzymes, Pectinex Ultra SPL ( Aspergillus aculeatus ) and Pectinex 3XL ( Aspergillus niger ), was performed. Drying kinetics were determined with and without pretreatment at temperatures of 50, 65 and 80 °C using a fixed bed convective dryer. An air speed of 6 m/s, a bed height of 5 cm and either unidirectional flow or airflow reversal (every 15 min) were used for drying. Color and texture were analyzed, and consumer acceptance of the results of the best treatments was determined. Pretreatment with the enzyme A. niger and airflow reversal gave the best drying kinetics and showed the greatest reduction in drying time (59.0%) at 80 °C. The best hardness results were found at 80 °C with A. niger enzymatic pretreatment with both types of air flow. Brightness and hue angle showed that samples pretreated with enzymes and dried at 65 °C had a lighter yellow color compared to non-pretreated samples. Plantain samples enzymatically pretreated and dried at 65 and 80 °C were the most accepted by consumers. This kind of enzymatic pretreatment on plantain could allow the conservation of some physical properties and reduction of drying times relative to the current methodology.

Effect of pretreatment on rehydration, colour and nanoindentation properties of potato cylinders dried using a mixed-mode solar dryer.

PubMed

Dhalsamant, Kshanaprava; Tripathy, Punyadarshini P; Shrivastava, Shanker L

2017-08-01

Desirable quality estimation is an important consumer driver for wider acceptability of mixed-mode solar drying of potatoes in food industries. The aim of this study is to characterise rehydration, colour, texture, nanoindentaion and microstructure of dried potato samples and to establish the influence of pre-drying treatment on the above qualities. The water absorption capacity and rehydration ability of solar dried potato were significantly influenced by pretreatment followed by rehydration temperature and sample diameter. The redness index (a*) of pretreated dried samples was lower with simultaneous higher value of yellowness index (b*), chroma (C*) and hue angle (h*). Also, the average nanohardness (H) of pretreated samples increased significantly by 22.64% compared to that of untreated samples. The average reduced modulus (E r ) and Young's modulus (E s ) of dried potato samples were 1.865 GPa and 1.403 GPa, respectively. Moreover, creep displacement of 43.27 nm was traced in the untreated potato samples during a 20 s dwell time under a constant load of 200 µN in the nanoindentation test. Micrographs revealed more uniform pore spaces in pretreated samples. Pretreated, thinner potato samples achieved better quality dried products in terms of rehydration, colour, texture and nanohardness indices with significantly improved microstructure and creep resistance properties. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Enhancement of drying and rehydration characteristics of okra by ultrasound pre-treatment application

NASA Astrophysics Data System (ADS)

Tüfekçi, Senem; Özkal, Sami Gökhan

2017-07-01

Effect of ultrasound application prior to hot air drying on drying and rehydration kinetics, rehydration ratio and microstructure of okra slices were investigated. For this purpose, the selected parameters are ultrasound pre-treatment time (10, 20 and 30 min), ultrasound amplitude (55 and 100%) and the temperature of drying air (60 and 70 °C). 5 mm thick cylindrical shaped okra slices were used in the experiments. The samples were immersed in water and ultrasonic pre-treatments were done in water with ultrasonic probe connected to an ultrasonic generator with 20 kHz frequency. Pre-treated samples were dried in a tray drier with a 0.3 m/s air velocity. Ultrasound pre-treatment affected the drying rate of the okra slices significantly. Drying time of okra slices was decreased by the application of ultrasound pre-treatment. Modified Page model found to be the most suitable model for describing the drying characteristics of okra slices. Improvements in rehydration properties of the dried samples were observed due to the ultrasound pre-treatment. The influence of the ultrasound pre-treatment on microstructure was clearly observed through scanning electron microscopy images of the dried samples. As the amplitude of ultrasound increased the changes in structure of the okra tissue increased.

Post-treatment mechanical refining as a method to improve overall sugar recovery of steam pretreated hybrid poplar.

PubMed

Dou, Chang; Ewanick, Shannon; Bura, Renata; Gustafson, Rick

2016-05-01

This study investigates the effect of mechanical refining to improve the sugar yield from biomass processed under a wide range of steam pretreatment conditions. Hybrid poplar chips were steam pretreated using six different conditions with or without SO2. The resulting water insoluble fractions were subjected to mechanical refining. After refining, poplar pretreated at 205°C for 10min without SO2 obtained a 32% improvement in enzymatic hydrolysis and achieved similar overall monomeric sugar recovery (539kg/tonne) to samples pretreated with SO2. Refining did not improve hydrolyzability of samples pretreated at more severe conditions, nor did it improve the overall sugar recovery. By maximizing overall sugar recovery, refining could partially decouple the pretreatment from other unit operations, and enable the use of low temperature, non-sulfur pretreatment conditions. The study demonstrates the possibility of using post-treatment refining to accommodate potential pretreatment process upsets without sacrificing sugar yields. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of Biological Pretreatment of Rubberwood with White Rot Fungi for Enzymatic Hydrolysis

PubMed Central

Nazarpour, Forough; Abdullah, Dzulkefly Kuang; Abdullah, Norhafizah; Zamiri, Reza

2013-01-01

The effects of biological pretreatment on the rubberwood (Hevea brasiliensis), was evaluated after cultivation of white rot fungi Ceriporiopsis subvermispora, Trametes versicolor, and a mixed culture of C. subvermispora and T. versicolor. The analysis of chemical compositions indicated that C. subvermispora had greater selectivity for lignin degradation with the highest lignin and hemicellulose loss at 45.06% and 42.08%, respectively, and lowest cellulose loss (9.50%) after 90 days among the tested samples. X-ray analysis showed that pretreated samples had a higher crystallinity than untreated samples. The sample pretreated by C. subvermispora presented the highest crystallinity of all the samples which might be caused by the selective degradation of amorphous components. Fourier transform infrared (FT-IR) spectroscopy demonstrated that the content of lignin and hemicellulose decreased during the biological pretreatment process. A study on hydrolysis of rubberwood treated with C. subvermispora, T. versicolor, and mixed culture for 90 days resulted in an increased sugar yield of about 27.67%, 16.23%, and 14.20%, respectively, as compared with untreated rubberwood (2.88%). The results obtained demonstrate that rubberwood is a potential raw material for industrial applications and white rot fungus C. subevermispora provides an effective method for improving the enzymatic hydrolysis of rubberwood. PMID:28809260

Surface and ultrastructural characterization of raw and pretreated switchgrass.

PubMed

Donohoe, Bryon S; Vinzant, Todd B; Elander, Richard T; Pallapolu, Venkata Ramesh; Lee, Y Y; Garlock, Rebecca J; Balan, Venkatesh; Dale, Bruce E; Kim, Youngmi; Mosier, Nathan S; Ladisch, Michael R; Falls, Matthew; Holtzapple, Mark T; Sierra-Ramirez, Rocio; Shi, Jian; Ebrik, Mirvat A; Redmond, Tim; Yang, Bin; Wyman, Charles E; Hames, Bonnie; Thomas, Steve; Warner, Ryan E

2011-12-01

The US Department of Energy-funded Biomass Refining CAFI (Consortium for Applied Fundamentals and Innovation) project has developed leading pretreatment technologies for application to switchgrass and has evaluated their effectiveness in recovering sugars from the coupled operations of pretreatment and enzymatic hydrolysis. Key chemical and physical characteristics have been determined for pretreated switchgrass samples. Several analytical microscopy approaches utilizing instruments in the Biomass Surface Characterization Laboratory (BSCL) at the National Renewable Energy Laboratory (NREL) have been applied to untreated and CAFI-pretreated switchgrass samples. The results of this work have shown that each of the CAFI pretreatment approaches on switchgrass result in different structural impacts at the plant tissue, cellular, and cell wall levels. Some of these structural changes can be related to changes in chemical composition upon pretreatment. There are also apparently different structural mechanisms that are responsible for achieving the highest enzymatic hydrolysis sugar yields. Copyright © 2011. Published by Elsevier Ltd.

[DNA quantification of blood samples pre-treated with pyramidon].

PubMed

Zhu, Chuan-Hong; Zheng, Dao-Li; Ni, Rao-Zhi; Wang, Hai-Sheng; Ning, Ping; Fang, Hui; Liu, Yan

2014-06-01

To study DNA quantification and STR typing of samples pre-treated with pyramidon. The blood samples of ten unrelated individuals were anticoagulated in EDTA. The blood stains were made on the filter paper. The experimental groups were divided into six groups in accordance with the storage time, 30 min, 1 h, 3 h, 6 h, 12 h and 24h after pre-treated with pyramidon. DNA was extracted by three methods: magnetic bead-based extraction, QIAcube DNA purification method and Chelex-100 method. The quantification of DNA was made by fluorescent quantitative PCR. STR typing was detected by PCR-STR fluorescent technology. In the same DNA extraction method, the sample DNA decreased gradually with times after pre-treatment with pyramidon. In the same storage time, the DNA quantification in different extraction methods had significant differences. Sixteen loci DNA typing were detected in 90.56% of samples. Pyramidon pre-treatment could cause DNA degradation, but effective STR typing can be achieved within 24 h. The magnetic bead-based extraction is the best method for STR profiling and DNA extraction.

Detection of Soil Nitrogen Using Near Infrared Sensors Based on Soil Pretreatment and Algorithms

PubMed Central

Nie, Pengcheng; Dong, Tao; He, Yong; Qu, Fangfang

2017-01-01

Soil nitrogen content is one of the important growth nutrient parameters of crops. It is a prerequisite for scientific fertilization to accurately grasp soil nutrient information in precision agriculture. The information about nutrients such as nitrogen in the soil can be obtained quickly by using a near-infrared sensor. The data can be analyzed in the detection process, which is nondestructive and non-polluting. In order to investigate the effect of soil pretreatment on nitrogen content by near infrared sensor, 16 nitrogen concentrations were mixed with soil and the soil samples were divided into three groups with different pretreatment. The first group of soil samples with strict pretreatment were dried, ground, sieved and pressed. The second group of soil samples were dried and ground. The third group of soil samples were simply dried. Three linear different modeling methods are used to analyze the spectrum, including partial least squares (PLS), uninformative variable elimination (UVE), competitive adaptive reweighted algorithm (CARS). The model of nonlinear partial least squares which supports vector machine (LS-SVM) is also used to analyze the soil reflectance spectrum. The results show that the soil samples with strict pretreatment have the best accuracy in predicting nitrogen content by near-infrared sensor, and the pretreatment method is suitable for practical application. PMID:28492480

A sensitive chemiluminescence enzyme immunoassay based on molecularly imprinted polymers solid-phase extraction of parathion.

PubMed

Chen, Ge; Jin, Maojun; Du, Pengfei; Zhang, Chan; Cui, Xueyan; Zhang, Yudan; She, Yongxin; Shao, Hua; Jin, Fen; Wang, Shanshan; Zheng, Lufei; Wang, Jing

2017-08-01

The chemiluminescence enzyme immunoassay (CLEIA) method responds differently to various sample matrices because of the matrix effect. In this work, the CLEIA method was coupled with molecularly imprinted polymers (MIPs) synthesized by precipitation polymerization to study the matrix effect. The sample recoveries ranged from 72.62% to 121.89%, with a relative standard deviation (RSD) of 3.74-18.14%.The ratio of the sample matrix-matched standard curve slope rate to the solvent standard curve slope was 1.21, 1.12, 1.17, and 0.85 for apple, rice, orange and cabbage in samples pretreated with the mixture of PSA and C 18 . However, the ratio of sample (apple, rice, orange, and cabbage) matrix-matched standard-MIPs curve slope rate to the solvent standard curve was 1.05, 0.92, 1.09, and 1.05 in samples pretreated with MIPs, respectively. The results demonstrated that the matrices of the samples greatly interfered with the detection of parathion residues by CLEIA. The MIPs bound specifically to the parathion in the samples and eliminated the matrix interference effect. Therefore, the CLEIA method have successfully applied MIPs in sample pretreatment to eliminate matrix interference effects and provided a new sensitive assay for agro-products. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of pretreatment on the enzymatic hydrolysis of kitchen waste for xanthan production.

PubMed

Li, Panyu; Zeng, Yu; Xie, Yi; Li, Xiang; Kang, Yan; Wang, Yabo; Xie, Tonghui; Zhang, Yongkui

2017-01-01

The study was carried out to gain insight into the effect of pretreatment on enzymatic hydrolysis of kitchen waste (KW) for xanthan fermentation. Herein, various pretreatments were applied and it was found that chemical pretreatment had positive effect on the following enzymatic or overall hydrolysis process. The highest reducing sugar concentration was obtained as 51.87g/L from 2% HCl (90°C) pretreated sample, while the Kjeldahl nitrogen (KDN) concentration was 7.79g/L. Kinetic study showed that first order kinetic model was suitable to describe the enzymatic hydrolysis process. The obtained kitchen waste hydrolysate (KWH) was successfully applied for xanthan fermentation. Xanthan concentration reached 4.09-6.46g/L when KWH with 2% HCl (90°C) pretreatment was applied as medium. In comparison, a xanthan concentration of 3.25-5.57g/L was obtained from KWH without pretreatment. Therefore, pretreatment of KW using diluted acid is favorable for the overall hydrolysis process and effective for xanthan fermentation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ultrasound assisted biogas production from landfill leachate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oz, Nilgün Ayman, E-mail: nilgunayman@comu.edu.tr; Yarimtepe, Canan Can

Highlights: • Effect of low frequency ultrasound pretreatment on leachate was investigated. • Three different ultrasound energy inputs (200, 400 and 600 W/l) was applied. • Low-frequency ultrasound treatment increased soluble COD in landfill leachate. • Application of ultrasound to leachate increased biogas production about 40%. • Application of ultrasound to leachate increased total methane production rate about 20%. - Abstract: The aim of this study is to increase biogas production and methane yield from landfill leachate in anaerobic batch reactors by using low frequency ultrasound as a pretreatment step. In the first part of the study, optimum conditions formore » solubilization of organic matter in leachate samples were investigated using various sonication durations at an ultrasound frequency of 20 kHz. The level of organic matter solubilization during ultrasonic pretreatment experiments was determined by calculating the ratio of soluble chemical oxygen demand (sCOD) to total chemical oxygen demand (tCOD). The sCOD/tCOD ratio was increased from 47% in raw leachate to 63% after 45 min sonication at 600 W/l. Non-parametric Friedman’s test indicated that ultrasonic pretreatment has a significant effect on sCOD parameter for leachate (p < 0.05). In the second part of the study, anaerobic batch reactors were operated for both ultrasonically pretreated and untreated landfill leachate samples in order to assess the effect of sonication on biogas and methane production rate. In anaerobic batch reactor feed with ultrasonically pretreated leachate, 40% more biogas was obtained compared to the control reactor. For statistical analysis, Mann–Whitney U test was performed to compare biogas and methane production rates for raw and pretreated leachate samples and it has been found that ultrasonic pretreatment significantly enhanced biogas and methane production rates from leachate (p < 0.05) in anaerobic batch reactors. The overall results showed that low frequency ultrasound pretreatment can be potentially used for wastewater management especially with integration of anaerobic processes.« less

Acute d-amphetamine pretreatment does not alter stimulant self-administration in humans.

PubMed

Stoops, William W; Vansickel, Andrea R; Lile, Joshua A; Rush, Craig R

2007-05-01

Recent clinical research indicates that d-amphetamine is effective in treating cocaine and methamphetamine dependence. There is concern, however, with the use of d-amphetamine as a pharmacotherapy because acute administration of d-amphetamine decreases inhibition in cocaine-using individuals and may increase drug-taking behavior. The purpose of the present experiment was to determine whether acute d-amphetamine pretreatment would alter the reinforcing, subject-rated, and cardiovascular effects of d-amphetamine. To this end, 7 human volunteers first sampled doses of oral d-amphetamine (0, 8, and 16 mg). These doses engender moderate drug taking and were selected to avoid a ceiling or floor effect. Volunteers were then allowed to self-administer these sampled doses using a modified progressive-ratio procedure in two sessions in which they received pretreatment with either 0 or 15 mg oral d-amphetamine 2 h prior to completing the modified progressive-ratio procedure. d-Amphetamine produced prototypical stimulant-like effects (e.g., increased ratings of stimulated, elevated blood pressure) and maintained responding on the modified progressive-ratio schedule. Pretreatment with 15 mg oral d-amphetamine also produced prototypical stimulant-like effects, but failed to alter break points for d-amphetamine on the modified progressive-ratio procedure relative to placebo pretreatment. These results indicate that acute d-amphetamine pretreatment does not increase stimulant self-administration.

Effect of high carbon dioxide atmosphere packaging and soluble gas stabilization pre-treatment on the shelf-life and quality of chicken drumsticks.

PubMed

Al-Nehlawi, A; Saldo, J; Vega, L F; Guri, S

2013-05-01

The effects of an aerobic modified atmosphere packaging (MAP) (70% CO2, 15% O2 and 15% N2) with and without a CO2 3-h soluble gas stabilization (SGS) pre-treatment of chicken drumsticks were determined for various package and product quality characteristics. The CO2 dissolved into drumsticks was determined. The equilibrium between CO2 dissolved in drumsticks and CO2 in head space was reached within 48h after packaging, showing highest values of CO2 in SGS pre-treated samples. This greater availability of CO2 resulted in lower counts of TAB and Pseudomonas in SGS than in MAP drumsticks. Package collapse was significantly reduced in SGS samples. The average of CO2 dissolved in the MAP treatment was 567mg CO2kg(-1) of chicken and, 361mg CO2kg(-1) of chicken during the MAP treatment, in SGS pre-treated samples. This difference could be the quantity of CO2 dissolved during SGS pre-treatment. These results highlight the advantages of using SGS versus traditional MAP for chicken products preservation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fundamental characteristics of microwave explosion pretreatment of wood. I, Properties of temperature development

Treesearch

Xian-jun Li; Ke-yang Lu; Lan-ying Lin; Yong-dong Zhou; Zhi-yong Cai; Feng Fu

2010-01-01

In this study, the effects of microwave radiation intensity, radiation time and initial wood moisture content (MC) on the properties of temperature development in Eucalyptus urophylla wood samples during the microwave explosion pretreatment have been investigated using a new microwave pretreatment equipment. The results show that 1) with the increase of microwave...

Maleic acid treatment of biologically detoxified corn stover liquor.

PubMed

Kim, Daehwan; Ximenes, Eduardo A; Nichols, Nancy N; Cao, Guangli; Frazer, Sarah E; Ladisch, Michael R

2016-09-01

Elimination of microbial and enzyme inhibitors from pretreated lignocellulose is critical for effective cellulose conversion and yeast fermentation of liquid hot water (LHW) pretreated corn stover. In this study, xylan oligomers were hydrolyzed using either maleic acid or hemicellulases, and other soluble inhibitors were eliminated by biological detoxification. Corn stover at 20% (w/v) solids was LHW pretreated LHW (severity factor: 4.3). The 20% solids (w/v) pretreated corn stover derived liquor was recovered and biologically detoxified using the fungus Coniochaeta ligniaria NRRL30616. After maleic acid treatment, and using 5 filter paper units of cellulase/g glucan (8.3mg protein/g glucan), 73% higher cellulose conversion from corn stover was obtained for biodetoxified samples compared to undetoxified samples. This corresponded to 87% cellulose to glucose conversion. Ethanol production by yeast of pretreated corn stover solids hydrolysate was 1.4 times higher than undetoxified samples, with a reduction of 3h in the fermentation lag phase. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mobility of arsenic and its compounds in soil and soil solution: the effect of soil pretreatment and extraction methods.

PubMed

Száková, J; Tlustos, P; Goessler, W; Frková, Z; Najmanová, J

2009-12-30

The effect of soil extraction procedures and/or sample pretreatment (drying, freezing of the soil sample) on the extractability of arsenic and its compounds was tested. In the first part, five extraction procedures were compared with following order of extractable arsenic portions: 2M HNO(3)>0.43 M CH(3)COOH>or=0.05 M EDTA>or=Mehlich III (0.2M CH(3)COOH+0.25 M NH(4)NO(3)+0.013 M HNO(3)+0.015 M NH(4)F+0.001 M EDTA) extraction>water). Additionally, two methods of soil solution sampling were compared, centrifugation of saturated soil and the use of suction cups. The results showed that different sample pretreatments including soil solution sampling could lead to different absolute values of mobile arsenic content in soils. However, the interpretation of the data can lead to similar conclusions as apparent from the comparison of the soil solution sampling methods (r=0.79). For determination of arsenic compounds mild extraction procedures (0.05 M (NH(4))(2)SO(4), 0.01 M CaCl(2), and water) and soil solution sampling using suction cups were compared. Regarding the real soil conditions the extraction of fresh samples and/or in situ collection of soil solution are preferred among the sample pretreatments and/or soil extraction procedures. However, chemical stabilization of the solutions should be allowed and included in the analytical procedures for determination of individual arsenic compounds.

Hexavalent Chrome Free Coatings for Electronics: Electromagnetic Interference (EMI) Shielding Effectiveness (SE)

NASA Technical Reports Server (NTRS)

Kessel, Kurt R.

2016-01-01

Determine the suitability of trivalent chromium conversion coatings that meet the requirements of MIL-DTL-5541, Type II, for use in applications where high-frequency electrical performance is important. Evaluate the ability of hexavalent chrome free pretreated aluminum to form adequate EMI seals, and maintain that seal while being subjected to harsh environmental conditions. Assess the performance of trivalent chromium pretreatments against a known control hexavalent chrome pretreatment before and after they have been exposed to a set of environmental conditions. It is known that environmental testing causes a decrease in shielding effectiveness when hexavalent chrome pretreatments are used (Alodine 1200s). Need to determine how shielding effectiveness will be affected with the use of hexavalent chrome free pretreatments. Performance will be assessed by evaluating shielding effectiveness (SE) test data from a variety of test samples comprised of different aluminum types and/or conversion coatings. The formation of corrosion will be evaluated between the mating surfaces and gasket to assess the corrosion resistant properties of the pretreatments, comparing the hexavalent control to the hexavalent chrome free pretreatments.

Pretreatment of whole blood using hydrogen peroxide and UV irradiation. Design of the advanced oxidation process.

PubMed

Bragg, Stefanie A; Armstrong, Kristie C; Xue, Zi-Ling

2012-08-15

A new process to pretreat blood samples has been developed. This process combines the Advanced Oxidation Process (AOP) treatment (using H(2)O(2) and UV irradiation) with acid deactivation of the enzyme catalase in blood. A four-cell reactor has been designed and built in house. The effect of pH on the AOP process has been investigated. The kinetics of the pretreatment process shows that at high C(H(2)O(2),t=0), the reaction is zeroth order with respect to C(H(2)O(2)) and first order with respect to C(blood). The rate limiting process is photon flux from the UV lamp. Degradation of whole blood has been compared with that of pure hemoglobin samples. The AOP pretreatment of the blood samples has led to the subsequent determination of chromium and zinc concentrations in the samples using electrochemical methods. Copyright © 2012 Elsevier B.V. All rights reserved.

Elucidation of Factors Effecting Enzymatic Saccharification using Transgenic Hardwoods

NASA Astrophysics Data System (ADS)

Min, Douyong

Three groups of transgenic wood samples were used as starting materials to elucidate the recalcitrance of enzymatic saccharification with/without pretreatments. The first group of transgenic wood samples is low lignin P. trichocarpa. The second group is low xylan P. trichocarpa. The third one is 12 hybrid poplars which have different levels of S/V ratio and lignin content. Four pretreatments were carried out in this research including dilute sulfuric acid, green liquor, auto hydrolysis and ozone delignification. The behavior among pretreatments as a function of removal of lignin appears to be different. Lignin is the major factor of recalcitrance of the lignocellulosic material to ethanol conversion process. Xylan also plays key role in this process. In addition, the crude milled wood lignin was isolated from these three groups of transgenic samples. Lignin carbohydrate complexes was characterized by 1H-13C HMQC and 13C NMR. Thus the effect of LCCs on enzymatic saccharification was elucidated. High S/V ratio propels the lignin removal during pretreatments however; high S/V ratio retards the enzymatic saccharification on the lignocellulosic material without pretreatments. The level of LCCs linkages accounts for additional recalcitrance of the lignocellulosic material to ethanol conversion process. The amount of LCCs linkages is affected by xylan content, lignin content and S/V ratio.

Comparative AMS radiocarbon dating of pretreated versus non-pretreated tropical wood samples

NASA Astrophysics Data System (ADS)

Patrut, Adrian; von Reden, Karl F.; Lowy, Daniel A.; Mayne, Diana H.; Elder, Kathryn E.; Roberts, Mark L.; McNichol, Ann P.

2010-04-01

Several wood samples collected from Dorslandboom, a large iconic African baobab ( Adansonia digitata L.) from Namibia, were investigated by AMS radiocarbon dating subsequent to pretreatment and, alternatively, without pretreatment. The comparative statistical evaluation of results showed that there were no significant differences between fraction modern values and radiocarbon dates of the samples analyzed after pretreatment and without pretreatment, respectively. The radiocarbon date of the oldest sample was 993 ± 20 BP. Dating results also revealed that Dorslandboom is a multi-generation tree, with several stems showing different ages.

Comparative Study of the Effect of Sample Pretreatment and Extraction on the Determination of Flavonoids from Lemon (Citrus limon)

PubMed Central

Ledesma-Escobar, Carlos A.; Priego-Capote, Feliciano; Luque de Castro, María D.

2016-01-01

Background Flavonoids have shown to exert multiple beneficial effects on human health, being also appreciated by both food and pharmaceutical industries. Citrus fruits are a key source of flavonoids, thus promoting studies to obtain them. Characteristics of these studies are the discrepancies among sample pretreatments and among extraction methods, and also the scant number of comparative studies developed so far. Objective Evaluate the effect of both the sample pretreatment and the extraction method on the profile of flavonoids isolated from lemon. Results Extracts from fresh, lyophilized and air-dried samples obtained by shaking extraction (SE), ultrasound-assisted extraction (USAE), microwave-assisted extraction (MAE) and superheated liquid extraction (SHLE) were analyzed by LC–QTOF MS/MS, and 32 flavonoids were tentatively identified using MS/MS information. ANOVA applied to the data from fresh and dehydrated samples and from extraction by the different methods revealed that 26 and 32 flavonoids, respectively, were significant (p≤0.01). The pairwise comparison (Tukey HSD; p≤0.01) showed that lyophilized samples are more different from fresh samples than from air-dried samples; also, principal component analysis (PCA) showed a clear discrimination among sample pretreatment strategies and suggested that such differences are mainly created by the abundance of major flavonoids. On the other hand, pairwise comparison of extraction methods revealed that USAE and MAE provided quite similar extracts, being SHLE extracts different from the other two. In this case, PCA showed a clear discrimination among extraction methods, and their position in the scores plot suggests a lower abundance of flavonoids in the extracts from SHLE. In the two PCA the loadings plots revealed a trend to forming groups according to flavonoid aglycones. Conclusions The present study shows clear discrimination caused by both sample pretreatments and extraction methods. Under the studied conditions, liophilization provides extracts with higher amounts of flavonoids, and USAE is the best method for isolation of these compounds, followed by MAE and SE. On the contrary, the SHLE method was the less favorable to extract flavonoids from citrus owing to degradation. PMID:26807979

Progress in ethanol production from corn kernel by applying cooking pre-treatment.

PubMed

Voca, Neven; Varga, Boris; Kricka, Tajana; Curic, Duska; Jurisic, Vanja; Matin, Ana

2009-05-01

In order to improve technological properties of corn kernel for ethanol production, samples were treated with a hydrothermal pre-treatment of cooking (steaming), prior to drying. Two types of cooking process parameters were applied; steam pressure of 0.5 bars during a 10 min period, and steam pressure of 1.5 bars during a 30 min period. Afterwards, samples were dried at four different temperatures, 70, 90, 110 and 130 degrees C. Control sample was also submitted to the aforementioned drying parameters. Since the results showed that starch utilization, due to the gelatinization process, was considerably higher in the samples pre-treated before the ethanol production process, it was found that the cooking treatment had a positive effect on ethanol yield from corn kernel. Therefore, the highest ethanol yield was found in the corn kernel samples cooked for 30 min at steam pressure 1.5 bars and dried at 130 degrees C. Due to the similarity of processes used for starch fermentation, introduction of cooking pre-treatment will not significantly increase the overall ethanol production costs, whereas it will result in significantly higher ethanol yield.

Insights on the Effects of Heat Pretreatment, pH, and Calcium Salts on Isolation of Rare Actinobacteria from Karstic Caves

PubMed Central

Fang, Bao-Zhu; Salam, Nimaichand; Han, Ming-Xian; Jiao, Jian-Yu; Cheng, Juan; Wei, Da-Qiao; Xiao, Min; Li, Wen-Jun

2017-01-01

The phylum Actinobacteria is one of the most ubiquitously present bacterial lineages on Earth. In the present study, we try to explore the diversity of cultivable rare Actinobacteria in Sigangli Cave, Yunnan, China by utilizing a combination of different sample pretreatments and under different culture conditions. Pretreating the samples under different conditions of heat, setting the isolation condition at different pHs, and supplementation of media with different calcium salts were found to be effective for isolation of diverse rare Actinobacteria. During our study, a total of 204 isolates affiliated to 30 genera of phylum Actinobacteria were cultured. Besides the dominant Streptomyces, rare Actinobacteria of the genera Actinocorallia, Actinomadura, Agromyces, Alloactinosynnema, Amycolatopsis, Beutenbergia, Cellulosimicrobium, Gordonia, Isoptericola, Jiangella, Knoellia, Kocuria, Krasilnikoviella, Kribbella, Microbacterium, Micromonospora, Mumia, Mycobacterium, Nocardia, Nocardioides, Nocardiopsis, Nonomuraea, Oerskovia, Pseudokineococcus, Pseudonocardia, Rhodococcus, Saccharothrix, Streptosporangium, and Tsukamurella were isolated from these cave samples. PMID:28848538

Biochemical degradation and physical migration of polyphenolic compounds in osmotic dehydrated blueberries with pulsed electric field and thermal pretreatments.

PubMed

Yu, Yuanshan; Jin, Tony Z; Fan, Xuetong; Wu, Jijun

2018-01-15

Fresh blueberries were pretreated by pulsed electric fields (PEF) or thermal pretreatment and then were subject to osmotic dehydration. The changes in contents of anthocyanins, predominantly phenolic acids and flavonols, total phenolics, polyphenol oxidase (PPO) activity and antioxidant activity in the blueberry samples during pretreatment and osmotic dehydration were investigated. Biochemical degradation and physical migration of these nutritive compounds from fruits to osmotic solutions were observed during the pretreatments and osmotic dehydration. PEF pretreated samples had the least degradation loss but the most migration loss of these compounds compared to thermally pretreated and control samples. Higher rates of water loss and solid gain during osmotic dehydration were also obtained by PEF pretreatment, reducing the dehydration time from 130 to 48h. PEF pretreated and dehydrated fruits showed superior appearance to thermally pretreated and control samples. Therefore, PEF pretreatment is a preferred technology that balances nutritive quality, appearance, and dehydration rate. Published by Elsevier Ltd.

Effect of EDTA Conditioning and Carbodiimide Pretreatment on the Bonding Performance of All-in-One Self-Etch Adhesives

PubMed Central

Singh, Shipra; Nagpal, Rajni; Tyagi, Shashi Prabha; Manuja, Naveen

2015-01-01

Objective. This study evaluated the effect of ethylenediaminetetraacetic acid (EDTA) conditioning and carbodiimide (EDC) pretreatment on the shear bond strength of two all-in-one self-etch adhesives to dentin. Methods. Flat coronal dentin surfaces were prepared on one hundred and sixty extracted human molars. Teeth were randomly divided into eight groups according to two different self-etch adhesives used [G-Bond and OptiBond-All-In-One] and four different surface pretreatments: (a) adhesive applied following manufacturer's instructions; (b) dentin conditioning with 24% EDTA gel prior to application of adhesive; (c) EDC pretreatment followed by application of adhesive; (d) application of EDC on EDTA conditioned dentin surface followed by application of adhesive. Composite restorations were placed in all the samples. Ten samples from each group were subjected to immediate and delayed (6-month storage in artificial saliva) shear bond strength evaluation. Data collected was subjected to statistical analysis using three-way ANOVA and post hoc Tukey's test at a significance level of p < 0.05.  Results and Conclusion. EDTA preconditioning as well as EDC pretreatment alone had no significant effect on the immediate and delayed bond strengths of either of the adhesives. However, EDC pretreatment on EDTA conditioned dentin surface resulted in preservation of resin-dentin bond strength of both adhesives with no significant fall over six months. PMID:26557850

Treatment of olive mill wastewater by chemical processes: effect of acid cracking pretreatment.

PubMed

Hande Gursoy-Haksevenler, B; Arslan-Alaton, Idil

2014-01-01

The effect of acid cracking (pH 2.0; T 70 °C) and filtration as a pretreatment step on the chemical treatability of olive mill wastewater (chemical oxygen demand (COD) 150,000 m/L; total organic carbon (TOC) 36,000 mg/L; oil-grease 8,200 mg/L; total phenols 3,800 mg/L) was investigated. FeCl3 coagulation, Ca(OH)2 precipitation, electrocoagulation using stainless steel electrodes and the Fenton's reagent were applied as chemical treatment methods. Removal performances were examined in terms of COD, TOC, oil-grease, total phenols, colour, suspended solids and acute toxicity with the photobacterium Vibrio fischeri. Significant oil-grease (95%) and suspended solids (96%) accompanied with 58% COD, 43% TOC, 39% total phenols and 80% colour removals were obtained by acid cracking-filtration pretreatment. Among the investigated chemical treatment processes, electrocoagulation and the Fenton's reagent were found more effective after pretreatment, especially in terms of total phenols removal. Total phenols removal increased from 39 to 72% when pretreatment was applied, while no significant additional (≈10-15%) COD and TOC removals were obtained when acid cracking was coupled with chemical treatment. The acute toxicity of the original olive mill wastewater sample increased considerably after pretreatment from 75 to 89% (measured for the 10-fold diluted wastewater sample). An operating cost analysis was also performed for the selected chemical treatment processes.

Thermogravimetric study and kinetic analysis of fungal pretreated corn stover using the distributed activation energy model.

PubMed

Ma, Fuying; Zeng, Yelin; Wang, Jinjin; Yang, Yang; Yang, Xuewei; Zhang, Xiaoyu

2013-01-01

Non-isothermal thermogravimetry/derivative thermogravimetry (TG/DTG) measurements are used to determine pyrolytic characteristics and kinetics of lignocellulose. TG/DTG experiments at different heating rates with corn stover pretreated with monocultures of Irpex lacteus CD2 and Auricularia polytricha AP and their cocultures were conducted. Heating rates had little effect on the pyrolysis process, but the peak of weight loss rate in the DTG curves shifted towards higher temperature with heating rate. The maximum weight loss of biopretreated samples was 1.25-fold higher than that of the control at the three heating rates, and the maximum weight loss rate of the co-culture pretreated samples was intermediate between that of the two mono-cultures. The activation energies of the co-culture pretreated samples were 16-72 kJ mol(-1) lower than that of the mono-culture at the conversion rate range from 10% to 60%. This suggests that co-culture pretreatment can decrease activation energy and accelerate pyrolysis reaction thus reducing energy consumption. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of biological pretreatments in enhancing corn straw biogas production.

PubMed

Zhong, Weizhang; Zhang, Zhongzhi; Luo, Yijing; Sun, Shanshan; Qiao, Wei; Xiao, Meng

2011-12-01

A biological pretreatment with new complex microbial agents was used to pretreat corn straw at ambient temperature (about 20°C) to improve its biodegradability and anaerobic biogas production. A complex microbial agent dose of 0.01% (w/w) and pretreatment time of 15 days were appropriate for biological pretreatment. These treatment conditions resulted in 33.07% more total biogas yield, 75.57% more methane yield, and 34.6% shorter technical digestion time compared with the untreated sample. Analyses of chemical compositions showed 5.81-25.10% reductions in total lignin, cellulose, and hemicellulose contents, and 27.19-80.71% increases in hot-water extractives; these changes contributed to the enhancement of biogas production. Biological pretreatment could be an effective method for improving biodegradability and enhancing the highly efficient biological conversion of corn straw into bioenergy. Copyright © 2011 Elsevier Ltd. All rights reserved.

Exploring accessibility of pretreated poplar cell walls by measuring dynamics of fluorescent probes.

PubMed

Paës, Gabriel; Habrant, Anouck; Ossemond, Jordane; Chabbert, Brigitte

2017-01-01

The lignocellulosic cell wall network is resistant to enzymatic degradation due to the complex chemical and structural features. Pretreatments are thus commonly used to overcome natural recalcitrance of lignocellulose. Characterization of their impact on architecture requires combinatory approaches. However, the accessibility of the lignocellulosic cell walls still needs further insights to provide relevant information. Poplar specimens were pretreated using different conditions. Chemical, spectral, microscopic and immunolabeling analysis revealed that poplar cell walls were more altered by sodium chlorite-acetic acid and hydrothermal pretreatments but weakly modified by soaking in aqueous ammonium. In order to evaluate the accessibility of the pretreated poplar samples, two fluorescent probes (rhodamine B-isothiocyanate-dextrans of 20 and 70 kDa) were selected, and their mobility was measured by using the fluorescence recovery after photobleaching (FRAP) technique in a full factorial experiment. The mobility of the probes was dependent on the pretreatment type, the cell wall localization (secondary cell wall and cell corner middle lamella) and the probe size. Overall, combinatory analysis of pretreated poplar samples showed that even the partial removal of hemicellulose contributed to facilitate the accessibility to the fluorescent probes. On the contrary, nearly complete removal of lignin was detrimental to accessibility due to the possible cellulose-hemicellulose collapse. Evaluation of plant cell wall accessibility through FRAP measurement brings further insights into the impact of physicochemical pretreatments on lignocellulosic samples in combination with chemical and histochemical analysis. This technique thus represents a relevant approach to better understand the effect of pretreatments on lignocellulose architecture, while considering different limitations as non-specific interactions and enzyme efficiency.

Open sun drying of green bean: influence of pretreatments on drying kinetics, colour and rehydration capacity

NASA Astrophysics Data System (ADS)

İsmail, Osman; Kantürk Figen, Aysel; Pişkin, Sabriye

2017-04-01

Green bean ( Phaseolus Vulgaris L), classified under legume family, is a primary source of dietary protein in human diets especially in the agricultural countries. Green bean is susceptible to rapid deterioration because of their high moisture content and in order to prevent and present the green bean drying process is applied. In this study, effects of pretreatments on drying kinetics, colour and rehydration capacity of green bean were investigated. It was observed that the pretreatment affected the drying time. The shortest drying times were obtained from pretreated samples with blanched. Drying times were determined as 47, 41 and 29 h for natural, salted and blanch, respectively. The results showed that pretreatment and ambient temperature significantly ( P = 0.05) affected the drying rate and the drying time. The effective moisture diffusivity was determined by using Fick's second law and was found to be range between 3.15 × 10-10 and 1.2 × 10-10 m2/s for the pre-treated and natural green bean samples. The rehydration values were obtained 2.75, 2.71, 2.29 (g water/g dry matter) for the blanched, salted and natural samples. The effective diffusion coefficients were calculated using the data collected during the falling rate period and the experimental data are fitted to seven thin layer drying models which found in the literature. The Logarithmic model was found to best describe the drying behavior of fresh green beans under open air sun. Rehydration time and color parameters had been determined in order to improve the quality of dried green bean. Regarding with rehydration time and colour data, the best results were obtained at blanched drying conditions.

Effect of four pretreatments on enzymatic hydrolysis and ethanol fermentation of wheat straw. Influence of inhibitors and washing.

PubMed

Toquero, Cristina; Bolado, Silvia

2014-04-01

Pretreatment is essential in the production of alcohol from lignocellulosic material. In order to increase enzymatic sugar release and bioethanol production, thermal, dilute acid, dilute basic and alkaline peroxide pretreatments were applied to wheat straw. Compositional changes in pretreated solid fractions and sugars and possible inhibitory compounds released in liquid fractions were analysed. SEM analysis showed structural changes after pretreatments. Enzymatic hydrolysis and fermentation by Pichia stipitis of unwashed and washed samples from each pretreatment were performed so as to compare sugar and ethanol yields. The effect of the main inhibitors found in hydrolysates (formic acid, acetic acid, 5-hydroxymethylfurfural and furfural) was first studied through ethanol fermentations of model media and then compared to real hydrolysates. Hydrolysates of washed alkaline peroxide pretreated biomass provided the highest sugar concentrations, 31.82g/L glucose, and 13.75g/L xylose, their fermentation yielding promising results, with ethanol concentrations reaching 17.37g/L. Copyright © 2014 Elsevier Ltd. All rights reserved.

Complex effect of lignocellulosic biomass pretreatment with 1-butyl-3-methylimidazolium chloride ionic liquid on various aspects of ethanol and fumaric acid production by immobilized cells within SSF.

PubMed

Dotsenko, Anna S; Dotsenko, Gleb S; Senko, Olga V; Stepanov, Nikolay A; Lyagin, Ilya V; Efremenko, Elena N; Gusakov, Alexander V; Zorov, Ivan N; Rubtsova, Ekaterina A

2018-02-01

The pretreatment of softwood and hardwood samples (spruce and hornbeam wood) with 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) was undertaken for further simultaneous enzymatic saccharification of renewable non-food lignocellulosic biomass and microbial fermentation of obtained sugars to ethanol and fumaric acid. A multienzyme cocktail based on cellulases and yeast or fungus cells producing ethanol and fumaric acid were the main objects of [Bmim]Cl influence studies. A complex effect of lignocellulosic biomass pretreatment with [Bmim]Cl on various aspects of the process (both action of cellulases and microbial conversion of hydrolysates to target products) was revealed. Positive effects of the pretreatment with [Bmim]Cl included decreasing the lignin content in the biomass, and increasing the effectiveness of enzymatic hydrolysis and microbial transformation of pretreated biomass. Immobilized cells of both yeasts and fungi possessed improved productive characteristics in the biotransformation of biomass pretreated with [Bmim]Cl to ethanol and fumaric acid. Copyright © 2017 Elsevier Ltd. All rights reserved.

Improvement in shelf life of minimally processed cilantro leaves through integration of kinetin pretreatment and packaging interventions: Studies on microbial population dynamics, biochemical characteristics and flavour retention.

PubMed

Ranjitha, K; Shivashankara, K S; Sudhakar Rao, D V; Oberoi, Harinder Singh; Roy, T K; Bharathamma, H

2017-04-15

Effect of integrating optimized combination of pretreatment with packaging on shelf life of minimally processed cilantro leaves (MPCL) was appraised through analysis of their sensory attributes, biochemical characteristics, microbial population and flavour profile during storage. Minimally pretreated cilantro leaves pretreated with 50ppm kinetin and packed in 25μ polypropylene bags showed a shelf life of 21days. Optimized combination helped in efficiently maintaining sensory parameters, flavour profile, and retention of antioxidants in MPCL until 21days. Studies conducted on the effect of optimized combination on microbial population and flavour profile revealed that among different microorganisms, pectinolysers had a significant effect on spoilage of MPCL and their population of ⩽3.59logcfu/g was found to be acceptable. Principal component analysis of headspace volatiles revealed that (E)-2-undecenal, (E)-2-hexadecenal, (E)-2-tetradecenal & (E)-2-tetradecen-1-ol in stored samples clustered with fresh samples and therefore, could be considered as freshness indicators for MPCL. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of pre-treatment technologies on quantity and quality of source-sorted municipal organic waste for biogas recovery.

PubMed

Hansen, Trine Lund; Jansen, Jes la Cour; Davidsson, Asa; Christensen, Thomas Højlund

2007-01-01

Source-sorted municipal organic waste collected from different dwelling types in five Danish cities and pre-treated at three different plants was sampled and characterized several times during one year to investigate the origin of any differences in composition of the pre-treated waste introduced by city, pre-treatment technology, dwelling type or annual season. The investigated pre-treatment technologies were screw press, disc screen and shredder+magnet. The average quantity of pre-treated organic waste (biomass) produced from the incoming waste varied between the investigated pre-treatment technologies: 59%, 66% and 98% wet weight, respectively (41%, 34% and 2% reject, respectively). The pre-treatment technologies showed differences with respect to distribution of the chemical components in the waste between the biomass and the rejected material (reject), especially for dry matter, ash, collection bag material (plastic or paper) and easily degradable organic matter. Furthermore, the particle size of the biomass was related to the pre-treatment technology. The content of plastic in the biomass depended both on the actual collection bag material used in the system and the pre-treatment technology. The sampled reject consisted mostly of organic matter. For cities using plastic bags for the source-separated organic waste, the expected content of plastic in the reject was up to 10% wet weight (in some cases up to 20%). Batch tests for methane potential of the biomass samples showed only minor variations caused by the factors city, pre-treatment technology, dwelling type and season when based on the VS content of the waste (overall average 459STPm(3)/tVS). The amount of methane generated from 1t of collected waste was therefore mainly determined by the efficiency of the chosen pre-treatment technology described by the mass distribution of the incoming waste between biomass and reject.

Improving the conversion of biomass in catalytic fast pyrolysis via white-rot fungal pretreatment.

PubMed

Yu, Yanqing; Zeng, Yelin; Zuo, Jiane; Ma, Fuying; Yang, Xuewei; Zhang, Xiaoyu; Wang, Yujue

2013-04-01

This study investigated the effect of white-rot fungal pretreatment on corn stover conversion in catalytic fast pyrolysis (CFP). Corn stover pretreated by white-rot fungus Irpex lacteus CD2 was fast pyrolyzed alone (non-CFP) and with ZSM-5 zeolite (CFP) in a semi-batch pyroprobe reactor. The fungal pretreatment considerably increased the volatile product yields (predominantly oxygenated compounds) in non-CFP, indicating that fungal pretreatment enhances the corn stover conversion in fast pyrolysis. In the presence of ZSM-5 zeolite, these oxygenated volatiles were further catalytically converted to aromatic hydrocarbons, whose yield increased from 10.03 wt.% for the untreated corn stover to 11.49 wt.% for the pretreated sample. In contrast, the coke yield decreased from 14.29 to 11.93 wt.% in CFP following the fungal pretreatment. These results indicate that fungal pretreatment can enhance the production of valuable aromatics and decrease the amount of undesired coke, and thus has a beneficial effect on biomass conversion in CFP. Copyright © 2013 Elsevier Ltd. All rights reserved.

Experimental investigation of ionic liquid pretreatment of sugarcane bagasse with 1,3-dimethylimadazolium dimethyl phosphate.

PubMed

Bahrani, Samaneh; Raeissi, Sona; Sarshar, Mohammad

2015-06-01

In this study, an imidazolium-based ionic liquid (IL), 1,3-dimethylimidazolium dimethyl phosphate ([Mmim][DMP]), was applied for pretreating sugarcane bagasse to produce bioethanol. The main goal of this study was to investigate the feasibility of bagasse pretreatment with this IL, and to verify the effect of different operational parameters on the pretreatment process. Results indicated that temperature and duration of IL-pretreatment have optimum values. Within the range investigated, a maximum fermentable sugar conversion of 70.38% was achieved with this IL at 120°C and 120min. The corresponding value was 28.65% for the untreated biomass. The main cause for the observed enhancement in enzymatic hydrolysis was the reduction of cellulose crystallinity in the IL-pretreated biomass, as compared to the untreated sample, because it resulted in higher accessibility of the enzymes to the biomass after pretreatment. Moreover, the results indicated that aqueous [Mmim][DMP] mixtures are not as effective for pretreatment as the pure IL. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of combined pretreatments on color parameters during convective drying of Mirabelle plum ( Prunus domestica subsp. syriaca)

NASA Astrophysics Data System (ADS)

Dehghannya, Jalal; Gorbani, Rasoul; Ghanbarzadeh, Babak

2017-07-01

Discoloration and browning are caused primarily by various reactions, including Maillard condensation of hexoses and amino components, phenol polymerization and pigment destruction. Convective drying can be combined with various pretreatments to help reduce undesired color changes and improve color parameters of dried products. In this study, effects of ultrasound-assisted osmotic dehydration as a pretreatment before convective drying on color parameters of Mirabelle plum were investigated. Variations of L* (lightness), a* (redness/greenness), b* (yellowness/blueness), total color change (ΔE), chroma, hue angle and browning index values were presented versus drying time during convective drying of control and pretreated Mirabelle plums as influenced by ultrasonication time, osmotic solution concentration and immersion time in osmotic solution. Samples pretreated with ultrasound for 30 min and osmotic solution concentration of 70% had a more desirable color among all other pretreated samples, with the closest L*, a* and b* values to the fresh one, showing that ultrasound and osmotic dehydration are beneficial to the color of final products after drying.

A pretreatment method for HPLC analysis of cypermethrin in microbial degradation systems.

PubMed

Liu, Shuliang; Yao, Kai; Jia, Dongying; Zhao, Nan; Lai, Wen; Yuan, Huaiyu

2012-07-01

In this paper, a pretreatment method for high-performance liquid chromatography (HPLC) determination of cypermethrin (CY) in microbial degradation systems was systemically studied, primarily to solve the problem of inaccurate determination of CY concentration caused by its uneven distribution in the systems. A suitable pretreatment method was established, including sampling, extraction and dehydration of CY. Partial sampling could be taken for bacterial and yeast systems in which CY was uniformly dispersed by an emulsifying agent, while total sampling was only suitable for mold systems with or without an emulsifying agent. CY could be fully extracted from the samples in which microbial cells were disrupted by ultrasonic treatment with acetonitrile under ultrasonic condition. The extract could be effectively dehydrated and purified by passing it through an anhydrous Na(2)SO(4) column followed by an elution with acetonitrile. The determination of CY in the pretreated sample by HPLC showed a high precision [relative standard deviation (RSD) = 1.14%, n = 5] and a good stability over a period of five days (RSD = 1.57%, n = 5). The recoveries of CY in microbial degradation systems at three different spiked levels ranged from 95.68 to 108.09% (RSD = 0.50-5.87%, n = 5).

Lime pretreatment of lignocellulosic biomass

NASA Astrophysics Data System (ADS)

Chang, Shushien

Lignocellulose is a valuable alternative energy source. The susceptibility of lignocellulosic biomass to enzymatic hydrolysis is constrained due to its structural features, so pretreatment is essential to enhance enzymatic digestibility. Of the chemicals used as pretreatment agents, it has been reported that alkalis improve biomass digestibility significantly. In comparison with other alkalis such as NaOH and ammonia, lime (calcium hydroxide) has many advantages; it is very inexpensive, is safe, and can be recovered by carbonating wash water. The effects of lime pretreatment were explored on switchgrass and poplar wood, representing herbaceous and woody biomass, respectively. The effects of pretreatment conditions (time, temperature, lime loading, water loading, particle size, and oxygen pressure) have been systematically studies. Lime alone enhances the digestibility of switchgrass significantly; under the recommended conditions, the 3-d total sugar (glucose + xylose) yields of lime-treated switchgrass were 7 times that of untreated sample. When treating poplar wood, lime must be combined with oxygen to achieve high digestibility; oxidative lime pretreatment increased the 3-d total sugar yield of poplar wood to 12 times that of untreated sample. In a fundamental study, to determine why lime pretreatment is effective, the effects of three structural features on enzymatic digestibility were studied: lignin content, acetyl content, and crystallinity index (CrI). Poplar wood was treated with peracetic acid, potassium hydroxide, and ball milling to produce model lignocelluloses with a broad spectrum of lignin contents, acetyl contents, and CrI, respectively. Enzymatic hydrolysis was performed on the model lignocelluloses to determine the digestibility. Correlations between lignin/carbohydrate ratio, acetyl/carbohydrate ratio, CrI and digestibility were developed. The 95% prediction intervals show that the correlations predict the 1-h and 3-d total sugar conversions of a biomass sample within a precision of 5% and 20%, respectively. The digestibility of a variety of lime-treated biomass and ball-milled alpha-cellulose was compared to the correlations determined from the model compounds. The agreement between the measured and predicted values shows that the correlations are satisfactory and the three structural features---lignin content, acetyl content, and CrI---are the major factors that determine enzymatic digestibility.

Evaluation energy efficiency of bioconversion knot rejects to ethanol in comparison to other thermochemically pretreated biomass.

PubMed

Wang, Zhaojiang; Qin, Menghua; Zhu, J Y; Tian, Guoyu; Li, Zongquan

2013-02-01

Rejects from sulfite pulp mill that otherwise would be disposed of by incineration were converted to ethanol by a combined physical-biological process that was comprised of physical refining and simultaneous saccharification and fermentation (SSF). The energy efficiency was evaluated with comparison to thermochemically pretreated biomass, such as those pretreated by dilute acid (DA) and sulfite pretreatment to overcome recalcitrance of lignocelluloses (SPORL). It was observed that the structure deconstruction of rejects by physical refining was indispensable to effective bioconversion but more energy intensive than that of thermochemically pretreated biomass. Fortunately, the energy consumption was compensated by the reduced enzyme dosage and the elevated ethanol yield. Furthermore, adjustment of disk-plates gap led to reduction in energy consumption with negligible influence on ethanol yield. In this context, energy efficiency up to 717.7% was achieved for rejects, much higher than that of SPORL sample (283.7%) and DA sample (152.8%). Copyright © 2012 Elsevier Ltd. All rights reserved.

Understanding Treatment Readiness in Recently Assessed, Pre-Treatment Substance Abusers

PubMed Central

Rapp, Richard C.; Xu, Jiangmin; Carr, Carey A.; Timothy Lane, D.; Redko, Cristina; Wang, Jichuan; Carlson, Robert G.

2007-01-01

The goal of this study was to more fully understand readiness for treatment in a pre-treatment sample of 446 substance abusers. Structural Equation Modeling (SEM) was used to: (1) examine the relationships between readiness factors identified in the Pre-Treatment Readiness Scale; and (2) identify the effects of predisposing, illness, and inhibiting determinants on the factors. As with in-treatment samples, Problem Recognition was found to influence Treatment Readiness, although through a different intervening factor, Desire for Change rather than Desire for Help. A fourth factor, Treatment Reluctance, was also influenced by the Desire for Change factor. Fixed characteristics such as age and gender had minimal influences on readiness factors, as did inhibiting characteristics that reflected recent functioning. Illness characteristics including drug severity and perceived treatment barriers had a more robust influence on readiness factors. This study provides an increased understanding of readiness for treatment among pre-treatment substance abusers and also supported the construct validity of the Pre-Treatment Readiness Scale. PMID:19274847

Effects of water washing and torrefaction pretreatments on rice husk pyrolysis by microwave heating.

PubMed

Zhang, Shuping; Dong, Qing; Zhang, Li; Xiong, Yuanquan; Liu, Xinzhi; Zhu, Shuguang

2015-10-01

The influences of water washing, torrefaction and combined water washing-torrefaction pretreatments on microwave pyrolysis of rice husk samples were investigated. The results indicated that the process of combined water washing-torrefaction pretreatment could effectively remove a large portion of inorganics and improve the fuel characteristics to a certain extent. The gas products were rich in combustible compositions and the syngas quality was improved by pretreatment process. The liquid products contained less moisture content, acids and furans, while more concentrated phenols and sugars from microwave pyrolysis of rice husk after pretreatments, especially after the combined water washing-torrefaction pretreatment. Biochar, produced in high yield, has the alkaline pH (pH 8.2-10.0) and high surface area (S(BET) 157.81-267.84 m(2)/g), they have the potential to be used as soil amendments. It is noteworthy that water washing increased the pore surface area of biochar, but torrefaction reduced the pore surface area. Copyright © 2015 Elsevier Ltd. All rights reserved.

Microwave-assisted acid pretreatment of alkali lignin: Effect on characteristics and pyrolysis behavior.

PubMed

Duan, Dengle; Ruan, Roger; Wang, Yunpu; Liu, Yuhuan; Dai, Leilei; Zhao, Yunfeng; Zhou, Yue; Wu, Qiuhao

2018-03-01

This study performed microwave-assisted acid pretreatment on pure lignin. The effects of microwave temperature, microwave time, and hydrochloric acid concentration on characteristics and pyrolysis behavior of lignin were examined. Results of ultimate analysis revealed better properties of all pretreated samples than those of raw lignin. Fourier transform infrared spectroscopy analysis showed breakage of βO4 bond and aliphatic side chain, decrease in OH groups, and formation of CO groups in pretreatment. Microwave temperature exerted more significant influence on lignin structure. Thermal stability of treated lignin was improved and insensitive to short microwave time and acid concentration under mild conditions. Resulting from improved alkyl-phenols and decreased alkoxy-phenols, microwave-assisted acid pretreatment of lignin yielded bio-oil with excellent quality. Total yield of phenols in pyrolysis vapors (200 °C) improved to 14.15%, whereas that of guaiacols decreased to 22.36%. This study shows that microwave-assisted acid pretreatment is a promising technology for lignin conversion. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of aerobic pre-treatment on hydrogen and methane production in a two-stage anaerobic digestion process using food waste with different compositions.

PubMed

Rafieenia, Razieh; Girotto, Francesca; Peng, Wei; Cossu, Raffaello; Pivato, Alberto; Raga, Roberto; Lavagnolo, Maria Cristina

2017-01-01

Aerobic pre-treatment was applied prior to two-stage anaerobic digestion process. Three different food wastes samples, namely carbohydrate rich, protein rich and lipid rich, were prepared as substrates. Effect of aerobic pre-treatment on hydrogen and methane production was studied. Pre-aeration of substrates showed no positive impact on hydrogen production in the first stage. All three categories of pre-aerated food wastes produced less hydrogen compared to samples without pre-aeration. In the second stage, methane production increased for aerated protein rich and carbohydrate rich samples. In addition, the lag phase for carbohydrate rich substrate was shorter for aerated samples. Aerated protein rich substrate yielded the best results among substrates for methane production, with a cumulative production of approximately 351ml/gVS. With regard to non-aerated substrates, lipid rich was the best substrate for CH 4 production (263ml/gVS). Pre-aerated P substrate was the best in terms of total energy generation which amounted to 9.64kJ/gVS. This study revealed aerobic pre-treatment to be a promising option for use in achieving enhanced substrate conversion efficiencies and CH 4 production in a two-stage AD process, particularly when the substrate contains high amounts of proteins. Copyright © 2016 Elsevier Ltd. All rights reserved.

Surface analysis of graphite fiber reinforced polyimide composites

NASA Technical Reports Server (NTRS)

Messick, D. L.; Progar, D. J.; Wightman, J. P.

1983-01-01

Several techniques have been used to establish the effect of different surface pretreatments on graphite-polyimide composites. Composites were prepared from Celion 6000 graphite fibers and the polyimide LARC-160. Pretreatments included mechanical abrasion, chemical etching and light irradiation. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used in the analysis. Contact angle of five different liquids of varying surface tensions were measured on the composites. SEM results showed polymer-rich peaks and polymer-poor valleys conforming to the pattern of the release cloth used durng fabrication. Mechanically treated and light irradiated samples showed varying degrees of polymer peak removal, with some degradation down to the graphite fibers. Minimal changes in surface topography were observed on concentrations of surface fluorine even after pretreatment. The light irradiation pretreatment was most effective at reducing surface fluorine concentrations whereas chemical pretreatment was the least effective. Critical surface tensions correlated directly with the surface fluorine to carbon ratios as calculated from XPS.

The effect of alkaline pretreatment methods on cellulose structure and accessibility

DOE PAGES

Bali, Garima; Meng, Xianzhi; Deneff, Jacob I.; ...

2014-11-24

The effects of different alkaline pretreatments on cellulose structural features and accessibility are compared and correlated with the enzymatic hydrolysis of Populus. The pretreatments are shown to modify polysaccharides and lignin content to enhance the accessibility for cellulase enzymes. The highest increase in the cellulose accessibility was observed in dilute sodium hydroxide, followed by methods using ammonia soaking and lime (Ca(OH) 2). The biggest increase of cellulose accessibility occurs during the first 10 min of pretreatment, with further increases at a slower rate as severity increases. Low temperature ammonia soaking at longer residence times dissolved a major portion of hemicellulosemore » and exhibited higher cellulose accessibility than high temperature soaking. Moreover, the most significant reduction of degree of polymerization (DP) occurred for dilute sodium hydroxide (NaOH) and ammonia pretreated Populus samples. The study thus identifies important cellulose structural features and relevant parameters related to biomass recalcitrance.« less

Influence of physicochemical treatments on iron-based spent catalyst for catalytic oxidation of toluene.

PubMed

Kim, Sang Chai; Shim, Wang Geun

2008-06-15

The catalytic oxidation of toluene was studied over an iron-based spent and regenerated catalysts. Air, hydrogen, or four different acid solutions (oxalic acid (C2H2O4), citric acid (C6H8O7), acetic acid (CH3COOH), and nitric acid (HNO3)) were employed to regenerate the spent catalyst. The properties of pretreated spent catalyst were characterized by the Brunauer Emmett Teller (BET), inductively coupled plasma (ICP), temperature programmed reduction (TPR), and X-ray diffraction (XRD) analyses. The air pretreatment significantly enhanced the catalytic activity of the spent catalyst in the pretreatment temperature range of 200-400 degrees C, but its catalytic activity diminished at the pretreatment temperature of 600 degrees C. The catalytic activity sequence with respect to the air pretreatment temperatures was 400 degrees C>200 degrees C>parent>600 degrees C. The TPR results indicated that the catalytic activity was correlated with both the oxygen mobility and the amount of available oxygen on the catalyst. In contrast, the hydrogen pretreatment had a negative effect on the catalytic activity, and toluene conversion decreased with increasing pretreatment temperatures (200-600 degrees C). The XRD and TPR results confirmed the formation of metallic iron which had a negative effect on the catalytic activity with increasing pretreatment temperature. The acid pretreatment improved the catalytic activity of the spent catalyst. The catalytic activity sequence with respect to different acids pretreatment was found to be oxalic acid>citric acid>acetic acid>or=nitric acid>parent. The TPR results of acid pretreated samples showed an increased amount of available oxygen which gave a positive effect on the catalytic activity. Accordingly, air or acid pretreatments were more promising methods of regenerating the iron-based spent catalyst. In particular, the oxalic acid pretreatment was found to be most effective in the formation of FeC2O4 species which contributed highly to the catalytic combustion of toluene.

Effect of dentin biomodifiers on the immediate and long-term bond strengths of a simplified etch and rinse adhesive to dentin.

PubMed

Singh, Payal; Nagpal, Rajni; Singh, Udai Pratap

2017-08-01

This in vitro study evaluated the effect of dentin biomodifiers on the immediate and long-term bond strengths of a simplified etch and rinse adhesive to dentin. Flat coronal dentin surfaces were prepared in 120 extracted human molars. Teeth were randomly divided into 5 groups ( n = 24) according to 5 different surface pre-treatments: No pre-treatment (control); 1M carbodiimide (EDC); 0.1% epigallocatechin-3-gallate (EGCG); 2% minocycline (MI); 10% sodium ascorbate (SA). After surface pre-treatment, adhesive (Adper Single Bond 2 [SB], 3M ESPE) was applied. Composite was applied into transparent plastic tubes (2.5 mm in diameter), which was placed over the bonded dentin surface. From each group, 10 samples were subjected to shear bond strength (SBS) evaluation at 24 hours (immediate) and remaining 10 samples were tested after 6 months (delayed). Additionally, 4 samples per group were subjected to scanning electron microscopic analysis for observation of resin-dentin interface. The data were statistically analysed with Shaperio‑Wilk W test, 2-way analysis of variance (ANOVA), and post hoc Tukey's test. At 24 hours, SBS of all surface pre-treatment groups were comparable with the control group, with significant differences found between EDC and SA groups only ( p = 0.009). After 6 months storage, EDC, EGCG, and MI pre-treatments preserved the resin-dentin bond strength with no significant fall. Dentin pre-treatment with all the dentin biomodifiers except SA resulted in significant preservation of resin-dentin bond over 6 months storage period, without negatively affecting the immediate bond strength of the etch and rinse adhesive tested.

Organic acid pretreatment of oil palm trunk: effect on enzymatic saccharification and ethanol production.

PubMed

Rattanaporn, Kittipong; Tantayotai, Prapakorn; Phusantisampan, Theerawut; Pornwongthong, Peerapong; Sriariyanun, Malinee

2018-04-01

Effective lignocellulosic biomass saccharification is one of the crucial requirements of biofuel production via fermentation process. Organic acid pretreatments have been gained much interests as one of the high potential methods for promoting enzymatic saccharification of lignocellulosic materials due to their lower hazardous properties and lower production of inhibitory by-products of fermentation than typical chemical pretreatment methods. In this study, three organic acids, including acetic acid, oxalic acid, and citric acid, were examined for improvement of enzymatic saccharification and bioethanol production from oil palm trunk biomass. Based on response surface methodology, oxalic acid pretreated biomass released the maximum reducing sugar of 144 mg/g-pretreated biomass at the optimum condition, which was higher than untreated samples for 2.30 times. The released sugar yield of oil palm trunk also corresponded to the results of FT-IR analysis, which revealed the physical modification of cellulose and hemicellulose surface structures of pretreated biomass. Nevertheless, citric acid pretreatment is the most efficient pretreatment method to improve bioethanol fermentation of Saccharomyces cerevisiae TISTR 5606 at 1.94 times higher than untreated biomass. These results highlighted the selection of organic acid pretreatment as a potential method for biofuel production from oil palm trunk feedstocks.

Spectroscopic analysis of hot-water- and dilute-acid-extracted hardwood and softwood chips

NASA Astrophysics Data System (ADS)

Lehto, Joni; Louhelainen, Jarmo; Huttunen, Marko; Alén, Raimo

2017-09-01

Hot-water and dilute sulfuric acid pretreatments were performed prior to chemical pulping for silver/white birch (Betula pendula/B. pubescens) and Scots pine (Pinus sylvestris) chips to determine if varying pretreatment conditions on the original wood material were detectable via attenuated total reflectance (ATR) infrared spectroscopy. Pretreatment conditions varied with respect to temperature (130 °C and 150 °C) and treatment time (from 30 min to 120 min). The effects of the pretreatments on the composition of wood chips were determined by ATR infrared spectroscopy. The spectral data were compared to those determined by common wood chemistry analyses to evaluate the suitability of ATR spectroscopy method for rapid detection of changes in the wood chemical composition caused by different pretreatment conditions. In addition to determining wood species-dependent differences in the wood chemical composition, analytical results indicated that most essential lignin- and carbohydrates-related phenomena taking place during hot-water and acidic pretreatments could be described by applying this simple spectral method requiring only a small sample amount and sample preparation. Such information included, for example, the cleavage of essential lignin bonds (i.e., mainly β-O-4 linkages in guaiacyl and syringyl lignin) and formation of newly condensed lignin structures under different pretreatment conditions. Carbohydrate analyses indicated significant removal of hemicelluloses (especially hardwood xylan) and hemicelluloses-derived acetyl groups during the pretreatments, but they also confirmed the highly resistant nature of cellulose towards mild pretreatments.

Spectroscopic analysis of hot-water- and dilute-acid-extracted hardwood and softwood chips.

PubMed

Lehto, Joni; Louhelainen, Jarmo; Huttunen, Marko; Alén, Raimo

2017-09-05

Hot-water and dilute sulfuric acid pretreatments were performed prior to chemical pulping for silver/white birch (Betula pendula/B. pubescens) and Scots pine (Pinus sylvestris) chips to determine if varying pretreatment conditions on the original wood material were detectable via attenuated total reflectance (ATR) infrared spectroscopy. Pretreatment conditions varied with respect to temperature (130°C and 150°C) and treatment time (from 30min to 120min). The effects of the pretreatments on the composition of wood chips were determined by ATR infrared spectroscopy. The spectral data were compared to those determined by common wood chemistry analyses to evaluate the suitability of ATR spectroscopy method for rapid detection of changes in the wood chemical composition caused by different pretreatment conditions. In addition to determining wood species-dependent differences in the wood chemical composition, analytical results indicated that most essential lignin- and carbohydrates-related phenomena taking place during hot-water and acidic pretreatments could be described by applying this simple spectral method requiring only a small sample amount and sample preparation. Such information included, for example, the cleavage of essential lignin bonds (i.e., mainly β-O-4 linkages in guaiacyl and syringyl lignin) and formation of newly condensed lignin structures under different pretreatment conditions. Carbohydrate analyses indicated significant removal of hemicelluloses (especially hardwood xylan) and hemicelluloses-derived acetyl groups during the pretreatments, but they also confirmed the highly resistant nature of cellulose towards mild pretreatments. Copyright © 2017 Elsevier B.V. All rights reserved.

Biodegradation of organic matters from mixed unshredded municipal solid waste through air convection before landfilling.

PubMed

Mahar, Rasool B; Liu, Jianguo; Yue, Dongbei; Nie, Yongfeng

2007-01-01

Landfilling is a dominant municipal solid waste (MSW) disposal method in most developing countries. In China, approximately 85% of the generated MSW is being disposed of in the landfills. The amount of MSW is growing rapidly with the rate of approximately 8-10% annually, which contains a high quantity of moisture and organic matters. The problems of leachate treatment and landfill gas (LFG) emissions are increasing gradually. Reducing the hazard before emplacement, pretreatment of MSW before landfilling has become very important for the conventional landfill. In this study, aerobic pretreatment of mixed MSW was used, and much attention has been given to the natural convection of air in the mixed and unshredded MSW for bioconversion of organic matter (OM). This study is an attempt to investigate aerobic pretreatment suitability for the mixed and unshredded MSW at Beijing. A pilot-scale aerobic pretreatment simulator (APS) was developed at Beishen Shu Landfill in Beijing. To work out the biodegradation of the OM in the APS, fresh and pretreated MSW samples were collected and analyzed for OM, moisture content, temperature, chemical oxygen demand, total organic carbon, carbon, nitrogen, hydrogen, lignocelluloses, and biochemical methane potential at various stages of the pretreatment. Furthermore, results of the fresh and pretreated MSW are compared. Significant reduction in the observed parameters of the pretreated waste samples is observed. This work demonstrates that pretreatment is significantly effective in reducing the landfill emissions that is leachate and LFG.

Fungal pretreatment of willow sawdust and its combination with alkaline treatment for enhancing biogas production.

PubMed

Alexandropoulou, Maria; Antonopoulou, Georgia; Fragkou, Efsevia; Ntaikou, Ioanna; Lyberatos, Gerasimos

2017-12-01

In this study fungal pretreatment of willow sawdust (WSD) via the white rot fungi Leiotrametes menziesii and Abortiporus biennis was studied and the effect on fractionation of lignocellulosic biomass and biochemical methane potential (BMP), was evaluated. Scanning electron microscopy (SEM) and IR spectroscopy were used to investigate the changes in the structural characteristics of the pretreated WSD. Fungal pretreatment results revealed that A. biennis is more attractive, since it resulted in higher lignin degradation and lower holocellulose uptake. Samples of the 14th and 30th d of cultivation (i.e. the middle and the end of the pretreatment experiment) with both fungi were used for BMP tests and the effect of pretreatment duration was also evaluated. BMP increase by 31 and 43% was obtained due to the cultivation of WSD with A. biennis, for 14 and 30 d, respectively. In addition, combination of biological (after 30 d of cultivation) with alkaline (NaOH 20 g/100 gTS) pretreatment was performed, in order to assess the effect of the chemical agent on biologically pretreated WSD, in terms of lignocellulosic content and BMP. Combination of alkaline with fungal pretreatment led to high lignin degradation for both fungi, while the cellulose and hemicellulose removal efficiencies were higher for combined alkaline and L. menziesii pretreatment. The maximum BMP was observed for the combined alkaline and A. biennis pretreatment and was 12.5 and 50.1% higher than the respective alkaline and fungal pretreatment alone and 115% higher than the respective BMP of raw WSD. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effect of acid hydrolysis pretreatment on crystallinity and solubility of kenaf cellulose membrane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saidi, Anis Syuhada Mohd; Zakaria, Sarani; Chia, Chin Hua

2015-09-25

Cellulose was extracted from kenaf core pulp (KCP) by series of bleaching steps in the sequence (DEED) where D and E are referred as acid and alkali treatment. The bleached kenaf pulp (BKCP) is then pretreated with acid hydrolysis at room temperature for 1 and 3 h respectively. The pretreated cellulose is dissolved in lithium hydroxide/urea (LiOH/urea) and cellulose solution produced was immersed in distilled water bath. BKCP without treatment was also conducted for comparison purpose. The effects of acid hydrolysis pretreatment on solubility and crystallinity are investigated. Higher solubility of cellulose solution is achieved for treated samples. Cellulose II formationmore » and crystallinity index of the cellulose membrane were determined by X-ray diffraction (XRD)« less

Effects of alprazolam on capture stress-related serum cortisol responses in Korean raccoon dogs (Nyctereutes procyonoides koreensis)

PubMed Central

Kim, Sun-A; Lee, So-Yeong; Kimura, Junpei

2011-01-01

The purpose of this study was to evaluate the effect of alprazolam on the stress that Korean raccoon dogs (Nyctereutes procyonoides koreensis) may experience while caught in a live trap by measuring their serum cortisol response. The animals were placed in a live trap with or without being pretreated with oral doses of alprazolam. In both groups, pre-trap blood samples were initially collected without anesthesia before the animals were positioned in the live trap; then post-trap blood samples were collected after the animals had remained in the live trap for 2 h. Changes in cortisol levels were observed using a chemiluminescent immunoassay. The level of cortisol increased in the control group and decreased in the alprazolam-pretreatment group (p < 0.05). In this study, we demonstrated that alprazolam pretreatment reduced stress during live trap capture. PMID:21368571

Effects of alprazolam on capture stress-related serum cortisol responses in Korean raccoon dogs (Nyctereutes procyonoides koreensis).

PubMed

Kim, Sun-A; Lee, So-Yeong; Kimura, Junpei; Shin, Nam-Shik

2011-03-01

The purpose of this study was to evaluate the effect of alprazolam on the stress that Korean raccoon dogs (Nyctereutes procyonoides koreensis) may experience while caught in a live trap by measuring their serum cortisol response. The animals were placed in a live trap with or without being pretreated with oral doses of alprazolam. In both groups, pre-trap blood samples were initially collected without anesthesia before the animals were positioned in the live trap; then post-trap blood samples were collected after the animals had remained in the live trap for 2 h. Changes in cortisol levels were observed using a chemiluminescent immunoassay. The level of cortisol increased in the control group and decreased in the alprazolam-pretreatment group (p < 0.05). In this study, we demonstrated that alprazolam pretreatment reduced stress during live trap capture.

Influence of twin-screw extrusion on soluble arabinoxylans and corn fiber gum from corn fiber.

PubMed

Singkhornart, Sasathorn; Lee, Seul Gi; Ryu, Gi Hyung

2013-09-01

The effect of feed moisture content and screw speed in the extrusion process with and without chemical pretreatment of corn fiber was investigated. Different chemical pretreatment methods (NaOH and H2 SO4 solution) were compared. The improvement of reducing sugar, soluble arabinoxylans (SAX) content and the yield of corn fiber gum was measured. A high reducing sugar content was obtained in the filtrate fraction from the extruded destarched corn fiber (EDCF) with H₂SO₄ pretreatment. Feed moisture content most effectively improved both reducing sugar and SAX content of filtrate. Increasing feed moisture content and screw speed resulted in a higher SAX content in the filtrate of the EDCF with NaOH pretreatment. The SAX content of the residual solid from the EDCF with NaOH pretreatment was higher compared to H₂SO₄ pretreated and unpretreated samples and significantly increased with decreasing feed moisture content. The screw speed did not have a major impact after enzyme hydrolysis. The yield of corn fiber gum was increased by 12% using NaOH pretreatment combined with extrusion process as compared to the destarched corn fiber. The results show the great potential of the extrusion process as an effective pretreatment for disruption the lignocelluloses of corn fiber, leading to conversion of cellulose to glucose and hemicelluloses to SAX and isolation of corn fiber gum. © 2013 Society of Chemical Industry.

Effect of pretreatments on biogas production from microalgae biomass grown in pig manure treatment plants.

PubMed

Martín Juárez, Judit; Riol Pastor, Elena; Fernández Sevilla, José M; Muñoz Torre, Raúl; García-Encina, Pedro A; Bolado Rodríguez, Silvia

2018-06-01

Methane production from pretreated and raw mixed microalgae biomass grown in pig manure was evaluated. Acid and basic pretreatments provided the highest volatile solids solubilisation (up to 81%) followed by alkaline-peroxide and ultrasounds (23%). Bead milling and steam explosion remarkably increased the methane production rate, although the highest yield (377 mL CH 4 /g SV) was achieved by alkali pretreatment. Nevertheless, some pretreatments inhibited biogas production and resulted in lag phases of 7-9 days. Hence, experiments using only the pretreated solid phase were performed, which resulted in a decrease in the lag phase to 2-3 days for the alkali pretreatment and slightly increased biomass biodegradability of few samples. The limiting step during the BMP test (hydrolysis or microbial inhibition) for each pretreatment was elucidated using the goodness of fitting to a first order or a Gompertz model. Finally, the use of digestate as biofertilizer was evaluated applying a biorefinery concept. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ultrasound assisted biogas production from co-digestion of wastewater sludges and agricultural wastes: Comparison with microwave pre-treatment.

PubMed

Aylin Alagöz, B; Yenigün, Orhan; Erdinçler, Ayşen

2018-01-01

This study investigates the effect of ultrasonication and microwave sludge disintegration/pre-treatment techniques on the anaerobic co-digestion efficiency of wastewater sludges with olive and grape pomaces. The effects of both co-digestion and sludge pre-treatment techniques were evaluated in terms of the organic removal efficiency and the biogas production. The "co-digestion" of wastewater sludge with both types of pomaces was revealed to be a much more efficient way for the biogas production compared to the single (mono) sludge digestion. The ultrasonication and microwave pre-treatments applied to the sludge samples caused to a further increase in biogas and methane yields. Based on applied specific energies, ultrasonication pre-treatment was found much more effective than microwave irradiation. The specific energy applied in microwave pre-treatment (87,000kj/kgTS) was almost 9 times higher than that of used in ultrasonication (10,000kj/kgTS), resulting only 10-15% increases in biogas/methane yield. Co-digestion of winery and olive industry residues with pre-treated wastewater sludges appears to be a suitable technique for waste management and energy production. Copyright © 2017 Elsevier B.V. All rights reserved.

Hydrothermal pretreatment of microalgae for production of pyrolytic bio-oil with a low nitrogen content.

PubMed

Du, Zhenyi; Mohr, Michael; Ma, Xiaochen; Cheng, Yanling; Lin, Xiangyang; Liu, Yuhuan; Zhou, Wenguang; Chen, Paul; Ruan, Roger

2012-09-01

Microalgae can be converted to an energy-dense bio-oil via pyrolysis; however, the relatively high nitrogen content of this bio-oil presents a challenge for its direct use as fuels. Therefore, hydrothermal pretreatment was employed to reduce the N content in Nannochloropsis oculata feedstock by removing proteins without requiring significant energy inputs. The effects of reaction conditions on the yield and composition of pretreated algae were investigated by varying the temperature (150-225°C) and reaction time (10-60 min). Compared with untreated algae, pretreated samples had higher carbon contents and enhanced heating values under all reaction conditions and 6-42% lower N contents at 200-225°C for 30-60 min. The pyrolytic bio-oil from pretreated algae contained less N-containing compounds than that from untreated samples and the bio-oil contained mainly (44.9% GC-MS peak area) long-chain fatty acids (C14-C18) which can be more readily converted into hydrocarbon fuels in the presence of simple catalysts. Copyright © 2012 Elsevier Ltd. All rights reserved.

Combined pretreatment with hot compressed water and wet disk milling opened up oil palm biomass structure resulting in enhanced enzymatic digestibility.

PubMed

Zakaria, Mohd Rafein; Hirata, Satoshi; Fujimoto, Shinji; Hassan, Mohd Ali

2015-10-01

Combined pretreatment with hot compressed water and wet disk milling was performed with the aim to reduce the natural recalcitrance of oil palm biomass by opening its structure and provide maximal access to cellulase attack. Oil palm empty fruit bunch and oil palm frond fiber were first hydrothermally pretreated at 150-190° C and 10-240 min. Further treatment with wet disk milling resulted in nanofibrillation of fiber which caused the loosening of the tight biomass structure, thus increasing the subsequent enzymatic conversion of cellulose to glucose. The effectiveness of the combined pretreatments was evaluated by chemical composition changes, power consumption, morphological alterations by SEM and the enzymatic digestibility of treated samples. At optimal pretreatment process, approximately 88.5% and 100.0% of total sugar yields were obtained from oil palm empty fruit bunch and oil palm frond fiber samples, which only consumed about 15.1 and 23.5 MJ/kg of biomass, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pretreatment of Oil Palm Frond (OPF) with Ionic Liquid

NASA Astrophysics Data System (ADS)

Azmi, I. S.; Azizan, A.; Salleh, R. Mohd

2018-05-01

Pretreatment is the key to unlock the recalcitrance of lignocellulose for cellulosic biofuel production. Increasing attention has been drawn to ionic liquids (ILs) for pretreatment of lignocellulosic biomass because this approach was considered as a green engineering method over other conventional methods. In this work, Oil palm frond (OPF) was pretreated by using the ionic liquid 1-ethyl-3-methylimidazolium acetate [EMIM] Ac at the temperature of 99˚C for 3 hours. The characterization of the untreated and pretreated OPF was conducted by using different techniques which are Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The pretreatment of OPF with [EMIM] Ac was demonstrated to be effective evidenced by the significant reduction of Lateral Order Index (LOI) from FTIR, reduction of Crystallinity Index (CI) based on XRD and the significant morphology changes indicated by SEM. The CI value for the pretreated OPF decreased from 0.47 (untreated sample) to 0.28 while the LOI value decreased from 1.10 to 0.24 after pretreatment with [EMIM]Ac and the SEM morphology showed that the pretreated OPF becomes distorted and disordered.

Microwave-assisted co-pyrolysis of pretreated lignin and soapstock for upgrading liquid oil: Effect of pretreatment parameters on pyrolysis behavior.

PubMed

Duan, Dengle; Ruan, Roger; Lei, Hanwu; Liu, Yuhuan; Wang, Yunpu; Zhang, Yayun; Zhao, Yunfeng; Dai, Leilei; Wu, Qiuhao; Zhang, Shumei

2018-06-01

The co-pyrolysis of pretreated lignin and soapstock was carried out to upgrade vapors under microwave irradiation. Results showed that the yield of 29.92-42.21 wt% of upgraded liquid oil was achieved under varied pretreatment conditions. Char yield decreased from 32.44 wt% for untreated control to 24.35 wt% for the 150 °C pretreated samples. The increased temperature, irradiation time and acid concentration were conducive to decrease the relative contents of phenols and oxygenates in liquid oils. The main components of the liquid oil were gasoline fraction (mono-aromatics and C5-C12 aliphatics), which ranged from 57.38 to 71.98% under various pretreatment conditions. Meanwhile, the diesel fraction (C12+ aliphatics) ranged from 13.16 to 22.62% from co-pyrolysis of pretreated lignin and soapstock, comparing with 10.18% of C12+ aliphatics from co-pyrolysis of non-pretreated lignin and soapstock. A possible mechanism was proposed for co-pyrolysis of pretreated lignin and soapstock for upgraded liquid oils. Copyright © 2018 Elsevier Ltd. All rights reserved.

Inhibitive effects of anti-oxidative vitamins on mannitol-induced apoptosis of vascular endothelial cells.

PubMed

Pan, Kai-yu; Shen, Mei-ping; Ye, Zhi-hong; Dai, Xiao-na; Shang, Shi-qiang

2006-10-01

Study blood vessel injury and gene expression indicating vascular endothelial cell apoptosis induced by mannitol with and without administration of anti-oxidative vitamins. Healthy rabbits were randomly divided into four groups. Mannitol was injected into the vein of the rabbit ear in each animal. Pre-treatment prior to mannitol injection was performed with normal saline (group B), vitamin C (group C) and vitamin E (group D). Blood vessel injury was assessed under electron and light microscopy. In a second experiment, cell culture specimen of human umbilical vein endothelial cells were treated with mannitol. Pre-treatment was done with normal saline (sample B), vitamin C (sample C) and vitamin E (sample D). Total RNA was extracted with the original single step procedure, followed by hybridisation and analysis of gene expression. In the animal experiment, serious blood vessel injury was seen in group A and group B. Group D showed light injury only, and normal tissue without pathological changes was seen in group C. Of all 330 apoptosis-related genes analysed in human cell culture specimen, no significant difference was seen after pre-treatment with normal saline, compared with the gene chip without pre-treatment. On the gene chip pre-treated with vitamin C, 45 apoptosis genes were down-regulated and 34 anti-apoptosis genes were up-regulated. Pre-treatment with vitamin E resulted in the down-regulation of 3 apoptosis genes. Vitamin C can protect vascular endothelial cells from mannitol-induced injury.

The effects of chemical and physical penetration enhancers on the percutaneous permeation of lidocaine through equine skin

PubMed Central

2014-01-01

Background The effect of physical and chemical permeation enhancers on in vitro transdermal permeation of lidocaine was investigated in the horse. Therefore, the effect of six vehicles (phosphate-buffered saline (PBS), 50% ethanol, 50% propylene glycol, 50% isopropylalcohol, 50% isopropylalcohol/isopropylmyristate and 50% dimethylsulfoxide) was examined as well as the effect of microneedle pretreatment with different needle lengths on transdermal drug delivery of lidocaine. The skin was obtained from the thorax of six Warmblood horses and was stored up to two weeks at - 20°C. Franz-type diffusion cells were used to study the transdermal permeation through split skin (600 μm thickness). The amount of lidocaine in the receptor fluid was determined by UV–VIS high-performance liquid chromatography. Results All investigated vehicle supplementations diminished the transdermal flux of lidocaine through equine skin in comparison to pure PBS except dimethylsulfoxide, which resulted in comparable permeation rates to PBS. The maximum flux (Jmax) was 1.6-1.8 fold lower for lidocaine applied in 50% ethanol, propylene glycol, isopropylalcohol and isopropylalcohol/isopropylmyristate. A significant higher Jmax of lidocaine was observed when lidocaine was applied in PBS onto microneedle pretreated skin with similar permeation rates in both needle lengths. After 6 hours, 1.7 fold higher recovery rates were observed in the microneedle pretreated skin samples than in the untreated control samples. The lagtimes were reduced to 20–50% in the microneedle pretreated skin samples. Conclusion Microneedles represent a promising tool for transdermal lidocaine application in the horse with a rapid systemic bioavailability. PMID:24950611

Effects of Dilute Acid Pretreatment on Cellulose DP and the Relationship Between DP Reduction and Cellulose Digestibility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, W.; Chen, X.; Tucker, M.

2012-01-01

The degree of polymerization(DP) of cellulose is considered to be one of the most important properties affecting the enzymatic hydrolysis of cellulose. Various pure cellulosic and biomass materials have been used in a study of the effect of dilute acid treatment on cellulose DP. A substantial reduction in DP was found for all pure cellulosic materials studied even at conditions that would be considered relatively mild for pretreatment. The effect of dilute acid pretreatment on cellulose DP in biomass samples was also investigated. Corn stover pretreated with dilute acid under the most optimal conditions contained cellulose with a DPw inmore » the range of 1600{approx}3500, which is much higher than the level-off DP(DPw 150{approx}300) obtained with pure celluloses. The effect of DP reduction on the saccharification of celluloses was also studied. From this study it does not appear that cellulose DP is a main factor affecting cellulose saccharification.« less

Fast pyrolysis of tropical biomass species and influence of water pretreatment on product distributions

DOE PAGES

Morgan, Trevor James; Turn, Scott Q.; Sun, Ning; ...

2016-03-15

Here, the fast pyrolysis behaviour of pretreated banagrass was examined at four temperatures (between 400 and 600 C) and four residence times (between ~1.2 and 12 s). The pretreatment used water washing/leaching to reduce the inorganic content of the banagrass. Yields of bio-oil, permanent gases and char were determined at each reaction condition and compared to previously published results from untreated banagrass. Comparing the bio-oil yields from the untreated and pretreated banagrass shows that the yields were greater from the pretreated banagrass by 4 to 11 wt% (absolute) at all reaction conditions. The effect of pretreatment (i.e. reducing the amountmore » of ash, and alkali and alkali earth metals) on pyrolysis products is: 1) to increase the dry bio-oil yield, 2) to decrease the amount of undetected material, 3) to produce a slight increase in CO yield or no change, 4) to slightly decrease CO 2 yield or no change, and 5) to produce a more stable bio-oil (less aging). Char yield and total gas yield were unaffected by feedstock pretreatment. Four other tropical biomass species were also pyrolyzed under one condition (450°C and 1.4 s residence time) for comparison to the banagrass results. The samples include two hardwoods: leucaena and eucalyptus, and two grasses: sugarcane bagasse and energy-cane. A sample of pretreated energy-cane was also pyrolyzed. Of the materials tested, the best feedstocks for fast pyrolysis were sugarcane bagasse, pretreated energy cane and eucalyptus based on the yields of 'dry bio-oil', CO and CO 2. On the same basis, the least productive feedstocks are untreated banagrass followed by pretreated banagrass and leucaena.« less

Fast pyrolysis of tropical biomass species and influence of water pretreatment on product distributions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morgan, Trevor James; Turn, Scott Q.; Sun, Ning

Here, the fast pyrolysis behaviour of pretreated banagrass was examined at four temperatures (between 400 and 600 C) and four residence times (between ~1.2 and 12 s). The pretreatment used water washing/leaching to reduce the inorganic content of the banagrass. Yields of bio-oil, permanent gases and char were determined at each reaction condition and compared to previously published results from untreated banagrass. Comparing the bio-oil yields from the untreated and pretreated banagrass shows that the yields were greater from the pretreated banagrass by 4 to 11 wt% (absolute) at all reaction conditions. The effect of pretreatment (i.e. reducing the amountmore » of ash, and alkali and alkali earth metals) on pyrolysis products is: 1) to increase the dry bio-oil yield, 2) to decrease the amount of undetected material, 3) to produce a slight increase in CO yield or no change, 4) to slightly decrease CO 2 yield or no change, and 5) to produce a more stable bio-oil (less aging). Char yield and total gas yield were unaffected by feedstock pretreatment. Four other tropical biomass species were also pyrolyzed under one condition (450°C and 1.4 s residence time) for comparison to the banagrass results. The samples include two hardwoods: leucaena and eucalyptus, and two grasses: sugarcane bagasse and energy-cane. A sample of pretreated energy-cane was also pyrolyzed. Of the materials tested, the best feedstocks for fast pyrolysis were sugarcane bagasse, pretreated energy cane and eucalyptus based on the yields of 'dry bio-oil', CO and CO 2. On the same basis, the least productive feedstocks are untreated banagrass followed by pretreated banagrass and leucaena.« less

Fast Pyrolysis of Tropical Biomass Species and Influence of Water Pretreatment on Product Distributions

PubMed Central

Morgan, Trevor James; Turn, Scott Q.; Sun, Ning; George, Anthe

2016-01-01

The fast pyrolysis behaviour of pretreated banagrass was examined at four temperatures (between 400 and 600 C) and four residence times (between ~1.2 and 12 s). The pretreatment used water washing/leaching to reduce the inorganic content of the banagrass. Yields of bio-oil, permanent gases and char were determined at each reaction condition and compared to previously published results from untreated banagrass. Comparing the bio-oil yields from the untreated and pretreated banagrass shows that the yields were greater from the pretreated banagrass by 4 to 11 wt% (absolute) at all reaction conditions. The effect of pretreatment (i.e. reducing the amount of ash, and alkali and alkali earth metals) on pyrolysis products is: 1) to increase the dry bio-oil yield, 2) to decrease the amount of undetected material, 3) to produce a slight increase in CO yield or no change, 4) to slightly decrease CO2 yield or no change, and 5) to produce a more stable bio-oil (less aging). Char yield and total gas yield were unaffected by feedstock pretreatment. Four other tropical biomass species were also pyrolyzed under one condition (450°C and 1.4 s residence time) for comparison to the banagrass results. The samples include two hardwoods: leucaena and eucalyptus, and two grasses: sugarcane bagasse and energy-cane. A sample of pretreated energy-cane was also pyrolyzed. Of the materials tested, the best feedstocks for fast pyrolysis were sugarcane bagasse, pretreated energy cane and eucalyptus based on the yields of 'dry bio-oil', CO and CO2. On the same basis, the least productive feedstocks are untreated banagrass followed by pretreated banagrass and leucaena. PMID:26978265

Fast Pyrolysis of Tropical Biomass Species and Influence of Water Pretreatment on Product Distributions.

PubMed

Morgan, Trevor James; Turn, Scott Q; Sun, Ning; George, Anthe

2016-01-01

The fast pyrolysis behaviour of pretreated banagrass was examined at four temperatures (between 400 and 600 C) and four residence times (between ~1.2 and 12 s). The pretreatment used water washing/leaching to reduce the inorganic content of the banagrass. Yields of bio-oil, permanent gases and char were determined at each reaction condition and compared to previously published results from untreated banagrass. Comparing the bio-oil yields from the untreated and pretreated banagrass shows that the yields were greater from the pretreated banagrass by 4 to 11 wt% (absolute) at all reaction conditions. The effect of pretreatment (i.e. reducing the amount of ash, and alkali and alkali earth metals) on pyrolysis products is: 1) to increase the dry bio-oil yield, 2) to decrease the amount of undetected material, 3) to produce a slight increase in CO yield or no change, 4) to slightly decrease CO2 yield or no change, and 5) to produce a more stable bio-oil (less aging). Char yield and total gas yield were unaffected by feedstock pretreatment. Four other tropical biomass species were also pyrolyzed under one condition (450°C and 1.4 s residence time) for comparison to the banagrass results. The samples include two hardwoods: leucaena and eucalyptus, and two grasses: sugarcane bagasse and energy-cane. A sample of pretreated energy-cane was also pyrolyzed. Of the materials tested, the best feedstocks for fast pyrolysis were sugarcane bagasse, pretreated energy cane and eucalyptus based on the yields of 'dry bio-oil', CO and CO2. On the same basis, the least productive feedstocks are untreated banagrass followed by pretreated banagrass and leucaena.

Supercritical fluids as a green technology for the pretreatment of lignocellulosic biomass.

PubMed

Daza Serna, L V; Orrego Alzate, C E; Cardona Alzate, C A

2016-01-01

One of the main drawbacks for using lignocellulosic biomass is related to its recalcitrance. The pretreatment of lignocellulosic biomass plays an important role for delignification and crystallinity reduction purposes. In this work rice husk (RH) was submitted to supercritical pretreatment at 80°C and 270 bar with the aim to determine the effect on lignin content, crystallinity as well as enzymatic digestibility. The yields obtained were compared with dilute sulfuric acid pretreatment as base case. Additionally a techno-economic and environmental comparison of the both pretreatment technologies was performed. The results show a lignin content reduction up to 90.6% for the sample with 75% moisture content using a water-ethanol mixture. The results for crystallinity and enzymatic digestibility demonstrated that no reductions were reached. Supercritical pretreatment presents the best economical and environmental performance considering the solvents and carbon dioxide recycling. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of ultrasound treatment on the water state in kiwifruit during osmotic dehydration.

PubMed

Nowacka, M; Tylewicz, U; Laghi, L; Dalla Rosa, M; Witrowa-Rajchert, D

2014-02-01

The present work investigates how ultrasound pretreatment modulates the effects of osmotic dehydration (OD) on the water state and microstructure of kiwifruit. Kiwifruit slices (10mm thick) were subjected to ultrasonic waves in a water bath at a frequency of 35 kHz for 10, 20 and 30 min. OD process was then carried out by immersing the samples in 61.5% sucrose solution equilibrated at 25°C for a contact period of 0, 10, 20, 30, 60 and 120 min. The partition of water into the cellular tissue structures (vacuole, cytoplasm, extracellular spaces and cell wall) was investigated by Time Domain Nuclear Magnetic Resonance (TD-NMR). In parallel, the microstructure of kiwifruits slices was examined using a Scanning Electron Microscope. The results showed that US pretreatment performed for more than 10 min had a positive effect on the mass exchange caused by osmotic dehydration. A creation of microchannels and an increase of the average cross-section area of cells were observed when the samples were pretreated with US before OD. TD-NMR showed a slight redistribution of water through the substructures of the cells, as a function of the length of the US pretreatment applied. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

A citrus waste-based biorefinery as a source of renewable energy: technical advances and analysis of engineering challenges.

PubMed

Rivas-Cantu, Raul C; Jones, Kim D; Mills, Patrick L

2013-04-01

An assessment of recent technical advances on pretreatment processes and its effects on enzymatic hydrolysis as the main steps of a proposed citrus processing waste (CPW) biorefinery is presented. Engineering challenges and relevant gaps in scientific and technical information for reliable design, modeling and scale up of a CPW biorefinery are also discussed. Some integrated physico-chemical pretreatments are proposed for testing for CPW, including high speed knife-grinding and simultaneous caustic addition. These new proposed processes and the effect of parameters such as particle size, surface area and morphology, pore volume and chemical composition of the diverse fractions resulting from pretreatment and enzymatic hydrolysis need to be evaluated and compared for pretreated and untreated samples of grapefruit processing waste. This assessment suggests the potential for filling the data gaps, and preliminary results demonstrate that the reduction of particle size and the increased surface area for the CPW will result in higher reaction rates and monosaccharide yields for the pretreated waste material.

Biological abatement of cellulase inhibitors.

PubMed

Cao, Guangli; Ximenes, Eduardo; Nichols, Nancy N; Zhang, Leyu; Ladisch, Michael

2013-10-01

Removal of enzyme inhibitors released during lignocellulose pretreatment is essential for economically feasible biofuel production. We tested bio-abatement to mitigate enzyme inhibitor effects observed in corn stover liquors after pretreatment with either dilute acid or liquid hot water at 10% (w/v) solids. Bio-abatement of liquors was followed by enzymatic hydrolysis of cellulose. To distinguish between inhibitor effects on enzymes and recalcitrance of the substrate, pretreated corn stover solids were removed and replaced with 1% (w/v) Solka Floc. Cellulose conversion in the presence of bio-abated liquors from dilute acid pretreatment was 8.6% (0.1x enzyme) and 16% (1x enzyme) higher than control (non-abated) samples. In the presence of bio-abated liquor from liquid hot water pretreated corn stover, 10% (0.1x enzyme) and 13% (1x enzyme) higher cellulose conversion was obtained compared to control. Bio-abatement yielded improved enzyme hydrolysis in the same range as that obtained using a chemical (overliming) method for mitigating inhibitors. Copyright © 2013 Elsevier Ltd. All rights reserved.

Glycerol carbonate as green solvent for pretreatment of sugarcane bagasse

PubMed Central

2013-01-01

Background Pretreatment of lignocellulosic biomass is a prerequisite for effective saccharification to produce fermentable sugars. In this study, “green” solvent systems based on acidified mixtures of glycerol carbonate (GC) and glycerol were used to treat sugarcane bagasse and the roles of each solvent in deconstructing biomass were determined. Results Pretreatment of sugarcane bagasse at 90°C for only 30 min with acidified GC produced a solid residue having a glucan digestibility of 90% and a glucose yield of 80%, which were significantly higher than a glucan digestibility of 16% and a glucose yield of 15% obtained for bagasse pretreated with acidified ethylene carbonate (EC). Biomass compositional analyses showed that GC pretreatment removed more lignin than EC pretreatment (84% vs 54%). Scanning electron microscopy (SEM) showed that fluffy and size-reduced fibres were produced from GC pretreatment whereas EC pretreatment produced compact particles of reduced size. The maximal glucan digestibility and glucose yield of GC/glycerol systems were about 7% lower than those of EC/ethylene glycol (EG) systems. Replacing up to 50 wt% of GC with glycerol did not negatively affect glucan digestibility and glucose yield. The results from pretreatment of microcrystalline cellulose (MCC) showed that (1) pretreatment with acidified alkylene glycol (AG) alone increased enzymatic digestibility compared to pretreatments with acidified alkylene carbonate (AC) alone and acidified mixtures of AC and AG, (2) pretreatment with acidified GC alone slightly increased, but with acidified EC alone significantly decreased, enzymatic digestibility compared to untreated MCC, and (3) there was a good positive linear correlation of enzymatic digestibility of treated and untreated MCC samples with congo red (CR) adsorption capacity. Conclusions Acidified GC alone was a more effective solvent for pretreatment of sugarcane bagasse than acidified EC alone. The higher glucose yield obtained with GC-pretreated bagasse is possibly due to the presence of one hydroxyl group in the GC molecular structure, resulting in more significant biomass delignification and defibrillation, though both solvent pretreatments reduced bagasse particles to a similar extent. The maximum glucan digestibility of GC/glycerol systems was less than that of EC/EG systems, which is likely attributed to glycerol being less effective than EG in biomass delignification and defibrillation. Acidified AC/AG solvent systems were more effective for pretreatment of lignin-containing biomass than MCC. PMID:24156757

Alkaline-sulfite pretreatment and use of surfactants during enzymatic hydrolysis to enhance ethanol production from sugarcane bagasse.

PubMed

Mesquita, Jéssica Faria; Ferraz, André; Aguiar, André

2016-03-01

Sugarcane bagasse is a by-product from the sugar and ethanol industry which contains approximately 70 % of its dry mass composed by polysaccharides. To convert these polysaccharides into fuel ethanol it is necessary a pretreatment step to increase the enzymatic digestibility of the recalcitrant raw material. In this work, sugarcane bagasse was pretreated by an alkaline-sulfite chemithermomechanical process for increasing its enzymatic digestibility. Na2SO3 and NaOH ratios were fixed at 2:1, and three increasing chemical loads, varying from 4 to 8 % m/m Na2SO3, were used to prepare the pretreated materials. The increase in the alkaline-sulfite load decreased the lignin content in the pretreated material up to 35.5 % at the highest chemical load. The pretreated samples presented enhanced glucose yields during enzymatic hydrolysis as a function of the pretreatment severity. The maximum glucose yield (64 %) was observed for the samples pretreated with the highest chemical load. The use of 2.5 g l(-1) Tween 20 in the hydrolysis step further increased the glucose yield to 75 %. Semi-simultaneous hydrolysis and fermentation of the pretreated materials indicated that the ethanol yield was also enhanced as a function of the pretreatment severity. The maximum ethanol yield was 56 ± 2 % for the sample pretreated with the highest chemical load. For the sample pretreated with the lowest chemical load (2 % m/m NaOH and 4 % m/m Na2SO3), adding Tween 20 during the hydrolysis process increased the ethanol yield from 25 ± 3 to 39.5 ± 1 %.

Associating cooking additives with sodium hydroxide to pretreat bamboo residues for improving the enzymatic saccharification and monosaccharides production.

PubMed

Huang, Caoxing; He, Juan; Wang, Yan; Min, Douyong; Yong, Qiang

2015-10-01

Cooking additive pulping technique is used in kraft mill to increase delignification degree and pulp yield. In this work, cooking additives were firstly applied in the sodium hydroxide pretreatment for improving the bioconversion of bamboo residues to monosaccharides. Meanwhile, steam explosion and sulfuric acid pretreatments were also carried out on the sample to compare their impacts on monosaccharides production. Results indicated that associating anthraquinone with sodium hydroxide pretreatment showed the best performance in improving the original carbohydrates recovery, delignification, enzymatic saccharification, and monosaccharides production. After consecutive pretreatment and enzymatic saccharification process, 347.49 g, 307.48 g, 142.93 g, and 87.15 g of monosaccharides were released from 1000 g dry bamboo residues pretreated by sodium hydroxide associating with anthraquinone, sodium hydroxide, steam explosion and sulfuric acid, respectively. The results suggested that associating cooking additive with sodium hydroxide is an effective pretreatment for bamboo residues to enhance enzymatic saccharification for monosaccharides production. Copyright © 2015 Elsevier Ltd. All rights reserved.

Rapid LC-MS/MS quantification of the major benzodiazepines and their metabolites on dried blood spots using a simple and cost-effective sample pretreatment.

PubMed

Déglon, Julien; Versace, François; Lauer, Estelle; Widmer, Christèle; Mangin, Patrice; Thomas, Aurélien; Staub, Christian

2012-06-01

Dried blood spots (DBS) sampling has gained popularity in the bioanalytical community as an alternative to conventional plasma sampling, as it provides numerous benefits in terms of sample collection and logistics. The aim of this work was to show that these advantages can be coupled with a simple and cost-effective sample pretreatment, with subsequent rapid LC-MS/MS analysis for quantitation of 15 benzodiazepines, six metabolites and three Z-drugs. For this purpose, a simplified offline procedure was developed that consisted of letting a 5-µl DBS infuse directly into 100 µl of MeOH, in a conventional LC vial. The parameters related to the DBS pretreatment, such as extraction time or internal standard addition, were investigated and optimized, demonstrating that passive infusion in a regular LC vial was sufficient to quantitatively extract the analytes of interest. The method was validated according to international criteria in the therapeutic concentration ranges of the selected compounds. The presented strategy proved to be efficient for the rapid analysis of the selected drugs. Indeed, the offline sample preparation was reduced to a minimum, using a small amount of organic solvent and consumables, without affecting the accuracy of the method. Thus, this approach enables simple and rapid DBS analysis, even when using a non-DBS-dedicated autosampler, while lowering the costs and environmental impact.

Determination of germanium by AAS in chloride-containing matrices.

PubMed

Anwari, M A; Abbasi, H U; Volkan, M; Ataman, O Y

1996-06-01

Interference effects of NaCl on the ET-AAS determination of Ge have been studied. The use of several matrix modifiers to alleviate this problem such as Ni and Zn perchlorates and nitrates, nitric acid, ammonium nitrate are reported. The stabilizing effect of Zn and Ni perchlorates allows the use of high pretreatment temperatures. NaCl is thus thermally volatilized from the atomizer by employing pretreatment temperatures higher than 1500 degrees C resulting in an improved sensitivity. Germanium levels in zinc plant slag samples, have been determined and compared to those obtained for the same samples spiked with NaCl with platform and wall atomization using nickel perchlorate as a matrix modifier. The results were compared with those from a hydride generation system equipped with a liquid nitrogen trap. The recoveries for germanium have been almost complete and amount to 99% for the original slag samples and 80% for 15% (w/w) NaCl containing spiked samples.

Human Mesenchymal Stem Cells Pretreated with Interleukin-1β and Stimulated with Bone Morphogenetic Growth Factor-3 Enhance Chondrogenesis.

PubMed

Hingert, Daphne; Barreto Henriksson, Helena; Brisby, Helena

2018-05-01

Low back pain is one of the most common ailments in western countries afflicting more than 80% of the population, and the main cause is considered to be degeneration of intervertebral discs. Interleukin-1β (IL-1β) is a vital inflammatory cytokine found in abundance in degenerated disc environment, whereas bone morphogenetic growth factor-3 (BMP-3) is believed to promote chondrogenesis through transforming growth factor-beta (TGF-β) pathway. The aim was to study the effects of BMP-3, IL-1β, and combination (pretreatment with IL-1β) on human mesenchymal stem cells (hMSCs) encapsulated in PuraMatrix™ hydrogel (Phg) especially in the absence of TGF-β in order to investigate the proliferation and differentiation ability of hMSCs over 28-day period. One hundred microliters of hMSCs' cell suspension was encapsulated between two layers of 100 μL hydrogels forming a sandwich-like structure. The encapsulated hMSCs were cultured in two sets of media, chondrogenic (C) and nonchondrogenic (nC) media, along with addition of BMP-3 (10 ng/mL) and IL-1β (10 ng/mL). To study the combined effects of BMP-3 and IL-1β, the encapsulated hMSCs were first pretreated with relevant media containing IL-1β for 24 h, and then the media was replaced by media containing BMP-3 for the remaining experimental time period. IL-1β pretreatment was carried out in both C and nC media. The samples were collected at day 7, 14, and 28. Proliferation and differentiation of hMSCs into chondrocyte-like cells were observed in all samples. Proteoglycan accumulation was observed in pretreatment samples in C media. The protein and gene expression of Sox-9 and COL2A1, respectively, showed the occurrence of chondrogenesis in all samples. High cell viability, proliferation, and differentiation were achieved in this in vitro model confirming that BMP-3 alone in the absence of TGF-β could drive hMSCs into chondrogenic lineage. Pretreatment with IL-1β followed by BMP-3 stimulation resulted in high proteoglycan accumulation compared to stimulation with growth factors or cytokine alone. This suggests that pretreatment with a pro-inflammatory cytokine before driving them into a chondrogenic lineage might be of importance also in vivo.

Effect of different pretreatments on dried chilli (Capsicum annum L.) quality

NASA Astrophysics Data System (ADS)

Anoraga, S. B.; Sabarisman, I.; Ainuri, M.

2018-03-01

Chilli (Capsicum annum L.) has significant price fluctuation. When the chilli price is declined, it causes food waste from unsold chilli. Therefore, drying chilli is a solution for this condition. Futhermore, it can be processed for various product like chilli powder, chilli sauce, etc. The aim of this study was to investigate the effect of different pretreatments on dried chilli quality. Chilli was blenched with hot water and steam before drying. The purpose of this pretreatments is to inactivate enzyme that prevents color and vitamin C losses. The quality parameters were moisture content, colour, vitamin C content, and capsaicin. Changes were observed by gravimetri method for moisture content, chromameter in L* a * b * colour model, and iodine titration for vitamin C. After drying for 20 hours at 60°C, chilli with steam blanching pretreatment dried rapidly than other samples. Unpretreated chilli had higher vitamin C content and better color than blanched chilli.

Postharvest Ultrasound-Assisted Freeze-Thaw Pretreatment Improves the Drying Efficiency, Physicochemical Properties, and Macamide Biosynthesis of Maca (Lepidium meyenii).

PubMed

Chen, Jin-Jin; Gong, Peng-Fei; Liu, Yi-Lan; Liu, Bo-Yan; Eggert, Dawn; Guo, Yuan-Heng; Zhao, Ming-Xia; Zhao, Qing-Sheng; Zhao, Bing

2018-04-01

A novel technique of ultrasound-assisted freeze-thaw pretreatment (UFP) was developed to improve the drying efficiency of maca and bioactive amide synthesis in maca. The optimal UFP conditions are ultrasonic processing 90 min at 30 °C with 6 freeze-thaw cycles. Samples with freeze-thaw pretreatment (FP), ultrasound pretreatment (UP), and UFP were prepared for further comparative study. A no pretreatment (NP) sample was included as a control. The results showed that UFP improved the drying efficiency of maca slices, showing the highest effective moisture diffusivity (1.75 × 10 -9 m 2 /s). This result was further supported by low-field nuclear magnetic resonance (LF-NMR) analysis and scanning electron microscopy (SEM). The rehydration capacity and protein content of maca slices were improved by UFP. More importantly, contents of bioactive macamides and their biosynthetic precursors were increased in 2.5- and 10-fold, respectively. In conclusion, UFP is an efficient technique to improve drying efficiency, physicochemical properties, and bioactive macamides of maca, which can be applied in the industrial manufacture of maca products. © 2018 Institute of Food Technologists®.

Fracture surface analysis in composite and titanium bonding: Part 1: Titanium bonding

NASA Technical Reports Server (NTRS)

Sanderson, K. A.; Wightman, J. P.

1985-01-01

Fractured lap shear Ti 6-4 adherends bonded with polyphenyquinoxaline (PPQ) and polysulfone were analyzed. The effects of adherend pretreatment, stress level, thermal aging, anodizing voltage, and modified adhesive of Ti 6-4 adherend bonded with PPQ on lap shear strength were studied. The effect of adherend pretreatment on lap shear strength was investigated for PS samples. Results of scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) used to study the surface topography and surface composition are also discussed.

Ultrasound pretreatment for enhanced biogas production from olive mill wastewater.

PubMed

Oz, Nilgun Ayman; Uzun, Alev Cagla

2015-01-01

This study investigates applicability of low frequency ultrasound technology to olive mill wastewaters (OMWs) as a pretreatment step prior to anaerobic batch reactors to improve biogas production and methane yield. OMWs originating from three phase processes are characterized with high organic content and complex nature. The treatment of the wastewater is problematic and alternative treatment options should be investigated. In the first part of the study, OMW samples were subjected to ultrasound at a frequency of 20kHz with applied powers varying between 50 and 100W under temperature controlled conditions for different time periods in order to determine the most effective sonication conditions. The level of organic matter solubilization at ultrasound experiments was assessed by calculating the ratio of soluble chemical oxygen demand/total chemical oxygen demand (SCOD/TCOD). The results revealed that the optimum ultrasonic condition for diluted OMW is 20kHz, 0.4W/mL for 10min. The application of ultrasound to OMW increased SCOD/TCOD ratio from 0.59 to 0.79. Statistical analysis (Friedman's tests) show that ultrasound was significantly effective on diluted OMW (p<0.05) in terms of SCOD parameter, but not for raw OMW (p>0.05). For raw OMW, this increase has been found to be limited due to high concentration of suspended solids (SS). In the second part of the study, biogas and methane production rates of anaerobic batch reactor fed with the ultrasound pretreated OMW samples were compared with the results of control reactor fed with untreated OMW in order to determine the effect of sonication. A nonparametric statistical procedure, Mann-Whitney U test, was used to compare biogas and methane production from anaerobic batch reactors for control and ultrasound pretreated samples. Results showed that application of low frequency ultrasound to OMW significantly improved both biogas and methane production in anaerobic batch reactor fed with the wastewater (p<0.05). Anaerobic batch reactor fed with ultrasound pretreated diluted OMW produced approximately 20% more biogas and methane compared with the untreated one (control reactor). The overall results indicated that low frequency ultrasound pretreatment increased soluble COD in OMW and subsequently biogas production. Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of postharvest pretreatments on organic Early Superior Seedless "Sugraone" table grapes assigned to long term storage

NASA Astrophysics Data System (ADS)

Admane, Naouel; Verrastro, Vincenzo; Di Gennaro, Domenico; Genovese, Francesco; Altieri, Giuseppe; Carlo Di Renzo, Giovanni

2014-05-01

Every year a significant amount of organic table grapes is lost during postharvest mainly due to the incidence of decay, stem browning and fast alteration of the taste and aroma. The demand for this fresh product with immaculate appearance and high sensory quality in terms of flavor, is a hard challenge considering the difficulties to conserve them, with alternative safe treatments to the sulphur dioxide (SO2) which is not allowed in organic product. The aim of this experiment was to maintain the quality of organic table grapes and extend their shelf-life for medium and long term, in order to reach new distant promising markets, by using safe methods. The effectiveness of the combination of pretreatment with Generally Recognized As Safe (GRAS) compounds, physical means and storage under modified atmosphere packaging (MAP) were performed by using detached organic table grape berries as alternatives to usual industrial SO2 application. The detached organic Early Superior Seedless "Sugraone" berries were pretreated by: i) dipping in ethanol and potassium bicarbonate; ii) massive CO2 concentrations; iii) ozone (O3) fumigation; whereas, untreated berries were included in the trial as control. Moreover, all the samples were packed in thermo-sealed ALPAK bags with MAP of 2% O2:5% CO2:93% N2 and stored at 0°C for 45 days. Initially and after 15, 30 and 45 days of storage, weight loss, decay incidence, berry/skin firmness, pedicel detachment force, skin color parameters, SSC, pH, titratable acidity and sensory evaluation scores, were monitored. After 45 days of storage, the weight loss was higher in the sample pretreated with massive CO2 concentration at 70 - 90 % and the control. The samples pretreated with CO2 at 70% and O3 at 20 ppm maintained the strength of the berry linked to its pedicel, also the berry and skin firmness were statistically higher in samples pretreated with CO2 at 90 - 70% and O3 at 20 ppm in comparison with the control. The skin color parameters and titratable acidity decreased, while, pH increased in all samples in comparison with their initial value. Also, the SSC increased in samples treated with O3 at 20 ppm, CO2 at 70% and dipping. Finally, the sensory evaluation scores gave the decisive data for the selection of the best combination treatments in order to validate their efficiency and that of the film packaging on late season organic table grape "Scarlotta/Sugraninteen". The highest scores for crunchiness, firmness, sweetness and sourness were given to samples pretreated by dipping. In conclusion, the efficiency of both film packaging and MAP inhibited the occurrence of berries decay in all samples including the control. These preliminary results represent the first step to design a treatment approach and develop a postharvest protocol for organic table grapes assigned to long term storage or shipping.

A green and efficient technology for the degradation of cellulosic materials: structure changes and enhanced enzymatic hydrolysis of natural cellulose pretreated by synergistic interaction of mechanical activation and metal salt.

PubMed

Zhang, Yanjuan; Li, Qian; Su, Jianmei; Lin, Ye; Huang, Zuqiang; Lu, Yinghua; Sun, Guosong; Yang, Mei; Huang, Aimin; Hu, Huayu; Zhu, Yuanqin

2015-02-01

A new technology for the pretreatment of natural cellulose was developed, which combined mechanical activation (MA) and metal salt treatments in a stirring ball mill. Different valent metal nitrates were used to investigate the changes in degree of polymerization (DP) and crystallinity index (CrI) of cellulose after MA+metal salt (MAMS) pretreatment, and Al(NO3)3 showed better pretreatment effect than NaNO3 and Zn(NO3)2. The destruction of morphological structure of cellulose was mainly resulted from intense ball milling, and the comparative studies on the changes of DP and crystal structure of MA and MA+Al(NO3)3 pretreated cellulose samples showed a synergistic interaction of MA and Al(NO3)3 treatments with more effective changes of structural characteristics of MA+Al(NO3)3 pretreated cellulose and substantial increase of reducing sugar yield in enzymatic hydrolysis of cellulose. In addition, the results indicated that the presence of Al(NO3)3 had significant enhancement for the enzymatic hydrolysis of cellulose. Copyright © 2014 Elsevier Ltd. All rights reserved.

Enhancement of anaerobic digestion efficiency of wastewater sludge and olive waste: Synergistic effect of co-digestion and ultrasonic/microwave sludge pre-treatment.

PubMed

Alagöz, B Aylin; Yenigün, Orhan; Erdinçler, Ayşen

2015-12-01

This study investigates the effect of ultrasonic and microwave pre-treatment on biogas production from the anaerobic co-digestion of olive pomace and wastewater sludges. It was found that co-digestion of wastewater sludge with olive pomace yielded around 0.21 L CH4/g VS added, whereas the maximum methane yields from the mono-digestion of olive pomace and un-pretreated wastewater sludges were 0.18 and 0.16L CH4/g VS added. In the same way, compared to mono-digestion of these substrates, co-digestion increased methane production by 17-31%. The microwave and ultrasonic pre-treatments applied to sludge samples prior to co-digestion process led to further increase in the methane production by 52% and 24%, respectively, compared to co-digestion with un-pretreated wastewater sludge. The highest biogas and methane yields were obtained from the co-digestion of 30 min microwave pre-treated wastewater sludges and olive pomace to be 0.46 L/g VS added and 0.32 L CH4/g VS added, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Enzymes and chelating agent in cotton pretreatment.

PubMed

Csiszár, E; Losonczi, A; Szakács, G; Rusznák, I; Bezúr, L; Reicher, J

2001-08-23

Desized cotton fabric and cotton seed-coat fragments (impurities) have been treated with commercial cellulase (Celluclast 1.5 L), hemicellulase-pectinase (Viscozyme 120 L) and xylanase (Pulpzyme HC) enzymes. Seed-coat fragments hydrolyzed much faster than the cotton fabric itself. This relative difference in hydrolysis rates makes possible a direct enzymatic removal of seed-coat fragments from desized cotton fabric. Addition of chelating agents such as ethylenediamine-tetra-acetic acid (EDTA) markedly enhanced the directed enzyme action. Pretreatments carried out in acidic solution at pH 5 increased the lightness of seed-coat fragments, contrary to the samples treated in neutral medium at pH 7. Alkaline scouring resulted in darker seed-coat fragments except for the samples pretreated with Pulpzyme HC plus EDTA. This effect is similar to that observed in the biobleaching process in pulp and paper industry.

A Novel Pretreatment-Free Duplex Chamber Digital PCR Detection System for the Absolute Quantitation of GMO Samples.

PubMed

Zhu, Pengyu; Wang, Chenguang; Huang, Kunlun; Luo, Yunbo; Xu, Wentao

2016-03-18

Digital polymerase chain reaction (PCR) has developed rapidly since it was first reported in the 1990s. However, pretreatments are often required during preparation for digital PCR, which can increase operation error. The single-plex amplification of both the target and reference genes may cause uncertainties due to the different reaction volumes and the matrix effect. In the current study, a quantitative detection system based on the pretreatment-free duplex chamber digital PCR was developed. The dynamic range, limit of quantitation (LOQ), sensitivity and specificity were evaluated taking the GA21 event as the experimental object. Moreover, to determine the factors that may influence the stability of the duplex system, we evaluated whether the pretreatments, the primary and secondary structures of the probes and the SNP effect influence the detection. The results showed that the LOQ was 0.5% and the sensitivity was 0.1%. We also found that genome digestion and single nucleotide polymorphism (SNP) sites affect the detection results, whereas the unspecific hybridization within different probes had little side effect. This indicated that the detection system was suited for both chamber-based and droplet-based digital PCR. In conclusion, we have provided a simple and flexible way of achieving absolute quantitation for genetically modified organism (GMO) genome samples using commercial digital PCR detection systems.

A Novel Pretreatment-Free Duplex Chamber Digital PCR Detection System for the Absolute Quantitation of GMO Samples

PubMed Central

Zhu, Pengyu; Wang, Chenguang; Huang, Kunlun; Luo, Yunbo; Xu, Wentao

2016-01-01

Digital polymerase chain reaction (PCR) has developed rapidly since it was first reported in the 1990s. However, pretreatments are often required during preparation for digital PCR, which can increase operation error. The single-plex amplification of both the target and reference genes may cause uncertainties due to the different reaction volumes and the matrix effect. In the current study, a quantitative detection system based on the pretreatment-free duplex chamber digital PCR was developed. The dynamic range, limit of quantitation (LOQ), sensitivity and specificity were evaluated taking the GA21 event as the experimental object. Moreover, to determine the factors that may influence the stability of the duplex system, we evaluated whether the pretreatments, the primary and secondary structures of the probes and the SNP effect influence the detection. The results showed that the LOQ was 0.5% and the sensitivity was 0.1%. We also found that genome digestion and single nucleotide polymorphism (SNP) sites affect the detection results, whereas the unspecific hybridization within different probes had little side effect. This indicated that the detection system was suited for both chamber-based and droplet-based digital PCR. In conclusion, we have provided a simple and flexible way of achieving absolute quantitation for genetically modified organism (GMO) genome samples using commercial digital PCR detection systems. PMID:26999129

Atmospheric corrosion of metals in industrial city environment.

PubMed

Kusmierek, Elzbieta; Chrzescijanska, Ewa

2015-06-01

Atmospheric corrosion is a significant problem given destruction of various materials, especially metals. The corrosion investigation in the industrial city environment was carried out during one year exposure. Corrosion potential was determined using the potentiometric method. The highest effect of corrosion processes was observed during the winter season due to increased air pollution. Corrosion of samples pre-treated in tannic acid before the exposure was more difficult compared with the samples without pretreatment. The corrosion products determined with the SEM/EDS method prove that the most corrosive pollutants present in the industrial city air are SO2, CO2, chlorides and dust.

Biomethane production and physicochemical characterization of anaerobically digested teff (Eragrostis tef) straw pretreated by sodium hydroxide.

PubMed

Chufo, Akiber; Yuan, Hairong; Zou, Dexun; Pang, Yunzhi; Li, Xiujin

2015-04-01

The biogas production potential and biomethane content of teff straw through pretreatment by NaOH was investigated. Different NaOH concentrations (1%, 2%, 4% and 6%) were used for each four solid loadings (50, 65, 80 and 95 g/L). The effects of NaOH as pretreatment factor on the biodegradability of teff straw, changes in main compositions and enhancement of anaerobic digestion were analyzed. The result showed that, using 4% NaOH for pretreatment in 80 g/L solid loading produced 40.0% higher total biogas production and 48.1% higher biomethane content than the untreated sample of teff straw. Investigation of changes in chemical compositions and physical microstructure indicated that there was 4.3-22.1% total lignocellulosic compositions removal after three days pretreatment with NaOH. The results further revealed that NaOH pretreatment changed the structural compositions and lignin network, and improved biogas production from teff straw. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of organosolv and ammonia pretreatments on lignin properties and its inhibition for enzymatic hydrolysis

DOE PAGES

Yoo, Chang Geun; Li, Mi; Meng, Xianzhi; ...

2017-04-05

Lignin offers structural support and protection for plant cell walls; but, it also contributes to biomass recalcitrance and the costs of biofuel production via the biological pathway. Organosolv and ammonia pretreatments have been developed to reduce biomass recalcitrance and improve sugar release performance during enzymatic hydrolysis. It is believed that lignin properties are related to its inhibition on enzymatic hydrolysis; therefore, understanding the characteristics of lignin is a key for effective biomass conversion to biofuels. In this study, an organosolv pretreatment using 60% ethanol with 1.25% H 2SO 4 significantly deconstructed poplar lignin and reduced its molecular weights due tomore » the cleavage of lignin inter-unit linkages. The organosolv pretreatment increased the contents of phenolic OH units and the lignin residue showed a high cellulase maximum adsorption capacity. Ammonia pretreatment with 5% ammonium hydroxide was not as effective as organosolv pretreatment on lignin deconstruction. Organosolv lignin residue had lower lignin S/G ratio than the untreated one. Furthermore, when compared to the organosolv lignin residue and untreated lignin, ammonia lignin residue had a higher cellulase adsorption affinity. In addition, the effects of lignin on cellulose hydrolysis was investigated and the results suggested that the presence of lignin with cellulose substrates reduced cellulose hydrolysis, and its inhibitory effect was primarily determined by the lignin properties after each pretreatment. The organosolv pretreatment resulted in a slightly lower cellulase binding strength (249.7 mL g -1) on poplar lignin than that on untreated samples (261.1 mL g -1), while ammonia lignin residue showed a higher cellulase binding strength (402.8 mL g -1) and had more significant inhibition effect on cellulose hydrolysis. Our results demonstrated that the binding strength significantly affected the lignin-derived inhibition on enzymatic hydrolysis of cellulose in the cellulose-lignin mixtures.« less

Effects of organosolv and ammonia pretreatments on lignin properties and its inhibition for enzymatic hydrolysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoo, Chang Geun; Li, Mi; Meng, Xianzhi

Lignin offers structural support and protection for plant cell walls; but, it also contributes to biomass recalcitrance and the costs of biofuel production via the biological pathway. Organosolv and ammonia pretreatments have been developed to reduce biomass recalcitrance and improve sugar release performance during enzymatic hydrolysis. It is believed that lignin properties are related to its inhibition on enzymatic hydrolysis; therefore, understanding the characteristics of lignin is a key for effective biomass conversion to biofuels. In this study, an organosolv pretreatment using 60% ethanol with 1.25% H 2SO 4 significantly deconstructed poplar lignin and reduced its molecular weights due tomore » the cleavage of lignin inter-unit linkages. The organosolv pretreatment increased the contents of phenolic OH units and the lignin residue showed a high cellulase maximum adsorption capacity. Ammonia pretreatment with 5% ammonium hydroxide was not as effective as organosolv pretreatment on lignin deconstruction. Organosolv lignin residue had lower lignin S/G ratio than the untreated one. Furthermore, when compared to the organosolv lignin residue and untreated lignin, ammonia lignin residue had a higher cellulase adsorption affinity. In addition, the effects of lignin on cellulose hydrolysis was investigated and the results suggested that the presence of lignin with cellulose substrates reduced cellulose hydrolysis, and its inhibitory effect was primarily determined by the lignin properties after each pretreatment. The organosolv pretreatment resulted in a slightly lower cellulase binding strength (249.7 mL g -1) on poplar lignin than that on untreated samples (261.1 mL g -1), while ammonia lignin residue showed a higher cellulase binding strength (402.8 mL g -1) and had more significant inhibition effect on cellulose hydrolysis. Our results demonstrated that the binding strength significantly affected the lignin-derived inhibition on enzymatic hydrolysis of cellulose in the cellulose-lignin mixtures.« less

Specific pretreatments reduce curing period of vanilla (Vanilla planifolia) beans.

PubMed

Sreedhar, R V; Roohie, K; Venkatachalam, L; Narayan, M S; Bhagyalakshmi, N

2007-04-18

With the aiming of reducing the curing period, effects of pretreatments on flavor formation in vanilla beans during accelerated curing at 38 degrees C for 40 days were studied. Moisture loss, change in texture, levels of flavoring compounds, and activities of relevant enzymes were compared among various pretreatments as well as the commercial sample. Use of naphthalene acetic acid (NAA; 5 mg/L) or Ethrel (1%) with blanching pretreatment resulted in 3-fold higher vanillin on the 10th day. Other flavoring compounds-vanillic acid, p-hydroxybenzoic acid, and p-hydroxybenzaldehyde-fluctuated greatly, showing no correlation with the pretreatments. Scarification of beans resulted in nearly 4- and 3.6-fold higher vanillin formations on the 10th day in NAA- and Ethrel-treated beans, respectively, as compared to control with a significant change in texture. When activities of major relevant enzymes were followed, addition of NAA or Ethrel helped to retain higher levels of cellulase throughout the curing period and higher levels of beta-glucosidase on the 20th day that correlated with higher vanillin content during curing and subsequent periods. Peroxidase, being highest throughout, did not correlate with the change in levels of major flavoring compounds. The pretreatment methods of the present study may find importance for realizing higher flavor formation in a shorter period because the major quality parameters were found to be comparable to those of a commercial sample.

Synergy of Siam weed (Chromolaena odorata) and poultry manure for energy generation: Effects of pretreatment methods, modeling and process optimization.

PubMed

Dahunsi, S O; Oranusi, S; Owolabi, J B; Efeovbokhan, V E

2017-02-01

The co-digestion of Chromolaena odorata with poultry manure was evaluated in this study. Two samples of the weed: (A: which was pre-treated with mechanical, chemical and thermal methods) and (B: which was pretreated using mechanical and chemical methods only) were separately digested with poultry manure. Biogas generation started from the 2nd to 4th and 4th to 7th day for samples 'A' and 'B' respectively. The most desired actual biogas yield from samples 'A' and 'B' were 3884.20 and 2544.70 (10 -4 m 3 /kg VS) respectively and the gas composition was 68±2% Methane and 20±2% Carbon dioxide for sample A while it was 62±3% Methane and 22±2% Carbon dioxide for sample B. In all, there was a 38.06% increase in gas generation in 'A' over 'B'. The coefficient of determination (R 2 ) for the Response Surface Methodology (RSM) model (0.9009) was high suggesting high accuracy in the modeling and prediction. The worldwide usage of C. odorata is encouraged. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ozonolysis combined with ultrasound as a pretreatment of sugarcane bagasse: Effect on the enzymatic saccharification and the physical and chemical characteristics of the substrate.

PubMed

Perrone, Olavo Micali; Colombari, Felippe Mariano; Rossi, Jessika Souza; Moretti, Marcia Maria Souza; Bordignon, Sidnei Emilio; Nunes, Christiane da Costa Carreira; Gomes, Eleni; Boscolo, Mauricio; Da-Silva, Roberto

2016-10-01

Sugarcane bagasse (SCB) was treated in three stages using ozone oxidation (O), washing in an alkaline medium (B) and ultrasonic irradiation (U). The impact of each pretreatment stage on the physical structure of the SCB was evaluated by its chemical composition, using an infrared technique (FTIR-ATR), and using thermogravimetric analysis (TGA/DTG). The pretreatment sequence O, B, U provided a significant reduction of lignin and hemicellulose, which was confirmed by changes in the absorption bands corresponding to these compounds, when observed using infrared. Thermogravimetric analysis confirmed an increased thermal stability in the treated sample due to the removal of hemicellulose and extractives during the pretreatment. This pretreatment released 391mg glucose/g from treated SCB after the enzymatic hydrolysis, corresponding to a yield of 94% of the cellulose available. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cardiac effects of magnesium sulfate pretreatment on acute dichlorvos-induced organophosphate poisoning: an experimental study in rats.

PubMed

Gunay, Nurullah; Kekec, Zeynep; Demiryurek, Seniz; Kose, Ataman; Namiduru, Emine S; Gunay, Nahide E; Sari, Ibrahim; Demiryurek, Abdullah T

2010-02-01

Although atropine and oximes are traditionally used in the management of organophosphate poisoning, investigations have been directed to finding additional therapeutic approaches. Thus, the aim of this study was to evaluate the cardiac effects of magnesium sulfate pretreatment on dichlorvos intoxication in rats. Rats were randomly divided into three groups as control, dichlorvos, and magnesium sulfate groups. After 6 h of dichlorvos or corn oil (as a vehicle) injection, venous blood samples were collected, and cardiac tissue samples were obtained. Biochemical analyses were performed to measure some parameters on serum and cardiac tissue. Immunohistochemical analyses of apoptosis and inducible nitric oxide (NO) synthase showed no change in cardiac tissue. Serum cholinesterase levels were markedly depressed with dichlorvos, and further suppressed markedly with magnesium sulfate pretreatment. Although we have demonstrated that serum NO levels in dichlorvos and magnesium sulfate groups were lower than the control group, cardiac tissue NO levels in magnesium sulfate group were higher than the other two groups. Mortality was not significantly affected with magnesium sulfate pretreatment. Uncertainty still persists on the right strategies for the treatment of organophosphate acute poisoning; however, it was concluded that our results do not suggest that magnesium sulfate therapy is beneficial in the management of acute dichlorvos-induced organophosphate poisoning, and also further studies are required.

Microbiological test results using three urine pretreatment regimes with 316L stainless steel

NASA Technical Reports Server (NTRS)

Huff, Timothy L.

1993-01-01

Three urine pretreatments, (1) Oxone (Dupont) and sulfuric acid, (2) sodium hypochlorite and sulfuric acid, (3) and ozone, were studied for their ability to reduce microbial levels in urine and minimize surface attachment to 316L stainless steel coupons. Urine samples inoculated with Bacillus insolitus and a filamentous mold, organisms previously recovered from the vapor compression distillation subsystem of NASA Space Station Freedom water recovery test were tested in glass corrosion cells containing base or weld metal coupons. Microbial levels, changes in pH, color, turbidity, and odor of the fluid were monitored over the course of the 21-day test. Specimen surfaces were examined by scanning electron microscopy at completion of the test for microbial attachment. Ozonated urine samples were less turbid and had lower microbial levels than controls or samples receiving other pretreatments. Base metal coupons receiving pretreatment were relatively free of attached bacteria. However, well-developed biofilms were found in the heat-affected regions of welded coupons receiving Oxone and hypochlorite pretreatments. Few bacteria were observed in the same regions of the ozone pretreatment sample.

Effect of osmotic dehydration pretreatment and glassy state storage on the quality attributes of frozen mangoes under long-term storage.

PubMed

Zhao, Jin-Hong; Xiao, Hong-Wei; Ding, Yang; Nie, Ying; Zhang, Yu; Zhu, Zhen; Tang, Xuan-Ming

2017-05-01

Changes in the quality of frozen mango cuboids were investigated during long-term glassy state storage with and without osmotic dehydration pretreatment. The mango cuboids were dehydrated in mixed solutions (sucrose: glucose: fructose in a ratio of 3.6:1:3) of different concentrations (30, 40, and 50% (wt/wt)) prior to freezing and then stored at -55 °C (in the glassy state) for 6 months. The results revealed that compared with the untreated samples, osmotic pretreatment decreased total color difference (reduced by 15.6-62.3%), drip loss (reduced by 8.2-29.5%) and titration acidity (reduced by 1.3-9.4%), while increasing hardness (increased by 48.8-82.3%), vitamin C content (increased by 72.5-120.6%) and total soluble solids (increased by 21.8-53.7%) of frozen mangoes after 6 months. Dehydration with a sugar concentration of 40% was considered as the optimal pretreatment condition. In addition, a storage temperature of -55 °C provided better retention of quality than rubbery state storage at -18 °C. With prolonged storage time, the quality of frozen mangoes continued to change, even in the glassy state. However, the changes in quality of the osmotic-dehydrated samples were less than those of the untreated samples. The current work indicates that osmotic pretreatment and glassy state storage significantly improved the quality of frozen mangoes during long-term storage.

Pretreatment with low-energy shock waves reduces the renal oxidative stress and inflammation caused by high-energy shock wave lithotripsy.

PubMed

Clark, Daniel L; Connors, Bret A; Handa, Rajash K; Evan, Andrew P

2011-12-01

The purpose of this study was to determine if pretreatment of porcine kidneys with low-energy shock waves (SWs) prior to delivery of a clinical dose of 2,000 SWs reduces or prevents shock wave lithotripsy (SWL)-induced acute oxidative stress and inflammation in the treated kidney. Pigs (7-8 weeks old) received 2,000 SWs at 24 kV (120 SW/min) with or without pretreatment with 100 SWs at 12 kV/2 Hz to the lower pole calyx of one kidney using the HM3. Four hours post-treatment, selected samples of renal tissue were frozen for analysis of cytokine, interleukin-6 (IL-6), and stress response protein, heme oxygenase-1 (HO-1). Urine samples were taken before and after treatment for analysis of tumor necrosis factor-α (TNF-α). Treatment with 2,000 SWs with or without pretreatment caused a statistically significant elevation of HO-1 and IL-6 in the renal medulla localized to the focal zone of the lithotripter. However, the increase in HO-1 and IL-6 was significantly reduced using the pretreatment protocol compared to no pretreatment. Urinary excretion of TNF-α increased significantly (p < 0.05) from baseline for pigs receiving 2,000 SWs alone; however, this effect was completely abolished with the pretreatment protocol. We conclude that pretreatment of the kidney with a low dose of low-energy SWs prior to delivery of a clinical dose of SWs reduces, but does not completely prevent, SWL-induced acute renal oxidative stress and inflammation.

Study of thermal pre-treatment on anaerobic digestion of slaughterhouse waste by TGA-MS and FTIR spectroscopy.

PubMed

Rodríguez-Abalde, Ángela; Gómez, Xiomar; Blanco, Daniel; Cuetos, María José; Fernández, Belén; Flotats, Xavier

2013-12-01

Thermogravimetric analysis coupled to mass spectrometry (TGA-MS) and Fourier-transform infrared spectroscopy (FTIR) were used to describe the effect of pasteurization as a hygienic pre-treatment of animal by-products over biogas production. Piggery and poultry meat wastes were used as substrates for assessing the anaerobic digestion under batch conditions at mesophilic range. Poultry waste was characterized by high protein and carbohydrate content, while piggery waste presented a major fraction of fat and lower carbohydrate content. Results from anaerobic digestion tests showed a lower methane yield for the pre-treated poultry sample. TGA-MS and FTIR spectroscopy allowed the qualitative identification of recalcitrant nitrogen-containing compounds in the pre-treated poultry sample, produced by Maillard reactions. In the case of piggery waste, the recalcitrant compounds were not detected and its biodegradability test reported higher methane yield and production rates. TGA-MS and FTIR spectroscopy were demonstrated to be useful tools for explaining results obtained by anaerobic biodegradability test and in describing the presence of inhibitory problems.

Optimization of Alkaline and Dilute Acid Pretreatment of Agave Bagasse by Response Surface Methodology.

PubMed

Ávila-Lara, Abimael I; Camberos-Flores, Jesus N; Mendoza-Pérez, Jorge A; Messina-Fernández, Sarah R; Saldaña-Duran, Claudia E; Jimenez-Ruiz, Edgar I; Sánchez-Herrera, Leticia M; Pérez-Pimienta, Jose A

2015-01-01

Utilization of lignocellulosic materials for the production of value-added chemicals or biofuels generally requires a pretreatment process to overcome the recalcitrance of the plant biomass for further enzymatic hydrolysis and fermentation stages. Two of the most employed pretreatment processes are the ones that used dilute acid (DA) and alkaline (AL) catalyst providing specific effects on the physicochemical structure of the biomass, such as high xylan and lignin removal for DA and AL, respectively. Another important effect that need to be studied is the use of a high solids pretreatment (≥15%) since offers many advantaged over lower solids loadings, including increased sugar and ethanol concentrations (in combination with a high solids saccharification), which will be reflected in lower capital costs; however, this data is currently limited. In this study, several variables, such as catalyst loading, retention time, and solids loading, were studied using response surface methodology (RSM) based on a factorial central composite design of DA and AL pretreatment on agave bagasse using a range of solids from 3 to 30% (w/w) to obtain optimal process conditions for each pretreatment. Subsequently enzymatic hydrolysis was performed using Novozymes Cellic CTec2 and HTec2 presented as total reducing sugar (TRS) yield. Pretreated biomass was characterized by wet-chemistry techniques and selected samples were analyzed by calorimetric techniques, and scanning electron/confocal fluorescent microscopy. RSM was also used to optimize the pretreatment conditions for maximum TRS yield. The optimum conditions were determined for AL pretreatment: 1.87% NaOH concentration, 50.3 min and 13.1% solids loading, whereas DA pretreatment: 2.1% acid concentration, 33.8 min and 8.5% solids loading.

Optimization of Alkaline and Dilute Acid Pretreatment of Agave Bagasse by Response Surface Methodology

PubMed Central

Ávila-Lara, Abimael I.; Camberos-Flores, Jesus N.; Mendoza-Pérez, Jorge A.; Messina-Fernández, Sarah R.; Saldaña-Duran, Claudia E.; Jimenez-Ruiz, Edgar I.; Sánchez-Herrera, Leticia M.; Pérez-Pimienta, Jose A.

2015-01-01

Utilization of lignocellulosic materials for the production of value-added chemicals or biofuels generally requires a pretreatment process to overcome the recalcitrance of the plant biomass for further enzymatic hydrolysis and fermentation stages. Two of the most employed pretreatment processes are the ones that used dilute acid (DA) and alkaline (AL) catalyst providing specific effects on the physicochemical structure of the biomass, such as high xylan and lignin removal for DA and AL, respectively. Another important effect that need to be studied is the use of a high solids pretreatment (≥15%) since offers many advantaged over lower solids loadings, including increased sugar and ethanol concentrations (in combination with a high solids saccharification), which will be reflected in lower capital costs; however, this data is currently limited. In this study, several variables, such as catalyst loading, retention time, and solids loading, were studied using response surface methodology (RSM) based on a factorial central composite design of DA and AL pretreatment on agave bagasse using a range of solids from 3 to 30% (w/w) to obtain optimal process conditions for each pretreatment. Subsequently enzymatic hydrolysis was performed using Novozymes Cellic CTec2 and HTec2 presented as total reducing sugar (TRS) yield. Pretreated biomass was characterized by wet-chemistry techniques and selected samples were analyzed by calorimetric techniques, and scanning electron/confocal fluorescent microscopy. RSM was also used to optimize the pretreatment conditions for maximum TRS yield. The optimum conditions were determined for AL pretreatment: 1.87% NaOH concentration, 50.3 min and 13.1% solids loading, whereas DA pretreatment: 2.1% acid concentration, 33.8 min and 8.5% solids loading. PMID:26442260

Alcoholic extraction enables EPR analysis to characterize radiation-induced cellulosic signals in spices.

PubMed

Ahn, Jae-Jun; Sanyal, Bhaskar; Akram, Kashif; Kwon, Joong-Ho

2014-11-19

Different spices such as turmeric, oregano, and cinnamon were γ-irradiated at 1 and 10 kGy. The electron paramagnetic resonance (EPR) spectra of the nonirradiated samples were characterized by a single central signal (g = 2.006), the intensity of which was significantly enhanced upon irradiation. The EPR spectra of the irradiated spice samples were characterized by an additional triplet signal at g = 2.006 with a hyperfine coupling constant of 3 mT, associated with the cellulose radical. EPR analysis on various sample pretreatments in the irradiated spice samples demonstrated that the spectral features of the cellulose radical varied on the basis of the pretreatment protocol. Alcoholic extraction pretreatment produced considerable improvements of the EPR signals of the irradiated spice samples relative to the conventional oven and freeze-drying techniques. The alcoholic extraction process is therefore proposed as the most suitable sample pretreatment for unambiguous detection of irradiated spices by EPR spectroscopy.

Construction and field test of a programmable and self-cleaning auto-sampler controlled by a low-cost one-board computer

NASA Astrophysics Data System (ADS)

Stadler, Philipp; Farnleitner, Andreas H.; Zessner, Matthias

2016-04-01

This presentation describes in-depth how a low cost micro-computer was used for substantial improvement of established measuring systems due to the construction and implementation of a purposeful complementary device for on-site sample pretreatment. A fully automated on-site device was developed and field-tested, that enables water sampling with simultaneous filtration as well as effective cleaning procedure of the devicés components. The described auto-sampler is controlled by a low-cost one-board computer and designed for sample pre-treatment, with minimal sample alteration, to meet requirements of on-site measurement devices that cannot handle coarse suspended solids within the measurement procedure or -cycle. The automated sample pretreatment was tested for over one year for rapid and on-site enzymatic activity (beta-D-glucuronidase, GLUC) determination in sediment laden stream water. The formerly used proprietary sampling set-up was assumed to lead to a significant damping of the measurement signal due to its susceptibility to clogging, debris- and bio film accumulation. Results show that the installation of the developed apparatus considerably enhanced error-free running time of connected measurement devices and increased the measurement accuracy to an up-to-now unmatched quality.

Influences of pretreatment and hard baking on the mechanical reliability of SU-8 microstructures

NASA Astrophysics Data System (ADS)

Morikaku, Toshiyuki; Kaibara, Yoshinori; Inoue, Masatoshi; Miura, Takuya; Suzuki, Takaaki; Oohira, Fumikazu; Inoue, Shozo; Namazu, Takahiro

2013-10-01

In this paper, the influences of pretreatment and hard baking on the mechanical characteristics of SU-8 microstructures are described. Four types of samples with different combinations of O2 plasma ashing, primer coating and hard baking were prepared for shear strength tests and uniaxial tensile tests. Specially developed shear test equipment was used to experimentally measure the shear adhesion strength of SU-8 micro posts on a glass substrate. The adhesiveness was strengthened by hard baking at 200 °C for 60 min, whereas other pretreatment processes hardly affected the strength. The pretreatment and hard baking effects on the adhesive strength were compared with those on the fracture strength measured by uniaxial tensile testing. There were no influences of O2 plasma ashing on both the strengths, and primer coating affected only tensile strength. The primer coating effect as well as the hard baking effect on stress relaxation phenomena in uniaxial tension was observed as well. Fourier transform infrared spectroscopy demonstrated that surface degradation and epoxide-ring opening polymerization would have given rise to the primer coating effect and the hard baking effect on the mechanical characteristics, respectively.

Recent advances in the determination of tocopherols in biological fluids: from sample pretreatment and liquid chromatography to clinical studies.

PubMed

Cervinkova, Barbora; Krcmova, Lenka Kujovska; Solichova, Dagmar; Melichar, Bohuslav; Solich, Petr

2016-04-01

Vitamin E comprises eight related compounds: α-, β-, γ-, δ-tocopherols and α-, β-, γ-, δ-tocotrienols. In the past, α-tocopherol has been the isomer that was studied most, and its anti-inflammatory and anti-proliferative effects have been described. Therefore, many prevention trials have investigated the effect of α-tocopherol on human health. Current research studies have also defined the important roles of other tocopherols, such as anti-inflammatory, anti-proliferative and cancer preventative effects. Knowledge of the individual tocopherols could help to understand their roles in various metabolic pathways. This review summarizes the recent trends in sample pretreatment, liquid chromatography and selected applications of the determination of tocopherols in various biological materials. The relationship between tocopherol isomers and serious diseases is also described. Graphical Abstract Article structure.

Effect of Porcelain Surface Pretreatments on Composite Resin-Porcelain Shear Bond Strength

DTIC Science & Technology

1991-05-01

Presented to the Faculty of The University of Texas Graduate School of Biomedical Sciences at San Antonio in Partial Fulfillment of the Requirements...Breckner III The University of Texas Graduate School of Biomedical Sciences at San Antonio Supervising Professor: Barry K. Norling, Ph.D. The bond between...necessary to pretreat the porcelain prior to luting. The samples were not, however, hydrated or thermally stressed . Sheth et al. (1988) supported the

Anaerobic digestion of organic fraction of municipal solid waste combining two pretreatment modalities, high temperature microwave and hydrogen peroxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shahriari, Haleh, E-mail: haleh.shahriari@gmail.com; Warith, Mostafa; Hamoda, Mohamed

2012-01-15

Highlights: Black-Right-Pointing-Pointer Microwave and H{sub 2}O{sub 2} pretreatment were studied to enhance anaerobic digestion of organic waste. Black-Right-Pointing-Pointer The whole waste pretreated at 115 Degree-Sign C or 145 Degree-Sign C had the highest biogas production. Black-Right-Pointing-Pointer Biogas production of the whole waste decreased at 175 Degree-Sign C due to formation of refractory compounds. Black-Right-Pointing-Pointer Pretreatment to 145 Degree-Sign C and 175 Degree-Sign C were the best when considering only the free liquid fraction. Black-Right-Pointing-Pointer H{sub 2}O{sub 2} pretreatment had a lag phase and the biogas production was not higher than MW pretreated samples. - Abstract: In order to enhance anaerobicmore » digestion (AD) of the organic fraction of municipal solid waste (OFMSW), pretreatment combining two modalities, microwave (MW) heating in presence or absence of hydrogen peroxide (H{sub 2}O{sub 2}) were investigated. The main pretreatment variables affecting the characteristics of the OFMSW were temperature (T) via MW irradiation and supplemental water additions of 20% and 30% (SWA20 and SW30). Subsequently, the focus of this study was to evaluate mesophilic batch AD performance in terms of biogas production, as well as changes in the characteristics of the OFMSW post digestion. A high MW induced temperature range (115-175 Degree-Sign C) was applied, using sealed vessels and a bench scale MW unit equipped with temperature and pressure controls. Biochemical methane potential (BMP) tests were conducted on the whole OFMSW as well as the liquid fractions. The whole OFMSW pretreated at 115 Degree-Sign C and 145 Degree-Sign C showed 4-7% improvement in biogas production over untreated OFMSW (control). When pretreated at 175 Degree-Sign C, biogas production decreased due to formation of refractory compounds, inhibiting the digestion. For the liquid fraction of OFMSW, the effect of pretreatment on the cumulative biogas production (CBP) was more pronounced for SWA20 at 145 Degree-Sign C, with a 26% increase in biogas production after 8 days of digestion, compared to the control. When considering the increased substrate availability in the liquid fraction after MW pretreatment, a 78% improvement in biogas production vs. the control was achieved. Combining MW and H{sub 2}O{sub 2} modalities did not have a positive impact on OFMSW stabilization and enhanced biogas production. In general, all samples pretreated with H{sub 2}O{sub 2} displayed a long lag phase and the CBP was usually lower than MW irradiated only samples. First order rate constant was calculated.« less

Low-temperature thermal pre-treatment of municipal wastewater sludge: Process optimization and effects on solubilization and anaerobic degradation.

PubMed

Nazari, Laleh; Yuan, Zhongshun; Santoro, Domenico; Sarathy, Siva; Ho, Dang; Batstone, Damien; Xu, Chunbao Charles; Ray, Madhumita B

2017-04-15

The present study examines the relationship between the degree of solubilization and biodegradability of wastewater sludge in anaerobic digestion as a result of low-temperature thermal pre-treatment. The main effect of thermal pre-treatment is the disintegration of cell membranes and thus solubilization of organic compounds. There is an established correlation between chemical oxygen demand (COD) solubilization and temperature of thermal pre-treatment, but results of thermal pre-treatment in terms of biodegradability are not well understood. Aiming to determine the impact of low temperature treatments on biogas production, the thermal pre-treatment process was first optimized based on an experimental design study on waste activated sludge in batch mode. The optimum temperature, reaction time and pH of the process were determined to be 80 °C, 5 h and pH 10, respectively. All three factors had a strong individual effect (p < 0.001), with a significant interaction effect for temp. pH 2 (p = 0.002). Thermal pre-treatments, carried out on seven different municipal wastewater sludges at the above optimum operating conditions, produced increased COD solubilization of 18.3 ± 7.5% and VSS reduction of 27.7 ± 12.3% compared to the untreated sludges. The solubilization of proteins was significantly higher than carbohydrates. Methane produced in biochemical methane potential (BMP) tests, indicated initial higher rates (p = 0.0013) for the thermally treated samples (k hyd up to 5 times higher), although the ultimate methane yields were not significantly affected by the treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Atmospheric corrosion of metals in industrial city environment

PubMed Central

Kusmierek, Elzbieta; Chrzescijanska, Ewa

2015-01-01

Atmospheric corrosion is a significant problem given destruction of various materials, especially metals. The corrosion investigation in the industrial city environment was carried out during one year exposure. Corrosion potential was determined using the potentiometric method. The highest effect of corrosion processes was observed during the winter season due to increased air pollution. Corrosion of samples pre-treated in tannic acid before the exposure was more difficult compared with the samples without pretreatment. The corrosion products determined with the SEM/EDS method prove that the most corrosive pollutants present in the industrial city air are SO2, CO2, chlorides and dust. PMID:26217736

A pretreatment method for grain size analysis of red mudstones

NASA Astrophysics Data System (ADS)

Jiang, Zaixing; Liu, Li'an

2011-11-01

Traditional sediment disaggregation methods work well for loose mud sediments, but not for tightly cemented mudstones by ferric oxide minerals. In this paper, a new pretreatment method for analyzing the grain size of red mudstones is presented. The experimental samples are Eocene red mudstones from the Dongying Depression, Bohai Bay Basin. The red mudstones are composed mainly of clay minerals, clastic sediments and ferric oxides that make the mudstones red and tightly compacted. The procedure of the method is as follows. Firstly, samples of the red mudstones were crushed into fragments with a diameter of 0.6-0.8 mm in size; secondly, the CBD (citrate-bicarbonate-dithionite) treatment was used to remove ferric oxides so that the cementation of intra-aggregates and inter-aggregates became weakened, and then 5% dilute hydrochloric acid was added to further remove the cements; thirdly, the fragments were further ground with a rubber pestle; lastly, an ultrasonicator was used to disaggregate the samples. After the treatment, the samples could then be used for grain size analysis or for other geological analyses of sedimentary grains. Compared with other pretreatment methods for size analysis of mudstones, this proposed method is more effective and has higher repeatability.

Effect of coagulation on treatment of municipal wastewater reverse osmosis concentrate by UVC/H2O2.

PubMed

Umar, Muhammad; Roddick, Felicity; Fan, Linhua

2014-02-15

Disposal of reverse osmosis concentrate (ROC) is a growing concern due to potential health and ecological risks. Alum coagulation was investigated as pre-treatment for the UVC/H2O2 treatment of two high salinity ROC samples (ROC A and B) of comparable organic and inorganic content. Coagulation removed a greater fraction of the organic content for ROC B (29%) than ROC A (16%) which correlated well with the reductions of colour and A254. Although the total reductions after 60 min UVC/H2O2 treatment with and without coagulation were comparable, large differences in the trends of reduction were observed which were attributed to the different nature of the organic content (humic-like) of the samples as indicated by the LC-OCD analyses and different initial (5% and 16%) biodegradability. Coagulation and UVC/H2O2 treatment preferentially removed humic-like compounds which resulted in low reaction rates after UVC/H2O2 treatment of the coagulated samples. The improvement in biodegradability was greater (2-3-fold) during UVC/H2O2 treatment of the pre-treated samples than without pre-treatment. The target DOC residual (≤ 15 mg/L) was obtained after 30 and 20 min irradiation of pre-treated ROC A and ROC B with downstream biological treatment, corresponding to reductions of 55% and 62%, respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

Evaluation of efficient glucose release using sodium hydroxide and phosphoric acid as pretreating agents from the biomass of Sesbania grandiflora (L.) Pers.: A fast growing tree legume.

PubMed

Mund, Nitesh K; Dash, Debabrata; Barik, Chitta R; Goud, Vaibhav V; Sahoo, Lingaraj; Mishra, Prasannajit; Nayak, Nihar R

2017-07-01

Sesbania grandiflora (L.) Pers. is one of the fast growing tree legumes having the efficiency to produce around 50tha -1 above ground dry matters in a year. In this study, biomass of 2years old S. grandiflora was selected for the chemical composition, pretreatments and enzymatic hydrolysis studies. The stem biomass with a wood density of 3.89±0.01gmcm -3 contains about 38% cellulose, 12% hemicellulose and 28% lignin. Enzymatic hydrolysis of pretreated biomass revealed that phosphoric acid (H 3 PO 4 ) pretreated samples even at lower cellulase loadings [1 Filter Paper Units (FPU)], could efficiently convert about 86% glucose, while, even at higher cellulase loadings (60FPU) alkali pretreated biomass could convert only about 58% glucose. The effectiveness of phosphoric acid pretreatment was also supported by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared spectroscopy (FTIR) analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Enhancement of high-solids enzymatic hydrolysis of corncob residues by bisulfite pretreatment for biorefinery.

PubMed

Xing, Yang; Bu, Lingxi; Zheng, Tianran; Liu, Shijie; Jiang, Jianxin

2016-12-01

Co-production of glucose, furfural and other green materials based on a lignocellulosic biorefinery is a promising way to realize the commercial application of corncob residues. An effective process was developed for glucose production using low temperature bisulfite pretreatment and high-solids enzymatic hydrolysis. Corncob residues from furfural production (FRs) were pretreated with 0.1g NaHSO 3 /g dry substrate at 100°C for 3h. Lignin was sulfonated and sulfonic groups were produced during pretreatment, which resulted in decreasing the zeta potential of the samples. Compared with raw material, bisulfite pretreatment of FRs increased the glucose yield from 18.6 to 99.45% after 72h hydrolysis at a solids loading of 12.5%. The hydrolysis residues showed a relatively high thermal stability and concentrated high derivatives. Direct pretreatment followed by enzymatic hydrolysis is an environmentally-friendly and economically-feasible method for the production of glucose and high-purity lignin, which could be further converted into high-value products. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cellulose pretreatment with 1-n-butyl-3-methylimidazolium chloride for solid acid-catalyzed hydrolysis.

PubMed

Kim, Soo-Jin; Dwiatmoko, Adid Adep; Choi, Jae Wook; Suh, Young-Woong; Suh, Dong Jin; Oh, Moonhyun

2010-11-01

This study has been focused on developing a cellulose pretreatment process using 1-n-butyl-3-methylimidazolium chloride ([bmim]Cl) for subsequent hydrolysis over Nafion(R) NR50. Thus, several pretreatment variables such as the pretreatment period and temperature, and the [bmim]Cl amount were varied. Additionally, the [bmim]Cl-treated cellulose samples were characterized by X-ray diffraction analysis, and their crystallinity index values including CI(XD), CI(XD-CI) and CI(XD-CII) were then calculated. When correlated with these values, the concentrations of total reducing sugars (TRS) obtained by the pretreatment of native cellulose (NC) and glucose produced by the hydrolysis reaction were found to show a distinct relationship with the [CI(NC)-CI(XD)] and CI(XD-CII) values, respectively. Consequently, the cellulose pretreatment step with [bmim]Cl is to loosen a crystalline cellulose through partial transformation of cellulose I to cellulose II and, furthermore, the TRS release, while the subsequent hydrolysis of [bmim]Cl-treated cellulose over Nafion(R) NR50 is effective to convert cellulose II to glucose. Copyright 2010 Elsevier Ltd. All rights reserved.

The correlation between cellulose allomorphs (I and II) and conversion after removal of hemicellulose and lignin of lignocellulose.

PubMed

Song, Yanliang; Zhang, Jingzhi; Zhang, Xu; Tan, Tianwei

2015-10-01

H2SO4, NaOH and H3PO4 were applied to decompose lignocellulose samples (giant reeds, pennisetum and cotton stalks) to investigate the correlation between cellulose allomorphs (cellulose I and II) and conversion of cellulose. The effect of removal of hemicellulose and lignin on the surface morphology, crystallinity index (CrI), cellulose allomorphs (cellulose I and II), and enzymatic hydrolysis under different pretreatments was also studied. CrI caused by H3PO4 pretreatment reached 11.19%, 24.93% and 8.15% for the three samples, respectively. Corn stalk showed highest conversion of cellulose among three samples, irrespective of the pretreatment used. This accounted for the widely use of corn stalk as the renewable crop substrate to synthesize biofuels like ethanol. CrI of cellulose I (CrI-I) negatively affects cellulose conversion but CrI of cellulose II (CrI-II) positively affects cellulose conversion. It contributes to make the strategy to transform cellulose I to cellulose II and enhancing enzymatic hydrolysis of lignocellulose. Copyright © 2015 Elsevier Ltd. All rights reserved.

Understanding the synergistic effect and the main factors influencing the enzymatic hydrolyzability of corn stover at low enzyme loading by hydrothermal and/or ultrafine grinding pretreatment.

PubMed

Zhang, Haiyan; Li, Junbao; Huang, Guangqun; Yang, Zengling; Han, Lujia

2018-05-26

A thorough assessment of the microstructural changes and synergistic effects of hydrothermal and/or ultrafine grinding pretreatment on the subsequent enzymatic hydrolysis of corn stover was performed in this study. The mechanism of pretreatment was elucidated by characterizing the particle size, specific surface area (SSA), pore volume (PV), average pore size, cellulose crystallinity (CrI) and surface morphology of the pretreated samples. In addition, the underlying relationships between the structural parameters and final glucose yields were elucidated, and the relative significance of the factors influencing enzymatic hydrolyzability were assessed by principal component analysis (PCA). Hydrothermal pretreatment at a lower temperature (170 °C) combined with ultrafine grinding achieved a high glucose yield (80.36%) at a low enzyme loading (5 filter paper unit (FPU)/g substrate) which is favorable. The relative significance of structural parameters in enzymatic hydrolyzability was SSA > PV > average pore size > CrI/cellulose > particle size. PV and SSA exhibited logarithmic correlations with the final enzymatic hydrolysis yield. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of pretreatment with dexamethasone or levothyroxine sodium on endotoxin-induced alterations in glucose and insulin dynamics in horses.

PubMed

Tóth, Ferenc; Frank, Nicholas; Geor, Raymond J; Boston, Raymond C

2010-01-01

To investigate the effects of dexamethasone or levothyroxine sodium on endotoxin-induced alterations in glucose and insulin dynamics. 24 horses. Horses were randomly allocated to 3 treatment groups and received 48 mg of levothyroxine mixed with 200 g of oats, 20 mg of dexamethasone plus oats, or oats alone (control) for 15 days, followed by IV infusion of lipopolysaccharide (20 ng/kg) while individually housed in stalls. Frequently sampled IV glucose tolerance tests were performed prior to pretreatment, after pretreatment, and 20 hours after lipopolysaccharide administration. Area under the curve for plasma glucose and serum insulin concentrations was calculated, and minimal model analyses were performed. Significant treatment-by-time effects were detected for insulin sensitivity (SI) and area under the curve for glucose and insulin in the 15-day pretreatment period. Insulin sensitivity significantly decreased over time in all treatment groups, with the largest decrease detected in the dexamethasone group. Administration of lipopolysaccharide further decreased mean SI by 71% and 63% in the dexamethasone and control groups, respectively, but did not affect horses in the levothyroxine group. Mean SI was the lowest in the dexamethasone group, but percentage reduction was the same for dexamethasone and control groups. Insulin sensitivity decreased during the pretreatment period in all 3 groups, indicating that hospitalization affected glucose and insulin dynamics. Dexamethasone significantly lowered SI, and endotoxemia further exacerbated insulin resistance. In contrast, there was no additional effect of endotoxemia on SI in horses pretreated with levothyroxine, suggesting that this treatment prevented endotoxemia-induced insulin resistance.

Effect of phosphate treatments on microbiological, physicochemical changes of spent hen muscle marinated with Tom Yum paste during chilled storage.

PubMed

Wongwiwat, Pirinya; Wattanachant, Saowakon; Siripongvutikorn, Sunisa

2010-06-01

This research aimed to study the effect of phosphate on quality of ready-to-cook spent hen muscle marinated with Tom Yum paste, a famous Thai food made from chilli, lime leaves and garcinia (pH 2.5-2.9). The effects of phosphate treatments (phosphate types, soaking time, and phosphate concentration) on physical characteristics of spent hen muscle in high acid condition were investigated. Quality changes of muscles pretreated with or without phosphate and marinated with Tom Yum paste were determined during storage at 4 degrees C for 30 days. The acidified muscle pretreated with 40 g L(-1) sodium tripolyphosphate for 10 h had the highest marinade absorption, and the lowest cooking loss and shear force among all treatment samples. Microstructures of acidified muscle pretreated with and without sodium tripolyphosphate showed significant swelling with larger fibre diameter. Phosphate pretreatment had no influence on cooking loss, shear force and thiobarbituric acid reactive substance values of Tom Yum marinated muscle during storage. Tom Yum marination with phosphate pretreatment caused a higher increase in psychrophilic bacteria compared to that of marinating without phosphate. Phosphate pretreatment could not improve the physical quality of Tom-Yum marinated spent hen muscle and affected the antimicrobial property of Tom-Yum marinade, resulting in a reduction of shelf-life of the marinated muscle from 30 days to 20 days. Copyright (c) 2010 Society of Chemical Industry.

Rapid-synthesis of zeolite T via sonochemical-assisted hydrothermal growth method.

PubMed

Jusoh, Norwahyu; Yeong, Yin Fong; Mohamad, Maisarah; Lau, Kok Keong; M Shariff, Azmi

2017-01-01

Sonochemical-assisted method has been identified as one of the potential pre-treatment methods which could reduce the formation duration of zeolite as well as other microporous and mesoporous materials. In the present work, zeolite T was synthesized via sonochemical-assisted pre-treatment prior to hydrothermal growth. The durations for sonochemical-assisted pre-treatment were varied from 30min to 90min. Meanwhile, the hydrothermal growth durations were ranged from 0.5 to 3days. The physicochemical properties of the resulting samples were characterized using XRD, FESEM, FTIR and BET. As verified by XRD, the samples synthesized via hydrothermal growth durations of 1, 2 and 3days and sonochemical-assisted pre-treatment durations of 60min and 90min demonstrated zeolite T structure. The samples which underwent sonochemical-assisted pre-treatment duration of 60min yielded higher crystallinity with negligible change of zeolite T morphology. Overall, the lengthy synthesis duration of zeolite T has been successfully reduced from 7days to 1day by applying sonochemical-assisted pre-treatment of 60min, while synthesis duration of 0.5days via sonochemical-assisted pre-treatment of 60min was not sufficient to produce zeolite T structure. Copyright © 2016 Elsevier B.V. All rights reserved.

Improved enzymatic hydrolysis of lignocellulosic biomass through pretreatment with plasma electrolysis.

PubMed

Gao, Jing; Chen, Li; Zhang, Jian; Yan, Zongcheng

2014-11-01

A comprehensive research on plasma electrolysis as pretreatment method for water hyacinth (WH) was performed based on lignin content, crystalline structure, surface property, and enzymatic hydrolysis. A large number of active particles, such as HO and H2O2, generated by plasma electrolysis could decompose the lignin of the biomass samples and reduce the crystalline index. An efficient pretreatment process made use of WH pretreated at a load of 48 wt% (0.15-0.18 mm) in FeCl3 solution for 30 min at 450 V. After the pretreatment, the sugar yield of WH was increased by 126.5% as compared with unpretreated samples. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of electricity generation from ultrasonic and heat/alkaline pretreatment of different sludge types using microbial fuel cells.

PubMed

Oh, Sang-Eun; Yoon, Joung Yee; Gurung, Anup; Kim, Dong-Jin

2014-08-01

This study investigated the effects of different sludge pretreatment methods (ultrasonic vs. combined heat/alkali) with varied sources of municipal sewage sludge (primary sludge (PS), secondary excess sludge (ES), anaerobic digestion sludge (ADS)) on electricity generation in microbial fuel cells (MFCs). Introduction of ultrasonically pretreated sludge (PS, ES, ADS) to MFCs generated maximum power densities of 13.59, 9.78 and 12.67mW/m(2) and soluble COD (SCOD) removal efficiencies of 87%, 90% and 57%, respectively. The sludge pretreated by combined heat/alkali (0.04N NaOH at 120°C for 1h) produced maximum power densities of 10.03, 5.21 and 12.53mW/m(2) and SCOD removal efficiencies of 83%, 75% and 74% with PS, ES and ADS samples, respectively. Higher SCOD by sludge pretreatment enhanced performance of the MFCs and the electricity generation was linearly proportional to the SCOD removal, especially for ES. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparative evaluation of acid and alkaline sulfite pretreatments for enzymatic saccharification of bagasses from three different sugarcane hybrids.

PubMed

Monte, Joseana R; Laurito-Friend, Debora F; Ferraz, André; Milagres, Adriane M F

2018-04-26

Sugarcane bagasses from three experimental sugarcane hybrids and a mill-reference sample were used to compare the efficiency and mode of action of acid and alkaline sulfite pretreatment processes. Varied chemical loads and reaction temperatures were used to prepare samples with distinguished characteristics regarding xylan and lignin removals, as well as sulfonation levels of residual lignins. The pretreatment with low sulfite loads (5%) under acidic conditions (pH 2) provided maximum glucose yield of 70% during enzymatic hydrolysis with cellulases (10 FPU/g) and β-glucosidases (20 UI/g bagasse). In this case, glucan enzymatic conversion from pretreated materials was mostly associated with extensive xylan removal (70-100%) and partial delignification occurred during the pretreatment. The use of low sulfite loads under acidic conditions required pretreatment temperatures of 160°C. In contrast, at a lower pretreatment temperature (120°C), alkaline sulfite process achieved similar glucan digestibility, but required a higher sulfite load (7.5%). Residual xylans from acid pretreated materials were almost completely hydrolysed by commercial enzymes, contrasting with relatively lower xylan to xylose conversions observed in alkaline pretreated samples. Efficient xylan removal during acid sulfite pretreatment and also during enzymatic digestion can be useful to enhance glucan accessibility and digestibility by cellulases. Alkaline sulfite process also provided substrates with high glucan digestibility, mainly associated with delignification and sulfonation of residual lignins. The results demonstrate that temperature, pH and sulfite can be combined for reducing lignocellulose recalcitrance and achieve similar glucan conversion rates in the alkaline and acid sulfite pretreated bagasses. This article is protected by copyright. All rights reserved. © 2018 American Institute of Chemical Engineers.

Impact of contamination and pre-treatment on stable carbon and nitrogen isotopic composition of charred plant remains

PubMed Central

Vaiglova, Petra; Snoeck, Christophe; Nitsch, Erika; Bogaard, Amy; Lee-Thorp, Julia

2014-01-01

Rationale Stable isotope analysis of archaeological charred plants has become a useful tool for interpreting past agricultural practices and refining ancient dietary reconstruction. Charred material that lay buried in soil for millennia, however, is susceptible to various kinds of contamination, whose impact on the grain/seed isotopic composition is poorly understood. Pre-treatment protocols have been adapted in distinct forms from radiocarbon dating, but insufficient research has been carried out on evaluating their effectiveness and necessity for stable carbon and nitrogen isotope analysis. Methods The effects of previously used pre-treatment protocols on the isotopic composition of archaeological and modern sets of samples were investigated. An archaeological sample was also artificially contaminated with carbonates, nitrates and humic acid and subjected to treatment aimed at removing the introduced contamination. The presence and removal of the contamination were investigated using Fourier transform infrared spectroscopy (FTIR) and δ13C and δ15N values. Results The results show a ca 1‰ decrease in the δ15N values of archaeological charred plant material caused by harsh acid treatments and ultra-sonication. This change is interpreted as being caused by mechanical distortion of the grains/seeds rather than by the removal of contamination. Furthermore, specific infrared peaks have been identified that can be used to detect the three types of contaminants studied. We argue that it is not necessary to try to remove humic acid contamination for stable isotope analysis. The advantages and disadvantages of crushing the grains/seeds before pre-treatment are discussed. Conclusions We recommend the use of an acid-only procedure (0.5 M HCl for 30 min at 80°C followed by three rinses in distilled water) for cleaning charred plant remains. This study fills an important gap in plant stable isotope research that will enable future researchers to evaluate potential sources of isotopic change and pre-treat their samples with methods that have been demonstrated to be effective. © 2014 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons Ltd. PMID:25366397

Improvement of the enzymatic hydrolysis of furfural residues by pretreatment with combined green liquor and hydrogen peroxide.

PubMed

Yu, Hai-Long; Tang, Yong; Xing, Yang; Zhu, Li-Wei; Jiang, Jian-Xin

2013-11-01

A potential commercial pretreatment for furfural residues (FRs) was investigated by using a combination of green liquor and hydrogen peroxide (GL-H2O2). The results showed that 56.2% of lignin removal was achieved when the sample was treated with 0.6 g H2O2/g-DS (dry substrate) and 6 mL GL/g-DS at 80 °C for 3 h. After 96 h hydrolysis with 18 FPU/g-cellulose for cellulase, 27 CBU/g-cellulose for β-glucosidase, the glucose yield increased from 71.2% to 83.6%. Ethylenediaminetetraacetic acid was used to reduce the degradation of H2O2, the glucose yield increased to 90.4% after the addition of 1% (w/w). The untreated FRs could bind more easily to cellulase than pretreated FRs could. The structural changes on the surface of sample were characterized by X-ray photoelectron spectroscopy. The results indicated that the surface lignin could be effectively removed during pretreatment, thereby decreasing the enzyme-lignin binding activity. Moreover, the carbonyl from lignin plays an important role in cellulase binding. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of pretreatment with epoxy compounds on the mechanical properties of bovine pericardial bioprosthetic materials.

PubMed

Xi, T; Liu, F; Xi, B

1992-07-01

Early failures of bovine pericardial heart valves are due to leaflet perforation, tearing and calcification. Since glutaraldehyde fixation has been shown to produce marked changes in leaflet mechanics and has been linked to development of calcification, bovine pericardium fixed with the four hydrophilic epoxy formulations and their mechanical properties are studied in this paper. We measured the thicknesses, shrinkage temperatures, stress relaxations and stress-strain curves of bovine pericardiums after different treatments with (1) non-treatment (fresh), (2) glutaraldehyde (GA), (3) epoxy compounds followed by the posttreatment with GA (EP 1#, EP 2#), and (4) epoxy compounds (EP 3# and EP 4#). Results of this study showed that the hydrophilic epoxy compounds are good crosslinking agents. There are no significant differences of shrinkage temperature and ultimate tensile stress among all tissue samples pretreated with GA, EP 1# and EP 2#. However, the stress relaxations of tissue-samples pretreated with epoxy compounds followed by the posttreatment with GA (EP 1# and EP 2#) are significantly slower than that pretreated with GA, and the strains at fracture of EP 1# and EP 2# are also significantly larger than that of GA or epoxy compounds. These facts show that the bovine pericardium pretreated with the epoxy compound followed by the posttreatment with GA (EP 1# and EP 2#) possesses greater tenacity and potential durability in dynamic stress.

Antimutagenic effects of garlic extract on chromosomal aberrations.

PubMed

Shukla, Yogeshwer; Taneja, Pankaj

2002-02-08

Garlic (Allium sativum) has been used since ancient times, as a spice and also for its medicinal properties. In present set of investigations antimutagenic effect of garlic extract (GE) has been evaluated using 'in vivo chromosomal aberration assay' in Swiss albino mice. Cyclophosphamide (CP), a well-known mutagen, was given at a single dose of 25 mg/kg b.w. intraperitoneally. Pretreatment with 1, 2.5 and 5% of freshly prepared GE was given through oral intubation for 5 days prior to CP administration. Animals from all the groups were sacrificed at sampling times of 24 and 48 h and their bone marrow tissue was analyzed for chromosomal damage. The animals of the positive control group (CP alone) shows a significant increase in chromosomal aberrations both at 24 and 48 h sampling time. GE, alone did not significantly induced aberrations at either sampling time, confirming its non-mutagenicity. However in the GE pre-treated and CP post-treated groups, a dose dependent decrease in cytogenetic damage was recorded. A significant suppression in the chromosomal aberrations was recorded following pretreatment with 2.5 and 5% GE administration. The anticytotoxic effects of GE were also evident, as observed by significant increase in mitotic index, when compared to positive control group. Reduction in CP induced clastogenicity by GE was evident at 24 h and to a much greater extent at 48 h of cell cycle. Thus results of the present investigations revealed that GE has chemopreventive potential against CP induced chromosomal mutations in Swiss albino mice.

A comparative study of ultrasonication, Fenton's oxidation and ferro-sonication treatment for degradation of carbamazepine from wastewater and toxicity test by Yeast Estrogen Screen (YES) assay.

PubMed

Mohapatra, D P; Brar, S K; Tyagi, R D; Picard, P; Surampalli, R Y

2013-03-01

A comparative study of ultrasonication (US), Fenton's oxidation (FO) and ferro-sonication (FS) (combination of ultrasonication and Fenton's oxidation) advanced oxidation processes (AOPs) for degradation of carbamazepine (CBZ) from wastewater (WW) is reported for the first time. CBZ is a worldwide used antiepileptic drug, found as a persistent emerging contaminant in many wastewater treatment plants (WWTPs) effluents and other aquatic environments. The oxidation treatments of WW caused an effective removal of the drug. Among the various US, FO and FS pre-treatments carried out, higher soluble chemical oxygen demand (SCOD) and soluble organic carbon (SOC) increment (63 to 86% and 21 to 34%, respectively) was observed during FO pre-treatment process, resulting in higher removal of CBZ (84 to 100%) from WW. Furthermore, analysis of by-products formed during US, FO and FS pre-treatment in WW was carried out by using laser diode thermal desorption-atmospheric pressure chemical ionization (LDTD-APCI) coupled to tandem mass spectrometry (MS/MS). LDTD-APCI-MS/MS analysis indicated formation of two by-products, such as epoxycarbamazepine and hydroxycarbamazepine due to the reaction of hydroxyl radicals (OH) with CBZ during the three types of pre-treatment processes. In addition, the estrogenic activity of US, FO and FS pre-treated sample with CBZ and its by-products was carried out by Yeast Estrogen Screen (YES) assay method. Based upon the YES test results, none of the pre-treated samples showed estrogenic activity. Copyright © 2012 Elsevier B.V. All rights reserved.

Controllable synthesis of (NH4)Fe2(PO4)2(OH)·2H2O using two-step route: Ultrasonic-intensified impinging stream pre-treatment followed by hydrothermal treatment.

PubMed

Dong, Bin; Li, Guang; Yang, Xiaogang; Chen, Luming; Chen, George Z

2018-04-01

(NH 4 )Fe 2 (PO 4 ) 2 (OH)·2H 2 O samples with different morphology are successfully synthesized via two-step synthesis route - ultrasonic-intensified impinging stream pre-treatment followed by hydrothermal treatment (UIHT) method. The effects of the adoption of ultrasonic-intensified impinging stream pre-treatment, reagent concentration (C), pH value of solution and hydrothermal reaction time (T) on the physical and chemical properties of the synthesised (NH 4 )Fe 2 (PO 4 ) 2 (OH)·2H 2 O composites and FePO 4 particles were systematically investigated. Nano-seeds were firstly synthesized using the ultrasonic-intensified T-mixer and these nano-seeds were then transferred into a hydrothermal reactor, heated at 170 °C for 4 h. The obtained samples were characterized by utilising XRD, BET, TG-DTA, SEM, TEM, Mastersizer 3000 and FTIR, respectively. The experimental results have indicated that the particle size and morphology of the obtained samples are remarkably affected by the use of ultrasonic-intensified impinging stream pre-treatment, hydrothermal reaction time, reagent concentration, and pH value of solution. When such (NH 4 )Fe 2 (PO 4 ) 2 (OH)·2H 2 O precursor samples were transformed to FePO 4 products after sintering at 650 °C for 10 h, the SEM images have clearly shown that both the precursor and the final product still retain their monodispersed spherical microstructures with similar particle size of about 3 μm when the samples are synthesised at the optimised condition. Copyright © 2017 Elsevier B.V. All rights reserved.

Anaerobic digestion of organic fraction of municipal solid waste combining two pretreatment modalities, high temperature microwave and hydrogen peroxide.

PubMed

Shahriari, Haleh; Warith, Mostafa; Hamoda, Mohamed; Kennedy, Kevin J

2012-01-01

In order to enhance anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW), pretreatment combining two modalities, microwave (MW) heating in presence or absence of hydrogen peroxide (H(2)O(2)) were investigated. The main pretreatment variables affecting the characteristics of the OFMSW were temperature (T) via MW irradiation and supplemental water additions of 20% and 30% (SWA20 and SW30). Subsequently, the focus of this study was to evaluate mesophilic batch AD performance in terms of biogas production, as well as changes in the characteristics of the OFMSW post digestion. A high MW induced temperature range (115-175°C) was applied, using sealed vessels and a bench scale MW unit equipped with temperature and pressure controls. Biochemical methane potential (BMP) tests were conducted on the whole OFMSW as well as the liquid fractions. The whole OFMSW pretreated at 115°C and 145°C showed 4-7% improvement in biogas production over untreated OFMSW (control). When pretreated at 175°C, biogas production decreased due to formation of refractory compounds, inhibiting the digestion. For the liquid fraction of OFMSW, the effect of pretreatment on the cumulative biogas production (CBP) was more pronounced for SWA20 at 145°C, with a 26% increase in biogas production after 8days of digestion, compared to the control. When considering the increased substrate availability in the liquid fraction after MW pretreatment, a 78% improvement in biogas production vs. the control was achieved. Combining MW and H(2)O(2) modalities did not have a positive impact on OFMSW stabilization and enhanced biogas production. In general, all samples pretreated with H(2)O(2) displayed a long lag phase and the CBP was usually lower than MW irradiated only samples. First order rate constant was calculated. Copyright © 2011 Elsevier Ltd. All rights reserved.

Modeling microbial spoilage and quality of gilthead seabream fillets: combined effect of osmotic pretreatment, modified atmosphere packaging, and nisin on shelf life.

PubMed

Tsironi, Theofania N; Taoukis, Petros S

2010-05-01

The objective of the study was the kinetic modeling of the effect of storage temperature on the quality and shelf life of chilled fish, modified atmosphere-packed (MAP), and osmotically pretreated with the addition of nisin as antimicrobial agent. Fresh gilthead seabream (Sparus aurata) fillets were osmotically treated with 50% high dextrose equivalent maltodextrin (DE 47) plus 5% NaCl. Water loss, solid gain, salt content, and water activity were monitored throughout treatment and treatment conditions were selected for the shelf life study. Untreated and osmotically pretreated slices with and without nisin (2 x 10(4) IU/100 g osmotic solution), packed in air or modified atmosphere (50% CO(2)-50% air), and stored at controlled isothermal conditions (0, 5, 10, and 15 degrees C) were studied. Quality assessment and modeling were based on growth of several microbial indices, total volatile nitrogen, trimethylamine nitrogen, lipid oxidation (TBARS), and sensory scoring. Temperature dependence of quality loss rates was modeled by the Arrhenius equation, validated under dynamic conditions. Pretreated samples showed improved quality stability during subsequent refrigerated storage, in terms of microbial growth, chemical changes, and organoleptic degradation. Osmotic pretreatment with the addition of nisin in combination with MAP was the most effective treatment resulting in significant shelf life extension of gilthead seabream fillets (48 days compared to 10 days for the control at 0 degrees C).

Ozone pretreatment of olive mill wastewaters (OMW) and its effect on OMW biochemical methane potential (BMP).

PubMed

Tsintavi, E; Pontillo, N; Dareioti, M A; Kornaros, M

2013-01-01

The possibility of coupling a physicochemical pretreatment (ozonation) with a biological treatment (anaerobic digestion) was investigated for the case of olive mill wastewaters (OMW). Batch ozonation experiments were performed in a glass bubble reactor. The parameters which were tested included the ozone concentration in the inlet gas stream, the reactor temperature and the composition of the liquid medium in terms of raw or fractionated OMW used. In the sequel, ozone-pretreated OMW samples were tested for their biochemical methane potential (BMP) under mesophilic conditions and these results were compared to the BMP of untreated OMW. The ozonation process alone resulted in a 57-76% decrease of total phenols and a 5-18% decrease of total carbohydrates contained in OMW, depending on the experimental conditions. Nevertheless, the ozone-pretreated OMW exhibited lower chemical oxygen demand removal and methane production during BMP testing compared to the untreated OMW.

Pretreatment of paper tube residuals for improved biogas production.

PubMed

Teghammar, Anna; Yngvesson, Johan; Lundin, Magnus; Taherzadeh, Mohammad J; Horváth, Ilona Sárvári

2010-02-01

Paper tube residuals, which are lignocellulosic wastes, have been studied as substrate for biogas (methane) production. Steam explosion and nonexplosive hydrothermal pretreatment, in combination with sodium hydroxide and/or hydrogen peroxide, have been used to improve the biogas production. The treatment conditions of temperature, time and addition of NaOH and H(2)O(2) were statistically evaluated for methane production. Explosive pretreatment was more successful than the nonexplosive method, and gave the best results at 220 degrees C, 10 min, with addition of both 2% NaOH and 2% H(2)O(2). Digestion of the pretreated materials at these conditions yielded 493 N ml/g VS methane which was 107% more than the untreated materials. In addition, the initial digestion rate was improved by 132% compared to the untreated samples. The addition of NaOH was, besides the explosion effect, the most important factor to improve the biogas production.

The effect of plasma pre-treatment on NaHCO3 desizing of blended sizes on cotton fabrics

NASA Astrophysics Data System (ADS)

Li, Xuming; Qiu, Yiping

2012-03-01

The influence of the He/O2 atmospheric pressure plasma jet pre-treatment on subsequent NaHCO3 desizing of blends of starch phosphate and poly(vinyl alcohol) on cotton fabrics is investigated. Atomic force microscopy and scanning electron microscopy analysis indicate that the surface topography of the samples has significantly changed and the surface roughness increases with an increase in plasma exposure time. X-ray photoelectron spectroscopy analysis shows that a larger number of oxygen-containing polar groups are formed on the sized fabric surface after the plasma treatment. The results of the percent desizing ratio (PDR) indicate that the plasma pretreatment facilitated the blended sizes removal from the cotton fabrics in subsequent NaHCO3 treatment and the PDR increases with prolonging plasma treatment time. The plasma technology is a promising pretreatment for desizing of blended sizes due to dramatically reduced desizing time.

Determination of the acute toxicities of physicochemical pretreatment and advanced oxidation processes applied to dairy effluents on activated sludge.

PubMed

Sivrioğlu, Özge; Yonar, Taner

2015-04-01

In this study, the acute toxicities of raw, physicochemical pre-treated, ozonated, and Fenton reagent applied samples of dairy wastewater toward activated sludge microorganisms, evaluated using the International Organization for Standardization's respiration inhibition test (ISO 8192), are presented. Five-day biological oxygen demand (BOD5) was measured to determine the biodegradability of physicochemical treatment, ozonation, Fenton oxidation or no treatment (raw samples) of dairy wastewater. Chemical pretreatment positively affected biodegradability, and the inhibition exhibited by activated sludge was removed to a considerable degree. Ozonation and the Fenton process exhibited good chemical oxygen demand removal (61%) and removal of toxins. Low sludge production was observed for the Fenton process applied to dairy effluents. We did not determine the inhibitory effect of the Fenton-process on the activated sludge mixture. The pollutant-removal efficiencies of the applied processes and their associated operating costs were determined. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Ionic liquid pretreatment of poplar wood at room temperature: swelling and incorporation of nanoparticles.

PubMed

Lucas, Marcel; Macdonald, Brian A; Wagner, Gregory L; Joyce, Stephen A; Rector, Kirk D

2010-08-01

Lignocellulosic biomass offers economic and environmental advantages over corn starch for biofuels production. However, its fractionation currently requires energy-intensive pretreatments, due to the lignin chemical resistance and complex cell wall structure. Recently, ionic liquids have been used to dissolve biomass at high temperatures. In this study, thin sections of poplar wood were swollen by ionic liquid (1-ethyl-3-methylimidazolium acetate) pretreatment at room temperature. The samples contract when rinsed with deionized water. The controlled expansion and contraction of the wood structure can be used to incorporate enzymes and catalysts deep into the wood structure for improved pretreatments and accelerated cellulose hydrolysis. As a proof of concept, silver and gold nanoparticles of diameters ranging from 20 to 100 nm were incorporated at depths up to 4 mum. Confocal surface-enhanced Raman images at different depths show that a significant number of nanoparticles were incorporated into the pretreated sample, and they remained on the samples after rinsing. Quantitative X-ray fluorescence microanalyses indicate that the majority of nanoparticle incorporation occurs after an ionic liquid pretreatment of less than 1 h. In addition to improved pretreatments, the incorporation of materials and chemicals into wood and paper products enables isotope tracing, development of new sensing, and imaging capabilities.

Effect of species, pretreatments, and drying methods on the functional and pasting properties of high-quality yam flour.

PubMed

Wahab, Bashirat A; Adebowale, Abdul-Rasaq A; Sanni, Silifat A; Sobukola, Olajide P; Obadina, Adewale O; Kajihausa, Olatundun E; Adegunwa, Mojisola O; Sanni, Lateef O; Tomlins, Keith

2016-01-01

The study investigated the functional properties of HQYF (high-quality yam flour) from tubers of four dioscorea species. The tubers were processed into HQYF using two pretreatments (potassium metabisulphite: 0.28%, 15 min; blanching: 70°C, 15 min) and drying methods (cabinet: 60°C, 48 h; sun drying: 3 days). Significant differences (P < 0.05) were observed in pasting characteristics of flours among the four species. The drying method significantly affected only the peak viscosity. The interactive effect of species, pretreatment, and drying methods on the functional properties was significant (P < 0.05) except for emulsification capacity, angle of repose, and least gelation concentration. The significant variation observed in most of the functional properties of the HQYF could contribute significantly to breeding programs of the yam species for diverse food applications. The pastes of flour from Dioscorea dumetorum pretreated with potassium metabisulphite and dried under a cabinet dryer were stable compared to other samples, hence will have better applications in products requiring lower retrogradation during freeze/thaw cycles.

Effect of pre-treatment on physicochemical and structural properties, and the bioaccessibility of β-carotene in sweet potato flour.

PubMed

Trancoso-Reyes, Nalleli; Ochoa-Martínez, Luz A; Bello-Pérez, Luis A; Morales-Castro, Juliana; Estévez-Santiago, Rocío; Olmedilla-Alonso, Begoña

2016-06-01

The aim of this research was to evaluate the effect of microwave or steam pre-treatment of raw sweet potato on physicochemical and microstructural properties, and the bioaccessibility of β-carotene in sweet potato flour. This is the first report on using the in vitro digestion model suitable for food, as proposed in a consensus paper, to assess the bioaccessibility of β-carotene in sweet potato flour. The pre-treatments produced a rearrangement of the flour matrix (starch, protein and non-starch polysaccharides), which was greater by using microwaves (M6) conducting to a greater increase in the phase transition temperatures up to 4.14 °C, while the enthalpy presented the higher reduction (4.49 J/g), both parameters in respect to the control. The resistant starch fraction was not modified, with about 3% in all samples. Microwave (M6) and all the steam pre-treatments showed the higher bioaccessibility of β-carotene. This flour can be used in the development of new products with high β-carotene content. Copyright © 2016 Elsevier Ltd. All rights reserved.

Radiation and chemical pretreatment of cellulosic waste

NASA Astrophysics Data System (ADS)

Chosdu, Rahayu; Hilmy, Nazly; Erizal; Erlinda, T. B.; Abbas, B.

1993-10-01

RADIATION AND CHEMICAL PRETREATMENT OF CELLULOSIC WASTE. Combination pretreatment of cellulosic wastes such as corn stalk, cassava bark and peanut husk were studied using chemical and irradiation of electron beam. The effect of 2 % NaOH and irradiation at the doses of 100, 300 and 500 kGy on the cellulosic wastes were evaluated by measurement of the glucose yield in enzymatic hydrolysis. Irradiation was carried out with an electron beam machine EPS-300 (Energy 300 kev, current 50 mA). The result shows that the glucose yield were higher by increasing of dose irradiation and treated with 2 % of NaOH especially in corn stalk. The glucose yield of corn stalk were 20 % in untreated samples and increases to 43 % after treated with electron beam irradiation at the dose of 500 kGy and 2 % NaOH. Cassava bark and peanut husk show the glucose yield are only 3.5, and 2.5% respectively. The effect of E-beam current in enzymatic hydrolysis of corn stalk, and preliminary studied E-beam radiation pretreatment of cassava bark are also reported.

Bioethanol production from rice husk using different pretreatments and fermentation conditions.

PubMed

Madu, Joshua Osuigwe; Agboola, Bolade Oyeyinka

2018-01-01

Bioethanol is an environmentally friendly alternative to petroleum energy sources. This study evaluated the effects of H 2 O, HCl, NaOH and FeCl 3 pretreated rice husk feedstocks on the production of bioethanol. The pretreatments were carried out using water, 0.1 M HCl, NaOH and FeCl 3 at 121 °C for 15 min, followed by simultaneous saccharification and fermentation (SSF) as well as separate hydrolysis and fermentation (SHF). The raw and pretreated lignocellulosic feedstocks were analyzed using Fourier transform infrared spectroscopy. Saccharification and fermentation were accomplished using Trichoderma reesei cellulase and Saccharomyces cerevisiae , respectively. The products obtained after saccharification and fermentation were collected and analyzed for reducing sugars and ethanol contents using 3,5-dinitrosalicylic acid and high-performance liquid chromatography, respectively. Enzyme hydrolysis of the FeCl 3 and HCl treated samples resulted in hydrolysates containing 3.845 and 3.402 mg/ml glucose equivalent, respectively. In all pretreatments, SSF for each pretreatment produced more ethanol than the SHF method; the FeCl 3 pretreatment gave the highest ethanol yield of 3.011 ± 0.034 and 3.802 ± 0.041% in the SHF and SSF methods, respectively. Utilization of FeCl 3 pretreatment of rice husk is a potential option for bioethanol production in the future.

Cetrorelix suppresses the preovulatory LH surge and ovulation induced by ovulation-inducing factor (OIF) present in llama seminal plasma.

PubMed

Silva, Mauricio E; Smulders, Juan P; Guerra, Monserrat; Valderrama, Ximena P; Letelier, Claudia; Adams, Gregg P; Ratto, Marcelo H

2011-05-30

The purpose of the study was to determine if the effect of llama OIF on LH secretion is mediated by stimulation of the hypothalamus or pituitary gland. Using a 2-by-2 factorial design to examine the effects of OIF vs GnRH with or without a GnRH antagonist, llamas with a growing ovarian follicle greater than or equal to 8 mm were assigned randomly to four groups (n = 7 per group) and a) pre-treated with 1.5 mg of GnRH antagonist (cetrorelix acetate) followed by 1 mg of purified llama OIF, b) pre-treated with 1.5 mg of cetrorelix followed by 50 micrograms of GnRH, c) pre-treated with a placebo (2 ml of saline) followed by 1 mg of purified llama OIF or d) pre-treated with a placebo (2 ml of saline) followed by 50 micrograms of GnRH. Pre-treatment with cetrorelix or saline was given as a single slow intravenous dose 2 hours before intramuscular administration of either GnRH or OIF. Blood samples for LH measurement were taken every 15 minutes from 1.5 hours before to 8 hours after treatment. The ovaries were examined by ultrasonography to detect ovulation and CL formation. Blood samples for progesterone measurement were taken every-other-day from Day 0 (day of treatment) to Day 16. Ovulation rate was not different (P = 0.89) between placebo+GnRH (86%) and placebo+OIF groups (100%); however, no ovulations were detected in llamas pre-treated with cetrorelix. Plasma LH concentrations surged (P < 0.01) after treatment in both placebo+OIF and placebo+GnRH groups, but not in the cetrorelix groups. Maximum plasma LH concentrations and CL diameter profiles did not differ between the placebo-treated groups, but plasma progesterone concentrations were higher (P < 0.05), on days 6, 8 and 12 after treatment, in the OIF- vs GnRH-treated group. Cetrorelix (GnRH antagonist) inhibited the preovulatory LH surge induced by OIF in llamas suggesting that LH secretion is modulated by a direct or indirect effect of OIF on GnRH neurons in the hypothalamus.

The Change of Total Anthocyanins in Blueberries and Their Antioxidant Effect After Drying and Freezing

PubMed Central

Srzednicki, George

2004-01-01

This study examined the effects of freezing, storage, and cabinet drying on the anthocyanin content and antioxidant activity of blueberries (Vaccinium corymbosum L). Fresh samples were stored for two weeks at 5°C while frozen samples were kept for up to three months at −20°C. There were two drying treatments, one including osmotic pretreatment followed by cabinet drying and the other involving only cabinet drying. Total anthocyanins found in fresh blueberries were 7.2 ± 0.5 mg/g dry matter, expressed as cyanidin 3-rutinoside equivalents. In comparison with fresh samples, total anthocyanins in untreated and pretreated dried blueberries were significantly reduced to 4.3 ± 0.1 mg/g solid content, 41% loss, and 3.7 ± 0.2 mg/g solid content, 49% loss, respectively. Osmotic treatment followed by a thermal treatment had a greater effect on anthocyanin loss than the thermal treatment alone. In contrast, the frozen samples did not show any significant decrease in anthocyanin level during three months of storage. Measurement of the antioxidant activity of anthocyanin extracts from blueberries showed there was no significant difference between fresh, dried, and frozen blueberries. PMID:15577185

Stage selection and restricted oviposition period improves cryopreservation of Dipteran embryos

USDA-ARS?s Scientific Manuscript database

Embryos of two dipteran species (Musca domestica, and Lucilia sericata) were assessed for an effective sampling time that would result in the highest post cryopreservation hatch proportion. Additionally, the effects of cryopreservation pretreatment viz. permeabilization, on the embryonic age and the...

Aiming for the complete utilization of sugar-beet pulp: Examination of the effects of mild acid and hydrothermal pretreatment followed by enzymatic digestion

PubMed Central

2011-01-01

Background Biomass use for the production of bioethanol or platform chemicals requires efficient breakdown of biomass to fermentable monosaccharides. Lignocellulosic feedstocks often require physicochemical pretreatment before enzymatic hydrolysis can begin. The optimal pretreatment can be different for different feedstocks, and should not lead to biomass destruction or formation of toxic products. Methods We examined the influence of six mild sulfuric acid or water pretreatments at different temperatures on the enzymatic degradability of sugar-beet pulp (SBP). Results We found that optimal pretreatment at 140°C of 15 minutes in water was able to solubilize 60% w/w of the total carbohydrates present, mainly pectins. More severe treatments led to the destruction of the solubilized sugars, and the subsequent production of the sugar-degradation products furfural, hydroxymethylfurfural, acetic acid and formic acid. The pretreated samples were successfully degraded enzymatically with an experimental cellulase preparation. Conclusions In this study, we found that pretreatment of SBP greatly facilitated the subsequent enzymatic degradation within economically feasible time ranges and enzyme levels. In addition, pretreatment of SBP can be useful to fractionate functional ingredients such as arabinans and pectins from cellulose. We found that the optimal combined severity factor to enhance the enzymatic degradation of SBP was between log R'0 = -2.0 and log R'0 = -1.5. The optimal pretreatment and enzyme treatment solubilized up to 80% of all sugars present in the SBP, including ≥90% of the cellulose. PMID:21627804

Microbiological test results of the environmental control and life support systems vapors compression distillation subsystem recycle tank components following various pretreatment protocols

NASA Technical Reports Server (NTRS)

Huff, Tim

1993-01-01

Microbiological samples were collected from the recycle tank of the vapor compression distillation (VCD) subsystem of the water recovery test at NASA MSFC following a 68-day run. The recycle tank collects rejected urine brine that was pretreated with a commercially available oxidant (Oxone) and sulfuric acid and pumps it back to the processing component of the VCD. Samples collected included a water sample and two swab samples, one from the particulate filter surface and a second from material floating on the surface of the water. No bacteria were recovered from the water sample. Both swab samples contained a spore-forming bacterium, Bacillus insolitus. A filamentous fungus was isolated from the floating material. Approximately 1 month after the pretreatment chemicals were changed to sodium hypochlorite and sulfuric acid, a swab of the particulate filter was again analyzed for microbial content. One fungus was isolated, and spore-forming bacteria were observed. These results indicate the inability of these pretreatments to inhibit surface attachment. The implications of the presence of these organisms are discussed.

Effectiveness of a steam cleaning unit for disinfection in a veterinary hospital.

PubMed

Wood, Cheryl L; Tanner, Benjamin D; Higgins, Laura A; Dennis, Jeffrey S; Luempert, Louis G

2014-12-01

To evaluate whether the application of steam to a variety of surface types in a veterinary hospital would effectively reduce the number of bacteria. 5 surface types. Steam was applied as a surface treatment for disinfection to 18 test sites of 5 surface types in a veterinary hospital. A pretreatment sample was obtained by collection of a swab specimen from the left side of each defined test surface. Steam disinfection was performed on the right side of each test surface, and a posttreatment sample was then collected in the same manner from the treated (right) side of each test surface. Total bacteria for pretreatment and posttreatment samples were quantified by heterotrophic plate counts and for Staphylococcus aureus, Pseudomonas spp, and total coliforms by counts on selective media. Significant reductions were observed in heterotrophic plate counts after steam application to dog runs and dog kennel floors. A significant reduction in counts of Pseudomonas spp was observed after steam application to tub sinks. Bacterial counts were reduced, but not significantly, on most other test surfaces that had adequate pretreatment counts for quantification. Development of health-care-associated infections is of increasing concern in human and veterinary medicine. The application of steam significantly reduced bacterial numbers on a variety of surfaces within a veterinary facility. Steam disinfection may prove to be an alternative or adjunct to chemical disinfection within veterinary practices.

Improved volatile fatty acid and biomethane production from lipid removed microalgal residue (LRμAR) through pretreatment.

PubMed

Suresh, Arumuganainar; Seo, Charles; Chang, Ho Nam; Kim, Yeu-Chun

2013-12-01

Renewable energy from lipid removed microalgal residues (LRμARs) serves as a promising tool for sustainable development of the microalgal biodiesel industry. Hence, in this study, LRμAR from Ettlia sp. was characterized for its physico-biochemical parameters, and applied to various pretreatment to increase the biodegradability and used in batch experiments for the production of volatile fatty acids (VFA) and biomethane. After various pretreatments, the soluble organic matters were increased at a maximum of 82% in total organic matters in alkali-autoclaved sample. In addition, VFA and methane production was enhanced by 30% and 40% in alkali-sonicated and alkali-autoclaved samples, respectively. Methane heating value was recovered at maximum of 6.6 MJ kg(-1)VS in alkali-autoclaved conditions with comparison to non-pretreated samples. The pretreatment remarkably improved LRμAR solubilization and enhanced VFA and biomethane production, which holds immense potential to eventually reduce the cost of algal biodiesel. Copyright © 2013 Elsevier Ltd. All rights reserved.

Compositional and structural changes in Phoenix canariensis and Opuntia ficus-indica with pretreatment: Effects on enzymatic hydrolysis and second generation ethanol production.

PubMed

Udeh, Benard Anayo; Erkurt, Emrah Ahmet

2017-01-01

Two different plants namely Phoenix canariensis and Opuntia ficus-indica were used as substrate for reducing sugar generation and ethanol production. Dilute acid, alkaline and steam explosion were used as pretreatment methods in order to depolymerize lignin and/or hemicellulose and recover cellulose. By using alkaline pretreatment with 2.5% NaOH 71.08% for P. canariensis and 74.61% for O. ficus-indica lignin removal and 81.84% for P. canariensis and 72.66% for O. ficus-indica cellulose recovery yields were obtained. Pretreated materials were hydrolyzed by cellulase with high efficiency (87.0% and 84.5% cellulose conversion yields for P. canariensis and O. ficus-indica) and used as substrate for fermentation. Maximum ethanol production of 15.75g/L and 14.71g/L were achieved from P. canariensis and O. ficus-indica respectively. Structural differences were observed by XRD, FTIR and SEM for untreated, pretreated, hydrolyzed and fermented samples and were highly correlated with compositional analysis results. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thermal pretreatment of a high lignin SSF digester residue to increase its softening point

DOE PAGES

Howe, Daniel; Garcia-Perez, Manuel; Taasevigen, Danny; ...

2016-03-24

Residues high in lignin and ash generated from the simultaneous saccharification and fermentation of corn stover were thermally pretreated in an inert (N 2) atmosphere to study the effect of time and temperature on their softening points. These residues are difficult to feed into gasifiers due to premature thermal degradation and formation of reactive liquids in the feed lines, leading to plugging. The untreated and treated residues were characterized by proximate and ultimate analysis, and then analyzed via TGA, DSC, 13C NMR, Py-GC–MS, CHNO/S, and TMA. Interpretation of the compositional analysis indicates that the weight loss observed during pretreatment ismore » mainly due to the thermal decomposition and volatilization of the hemicelluloses and amorphous cellulose fractions. Fixed carbon increases in the pretreated material, mostly due to a concentration effect rather than the formation of new extra poly-aromatic material. The optimal processing time and temperature to minimize the production of carbonyl groups in the pretreated samples was 300 °C at a time of 30 min. Results showed that the softening point of the material could be increased from 187 °C to 250 °C, and that under the experimental conditions studied, pretreatment temperature plays a more important role than time. The increase in softening point was mainly due to the formation of covalent bonds in the lignin structures and the removal of low molecular weight volatile intermediates.« less

The Impact of Post-Pretreatment Conditioning on Enzyme Accessibility and Water Interactions in Alkali Pretreated Rice Straw

NASA Astrophysics Data System (ADS)

Karuna, Nardrapee

Rice straw, a high-abundance lignocellulosic residue from rice production has tremendous potential as a feedstock for biofuel production in California. In this study, the impact of post-alkali pretreatment conditioning schemes on enzyme saccharification efficiency was examined, particularly focusing on understanding resulting biomass compositional impacts on water interactions with the biomass and enzyme accessibility to the cellulose fraction. Rice straw was pretreated with sodium hydroxide and subsequently washed by two different conditions: 1) by extensive washing with distilled water to reduce the pH to the optimum for cellulases which is pH 5--6, and 2) immediate pH adjustment to pH 5--6 with hydrochloric acid before extensive washing with distilled water. The two post-pretreatment conditions gave significant differences in ash, acid-insoluble lignin, glucan and xylan compositions. Alkali pretreatment improved cellulase digestibility of rice straw, and water washing improved enzymatic digestibility more than neutralization. Hydrolysis reactions with a purified Trichoderma reesei Cel7A, a reducing-end specific cellulase, demonstrated that the differences in saccharification are likely due to differences in the accessibility of the cellulose fraction to the cellulolytic enzymes. Further analyses were conducted to study the mobility of the water associated with the rice straw samples by measuring T2 relaxation times of the water protons by 1H-Nuclear Magnetic Resonance (NMR) relaxometry. Results showed significant changes in water association with the rice straw due to the pretreatment and due to the two different post-pretreatment conditions. Pretreatment increased the amount of water at the surface of the rice straw samples as indicated by increased amplitude of the shortest T2 time peaks in the relaxation spectra. Moreover, the amount of water in the first T2 pool in the water washed sample was significantly greater than in the neutralized sample. These results suggest that the specific surface area of rice straw accessible to water protons was increased by the alkali pretreatment, likely due to solubilization of alkali-soluble components of the cell walls. Post-pretreatment processes resulted in differences in the specific surface area likely due to re-precipitation of alkali solubilized components during neutralization. The T2 relaxation times of the surface water pool in washed and raw rice straw were not significantly different, at 4.4 and 4.5 ms, respectively, but both T2 times were significantly shorter than that of the neutralized and then washed sample, at 5.5 ms. The expectation was that the T2 times of the surface water peaks would reflect differences in surface composition of the rice straw samples. Further analysis of surface composition is necessary to further interpret the shortest T2 times observed in the samples. The T2 spectra of the rice straw samples contained longer T2 time peaks that were interpreted as differences in porosity of the rice straw due to the treatments. Pretreatment caused physical changes to rice straw that impacted water organization (3 peaks to 4 peaks), but the amount of water in the peaks were greater in the washed rice straw than the neutralized rice straw suggesting that water-washed rice straw had more of the larger pores than the neutralized and then washed rice straw. One possible explanation is that the neutralization caused precipitation of alkali solubilized components that filled the volumes of the pores.

Influence of acute bupropion pre-treatment on the effects of intranasal cocaine.

PubMed

Stoops, William W; Lile, Joshua A; Glaser, Paul E A; Hays, Lon R; Rush, Craig R

2012-06-01

The aim of this experiment was to determine the influence of acute bupropion pre-treatment on subject-rated effects and choice of intranasal cocaine versus money. A randomized, within-subject, placebo-controlled, double-blind experiment. An out-patient research unit. Eight cocaine-using adults. Subjects completed nine experimental sessions in which they were pre-treated with 0, 100 or 200 mg oral immediate release bupropion. Ninety minutes later they sampled an intranasal cocaine dose [4 (placebo), 15 or 45 mg] and made six choices between that dose and an alternative reinforcer (US$0.25), available on independent, concurrent progressive ratio schedules. Subjects also completed a battery of subject-rated, performance and physiological measures following the sample doses of cocaine. After 0 mg bupropion, the high dose of cocaine (45 mg) was chosen five of six times on average compared to 2.25 of six choices for placebo cocaine (4 mg) (P < 0.05). Active bupropion reduced choice of 45 mg cocaine to 3.13 (100 mg) or 4.00 (200 mg) out of six drug choices on average. Bupropion also consistently enhanced positive subject-rated effects of cocaine (e.g. good effects; willing to take again) while having no effects of its own. The atypical antidepressant, bupropion, acutely appears to reduce preference for intranasal cocaine versus a small amount of money but to increase reported positive experiences of the drug. © 2011 The Authors, Addiction © 2011 Society for the Study of Addiction.

DSS-induced acute colitis in C57BL/6 mice is mitigated by sulforaphane pre-treatment.

PubMed

Wagner, Anika E; Will, Olga; Sturm, Christine; Lipinski, Simone; Rosenstiel, Philip; Rimbach, Gerald

2013-12-01

The Brassica-derived isothiocyanate sulforaphane (SFN) is known to induce factor erythroid 2-related factor 2 (Nrf2), a transcription factor centrally involved in chemoprevention. Furthermore, SFN exhibits anti-inflammatory properties in vitro and in vivo. However, little is known regarding the anti-inflammatory properties of SFN in severe inflammatory phenotypes. In the present study, we tested if pre-treatment with SFN protects mice from dextran sodium sulphate (DSS)-induced colitis. C57BL/6 mice received either phosphate-buffered saline (control) or 25 mg/kg body weight (BW) SFN per os for 7 days. Subsequently, acute colitis was induced by administering 4% DSS via drinking water for 5 days and BWs, stool consistency and faecal blood loss were recorded. Following endoscopic colonoscopy, mice were sacrificed, the organs excised and spleen weights and colon lengths measured. For histopathological analysis, distal colon samples were fixed in 4% para-formaldehyde, sectioned and stained with hematoxylin/eosin. Inflammatory biomarkers were also measured in distal colon. Treatment with SFN prior to colitis induction significantly minimised both BW loss and the disease activity index compared to control mice. Furthermore, colon lengths in SFN pre-treated mice were significantly longer than in control mice. Both macroscopic and microscopic analysis of the colon revealed attenuated inflammation in SFN pre-treated animals. mRNA analysis of distal colon samples confirmed reduced expression of inflammatory markers and increased expression of Nrf2-dependent genes in SFN pre-treated mice. Our results indicate that pre-treating mice with SFN confers protection from DSS-induced colitis. These protective effects were corroborated macroscopically, microscopically and at the molecular level. © 2013.

Comparison of different pretreatment strategies for enzymatic hydrolysis of wheat and barley straw.

PubMed

Rosgaard, Lisa; Pedersen, Sven; Meyer, Anne S

2007-12-01

In biomass-to-ethanol processes a physico-chemical pretreatment of the lignocellulosic biomass is a critical requirement for enhancing the accessibility of the cellulose substrate to enzymatic attack. This report evaluates the efficacy on barley and wheat straw of three different pretreatment procedures: acid or water impregnation followed by steam explosion versus hot water extraction. The pretreatments were compared after enzyme treatment using a cellulase enzyme system, Celluclast 1.5 L from Trichoderma reesei, and a beta-glucosidase, Novozyme 188 from Aspergillus niger. Barley straw generally produced higher glucose concentrations after enzymatic hydrolysis than wheat straw. Acid or water impregnation followed by steam explosion of barley straw was the best pretreatment in terms of resulting glucose concentration in the liquid hydrolysate after enzymatic hydrolysis. When the glucose concentrations obtained after enzymatic hydrolyses were related to the potential glucose present in the pretreated residues, the highest yield, approximately 48% (g g-1), was obtained with hot water extraction pretreatment of barley straw; this pretreatment also produced highest yields for wheat straw, producing a glucose yield of approximately 39% (g g-1). Addition of extra enzyme (Celluclast 1.5 L+Novozyme 188) during enzymatic hydrolysis resulted in the highest total glucose concentrations from barley straw, 32-39 g L-1, but the relative increases in glucose yields were higher on wheat straw than on barley straw. Maldi-TOF MS analyses of supernatants of pretreated barley and wheat straw samples subjected to acid and water impregnation, respectively, and steam explosion, revealed that the water impregnated + steam-exploded samples gave a wider range of pentose oligomers than the corresponding acid-impregnated samples.

Prophylactic Antioxidant Potential of Gallic Acid in Murine Model of Sepsis

PubMed Central

Maurya, Harikesh; Mangal, Vaishali; Gandhi, Sanjay; Prabhu, Kathiresan; Ponnudurai, Kathiresan

2014-01-01

Present study is to investigate the effect of Gallic acid pretreatment on survival of septic animals and oxidative stress in different organs like lungs, liver, kidney, spleen, and vascular dysfunction of mice. Sepsis was induced by cecal ligation and puncture (CLP) in healthy adult male albino mice (25–30 g) and was divided into 3 groups each consisting of 6 animals, that is, sham-operated (SO group (Group I), SO + sepsis (Group II), and Gallic acid + sepsis (Group III)). Group III animals were pretreated with Gallic acid at the dose rate of 20 mg/kg body weight for 2 days before induction of sepsis. Animals were sacrificed on 8th day and the tissue samples were obtained for further investigation on lipid peroxidation (LPO), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GSH). Gallic acid pretreatment significant (P < 0.05) reduces kidney, spleen, liver, and lungs' malondialdehyde level in septic mice. However, it fails to improve reduced glutathione level in all given organs, while, Gallic acid pretreated mice showed significant improvement in SOD activity of kidney and spleen when compared to septic mice. Finally, the beneficial effects of Gallic acid pretreatment in sepsis are evident from the observations that Gallic acid partially restored SOD and catalase activity and completely reversed lipid peroxidation. Further studies are required to find out the possible mechanisms underlying the beneficial effects of Gallic acid on large population. PMID:25018890

Comparison of aqueous ammonia and dilute acid pretreatment of bamboo fractions: Structure properties and enzymatic hydrolysis.

PubMed

Xin, Donglin; Yang, Zhong; Liu, Feng; Xu, Xueru; Zhang, Junhua

2015-01-01

The effect of two pretreatments methods, aqueous ammonia (SAA) and dilute acid (DA), on the chemical compositions, cellulose crystallinity, morphologic change, and enzymatic hydrolysis of bamboo fractions (bamboo yellow, timber, green, and knot) was compared. Bamboo fractions with SAA pretreatment had better hydrolysability than those with DA pretreatment. High crystallinity index resulted in low hydrolysis yield in the conversion of SAA pretreated bamboo fractions, not DA pretreated fractions. The increase of cellulase loading had modestly positive effect in the hydrolysis of both SAA and DA pretreated bamboo fractions, while supplement of xylanase significantly increased the hydrolysis of the pretreated bamboo fractions, especially after SAA pretreatment. The results indicated that SAA pretreatment was more effective than DA pretreatment in conversion of bamboo fractions, and supplementation of xylanase was necessary in effective conversion of the SAA pretreated fractions into fermentable sugars. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of anatomical fractionation on the enzymatic hydrolysis of acid and alkaline pretreated corn stover.

PubMed

Duguid, K B; Montross, M D; Radtke, C W; Crofcheck, C L; Wendt, L M; Shearer, S A

2009-11-01

Due to concerns with biomass collection systems and soil sustainability there are opportunities to investigate the optimal plant fractions to collect for conversion. An ideal feedstock would require a low severity pretreatment to release a maximum amount of sugar during enzymatic hydrolysis. Corn stover fractions were separated manually and analyzed for glucan, xylan, acid soluble lignin, acid insoluble lignin, and ash composition. The stover fractions were also pretreated with either 0%, 0.4%, or 0.8% NaOH for 2 h at room temperature, washed, autoclaved and saccharified. In addition, dilute sulfuric acid pretreated samples underwent simultaneous saccharification and fermentation (SSF) to ethanol. In general, the two pretreatments produced similar trends with cobs, husks, and leaves responding best to the pretreatments, the tops of stalks responding slightly less, and the bottom of the stalks responding the least. For example, corn husks pretreated with 0.8% NaOH released over 90% (standard error of 3.8%) of the available glucan, while only 45% (standard error of 1.1%) of the glucan was produced from identically treated stalk bottoms. Estimates of the theoretical ethanol yield using acid pretreatment followed by SSF were 65% (standard error of 15.9%) for husks and 29% (standard error of 1.8%) for stalk bottoms. This suggests that integration of biomass collection systems to remove sustainable feedstocks could be integrated with the processes within a biorefinery to minimize overall ethanol production costs.

Optimizing on-farm pretreatment of perennial grasses for fuel ethanol production.

PubMed

Digman, Matthew F; Shinners, Kevin J; Casler, Michael D; Dien, Bruce S; Hatfield, Ronald D; Jung, Hans-Joachim G; Muck, Richard E; Weimer, Paul J

2010-07-01

Switchgrass (Panicum virgatum L.) and reed canarygrass (Phalaris arundinacea L.) were pretreated under ambient temperature and pressure with sulfuric acid and calcium hydroxide in separate experiments. Chemical loadings from 0 to 100g (kg DM)(-1) and durations of anaerobic storage from 0 to 180days were investigated by way of a central composite design at two moisture contents (40% or 60% w.b.). Pretreated and untreated samples were fermented to ethanol by Saccharomyces cerevisiae D5A in the presence of a commercially available cellulase (Celluclast 1.5L) and beta-glucosidase (Novozyme 188). Xylose levels were also measured following fermentation because xylose is not metabolized by S. cerevisiae. After sulfuric acid pretreatment and anaerobic storage, conversion of cell wall glucose to ethanol for reed canarygrass ranged from 22% to 83% whereas switchgrass conversions ranged from 16% to 46%. Pretreatment duration had a positive effect on conversion but was mitigated with increased chemical loadings. Conversions after calcium hydroxide pretreatment and anaerobic storage ranged from 21% to 55% and 18% to 54% for reed canarygrass and switchgrass, respectively. The efficacy of lime pretreatment was found to be highly dependent on moisture content. Moreover, pretreatment duration was only found to be significant for reed canarygrass. Although significant levels of acetate and lactate were observed in the biomass after storage, S. cerevisiae was not found to be inhibited at a 10% solids loading. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Automated extraction of DNA from biological stains on fabric from crime cases. A comparison of a manual and three automated methods.

PubMed

Stangegaard, Michael; Hjort, Benjamin B; Hansen, Thomas N; Hoflund, Anders; Mogensen, Helle S; Hansen, Anders J; Morling, Niels

2013-05-01

The presence of PCR inhibitors in extracted DNA may interfere with the subsequent quantification and short tandem repeat (STR) reactions used in forensic genetic DNA typing. DNA extraction from fabric for forensic genetic purposes may be challenging due to the occasional presence of PCR inhibitors that may be co-extracted with the DNA. Using 120 forensic trace evidence samples consisting of various types of fabric, we compared three automated DNA extraction methods based on magnetic beads (PrepFiler Express Forensic DNA Extraction Kit on an AutoMate Express, QIAsyphony DNA Investigator kit either with the sample pre-treatment recommended by Qiagen or an in-house optimized sample pre-treatment on a QIAsymphony SP) and one manual method (Chelex) with the aim of reducing the amount of PCR inhibitors in the DNA extracts and increasing the proportion of reportable STR-profiles. A total of 480 samples were processed. The highest DNA recovery was obtained with the PrepFiler Express kit on an AutoMate Express while the lowest DNA recovery was obtained using a QIAsymphony SP with the sample pre-treatment recommended by Qiagen. Extraction using a QIAsymphony SP with the sample pre-treatment recommended by Qiagen resulted in the lowest percentage of PCR inhibition (0%) while extraction using manual Chelex resulted in the highest percentage of PCR inhibition (51%). The largest number of reportable STR-profiles was obtained with DNA from samples extracted with the PrepFiler Express kit (75%) while the lowest number was obtained with DNA from samples extracted using a QIAsymphony SP with the sample pre-treatment recommended by Qiagen (41%). Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Standardization and optimization of fluorescence in situ hybridization (FISH) for HER-2 assessment in breast cancer: A single center experience.

PubMed

Bogdanovska-Todorovska, Magdalena; Petrushevska, Gordana; Janevska, Vesna; Spasevska, Liljana; Kostadinova-Kunovska, Slavica

2018-05-20

Accurate assessment of human epidermal growth factor receptor 2 (HER-2) is crucial in selecting patients for targeted therapy. Commonly used methods for HER-2 testing are immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Here we presented the implementation, optimization and standardization of two FISH protocols using breast cancer samples and assessed the impact of pre-analytical and analytical factors on HER-2 testing. Formalin fixed paraffin embedded (FFPE) tissue samples from 70 breast cancer patients were tested for HER-2 using PathVysion™ HER-2 DNA Probe Kit and two different paraffin pretreatment kits, Vysis/Abbott Paraffin Pretreatment Reagent Kit (40 samples) and DAKO Histology FISH Accessory Kit (30 samples). The concordance between FISH and IHC results was determined. Pre-analytical and analytical factors (i.e., fixation, baking, digestion, and post-hybridization washing) affected the efficiency and quality of hybridization. The overall hybridization success in our study was 98.6% (69/70); the failure rate was 1.4%. The DAKO pretreatment kit was more time-efficient and resulted in more uniform signals that were easier to interpret, compared to the Vysis/Abbott kit. The overall concordance between IHC and FISH was 84.06%, kappa coefficient 0.5976 (p < 0.0001). The greatest discordance (82%) between IHC and FISH was observed in IHC 2+ group. A standardized FISH protocol for HER-2 assessment, with high hybridization efficiency, is necessary due to variability in tissue processing and individual tissue characteristics. Differences in the pre-analytical and analytical steps can affect the hybridization quality and efficiency. The use of DAKO pretreatment kit is time-saving and cost-effective.

Innovative UVC light (185 nm) and radio-frequency-plasma pretreatment of Nylon surfaces at atmospheric pressure and their implications in photocatalytic processes.

PubMed

Mejía, M I; Marín, J M; Restrepo, G; Pulgarín, C; Mielczarski, E; Mielczarski, J; Stolitchnov, I; Kiwi, J

2009-10-01

Innovative pretreatment by UVC light (185 nm) and by radio-frequency (RF) plasma at atmospheric pressure to functionalize the Nylon surface, increasing its bondability toward TiO(2), is reported in this study. In the case of UVC light pretreatment in air, the molar absorption coefficient of O(2)/N(2) at 185 nm is very low and the air in the chamber absorbs very little light from the UVC source before reaching the Nylon sample. Nylon fabrics under RF plasma were also functionalized at atmospheric pressure because of the marked heating effect introduced in the Nylon by the RF plasma. This effect leads to intermolecular bond breaking and oxygenated surface groups in the topmost Nylon layers. Both pretreatments enhanced significantly the photocatalytic discoloration of the red-wine stain in Nylon-TiO(2) compared with samples without pretreatment. The UVC and RF methods in the absence of vacuum imply a considerable cost reduction to functionalize textile surfaces, suggesting a potential industrial application. Red-wine-stain discoloration under simulated sunlight was monitored quantitatively by diffuse-reflectance spectroscopy and by CO(2) evolution. X-ray photoelectron spectroscopy (XPS) was used to monitor the changes of the C, N, and S species on the Nylon topmost layers during the discoloration process. Significant changes in the XPS spectra of Ti 2p peaks were observed during discoloration of the wine spots. Wine stains attenuated the signal of the Ti 2p (458.4 eV) peak in the Nylon-TiO(2)-stained wine sample at time zero (from now on, the time before the discoloration process). Furthermore, a decrease of the wine-related O 1s signal at 529.7 eV and N 1s signal at 399.5 eV was observed during the discoloration process, indicating an efficient catalytic decomposition of the wine pigment on Nylon-TiO(2). X-ray diffraction detected the formation of anatase on the Nylon fibers. High-resolution transmission electron microscopy shows the formation of anatase particles with sizes between 8 and 20 nm.

Efficient biomass pretreatment using ionic liquids derived from lignin and hemicellulose

PubMed Central

Socha, Aaron M.; Parthasarathi, Ramakrishnan; Shi, Jian; Pattathil, Sivakumar; Whyte, Dorian; Bergeron, Maxime; George, Anthe; Tran, Kim; Stavila, Vitalie; Venkatachalam, Sivasankari; Hahn, Michael G.; Simmons, Blake A.; Singh, Seema

2014-01-01

Ionic liquids (ILs), solvents composed entirely of paired ions, have been used in a variety of process chemistry and renewable energy applications. Imidazolium-based ILs effectively dissolve biomass and represent a remarkable platform for biomass pretreatment. Although efficient, imidazolium cations are expensive and thus limited in their large-scale industrial deployment. To replace imidazolium-based ILs with those derived from renewable sources, we synthesized a series of tertiary amine-based ILs from aromatic aldehydes derived from lignin and hemicellulose, the major by-products of lignocellulosic biofuel production. Compositional analysis of switchgrass pretreated with ILs derived from vanillin, p-anisaldehyde, and furfural confirmed their efficacy. Enzymatic hydrolysis of pretreated switchgrass allowed for direct comparison of sugar yields and lignin removal between biomass-derived ILs and 1-ethyl-3-methylimidazolium acetate. Although the rate of cellulose hydrolysis for switchgrass pretreated with biomass-derived ILs was slightly slower than that of 1-ethyl-3-methylimidazolium acetate, 90–95% glucose and 70–75% xylose yields were obtained for these samples after 72-h incubation. Molecular modeling was used to compare IL solvent parameters with experimentally obtained compositional analysis data. Effective pretreatment of lignocellulose was further investigated by powder X-ray diffraction and glycome profiling of switchgrass cell walls. These studies showed different cellulose structural changes and differences in hemicellulose epitopes between switchgrass pretreatments with the aforementioned ILs. Our concept of deriving ILs from lignocellulosic biomass shows significant potential for the realization of a “closed-loop” process for future lignocellulosic biorefineries and has far-reaching economic impacts for other IL-based process technology currently using ILs synthesized from petroleum sources. PMID:25136131

TiF(4) and NaF at pH 1.2 but not at pH 3.5 are able to reduce dentin erosion.

PubMed

Wiegand, Annette; Magalhães, Ana Carolina; Sener, Beatrice; Waldheim, Elena; Attin, Thomas

2009-08-01

This study aimed to analyse and compare the protective effect of buffered (pH 3.5) and native (pH 1.2) TiF(4) in comparison to NaF solutions of same pH on dentin erosion. Bovine samples were pretreated with 1.50% TiF(4) or 2.02% NaF (both 0.48M F) solutions, each with a pH of 1.2 and 3.5. The control group received no fluoride pretreatment. Ten samples in each group were eroded with HCl (pH 2.6) for 10x60s. Erosion was analysed by determination of calcium release into the acid. Additionally, the surface and the elemental surface composition were examined by scanning electron microscopy (two samples in each group) and X-ray energy-dispersive spectroscopy in fluoridated but not eroded samples (six samples in each group). Cumulative calcium release (nmol/mm(2)) was statistically analysed by repeated measures ANOVA and one-way ANOVA at t=10min. TiF(4) and NaF at pH 1.2 decreased calcium release significantly, while TiF(4) and NaF at pH 3.5 were not effective. Samples treated with TiF(4) at pH 1.2 showed a significant increase of Ti, while NaF pretreatment increased F concentration significantly. TiF(4) at pH 1.2 led to the formation of globular precipitates occluding dentinal tubules, which could not be observed on samples treated with TiF(4) at pH 3.5. NaF at pH 1.2 but not at pH 3.5 induced the formation of surface precipitates covering dentinal tubules. Dentin erosion can be significantly reduced by TiF(4) and NaF at pH 1.2, but not at pH 3.5.

Effect of microwave hydrolysis on transformation of steroidal hormones during anaerobic digestion of municipal sludge cake.

PubMed

Hamid, Hanna; Eskicioglu, Cigdem

2013-09-15

Fate and removal of 16 steroidal (estrogenic, androgenic and progestogenic) hormones were studied during advanced anaerobic digestion of sludge cake using microwave (MW) pretreatment. Effect of pretreatment temperature (80, 120, 160 °C), operating temperature (mesophilic at 35 ± 2 °C, thermophilic at 55 ± 2 °C) and sludge retention time (SRT: 20, 10, 5 days) were studied employing eight lab-scale semi-continuously fed digesters. To determine the potential effect of MW hydrolysis, hormones were quantified in total (sorbed + soluble) and supernatant (soluble) phases of the digester influent and effluent streams. Seven of 16 hormones were above the method reporting limit (RL) in one or more of the samples. Hormone concentrations in total phase of un-pretreated (control) and pretreated digester feeds ranged in <157-2491 ng/L and <157-749 ng/L, respectively. The three studied factors were found to be statistically significant (95% confidence level) in removal of one or more hormones from soluble and/or total phase. MW hydrolysis of the influent resulted in both release (from sludge matrix) and attenuation of hormones in the soluble phase. Accumulation of estrone (E1) as well as progesterone (Pr) and androstenedione (Ad) in most of the digesters indicated possible microbial transformations among the hormones. Compared to controls, all pretreated digesters had lower total hormone concentrations in their influent streams. At 20 days SRT, highest total removal (E1+E2+Ad +Pr) was observed for the thermophilic control digester (56%), followed by pretreated mesophilic digesters at 120 °C and 160 °C with around 48% efficiency. In terms of conventional performance parameters, relative (to control) improvements of MW pretreated digesters at a 5-d SRT ranged in 98-163% and 57-121%, for volatile solids removal and methane production, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Toxoplasma Gondii and Pre-treatment Protocols for Polymerase Chain Reaction Analysis of Milk Samples: A Field Trial in Sheep from Southern Italy.

PubMed

Vismarra, Alice; Barilli, Elena; Miceli, Maura; Mangia, Carlo; Bacci, Cristina; Brindani, Franco; Kramer, Laura

2017-01-24

Toxoplasmosis is a zoonotic disease caused by the protozoan Toxoplasma gondii. Ingestion of raw milk has been suggested as a risk for transmission to humans. Here the authors evaluated pre-treatment protocols for DNA extraction on T. gondii tachyzoite-spiked sheep milk with the aim of identifying the method that resulted in the most rapid and reliable polymerase chain reaction (PCR) positivity. This protocol was then used to analyse milk samples from sheep of three different farms in Southern Italy, including real time PCR for DNA quantification and PCR-restriction fragment length polymorphism for genotyping. The pre-treatment protocol using ethylenediaminetetraacetic acid and Tris-HCl to remove casein gave the best results in the least amount of time compared to the others on spiked milk samples. One sample of 21 collected from sheep farms was positive on one-step PCR, real time PCR and resulted in a Type I genotype at one locus (SAG3). Milk usually contains a low number of tachyzoites and this could be a limiting factor for molecular identification. Our preliminary data has evaluated a rapid, cost-effective and sensitive protocol to treat milk before DNA extraction. The results of the present study also confirm the possibility of T. gondii transmission through consumption of raw milk and its unpasteurised derivatives.

Investigating effects of sample pretreatment on protein stability using size-exclusion chromatography and high-resolution continuum source atomic absorption spectrometry.

PubMed

Rakow, Tobias; El Deeb, Sami; Hahne, Thomas; El-Hady, Deia Abd; AlBishri, Hassan M; Wätzig, Hermann

2014-09-01

In this study, size-exclusion chromatography and high-resolution atomic absorption spectrometry methods have been developed and evaluated to test the stability of proteins during sample pretreatment. This especially includes different storage conditions but also adsorption before or even during the chromatographic process. For the development of the size exclusion method, a Biosep S3000 5 μm column was used for investigating a series of representative model proteins, namely bovine serum albumin, ovalbumin, monoclonal immunoglobulin G antibody, and myoglobin. Ambient temperature storage was found to be harmful to all model proteins, whereas short-term storage up to 14 days could be done in an ordinary refrigerator. Freezing the protein solutions was always complicated and had to be evaluated for each protein in the corresponding solvent. To keep the proteins in their native state a gentle freezing temperature should be chosen, hence liquid nitrogen should be avoided. Furthermore, a high-resolution continuum source atomic absorption spectrometry method was developed to observe the adsorption of proteins on container material and chromatographic columns. Adsorption to any container led to a sample loss and lowered the recovery rates. During the pretreatment and high-performance size-exclusion chromatography, adsorption caused sample losses of up to 33%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Study of Crystallinity Index (CrI) of Oil Palm Frond Pretreatment using Aqueous [EMIM][OAc] in a Closed System

NASA Astrophysics Data System (ADS)

Abu Darim, R.; Azizan, A.; Salihon, J.

2018-05-01

The objective of this preliminary study is to identify the Crystalinity Index (CrI) of Oil Palm Frond (OPF) pretreated with 40% concentration of 1-ethyl-3-methylimidazolium acetate ionic liquid ([EMIM][OAc]) in a closed system. The morphology and structural changes of the pretreated OPF were examined by using Fourier Transform Infrared Spectrometer (FTIR) and X-Ray Diffraction (XRD). The pretreatment process was carried out in triplicates by loading 40% of [EMIM][OAc] concentration with 10 wt% of OPF loading in the Bio-ionic liquid-reactor. The pretreatment process was conducted for 3 hours with working volume of 70 mL and temperature of 110°C. A Bio-ionic liquid reactor was purposely designed for the lignocellulosic pretreatment by using aqueous ionic liquid at high temperature (higher than boiling point of water). The CrI of OPF pretreated with 40% concentration of [EMM][OAc] in a closed system observed was 9% lower from the untreated OPF and the result showed significant difference with 95% confidence level. Further examination of the untreated and pretreated OPF by using XRD showed that the diffraction pattern of the pretreated OPF samples was decreasing compared to the untreated OPF. The characteristic of the FTIR spectra of the pretreated OPF showed the presence of the cellulose I and occurrence of amorphous cellulosic in the samples. The findings from this study are expected to improve knowledge on pretreatment of OPF by using aqueous [EMIM][OAc] as a green economically viable process for future renewable energy.

Lignocellulose nanofibers prepared by ionic liquid pretreatment and subsequent mechanical nanofibrillation of bagasse powder: Application to esterified bagasse/polypropylene composites.

PubMed

Ninomiya, Kazuaki; Abe, Megumi; Tsukegi, Takayuki; Kuroda, Kosuke; Tsuge, Yota; Ogino, Chiaki; Taki, Kentaro; Taima, Tetsuya; Saito, Joji; Kimizu, Mitsugu; Uzawa, Kiyoshi; Takahashi, Kenji

2018-02-15

In the present study, we examined the efficacy of choline acetate (ChOAc, a cholinium ionic liquid))-assisted pretreatment of bagasse powder for subsequent mechanical nanofibrillation to produce lignocellulose nanofibers. Bagasse sample with ChOAc pretreatment and subsequent nanofibrillation (ChOAc/NF-bagasse) was prepared and compared to untreated control bagasse sample (control bagasse), bagasse sample with nanofibrillation only (NF-bagasse) and with ChOAc pretreatment only (ChOAc-bagasse). The specific surface area was 0.83m 2 /g, 3.1m 2 /g, 6.3m 2 /g, and 32m 2 /g for the control bagasse, ChOAc-bagasse, NF-bagasse, and the ChOAc/NF-bagasse, respectively. Esterified bagasse/polypropylene composites were prepared using the bagasse samples. ChOAc/NF-bagasse exhibited the best dispersion in the composites. The tensile toughness of the composites was 0.52J/cm 3 , 0.73J/cm 3 , 0.92J/cm 3 , and 1.29J/cm 3 for the composites prepared using control bagasse, ChOAc-bagasse, NF-bagasse, and ChOAc/NF-bagasse, respectively. Therefore, ChOAc pretreatment and subsequent nanofibrillation of bagasse powder resulted in enhanced tensile toughness of esterified bagasse/polypropylene composites. Copyright © 2017 Elsevier Ltd. All rights reserved.

The potential value of the seaweed Ceylon moss (Gelidium amansii) as an alternative bioenergy resource.

PubMed

Wi, Seung Gon; Kim, Hyun Joo; Mahadevan, Shobana Arumugam; Yang, Duck-Joo; Bae, Hyeun-Jong

2009-12-01

Sea weed (Ceylon moss) possesses comparable bioenergy production potential to that of land plants. Ceylon moss has high content of carbohydrates, typically galactose (23%) and glucose (20%). We have explored the possibility of sodium chlorite in Ceylon moss pretreatment that can ultimately increase the efficiency of enzymatic saccharification. In an acidic medium, chlorite generates ClO(2) molecules that transform lignin into soluble compounds without any significant loss of carbohydrate content and this procedure is widely used as an analytical method for holocellulose determination. Sodium chlorite-pretreated samples resulted in glucose yield up to 70% with contrast of only 5% was obtained from non-pretreated samples. The efficiency of enzymatic hydrolysis is significantly improved by sodium chlorite pretreatment, and thus sodium chlorite pretreatment is potentially a very useful tool in the utilisation of Ceylon moss biomass for ethanol production or bioenergy purposes.

A Large Sample Evaluation of a Court-Mandated Batterer Intervention Program: Investigating Differential Program Effect for African American and Caucasian Men

ERIC Educational Resources Information Center

Buttell, Frederick P.; Carney, Michelle Mohr

2006-01-01

Objective: The purpose of the present study was to (a) evaluate a 26-week batterer intervention program by investigating changes in psychological variables related to abuse (i.e., truthfulness, violence, lethality, control, alcohol use, drug use, and stress coping abilities) between pretreatment and posttreatment assessments in a large sample of…

Long-term bonding effectiveness of simplified etch-and-rinse adhesives to dentin after different surface pre-treatments

PubMed Central

Verma, Radhika; Singh, Udai Pratap; Tyagi, Shashi Prabha; Nagpal, Rajni; Manuja, Naveen

2013-01-01

Objective: To evaluate the effect of 2% chlorhexidine (CHX) and 30% proanthocyanidin (PA) application on the immediate and long-term bond strength of simplified etch-and-rinse adhesives to dentin. Materials and Methods: One hundred twenty extracted human molar teeth were ground to expose the flat dentin surface. The teeth were equally divided into six groups according to the adhesives used, either Tetric N Bond or Solobond M and pretreatments given either none, CHX, or PA. Composite cylinder was bonded to each specimen using the respective adhesive technique. Half the samples from each group (n = 10) were then tested immediately. The remaining samples were tested after 6 month storage in distilled water. Results: The mean bond strength of samples was not significantly different upon immediate testing being in the range of 8.4(±0.7) MPa. The bond strength fell dramatically in the control specimens after 6 month storage to around 4.7(±0.33) MPa, while the bond strength was maintained in the samples treated with both CHX and PA. Conclusion: Thirty percent PA was comparable to 2% CHX with respect to preservation of the resin dentin bond over 6 months. PMID:23956543

Fatty acids characterization, oxidative perspectives and consumer acceptability of oil extracted from pre-treated chia (Salvia hispanica L.) seeds.

PubMed

Imran, Muhammad; Nadeem, Muhammad; Manzoor, Muhammad Faisal; Javed, Amna; Ali, Zafar; Akhtar, Muhammad Nadeem; Ali, Muhammad; Hussain, Yasir

2016-09-20

Chia (Salvia hispanica L.) seeds have been described as a good source of lipids, protein, dietary fiber, polyphenolic compounds and omega-3 polyunsaturated fatty acids. The consumption of chia seed oil helps to improve biological markers related to metabolic syndrome diseases. The oil yield and fatty acids composition of chia oil is affected by several factors such as pre-treatment method and size reduction practices. Therefore, the main mandate of present investigate was to study the effect of different seed pre-treatments on yield, fatty acids composition and sensory acceptability of chia oil at different storage intervals and conditions. Raw chia seeds were characterized for proximate composition. Raw chia seeds after milling were passed through sieves to obtain different particle size fractions (coarse, seed particle size ≥ 10 mm; medium, seed particle size ≥ 5 mm; fine, seed particle size ≤ 5 mm). Heat pre-treatment of chia seeds included the water boiling (100 C°, 5 min), microwave roasting (900 W, 2450 MHz, 2.5 min), oven drying (105 ± 5 °C, 1 h) and autoclaving (121 °C, 15 lbs, 15 min) process. Extracted oil from pre-treated chia seeds were stored in Tin cans at 25 ± 2 °C and 4 ± 1 °C for 60-days and examined for physical (color, melting point, refractive index), oxidative (iodine value, peroxide value, free fatty acids), fatty acids (palmitic, stearic, oleic, linoleic, α-linolenic) composition and sensory (appearance, flavor, overall acceptability) parameters, respectively. The proximal composition of chia seeds consisted of 6.16 ± 0.24 % moisture, 34.84 ± 0.62 % oil, 18.21 ± 0.45 % protein, 4.16 ± 0.37 % ash, 23.12 ± 0.29 % fiber, and 14.18 ± 0.23 % nitrogen contents. The oil yield as a result of seed pre-treatments was found in the range of 3.43 ± 0.22 % (water boiled samples) to 32.18 ± 0.34 % (autoclaved samples). The oil samples at day 0 indicated the maximum color (R and Y Lovibond scale) value for oven drying while at storage day 60 (25 ± 2 °C), the highest color value was found for autoclave pre-treatment. The slightly increasing trend of color values for all treatments was observed during the storage period. The lowest iodine value (182.83 ± 1.18 g/100 g at storage day 0 & 173.49 ± 1.21 g/100 g at storage day 60, 25 ± 2 °C) was calculated for autoclaved samples while the maximum iodine value (193.42 ± 1.14 g/100 g at storage day 0 & 190.36 ± 1.17 g/100 g at storage day 60, 25 ± 2 °C) was recorded for raw chia samples. The significant increasing trend for all treatments was observed in case of peroxide value and free fatty acids production during storage. Maximum decrease in linoleic (35 %) and α-linolenic (18 %) fatty acids was observed in autoclaved samples. The oil from pre-treated seed samples obtained decreasing scores for sensory parameters throughout the storage period at different conditions. As a result, chia seeds are an important source of lipids and essential fatty acids. The water boiling and high temperature processing of chia seeds provides instability to lipids during storage at room temperature. However, detailed investigation is required on the processing performance and storage stability of food products supplemented with pre-treated chia seeds and furthers their effect on biological system.

Improved sugar yields from biomass sorghum feedstocks: comparing low-lignin mutants and pretreatment chemistries.

PubMed

Godin, Bruno; Nagle, Nick; Sattler, Scott; Agneessens, Richard; Delcarte, Jérôme; Wolfrum, Edward

2016-01-01

For biofuel production processes to be economically efficient, it is essential to maximize the production of monomeric carbohydrates from the structural carbohydrates of feedstocks. One strategy for maximizing carbohydrate production is to identify less recalcitrant feedstock cultivars by performing some type of experimental screening on a large and diverse set of candidate materials, or by identifying genetic modifications (random or directed mutations or transgenic plants) that provide decreased recalcitrance. Economic efficiency can also be increased using additional pretreatment processes such as deacetylation, which uses dilute NaOH to remove the acetyl groups of hemicellulose prior to dilute acid pretreatment. In this work, we used a laboratory-scale screening tool that mimics relevant thermochemical pretreatment conditions to compare the total sugar yield of three near-isogenic brown midrib ( bmr ) mutant lines and the wild-type (WT) sorghum cultivar. We then compared results obtained from the laboratory-scale screening pretreatment assay to a large-scale pretreatment system. After pretreatment and enzymatic hydrolysis, the bmr mutants had higher total sugar yields than the WT sorghum cultivar. Increased pretreatment temperatures increased reactivity for all sorghum samples reducing the differences observed at lower reaction temperatures. Deacetylation prior to dilute acid pretreatment increased the total sugar yield for all four sorghum samples, and reduced the differences in total sugar yields among them, but solubilized a sizable fraction of the non-structural carbohydrates. The general trends of increased total sugar yield in the bmr mutant compared to the WT seen at the laboratory scale were observed at the large-scale system. However, in the larger reactor system, the measured total sugar yields were lower and the difference in total sugar yield between the WT and bmr sorghum was larger. Sorghum bmr mutants, which have a reduced lignin content showed higher total sugar yields than the WT cultivar after dilute acid pretreatment and enzymatic hydrolysis. Deacetylation prior to dilute acid pretreatment increased the total sugar yield for all four sorghum samples. However, since deacetylation also solubilizes a large fraction of the non-structural carbohydrates, the ability to derive value from these solubilized sugars will depend greatly on the proposed conversion process.

Improved sugar yields from biomass sorghum feedstocks: comparing low-lignin mutants and pretreatment chemistries

DOE PAGES

Godin, Bruno; Nagle, Nick; Sattler, Scott; ...

2016-11-21

For biofuel production processes to be economically efficient, it is essential to maximize the production of monomeric carbohydrates from the structural carbohydrates of feedstocks. One strategy for maximizing carbohydrate production is to identify less recalcitrant feedstock cultivars by performing some type of experimental screening on a large and diverse set of candidate materials, or by identifying genetic modifications (random or directed mutations or transgenic plants) that provide decreased recalcitrance. Economic efficiency can also be increased using additional pretreatment processes such as deacetylation, which uses dilute NaOH to remove the acetyl groups of hemicellulose prior to dilute acid pretreatment. In thismore » work, we used a laboratory-scale screening tool that mimics relevant thermochemical pretreatment conditions to compare the total sugar yield of three near-isogenic brown midrib (bmr) mutant lines and the wild-type (WT) sorghum cultivar. We then compared results obtained from the laboratory-scale screening pretreatment assay to a large-scale pretreatment system. After pretreatment and enzymatic hydrolysis, the bmr mutants had higher total sugar yields than the WT sorghum cultivar. Increased pretreatment temperatures increased reactivity for all sorghum samples reducing the differences observed at lower reaction temperatures. Deacetylation prior to dilute acid pretreatment increased the total sugar yield for all four sorghum samples, and reduced the differences in total sugar yields among them, but solubilized a sizable fraction of the non-structural carbohydrates. The general trends of increased total sugar yield in the bmr mutant compared to the WT seen at the laboratory scale were observed at the large-scale system. However, in the larger reactor system, the measured total sugar yields were lower and the difference in total sugar yield between the WT and bmr sorghum was larger. Sorghum bmr mutants, which have a reduced lignin content showed higher total sugar yields than the WT cultivar after dilute acid pretreatment and enzymatic hydrolysis. In conclusion, deacetylation prior to dilute acid pretreatment increased the total sugar yield for all four sorghum samples. However, since deacetylation also solubilizes a large fraction of the non-structural carbohydrates, the ability to derive value from these solubilized sugars will depend greatly on the proposed conversion process.« less

Improved sugar yields from biomass sorghum feedstocks: comparing low-lignin mutants and pretreatment chemistries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Godin, Bruno; Nagle, Nick; Sattler, Scott

For biofuel production processes to be economically efficient, it is essential to maximize the production of monomeric carbohydrates from the structural carbohydrates of feedstocks. One strategy for maximizing carbohydrate production is to identify less recalcitrant feedstock cultivars by performing some type of experimental screening on a large and diverse set of candidate materials, or by identifying genetic modifications (random or directed mutations or transgenic plants) that provide decreased recalcitrance. Economic efficiency can also be increased using additional pretreatment processes such as deacetylation, which uses dilute NaOH to remove the acetyl groups of hemicellulose prior to dilute acid pretreatment. In thismore » work, we used a laboratory-scale screening tool that mimics relevant thermochemical pretreatment conditions to compare the total sugar yield of three near-isogenic brown midrib (bmr) mutant lines and the wild-type (WT) sorghum cultivar. We then compared results obtained from the laboratory-scale screening pretreatment assay to a large-scale pretreatment system. After pretreatment and enzymatic hydrolysis, the bmr mutants had higher total sugar yields than the WT sorghum cultivar. Increased pretreatment temperatures increased reactivity for all sorghum samples reducing the differences observed at lower reaction temperatures. Deacetylation prior to dilute acid pretreatment increased the total sugar yield for all four sorghum samples, and reduced the differences in total sugar yields among them, but solubilized a sizable fraction of the non-structural carbohydrates. The general trends of increased total sugar yield in the bmr mutant compared to the WT seen at the laboratory scale were observed at the large-scale system. However, in the larger reactor system, the measured total sugar yields were lower and the difference in total sugar yield between the WT and bmr sorghum was larger. Sorghum bmr mutants, which have a reduced lignin content showed higher total sugar yields than the WT cultivar after dilute acid pretreatment and enzymatic hydrolysis. In conclusion, deacetylation prior to dilute acid pretreatment increased the total sugar yield for all four sorghum samples. However, since deacetylation also solubilizes a large fraction of the non-structural carbohydrates, the ability to derive value from these solubilized sugars will depend greatly on the proposed conversion process.« less

Treatment of textile dyehouse effluent using ceramic membrane based process in combination with chemical pretreatment.

PubMed

Bhattacharya, Priyankari; Ghosh, Sourja; Majumdar, Swachchha; Bandyopadhyay, Sibdas

2013-10-01

Treatment of highly concentrated dyebath effluent and comparatively dilute composite effluent having mixture of various reactive dyes collected from a cotton fabric dyeing unit was undertaken in the present study. Ceramic microfiltration membrane prepared from a cost effective composition of alumina and clay was used. Prior to microfiltration, a chemical pretreatment was carried out with aluminium sulphate in combination with a polymeric retention aid. An optimum dose of 100 mg/L of aluminium sulphate and 1 ml/L of a commercial flocculant Afilan RAMF was found effective for dye removal (> 98%) from the synthetic solutions of reactive dyes with initial concentration of 150 mg/L in both the single component and two component systems. In the microfiltration study, effect of operating pressure in the permeate flux was observed for both the pretreated and untreated effluents and permeate samples were analyzed for dye concentration, COD, turbidity, TSS, etc. during constant pressure filtration. About 98-99% removal of dyes was obtained in the combined process with COD reduction of 54-64%.

Characterization of Lignin Streams during Bionic Liquid-Based Pretreatment from Grass, Hardwood, and Softwood

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dutta, Tanmoy; Papa, Gabriella; Wang, Eileen

Delignification as a function of ionic liquid (IL) pretreatment has potential in terms of recovering and converting the fractionated lignin streams to renewable products. Renewable biogenic ionic liquids, or bionic liquids (eg. cholinium lysinate, ([Ch][Lys])), provide opportunities in terms of effective, economic and sustainable lignocellulosic biomass pretreatment. We have evaluated [Ch][Lys] pretreatment in terms of sugar and lignin yields for three different feedstocks: switchgrass, eucalyptus, and pine. Four lignin streams isolated during [Ch][Lys] pretreatment and enzymatic hydrolysis were comprehensively analyzed, tracking their changes in physical-chemical structures. We observed changes in major lignin linkages and lignin aromatics units (p-hydroxyphenyl (H), guaiacylmore » (G), and syringil (S)) that occurred during pretreatment. A compositional analysis of the different process streams and a comprehensive mass balance in conjunction with multiple analytical techniques (Nuclear Magnetic Resonance (NMR), Mass Spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR), Gel Permeation Chromatography (GPC)) is presented. Qualitative and quantitative analyses indicates that there are significantly more lignin-carbohydrate interactions for G-rich lignin in pine. The lignin removal and extent of lignin depolymerization for switchgrass and eucalyptus were higher than pine, and follows the order of switchgrass > eucalyptus > pine. The recovered lignin from pretreated liquid contained a lower relative amount of carbohydrate signals than raw biomass, indicating a high degree of dissociation of lignin carbohydrate complex (LCC) linkages for all samples analyzed. The insights gained from this work contribute to better understanding of physiochemical properties of lignin streams generated during [Ch][Lys] pretreatment, offering a starting point for lignin valorization strategies.« less

Evaluations of cellulose accessibilities of lignocelluloses by solute exclusion and protein adsorption techniques

Treesearch

Q.Q. Wang; Z. He; Z. Zhu; Y.-H.P. Zhang; Y. Ni; X.L. Luo; J.Y. Zhu

2012-01-01

Cellulose accessibilities of a set of hornified lignocellulosic substrates derived by drying the never dried pretreated sample and a set of differently pretreated lodgepople pine substrates, were evaluated using solute exclusion and protein adsorption methods. Direct measurements of cellulase adsorption onto cellulose surface of the set of pretreated substrates were...

AIR DRYING AND PRETREATMENT EFFECTS ON SOIL SULFATE SORPTION

EPA Science Inventory

Drying, freezing, and refrigeration are commonly employed to facilitate the handling and storage of soil samples on which chemical, biological and physical analyses are to be performed. hese laboratory protocol have the potential to alter soil chemical characteristics and may res...

A laboratory-scale pretreatment and hydrolysis assay for determination of reactivity in cellulosic biomass feedstocks.

PubMed

Wolfrum, Edward J; Ness, Ryan M; Nagle, Nicholas J; Peterson, Darren J; Scarlata, Christopher J

2013-11-14

The rapid determination of the release of structural sugars from biomass feedstocks is an important enabling technology for the development of cellulosic biofuels. An assay that is used to determine sugar release for large numbers of samples must be robust, rapid, and easy to perform, and must use modest amounts of the samples to be tested.In this work we present a laboratory-scale combined pretreatment and saccharification assay that can be used as a biomass feedstock screening tool. The assay uses a commercially available automated solvent extraction system for pretreatment followed by a small-scale enzymatic hydrolysis step. The assay allows multiple samples to be screened simultaneously, and uses only ~3 g of biomass per sample. If the composition of the biomass sample is known, the results of the assay can be expressed as reactivity (fraction of structural carbohydrate present in the biomass sample released as monomeric sugars). We first present pretreatment and enzymatic hydrolysis experiments on a set of representative biomass feedstock samples (corn stover, poplar, sorghum, switchgrass) in order to put the assay in context, and then show the results of the assay applied to approximately 150 different feedstock samples covering 5 different materials. From the compositional analysis data we identify a positive correlation between lignin and structural carbohydrates, and from the reactivity data we identify a negative correlation between both carbohydrate and lignin content and total reactivity. The negative correlation between lignin content and total reactivity suggests that lignin may interfere with sugar release, or that more mature samples (with higher structural sugars) may have more recalcitrant lignin. The assay presented in this work provides a robust and straightforward method to measure the sugar release after pretreatment and saccharification that can be used as a biomass feedstock screening tool. We demonstrated the utility of the assay by identifying correlations between feedstock composition and reactivity in a population of 150 samples.

Ultrasound pretreatment of filamentous algal biomass for enhanced biogas production.

PubMed

Lee, Kwanyong; Chantrasakdakul, Phrompol; Kim, Daegi; Kong, Mingeun; Park, Ki Young

2014-06-01

The filamentous alga Hydrodictyon reticulatum harvested from a bench-scale wastewater treatment pond was used to evaluate biogas production after ultrasound pretreatment. The effects of ultrasound pretreatment at a range of 10-5000 J/mL were tested with harvested H. reticulatum. Cell disruption by ultrasound was successful and showed a higher degree of disintegration at a higher applied energy. The range of 10-5000 J/mL ultrasound was able to disintegrated H. reticulatum and the soluble COD was increased from 250 mg/L to 1000 mg/L at 2500 J/mL. The disintegrated algal biomass was digested for biogas production in batch experiments. Both cumulative gas generation and volatile solids reduction data were obtained during the digestion. Cell disintegration due to ultrasound pretreatment increased the specific biogas production and degradation rates. Using the ultrasound approach, the specific methane production at a dose of 40 J/mL increased up to 384 mL/g-VS fed that was 2.3 times higher than the untreated sample. For disintegrated samples, the volatile solids reduction was greater with increased energy input, and the degradation increased slightly to 67% at a dose of 50 J/mL. The results also indicate that disintegration of the algal cells is the essential step for efficient anaerobic digestion of algal biomass. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of thermal pre-treatment on the availability of PAHs for successive chemical oxidation in contaminated soils.

PubMed

Usman, M; Chaudhary, A; Biache, C; Faure, P; Hanna, K

2016-01-01

This is the premier study designed to evaluate the impact of thermal pre-treatment on the availability of polycyclic aromatic hydrocarbons (PAHs) for successive removal by chemical oxidation. Experiments were conducted in two soils having different PAH distribution originating from former coking plant sites (Homécourt, H, and Neuves Maisons, NM) located in northeast of France. Soil samples were pre-heated at 60, 100, and 150 °C for 1 week under inert atmosphere (N2). Pre-heating resulted in slight removal of PAHs (<10%) and loss of extractable organic matter (EOM). Then, these pre-heated soil samples were subjected to Fenton-like oxidation (H2O2 and magnetite) at room temperature. Chemical oxidation in soil without any pre-treatment showed almost no PAH degradation underscoring the unavailability of PAHs. However, chemical oxidation in pre-heated soils showed significant PAH degradation (19, 29, and 43% in NM soil and 31, 36, and 47% in H soil pre-treated at 60, 100, and 150 °C, respectively). No preferential removal of PAHs was observed after chemical oxidation in both soils. These results indicated the significant impact of pre-heating temperature on the availability of PAHs in contaminated soils and therefore may have strong implications in the remediation of contaminated soils especially where pollutant availability is a limiting factor.

The effect of biomass densification on structural sugar release and yield in biofuel feedstock and feedstock blends

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolfrum, Edward J.; Nagle, Nicholas J.; Ness, Ryan M.

In this work, we examined the behavior of feedstock blends and the effect of a specific feedstock densification strategy (pelleting) on the release and yield of structural carbohydrates in a laboratory-scale dilute acid pretreatment (PT) and enzymatic hydrolysis (EH) assay. We report overall carbohydrate release and yield from the two-stage PT-EH assay for five single feedstocks (two corn stovers, miscanthus, switchgrass, and hybrid poplar) and three feedstock blends (corn stover-switchgrass, corn stover-switchgrass-miscanthus, and corn stover-switchgrass-hybrid poplar). We first examined the experimental results over time to establish the robustness of the PT-EH assay, which limits the precision of the experimental results.more » The use of two different control samples in the assay enabled us to identify (and correct for) a small bias in the EH portion of the combined assay for some runs. We then examined the effect of variable pretreatment reaction conditions (residence time, acid loading, and reactor temperature) on the conversion of a single feedstock (single-pass corn stover, CS-SP) in order to establish the range of pretreatment reaction conditions likely to provide optimal conversion data. Finally, we applied the assay to the 16 materials (8 feedstocks in 2 formats, loose and pelleted) over a more limited range of pretreatment experimental conditions. The four herbaceous feedstocks behaved similarly, while the hybrid poplar feedstock required higher pretreatment temperatures for optimal results. As expected, the yield data for three blended feedstocks were the average of the yield data for the individual feedstocks. As a result, the pelleting process appears to provide a slightly positive effect on overall total sugar yield.« less

The effect of biomass densification on structural sugar release and yield in biofuel feedstock and feedstock blends

DOE PAGES

Wolfrum, Edward J.; Nagle, Nicholas J.; Ness, Ryan M.; ...

2017-01-13

In this work, we examined the behavior of feedstock blends and the effect of a specific feedstock densification strategy (pelleting) on the release and yield of structural carbohydrates in a laboratory-scale dilute acid pretreatment (PT) and enzymatic hydrolysis (EH) assay. We report overall carbohydrate release and yield from the two-stage PT-EH assay for five single feedstocks (two corn stovers, miscanthus, switchgrass, and hybrid poplar) and three feedstock blends (corn stover-switchgrass, corn stover-switchgrass-miscanthus, and corn stover-switchgrass-hybrid poplar). We first examined the experimental results over time to establish the robustness of the PT-EH assay, which limits the precision of the experimental results.more » The use of two different control samples in the assay enabled us to identify (and correct for) a small bias in the EH portion of the combined assay for some runs. We then examined the effect of variable pretreatment reaction conditions (residence time, acid loading, and reactor temperature) on the conversion of a single feedstock (single-pass corn stover, CS-SP) in order to establish the range of pretreatment reaction conditions likely to provide optimal conversion data. Finally, we applied the assay to the 16 materials (8 feedstocks in 2 formats, loose and pelleted) over a more limited range of pretreatment experimental conditions. The four herbaceous feedstocks behaved similarly, while the hybrid poplar feedstock required higher pretreatment temperatures for optimal results. As expected, the yield data for three blended feedstocks were the average of the yield data for the individual feedstocks. As a result, the pelleting process appears to provide a slightly positive effect on overall total sugar yield.« less

Metabonomics study of the effects of pretreatment with glycyrrhetinic acid on mesaconitine-induced toxicity in rats.

PubMed

Sun, Bo; Zhang, Ming; Zhang, Qi; Ma, Kunpeng; Li, Haijing; Li, Famei; Dong, Fangting; Yan, Xianzhong

2014-07-03

Aconitum carmichaelii Debx. (Fuzi), a commonly use traditional Chinese medicine (TCM), has often been used in combination with Rhizoma Glycyrrhizae (Gancao) to reduce its toxicity due to diester diterpenoid alkaloids aconitine, mesaconitine, and hypaconitine. However, the mechanism of detoxication is still unclear. Glycyrrhetinic acid (GA) is the metabolite of glycyrrhizinic acid (GL), the major component of Gancao. In present study, the effect of GA on the changes of metabolic profiles induced by mesaconitine was investigated using NMR-based metabolomic approaches. Fifteen male Wistar rats were divided into a control group, a group administered mesaconitine alone, and a group administered mesaconitine with one pretreatment with GA. Their urine samples were used for NMR spectroscopic metabolic profiling. Statistical analyses such as orthogonal projections to latent structures-discriminant analysis (OPLS-DA), t-test, hierarchical cluster, and pathway analysis were used to detect the effects of pretreatment with GA on mesaconitine-induced toxicity. The OPLS-DA score plots showed the metabolic profiles of GA-pretreated rats apparently approach to those of normal rats compared to mesaconitine-induced rats. From the t-test and boxplot results, the concentrations of leucine/isoleucine, lactate, acetate, succinate, trimethylamine (TMA), dimethylglycine (DMG), 2-oxo-glutarate, creatinine/creatine, glycine, hippurate, tyrosine and benzoate were significantly changed in metabolic profiles of mesaconitine-induced rats. The disturbed metabolic pathways include amino acid biosynthesis and metabolism. GA-pretreatment can mitigate the metabolic changes caused by mesaconitine-treatment on rats, indicating that prophylaxis with GA could reduce the toxicity of mesaconitine at the metabolic level. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Characterization of halogenated DBPs and identification of new DBPs trihalomethanols in chlorine dioxide treated drinking water with multiple extractions.

PubMed

Han, Jiarui; Zhang, Xiangru; Liu, Jiaqi; Zhu, Xiaohu; Gong, Tingting

2017-08-01

Chlorine dioxide (ClO 2 ) is a widely used alternative disinfectant due to its high biocidal efficiency and low-level formation of trihalomethanes and haloacetic acids. A major portion of total organic halogen (TOX), a collective parameter for all halogenated DBPs, formed in ClO 2 -treated drinking water is still unknown. A commonly used pretreatment method for analyzing halogenated DBPs in drinking water is one-time liquid-liquid extraction (LLE), which may lead to a substantial loss of DBPs prior to analysis. In this study, characterization and identification of polar halogenated DBPs in a ClO 2 -treated drinking water sample were conducted by pretreating the sample with multiple extractions. Compared to one-time LLE, the combined four-time LLEs improved the recovery of TOX by 2.3 times. The developmental toxicity of the drinking water sample pretreated with the combined four-time LLEs was 1.67 times higher than that pretreated with one-time LLE. With the aid of ultra-performance liquid chromatography/electrospray ionization-triple quadrupole mass spectrometry, a new group of polar halogenated DBPs, trihalomethanols, were detected in the drinking water sample pretreated with multiple extractions; two of them, trichloromethanol and bromodichloromethanol, were identified with synthesized standard compounds. Moreover, these trihalomethanols were found to be the transformation products of trihalomethanes formed during ClO 2 disinfection. The results indicate that multiple LLEs can significantly improve extraction efficiencies of polar halogenated DBPs and is a better pretreatment method for characterizing and identifying new polar halogenated DBPs in drinking water. Copyright © 2017. Published by Elsevier B.V.

ECLSS Sustaining Compatibility Testing on Urine Processor Assembly Nonmetallic Materials for Reformulation of Pretreated Urine Solution

NASA Technical Reports Server (NTRS)

Wingard, C. D.

2015-01-01

On International Space Station (ISS), the Urine Processor Assembly (UPA) converts human urine and flush water into potable water. The urine is acid-pretreated primarily to control microbial growth. In recent years, the sulfuric acid (H2SO4) pretreatment was believed to be largely responsible for producing salt crystals capable of plugging filters in UPA components and significantly reducing the percentage of water recovery from urine. In 2012, ISS management decided to change the acid pretreatment for urine from sulfuric to phosphoric with the goal of eliminating or minimizing formation of salt crystals. In 2013-2014, as part of the qualification of the phosphoric acid (H3PO4) formulation, samples of 12 nonmetallic materials used in UPA components were immersed for up to one year in pretreated urine and brine solutions made with the new H3PO4 formulation. Dynamic mechanical analysis (DMA) was used to measure modulus (stiffness) of the immersed samples compared to virgin control samples. Such compatibility data obtained by DMA for the H3PO4-based solutions were compared to DMA data obtained for the H2SO4-based solutions in 2002-2003.

Alkaline organosolv pretreatment of corn stover for enhancing the enzymatic digestibility.

PubMed

Yuan, Wei; Gong, Zhiwei; Wang, Guanghui; Zhou, Wenting; Liu, Yi; Wang, Xuemin; Zhao, Mi

2018-06-14

In the present study, a sodium hydroxide-methanol solution (SMs) pretreatment of corn stover was described to overcome biomass recalcitrance for the first time. Effects of sodium hydroxide loading, solid-to-liquid ratio, processing time and temperature on enzymatic saccharification were studied in detail. The SMs pretreatment could significantly enhance the enzyme accessibility of corn stover, minimize the degradation of sugar polymers, and decrease the energy consumption. 97.5% glucan and 83.5% xylan were preserved in the regenerated corn stover under the optimal condition. Subsequent enzymatic digestibilities of glucan and xylan reached 97.2% and 80.3%, respectively. The enzyme susceptibility of the regenerated samples was explained by their physical and chemical characteristics. This strategy provides a promising alternative for better techno-economic of the lignocelluloses-to-sugars routes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Combining hot-compressed water and ball milling pretreatments to improve the efficiency of the enzymatic hydrolysis of eucalyptus

PubMed Central

Inoue, Hiroyuki; Yano, Shinichi; Endo, Takashi; Sakaki, Tsuyoshi; Sawayama, Shigeki

2008-01-01

Background Lignocellulosic biomass such as wood is an attractive material for fuel ethanol production. Pretreatment technologies that increase the digestibility of cellulose and hemicellulose in the lignocellulosic biomass have a major influence on the cost of the subsequent enzymatic hydrolysis and ethanol fermentation processes. Pretreatments without chemicals such as acids, bases or organic solvents are less effective for an enzymatic hydrolysis process than those with chemicals, but they have a less negative effect on the environment. Results The enzymatic digestibility of eucalyptus was examined following a combined pretreatment without chemicals comprising a ball milling (BM) and hot-compressed water (HCW) treatment. The BM treatment simultaneously improved the digestibility of both glucan and xylan, and was effective in lowering the enzyme loading compared with the HCW treatment. The combination of HCW and BM treatment reduced the BM time. The eucalyptus treated with HCW (160°C, 30 minutes) followed by BM (20 minutes) had an approximately 70% yield of total sugar with a cellulase loading of 4 FPU/g substrate. This yield was comparable to the yields from samples treated with HCW (200°C, 30 minutes) or BM (40 minutes) hydrolyzed with 40 FPU/g substrate. Conclusion The HCW treatment is useful in improving the milling efficiency. The combined HCW-BM treatment can save energy and enzyme loading. PMID:18471309

The effect of pre-treatment and modified atmosphere packaging on contents of phenolic compounds and sensory and microbiological quality of shredded celeriac.

PubMed

Radziejewska-Kubzdela, Elżbieta; Czapski, Janusz; Czaczyk, Katarzyna; Biegańska-Marecik, Róża

2014-04-01

The aim of this study was to determine the effect of washing (4 °C, 120 s) or soaking (4 °C, 600 s) of shredded celeriac in tap water on changes in contents of phenolic compounds, including furanocoumarins, and sensory and microbiological quality during 12 days of storage. The product was packaged in air or modified atmosphere containing 2/10/88 kPa O2/CO2/N2. The applied pre-treatment consisting of washing or soaking of shredded celeriac in water resulted in decreases in 8-methoxypsoralen content by approximately 50 and 70% respectively and phenolic content by 30% compared with samples that were not subjected to pre-treatment. During storage of shredded celeriac, a further significant (P ≤ 0.05) reduction in phenolic compounds and an approximately 2.5-fold increase in the total content of furanocoumarins were found. The application of modified atmosphere packaging had a significant effect on the maintenance of good sensory and microbiological quality of the tested product. Modified atmosphere packaging of shredded celeriac not subjected to pre-treatment made it possible to obtain a product with good sensory and microbiological quality and the highest content of phenolic compounds. The level of furanocoumarins recorded in the tested product does not constitute a health hazard. © 2013 Society of Chemical Industry.

Using Propensity Scores for Estimating Causal Effects: A Study in the Development of Moral Reasoning

ERIC Educational Resources Information Center

Grunwald, Heidi E.; Mayhew, Matthew J.

2008-01-01

The purpose of this study was to illustrate the use of propensity scores for creating comparison groups, partially controlling for pretreatment course selection bias, and estimating the treatment effects of selected courses on the development of moral reasoning in undergraduate students. Specifically, we used a sample of convenience for comparing…

Chemical and morphological characterization of sugarcane bagasse submitted to a delignification process for enhanced enzymatic digestibility

PubMed Central

2011-01-01

Background In recent years, biorefining of lignocellulosic biomass to produce multi-products such as ethanol and other biomaterials has become a dynamic research area. Pretreatment technologies that fractionate sugarcane bagasse are essential for the successful use of this feedstock in ethanol production. In this paper, we investigate modifications in the morphology and chemical composition of sugarcane bagasse submitted to a two-step treatment, using diluted acid followed by a delignification process with increasing sodium hydroxide concentrations. Detailed chemical and morphological characterization of the samples after each pretreatment condition, studied by high performance liquid chromatography, solid-state nuclear magnetic resonance, diffuse reflectance Fourier transformed infrared spectroscopy and scanning electron microscopy, is reported, together with sample crystallinity and enzymatic digestibility. Results Chemical composition analysis performed on samples obtained after different pretreatment conditions showed that up to 96% and 85% of hemicellulose and lignin fractions, respectively, were removed by this two-step method when sodium hydroxide concentrations of 1% (m/v) or higher were used. The efficient lignin removal resulted in an enhanced hydrolysis yield reaching values around 100%. Considering the cellulose loss due to the pretreatment (maximum of 30%, depending on the process), the total cellulose conversion increases significantly from 22.0% (value for the untreated bagasse) to 72.4%. The delignification process, with consequent increase in the cellulose to lignin ratio, is also clearly observed by nuclear magnetic resonance and diffuse reflectance Fourier transformed infrared spectroscopy experiments. We also demonstrated that the morphological changes contributing to this remarkable improvement occur as a consequence of lignin removal from the sample. Bagasse unstructuring is favored by the loss of cohesion between neighboring cell walls, as well as by changes in the inner cell wall structure, such as damaging, hole formation and loss of mechanical resistance, facilitating liquid and enzyme access to crystalline cellulose. Conclusions The results presented herewith show the efficiency of the proposed method for improving the enzymatic digestibility of sugarcane bagasse and provide understanding of the pretreatment action mechanism. Combining the different techniques applied in this work warranted thorough information about the undergoing morphological and chemical changes and was an efficient approach to understand the morphological effects resulting from sample delignification and its influence on the enhanced hydrolysis results. PMID:22122978

Perform Tests and Document Results and Analysis of Oxide Layer Effects and Comparisons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Collins, E. D.; DelCul, G. D.; Spencer, B. B.

2014-08-30

During the initial feasibility test using actual used nuclear fuel (UNF) cladding in FY 2012, an incubation period of 30–45 minutes was observed in the initial dry chlorination. The cladding hull used in the test had been previously oxidized in a dry air oxidation pretreatment prior to removal of the fuel. The cause of this incubation period was attributed to the resistance to chlorination of an oxide layer imparted by the dry oxidation pretreatment on the cladding. Subsequently in 2013, researchers at the Korea Atomic Energy Institute (KAERI) reported on their chlorination study [R1] on ~9-gram samples of unirradiated ZirloTMmore » cladding tubes that had been previously oxidized in air at 500oC for various time periods to impart oxide layers of varying thickness. In early 2014, discussions with Indefinite Delivery, Indefinite Quantity (IDIQ) contracted technical consultants from Westinghouse described their previous development (and patents) [R2] on methods of chemical washing to remove some or all of the hydrous oxide layer imparted on UNF cladding during irradiation in light water reactors (LWRs) . Thus, the Oak Ridge National Laboratory (ORNL) study, described herein, was planned to extend the KAERI study on the effects of anhydrous oxide layers, but on larger ~100-gram samples of unirradiated zirconium alloy cladding tubes, and to investigate the effects of various methods of chemical pretreatment prior to chlorination with 100% chlorine on the average reaction rates and Cl2 usage efficiencies.« less

The effect of lignin removal by alkaline peroxide pretreatment on the susceptibility of corn stover to purified cellulolytic and xylanolytic enzymes.

PubMed

Selig, Michael J; Vinzant, Todd B; Himmel, Michael E; Decker, Stephen R

2009-05-01

Pretreatment of corn stover with alkaline peroxide (AP) at pH 11.5 resulted in reduction of lignin content in the residual solids as a function of increasing batch temperature. Scanning electron microscopy of these materials revealed notably more textured surfaces on the plant cell walls as a result of the delignifying pretreatment. As expected, digestion of the delignified samples with commercial cellulase preparations showed an inverse relationship between the content of lignin present in the residual solids after pretreatment and the extent of both glucan and xylan conversion achievable. Digestions with purified enzymes revealed that decreased lignin content in the pretreated solids did not significantly impact the extent of glucan conversion achievable by cellulases alone. Not until purified xylanolytic activities were included with the cellulases were significant improvements in glucan conversion realized. In addition, an inverse relationship was observed between lignin content after pretreatment and the extent of xylan conversion achievable in a 24-h period with the xylanolytic enzymes in the absence of the cellulases. This observation, coupled with the direct relationship between enzymatic xylan and glucan conversion observed in a number of cases, suggests that the presence of lignins may not directly occlude cellulose present in lignocelluloses but rather impact cellulase action indirectly by its association with xylan.

Low severity coal liquefaction promoted by cyclic olefins. Quarterly report, January--March 1994

DOE Office of Scientific and Technical Information (OSTI.GOV)

Curtis, C.W.

Previous research has suggested that using a more effective hydrogen donor solvent in the low severity coal liquefaction reaction improves coal conversion. In order to understand the results of these methods, both independently and combined, a factorial experiment was designed. Pretreating coal with hydrochloric and sulfurous acid solutions in both water and methanol is compared with pretreating coal using only methanol and with no pretreatment. The effects of these pretreatments on coal liquefaction behavior are contrasted with the ammonium acetate pretreatment. Within each of these, individual reactions are performed with the hydroaromatic 1,2,3,4-tetrahydronaphthalene (tetralin, TET) and the cyclic olefin 1,4,5,8-tetrahydronaphthalenemore » (isotetralin, ISO). The final aspect of the factorial experiment is the comparison of Wyodak subbituminous coal (WY) from the Argonne Premium Sample Bank and Black Thunder subbituminous coal (BT) provided by Amoco. Half of the reactions in the matrix have now been completed. In all but one case, Black Thunder-HCl/H{sub 2}O, the ISO proved to be more reactive than TET. After the other four reactions using this combination are complete, the average conversion may be greater with the cyclic olefin. The second part of this paper describes the current and future work with Fourier transform infrared spectroscopy. The objective of this work is to determine the kinetics of reaction of isotetralin at high temperatures and pressures. This quarter combinations of three products typically produced from isotetralin were used in spectral subtraction.« less

Improvement of enzymatic hydrolysis and ethanol production from corn stalk by alkali and N-methylmorpholine-N-oxide pretreatments.

PubMed

Cai, Ling-Yan; Ma, Yu-Long; Ma, Xiao-Xia; Lv, Jun-Min

2016-07-01

A combinative technology of alkali and N-methylmorpholine-N-oxide (NMMO) was used to pretreat corn stalk (CS) for improving the efficiencies of subsequent enzymatic hydrolysis and ethanol fermentation. The results showed that this strategy could not only remove hemicellulose and lignin but also decrease the crystallinity of cellulose. About 98.0% of enzymatic hydrolysis yield was obtained from the pretreated CS as compared with 46.9% from the untreated sample. The yield for corresponding ethanol yield was 64.6% while untreated CS was only 18.8%. Besides, xylose yield obtained from the untreated CS was only 11.1%, while this value was 93.8% for alkali with NMMO pretreated sample. These results suggest that a combination of alkali with 50% (wt/wt) NMMO solution may be a promising alternative for pretreatment of lignocellulose, which can increase the productions of subsequent enzymatic hydrolysis and ethanol fermentation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Understanding changes in cellulose crystalline structure of lignocellulosic biomass during ionic liquid pretreatment by XRD.

PubMed

Zhang, Jiafu; Wang, Yixun; Zhang, Liye; Zhang, Ruihong; Liu, Guangqing; Cheng, Gang

2014-01-01

X-ray diffraction (XRD) was used to understand the interactions of cellulose in lignocellulosic biomass with ionic liquids (ILs). The experiment was designed in such a way that the process of swelling and solubilization of crystalline cellulose in plant cell walls was followed by XRD. Three different feedstocks, switchgrass, corn stover and rice husk, were pretreated using 1-butyl-3-methylimidazolium acetate ([C4mim][OAc]) at temperatures of 50-130°C for 6h. At a 5 wt.% biomass loading, increasing pretreatment temperature led to a drop in biomass crystallinity index (CrI), which was due to swelling of crystalline cellulose. After most of the crystalline cellulose was swollen with IL molecules, a low-order structure was found in the pretreated samples. Upon further increasing temperature, cellulose II structure started to form in the pretreated biomass samples as a result of solubilization of cellulose in [C4mim][OAc] and subsequent regeneration. Copyright © 2013 Elsevier Ltd. All rights reserved.

Optimization of enzymatic hydrolysis for ethanol production by simultaneous saccharification and fermentation of wastepaper.

PubMed

Sangkharak, Kanokphorn

2011-11-01

The present study investigated the development of high sugar production by optimization of an enzymatic hydrolysis process using both conventional and statistical methods, as well as the production of ethanol by the selected wastepaper source. Among four sources of pretreated wastepaper including office paper, newspaper, handbills and cardboard, office paper gave the highest values of cellulose (87.12%) and holocelluloses (89.07%). The effects of the amount of wastepaper, the pretreatment method and the type of enzyme on reducing sugar production from office paper were studied using conventional methods. The highest reducing sugar production (1851.28 µg L(-1); 37.03% conversion of glucose) was obtained from the optimal condition containing 40 mg of office paper, pretreated with stream explosion and hydrolysed with the combination of cellulase from Aspergillus niger and Trichoderma viride at the fixed loading rate of 20 FPU g(-1) sample. The effects of interaction of wastepaper amount and enzyme concentration as well as incubation time were studied by a statistical method using central composite design. The optimal medium composition consisted of 43.97 µg L(-1), 28.14 FPU g(-1) sample and 53.73 h of wastepaper, enzyme concentration and incubation time, respectively, and gave the highest amount of sugar production (2184.22 µg L(-1)) and percentage conversion of glucose (43.68%). The ethanol production from pretreated office paper using Saccharomyces cerevisiae in a simultaneous saccharification and fermentation process was 21.02 g L(-1) after 36 h of cultivation, corresponding to an ethanol volumetric production rate of 0.58 g ethanol L(-1) h(-1).

Bonding effectiveness to different chemically pre-treated dental zirconia.

PubMed

Inokoshi, Masanao; Poitevin, André; De Munck, Jan; Minakuchi, Shunsuke; Van Meerbeek, Bart

2014-09-01

The objective of this study was to evaluate the effect of different chemical pre-treatments on the bond durability to dental zirconia. Fully sintered IPS e.max ZirCAD (Ivoclar Vivadent) blocks were subjected to tribochemical silica sandblasting (CoJet, 3M ESPE). The zirconia samples were additionally pre-treated using one of four zirconia primers/adhesives (Clearfil Ceramic Primer, Kuraray Noritake; Monobond Plus, Ivoclar Vivadent; Scotchbond Universal, 3M ESPE; Z-PRIME Plus, Bisco). Finally, two identically pre-treated zirconia blocks were bonded together using composite cement (RelyX Ultimate, 3M ESPE). The specimens were trimmed at the interface to a cylindrical hourglass and stored in distilled water (7 days, 37 °C), after which they were randomly tested as is or subjected to mechanical ageing involving cyclic tensile stress (10 N, 10 Hz, 10,000 cycles). Subsequently, the micro-tensile bond strength was determined, and SEM fractographic analysis performed. Weibull analysis revealed the highest Weibull scale and shape parameters for the 'Clearfil Ceramic Primer/mechanical ageing' combination. Chemical pre-treatment of CoJet (3M ESPE) sandblasted zirconia using Clearfil Ceramic Primer (Kuraray Noritake) and Monobond Plus (Ivoclar Vivadent) revealed a significantly higher bond strength than when Scotchbond Universal (3M ESPE) and Z-PRIME Plus (Bisco) were used. After ageing, Clearfil Ceramic Primer (Kuraray Noritake) revealed the most stable bond durability. Combined mechanical/chemical pre-treatment, the latter with either Clearfil Ceramic Primer (Kuraray Noritake) or Monobond Plus (Ivoclar Vivadent), resulted in the most durable bond to zirconia. As a standard procedure to durably bond zirconia to tooth tissue, the application of a combined 10-methacryloyloxydecyl dihydrogen phosphate/silane ceramic primer to zirconia is clinically highly recommended.

Predictors of Treatment Effectiveness for Youth with ASD and Comorbid Anxiety Disorders: It All Depends on the Family?

ERIC Educational Resources Information Center

van Steensel, F. J.; Zegers, V. M.; Bögels, S. M.

2017-01-01

The study aimed to explore predictors of treatment effectiveness in a sample of 79 children with ASD who received cognitive behavioral therapy (CBT) for their anxiety disorders. Severity of anxiety disorders and anxiety symptoms were used to measure treatment effectiveness and was assessed pre-treatment, post-treatment, 3 months-, 1 and 2 years…

Interface actions between TiO2 and porous diatomite on the structure and photocatalytic activity of TiO2-diatomite

NASA Astrophysics Data System (ADS)

Xia, Yue; Li, Fangfei; Jiang, Yinshan; Xia, Maosheng; Xue, Bing; Li, Yanjuan

2014-06-01

TiO2-diatomite photocatalysts were prepared by sol-gel process with various pre-modified diatomite. In order to obtain diatomite with different surface characteristics, two modification approaches including calcination and phosphoric acid treatment on the micro-structure of diatomite are introduced. The photocatalysts were characterized by XRD, XPS, nitrogen adsorption-desorption isotherms and micromorphology analysis. The results indicate that, compared with pure TiO2, the anatase-to-rutile phase transition temperature of TiO2 loaded on diatomite carrier is significantly increased to nearly 900 °C, depending on the different pretreatment method of diatomite. The photocatalytic activities of different samples were evaluated by their degradation rate of methyl orange (MO) dye under UV and visible-light irradiation. The samples prepared by phosphoric acid pretreatment method exhibit the highest photocatalytic activity. After 90 min of UV irradiation, about 90% of MO is decomposed by the best effective photocatalyst. And after 8 h visible-light irradiation, nearly 60% of MO is decomposed by the same sample. Further mechanism investigation reveals that the H3PO4 pretreatment process can obviously change the surface features of diatomite carrier, cause the formation of Si-O-Ti bond, increase the binding strength between TiO2 and diatomite, restrain crystal growth of loaded TiO2, and thus form thermal-stable mesoporous structure at the granular spaces. It helps to build micro-, meso- and macro-porous hierarchical porous structure in TiO2-diatomite, and improves the charge and mass transfer efficiency during catalyzing process, resulting in the significantly increased photocatalytic activity of TiO2-diatomite pretreated by phosphoric acid.

Quality of life and communication in orthognathic treatment.

PubMed

Catt, Susan L; Ahmad, Sofia; Collyer, Jeremy; Hardwick, Lauren; Shah, Nahush; Winchester, Lindsay

2018-06-01

The primary aim was to determine what, if any, relationships exist between communication and quality of life in patients receiving orthognathic treatment since this has not been explored. A secondary aim was to compare the Quality of Life (QoL) of a pre-treatment sample with those at 2 years post-surgery. A cross-sectional questionnaire method was used. Outpatient clinics providing orthognathic treatment at four UK hospital sites. Two separate samples of pre-treatment (n = 73) and 2-year post-surgery (n = 78) patients participated in the study. At clinic appointments, all eligible patients were invited to complete the Orthognathic Quality of Life Questionnaire (OQLQ), a previously validated condition-specific quality of life measure. At the same time, participants at the 2-year post-surgery stage also completed a second short questionnaire, the Communication Assessment Tool-Team (CAT-T), where they rated the quality of communication they had received during treatment. One hundred and fifty-one complete responses were received. The average age was 24.5 years (S.D. 9.77) and the majority (67%) were female in both groups. Statistically significant associations were found between QoL and quality of communication in the treated sample. Findings also showed a comparatively poorer QoL for the pre-treatment participants. This reduced QoL was more pronounced in females than males for all aspects except dentofacial appearance. There was an improvement in QoL for patients at 2 years post-surgery compared to pre-treatment. There is an association between QoL and quality of communication as reported by participants at 2 years post-surgery. These novel findings are similar to outcomes in other patient settings such as oncology, but further investigation is required to establish the direction of cause and effect.

Pretreatment of different biological matrices for exogenous testosterone analysis: a review.

PubMed

Pizzato, Edna Carolina; Filonzi, Marcelo; Rosa, Hemerson Silva da; de Bairros, André Valle

2017-11-01

The presence of exogenous testosterone has been monitored mainly in the urine and blood. However, other biological matrices such as hair, nail, and saliva samples can be used successfully for in vivo measurement. Chromatographic analysis requires pretreatment to obtain free testosterone and its metabolites. Among the pretreatment procedures, digestion, hydrolysis and solvolysis steps are conducted to reach the analytical purpose. Digestion assay is indicated for hair and nail samples. First, it is recommended to perform the decontamination step. After that, alkaline solution (NaOH), organic solvents and other reagents can be added to the samples and incubated under determined conditions for the digestion step. Hydrolysis assay is recommended to urine and blood samples. Acid hydrolysis cleaves conjugated testosterone and its metabolites using HCl or H 2 SO 4 solution at appropriate time and temperature. However, there is formation of interferent compounds, degradation of dehydroepiandrosterone and decrease of peak resolution for epitestosterone. Enzymatic hydrolysis is an alternative technique able to promote free testosterone and its metabolites with low degradation. It is important to establish the best conditions according to the biological fluid and the amount of the sample. Sulfatase enzyme is recommended together with β-glucuronidase to cleave sulfoconjugate steroids. Solvolysis assay is similar to acid hydrolysis, but organic solvents are responsible to promote steroid deconjugation. Other approaches such as combination of different pretreatments, surface response or ultrasonic energy have been used to obtain the total of free steroids. So, the biological matrix defines the best procedure for pretreatment to achieve the analytical purpose, knowing its advantages and limitations.

Role of modifier in microwave assisted extraction of oleanolic acid from Gymnema sylvestre: application of green extraction technology for botanicals.

PubMed

Mandal, Vivekananda; Dewanjee, Saikat; Mandal, Subhash C

2009-08-01

This work highlights the development of a green extraction technology for botanicals with the use of microwave energy. Taking into consideration the extensive time involved in conventional extraction methods, coupled with usage of large volumes of organic solvent and energy resources, an ecofriendly green method that can overcome the above problems has been developed. The work compares the effect of sample pretreatment with untreated sample for improved yield of oleanolic acid from Gymnema sylvestre leaves. The pretreated sample with water produced 0.71% w/w oleanolic acid in one extraction cycle with 500 W microwave power, 25 mL methanol and only an 8 min extraction time. On the other hand, a conventional heat reflux extraction for 6 hours could produce only 0.62% w/w oleanolic acid. The detailed mechanism of extraction has been studied through scanning electron micrographs. The environmental impact of the proposed green method has also been evaluated.

Rapid screening of aflatoxin B1 in beer by fluorescence polarization immunoassay.

PubMed

Beloglazova, N V; Eremin, S A

2015-09-01

This manuscript describes the development of a sensitive, fast and easily-performed fluorescence polarization immunoassay (FPIA) for the mycotoxin aflatoxin B1 (AFB1) in various beer samples, both lager and dark. The highest sensitivity was determined for six poly- and monoclonal antibodies selective towards aflatoxins. The sample pretreatment design was emphasized since beer samples are characterized by extremely diverse matrices. Herein, the choice of sorbent for effective removal of matrix interferences prior to analysis was crucial. The samples were diluted with a borate buffer solution containing 1% PEG 6000 and passed through the clean-up column packed with NH2-derivated silica. This sample pretreatment technique was perfectly suitable for the FPIA of lager beer samples, but for dark beer and ale it did not suffice. An artificial matrix was constructed to plot a calibration curve and quantify the results of the latter samples. The developed immunoassay was characterized by a limit of detection of 1 ng mL(-1). Apparent recovery values of 89-114% for lager and 80-125% for dark beer were established. The FPIA data for AFB1 was characterized by elevated linear regression coefficients, 0.9953 for spiked lager and 0.9895 for dark beer samples respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

Cellulase digestibility of pretreated biomass is limited by cellulose accessibility.

PubMed

Jeoh, Tina; Ishizawa, Claudia I; Davis, Mark F; Himmel, Michael E; Adney, William S; Johnson, David K

2007-09-01

Attempts to correlate the physical and chemical properties of biomass to its susceptibility to enzyme digestion are often inconclusive or contradictory depending on variables such as the type of substrate, the pretreatment conditions and measurement techniques. In this study, we present a direct method for measuring the key factors governing cellulose digestibility in a biomass sample by directly probing cellulase binding and activity using a purified cellobiohydrolase (Cel7A) from Trichoderma reesei. Fluorescence-labeled T. reesei Cel7A was used to assay pretreated corn stover samples and pure cellulosic substrates to identify barriers to accessibility by this important component of cellulase preparations. The results showed cellulose conversion improved when T. reesei Cel7A bound in higher concentrations, indicating that the enzyme had greater access to the substrate. Factors such as the pretreatment severity, drying after pretreatment, and cellulose crystallinity were found to directly impact enzyme accessibility. This study provides direct evidence to support the notion that the best pretreatment schemes for rendering biomass more digestible to cellobiohydrolase enzymes are those that improve access to the cellulose in biomass cell walls, as well as those able to reduce the crystallinity of cell wall cellulose.

Frontiers of Two-Dimensional Correlation Spectroscopy. Part 1. New concepts and noteworthy developments

NASA Astrophysics Data System (ADS)

Noda, Isao

2014-07-01

A comprehensive survey review of new and noteworthy developments, which are advancing forward the frontiers in the field of 2D correlation spectroscopy during the last four years, is compiled. This review covers books, proceedings, and review articles published on 2D correlation spectroscopy, a number of significant conceptual developments in the field, data pretreatment methods and other pertinent topics, as well as patent and publication trends and citation activities. Developments discussed include projection 2D correlation analysis, concatenated 2D correlation, and correlation under multiple perturbation effects, as well as orthogonal sample design, predicting 2D correlation spectra, manipulating and comparing 2D spectra, correlation strategy based on segmented data blocks, such as moving-window analysis, features like determination of sequential order and enhanced spectral resolution, statistical 2D spectroscopy using covariance and other statistical metrics, hetero-correlation analysis, and sample-sample correlation technique. Data pretreatment operations prior to 2D correlation analysis are discussed, including the correction for physical effects, background and baseline subtraction, selection of reference spectrum, normalization and scaling of data, derivatives spectra and deconvolution technique, and smoothing and noise reduction. Other pertinent topics include chemometrics and statistical considerations, peak position shift phenomena, variable sampling increments, computation and software, display schemes, such as color coded format, slice and power spectra, tabulation, and other schemes.

Removal of oil palm trunk lignin in ammonium hydroxide pretreatment

NASA Astrophysics Data System (ADS)

Az-Zahraa, Balqis; Zakaria, Sarani; Daud, Muhammad F. B.; Jaafar, Sharifah Nabihah Syed

2018-04-01

Alkaline pretreatment using ammonium hydroxide, NH4OH serves as one of a process to remove lignin from lignocellulosic biomass such as oil palm trunk fiber. In this study, the effect of NH4OH pretreatment on removal of oil palm trunk lignin was investigated. The oil palm trunk fiber was dissolved in NH4OH with different concentrations (6, 8 and 10 %), different duration (3, 5 and 7 h) and temperatures (60, 80 and 100 °C). The samples were analyzed by using UV-Vis to estimate the concentration of extracted lignin. The result indicates that the optimum conditions to gain maximum extracted lignin were 8% NH4OH, 100 °C and 5 h with concentration of 64 mgL-1 while the lowest was at 6% NH4OH, 100 °C and 5 h with concentration of 62.5 mgL-1.

Simultaneous enzymatic hydrolysis and anaerobic biodegradation of lipid-rich wastewater from poultry industry

NASA Astrophysics Data System (ADS)

Dors, Gisanara; Mendes, Adriano A.; Pereira, Ernandes B.; de Castro, Heizir F.; Furigo, Agenor

2013-03-01

Simultaneous enzymatic hydrolysis and anaerobic biodegradation of lipid-rich wastewater from poultry industry with porcine pancreatic lipase at different concentrations (from 1.0 to 3.0 g L-1) were performed. The efficiency of the enzymatic pretreatment was measured by the Chemical Oxygen Demand (COD) removal and formation of methane. All samples pretreated with lipase showed a positive effect on the COD removal and formation of methane. After 30 days of anaerobic biodegradation the methane production varied from 569 ± 95 to 1,101 ± 10 mL for crude wastewater and pretreated at 3.0 g L-1 enzyme, respectively. COD removal of wastewater supplemented at different enzyme concentrations was found to be threefold higher than crude wastewater. The use of lipases seems to be a promising alternative for treating lipid-rich wastewaters such as those from the poultry industry.

Production of high concentrated cellulosic ethanol by acetone/water oxidized pretreated beech wood.

PubMed

Katsimpouras, Constantinos; Kalogiannis, Konstantinos G; Kalogianni, Aggeliki; Lappas, Angelos A; Topakas, Evangelos

2017-01-01

Lignocellulosic biomass is an abundant and inexpensive resource for biofuel production. Alongside its biotechnological conversion, pretreatment is essential to enable efficient enzymatic hydrolysis by making cellulose susceptible to cellulases. Wet oxidation of biomass, such as acetone/water oxidation, that employs hot acetone, water, and oxygen, has been found to be an attractive pretreatment method for removing lignin while producing less degradation products. The remaining enriched cellulose fraction has the potential to be utilized under high gravity enzymatic saccharification and fermentation processes for the cost-competing production of bioethanol. Beech wood residual biomass was pretreated following an acetone/water oxidation process aiming at the production of high concentration of cellulosic ethanol. The effect of pressure, reaction time, temperature, and acetone-to-water ratio on the final composition of the pretreated samples was studied for the efficient utilization of the lignocellulosic feedstock. The optimal conditions were acetone/water ratio 1:1, 40 atm initial pressure of 40 vol% O 2 gas, and 64 atm at reaction temperature of 175 °C for 2 h incubation. The pretreated beech wood underwent an optimization step studying the effect of enzyme loading and solids content on the enzymatic liquefaction/saccharification prior to fermentation. In a custom designed free-fall mixer at 50 °C for either 6 or 12 h of prehydrolysis using an enzyme loading of 9 mg/g dry matter at 20 wt% initial solids content, high ethanol concentration of 75.9 g/L was obtained. The optimization of the pretreatment process allowed the efficient utilization of beech wood residual biomass for the production of high concentrations of cellulosic ethanol, while obtaining lignin that can be upgraded towards high-added-value chemicals. The threshold of 4 wt% ethanol concentration that is required for the sustainable bioethanol production was surpassed almost twofold, underpinning the efficient conversion of biomass to ethanol and bio-based chemicals on behalf of the biorefinery concept.

Dry olive leaf extract counteracts L-thyroxine-induced genotoxicity in human peripheral blood leukocytes in vitro.

PubMed

Topalović, Dijana Žukovec; Živković, Lada; Čabarkapa, Andrea; Djelić, Ninoslav; Bajić, Vladan; Dekanski, Dragana; Spremo-Potparević, Biljana

2015-01-01

The thyroid hormones change the rate of basal metabolism, modulating the consumption of oxygen and causing production of reactive oxygen species, which leads to the development of oxidative stress and DNA strand breaks. Olive (Olea europaea L.) leaf contains many potentially bioactive compounds, making it one of the most potent natural antioxidants. The objective of this study was to evaluate the genotoxicity of L-thyroxine and to investigate antioxidative and antigenotoxic potential of the standardized oleuropein-rich dry olive leaf extract (DOLE) against hydrogen peroxide and L-thyroxine-induced DNA damage in human peripheral blood leukocytes by using the comet assay. Various concentrations of the extract were tested with both DNA damage inducers, under two different experimental conditions, pretreatment and posttreatment. Results indicate that L-thyroxine exhibited genotoxic effect and that DOLE displayed protective effect against thyroxine-induced genotoxicity. The number of cells with DNA damage, was significantly reduced, in both pretreated and posttreated samples (P < 0.05). Comparing the beneficial effect of all tested concentrations of DOLE, in both experimental protocols, it appears that extract was more effective in reducing DNA damage in the pretreatment, exhibiting protective role against L-thyroxine effect. This feature of DOLE can be explained by its capacity to act as potent free radical scavenger.

Dry Olive Leaf Extract Counteracts L-Thyroxine-Induced Genotoxicity in Human Peripheral Blood Leukocytes In Vitro

PubMed Central

Žukovec Topalović, Dijana; Živković, Lada; Čabarkapa, Andrea; Djelić, Ninoslav; Bajić, Vladan; Spremo-Potparević, Biljana

2015-01-01

The thyroid hormones change the rate of basal metabolism, modulating the consumption of oxygen and causing production of reactive oxygen species, which leads to the development of oxidative stress and DNA strand breaks. Olive (Olea europaea L.) leaf contains many potentially bioactive compounds, making it one of the most potent natural antioxidants. The objective of this study was to evaluate the genotoxicity of L-thyroxine and to investigate antioxidative and antigenotoxic potential of the standardized oleuropein-rich dry olive leaf extract (DOLE) against hydrogen peroxide and L-thyroxine-induced DNA damage in human peripheral blood leukocytes by using the comet assay. Various concentrations of the extract were tested with both DNA damage inducers, under two different experimental conditions, pretreatment and posttreatment. Results indicate that L-thyroxine exhibited genotoxic effect and that DOLE displayed protective effect against thyroxine-induced genotoxicity. The number of cells with DNA damage, was significantly reduced, in both pretreated and posttreated samples (P < 0.05). Comparing the beneficial effect of all tested concentrations of DOLE, in both experimental protocols, it appears that extract was more effective in reducing DNA damage in the pretreatment, exhibiting protective role against L-thyroxine effect. This feature of DOLE can be explained by its capacity to act as potent free radical scavenger. PMID:25789081

Using the properties of soil to speed up the start-up process, enhance process stability, and improve the methane content and yield of solid-state anaerobic digestion of alkaline-pretreated poplar processing residues.

PubMed

Yao, Yiqing; Luo, Yang; Li, Tian; Yang, Yingxue; Sheng, Hongmei; Virgo, Nolan; Xiang, Yun; Song, Yuan; Zhang, Hua; An, Lizhe

2014-01-01

Solid-state anaerobic digestion (SS-AD) was initially adopted for the treatment of municipal solid waste. Recently, SS-AD has been increasingly applied to treat lignocellulosic biomass, such as agricultural and forestry residues. However, studies on the SS-AD process are few. In this study, the process performance and methane yield from SS-AD of alkaline-pretreated poplar processing residues (PPRs) were investigated using the properties of soil, such as buffering capacity and nutritional requirements. The results showed that the lignocellulosic structures of the poplar sample were effectively changed by NaOH pretreatment, as indicated by scanning electron microscopy and Fourier transform infrared spectra analysis. The start-up was markedly hastened, and the process stability was enhanced. After NaOH pretreatment, the maximum methane yield (96.1 L/kg volatile solids (VS)) was obtained under a poplar processing residues-to-soil sample (P-to-S) ratio of 2.5:1, which was 29.9% and 36.1% higher than that of PPRs (74.0 L/kg VS) and that of experiments without NaOH pretreatment (70.6 L/kg VS), respectively. During steady state, the increase in the methane content of the experiment with a P-to-S ratio of 2.5:1 was 4.4 to 50.9% higher than that of the PPRs. Degradation of total solids and volatile solids ranged from 19.3 to 33.0% and from 34.9 to 45.9%, respectively. The maximum reductions of cellulose and hemicellulose were 52.6% and 42.9%, respectively, which were in accordance with the maximal methane yield. T 80 for the maximum methane yield for the experiments with NaOH pretreatment was 11.1% shorter than that for the PPRs. Pretreatment with NaOH and addition of soil led to a significant improvement in the process performance and the methane yield of SS-AD of PPRs. The changes in lignocellulosic structures induced by NaOH pretreatment led to an increase in methane yield. For the purpose of practical applications, SS-AD with soil addition is a convenient, economical, and practical technique.

Testing of Candidate Polymeric Materials for Compatibility with Pure Alternate Pretreat as Part of the Universal Waste Management System (UWMS)

NASA Technical Reports Server (NTRS)

Wingard, C. D.

2018-01-01

The Universal Waste Management System (UWMS) is an improved Waste Collection System for astronauts living and working in low Earth orbit spacecraft. Polymeric materials used in water recovery on International Space Station are regularly exposed to phosphoric acid-treated 'pretreated' urine. Polymeric materials used in UWMS are not only exposed to pretreated urine, but also to concentrated phosphoric acid with oxidizer before dilution known as 'pure pretreat.' Samples of five different polymeric materials immersed in pure pretreat for 1 year were tested for liquid compatibility by measuring changes in storage modulus with a dynamic mechanical analyzer.

Determination of novel brominated flame retardants and polybrominated diphenyl ethers in serum using gas chromatography-mass spectrometry with two simplified sample preparation procedures.

PubMed

Gao, Le; Li, Jian; Wu, Yandan; Yu, Miaohao; Chen, Tian; Shi, Zhixiong; Zhou, Xianqing; Sun, Zhiwei

2016-11-01

Two simple and efficient pretreatment procedures have been developed for the simultaneous extraction and cleanup of six novel brominated flame retardants (NBFRs) and eight common polybrominated diphenyl ethers (PBDEs) in human serum. The first sample pretreatment procedure was a quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based approach. An acetone/hexane mixture was employed to isolate the lipid and analytes from the serum with a combination of MgSO 4 and NaCl, followed by a dispersive solid-phase extraction (d-SPE) step using C18 particles as a sorbent. The second sample pretreatment procedure was based on solid-phase extraction. The sample extraction and cleanup were conducted directly on an Oasis HLB SPE column using 5 % aqueous isopropanol, concentrated sulfuric acid, and 10 % aqueous methanol, followed by elution with dichloromethane. The NBFRs and PBDEs were then detected using gas chromatography-negative chemical ionization mass spectrometry (GC-NCI MS). The methods were assessed for repeatability, accuracy, selectivity, limits of detection (LODs), and linearity. The results of spike recovery experiments in fetal bovine serum showed that average recoveries ranged from 77.9 % to 128.8 % with relative standard deviations (RSDs) from 0.73 % to 12.37 % for most of the analytes. The LODs for the analytes in fetal bovine serum ranged from 0.3 to 50.8 pg/mL except for decabromodiphenyl ethane. The proposed method was successfully applied to the determination of the 14 brominated flame retardants in human serum. The two pretreatment procedures described here are simple, accurate, and precise, and are suitable for the routine analysis of human serum. Graphical Abstract Workflow of a QuEChERS-based approach (top) and an SPE-based approach (bottom) for the detection of PBDEs and NBFRs in serum.

Levosimendan: a cardiovascular drug to prevent liver ischemia-reperfusion injury?

PubMed

Onody, Peter; Stangl, Rita; Fulop, Andras; Rosero, Oliver; Garbaisz, David; Turoczi, Zsolt; Lotz, Gabor; Rakonczay, Zoltan; Balla, Zsolt; Hegedus, Viktor; Harsanyi, Laszlo; Szijarto, Attila

2013-01-01

Temporary occlusion of the hepatoduodenal ligament leads to an ischemic-reperfusion (IR) injury in the liver. Levosimendan is a new positive inotropic drug, which induces preconditioning-like adaptive mechanisms due to opening of mitochondrial KATP channels. The aim of this study was to examine possible protective effects of levosimendan in a rat model of hepatic IR injury. Levosimendan was administered to male Wistar rats 1 hour (early pretreatment) or 24 hours (late pretreatment) before induction of 60-minute segmental liver ischemia. Microcirculation of the liver was monitored by laser Doppler flowmeter. After 24 hours of reperfusion, liver and blood samples were taken for histology, immuno- and enzyme-histochemistry (TUNEL; PARP; NADH-TR) as well as for laboratory tests. Furthermore, liver antioxidant status was assessed and HSP72 expression was measured. In both groups pretreated with levosimendan, significantly better hepatic microcirculation was observed compared to respective IR control groups. Similarly, histological damage was also reduced after levosimendan administration. This observation was supported by significantly lower activities of serum ALT (p early = 0.02; p late = 0.005), AST (p early = 0.02; p late = 0.004) and less DNA damage by TUNEL test (p early = 0.05; p late = 0.034) and PAR positivity (p early = 0.02; p late = 0.04). Levosimendan pretreatment resulted in significant improvement of liver redox homeostasis. Further, significantly better mitochondrial function was detected in animals receiving late pretreatment. Finally, HSP72 expression was increased by IR injury, but it was not affected by levosimendan pretreatment. Levosimendan pretreatment can be hepatoprotective and it could be useful before extensive liver resection.

Microwave assisted alkaline pretreatment to enhance enzymatic saccharification of catalpa sawdust.

PubMed

Jin, Shuguang; Zhang, Guangming; Zhang, Panyue; Li, Fan; Wang, Siqi; Fan, Shiyang; Zhou, Shuqiong

2016-12-01

Catalpa sawdust, a promising biofuel production biomass, was pretreated by microwave-water, -NaOH, and -Ca(OH) 2 to enhance enzymatic digestibility. After 48h enzymatic hydrolysis, microwave-Ca(OH) 2 pretreated sample showed the highest reducing sugar yield. The content of hemicellulose and lignin in catalpa sawdust decreased after microwave-alkali pretreatment. SEM observation showed that the catalpa sawdust surface with microwave-Ca(OH) 2 pretreatment suffered the most serious erosion. Crystallinity index of catalpa sawdust increased after all three kinds of pretreatment. The optimum conditions of microwave-Ca(OH) 2 pretreatment were particle size of 40mesh, Ca(OH) 2 dosage of 2.25% (w/v), microwave power of 400W, pretreatment time of 6min, enzyme loading of 175FPU/g, and hydrolysis time of 96h, and the reducing sugar yield of microwave-Ca(OH) 2 pretreated catalpa sawdust reached 402.73mg/g, which increased by 682.15% compared with that of raw catalpa sawdust. The catalpa sawdust with microwave-Ca(OH) 2 pretreatment is promising for biofuel production with great potential. Copyright © 2016 Elsevier Ltd. All rights reserved.

Physiological and behavioral indices of emotion dysregulation as predictors of outcome from cognitive behavioral therapy and acceptance and commitment therapy for anxiety.

PubMed

Davies, Carolyn D; Niles, Andrea N; Pittig, Andre; Arch, Joanna J; Craske, Michelle G

2015-03-01

Identifying for whom and under what conditions a treatment is most effective is an essential step toward personalized medicine. The current study examined pre-treatment physiological and behavioral variables as predictors and moderators of outcome in a randomized clinical trial comparing cognitive behavioral therapy (CBT) and acceptance and commitment therapy (ACT) for anxiety disorders. Sixty individuals with a DSM-IV defined principal anxiety disorder completed 12 sessions of either CBT or ACT. Baseline physiological and behavioral variables were measured prior to entering treatment. Self-reported anxiety symptoms were assessed at pre-treatment, post-treatment, and 6- and 12-month follow-up from baseline. Higher pre-treatment heart rate variability was associated with worse outcome across ACT and CBT. ACT outperformed CBT for individuals with high behavioral avoidance. Subjective anxiety levels during laboratory tasks did not predict or moderate treatment outcome. Due to small sample sizes of each disorder, disorder-specific predictors were not tested. Future research should examine these predictors in larger samples and across other outcome variables. Lower heart rate variability was identified as a prognostic indicator of overall outcome, whereas high behavioral avoidance was identified as a prescriptive indicator of superior outcome from ACT versus CBT. Investigation of pre-treatment physiological and behavioral variables as predictors and moderators of outcome may help guide future treatment-matching efforts. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of lime and hydrothermal pretreatments for efficient enzymatic hydrolysis of raw sugarcane bagasse.

PubMed

Grimaldi, Maira Prearo; Marques, Marina Paganini; Laluce, Cecília; Cilli, Eduardo Maffud; Sponchiado, Sandra Regina Pombeiro

2015-01-01

Ethanol production from sugarcane bagasse requires a pretreatment step to disrupt the cellulose-hemicellulose-lignin complex and to increase biomass digestibility, thus allowing the obtaining of high yields of fermentable sugars for the subsequent fermentation. Hydrothermal and lime pretreatments have emerged as effective methods in preparing the lignocellulosic biomass for bioconversion. These pretreatments are advantageous because they can be performed under mild temperature and pressure conditions, resulting in less sugar degradation compared with other pretreatments, and also are cost-effective and environmentally sustainable. In this study, we evaluated the effect of these pretreatments on the efficiency of enzymatic hydrolysis of raw sugarcane bagasse obtained directly from mill without prior screening. In addition, we evaluated the structure and composition modifications of this bagasse after lime and hydrothermal pretreatments. The highest cellulose hydrolysis rate (70 % digestion) was obtained for raw sugarcane bagasse pretreated with lime [0.1 g Ca(OH)2/g raw] for 60 min at 120 °C compared with hydrothermally pretreated bagasse (21 % digestion) under the same time and temperature conditions. Chemical composition analyses showed that the lime pretreatment of bagasse promoted high solubilization of lignin (30 %) and hemicellulose (5 %) accompanied by a cellulose accumulation (11 %). Analysis of pretreated bagasse structure revealed that lime pretreatment caused considerable damage to the bagasse fibers, including rupture of the cell wall, exposing the cellulose-rich areas to enzymatic action. We showed that lime pretreatment is effective in improving enzymatic digestibility of raw sugarcane bagasse, even at low lime loading and over a short pretreatment period. It was also demonstrated that this pretreatment caused alterations in the structure and composition of raw bagasse, which had a pronounced effect on the enzymes accessibility to the substrate, resulting in an increase of cellulose hydrolysis rate. These results indicate that the use of raw sugarcane bagasse (without prior screening) pretreated with lime (cheaper and environmentally friendly reagent) may represent a cost reduction in the cellulosic ethanol production.

Effect of osmotic dehydration and vacuum-frying parameters to produce high-quality mango chips.

PubMed

Nunes, Yolanda; Moreira, Rosana G

2009-09-01

Mango (Mangifera indica L.) is a fruit rich in flavor and nutritional values, which is an excellent candidate for producing chips. The objective of this study was to develop high-quality mango chips using vacuum frying. Mango ("Tommy Atkins") slices were pretreated with different maltodextrin concentrations (40, 50, and 65, w/v), osmotic dehydration times (45, 60, and 70 min), and solution temperatures (22 and 40 degrees C). Pretreated slices were vacuum fried at 120, 130, and 138 degrees C and product quality attributes (oil content, texture, color, carotenoid content) determined. The effect of frying temperatures at optimum osmotic dehydration times (65 [w/v] at 40 degrees C) was assessed. All samples were acceptable (scores > 5) to consumer panelists. The best mango chips were those pretreated with 65 (w/v) concentration for 60 min and vacuum fried at 120 degrees C. Mango chips under atmospheric frying had less carotenoid retention (32%) than those under vacuum frying (up to 65%). These results may help further optimize vacuum-frying processing of high-quality fruit-based snacks.

SPRUCE Pretreatment Plant Tissue Analyses, 2009 through 2013

DOE Data Explorer

Phillips, J. R. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A; Brice, D. J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A; Hanson, P. J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A; Childs, J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A; Iversen, C. M. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A; Norby, R. J. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A; Warren, J. M. [Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tennessee, U.S.A

2009-12-01

This data set reports the results of elemental analyses of foliar and stem/woody twig plant tissues collected at the SPRUCE site in 2009, 2012, and 2013. Samples were obtained at various locations around the S1 Bog and from within the developing experimental treatment plots. These are pretreatment vegetation samples, collected prior to initiation of the SPRUCE experiment heating and elevated CO2 treatments.

Comparison of pretreatment methods on the enzymatic Saccharification of aspen wood

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pinto, J.H.; Kamden, D.P.

Five different chemical pretreatments, using dilute sulfuric acid, sodium hydroxide, hydrogen peroxide and sodium hydroxide, peroxy-monosulfate, and acetic acid, were applied to aspen thermomechanical fibers. The pretreated fibers were submitted to enzymatic hydrolysis and the liberated glucose was monitored. High glucose concentrations were observed for the peroxymonosulfate and the acetic acid pretreated samples. Glucose concentrations greater than 25 g/L were obtained in these cases. This corresponds to conversions on the order of 90% of the retreated substrate glucose content. 18 refs., 1 fig., 4 tabs.

Determination of lysine content based on an in situ pretreatment and headspace gas chromatographic measurement technique.

PubMed

Wan, Xiao-Fang; Liu, Bao-Lian; Yu, Teng; Yan, Ning; Chai, Xin-Sheng; Li, You-Ming; Chen, Guang-Xue

2018-05-01

This work reports on a simple method for the determination of lysine content by an in situ sample pretreatment and headspace gas chromatographic measurement (HS-GC) technique, based on carbon dioxide (CO 2 ) formation from the pretreatment reaction (between lysine and ninhydrin solution) in a closed vial. It was observed that complete lysine conversion to CO 2 could be achieved within 60 min at 60 °C in a phosphate buffer medium (pH = 4.0), with a minimum molar ratio of ninhydrin/lysine of 16. The results showed that the method had a good precision (RSD < 5.23%) and accuracy (within 6.80%), compared to the results measured by a reference method (ninhydrin spectroscopic method). Due to the feature of in situ sample pretreatment and headspace measurement, the present method becomes very simple and particularly suitable to be used for batch sample analysis in lysine-related research and applications. Graphical abstract The flow path of the reaction and HS-GC measurement for the lysine analysis.

Initial response of soil carbon and nitrogen to harvest intensity and competing vegetation control in douglas-fir (Pseudotsuga menziesii) plantations of the Pacific Northwest

Treesearch

Robert A. Slesak; Stephen H. Schoenholtz; Timothy B. Harrington; Nathan A. Meehan

2011-01-01

We assessed the effect of harvest type (bole-only or whole-tree) and vegetation control treatments (initial or annual application of herbicide) on soil C and N at two contrasting sites in the Pacific Northwest. Pretreatment (2003) and posttreatment (2005) soil samples were collected by depth to 60 cm, and a stratified sampling approach based on four surface conditions...

High-performance of Agaricus blazei fungus for the biological pretreatment of elephant grass.

PubMed

Dal Picolli, Thais; Regalin Aver, Kaliane; Claudete Fontana, Roselei; Camassola, Marli

2018-01-01

Biological pre-treatment seems to be promising being an eco-friendly process, with no inhibitor generated during the process. The potential for elephant grass pre-treatment with white degradation fungi Pleurotus ostreatus, Agaricus blazei, Lentinula edodes, Pleurotus citrinopileatus, and Pleurotus djamor, in isolated or mixed cultures of these strains, was evaluated. The highest activities of enzymes involved in the degradation of lignocellulosic biomass (laccases, endoglucanases, xylanases, and β-glucosidases) were observed for A. blazei, L. edodes and the combination of P. ostreatus and A. blazei. In the enzymatic hydrolysis, there was greater release of reducing sugars in the pre-treated elephant grass samples by A. blazei during 10 days (338.91 ± 7.39 mg g -1 of biomass). For this sample, higher lignin reductions, 24.81 and 57.45%, after 15 and 35 days of incubation, respectively, were also verified. These data indicate the potential of macromycetes such as A. blazei to perform biological pre-treatments. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:42-50, 2018. © 2017 American Institute of Chemical Engineers.

Two-step sequential pretreatment for the enhanced enzymatic hydrolysis of coffee spent waste.

PubMed

Ravindran, Rajeev; Jaiswal, Swarna; Abu-Ghannam, Nissreen; Jaiswal, Amit K

2017-09-01

In the present study, eight different pretreatments of varying nature (physical, chemical and physico-chemical) followed by a sequential, combinatorial pretreatment strategy was applied to spent coffee waste to attain maximum sugar yield. Pretreated samples were analysed for total reducing sugar, individual sugars and generation of inhibitory compounds such as furfural and hydroxymethyl furfural (HMF) which can hinder microbial growth and enzyme activity. Native spent coffee waste was high in hemicellulose content. Galactose was found to be the predominant sugar in spent coffee waste. Results showed that sequential pretreatment yielded 350.12mg of reducing sugar/g of substrate, which was 1.7-fold higher than in native spent coffee waste (203.4mg/g of substrate). Furthermore, extensive delignification was achieved using sequential pretreatment strategy. XRD, FTIR, and DSC profiles of the pretreated substrates were studied to analyse the various changes incurred in sequentially pretreated spent coffee waste as opposed to native spent coffee waste. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ammonia Fiber Expansion Pretreatment and Enzymatic Hydrolysis on Two Different Growth Stages of Reed Canarygrass

NASA Astrophysics Data System (ADS)

Bradshaw, Tamika C.; Alizadeh, Hasan; Teymouri, Farzaneh; Balan, Venkatesh; Dale, Bruce E.

Plant materials from the vegetative growth stage of reed canarygrass and the seed stage of reed canarygrass are pretreated by ammonia fiber expansion (AFEX) and enzymatically hydrolyzed using 15 filter paper units (FPU) cellulase/g glucan to evaluate glucose and xylose yields. Percent conversions of glucose and xylose, effects of temperature and ammonia loading, and hydrolysis profiles are analyzed to determine the most effective AFEX treatment condition for each of the selected materials. The controls used in this study were untreated samples of each biomass material. All pretreatment conditions tested enhanced enzyme digestibility and improved sugar conversions for reed canarygrass compared with their untreated counterparts. Based on 168 h hydrolysis results using 15 FPU Spezyme CP cellulase/g glucan the most effective AFEX treatment conditions were determined as: vegetative growth stage of reed canarygrass—100°C, 60% moisture content, 1.2∶1 kg ammonia/kg of dry matter (86% glucose and 78% xylose) and seed stage of reed canarygrass—100°C, 60% moisture content, 0.8∶1 kg ammonia/kg of dry matter (89% glucose and 81% xylose). Supplementation by commercial Multifect 720 xylanase along with cellulase further increased both glucose and xylose yields by 10-12% at the most effective AFEX conditions.

The anti-inflammatory and anti-apoptotic effects of gallic acid against mucosal inflammation- and erosions-induced by gastric ischemia-reperfusion in rats

PubMed Central

Mard, Seyyed Ali; Mojadami, Shahnaz; Farbood, Yaghoob; Gharib Naseri, Mohammad Kazem

2015-01-01

The present study aimed to evaluate the protective effect of gallic acid on gastric mucosal lesions caused by ischemia-reperfusion (I/R) injury in rat. Forty male rats were randomly divided into sham, control (I/R injury) and three gallic acid-pretreated groups. To induce I/R lesions, the celiac artery was clamped for 30 min and then the clamp was removed to allow reperfusion for 6 hr. Pretreated rats received gallic acid (15, 30 or 60 mg kg-1, intraperitoneally) 30 min prior to the induction of I/R injury. Macroscopic and microscopic evaluations of the areas of ulceration were compared. Samples of gastric mucosa were collected to evaluate the protein expression of pro-apoptotic factor, caspase-3, and pro-inflammatory enzyme, inducible nitric oxide synthase (iNOS) using western blot. Pretreatment with gallic acid decreased the total area of gastric lesions. Gallic acid at 30 mg kg-1 decreased the levels of protein expression of caspase-3 and iNOS induced by I/R injury. Our findings showed the protective effect of gallic acid on gastric mucosa against ischemia-reperfusion injury. This effect of gallic acid was mainly mediated by reducing protein expression of iNOS and caspase-3. PMID:26973766

The anti-inflammatory and anti-apoptotic effects of gallic acid against mucosal inflammation- and erosions-induced by gastric ischemia-reperfusion in rats.

PubMed

Mard, Seyyed Ali; Mojadami, Shahnaz; Farbood, Yaghoob; Gharib Naseri, Mohammad Kazem

2015-01-01

The present study aimed to evaluate the protective effect of gallic acid on gastric mucosal lesions caused by ischemia-reperfusion (I/R) injury in rat. Forty male rats were randomly divided into sham, control (I/R injury) and three gallic acid-pretreated groups. To induce I/R lesions, the celiac artery was clamped for 30 min and then the clamp was removed to allow reperfusion for 6 hr. Pretreated rats received gallic acid (15, 30 or 60 mg kg(-1), intraperitoneally) 30 min prior to the induction of I/R injury. Macroscopic and microscopic evaluations of the areas of ulceration were compared. Samples of gastric mucosa were collected to evaluate the protein expression of pro-apoptotic factor, caspase-3, and pro-inflammatory enzyme, inducible nitric oxide synthase (iNOS) using western blot. Pretreatment with gallic acid decreased the total area of gastric lesions. Gallic acid at 30 mg kg(-1) decreased the levels of protein expression of caspase-3 and iNOS induced by I/R injury. Our findings showed the protective effect of gallic acid on gastric mucosa against ischemia-reperfusion injury. This effect of gallic acid was mainly mediated by reducing protein expression of iNOS and caspase-3.

Effect of alkaline microwaving pretreatment on anaerobic digestion and biogas production of swine manure.

PubMed

Yu, Tao; Deng, Yihuan; Liu, Hongyu; Yang, Chunping; Wu, Bingwen; Zeng, Guangming; Lu, Li; Nishimura, Fumitake

2017-05-10

Microwave assisted with alkaline (MW-A) condition was applied in the pretreatment of swine manure, and the effect of the pretreatment on anaerobic treatment and biogas production was evaluated in this study. The two main microwaving (MW) parameters, microwaving power and reaction time, were optimized for the pretreatment. Response surface methodology (RSM) was used to investigate the effect of alkaline microwaving process for manure pretreatment at various values of pH and energy input. Results showed that the manure disintegration degree was maximized of 63.91% at energy input of 54 J/g and pH of 12.0, and variance analysis indicated that pH value played a more important role in the pretreatment than in energy input. Anaerobic digestion results demonstrated that MW-A pretreatment not only significantly increased cumulative biogas production, but also shortened the duration for a stable biogas production rate. Therefore, the alkaline microwaving pretreatment could become an alternative process for effective treatment of swine manure.

Comparison between solid-state and powder-state alkali pretreatment on saccharification and fermentation for bioethanol production from rice straw.

PubMed

Yeasmin, Shabina; Kim, Chul-Hwan; Islam, Shah Md Asraful; Lee, Ji-Young

2016-01-01

The efficacy of different concentrations of NaOH (0.25%, 0.50%, 0.75%, and 1.00%) for the pretreatment of rice straw in solid and powder state in enzymatic saccharification and fermentation for the production of bioethanol was evaluated. A greater amount of biomass was recovered through solid-state pretreatment (3.74 g) from 5 g of rice straw. The highest increase in the volume of rice straw powder as a result of swelling was observed with 1.00% NaOH pretreatment (48.07%), which was statistically identical to 0.75% NaOH pretreatment (32.31%). The surface of rice straw was disrupted by the 0.75% NaOH and 1.00% NaOH pretreated samples as observed using field-emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). In Fourier-transform infrared (FT-IR) spectra, absorbance of hydroxyl groups at 1,050 cm(-1) due to the OH group of lignin was gradually decreased with the increase of NaOH concentration. The greatest amounts of glucose and ethanol were obtained in 1.00% NaOH solid-state pretreated and powder-state hydrolyzed samples (0.804 g g(-1) and 0.379 g g(-1), respectively), which was statistically similar to the use of 0.75% NaOH (0.763 g g(-1) and 0.358 g g(-1), respectively). Thus, solid-state pretreatment with 0.75% NaOH and powder-state hydrolysis appear to be suitable for fermentation and bioethanol production from rice straw.

Comparison of Dilution, Filtration, and Microwave Digestion Sample Pretreatments in Elemental Profiling of Wine by ICP-MS.

PubMed

Godshaw, Joshua; Hopfer, Helene; Nelson, Jenny; Ebeler, Susan E

2017-09-25

Wine elemental composition varies by cultivar, geographic origin, viticultural and enological practices, and is often used for authenticity validation. Elemental analysis of wine by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is challenging due to the potential for non-spectral interferences and plasma instability arising from organic matrix components. Sample preparation mitigates these interferences, however, conflicting recommendations of best practices in ICP-MS analysis of wine have been reported. This study compared direct dilution, microwave-assisted acid digestion, and two filtration sample pretreatments, acidification prior to filtration and filtration followed by acidification, in elemental profiling of one white and three red table wines by ICP-MS. Of 43 monitored isotopes, 37 varied by sample preparation method, with significantly higher results of 17 isotopes in the microwave-digested samples. Both filtration treatments resulted in lower results for 11 isotopes compared to the other methods. Finally, isotope dilution determination of copper based on natural abundances and the 63 Cu: 65 Cu instrument response ratio agreed with external calibration and confirmed a significant sample preparation effect. Overall, microwave digestion did not compare favorably, and direct dilution was found to provide the best compromise between ease of use and result accuracy and precision, although all preparation strategies were able to differentiate the wines.

Effects of pretreatment processes for Zr electrorefining of oxidized Zircaloy-4 cladding tubes

NASA Astrophysics Data System (ADS)

Hwa Lee, Chang; Lee, Yoo Lee; Jeon, Min Ku; Choi, Yong Taek; Kang, Kweon Ho; Park, Geun Il

2014-06-01

The effect of pretreatment processes for the Zr electrorefining of oxidized Zircaloy-4 cladding tubes is examined in LiCl-KCl-ZrCl4 molten salts at 500 °C. The cyclic voltammetries reveal that the Zr dissolution kinetics is highly dependent on the thickness of a Zr oxide layer formed at 500 °C under air atmosphere. For the Zircaloy-4 tube covered with a 1 μm thick oxide layer, the Zr dissolution process is initiated from a non-stoichiometric Zr oxide surface through salt treatment at an open circuit potential in the molten salt electrolyte. The Zr dissolution of the samples in the middle range of oxide layer thickness appears to be more effectively derived by the salt treatment coupled with an anodic potential application at an oxidation potential of Zr. A modification of the process scheme offers an applicability of Zr electrorefining for the treatment of oxidized cladding hull wastes.

Effect of cryopreservation on the pre-hatching behavior in the Mexican fruit fly Anastrepha ludens Loew (Diptera, Tephritidae).

PubMed

Rajamohan, Arun; Rinehart, Joseph P; Leopold, Roger A

2018-02-01

In a sampling of untreated embryos of the economically important fruit pest species, Anastrepha ludens, the cumulative hatch percentage in the lab was noted to be ∼85%. Approximately 70% of the larvae had eclosed through the posterior pole of the egg. This process is effected by the act of Pole Reversal (PR) of the fully developed pre-hatch larva from the wider anterior to the narrower posterior pole of the egg. Investigation of the effects of cryopreservation and various pretreatments prior to cryostorage on the PR behavior was prompted by the observation of significantly lower proportion of cryopreserved embryos exhibiting the PR behavior. Pretreatments (dechorionation and permeabilization) followed by vitrification resulted in delayed hatching, reflecting a slower embryonic development rate of ∼10 h. A smaller proportion of the treated embryos either eclosed from the anterior end of the egg or did not eclose at all despite complete development and prehatch gnawing activity. In the untreated controls, 24.0% of the embryos eclosed from the anterior pole. After permeabilization and cryopreservation, 83% and 55% (adjusted hatch) of the embryos were noted to hatch this way, respectively. An analysis of the hatch count after the treatments shows that factors contributing to the embryos' inability to properly invert polarity is not solely due to cryopreservation but also due to the pretreatment procedures including dechorionation and permeabilization. In fact, the permeabilization pre-treatment contributed the highest to this phenomenon lending support to the view that chemical toxicity rather than physical effects of cryopreservation play a major role in post-cryopreservation effects. Published by Elsevier Inc.

Evaluation of High Solids Alkaline Pretreatment of Rice Straw

PubMed Central

Cheng, Yu-Shen; Zheng, Yi; Yu, Chao Wei; Dooley, Todd M.; Jenkins, Bryan M.

2010-01-01

Fresh-harvested, air-dried rice straw was pretreated at a water content of 5 g H2O/g straw using sodium hydroxide (NaOH) and compared to pretreatment at 10 g H2O/g straw by hydrated lime (Ca(OH)2). Full factorial experiments including parallel wash-only treatments were completed with both sources of alkali. The experiments were designed to measure the effects of alkaline loading and pretreatment time on delignification and sugar yield upon enzymatic hydrolysis. Reaction temperature was held constant at 95°C for lime pretreatment and 55°C for NaOH pretreatment. The range of delignification was 13.1% to 27.0% for lime pretreatments and was 8.6% to 23.1% for NaOH pretreatments. Both alkaline loading and reaction time had significant positive effects (p < 0.001) on delignification under the design conditions, but only alkaline loading had a significant positive effect on enzymatic hydrolysis. Treatment at higher temperature also improved delignification; delignification with water alone ranged from 9.9% to 14.5% for pretreatment at 95°C, but there was little effect observed at 55°C. Post-pretreatment washing of biomass was not necessary for subsequent enzymatic hydrolysis. Maximum glucose yields were 176.3 mg/g dried biomass (48.5% conversion efficiency of total glucose) in lime-pretreated and unwashed biomass and were 142.3 mg/g dried biomass (39.2% conversion efficiency of total glucose) in NaOH-pretreated and unwashed biomass. PMID:20440580

Development of an improved rapid BACpro® protocol and a method for direct identification from blood-culture-positive bottles using matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

PubMed

Yonezawa, Takatoshi; Watari, Tomohisa; Ashizawa, Kazuho; Hanada, Daisuke; Yanagiya, Takako; Watanabe, Naoki; Terada, Takashi; Tomoda, Yutaka; Fujii, Satoshi

2018-05-01

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been incorporated into pathogenic bacterial identification methods and has improved their rapidity. Various methods have been reported to directly identify bacteria with MALDI-TOF MS by pretreating culture medium in blood culture bottles. Rapid BACpro® (Nittobo Medical Co., Ltd.) is a pretreatment kit for effective collection of bacteria with cationic copolymers. However, the Rapid BACpro® pretreatment kit is adapted only for MALDI Biotyper (Bruker Daltonics K.K.), and there has been a desire to expand its use to VITEK MS (VMS; bioMerieux SA). We improved the protocol and made it possible to analyze with VMS. The culture medium bacteria collection method was changed to a method with centrifugation after hemolysis using saponin; the cationic copolymer concentration was changed to 30% of the original concentration; the sequence with which reagents were added was changed; and a change was made to an ethanol/formic acid extraction method. The improved protocol enhanced the identification performance. When VMS was used, the identification rate was 100% with control samples. With clinical samples, the identification agreement rate with the cell smear method was 96.3%. The improved protocol is effective in blood culture rapid identification, being both simpler and having an improved identification performance compared with the original. Copyright © 2018 Elsevier B.V. All rights reserved.

Levosimendan: A Cardiovascular Drug to Prevent Liver Ischemia-Reperfusion Injury?

PubMed Central

Fulop, Andras; Rosero, Oliver; Garbaisz, David; Turoczi, Zsolt; Lotz, Gabor; Rakonczay, Zoltan; Balla, Zsolt; Hegedus, Viktor; Harsanyi, Laszlo; Szijarto, Attila

2013-01-01

Introduction Temporary occlusion of the hepatoduodenal ligament leads to an ischemic-reperfusion (IR) injury in the liver. Levosimendan is a new positive inotropic drug, which induces preconditioning-like adaptive mechanisms due to opening of mitochondrial KATP channels. The aim of this study was to examine possible protective effects of levosimendan in a rat model of hepatic IR injury. Material and Methods Levosimendan was administered to male Wistar rats 1 hour (early pretreatment) or 24 hours (late pretreatment) before induction of 60-minute segmental liver ischemia. Microcirculation of the liver was monitored by laser Doppler flowmeter. After 24 hours of reperfusion, liver and blood samples were taken for histology, immuno- and enzyme-histochemistry (TUNEL; PARP; NADH-TR) as well as for laboratory tests. Furthermore, liver antioxidant status was assessed and HSP72 expression was measured. Results In both groups pretreated with levosimendan, significantly better hepatic microcirculation was observed compared to respective IR control groups. Similarly, histological damage was also reduced after levosimendan administration. This observation was supported by significantly lower activities of serum ALT (pearly = 0.02; plate = 0.005), AST (pearly = 0.02; plate = 0.004) and less DNA damage by TUNEL test (pearly = 0.05; plate = 0.034) and PAR positivity (pearly = 0.02; plate = 0.04). Levosimendan pretreatment resulted in significant improvement of liver redox homeostasis. Further, significantly better mitochondrial function was detected in animals receiving late pretreatment. Finally, HSP72 expression was increased by IR injury, but it was not affected by levosimendan pretreatment. Conclusion Levosimendan pretreatment can be hepatoprotective and it could be useful before extensive liver resection. PMID:24040056

Nano- and microcrystalline diamond deposition on pretreated WC-Co substrates: structural properties and adhesion

NASA Astrophysics Data System (ADS)

Fraga, M. A.; Contin, A.; Rodríguez, L. A. A.; Vieira, J.; Campos, R. A.; Corat, E. J.; Trava Airoldi, V. J.

2016-02-01

Many developments have been made to improve the quality and adherence of CVD diamond films onto WC-Co hard metal tools by the removing the cobalt from the substrate surface through substrate pretreatments. Here we compare the efficiency of three chemical pretreatments of WC-Co substrates for this purpose. First, the work was focused on a detailed study of the composition and structure of as-polished and pretreated substrate surfaces to characterize the effects of the substrate preparation. Considering this objective, a set of WC-9% Co substrates, before and after pretreatment, was analyzed by FEG-SEM, EDS and x-ray diffraction (XRD). The second stage of the work was devoted to the evaluation of the influence of seeding process, using 4 nm diamond nanoparticles, on the morphology and roughness of the pretreated substrates. The last and most important stage was to deposit diamond coatings with different crystallite sizes (nano and micro) by hot-filament CVD to understand fully the mechanism of growth and adhesion of CVD diamond films on pretreated WC-Co substrates. The transition from nano to microcrystalline diamond was achieved by controlling the CH4/H2 gas ratio. The nano and microcrystalline samples were grown under same time at different substrate temperatures 600 °C and 800 °C, respectively. The different substrate temperatures allowed the analysis of the cobalt diffusion from the bulk to the substrate surface during CVD film growth. Furthermore, it was possible to evaluate how the coating adhesion is affected by the diffusion. The diamond coatings were characterized by Raman spectroscopy, XRD, EDS, FEG-SEM, atomic force microscope and 1500 N Rockwell indentation to evaluate the adhesion.

Effect of acid detergent fiber in hydrothermally pretreated sewage sludge on anaerobic digestion process

NASA Astrophysics Data System (ADS)

Takasaki, Rikiya; Yuan, Lee Chang; Kamahara, Hirotsugu; Atsuta, Youichi; Daimon, Hiroyuki

2017-10-01

Hydrothermal treatment is one of the pre-treatment method for anaerobic digestion. The application of hydrothermal treatment to sewage sludge of wastewater treatment plant has been succeeded to enhance the biogas production. The purpose of this study is to quantitatively clarify the effect of hydrothermal treatment on anaerobic digestion process focusing on acid detergent fiber (ADF) in sewage sludge, which is low biodegradability. The hydrothermal treatment experiment was carried out for 15 minutes between 160 °C and 200 °C respectively. The ADF content was decreased after hydrothermal treatment compared with untreated sludge. However, ADF content was increased when raising the treatment temperature from 160 °C to 200 °C. During batch anaerobic digestion experiment, untreated and treated sludge were examined for 10 days under 38 °C, and all samples were fed once based on volatile solids of samples. From batch anaerobic digestion experiment, as ADF content in sewage sludge increased, the total biogas production decreased. It was found that ADF content in sewage sludge influence on anaerobic digestion. Therefore, ADF could be one of the indicator to evaluate the effect of hydrothermal treatment to sewage sludge on anaerobic digestion.

Surface-enhanced Raman spectroscopy studies of yellow organic dyestuffs and lake pigments in oil paint.

PubMed

Mayhew, Hannah E; Fabian, David M; Svoboda, Shelley A; Wustholz, Kristin L

2013-08-21

Identifying natural, organic dyes and pigments is important for the conservation, preservation, and historical interpretation of works of art. Although previous SERS studies have demonstrated high sensitivity and selectivity for red lake pigments using various pretreatment conditions, corresponding investigations of yellow lake pigments and paints are relatively sparse. Here, surface-enhanced Raman scattering (SERS) spectroscopy is used to identify a variety of yellow organic dyestuffs and lake pigments in oil paint. High-quality SERS spectra of yellow dyestuffs (i.e., turmeric, old fustic, Buckthorn berries) and corresponding paints could be obtained with or without sample pretreatment using microliter quantities of HCl and methanol at room temperature. However, the SERS spectra of yellow lake pigments (i.e., Stil de Grain, Reseda lake) and their corresponding oil paints were only observed upon sample pretreatment. Ultimately, we demonstrate a reliable sample treatment protocol for SERS-based identification of turmeric, old fustic, Buckthorn berries, Stil de Grain, and Reseda lake as well as for microscopic samples of the corresponding oil paints.

Platform construction and extraction mechanism study of magnetic mixed hemimicelles solid-phase extraction

NASA Astrophysics Data System (ADS)

Xiao, Deli; Zhang, Chan; He, Jia; Zeng, Rong; Chen, Rong; He, Hua

2016-12-01

Simple, accurate and high-throughput pretreatment method would facilitate large-scale studies of trace analysis in complex samples. Magnetic mixed hemimicelles solid-phase extraction has the power to become a key pretreatment method in biological, environmental and clinical research. However, lacking of experimental predictability and unsharpness of extraction mechanism limit the development of this promising method. Herein, this work tries to establish theoretical-based experimental designs for extraction of trace analytes from complex samples using magnetic mixed hemimicelles solid-phase extraction. We selected three categories and six sub-types of compounds for systematic comparative study of extraction mechanism, and comprehensively illustrated the roles of different force (hydrophobic interaction, π-π stacking interactions, hydrogen-bonding interaction, electrostatic interaction) for the first time. What’s more, the application guidelines for supporting materials, surfactants and sample matrix were also summarized. The extraction mechanism and platform established in the study render its future promising for foreseeable and efficient pretreatment under theoretical based experimental design for trace analytes from environmental, biological and clinical samples.

Piezoelectric immunochip for the detection of dengue fever in viremia phase.

PubMed

Wu, Tzong-Zeng; Su, Chih-Cheng; Chen, Li-Kuang; Yang, Hui-Hua; Tai, Dar-Fu; Peng, Kou-Cheng

2005-11-15

The global prevalence of dengue fever has grown so dramatically in recent years that it is endemic in more than 100 countries and has become a major international public health concern. Moreover, since the flu-like symptoms that accompany dengue fever are atypical and varied, the detection procedures currently used to identify it are cumbersome and time-consuming, making early stage epidemiological control and effective medical treatment of this epidemic almost impossible. In this study, a QCM-based detection system was developed in which two monoclonal antibodies against dengue E and NS-1 protein, respectively, were control orientated immobilized on QCM via protein A to produce an immunochip. Various sample pretreatment procedures were evaluated to ascertain the most suitable combination, and both the simulating samples and the clinical specimen were examined by the immunochip. The results revealed that the cibacron blue 3GA gel-heat denature (CB-HD) method was the most effective sample pretreatment technique. Due to the complex composition of the serum, the immunochip could only effectively quantify dengue viral antigens in a 1/1000 untreated simulated sample. With the help of the CB-HD method, the dilution folds were found to capable of being reduced from 1000 to 100, and the detection limit lowered to 1.727 microg/ml (E protein) and 0.740 microg/ml (NS-1 protein) in the original sample. While the cocktail immunochip could not quantify both antigens separately, the higher signal level rendered it a more effective qualification tool for suspect screening. Moreover, the results of the analysis of clinical specimens also proved the ability and future potential of cocktail immunochip in discriminating dengue-positive cases from negative serum specimens in the viremia phase.

Microbial pretreatment of cotton stalks by Phanerochaete chrysosporium for bioethanol production

NASA Astrophysics Data System (ADS)

Shi, Jian

Lignocellulosic biomass has been recognized as a widespread, potentially low cost renewable source of mixed sugars for fermentation to fuel ethanol. Pretreatment, as the first step towards conversion of lignocellulose to ethanol, remains one of the main barriers to technical and commercial success of the processing technology. Existing pretreatment methods have largely been developed on the basis of physiochemical technologies which are considered relatively expensive and usually involve adverse environmental impacts. In this study, an environmentally benign alternative, microbial pretreatment using Phanerochaete chrysosporium, was explored to degrade lignin in cotton stalks and facilitate their conversion into ethanol. Two submerged liquid pretreatment techniques (SmC), shallow stationary and agitated cultivation, at three inorganic salt concentrations (no salts, modified salts without Mn2+, modified salts with Mn2+) were compared by evaluating their pretreatment efficiencies. Shallow stationary cultivation with no salt was superior to other pretreatment conditions and gave 20.7% lignin degradation along with 76.3% solids recovery and 29.0% carbohydrate availability over a 14 day period. The influence of substrate moisture content (65%, 75% and 80% M.C. wet-basis), inorganic salt concentration (no salts, modified salts without Mn2+ , modified salts with Mn2+) and culture time (0-14 days) on pretreatment effectiveness in solid state (SSC) systems was also examined. It was shown that solid state cultivation at 75% M.C. without salts was the most preferable pretreatment resulting in 27.6% lignin degradation, 71.1% solids recovery and 41.6% carbohydrate availability over a period of 14 days. A study on hydrolysis and fermentation of cotton stalks treated microbially using the most promising SmC (shallow stationary, no salts) and SSC (75% moisture content, no salts) methods resulted in no increase in cellulose conversion with direct enzyme application (10.98% and 3.04% for SmC and SSC pretreated samples, respectively) compared with untreated cotton stalk samples (17.93%). Washing of pretreated cotton stalks alone caused no significant increase in cellulose conversion. However, a heat treatment (autoclaving) followed by washing remarkably improved (P<0.05) cellulose conversion to 14.94% and 17.81% for SmC and SSC pretreatment, respectively. Mathematical models describing holocellulose consumption, lignin degradation, cellulase and ligninolytic enzyme production, and oxygen uptake associated with the growth of P. chrysosporium during 14 days fungal pretreatment were developed. For SmC pretreatment, model parameters were estimated by nonlinear regression and validated using an independent set of experimental data. Models yielded sufficiently accurate predictions for holocellulose consumption (R2=0.9772 and 0.9837, 1d and 3d oxygen flushing, respectively), lignin degradation (R2=0.9879 and 0.8682) and ligninolytic enzyme production (R2=0.8135 and 0.9693) under both 1 and 3d oxygen flushing conditions. However, the prediction capabilities for fungal growth (1d and 3d), cellulase production (3d) and oxygen uptake (3d) were limited. For SSC, the models were established in three phases (I: day 0-4, II: day 4-7, III: day 7-14). After validation it was shown that the developed models can yield sufficiently accurate predictions for fungal growth (R 2=0.9724), holocellulose consumption (R2=0.9686), lignin degradation (R2=0.9309) and ligninolytic enzyme production (R2=0.9203); however predictions of cellulase production were fair (R2=0.6133). Although significant delignification occurred during fungal pretreatment indicating the presence of ligninolytic enzymes, common spectrophotometric enzyme assays failed to detect lignin peroxidase (LiP) and manganese peroxidase (MnP) activities in fungal pretreatment cultures. Efforts were made to overcome the drawbacks of standardized assays by performing protein gel electrophoresis and crude enzyme delignification studies. Results from this research are expected to be beneficial in the development of pretreatment technologies that are environment friendly and utilize naturally occurring microorganisms.

Glass transition temperature of dried lens tissue pretreated with trehalose, maltose, or cyclic tetrasaccharide.

PubMed

Kawata, Tetsuhiro; Matsuo, Toshihiko; Uchida, Tetsuya

2014-01-01

Glass transition temperature is a main indicator for amorphous polymers and biological macromolecules as materials, and would be a key for understanding the role of trehalose in protecting proteins and cells against desiccation. In this study, we measured the glass transition temperature by differential scanning calorimetry of dried lens tissues as a model of a whole biological tissue to know the effect of pretreatment by trehalose and other sugars. Isolated porcine lenses were incubated with saline, 100 or 1000 mM concentration of trehalose, maltose, or cyclic tetrasaccharide dissolved in saline at room temperature for 150 minutes. The solutions were removed and all samples were dried at room temperature in a desiccator until no weight change. The dried tissues were ground into powder and placed in a measuring pan for differential scanning calorimetry. The glass transition temperature of the dried lens tissues, as a mean and standard deviation, was 63.0 ± 6.4°C (n = 3) with saline pretreatment; 53.0 ± 0.8°C and 56.3 ± 2.7°C (n = 3), respectively, with 100 and 1000 mM trehalose pretreatment; 56.0 ± 1.6°C and 55.8 ± 1.1°C (n = 3), respectively, with 100 and 1000 mM maltose pretreatment; 60.0 ± 8.8°C and 59.2 ± 6.3°C (n = 3), respectively, with 100 and 1000 mM cyclic tetrasaccharide pretreatment. The glass transition temperature appeared lower, although not significantly, with trehalose and maltose pretreatments than with saline and cyclic tetrasaccharide pretreatments (P > 0.05, Kruskal-Wallis test). The glass transition temperature of the dried lens tissues with trehalose pretreatment appeared more noticeable on the thermogram, compared with other pretreatments. The glass transition temperature was measured for the first time in the dried lens tissues as an example of a whole biological tissue and might provide a basis for tissue preservation in the dried condition.

Size effects on acid bisulfite pretreatment efficiency: multiple product yields in spent liquor and enzymatic digestibility of pretreated solids

Treesearch

Yalan Liu; Jinwu Wang; Michael P. Wolcott

2017-01-01

Currently, feedstock size effects on chemical pretreatment performance were not clear due to the complexity of the pretreatment process and multiple evaluation standards such as the sugar recovery in spent liquor or enzymatic digestibility. In this study, we evaluated the size effects by various ways: the sugar recovery and coproduct yields in spent liquor, the...

Can washing-pretreatment eliminate the health risk of municipal solid waste incineration fly ash reuse?

PubMed

Wang, Yao; Pan, Yun; Zhang, Lingen; Yue, Yang; Zhou, Jizhi; Xu, Yunfeng; Qian, Guangren

2015-01-01

Although the reuse of washing-pretreated MSWI fly ash bas been a hot topic, the associated risk is still an issue of great concern. The present study investigated the influence of washing-pretreatment on the total contents and bioaccessibility of heavy metals in MSWI fly ash. Furthermore, the study incorporated bioaccessibility adjustment into probabilistic risk assessment, to quantify the health risk from multi-pathway exposure to the concerned chemicals as a result of reusing washed MSWI fly ash. The results revealed that both water-washing and acid-washing process have resulted in the concentrated heavy metal content, and have reduced the bioaccessibility of heavy metals. Besides, the acid-washing process increased the cancer risk in most cases, while the effect of water-washing process was uncertain. However, both water-washing and acid-washing pretreatment could decrease the hazard index based on bioaccesilbility. Despite the uncertainties accompanying these procedures, the results indicated that, in this application scenario, only water-washing or acid-washing process cannot reduce the actual risk from all samples to acceptable level, especially for cancer risk. Copyright © 2014. Published by Elsevier Inc.

Exploring Geographical Differentiation of the Hoelen Medicinal Mushroom, Wolfiporia extensa (Agaricomycetes), Using Fourier-Transform Infrared Spectroscopy Combined with Multivariate Analysis.

PubMed

Li, Yan; Zhang, Ji; Zhao, Yanli; Liu, Honggao; Wang, Yuanzhong; Jin, Hang

2016-01-01

In this study the geographical differentiation of dried sclerotia of the medicinal mushroom Wolfiporia extensa, obtained from different regions in Yunnan Province, China, was explored using Fourier-transform infrared (FT-IR) spectroscopy coupled with multivariate data analysis. The FT-IR spectra of 97 samples were obtained for wave numbers ranging from 4000 to 400 cm-1. Then, the fingerprint region of 1800-600 cm-1 of the FT-IR spectrum, rather than the full spectrum, was analyzed. Different pretreatments were applied on the spectra, and a discriminant analysis model based on the Mahalanobis distance was developed to select an optimal pretreatment combination. Two unsupervised pattern recognition procedures- principal component analysis and hierarchical cluster analysis-were applied to enhance the authenticity of discrimination of the specimens. The results showed that excellent classification could be obtained after optimizing spectral pretreatment. The tested samples were successfully discriminated according to their geographical locations. The chemical properties of dried sclerotia of W. extensa were clearly dependent on the mushroom's geographical origins. Furthermore, an interesting finding implied that the elevations of collection areas may have effects on the chemical components of wild W. extensa sclerotia. Overall, this study highlights the feasibility of FT-IR spectroscopy combined with multivariate data analysis in particular for exploring the distinction of different regional W. extensa sclerotia samples. This research could also serve as a basis for the exploitation and utilization of medicinal mushrooms.

[Protective effect of Uncaria rhynchophylla total alkaloids pretreatment on hippocampal neurons after acute hypoxia].

PubMed

Liu, Wei; Zhang, Zhao-qin; Zhao, Xiao-min; Gao, Yun-sheng

2006-05-01

To investigate the effect of Uncaria rhynchophylla total alkaloids (RTA) pretreatment on the voltage-gated sodium currents of the rat hippocampal neurons after acute hypoxia. Primary cultured hippocampal neurons were divided into RTA pre-treated and non-pretreated groups. Patch clamp whole-cell recording was used to compare the voltage-gated sodium current amplitude and threshold with those before hypoxia. After acute hypoxia, sodium current amplitude was significantly decreased and its threshold was upside. RTA pretreatment could inhibit the reduction of sodium current amplitude. RTA pretreatment alleviates the acute hypoxia-induced change of sodium currents, which may be one of the mechanisms for protective effect of RTA on cells.

Soil pretreatment and fast cell lysis for direct polymerase chain reaction from forest soils for terminal restriction fragment length polymorphism analysis of fungal communities

Treesearch

Fei Cheng; Lin Hou; Keith Woeste; Zhengchun Shang; Xiaobang Peng; Peng Zhao; Shuoxin Zhang

2016-01-01

Humic substances in soil DNA samples can influence the assessment of microbial diversity and community composition. Using multiple steps during or after cell lysis adds expenses, is time-consuming, and causes DNA loss. A pretreatment of soil samples and a single step DNA extraction may improve experimental results. In order to optimize a protocol for obtaining high...

The effects of levosimendan and glibenclamide on circulatory and metabolic variables in a canine model of acute hypoxia.

PubMed

Schwarte, Lothar A; Schwartges, Ingo; Thomas, Kai; Schober, Patrick; Picker, Olaf

2011-04-01

To study the effects of pretreatment with levosimendan (LEVO, a Ca²(+)-sensitizer and K (ATP) (+) channel opener) and/or the K (ATP) (+) channel antagonist glibenclamide (GLIB) on systemic hemodynamics, metabolism, and regional gastromucosal oxygenation during hypoxic hypoxemia. Chronically instrumented, healthy dogs (24-32 kg, n = 6 per group, randomized cross-over design) were repeatedly sedated, mechanically ventilated (FiO₂ ~0.3) and subjected to the following interventions: no pretreatment, LEVO pretreatment, GLIB pretreatment, or combined LEVO + GLIB pretreatment, each followed by hypoxic hypoxemia (FiO₂ ~0.1). We measured cardiac output (CO, ultrasonic flow probes), oxygen consumption (VO₂, indirect calorimetry), and gastromucosal microvascular hemoglobin oxygenation (μHbO₂, spectrophotometry). data are presented as mean ± SEM and compared by one-way ANOVA (direct drug effects within group) and two-way ANOVA (between all hypoxic conditions) both with Bonferroni corrections; p < 0.05. In LEVO-pretreated hypoxemia, CO was significantly higher compared to unpretreated hypoxemia. The increased CO was neither associated with an increased VO₂ nor with markers of aggravated anaerobiosis (pH, BE, lactate). In addition, LEVO pretreatment did not further compromise gastromucosal μHbO₂ in hypoxemia. After combined LEVO + GLIB pretreatment, systemic effects of GLIB were apparent, however, CO was significantly higher than during unpretreated and GLIB-pretreated hypoxemia, but equal to LEVO-pretreated hypoxemia, indicating that GLIB did not prevent the increased CO in LEVO-pretreated hypoxia. LEVO pretreatment resulted in improved systemic circulation (CO) during hypoxemia without fueling systemic VO₂, without aggravating systemic anaerobiosis markers, and without further compromising microvascular gastromucosal oxygenation. Thus, LEVO pretreatment may be an option to support the systemic circulation during hypoxia.

Simple and Sensitive Paper-Based Device Coupling Electrochemical Sample Pretreatment and Colorimetric Detection.

PubMed

Silva, Thalita G; de Araujo, William R; Muñoz, Rodrigo A A; Richter, Eduardo M; Santana, Mário H P; Coltro, Wendell K T; Paixão, Thiago R L C

2016-05-17

We report the development of a simple, portable, low-cost, high-throughput visual colorimetric paper-based analytical device for the detection of procaine in seized cocaine samples. The interference of most common cutting agents found in cocaine samples was verified, and a novel electrochemical approach was used for sample pretreatment in order to increase the selectivity. Under the optimized experimental conditions, a linear analytical curve was obtained for procaine concentrations ranging from 5 to 60 μmol L(-1), with a detection limit of 0.9 μmol L(-1). The accuracy of the proposed method was evaluated using seized cocaine samples and an addition and recovery protocol.

Dispersive Solid Phase Extraction for the Analysis of Veterinary Drugs Applied to Food Samples: A Review

PubMed Central

Islas, Gabriela; Hernandez, Prisciliano

2017-01-01

To achieve analytical success, it is necessary to develop thorough clean-up procedures to extract analytes from the matrix. Dispersive solid phase extraction (DSPE) has been used as a pretreatment technique for the analysis of several compounds. This technique is based on the dispersion of a solid sorbent in liquid samples in the extraction isolation and clean-up of different analytes from complex matrices. DSPE has found a wide range of applications in several fields, and it is considered to be a selective, robust, and versatile technique. The applications of dispersive techniques in the analysis of veterinary drugs in different matrices involve magnetic sorbents, molecularly imprinted polymers, carbon-based nanomaterials, and the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method. Techniques based on DSPE permit minimization of additional steps such as precipitation, centrifugation, and filtration, which decreases the manipulation of the sample. In this review, we describe the main procedures used for synthesis, characterization, and application of this pretreatment technique and how it has been applied to food analysis. PMID:29181027

Color and alcohol removal for the simultaneous detection of amino acids and sugars in wine by two-dimensional ion chromatography.

PubMed

Fa, Yun; Liu, Yinghui; Xu, Aihua; Yu, Yuexue; Li, Fangfang; Liu, Huizhou

2017-09-15

An effective pretreatment method for wine color removal by a PS-DVB SPE cartridge and online alcohol elimination by valve switching was presented. The optimum parameters for color removal were investigated: 40-μm and 100Å poly (styrene)-divinylbenzene (PS-DVB) (0.4g) was selected as the color removal material and 5mL of ethanol (10%) as the elution solvent for sample pretreatment under given condition. Moreover, an accurate and automated two-dimensional ion chromatography method for the simultaneous detection of amino acids and sugars was achieved with two valves after injection without alcohol interference. The method had a mean correlation coefficient of >0.99 and a repeatability of 0.92%-4.30% for eight replicates. The mean recovery of six red wine samples were 97.6%, 96.6%, 96.1%, 95.9%, 97.3% and 96.4% respectively. And this method successfully analyzed the amino acid and sugar contents of six wine samples of different origins. Copyright © 2017. Published by Elsevier B.V.

Quantitative (13)C MultiCP solid-state NMR as a tool for evaluation of cellulose crystallinity index measured directly inside sugarcane biomass.

PubMed

Bernardinelli, Oigres Daniel; Lima, Marisa Aparecida; Rezende, Camila Alves; Polikarpov, Igor; deAzevedo, Eduardo Ribeiro

2015-01-01

The crystallinity index (CI) is often associated with changes in cellulose structure after biological and physicochemical pretreatments. While some results obtained with lignocellulosic biomass demonstrate a progressive increase in the CI as a function of pretreatments, it is also shown that the CI can significantly vary depending on the choice of the measurement method. Besides, the influence of the CI on the recalcitrance of biomass has been controversial for a long time, but the most recent results tend to point out that the efficiency of pretreatments in reducing the recalcitrance is not clearly correlated with the decrease of the CI. Much of this controversy is somewhat associated with the inability to distinguish between the CI of the cellulose inside the biomass and the CI of the full biomass, which contains other amorphous components such as lignin and hemicellulose. Cross polarization by multiple contact periods (Multi-CP) method was used to obtain quantitative (13)C solid-state nuclear magnetic resonance (ssNMR) spectra of sugarcane bagasse biomass submitted to two-step pretreatments and/or enzymatic hydrolysis. By comparing the dipolar filtered Multi-CP (13)C NMR spectra of untreated bagasse samples with those of samples submitted to acid pretreatment, we show that a 1% H2SO4-assisted pretreatment was very effective in removing practically all the hemicellulose signals. This led us to propose a spectral editing procedure based on the subtraction of MultiCP spectra of acid-treated biomass from that of the extracted lignin, to obtain a virtually pure cellulose spectrum. Based on this idea, we were able to evaluate the CI of the native cellulose inside the sugarcane bagasse biomass. The results show the validity of the proposed method as a tool for evaluating the variations in the CI of the cellulose inside biomasses of similar kinds. Despite a clear increase in the CI of biomass as measured by X-ray diffraction, no significant variations were observed in the CI of the cellulose inside the biomass after a particular 1% H2SO4/0.25-4% NaOH chemical-assisted pretreatments. The CI of cellulose inside the biomass solid fraction that remained after the enzymatic hydrolysis was also evaluated. The results show a slight increase in crystallinity.

Low melting point pyridinium ionic liquid pretreatment for enhancing enzymatic saccharification of cellulosic biomass.

PubMed

Uju; Nakamoto, Aya; Shoda, Yasuhiro; Goto, Masahiro; Tokuhara, Wataru; Noritake, Yoshiyuki; Katahira, Satoshi; Ishida, Nobuhiro; Ogino, Chiaki; Kamiya, Noriho

2013-05-01

The potential of 1-hexylpyridinium chloride ([Hpy][Cl]), to pretreat cellulosic feedstocks was investigated using microcrystalline cellulose (Avicel) and Bagasse at 80 °C or 100 °C. Short [Hpy][Cl] pretreatments, <30 min, at lower temperature accelerate subsequent enzymatic saccharification of Avicel. Over 95% conversion of pretreated Avicel to glucose was attained after 24h enzymatic saccharification under optimal conditions, whereas regenerated Bagasse showed 1-3-fold higher conversion than untreated biomass. FT-IR analysis of both Avicel and Bagasse samples pretreated with [Hpy][Cl] or 1-ethyl-3-methyimidazolium acetate ([Emim][OAc]) revealed that these ionic liquids behaved differently during pretreatment. [Hpy][Cl] pretreatment for an extended duration (180 min) released mono- and disaccharides without using cellulase enzymes, suggesting [Hpy][Cl] has capability for direct saccharification of cellulosic feedstocks. On the basis of the results obtained, [Hpy][Cl] pretreatment enhanced initial reaction rates in enzymatic saccharification by either crystalline polymorphic alteration of cellulose or partial degradation of the crystalline cellulosic fraction in biomass. Copyright © 2012 Elsevier Ltd. All rights reserved.

Cellulose nanocrystals from grape pomace: Production, properties and cytotoxicity assessment.

PubMed

Coelho, Caroline C S; Michelin, Michele; Cerqueira, Miguel A; Gonçalves, Catarina; Tonon, Renata V; Pastrana, Lorenzo M; Freitas-Silva, Otniel; Vicente, António A; Cabral, Lourdes M C; Teixeira, José A

2018-07-15

Cellulose nanocrystals (CNCs) were obtained from grape pomace through chemical and physical pretreatments. Bleached cellulose pulp was subjected to acid hydrolysis (AH) for 30 or 60 min and an ultrasound treatment to obtain CNCs (AH 30S and AH 60S ). Compositional analyses of untreated (UGP) and pretreated (PGP) grape pomace showed the effectiveness of pretreatment in removing non-cellulosic components, recovering 80.1% cellulose in PGP (compared to 19.3% of UGP). Scanning and transmission electron microscopies were used to evaluate the CNCs morphology. AH in combination with ultrasound treatment led to needle-shaped structures and apparently more dispersed suspensions. Crystallinity index and thermal stability were studied by X-ray diffraction and thermogravimetric analysis, respectively. The AH 60S sample presented high aspect ratio, crystallinity and thermal stability. CNCs toxicity was evaluated by exposing Caco-2 cells to CNCs suspension and evaluating their viability. Results showed that CNCs are non-toxic, opening the opportunity for their use on food and pharmaceutical applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

The effects of substrate pre-treatment on anaerobic digestion systems: a review.

PubMed

Carlsson, My; Lagerkvist, Anders; Morgan-Sagastume, Fernando

2012-09-01

Focus is placed on substrate pre-treatment in anaerobic digestion (AD) as a means of increasing biogas yields using today's diversified substrate sources. Current pre-treatment methods to improve AD are being examined with regard to their effects on different substrate types, highlighting approaches and associated challenges in evaluating substrate pre-treatment in AD systems and its influence on the overall system of evaluation. WWTP residues represent the substrate type that is most frequently assessed in pre-treatment studies, followed by energy crops/harvesting residues, organic fraction of municipal solid waste, organic waste from food industry and manure. The pre-treatment effects are complex and generally linked to substrate characteristics and pre-treatment mechanisms. Overall, substrates containing lignin or bacterial cells appear to be the most amendable to pre-treatment for enhancing AD. Approaches used to evaluate AD enhancement in different systems is further reviewed and challenges and opportunities for improved evaluations are identified. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of thermal, acid, alkaline and alkaline-peroxide pretreatments on the biochemical methane potential and kinetics of the anaerobic digestion of wheat straw and sugarcane bagasse.

PubMed

Bolado-Rodríguez, Silvia; Toquero, Cristina; Martín-Juárez, Judit; Travaini, Rodolfo; García-Encina, Pedro Antonio

2016-02-01

The effect of thermal, acid, alkaline and alkaline-peroxide pretreatments on the methane produced by the anaerobic digestion of wheat straw (WS) and sugarcane bagasse (SCB) was studied, using whole slurry and solid fraction. All the pretreatments released formic and acetic acids and phenolic compounds, while 5-hydroxymetilfurfural (HMF) and furfural were generated only by acid pretreatment. A remarkable inhibition was found in most of the whole slurry experiments, except in thermal pretreatment which improved methane production compared to the raw materials (29% for WS and 11% for SCB). The alkaline pretreatment increased biodegradability (around 30%) and methane production rate of the solid fraction of both pretreated substrates. Methane production results were fitted using first order or modified Gompertz equations, or a novel model combining both equations. The model parameters provided information about substrate availability, controlling step and inhibitory effect of compounds generated by each pretreatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Solar assisted alkali pretreatment of garden biomass: Effects on lignocellulose degradation, enzymatic hydrolysis, crystallinity and ultra-structural changes in lignocellulose.

PubMed

Gabhane, Jagdish; William, S P M Prince; Vaidya, Atul N; Das, Sera; Wate, Satish R

2015-06-01

A comprehensive study was carried out to assess the effectiveness of solar assisted alkali pretreatment (SAAP) on garden biomass (GB). The pretreatment efficiency was assessed based on lignocellulose degradation, conversion of cellulose into reducing sugars, changes in the ultra-structure and functional groups of lignocellulose and impact on the crystallinity of cellulose, etc. SAAP was found to be efficient for the removal of lignin and hemicellulose that facilitated enzymatic hydrolysis of cellulose. FTIR and XRD studies provided details on the effectiveness of SAAP on lignocellulosic moiety and crystallinity of cellulose. Scanning electron microscopic analysis showed ultra-structural disturbances in the microfibrils of GB as a result of pretreatment. The mass balance closer of 97.87% after pretreatment confirmed the reliability of SAAP pretreatment. Based on the results, it is concluded that SAAP is not only an efficient means of pretreatment but also economical as it involved no energy expenditure for heat generation during pretreatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pretreatment HIV-drug resistance in Mexico and its impact on the effectiveness of first-line antiretroviral therapy: a nationally representative 2015 WHO survey.

PubMed

Ávila-Ríos, Santiago; García-Morales, Claudia; Matías-Florentino, Margarita; Romero-Mora, Karla A; Tapia-Trejo, Daniela; Quiroz-Morales, Verónica S; Reyes-Gopar, Helena; Ji, Hezhao; Sandstrom, Paul; Casillas-Rodríguez, Jesús; Sierra-Madero, Juan; León-Juárez, Eddie A; Valenzuela-Lara, Marisol; Magis-Rodríguez, Carlos; Uribe-Zuñiga, Patricia; Reyes-Terán, Gustavo

2016-12-01

WHO has developed a global HIV-drug resistance surveillance strategy, including assessment of pretreatment HIV-drug resistance. We aimed to do a nationally representative survey of pretreatment HIV-drug resistance in Mexico using WHO-recommended methods. Among 161 Ministry of Health antiretroviral therapy (ART) clinics in Mexico, the largest, including 90% of ART initiators within the Ministry of Health (66 in total), were eligible for the survey. We used a probability-proportional-to-size design method to sample 25 clinics throughout the country. Consecutive ART-naive patients with HIV about to initiate treatment were invited to participate in the survey; individuals with previous exposure to ART were excluded. We assessed pretreatment HIV-drug resistance by Sanger sequencing and next-generation sequencing of viruses from plasma specimens from eligible participants with Stanford University HIV Drug Resistance Database methods. We obtained follow-up data for a median of 9·4 months (range 6-12) after enrolment. We investigated possible relations between demographic variables and pretreatment drug resistance with univariate and multivariate logistic regression. Between Feb 3 and July 30, 2015, we screened 288 patients in 25 clinics, from whom 264 provided successfully sequenced viruses with no evidence of current exposure to antiretroviral drugs. With the Sanger method, of these 264 participants, 41 (15·5%, 95% CI 11·4-20·5) had pretreatment resistance to any antiretroviral drug and 28 (10·6%, 7·2-15·0) had pretreatment resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs). At least low-level pretreatment resistance (Stanford penalty score ≥15) was noted in 13 (4 · 9%) of participants to efavirenz and in 23 (8·7%) to the combination tenofovir plus emtricitabine plus efavirenz. With next-generation sequencing, of 264 participants, 38 (14·4%, 95% CI 10·4-19·2) had pretreatment resistance to any antiretroviral drug and 26 (9·8%, 6·5-14·1) had pretreatment resistance to NNRTIs. After median follow-up of 8 months (IQR 6·5-9·4, range 5-11) after ART initiation, 97 (72%) of 135 NNRTI initiators achieved viral suppression (<50 copies per mL) compared with ten (40%) of 25 individuals who started with protease inhibitor-based regimens (p=0·0045). After multivariate regression considering pretreatment resistance and initial ART regimen as composite variables, people starting NNRTIs with pretreatment drug resistance achieved significantly lower viral suppression (odds ratio 0·24, 95% CI 0·07-0·74; p=0·014) than patients without NNRTI resistance. High levels of pretreatment drug resistance were noted in Mexico, and NNRTI pretreatment drug resistance significantly reduced the effectiveness of first-line ART regimens based on these drugs. Baseline HIV-drug resistance testing for initial ART follow-up and decision making should be considered. The Mexican Government and Consejo Nacional de Ciencia y Tecnología. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of alkaline pretreatment on anaerobic digestion of olive mill solid waste.

PubMed

Pellera, Frantseska-Maria; Santori, Sofia; Pomi, Raffaella; Polettini, Alessandra; Gidarakos, Evangelos

2016-12-01

The present study evaluates the influence of alkaline (NaOH) pretreatment on anaerobic digestion of olive pomace. Batch hydrolysis experiments with different NaOH dosages, process durations and temperatures were conducted, in which the variation of olive pomace solubilization in the liquid phase was investigated. The effect of pretreatment on anaerobic digestion was studied through biochemical methane potential assays. The results demonstrated the effectiveness of the NaOH pretreatment in improving olive pomace solubilization as well as its biodegradability. Maximum specific methane yields were achieved at different NaOH dosages depending on the pretreatment temperature. Consequently, it was concluded that the two operating parameters of the pretreatment stage (NaOH dosage and temperature) may exert a joint effect on substrate biodegradability and methane yields. The highest methane yield (242NmLCH 4 /gVS) was obtained for the material pretreated at 90°C, at a dosage of 1mmol/gVS (4% of VS). Copyright © 2016 Elsevier Ltd. All rights reserved.

Electroacupuncture pretreatment induces rapid tolerance to bupivacaine cardiotoxicity in rats.

PubMed

Gao, Jun-Long; Li, Yu-Lan; Wang, Xiu-Mei; Zhao, Qian-Long; Zhang, Hai-Jun; Han, Fang-Fang; Li, Xia-Xia; Zhang, Dong-Hang

2016-12-01

Evidence suggests that electroacupuncture (EA) protects against arrhythmia and myocardial injury induced by myocardial ischaemia-reperfusion. However, to our knowledge, it remains unknown whether EA could alleviate bupivacaine-induced cardiotoxicity. Therefore, we aimed to explore the effect of EA pretreatment on bupivacaine-induced cardiac arrest and outcomes of cardiopulmonary resuscitation (CPR) in rats. 24 adult male Sprague-Dawley rats were randomly divided into two groups: EA (n=12), and minimal acupuncture (MA) (n=12). Rats in both groups were needled at bilateral PC6, ST36, and ST40. Needles in the EA group were electrically stimulated for 60 min. ECG and invasive arterial blood pressure measurements were recorded. Two hours after EA or MA, 10 mg/kg bupivacaine was infused intravenously at a rate of 5 mg/kg/min in all rats. Rats suffering cardiac arrest were immediately subjected to CPR. At the end of the experiment, arterial blood samples were taken from surviving rats for blood gas analysis. The time from bupivacaine infusion until 20% prolongation of the QRS and QT interval, and the time to cardiac arrest, were notably increased among the rats pretreated with EA. Moreover, EA pretreatment significantly improved mean arterial pressure and heart rate at all monitored points after bupivacaine infusion. The proportion of animals surviving was higher in the EA group (9/12) than the MA group (3/12) at the end of experiment (p=0.039). Tolerance to bupivacaine-induced cardiotoxicity appeared to be increased following EA pre-treatment. The mechanism of action underlying the effects of EA on bupivacaine-induced cardiotoxicity requires further investigation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

A process to preserve valuable compounds and acquire essential oils from pomelo flavedo using a microwave irradiation treatment.

PubMed

Liu, Zaizhi; Zu, Yuangang; Yang, Lei

2017-06-01

A microwave pretreatment method was developed to preserve pectin, naringin, and limonin contents in pomelo flavedo to allow for longer storage times and subsequent extraction of pomelo essential oil. In terms of the essential oil, microwave pretreatment performed better than hydrodistillation with respect to extraction efficiency (1.88±0.06% in 24min versus 1.91±0.08% in 240min), oxygenation fraction (48.59±1.32% versus 29.63±1.02%), energy consumption (0.15kWh versus 1.54kWh), and environmental impact (123.20g CO 2 versus 1232g CO 2 ). Microwave-pretreated samples retained higher amounts of pectin, naringin, and limonin compared with non-pretreated samples. No obvious change in the degree of pectin esterification was observed. This study shows that the proposed process is a promising methodology for both preserving valuable compounds in pomelo flavedo during storage and acquiring essential oils. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterization of white poplar and eucalyptus after ionic liquid pretreatment as a function of biomass loading using X-ray diffraction and small angle neutron scattering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, Xueming; Duan, Yonghao; He, Lilin

A systematic study was done to understand interactions among biomass loading during ionic liquid (IL) pretreatment, biomass type and biomass structures. White poplar and eucalyptus samples were pretreated using 1-ethyl-3-methylimidazolium acetate (EmimOAc) at 110 °C for 3 h at biomass loadings of 5, 10, 15, 20 and 25 wt%. All of the samples were chemically characterized and tested for enzymatic hydrolysis. Physical structures including biomass crystallinity and porosity were measured by X-ray diffraction (XRD) and small angle neutron scattering (SANS), respectively. SANS detected pores of radii ranging from ~25 to 625 Å, enabling assessment of contributions of pores with different sizes to increased porositymore » after pretreatment. Contrasting dependences of sugar conversion on white poplar and eucalyptus as a function of biomass loading were observed and cellulose crystalline structure was found to play an important role.« less

A study of degradation resistance and cytocompatibility of super-hydrophobic coating on magnesium.

PubMed

Zhang, Yufen; Feyerabend, Frank; Tang, Shawei; Hu, Jin; Lu, Xiaopeng; Blawert, Carsten; Lin, Tiegui

2017-09-01

Calcium stearate based super-hydrophobic coating was deposited on plasma electrolytic oxidation (PEO) pre-treated magnesium substrate. The pre-treated magnesium and super-hydrophobic coating covered sample were characterized by scanning electron microscopy, X-ray diffraction and electrochemical corrosion measurements. The cytocompatibility and degradation resistance of magnesium, pre-treated magnesium and super-hydrophobic coating were analysed in terms of cell adhesion and osteoblast differentiation. The results indicate that the calcium stearate top coating shows super-hydrophobicity and that the surface is composed of micro/nanostructure. The super-hydrophobic coating covered sample shows higher barrier properties compared with the PEO pre-treated magnesium and bare magnesium. Human osteoblast proliferation, but not differentiation is enhanced by the PEO coating. Contrary, the super-hydrophobic coating reduces proliferation, but enhances differentiation of osteoblast, observable by the formation of hydroxyapatite. The combination of corrosion protection and cell reaction indicates that this system could be interesting for biomedical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of white poplar and eucalyptus after ionic liquid pretreatment as a function of biomass loading using X-ray diffraction and small angle neutron scattering.

PubMed

Yuan, Xueming; Duan, Yonghao; He, Lilin; Singh, Seema; Simmons, Blake; Cheng, Gang

2017-05-01

A systematic study was performed to understand interactions among biomass loading during ionic liquid (IL) pretreatment, biomass type and biomass structures. White poplar and eucalyptus samples were pretreated using 1-ethyl-3-methylimidazolium acetate (EmimOAc) at 110°C for 3h at biomass loadings of 5, 10, 15, 20 and 25wt%. All of the samples were chemically characterized and tested for enzymatic hydrolysis. Physical structures including biomass crystallinity and porosity were measured by X-ray diffraction (XRD) and small angle neutron scattering (SANS), respectively. SANS detected pores of radii ranging from ∼25 to 625Å, enabling assessment of contributions of pores with different sizes to increased porosity after pretreatment. Contrasting dependences of sugar conversion on white poplar and eucalyptus as a function of biomass loading were observed and cellulose crystalline structure was found to play an important role. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sequential high gravity ethanol fermentation and anaerobic digestion of steam explosion and organosolv pretreated corn stover.

PubMed

Katsimpouras, Constantinos; Zacharopoulou, Maria; Matsakas, Leonidas; Rova, Ulrika; Christakopoulos, Paul; Topakas, Evangelos

2017-11-01

The present work investigates the suitability of pretreated corn stover (CS) to serve as feedstock for high gravity (HG) ethanol production at solids-content of 24wt%. Steam explosion, with and without the addition of H 2 SO 4 , and organosolv pretreated CS samples underwent a liquefaction/saccharification step followed by simultaneous saccharification and fermentation (SSF). Maximum ethanol concentration of ca. 76g/L (78.3% ethanol yield) was obtained from steam exploded CS (SECS) with 0.2% H 2 SO 4 . Organosolv pretreated CS (OCS) also resulted in high ethanol concentration of ca. 65g/L (62.3% ethanol yield). Moreover, methane production through anaerobic digestion (AD) was conducted from fermentation residues and resulted in maximum methane yields of ca. 120 and 69mL/g volatile solids (VS) for SECS and OCS samples, respectively. The results indicated that the implementation of a liquefaction/saccharification step before SSF employing a liquefaction reactor seemed to handle HG conditions adequately. Copyright © 2017 Elsevier Ltd. All rights reserved.

How does cellulosome composition influence deconstruction of lignocellulosic substrates in Clostridium (Ruminiclostridium) thermocellum DSM 1313?

PubMed

Yoav, Shahar; Barak, Yoav; Shamshoum, Melina; Borovok, Ilya; Lamed, Raphael; Dassa, Bareket; Hadar, Yitzhak; Morag, Ely; Bayer, Edward A

2017-01-01

Bioethanol production processes involve enzymatic hydrolysis of pretreated lignocellulosic biomass into fermentable sugars. Due to the relatively high cost of enzyme production, the development of potent and cost-effective cellulolytic cocktails is critical for increasing the cost-effectiveness of bioethanol production. In this context, the multi-protein cellulolytic complex of Clostridium ( Ruminiclostridium ) thermocellum, the cellulosome, was studied here. C. thermocellum is known to assemble cellulosomes of various subunit (enzyme) compositions, in response to the available carbon source. In the current study, different carbon sources were used, and their influence on both cellulosomal composition and the resultant activity was investigated. Glucose, cellobiose, microcrystalline cellulose, alkaline-pretreated switchgrass, alkaline-pretreated corn stover, and dilute acid-pretreated corn stover were used as sole carbon sources in the growth media of C. thermocellum strain DSM 1313. The purified cellulosomes were compared for their activity on selected cellulosic substrates. Interestingly, cellulosomes derived from cells grown on lignocellulosic biomass showed no advantage in hydrolyzing the original carbon source used for their production. Instead, microcrystalline cellulose- and glucose-derived cellulosomes were equal or superior in their capacity to deconstruct lignocellulosic biomass. Mass spectrometry analysis revealed differential composition of catalytic and structural subunits (scaffoldins) in the different cellulosome samples. The most abundant catalytic subunits in all cellulosome types include Cel48S, Cel9K, Cel9Q, Cel9R, and Cel5G. Microcrystalline cellulose- and glucose-derived cellulosome samples showed higher endoglucanase-to-exoglucanase ratios and higher catalytic subunit-per-scaffoldin ratios compared to lignocellulose-derived cellulosome types. The results reported here highlight the finding that cellulosomes derived from cells grown on glucose and microcrystalline cellulose are more efficient in their action on cellulosic substrates than other cellulosome preparations. These results should be considered in the future development of C. thermocellum -based cellulolytic cocktails, designer cellulosomes, or engineering of improved strains for deconstruction of lignocellulosic biomass.

[Development of sample pretreatment techniques-rapid detection coupling methods for food security analysis].

PubMed

Huang, Yichun; Ding, Weiwei; Zhang, Zhuomin; Li, Gongke

2013-07-01

This paper summarizes the recent developments of the rapid detection methods for food security, such as sensors, optical techniques, portable spectral analysis, enzyme-linked immunosorbent assay, portable gas chromatograph, etc. Additionally, the applications of these rapid detection methods coupled with sample pretreatment techniques in real food security analysis are reviewed. The coupling technique has the potential to provide references to establish the selective, precise and quantitative rapid detection methods in food security analysis.

Performance evaluation of cross-flow membrane system for wastewater reuse from the wood-panels industry.

PubMed

Dizge, Nadir

2014-01-01

The objectives of this investigation were to perform a series of lab-scale membrane separation experiments under various operating conditions to investigate the performance behaviour of nanofiltration membrane (NF 270) for wastewater reuse from the wood-panels industry. The operating condition effects, e.g. cross-flow velocity (CFV), trans membrane pressure (TMP) and temperature, on the permeate flux and contaminant rejection efficiency were investigated. Moreover, three different samples: (1) raw wastewater collected from the wood-panels industry; (2) ultrafiltration pre-treated wastewater (UF-NF); and (3) coagulation/flocculation pre-treated wastewater (CF-NF) were employed in this study. The UF-NF was proposed as a pre-treatment process because it could reduce the chemical oxygen demand (COD) effectively with lower energy consumption than CF-NF. The performance of NF 270 membrane was assessed by measurements of the many parameters (pH, conductivity, total dissolved solids, COD, suspended solids, total nitrogen, nitrite, nitrate, and total phosphate) under various operating conditions. It was noted that the contaminant rejection was affected by changing TMP and CFV. It was concluded that the purified water stream can be recycled into the process for water reuse or safely disposed to the river.

Soil an-d nutrient loss following site preparation burning

Treesearch

E.A. Carter; J.P. Field; K.W. Farrish

2000-01-01

Sediment loss and nutrient cpncentrations in runoff were evaluated to determine the effects of site preparation burning on a recently harvested loblolly pine (Pinur taeda L.) site in east Texas. Sediment and nutrient losses prior to treatment were approximately the same from control plots and pretreatment burn plots. Nutrient analysis of runoff samples indicated that...

Effect of a single application of TiF(4) and NaF varnishes and solutions on dentin erosion in vitro.

PubMed

Magalhães, Ana Carolina; Levy, Flávia Mauad; Rios, Daniela; Buzalaf, Marília Afonso Rabelo

2010-02-01

This in vitro study aimed to analyse the effect of a single application of TiF(4) and NaF varnishes and solutions to protect against dentin erosion. Bovine root dentin samples were pre-treated with NaF-Duraphat varnish (2.26%F, pH 4.5), NaF/CaF(2)-Duofluorid varnish (5.63%F, pH 8.0), NaF-experimental varnish (2.45%F, pH 4.5), TiF(4)-experimental varnish (2.45%F, pH 1.2), NaF solution (2.26%F, pH 4.5), TiF(4) solution (2.45%F, pH 1.2) and placebo varnish (pH 5.0, no-F varnish control). Controls remained untreated. Ten samples in each group were then subjected to an erosive demineralisation (Sprite Zero, 4x 90s/day) and remineralisation (artificial saliva, between the erosive cycles) cycling for 5 days. Dentin loss was measured profilometrically after pre-treatment and after 1, 3 and 5 days of de-remineralisation cycling. The data were statistically analysed by two-way ANOVA and Bonferroni's post hoc test (p<0.05). After pre-treatment, TiF(4) solution significantly induced surface loss (1.08+/-0.53 microm). Only Duraphat reduced the dentin loss overtime, but it did not significantly differ from placebo varnish (at 3rd and 5th days) and TiF(4) varnish (at 3rd day). Duraphat varnish seems to be the best option to partially reduce dentin erosion. However, the maintenance of the effects of this treatment after successive erosive challenges is limited. Copyright 2009 Elsevier Ltd. All rights reserved.

Motivational interviewing to enhance treatment attendance in mental health settings: A systematic review and meta-analysis.

PubMed

Lawrence, P; Fulbrook, P; Somerset, S; Schulz, P

2017-11-01

WHAT IS KNOWN ON THE SUBJECT?: Despite differences between samples, some literature reviews have suggested that MI is effective in enhancing treatment attendance for individuals with mental health issues. Little is known regarding the effects of MI as a pre-treatment on individuals who are not seeking treatment for mental health issues. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: This systematic review of the literature and meta-analysis demonstrates that MI is most beneficial for individuals who are not seeking mental health treatment. MI represents an opportunity for health promotion when patients are unmotivated but may otherwise be amenable to an intervention. MI is effective as a pre-treatment intervention to motivate individuals to attend further post-MI treatment and counselling. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: MI is a process and a useful tool for clinicians in all therapeutic interactions, to motivate their patients to seek further assistance for mental heath issues. Health promotion and encouragement to attend further treatment sessions can be facilitated through telephone contact. Introduction The stages of change model suggests that individuals seeking treatment are in the "preparation" or the "action" stage of change, which is the desired outcome of successful Motivational Interviewing (MI) interventions. MI is known to enhance treatment attendance among individuals with mental health problems. Aim This study examined the published research on MI as a pre-treatment to enhance attendance among individuals treatment-seeking and non-treatment-seeking for mental health issues. Methods Fourteen randomized controlled trials were identified, and MI efficacy was examined dichotomously: attendance or non-attendance for post-MI therapy. Subgroup analysis investigated treatment-seeking and non-treatment-seeking groups. Results Despite wide variations in sample sizes, blinding and monitoring, intervention fidelity was absent in the majority of published studies. Meta-analysis revealed that MI pre-treatment improved attendance relative to comparison groups. Conclusions Individuals not seeking treatment for mental health issues benefited the most from MI. Despite differences in MI treatment intensity, short interventions were as effective as longer interventions, whereas two MI sessions for as little as 15 min were effective in enhancing treatment attendance. Implications for Practice Motivational interviewing is a useful tool for clinicians in all therapeutic interactions to help motivate patients to seek assistance for mental health issues. © 2017 John Wiley & Sons Ltd.

Effects of ultrasound and ultrasound assisted alkaline pretreatments on the enzymolysis and structural characteristics of rice protein.

PubMed

Li, Suyun; Yang, Xue; Zhang, Yanyan; Ma, Haile; Liang, Qiufang; Qu, Wenjuan; He, Ronghai; Zhou, Cunshan; Mahunu, Gustav Komla

2016-07-01

The objectives of this study were to investigate the effects of multi-frequency energy-gathered ultrasound (MFEGU) and MFEGU assisted alkaline pretreatments on the enzymolysis and the mechanism of two pretreatments accelerating the rice protein (RP) proteolysis process. The results showed that MFEGU and MFEGU assisted alkaline pretreatments improved significantly (P<0.05) the degree of hydrolysis (DH) and the protein elution amount of RP. Furthermore under the same DH conditions, ultrasound and ultrasound assisted alkaline pretreatments were more save the enzymolysis time than the unpretreatment. The changes in UV-vis spectra, fluorescence emission spectra indicated unfolding and destruction of RP by MFEGU and MFEGU assisted alkaline pretreatments. The circular dichroism analysis showed that both pretreatments decreased α-helix but increased β-sheet and random coil of RP. Amino acid composition revealed that MFEGU and MFEGU assisted alkaline pretreatments could increase the protein elution amount and the ratio of hydrophobic amino acids. Atomic force microscopy (AFM) indicated that both pretreatments destroyed the microstructures and reduced the particle size of RP. Therefore, MFEGU and MFEGU assisted alkaline pretreatments are beneficial to improving the degree of hydrolysis due to its sonochemistry effect on the molecular conformation as well as on the microstructure of protein. Copyright © 2015 Elsevier B.V. All rights reserved.

The Effect of Acid Pre-Treatment using Acetic Acid and Nitric Acid in The Production of Biogas from Rice Husk during Solid State Anaerobic Digestion (SS-AD)

NASA Astrophysics Data System (ADS)

Nugraha, Winardi Dwi; Syafrudin; Keumala, Cut Fadhila; Matin, Hasfi Hawali Abdul; Budiyono

2018-02-01

Pretreatment during biogas production aims to assist in degradation of lignin contained in the rice husk. In this study, pretreatment which is used are acid and biological pretreatment. Acid pretreatment was performed using acetic acid and nitric acid with a variety levels of 3% and 5%. While biological pretreatment as a control variable. Acid pretreatment was conducted by soaking the rice straw for 24 hours with acid variation. The study was conducted using Solid State Anaerobic Digestion (SS-AD) with 21% TS. Biogas production was measured using water displacement method every two days for 60 days at room temperature conditions. The results showed that acid pretreatment gave an effect on the production of biogas yield. The yield of the biogas produced by pretreatment of acetic acid of 5% and 3% was 43.28 and 45.86 ml/gr.TS. While the results without pretreatment biogas yield was 29.51 ml/gr.TS. The results yield biogas produced by pretreatment using nitric acid of 5% and 3% was 12.14 ml/gr.TS and 21.85 ml/gr.TS. Results biogas yield with acetic acid pretreatment was better than the biogas yield results with nitric acid pretreatment.

Insights into the effect of dilute acid, hot water or alkaline pretreatment on cellulose accessible surface area and the overall porosity of Populus

DOE PAGES

Meng, Xianzhi; Wells, Tyrone; Sun, Qining; ...

2015-06-19

Pretreatment is known to render biomass more reactive to cellulase by altering the chemical compositions as well as physical structures of biomass. Simons stain technique along with mercury porosimetry were applied on the acid, neutral, and alkaline pretreated materials to measure the accessible surface area of cellulose and pore size distribution of Populus. Results indicated that acid pretreatment is much more effective than water and alkaline pretreatment in terms of cellulose accessibility increase. Further investigation suggests that lignin does not dictate cellulose accessibility to the extent that hemicellulose does, but it does restrict xylan accessibility which in turn controls themore » access of cellulase to cellulose. The most interesting finding is that severe acid pretreatment significantly decreases the average pore size, i.e., 90% average size decrease could be observed after 60 min dilute acid pretreatment at 160 °C; moreover, the nano-pore space formed between coated microfibrils is increased after pretreatment, especially for the acid pretreatment, suggesting this particular type of biomass porosity is probably the most fundamental barrier to effective enzymatic hydrolysis.« less

Ethanol production from poplar wood through enzymatic saccharification and fermentation by dilute acid and SPORL pretreatments

Treesearch

Z.J. Wang; J.Y. Zhu; Ronald S. Jr. Zalesny; K.F. Chen

2012-05-01

Dilute acid (DA) and Sulfite Pretreatment to Overcome Recalcitrance of Lignocelluloses (SPORL) pretreatments were directly applied to wood chips of four poplar wood samples of different genotypes (hereafter referred to as poplars; Populus tremuloides Michx. ‘native aspen collection’; Populus deltoides Bartr. ex Marsh x Populus nigra L. ‘NE222’ and ‘DN5’; P. nigra x...

Platform construction and extraction mechanism study of magnetic mixed hemimicelles solid-phase extraction

PubMed Central

Xiao, Deli; Zhang, Chan; He, Jia; Zeng, Rong; Chen, Rong; He, Hua

2016-01-01

Simple, accurate and high-throughput pretreatment method would facilitate large-scale studies of trace analysis in complex samples. Magnetic mixed hemimicelles solid-phase extraction has the power to become a key pretreatment method in biological, environmental and clinical research. However, lacking of experimental predictability and unsharpness of extraction mechanism limit the development of this promising method. Herein, this work tries to establish theoretical-based experimental designs for extraction of trace analytes from complex samples using magnetic mixed hemimicelles solid-phase extraction. We selected three categories and six sub-types of compounds for systematic comparative study of extraction mechanism, and comprehensively illustrated the roles of different force (hydrophobic interaction, π-π stacking interactions, hydrogen-bonding interaction, electrostatic interaction) for the first time. What’s more, the application guidelines for supporting materials, surfactants and sample matrix were also summarized. The extraction mechanism and platform established in the study render its future promising for foreseeable and efficient pretreatment under theoretical based experimental design for trace analytes from environmental, biological and clinical samples. PMID:27924944

Bulk Cutting of Carbon Nanotubes Using Electron Beam Irradiation

NASA Technical Reports Server (NTRS)

Schmidt, Howard K. (Inventor); Hauge, Robert H. (Inventor); Smalley, Richard E. (Inventor); Rauwald, Urs (Inventor); Kittrell, W. Carter (Inventor); Ziegler, Kirk J. (Inventor); Gu, Zhenning (Inventor)

2013-01-01

According to some embodiments, the present invention provides a method for attaining short carbon nanotubes utilizing electron beam irradiation, for example, of a carbon nanotube sample. The sample may be pretreated, for example by oxonation. The pretreatment may introduce defects to the sidewalls of the nanotubes. The method is shown to produces nanotubes with a distribution of lengths, with the majority of lengths shorter than 100 tun. Further, the median length of the nanotubes is between about 20 nm and about 100 nm.

SEM/XPS analysis of fractured adhesively bonded graphite fibre-reinforced polyimide composites

NASA Technical Reports Server (NTRS)

Devilbiss, T. A.; Messick, D. L.; Wightman, J. P.; Progar, D. J.

1985-01-01

The surfaces of the graphite fiber-reinforced polyimide composites presently pretreated prior to bonding with polyimide adhesive contained variable amounts of a fluoropolymer, as determined by X-ray photoelectron spectroscopy. Lap shear strengths were determined for unaged samples and for those aged over 500- and 1000-hour periods at 177 and 232 C. Unaged sample lap strengths, which were the highest obtained, exhibited no variation with surface pretreatment, but a significant decrease is noted with increasing aging temperature. These thermally aged samples, however, had increased surface fluorine concentration, while a minimal concentration was found in unaged samples. SEM demonstrated a progressive shift from cohesive to adhesive failure for elevated temperature-aged composites.

Xylanase supplementation on enzymatic saccharification of dilute acid pretreated poplars at different severities

Treesearch

Chao Zhang; Xinshu Zhuang; Zhao Jiang Wang; Fred Matt; Franz St. John; J.Y. Zhu

2013-01-01

Three pairs of solid substrates from dilute acid pretreatment of two poplar wood samples were enzymatically hydrolyzed by cellulase preparations supplemented with xylanase. Supplementation of xylanase improved cellulose saccharification perhaps due to improved cellulose accessibility by xylan hydrolysis. Total xylan removal directly affected enzymatic cellulose...

Evaluation of Mediterranean Agricultural Residues as a Potential Feedstock for the Production of Biogas via Anaerobic Fermentation.

PubMed

Nitsos, Christos; Matsakas, Leonidas; Triantafyllidis, Kostas; Rova, Ulrika; Christakopoulos, Paul

2015-01-01

Hydrothermal, dilute acid, and steam explosion pretreatment methods, were evaluated for their efficiency to improve the methane production yield of three Mediterranean agricultural lignocellulosic residues such as olive tree pruning, grapevine pruning, and almond shells. Hydrothermal and dilute acid pretreatments provided low to moderate increase in the digestibility of the biomass samples, whereas steam explosion enabled the highest methane yields to be achieved for almond shells at 232.2 ± 13.0 mL CH4/gVS and olive pruning at 315.4 ± 0.0 mL CH4/gVS. Introduction of an enzymatic prehydrolysis step moderately improved methane yields for hydrothermal and dilute acid pretreated samples but not for the steam exploded ones.

Evaluation of Mediterranean Agricultural Residues as a Potential Feedstock for the Production of Biogas via Anaerobic Fermentation

PubMed Central

Nitsos, Christos; Triantafyllidis, Kostas

2015-01-01

Hydrothermal, dilute acid, and steam explosion pretreatment methods, were evaluated for their efficiency to improve the methane production yield of three Mediterranean agricultural lignocellulosic residues such as olive tree pruning, grapevine pruning, and almond shells. Hydrothermal and dilute acid pretreatments provided low to moderate increase in the digestibility of the biomass samples, whereas steam explosion enabled the highest methane yields to be achieved for almond shells at 232.2 ± 13.0 mL CH4/gVS and olive pruning at 315.4 ± 0.0 mL CH4/gVS. Introduction of an enzymatic prehydrolysis step moderately improved methane yields for hydrothermal and dilute acid pretreated samples but not for the steam exploded ones. PMID:26609521

Improving enzymatic hydrolysis of corn stover pretreated by ethylene glycol-perchloric acid-water mixture.

PubMed

He, Yu-Cai; Liu, Feng; Gong, Lei; Lu, Ting; Ding, Yun; Zhang, Dan-Ping; Qing, Qing; Zhang, Yue

2015-02-01

To improve the enzymatic saccharification of lignocellulosic biomass, a mixture of ethylene glycol-HClO4-water (88.8:1.2:10, w/w/w) was used for pretreating corn stover in this study. After the optimization in oil-bath system, the optimum pretreatment temperature and time were 130 °C and 30 min, respectively. After the saccharification of 10 g/L pretreated corn stover for 48 h, the saccharification rate was obtained in the yield of 77.4 %. To decrease pretreatment temperature and shorten pretreatment time, ethylene glycol-HClO4-water (88.8:1.2:10, w/w/w) media under microwave irradiation was employed to pretreat corn stover effectively at 100 °C and 200 W for 5 min. Finally, the recovered hydrolyzates containing glucose obtained from the enzymatic hydrolysis of pretreated corn stovers could be fermented into ethanol efficiently. These results would be helpful for developing a cost-effective pretreatment combined with enzymatic saccharification of cellulosic materials for the production of lignocellulosic ethanol.

Evaluation of ultrasound assisted potassium permanganate pre-treatment of spent coffee waste.

PubMed

Ravindran, Rajeev; Jaiswal, Swarna; Abu-Ghannam, Nissreen; Jaiswal, Amit K

2017-01-01

In the present study, novel pre-treatment for spent coffee waste (SCW) has been proposed which utilises the superior oxidising capacity of alkaline KMnO 4 assisted by ultra-sonication. The pre-treatment was conducted for different exposure times (10, 20, 30 and 40min) using different concentrations of KMnO 4 (1, 2, 3, 4, 5%w/v) at room temperature with solid/liquid ratio of 1:10. Pretreating SCW with 4% KMnO 4 and exposing it to ultrasound for 20min resulted in 98% cellulose recovery and a maximum lignin removal of 46%. 1.7 fold increase in reducing sugar yield was obtained after enzymatic hydrolysis of KMnO 4 pretreated SCW as compared to raw. SEM, XRD and FTIR analysis of the pretreated SCW revealed the various effects of pretreatment. Thermal behaviour of the pretreated substrate against the native biomass was also studied using DSC. Ultrasound-assisted potassium permanganate oxidation was found to be an effective pretreatment for SCW, and can be a used as a potential feedstock pretreatment strategy for bioethanol production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reversal of radiocontrast medium toxicity in human renal proximal tubular cells by white grape juice extract.

PubMed

Andreucci, Michele; Faga, Teresa; Pisani, Antonio; Sabbatini, Massimo; Russo, Domenico; Mattivi, Fulvio; De Sarro, Giovambattista; Navarra, Michele; Michael, Ashour

2015-03-05

Radiocontrast media (RCM)-induced nephrotoxicity (CIN) is a major clinical problem accounting for 12% of all hospital-acquired cases of acute kidney injury. The pathophysiology of CIN is not well understood, but direct toxic effects on renal cells have been postulated as contributing to CIN. We have investigated the effect of a white grape (Vitis vinifera) juice extract (WGJe) on human renal proximal tubular (HK-2) cells treated with the radiocontrast medium (RCM) sodium diatrizoate. WGJe caused an increase in phosphorylation of the prosurvival kinases Akt and ERK1/2 in HK-2 cells. Treatment of HK-2 cells with 75 mgI/ml sodium diatrizoate for 2.5h and then further incubation (for 27.5h) after removal of the RCM caused a drastic decrease in cell viability. However, pre-treatment with WGJe, prior to incubation with diatrizoate, dramatically improved cell viability. Analysis of key signaling molecules by Western blotting showed that diatrizoate caused a drastic decrease in phosphorylation of Akt (Ser473), FOXO1 (Thr24) and FOXO3a (Thr32) during the initial 2.5h incubation period, and WGJe pre-treatment caused a reversal of these effects. Further analysis by Western blotting of samples from HK-2 cells cultured for longer periods of time (for up to 27.5h after an initial 2.5h exposure to diatrizoate with or without WGJe pre-treatment) showed that WGJe pre-treatment caused a negative effect on phosphorylation of p38, NF-κB (Ser276) and pERK1/2 whilst having a positive effect on the phosphorylation of Akt, FOXO1/FOXO3a and maintained levels of Pim-1 kinase. WGJe may alleviate RCM toxicity through modulation of signaling molecules that are known to be involved in cell death and cell survival and its possible beneficial effects should be further investigated. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A combined pretreatment of 1,25-dihydroxyvitamin D3 and sodium valproate enhances the damaging effect of ionizing radiation on prostate cancer cells.

PubMed

Gavrilov, Vladimir; Leibovich, Yaron; Ariad, Samuel; Lavrenkov, Konstantin; Shany, Shraga

2010-07-01

Radiotherapy is one of the curative treatment options for prostate cancer (PCa). However, effective doses of ionizing radiation (IR) have a high risk of side effects. To increase sensitivity of PCa to IR we pretreated human androgen-refractory DU145 PCa cells with a combination of sodium valproate (VPA), a well-tolerated drug with histone deacetylases inhibiting activity, and 1,25-dihydroxyvitamin D3, 1,25(OH)2D3, the active metabolite of vitamin D, a well known anticancer agent. The results show that irradiation (4Gy) of DU145 PCa cells pretreated with a combination of 1 mM VPA and 100 nM 1,25(OH)2D3 efficiently suppressed (87.9%) PCa cell proliferation. IR after combined pretreatment resulted in increased DNA double-strand breaks expressed as levels of phosphorylated histone H2A.X, compared with non-treated cells the increase was 58.1% in pretreated cells and 11.8% in non-pretreated cells (p<0.002). Combined pretreatment enhanced IR-induced activation of DNA damage checkpoint kinase Chk2, 39.0% in pretreated cells compared to 23.8% in non-pretreated cells (p<0.05). These molecular changes led to DNA replication blockade, S-phase cell-cycle arrest and enhanced apoptosis. Cumulatively, the results indicate that combined pretreatment with VPA and 1,25(OH)2D3 followed by IR is a highly effective treatment for human PCa cells. This observation may have important implications for reducing doses of radiation administered to cancer patients thus limiting the severity of side effects. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Enhanced biomass delignification and enzymatic saccharification of canola straw by steam-explosion pretreatment.

PubMed

Garmakhany, Amir Daraei; Kashaninejad, Mahdi; Aalami, Mehran; Maghsoudlou, Yahya; Khomieri, Mortza; Tabil, Lope G

2014-06-01

In recent decades, bioconversion of lignocellulosic biomass to biofuel (ethanol and biodiesel) has been extensively investigated. The three main chemical constituents of biomass are cellulose, hemicellulose and lignin. Cellulose and hemicellulose are polysaccharides of primarily fermentable sugars, glucose and xylose respectively. Hemicellulose also includes small fermentable fractions of arabinose, galactose and mannose. The main issue in converting lignocellulosic biomass to fuel ethanol is the accessibility of the polysaccharides for enzymatic breakdown into monosaccharides. This study focused on the use of steam explosion as the pretreatment method for canola straw as lignocellulosic biomass. Result showed that steam explosion treatment of biomass increased cellulose accessibility and it hydrolysis by enzyme hydrolysis. Following 72 h of enzyme hydrolysis, a maximum cellulose conversion to glucose yield of 29.40% was obtained for the steam-exploded sample while the control showed 11.60% glucose yields. Steam explosion pretreatment increased glucose production and glucose yield by 200% and 153.22%, respectively, compared to the control sample. The crystalline index increased from 57.48% in untreated canola straw to 64.72% in steam-exploded samples. Steam explosion pretreatment of biomass increased cellulose accessibility, and enzymatic hydrolysis increased glucose production and glucose yield of canola straw. © 2013 Society of Chemical Industry.

Treatment of Neuropathic Pain with the Capsaicin 8% Patch: Is Pretreatment with Lidocaine Necessary?

PubMed Central

Kern, Kai-Uwe; Nowack, Walburga; Poole, Chris

2014-01-01

The capsaicin 8% patch can effectively treat neuropathic pain, but application can cause discomfort or a burning sensation. Until March 2013, it was recommended that patients be pretreated with a topical anesthetic, for example lidocaine, before capsaicin patch application. However, speculation existed over the need for pretreatment and its effectiveness in alleviating treatment-associated discomfort. This article compares tolerability to and efficacy of the capsaicin patch in pretreated and non-pretreated patients. All patients received a single capsaicin patch application. Pretreated patients received a lidocaine plaster before and intravenous lidocaine and metamizole infusions during capsaicin patch application. Pain levels, assessed using a Numeric Rating Scale (NRS), were used to determine tolerability and efficacy. All patients (pretreated n = 32; non-pretreated n = 26) completed 100% of the intended capsaicin patch application duration. At the time of capsaicin patch removal, 69% of pretreated and 88% of non-pretreated patients reported an NRS score increase, which returned to baseline by 6 hours post-treatment. There was no significant difference in mean NRS score between patient groups at any time during or after capsaicin patch treatment. Response was similar between patient groups; capsaicin patch treatment provided rapid and significant pain reductions that were sustained over 12 weeks. The same proportion of pretreated and non-pretreated patients reported willingness to receive retreatment with the capsaicin patch. This analysis shows that the capsaicin 8% patch is generally tolerable, and the small discomfort associated with patch application is short-lived. Lidocaine pretreatment does not have a significant effect on tolerability, efficacy, or patient willingness to receive retreatment. PMID:24289500

Phenolics and essential mineral profile of organic acid pretreated unripe banana flour.

PubMed

Anyasi, Tonna A; Jideani, Afam I O; Mchau, Godwin R A

2018-02-01

Banana fruit (Musa spp) though rich in essential minerals, has also been implicated for the presence of phytochemicals which nonetheless beneficial, can also act as mineral inhibitors when in forms such as phenolic compounds, phytates and tannins. This study assayed the essential macro and trace minerals as well as phenolic compounds present in unripe banana flour (UBF) obtained from the pulp of four different cultivars. Unripe banana flour was processed by oven drying in a forced air oven dryer at 70°C upon pretreatment with ascorbic, citric and lactic acid. Organic acid pretreatment was done separately on each unripe banana cultivar at concentrations of 10, 15 and 20g/L. Phenolic compounds were profiled using liquid chromatography mass spectrometry electrospray ion (LC-MS-ESI) while essential minerals were determined using inductively coupled plasma atomic emission spectroscopy (ICP-AES) and mass spectroscopy (ICP-MS) respectively. Results of LC-MS-ESI assay of phenolics revealed the presence of flavonoids: epicatechin and myricetin 3-O-rhamnosyl-glucoside in varying concentrations in UBF. Essential mineral profile indicated that Zinc had the least occurrence of 3.55mg/kg (p<0.05), while potassium was the most abundant mineral at 14746.73mg/kg in UBF of all four banana cultivars. Correlation between phenolic compounds and essential minerals using Pearson's Correlation Coefficient test revealed weak and inverse association between flavonoids and most macro and trace minerals present in UBF samples. Organic acid pretreatment thus exhibited little effect on phenolics and essential minerals of UBF samples, though, inhibitory influence of phenolic compounds was recorded on essential minerals. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Determination of trace nickel in hydrogenated cottonseed oil by electrothermal atomic absorption spectrometry after microwave-assisted digestion.

PubMed

Zhang, Gai

2012-01-01

Microwave digestion of hydrogenated cottonseed oil prior to trace nickel determination by electrothermal atomic absorption spectrometry (ETAAS) is proposed here for the first time. Currently, the methods outlined in U.S. Pharmacopeia 28 (USP28) or British Pharmacopeia (BP2003) are recommended as the official methods for analyzing nickel in hydrogenated cottonseed oil. With these methods the samples may be pre-treated by a silica or a platinum crucible. However, the samples were easily tarnished during sample pretreatment when using a silica crucible. In contrast, when using a platinum crucible, hydrogenated cottonseed oil acting as a reducing material may react with the platinum and destroy the crucible. The proposed microwave-assisted digestion avoided tarnishing of sample in the process of sample pretreatment and also reduced the cycle of analysis. The programs of microwave digestion and the parameters of ETAAS were optimized. The accuracy of the proposed method was investigated by analyzing real samples. The results were compared with the ones by pressurized-PTFE-bomb acid digestion and ones obtained by the U.S. Pharmacopeia 28 (USP28) method. The new method involves a relatively rapid matrix destruction technique compared with other present methods for the quantification of metals in oil. © 2011 Institute of Food Technologists®

Pre-treatment social anxiety severity moderates the impact of mindfulness-based stress reduction and aerobic exercise.

PubMed

Jazaieri, Hooria; Lee, Ihno A; Goldin, Philippe R; Gross, James J

2016-06-01

We examined whether social anxiety severity at pre-treatment would moderate the impact of mindfulness-based stress reduction (MBSR) or aerobic exercise (AE) for generalized social anxiety disorder. MBSR and AE produced equivalent reductions in weekly social anxiety symptoms. Improvements were moderated by pre-treatment social anxiety severity. Mindfulness-based stress reduction (MBSR) and aerobic exercise (AE) are effective in reducing symptoms of social anxiety. Pre-treatment social anxiety severity can be used to inform treatment recommendations. Both MBSR and AE produced equivalent reductions in weekly levels of social anxiety symptoms. MBSR appears to be most effective for patients with lower pre-treatment social anxiety symptom severity. AE appears to be most effective for patients with higher pre-treatment social anxiety symptom severity. © 2015 The British Psychological Society.

Combined (alkaline+ultrasonic) pretreatment effect on sewage sludge disintegration.

PubMed

Kim, Dong-Hoon; Jeong, Emma; Oh, Sae-Eun; Shin, Hang-Sik

2010-05-01

The individual effects of alkaline (pH 8-13) and ultrasonic (3750-45,000kJ/kg TS) pretreatments on the disintegration of sewage sludge were separately tested, and then the effect of combining these two methods at different intensity levels was investigated using response surface methodology (RSM). In the combined pretreatment, ultrasonic treatment was applied to the alkali-pretreated sludge. While the solubilization (SCOD/TCOD) increase was limited to 50% in individual pretreatments, it reached 70% in combined pretreatment, and the results clearly showed that preconditioning of sludge at high pH levels played a crucial role in enhancing the disintegration efficiency of the subsequent ultrasonic pretreatment. By applying regression analysis, the disintegration degree (DD) was fitted based on the actual value to a second order polynomial equation: Y=-172.44+29.82X(1)+5.30x10(-3)X(2)-7.53x10(-5)X(1)X(2)-1.10X(1)(2)-1.043x10(-7)X(2)(2), where X(1), X(2), and Y are pH, specific energy input (kJ/kg TS), and DD, respectively. In a 2D contour plot describing the tendency of DD with respect to pH and specific energy input, it was clear that DD increased as pH increased, but it seemed that DD decreased when the specific energy input exceeded about 20,000kJ/kg TS. This phenomenon tells us that there exists a certain point where additional energy input is ineffective in achieving further disintegration. A synergetic disintegration effect was also found in the combined pretreatment, with lower specific energy input in ultrasonic pretreatment yielding higher synergetic effect. Finally, in order to see the combined pretreatment effect in continuous operation, the sludge pretreated with low intensity alkaline (pH 9)/ultrasonic (7500kJ/kg TS) treatment was fed to a 3 L of anaerobic sequencing batch reactor after 70 days of control operation. CH(4) production yield significantly increased from 81.9+/-4.5mL CH(4)/g COD(added) to 127.3+/-5.0mL CH(4)/g COD(added) by pretreatment, and this enhanced performance was closely related to the solubilization increase of the sludge by pretreatment. However, enhanced anaerobic digestion resulted in 20% higher soluble N concentration in the reactor, which would be an additional burden in the subsequent nitrogen removal system.

The influence of different pretreatment methods on biogas production from Jatropha curcas oil cake.

PubMed

Jabłoński, Sławomir Jan; Kułażyński, Marek; Sikora, Ilona; Łukaszewicz, Marcin

2017-12-01

Drought and pest resistance, together with high oil content in its seeds, make Jatropha curcas a good oil source for biodiesel. Oil cake from J. curcas is not suitable for animal feeding and thus may be profitably used for additional energy production by conversion into biogas; however, the anaerobic digestion process must be optimized to obtain good efficiency. We subjected oil cake to thermal and acidic pretreatment to deactivate protease inhibitors and partially hydrolyze phytate. We then digested the samples in batch conditions to determine the effects of pretreatment on biogas production. Thermal pretreatment changed the kinetics of anaerobic digestion and reduced protease inhibitor activity and the concentration of phytate; however, biogas production efficiency was not affected (0.281 m 3  kg -1 ). To evaluate the possibility of recirculating water for SSF hydrolysis, ammonium nitrogen recovery from effluent was evaluated by its precipitation in the form of struvite (magnesium ammonium phosphate).Concentration of ammonium ions was reduced by 53% (to 980 mg L -1 ). We propose a water-saving concept based on percolation of J. curcas cake using anaerobic digestion effluent and feeding that percolate into a methanogenic bioreactor. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pretreatment of Lignocellulosic Wastes to Improve Ethanol and Biogas Production: A Review

PubMed Central

Taherzadeh, Mohammad J.; Karimi, Keikhosro

2008-01-01

Lignocelluloses are often a major or sometimes the sole components of different waste streams from various industries, forestry, agriculture and municipalities. Hydrolysis of these materials is the first step for either digestion to biogas (methane) or fermentation to ethanol. However, enzymatic hydrolysis of lignocelluloses with no pretreatment is usually not so effective because of high stability of the materials to enzymatic or bacterial attacks. The present work is dedicated to reviewing the methods that have been studied for pretreatment of lignocellulosic wastes for conversion to ethanol or biogas. Effective parameters in pretreatment of lignocelluloses, such as crystallinity, accessible surface area, and protection by lignin and hemicellulose are described first. Then, several pretreatment methods are discussed and their effects on improvement in ethanol and/or biogas production are described. They include milling, irradiation, microwave, steam explosion, ammonia fiber explosion (AFEX), supercritical CO2 and its explosion, alkaline hydrolysis, liquid hot-water pretreatment, organosolv processes, wet oxidation, ozonolysis, dilute-and concentrated-acid hydrolyses, and biological pretreatments. PMID:19325822

Application of Magnetic Nanoparticles in Pretreatment Device for POPs Analysis in Water

NASA Astrophysics Data System (ADS)

Chu, Dongzhi; Kong, Xiangfeng; Wu, Bingwei; Fan, Pingping; Cao, Xuan; Zhang, Ting

2018-01-01

In order to reduce process time and labour force of POPs pretreatment, and solve the problem that extraction column was easily clogged, the paper proposed a new technology of extraction and enrichment which used magnetic nanoparticles. Automatic pretreatment system had automatic sampling unit, extraction enrichment unit and elution enrichment unit. The paper briefly introduced the preparation technology of magnetic nanoparticles, and detailly introduced the structure and control system of automatic pretreatment system. The result of magnetic nanoparticles mass recovery experiments showed that the system had POPs analysis preprocessing capability, and the recovery rate of magnetic nanoparticles were over 70%. In conclusion, the author proposed three points optimization recommendation.

An advanced pretreatment strategy involving hydrodynamic and acoustic cavitation along with alum coagulation for the mineralization and biodegradability enhancement of tannery waste effluent.

PubMed

Saxena, Shivendu; Rajoriya, Sunil; Saharan, Virendra Kumar; George, Suja

2018-06-01

In the present study, coagulation followed by cavitation was studied as a pretreatment tool for tannery waste effluent (TWE) with the aim of reducing its COD, TOC, TSS etc. and enhancing its biodegradability to make it suitable for anaerobic digestion. Initially, coagulation was applied to TWE using alum as a coagulant. The residual pH of treated effluent was found to be around pH of 4.5 where maximum COD and TSS reduction was achieved. In order to enhance the efficiency of pretreatment process, coagulated tannery waste effluent (CTWE) was further subjected to hydrodynamic cavitation (HC) and ultrasonication (US). In case of HC, effect of process parameters such as inlet pressure and dilution on the treatment of CTWE was initially investigated. Lower operating pressure (5 bar) was more favorable for the treatment of CTWE using HC in order to enhance the biodegradability index (BI) from 0.14 to 0.57 in 120 min. The CTWE samples when subjected to 50% dilution, HC pretreatment exhibited higher percentage and quantum reduction in TOC and COD. On the other hand, pretreatment of TWE using coagulation followed by US demonstrated that BI of effluent was enhanced from 0.10 to 0.41 in 150 min. Energy efficiency evaluation for all processes at their optimized conditions was done based on the actual amount of COD reduced per unit energy delivered to the system. Coagulation followed by HC for the pretreatment of TWE was found to be six times more energy efficient as compared to coagulation followed by US. Copyright © 2018 Elsevier B.V. All rights reserved.

Effect of Varying Acid Hydrolysis Condition in Gracilaria Sp. Fermentation Using Sasad

NASA Astrophysics Data System (ADS)

Mansuit, H.; Samsuri, M. D. C.; Sipaut, C. S.; Yee, C. F.; Yasir, S. M.; Mansa, R.

2015-04-01

Macroalgae or seaweed is being considered as promising feedstock for bioalcohol production due to high polysaccharides content. Polysaccharides can be converted into fermentable sugar through acid hydrolysis pre-treatment. In this study, the potential of using carbohydrate-rich macroalgae, Gracilaria sp. as feedstock for bioalcohol production via various acid hydrolysis conditions prior to the fermentation process was investigated and evaluated. The seaweed used in this research was from the red algae group, using species of Gracilaria sp. which was collected from Sg. Petani Kedah, Malaysia. Pre-treatment of substrate was done using H2SO4 and HCl with molarity ranging from 0.2M to 0.8M. The pretreatment time were varied in the range of 15 to 30 minutes. Fermentation was conducted using Sasad, a local Sabahan fermentation agent as a starter culture. Alcohol extraction was done using a distillation unit. Reducing sugar analysis was done by Benedict test method. Alcohol content analysis was done using specific gravity test. After hydrolysis, it was found out that acid hydrolysis at 0.2M H2SO4 and pre-treated for 20 minutes at 121°C has shown the highest reducing sugar content which has yield (10.06 mg/g) of reducing sugar. It was followed by other samples hydrolysis using 0.4M HCl with 30 minutes pre-treatment and 0.2M H2SO4, 15 minutes pre-treatment with yield of 8.06 mg/g and 5.75 mg/g reducing sugar content respectively. In conclusion, acid hydrolysis of Gracilaria sp. can produce higher reducing sugar yield and thus it can further enhance the bioalcohol production yield. Hence, acid hydrolysis of Gracilaria sp. should be studied more as it is an important step in the bioalcohol production and upscaling process.

Comparison of Seven Chemical Pretreatments of Corn Straw for Improving Methane Yield by Anaerobic Digestion

PubMed Central

Song, Zilin; GaiheYang; Liu, Xiaofeng; Yan, Zhiying; Yuan, Yuexiang; Liao, Yinzhang

2014-01-01

Agriculture straw is considered a renewable resource that has the potential to contribute greatly to bioenergy supplies. Chemical pretreatment prior to anaerobic digestion can increase the anaerobic digestibility of agriculture straw. The present study investigated the effects of seven chemical pretreatments on the composition and methane yield of corn straw to assess their effectiveness of digestibility. Four acid reagents (H2SO4, HCl, H2O2, and CH3COOH) at concentrations of 1%, 2%, 3%, and 4% (w/w) and three alkaline reagents (NaOH, Ca(OH)2, and NH3·H2O) at concentrations of 4%, 6%, 8%, and 10% (w/w) were used for the pretreatments. All pretreatments were effective in the biodegradation of the lignocellulosic straw structure. The straw, pretreated with 3% H2O2 and 8% Ca(OH)2, acquired the highest methane yield of 216.7 and 206.6 mL CH4 g VS −1 in the acid and alkaline pretreatments, which are 115.4% and 105.3% greater than the untreated straw. H2O2 and Ca(OH)2 can be considered as the most favorable pretreatment methods for improving the methane yield of straw because of their effectiveness and low cost. PMID:24695485

Comparison of seven chemical pretreatments of corn straw for improving methane yield by anaerobic digestion.

PubMed

Song, Zilin; GaiheYang; Liu, Xiaofeng; Yan, Zhiying; Yuan, Yuexiang; Liao, Yinzhang

2014-01-01

Agriculture straw is considered a renewable resource that has the potential to contribute greatly to bioenergy supplies. Chemical pretreatment prior to anaerobic digestion can increase the anaerobic digestibility of agriculture straw. The present study investigated the effects of seven chemical pretreatments on the composition and methane yield of corn straw to assess their effectiveness of digestibility. Four acid reagents (H2SO4, HCl, H2O2, and CH3COOH) at concentrations of 1%, 2%, 3%, and 4% (w/w) and three alkaline reagents (NaOH, Ca(OH)2, and NH3·H2O) at concentrations of 4%, 6%, 8%, and 10% (w/w) were used for the pretreatments. All pretreatments were effective in the biodegradation of the lignocellulosic straw structure. The straw, pretreated with 3% H2O2 and 8% Ca(OH)2, acquired the highest methane yield of 216.7 and 206.6 mL CH4 g VS(-1) in the acid and alkaline pretreatments, which are 115.4% and 105.3% greater than the untreated straw. H2O2 and Ca(OH)2 can be considered as the most favorable pretreatment methods for improving the methane yield of straw because of their effectiveness and low cost.

Enhancement of phytochemical content and drying efficiency of onions (Allium cepa L.) through blanching.

PubMed

Ren, Feiyue; Perussello, Camila A; Zhang, Zhihang; Gaffney, Michael T; Kerry, Joseph P; Tiwari, Brijesh K

2018-03-01

This study investigated the effect of blanching (60, 70 and 80 °C for 1, 3, 5 and 10 min) combined with oven drying at 60 °C on the phenolic compounds, antioxidant activity, colour and drying characteristics (drying time, drying rate constant, effective moisture diffusivity and activation energy) of onion slices. Blanching of onion slices at 60 °C for 3 min and at 70 °C for 1 min prior to drying increased their bioactive compounds and antioxidant activity compared to the control samples and other treatments. Eighteen drying models were evaluated. The Modified Page and two-term exponential models best represented the drying data. The effective diffusivity ranged from 3.32 × 10 -11 m 2 s -1 (control) to 5.27 × 10 -11 m 2 s -1 , 5.01 × 10 -11 m 2 s -1 , and 4.74 × 10 -11 m 2 s -1 for onions blanched at 60 °C, 70 °C and 80 °C, respectively. The higher activation energy was observed for the control (unblanched) sample and slightly lower values were found for 1 min- and 3 min-blanched samples, confirming the higher drying efficiency as a result of the blanching pre-treatment. The use of blanching as a pre-treatment before drying of onions resulted in enhanced phytochemical content and drying efficiency. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Effects of grinding processes on enzymatic degradation of wheat straw.

PubMed

Silva, Gabriela Ghizzi D; Couturier, Marie; Berrin, Jean-Guy; Buléon, Alain; Rouau, Xavier

2012-01-01

The effectiveness of wheat straw fine to ultra-fine grindings at pilot scale was studied. The produced powders were characterised by their particle-size distribution (laser diffraction), crystallinity (WAXS) and enzymatic degradability (Trichoderma reesei enzymatic cocktail). A large range of wheat-straw powders was produced: from coarse (median particle size ∼800 μm) to fine particles (∼50 μm) using sieve-based grindings, then ultra-fine particles ∼20 μm by jet milling and ∼10 μm by ball milling. The wheat straw degradability was enhanced by the decrease of particle size until a limit: ∼100 μm, up to 36% total carbohydrate and 40% glucose hydrolysis yields. Ball milling samples overcame this limit up to 46% total carbohydrate and 72% glucose yields as a consequence of cellulose crystallinity reduction (from 22% to 13%). Ball milling appeared to be an effective pretreatment with similar glucose yield and superior carbohydrate yield compared to steam explosion pretreatment. Copyright © 2011 Elsevier Ltd. All rights reserved.

The effect of harvest time, dry matter content and mechanical pretreatments on anaerobic digestion and enzymatic hydrolysis of miscanthus.

PubMed

Frydendal-Nielsen, Susanne; Hjorth, Maibritt; Baby, Sanmohan; Felby, Claus; Jørgensen, Uffe; Gislum, René

2016-10-01

Miscanthus x giganteus was harvested as both green and mature biomass and the dry matter content of the driest harvest was artificially decreased by adding water in two subsamples, giving a total of five dry matter contents. All five biomass types were mechanically pretreated by roller-milling, extrusion or grinding and accumulated methane production and enzymatically-accessible sugars were measured. Accumulated methane production was studied using sigmoid curves that allowed comparison among the treatments of the rate of the methane production and ultimate methane yield. The green biomass gave the highest methane yield and highest levels of enzymatically-accessible cellulose. The driest biomass gave the best effect from extrusion but with the highest energy consumption, whereas roller-milling was most efficient on wet biomass. The addition of water to the last harvest improved the effect of roller-milling and equalled extrusion of the samples in efficiency. Copyright © 2016 Elsevier Ltd. All rights reserved.

Optimization of PMAxx pretreatment to distinguish between human norovirus with intact and altered capsids in shellfish and sewage samples.

PubMed

Randazzo, Walter; Khezri, Mohammad; Ollivier, Joanna; Le Guyader, Françoise S; Rodríguez-Díaz, Jesús; Aznar, Rosa; Sánchez, Gloria

2018-02-02

Shellfish contamination by human noroviruses (HuNoVs) is a serious health and economic problem. Recently an ISO procedure based on RT-qPCR for the quantitative detection of HuNoVs in shellfish has been issued, but these procedures cannot discriminate between inactivated and potentially infectious viruses. The aim of the present study was to optimize a pretreatment using PMAxx to better discriminate between intact and heat-treated HuNoVs in shellfish and sewage. To this end, the optimal conditions (30min incubation with 100μM of PMAxx and 0.5% of Triton, and double photoactivation) were applied to mussels, oysters and cockles artificially inoculated with thermally-inactivated (99°C for 5min) HuNoV GI and GII. This pretreatment reduced the signal of thermally-inactivated HuNoV GI in cockles and HuNoV GII in mussels by >3 log. Additionally, this pretreatment reduced the signal of thermally-inactivated HuNoV GI and GII between 1 and 1.5 log in oysters. Thermal inactivation of HuNoV GI and GII in PBS, sewage and bioaccumulated oysters was also evaluated by the PMAxx-Triton pretreatment. Results showed significant differences between reductions observed in the control and PMAxx-treated samples in PBS following treatment at 72 and 95°C for 15min. In sewage, the RT-qPCR signal of HuNoV GI was completely removed by the PMAxx pretreatment after heating at 72 and 95°C, while the RT-qPCR signal for HuNoV GII was completely eliminated only at 95°C. Finally, the PMAxx-Triton pretreatment was applied to naturally contaminated sewage and oysters, resulting in most of the HuNoV genomes quantified in sewage and oyster samples (12 out of 17) corresponding to undamaged capsids. Although this procedure may still overestimate infectivity, the PMAxx-Triton pretreatment represents a step forward to better interpret the quantification of intact HuNoVs in complex matrices, such as sewage and shellfish, and it could certainly be included in the procedures based on RT-qPCR. Copyright © 2017 Elsevier B.V. All rights reserved.

Extraction Methods in Soil Phosphorus Characterisation

NASA Astrophysics Data System (ADS)

Soinne, Helena

2010-05-01

Extraction methods are widely used to assess the bioavailability of P and to characterise soil P reserves. Even though new and more sophisticated methods to characterise soil P are constantly developed the use of extraction methods is not likely to be replaced because of the relatively simple analytical equipment needed for the analysis. However, the large variety of extractants, pre-treatments and sample preparation procedures complicate the comparison of published results. In order to improve our understanding of the behaviour and cycling of P in soil, it is important to know the role of extracted P in the soil P cycle. The knowledge of the factors affecting the analytical outcome is a prerequisite for justified interpretation of the results. In this study, the effect of sample pre-treatment and properties of the used extractant on extractable molybdate-reactive phosphorus (MRP) and molybdate-unreactive phosphorus (MUP) was studied. Furthermore, the effect of sample preparation procedures prior the analysis on measured MRP and MUP was studied. Two widely used sequential extraction procedures were compared on their ability to show management induced differences on soil P. These results revealed that pre-treatments changed soil properties and air-drying was found to affect soil P, particularly extractable MUP, thought to represent organic P, by disrupting organic matter. This was evidenced by an increase in the water-extractable small-sized (<0.2 µm) P that, at least partly, took place at the expense of the large-sized (>0.2 µm) P. In addition to the effects of sample pre-treatment, the results showed that extractable organic P was sensitive to the chemical nature of the used extractant and to the sample preparation procedures employed prior to P analysis, including centrifugation and filtering of soil suspensions. Filtering may remove a major proportion of extractable MUP; therefore filtering cannot be recommended in the characterisation of solubilised MUP. However, extractants having high ionic strength may cause the organic molecules to collapse during centrifugation and thus affect the recovered concentration of MUP. These findings highlight the importance of characterising the nature of the MUP extracted with different extractants and acknowledging the sensitivity of MUP to analytical procedures when comparing published results. Widely used sequential fractionation procedures proved to be able to detect land-use -derived differences in the distribution of P among fractions of different solubilities. The results of this study demonstrate that, although the extraction methods do not reveal the biogeochemical function of a given P pool in soil, the extraction methods can be used to detect changes in soil P pools with different solubilities. To obtain the most benefit from extraction methods, we need a better understanding of the biological availability of P and the role of extracted P fraction in the P cycle in soils from different environments (climatic and weather) and land-uses.

Effects of tretinoin pretreatment on TCA chemical peel in guinea pig skin.

PubMed Central

Kim, I. H.; Kim, H. K.; Kye, Y. C.

1996-01-01

This study was done to characterize the structural changes in the tretinoin pretreatment on trichloroacetic acid(TCA) chemical peel. In guinea pigs, the right halves pretreated with tretinoin and the left halves treated nothing were compared in their structural changes after TCA chemical peel. Epidermal thickness in the tretinoin pretreated group was almost the same in the first and second week. But epidermis of the TCA group increased continuously. In the first week, mitotic figures in the epidermis were more increased in the TCA group, but those in hair follicles were more increased in the tretinoin pretreated group. In the second week, mitotic figures in the epidermis were almost same in both group, but in hair follicles of the tretinoin pretreated group, mitotic figures were much more increased. In alcian blue staining, glycosaminoglycan was stained much more strongly in dermis of the TCA group in first week, but was more strongly stained in the tretinoin pretreated group in second week. On electron microscopic findings, the fibroblasts in upper dermis were larger and had plentier cytoplasm with more organelles in the tretinoin pretreated group. Conclusively, tretinoin pretreatment on TCA chemical peel sustained the effects of TCA longer and showed synergistic effects of TCA and induced enhanced wound healing. PMID:8878803

Enhanced mesophilic anaerobic digestion of food waste by thermal pretreatment: Substrate versus digestate heating.

PubMed

Ariunbaatar, Javkhlan; Panico, Antonio; Yeh, Daniel H; Pirozzi, Francesco; Lens, Piet N L; Esposito, Giovanni

2015-12-01

Food waste (FW) represents a source of high potential renewable energy if properly treated with anaerobic digestion (AD). Pretreating the substrates could yield a higher biomethane production in a shorter time. In this study, the effects of thermal (heating the FW in a separate chamber) and thermophilic (heating the full reactor content containing both FW and inoculum) pretreatments at 50, 60, 70 and 80°C prior to mesophilic AD were studied through a series of batch experiments. Pretreatments at a lower temperature (50°C) and a shorter time (<12h) had a positive effect on the AD process. The highest enhancement of the biomethane production with an increase by 44-46% was achieved with a thermophilic pretreatment at 50°C for 6-12h or a thermal pretreatment at 80°C for 1.5h. Thermophilic pretreatments at higher temperatures (>55°C) and longer operating times (>12h) yielded higher soluble chemical oxygen demand (CODs), but had a negative effect on the methanogenic activity. The thermal pretreatments at the same conditions resulted in a lower solubilization of COD. Based on net energy calculations, the enhanced biomethane production is sufficient to heat up the FW for the thermal, but not for the thermophilic pretreatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Improvements of the Vis-NIRS Model in the Prediction of Soil Organic Matter Content Using Spectral Pretreatments, Sample Selection, and Wavelength Optimization

NASA Astrophysics Data System (ADS)

Lin, Z. D.; Wang, Y. B.; Wang, R. J.; Wang, L. S.; Lu, C. P.; Zhang, Z. Y.; Song, L. T.; Liu, Y.

2017-07-01

A total of 130 topsoil samples collected from Guoyang County, Anhui Province, China, were used to establish a Vis-NIR model for the prediction of organic matter content (OMC) in lime concretion black soils. Different spectral pretreatments were applied for minimizing the irrelevant and useless information of the spectra and increasing the spectra correlation with the measured values. Subsequently, the Kennard-Stone (KS) method and sample set partitioning based on joint x-y distances (SPXY) were used to select the training set. Successive projection algorithm (SPA) and genetic algorithm (GA) were then applied for wavelength optimization. Finally, the principal component regression (PCR) model was constructed, in which the optimal number of principal components was determined using the leave-one-out cross validation technique. The results show that the combination of the Savitzky-Golay (SG) filter for smoothing and multiplicative scatter correction (MSC) can eliminate the effect of noise and baseline drift; the SPXY method is preferable to KS in the sample selection; both the SPA and the GA can significantly reduce the number of wavelength variables and favorably increase the accuracy, especially GA, which greatly improved the prediction accuracy of soil OMC with Rcc, RMSEP, and RPD up to 0.9316, 0.2142, and 2.3195, respectively.

Impact of cultivar selection and process optimization on ethanol yield from different varieties of sugarcane

PubMed Central

2014-01-01

Background The development of ‘energycane’ varieties of sugarcane is underway, targeting the use of both sugar juice and bagasse for ethanol production. The current study evaluated a selection of such ‘energycane’ cultivars for the combined ethanol yields from juice and bagasse, by optimization of dilute acid pretreatment optimization of bagasse for sugar yields. Method A central composite design under response surface methodology was used to investigate the effects of dilute acid pretreatment parameters followed by enzymatic hydrolysis on the combined sugar yield of bagasse samples. The pressed slurry generated from optimum pretreatment conditions (maximum combined sugar yield) was used as the substrate during batch and fed-batch simultaneous saccharification and fermentation (SSF) processes at different solid loadings and enzyme dosages, aiming to reach an ethanol concentration of at least 40 g/L. Results Significant variations were observed in sugar yields (xylose, glucose and combined sugar yield) from pretreatment-hydrolysis of bagasse from different cultivars of sugarcane. Up to 33% difference in combined sugar yield between best performing varieties and industrial bagasse was observed at optimal pretreatment-hydrolysis conditions. Significant improvement in overall ethanol yield after SSF of the pretreated bagasse was also observed from the best performing varieties (84.5 to 85.6%) compared to industrial bagasse (74.5%). The ethanol concentration showed inverse correlation with lignin content and the ratio of xylose to arabinose, but it showed positive correlation with glucose yield from pretreatment-hydrolysis. The overall assessment of the cultivars showed greater improvement in the final ethanol concentration (26.9 to 33.9%) and combined ethanol yields per hectare (83 to 94%) for the best performing varieties with respect to industrial sugarcane. Conclusions These results suggest that the selection of sugarcane variety to optimize ethanol production from bagasse can be achieved without adversely affecting juice ethanol and cane yield, thus maintaining first generation ethanol production levels while maximizing second generation ethanol production. PMID:24725458

The effect of porous lead iodide precursor film on perovskite film formation and its photovoltaic property after an effective pretreatment

NASA Astrophysics Data System (ADS)

Yan, Jian-Jun; Li, Yan; Chang, Yin; Jiang, Pan; Wang, Cheng-Wei

2016-06-01

An effective solvent sealed natural drying (SND) pretreatment was introduced for forming a satisfactory crystalline porous iodide (PbI2) precursor film, which could help to generate excellent CH3NH3PbI3 perovskite films for high performance of planar heterojunction perovskite solar cells. And the influence of SND pretreated time on the device performance was investigated in detail. We found that the PbI2 precursor film after 10 min pretreatment could make the perovskite device achieve the optimal power conversion efficiency (PCE) of 8.6%, significantly increased up to 95.5% and 28.4% compared to without pretreatment or traditional treatment. The results show that the time of SND pretreatment is critical to forming large grain size and good crystallinity for PbI2 precursor film, which would markedly improve the efficiency of planar heterojunction perovskite solar cells.

Pretreatment of Biomass by Aqueous Ammonia for Bioethanol Production

NASA Astrophysics Data System (ADS)

Kim, Tae Hyun; Gupta, Rajesh; Lee, Y. Y.

The methods of pretreatment of lignocellulosic biomass using aqueous ammonia are described. The main effect of ammonia treatment of biomass is delignification without significantly affecting the carbohydrate contents. It is a very effective pretreatment method especially for substrates that have low lignin contents such as agricultural residues and herbaceous feedstock. The ammonia-based pretreatment is well suited for simultaneous saccharification and co-fermentation (SSCF) because the treated biomass retains cellulose as well as hemicellulose. It has been demonstrated that overall ethanol yield above 75% of the theoretical maximum on the basis of total carbohydrate is achievable from corn stover pretreated with aqueous ammonia by way of SSCF. There are two different types of pretreatment methods based on aqueous ammonia: (1) high severity, low contact time process (ammonia recycle percolation; ARP), (2) low severity, high treatment time process (soaking in aqueous ammonia; SAA). Both of these methods are described and discussed for their features and effectiveness.

Facile synthesis of poly(ionic liquid)-bonded magnetic nanospheres as a high-performance sorbent for the pretreatment and determination of phenolic compounds in water samples.

PubMed

Bi, Wentao; Wang, Man; Yang, Xiaodi; Row, Kyung Ho

2014-07-01

Poly(ionic liquid)-bonded magnetic nanospheres were easily synthesized and applied to the pretreatment and determination of phenolic compounds in water samples, which have detrimental effects on water quality and the health of living beings. The high affinity of poly(ionic liquid)s toward the target compounds as well as the magnetic behavior of Fe3 O4 were combined in this material to provide an efficient and simple magnetic solid-phase extraction approach. The adsorption behavior of the poly(ionic liquid)-bonded magnetic nanospheres was examined to optimize the synthesis. Different parameters affecting the magnetic solid-phase extraction of phenolic compounds were assessed in terms of adsorption and recovery. Under the optimal conditions, the proposed method showed excellent detection sensitivity with limits of detection in the range of 0.3-0.8 ng/mL and precision in the range of 1.2-3.3%. This method was also applied successfully to the analysis of real water samples; good spiked recoveries over the range of 82.5-99.2% were obtained. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of andrographolide molecularly imprinted polymer for solid-phase extraction

NASA Astrophysics Data System (ADS)

Yin, Xiaoying; Liu, Qingshan; Jiang, Yifan; Luo, Yongming

2011-06-01

A method employing molecularly imprinted polymer (MIP) as selective sorbent for solid-phase extraction (SPE) to pretreat samples was developed. The polymers were prepared by precipitation polymerization with andrographolide as template molecule. The structure of MIP was characterized and its static adsorption capacity was measured by the Scatchard equation. In comparison with C 18-SPE and non-imprinted polymer (NIP) SPE column, MIP-SPE column displays high selectivity and good affinity for andrographolide and dehydroandrographolide for extract of herb Andrographis paniculata ( Burm.f.) Nees (APN). MIP-SPE column capacity was 11.9 ± 0.6 μmol/g and 12.1 ± 0.5 μmol/g for andrographolide and dehydroandrographolide, respectively and was 2-3 times higher than that of other two columns. The precision and accuracy of the method developed were satisfactory with recoveries between 96.4% and 103.8% (RSD 3.1-4.3%, n = 5) and 96.0% and 104.2% (RSD 2.9-3.7%, n = 5) for andrographolide and dehydroandrographolide, respectively. Various real samples were employed to confirm the feasibility of method. This developed method demonstrates the potential of molecularly imprinted solid phase extraction for rapid, selective, and effective sample pretreatment.

Interface chemistry and surface morphology evolution study for InAs/Al2O3 stacks upon in situ ultrahigh vacuum annealing

NASA Astrophysics Data System (ADS)

Wang, Xinglu; Qin, Xiaoye; Wang, Wen; Liu, Yue; Shi, Xiaoran; Sun, Yong; Liu, Chen; Zhao, Jiali; Zhang, Guanhua; Liu, Hui; Cho, Kyeongjae; Wu, Rui; Wang, Jiaou; Zhang, Sen; Wallace, Robert M.; Dong, Hong

2018-06-01

A systematic study of the interfacial chemistry for the HCl pretreated and native oxide InAs(100) samples upon atomic layer deposition (ALD) of Al2O3, and the post deposition annealing (PDA) process has been carried out, using in situ synchrotron radiation photoelectron spectroscopy. The "clean up" effect for the native oxide sample is detected, but it is not observed for the HCl pretreated sample. The out-diffusion and desorption of both In and As oxides have been characterized during the ALD process and the following PDA process. The surface morphology evolution during the PDA process is studied by in situ photo-emission electron microscopy. The bubbles emerged after PDA at 360 °C and grew up at 370 °C. After PDA at 400 °C and at higher temperatures, pits are seen in some areas, and the tear up of the Al2O3 film is seen in other areas with the formation of indium droplets. This study gives insight in the mechanism of elemental diffusion/desorption, which may associate the reliability of III-V semiconductor based devices.

Exposure and non-fear emotions: A randomized controlled study of exposure-based and rescripting-based imagery in PTSD treatment.

PubMed

Langkaas, Tomas Formo; Hoffart, Asle; Øktedalen, Tuva; Ulvenes, Pål G; Hembree, Elizabeth A; Smucker, Mervin

2017-10-01

Interventions involving rescripting-based imagery have been proposed as a better approach than exposure-based imagery when posttraumatic stress disorder (PTSD) is associated with emotions other than fear. Prior research led to the study's hypotheses that (a) higher pretreatment non-fear emotions would predict relatively better response to rescripting as compared to exposure, (b) rescripting would be associated with greater reduction in non-fear emotions, and (c) pretreatment non-fear emotions would predict poor response to exposure. A clinically representative sample of 65 patients presenting a wide range of traumas was recruited from patients seeking and being offered PTSD treatment in an inpatient setting. Subjects were randomly assigned to 10 weeks of treatment involving either rescripting-based imagery (Imagery Rescripting; IR) or exposure-based imagery (Prolonged Exposure; PE). Patients were assessed on outcome and emotion measures at pretreatment, posttreatment and 12 months follow-up. Comparison to control benchmarks indicated that both treatments were effective, but no outcome differences between them appeared. None of the initial hypotheses were supported. The results from this study challenge previous observations and hypotheses about exposure mainly being effective for fear-based PTSD and strengthen the notion that exposure-based treatment is a generally effective treatment for all types of PTSD. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Determination of Cu in Shell of Preserved Egg by LIBS Coupled with PLS].

PubMed

Hu, Hui-qin; Xu, Xue-hong; Liu, Mu-hua; Tu, Jian-ping; Huang, Le; Huang, Lin; Yao, Ming-yin; Chen, Tian-bing; Yang, Ping

2015-12-01

In this work, the content of copper in the shell of preserved eggs were determined directly by Laser induced breakdown spectroscopy (LIBS), and the characteristics lines of Cu was obtained. The samples of eggshell were pretreated by acid wet digestion, and the real content of Cu was obtained by atomic absorption spectrophotometer (AAS). Due to the test precision and accuracy of LIBS was influenced by a serious of factors, for example, the complex matrix effect of sample, the enviro nment noise, the system noise of the instrument, the stability of laser energy and so on. And the conventional unvariate linear calibration curve between LIBS intensity and content of element of sample, such as by use of Schiebe G-Lomakin equation, can not meet the requirement of quantitative analysis. In account of that, a kind of multivariate calibration method is needed. In this work, the data of LIBS spectra were processed by partial least squares (PLS), the precision and accuracy of PLS model were compared by different smoothing treatment and five pretreatment methods. The result showed that the correlation coefficient and the accuracy of the PLS model were improved, and the root mean square error and the average relative error were reduced effectively by 11 point smoothing with Multiplicative scatter correction (MSC) pretreatment. The results of the study show that, heavy metal Cu in preserved egg shells can be direct detected accurately by laser induced breakdown spectroscopy, and the next step batch tests will been conducted to find out the relationship of heavy metal Cu content in the preserved egg between the eggshell, egg white and egg yolk. And the goal of the contents of heavy metals in the egg white, egg yolk can be knew through determinate the eggshell by the LIBS can be achieved, to provide new method for rapid non-destructive testing technology for quality and satety of agricultural products.

Dielectric barrier discharge plasma pretreatment on hydrolysis of microcrystalline cellulose

NASA Astrophysics Data System (ADS)

Huang, Fangmin; Long, Zhouyang; Liu, Sa; Qin, Zhenglong

2017-04-01

Dielectric barrier discharge (DBD) plasma was used as a pretreatment method for downstream hydrolysis of microcrystalline cellulose (MCC). The degree of polymerization (DP) of MCC decreased after it was pretreated by DBD plasma under a carrier gas of air/argon. The effectiveness of depolymerization was found to be influenced by the crystallinity of MCC when under the pretreatment of DBD plasma. With the addition of tert-butyl alcohol in the treated MCC water suspension solution, depolymerization effectiveness of MCC was inhibited. When MCC was pretreated by DBD plasma for 30 min, the total reducing sugar concentration (TRSC) and liquefaction yield (LY) of pretreated-MCC (PMCC) increased by 82.98% and 34.18% respectively compared with those for raw MCC.

Direct Ethanol Production from Ionic Liquid-Pretreated Lignocellulosic Biomass by Cellulase-Displaying Yeasts.

PubMed

Yamada, Ryosuke; Nakashima, Kazunori; Asai-Nakashima, Nanami; Tokuhara, Wataru; Ishida, Nobuhiro; Katahira, Satoshi; Kamiya, Noriho; Ogino, Chiaki; Kondo, Akihiko

2017-05-01

Among the many types of lignocellulosic biomass pretreatment methods, the use of ionic liquids (ILs) is regarded as one of the most promising strategies. In this study, the effects of four kinds of ILs for pretreatment of lignocellulosic biomass such as bagasse, eucalyptus, and cedar were evaluated. In direct ethanol fermentation from biomass incorporated with ILs by cellulase-displaying yeast, 1-butyl-3-methylimidazolium acetate ([Bmim][OAc]) was the most effective IL. The ethanol production and yield from [Bmim][OAc]-pretreated bagasse reached 0.81 g/L and 73.4% of the theoretical yield after fermentation for 96 h. The results prove the initial concept, in which the direct fermentation from lignocellulosic biomass effectively promoted by the pretreatment with IL.

Pretreatment of Miscanthus stalk with organic alkali guanidine and amino-guanidine.

PubMed

Li, Wei; Wang, Wei; Xu, Piaopiao; Xu, Pingping; Zhao, Xiaoli; Wang, Yun

2015-03-01

Organic alkali guanidine and amino-guanidine were used as catalysts to pretreat Miscanthus stalks. The effects of catalyst loadings, pretreatment temperature and time, on pretreatment results were studied. Between guanidines and amino-guanidines, guanidines were of benefit to produce hexose and amino-guanidines were in favor of producing pentose in stalk enzymolysis process. SEM images showed that the stalk surface after pretreatment were porous, cracked, and corroded. XRD data showed that the relative crystallinity index of cellulose after pretreatment was increased. FTIR spectra illustrated that both guanidine and amino-guanidine were effective to remove lignin and degrade hydrogen bonds of cellulose. TG data indicated that the initial temperature of rapid weight loss of Miscanthus stalks pretreated by the guanidine was higher than that by the amino-guanidine. The maximum sugar yields of Miscanthus stalks pretreated by the guanidine and the amino-guanidine after enzymolysis for 24 h were 350 and 370 mg/g stalks, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

Physicochemical pretreatments and hydrolysis of furfural residues via carbon-based sulfonated solid acid.

PubMed

Ma, Bao Jun; Sun, Yuan; Lin, Ke Ying; Li, Bing; Liu, Wan Yi

2014-03-01

Potential commercial physicochemical pretreatment methods, NaOH/microwave and NaOH/ultrasound were developed, and the carbon-based sulfonated solid acid catalysts were prepared for furfural residues conversion into reducing sugars. After the two optimum pretreatments, both the content of cellulose increased (74.03%, 72.28%, respectively) and the content of hemicellulose (94.11%, 94.17% of removal rate, respectively) and lignin (91.75%, 92.09% of removal rate, respectively) decreased in furfural residues. The reducing sugar yields of furfural residues with the two physicochemical pretreatments on coal tar-based solid acid reached 33.94% and 33.13%, respectively, higher than that pretreated via NaOH alone (27%) and comparable to that pretreated via NaOH/H2O2 (35.67%). The XRD patterns, IR spectra and SEM images show microwave and ultrasound improve the pretreatment effect. The results demonstrate the carbon-based sulfonated solid acids and the physicochemical pretreatments are green, effective, low-cost for furfural residues conversion. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of various pretreatments on biological sulfate reduction with waste activated sludge as electron donor and waste activated sludge diminution under biosulfidogenic condition.

PubMed

Sheng, Yuxing; Cao, Hongbin; Li, Yuping; Zhang, Yi

2010-07-15

The current study focused on the influences of various pretreatments, including alkaline, ultrasonic and thermal pretreatments on biological sulfate reduction with waste activated sludge (WAS) as sole electron donor. Our results showed that thermal and ultrasonic pretreatments increased the sulfate reduction percentage by 14.8% and 7.1%, respectively, compared with experiment with raw WAS, while alkaline pretreatment decreased the sulfate reduction percentage by 46%. By analyzing the WAS structure, particle size distribution, organic component, and enzyme activity after different pretreatments, we studied the effects of these pretreatments on WAS as well as on the mechanisms of how biological sulfate reduction was affected. The reduction of WAS and variation of WAS structure in the process of sulfate reduction were investigated. Our results showed that biosulfidogenesis was an efficient method of diminishing WAS, and various pretreatments could enhance the reduction efficiency of volatile solid in the WAS. 2010 Elsevier B.V. All rights reserved.

[Effect of biological pretreatment with Trametes vesicolor on the enzymatic hydrolysis of softwood and hardwood].

PubMed

Yu, Hongbo; Zhang, Xiaoyu

2009-07-01

We evaluated the effect of biological pretreatment with white rot fungus Trametes vesicolor on the enzymatic hydrolysis of two wood species, Chinese willow (Salix babylonica, hardwood) and China-fir (Cunninghamia lanceolata, softwood). The result indicated that the pretreated woods showed significant increases in the final conversion ratios of enzymatic hydrolysis (4.78-fold for hardwood and 4.02-fold for softwood). In order to understand the role of biological pretreatment we investigated the enzyme-substrate interactions. Biological pretreatment enhanced the substrate accessibility to cellulase but not always correlated with the initial conversion rate. However, the change of the conversion rate decreased dramatically with increased desorption values after biological pretreatment. Thus, the biological pretreatment slowed down the declines in conversion rates during enzymatic hydrolysis by reducing the irreversible adsorption of cellulase and then improved the enzymatic hydrolysis. Moreover, the decreases of the irreversible adsorption may be attributed to the partial lignin degradation and alteration in lignin structure after biological pretreatment.

Pretreatment of Eucalyptus in biphasic system for furfural production and accelerated enzymatic hydrolysis.

PubMed

Zhang, Xiudong; Bai, Yuanyuan; Cao, Xuefei; Sun, Runcang

2017-08-01

Herein, an efficient biphasic pretreatment process was developed to improve the production of furfural (FF) and glucose from Eucalyptus. The influence of formic acid and NaCl on FF production from xylose in water and various biphasic systems was investigated. Results showed that the addition of formic acid and NaCl significantly promoted the FF yield, and the biphasic system of MIBK (methyl isobutyl ketone)/water exhibited the best performance for FF production. Then the Eucalyptus was pretreated in the MIBK/water system, and a maximum FF yield of 82.0% was achieved at 180°C for 60min. Surface of the pretreated Eucalyptus became relatively rough and loose, and its crystallinity index increased obviously due to the removal of hemicelluloses and lignin. The pretreated Eucalyptus samples showed much higher enzymatic hydrolysis rates (26.2-70.7%) than the raw Eucalyptus (14.5%). Copyright © 2017 Elsevier Ltd. All rights reserved.

Exploring crystalline-structural variations of cellulose during alkaline pretreatment for enhanced enzymatic hydrolysis.

PubMed

Ling, Zhe; Chen, Sheng; Zhang, Xun; Xu, Feng

2017-01-01

The study aimed to explore the crystallinity and crystalline structure of alkaline pretreated cellulose. The enzymatic hydrolysis followed by pretreatment was conducted for measuring the efficiency of sugar conversion. For cellulose Iβ dominated samples, alkaline pretreatment (<8wt%) caused increased cellulose crystallinity and depolymerized hemicelluloses, that were superimposed to affect the enzymatic conversion to glucose. Varying crystallite sizes and lattice spacings indicated the separation of cellulose crystals during mercerization (8-12wt% NaOH). Completion of mercerization was proved under higher alkaline concentration (14-18wt% NaOH), leading to distortion of crystalline cellulose to some extent. Cellulose II crystallinity showed a stimulative impact on enzymatic hydrolysis due to the weakened hydrophobic interactions within cellulose chains. The current study may provide innovative explanations for enhanced enzymatic digestibility of alkaline pretreated lignocellulosic materials. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dialysis Extraction for Chromatography

NASA Technical Reports Server (NTRS)

Jahnsen, V. J.

1985-01-01

Chromatographic-sample pretreatment by dialysis detects traces of organic contaminants in water samples analyzed in field with minimal analysis equipment and minimal quantities of solvent. Technique also of value wherever aqueous sample and solvent must not make direct contact.

Pyrolysis characteristics and kinetics of lignin derived from enzymatic hydrolysis residue of bamboo pretreated with white-rot fungus.

PubMed

Yan, Keliang; Liu, Fang; Chen, Qing; Ke, Ming; Huang, Xin; Hu, Weiyao; Zhou, Bo; Zhang, Xiaoyu; Yu, Hongbo

2016-01-01

The lignocellulose biorefinery based on the sugar platform usually focuses on polysaccharide bioconversion, while lignin is only burned for energy recovery. Pyrolysis can provide a novel route for the efficient utilization of residual lignin obtained from the enzymatic hydrolysis of lignocellulose. The pyrolysis characteristics of residual lignin are usually significantly affected by the pretreatment process because of structural alteration of lignin during pretreatment. In recent years, biological pretreatment using white-rot fungi has attracted extensive attention, but there are only few reports on thermal conversion of lignin derived from enzymatic hydrolysis residue (EHRL) of the bio-pretreated lignocellulose. Therefore, the study investigated the pyrolysis characteristics and kinetics of EHRL obtained from bamboo pretreated with Echinodontium taxodii in order to evaluate the potential of thermal conversion processes of EHRL. Fourier transform infrared spectroscopy spectra showed that EHRL of bamboo treated with E. taxodii had the typical lignin structure, but aromatic skeletal carbon and side chain of lignin were partially altered by the fungus. Thermogravimetric analysis indicated that EHRL pyrolysis at different heating rates could be divided into two depolymerization stages and covered a wide temperature range from 500 to 900 K. The thermal decomposition reaction can be well described by two third-order reactions. The kinetics study indicated that the EHRL of bamboo treated with white-rot fungus had lower apparent activation energies, lower peak temperatures of pyrolysis reaction, and higher char residue than the EHRL of raw bamboo. Pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) was applied to characterize the fast pyrolysis products of EHRL at 600 ℃. The ratios of guaiacyl-type to syringyl-type derivatives yield (G/S) and guaiacyl-type to p-hydroxy-phenylpropane-type derivatives yield (G/H) for the treated sample were increased by 33.18 and 25.30 % in comparison with the raw bamboo, respectively. The structural alterations of lignin during pretreatment can decrease the thermal stability of EHRL from the bio-treated bamboo and concentrate the guaiacyl-type derivatives in the fast pyrolysis products. Thus, the pyrolysis can be a promising route for effective utilization of the enzymatic hydrolysis residue from bio-pretreated lignocellulose.

The Synergistic Neuroprotective Effects of Combined Rosuvastatin and Resveratrol Pretreatment against Cerebral Ischemia/Reperfusion Injury.

PubMed

Liu, Ying; Yang, HongNa; Jia, GuoYong; Li, Lan; Chen, Hui; Bi, JianZhong; Wang, CuiLan

2018-06-01

It is well accepted that both rosuvastatin and resveratrol exert neuroprotective effects on cerebral ischemia/reperfusion injury through some common pathways. Resveratrol has also been demonstrated to protect against cerebral ischemia/reperfusion injury through enhancing autophagy. Thus, we hypothesized that combined rosuvastatin and resveratrol pretreatment had synergistic effects on cerebral ischemia/reperfusion injury. Adult male Sprague Dawley rats receiving middle cerebral artery occlusion surgery as animal model of cerebral ischemia/reperfusion injury were randomly assigned to 4 groups: control, resveratrol alone pretreatment, rosuvastatin alone pretreatment, and combined rosuvastatin and resveratrol pretreatment. Rosuvastatin (10 mg/kg) or resveratrol (50 mg/kg) was administrated once a day for 7 days before cerebral ischemia onset. We found that combined rosuvastatin and resveratrol pretreatment not only significantly decreased the neurologic defective score, cerebral infarct volume, the levels of caspase-3, and Interleukin-1β (IL-1β) but also significantly increased the ratios of Bcl-2/Bax and LC3II/LC3I, as well as the level of Becline-1, compared with resveratrol alone or rosuvastatin alone pretreatment group. Rosuvastatin alone pretreatment significantly increased the ratio of LC3II/LC3I and the level of Beclin-1. However, there were no significant differences in the neurologic defective score, cerebral infarct volume, the levels of caspase-3, IL-1β, and Beclin-1, and the ratios of Bcl-2/Bax and LC3II/LC3I between resveratrol pretreatment group and rosuvastatin pretreatment group. Synergistically enhanced antiapoptosis, anti-inflammation, and autophagy activation might be responsible for the synergistic neuroprotective effects of combining rosuvastatin with resveratrol on cerebral ischemia/reperfusion injury. Copyright © 2018 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Effect of chemo-mechanical disintegration on sludge anaerobic digestion for enhanced biogas production.

PubMed

Kavitha, S; Pray, S Saji; Yogalakshmi, K N; Kumar, S Adish; Yeom, Ick-Tae; Banu, J Rajesh

2016-02-01

The effect of combined surfactant-dispersion pretreatment on dairy waste activated sludge (WAS) reduction in anaerobic digesters was investigated. The experiments were performed with surfactant, Sodium dodecyl sulfate (SDS) in the range of 0.01 to 0.1 g/g suspended solids (SS) and disperser with rpm of 5000-25,000. The COD (chemical oxygen demand) solubilization, suspended solids reduction, and biogas generation increased for an energy input of 7377 kJ/kg total solids (TS) (12,000 rpm, 0.04 g/g SS, and 30 min) and were found to be 38, 32, and 75 %, higher than that of control. The pretreated sludge improved the performance of semicontinuous anaerobic digesters of 4 L working volume operated at four different SRTs (sludge retention time). SRT of 15 days was found to be appropriate showing 49 and 51 % reduction in SS and volatile solids (VS), respectively. The methane yield of the pretreated sample was observed to be 50 mL/g VS removed which was observed to be comparatively higher than the control (12 mL/g VS removed) at optimal SRT of 15 days. To the best of the authors' knowledge, this study is the first to be reported and not yet been documented in literature.

Effects of lignin structure on hydrodeoxygenation reactivity of pine wood lignin to valuable chemicals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Hongliang; Ben, Haoxi; Southeast Univ., Nanjing

Hydrodeoxygenation (HDO) of two dilute acid flow through pretreated softwood lignin samples, including residual lignin in pretreated solid residues (ReL) and recovered insoluble lignin in pretreated liquid (RISL), with apparent different physical and chemical structures, was comprehensively studied. A combination of catalysts (HY zeolite and Ru/Al 2O 3) was employed to investigate the effects of lignin structures, especially condensed structures, on the HDO upgrading process. Results indicated that the condensed structure and short side chains in lignin hindered its HDO conversion under different reaction conditions, including catalyst loading and composition, hydrogen pressure, and reaction time. In addition to lignin structure,more » HY zeolite was found crucial for lignin depolymerization, while Ru/Al 2O 3 and relatively high hydrogen pressure (4 MPa) were necessary for upgrading unstable oxy-compounds to cyclohexanes at high selectivity (>95 wt %). Since the lignin structure essentially affects its reactivity during HDO conversion, the yield and selectivity of HDO products can be predicted by detailed characterization of the lignin structure. Furthermore, the insights gained from this study in the fundamental reaction mechanisms based on the lignin structure will facilitate upgrading of lignin to high-value products for applications in the production of both fuels and chemicals.« less

Effects of lignin structure on hydrodeoxygenation reactivity of pine wood lignin to valuable chemicals

DOE PAGES

Wang, Hongliang; Ben, Haoxi; Southeast Univ., Nanjing; ...

2017-01-05

Hydrodeoxygenation (HDO) of two dilute acid flow through pretreated softwood lignin samples, including residual lignin in pretreated solid residues (ReL) and recovered insoluble lignin in pretreated liquid (RISL), with apparent different physical and chemical structures, was comprehensively studied. A combination of catalysts (HY zeolite and Ru/Al 2O 3) was employed to investigate the effects of lignin structures, especially condensed structures, on the HDO upgrading process. Results indicated that the condensed structure and short side chains in lignin hindered its HDO conversion under different reaction conditions, including catalyst loading and composition, hydrogen pressure, and reaction time. In addition to lignin structure,more » HY zeolite was found crucial for lignin depolymerization, while Ru/Al 2O 3 and relatively high hydrogen pressure (4 MPa) were necessary for upgrading unstable oxy-compounds to cyclohexanes at high selectivity (>95 wt %). Since the lignin structure essentially affects its reactivity during HDO conversion, the yield and selectivity of HDO products can be predicted by detailed characterization of the lignin structure. Furthermore, the insights gained from this study in the fundamental reaction mechanisms based on the lignin structure will facilitate upgrading of lignin to high-value products for applications in the production of both fuels and chemicals.« less

Long-term outcomes and predictors of internet-delivered cognitive behavioral therapy for childhood anxiety disorders.

PubMed

Vigerland, Sarah; Serlachius, Eva; Thulin, Ulrika; Andersson, Gerhard; Larsson, Jan-Olov; Ljótsson, Brjánn

2017-03-01

This study investigated the long-term outcomes of internet-delivered cognitive behavior therapy (ICBT) for children with anxiety disorders, and potential pre-treatment predictors of treatment outcome. The sample included eighty-four children (8-12 years old) with anxiety disorders, from both a treatment group and a waitlist control (after participants had crossed over to treatment) of a previous randomized controlled study. Participants were assessed at post-treatment and three- and twelve-months after treatment using a semi-structured interview and parent ratings. Pre-treatment data were used to investigate predictors of treatment outcome at three-month follow-up. Intention-to-treat analysis showed that treatment gains were maintained at twelve-month follow-up, including clinician rated severity of the principal anxiety disorder, parent rated anxiety symptoms and global functioning, with mainly large effect sizes (Cohen's d = 0.63-2.35). Completer analyses showed that suspected autism spectrum disorder was associated with less change in symptom severity. No other pre-treatment measures significantly predicted treatment outcome. This study suggests that internet-delivered CBT can have long-term beneficial effects for children with anxiety disorders. Predictors of treatment outcome need to be evaluated further. Clinicaltrials.gov; NCT01533402. Copyright © 2016 Elsevier Ltd. All rights reserved.

Prognostic significance of pretreatment neutrophil-to-lymphocyte ratio in melanoma patients: A meta-analysis.

PubMed

Zhan, Hui; Ma, Jian-Ying; Jian, Qi-Chao

2018-05-29

Recently, the prognostic value of the neutrophil-to-lymphocyte ratio (NLR) has been widely evaluated in many cancers. Here we assessed the prognostic value of pretreatment NLR in melanoma. A range of online databases was systematically searched up to March,2018 for identify available studies which assessed the prognostic significance of NLR. Data from studies reporting a hazard ratio (HR) and 95% confidence interval (CI) were weighted by generic inverse-variance and pooled in random effects meta-analysis. Twelve studies with 4593 individuals were included. Patients with elevated NLR had a significantly shorter overall survival (OS) (HR: 1.56, 95% CI: 1.28-1.90, p < .001) and disease-free survival (DFS)/progression-free survival (PFS) (HR = 1.86; 95% CI = 1.24-2.80; P = .003). Subgroup analyses showed that the negative prognostic effect of elevated NLR on OS remained substantial in North American and Europen populations and patients with non-metastatic and metastatic stage. Additionally, elevated NLR was related to worse OS in patients with melanoma, regardless of the sample size and the cut-off value. Our findings suggest that elevated pretreatment NLR was associated with poor prognosis in melanoma patients, suggesting NLR might be a prognostic factor in patients with melanoma. Copyright © 2018 Elsevier B.V. All rights reserved.

Furnishing spaceship environment: evaluation of bacterial biofilms on different materials used inside International Space Station.

PubMed

Perrin, Elena; Bacci, Giovanni; Garrelly, Laurent; Canganella, Francesco; Bianconi, Giovanna; Fani, Renato; Mengoni, Alessio

2018-05-08

Performed inside International Space Station (ISS) from 2011 to 2016, VIABLE (eValuatIon And monitoring of microBiofiLms insidE International Space Station) ISS was a long-lasting experiment aimed at evaluating the bacterial contamination on different surface space materials subjected to different pre-treatment, to provide useful information for future space missions. In this work, surfaces samples of the VIABLE ISS experiment were analyzed to determine both the total bacterial load (ATP-metry, qPCR) and the composition of the microbial communities (16S rRNA genes amplicon sequencing). Data obtained showed a low bacterial contamination of all the surfaces, with values in agreement with those allowed inside ISS, and with a taxonomic composition similar to those found in previous studies (Enterobacteriales, Bacillales, Lactobacillales and Actinomycetales). No pre-treatment or material effect were observed on both the bacterial load and the composition of the communities, but for both a slight effect of the position (expose/not expose to air) was observed. In conclusion, under the conditions used for VIABLE ISS, no material or pre-treatment seems to be better than others in terms of quantity and type of bacterial contamination. Copyright © 2018 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Effect of Chemical Washing Pre-treatment of Empty Fruit Bunch (EFB) biochar on Characterization of Hydrogel Biochar composite as Bioadsorbent

NASA Astrophysics Data System (ADS)

Meri, N. H.; Alias, A. B.; Talib, N.; Rashid, Z. A.; Wan, W. A.; Ghani, Ab Karim

2018-05-01

Hydrogel biochar composite (HBC) is a recent interest among researchers because of the hydrophilic characteristic which can adsorb chemical fluid and showed a versatile potential as adsorbent in removing hazardous material in wastewater and gas stream. In this study, the effect of chemical washing pre-treatment by using two different type of chemical agent Hydrochloric Acid (HCL) and Hydrogen Peroxide (H2O2) was analysed and investigated. The raw EFB biochar was prepared using microwave assisted pyrolysis under 1000W for 30 min under N2 flow with 150 mL/min. To improve the adsoprtion ability, the EFB biochar has been chemical washed pre-treatment with Hydrochloric Acid (HCl) and Hydrogen Peroxide (H2O2) before polymerization process with acrylamide (AAm) as monomer, N,N’-methylenebisacrylamide (MBA) as crosslinker and ammonium persulfate (APS) as initiator. The characterization has studied by using Fourier transform infrared spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC). FTIR result shows that, the formation of Raw EFB to Hydrogel Biochar Composite (Raw EFB > EFB Biochar > Treated Biochars (HCl & H2O2) > Hydrogel Biochar Composite) have changed in functional group. For DSC result it shows that the thermal behaviour of all samples is endothermic process and have high thermal resistance.

Benefits from Tween during enzymic hydrolysis of corn stover

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaar, W.E.; Holtzapple, M.T.

1998-08-20

Corn stover is a potential substrate for fermentation processes. Previous work with corn stover demonstrated that lime pretreatment rendered it digestible by cellulase; however, high sugar yields required very high enzyme loadings. Because cellulase is a significant cost in biomass conversion processes, the present study focused on improving the enzyme efficiency using Tween 20 and Tween 80; Tween 20 is slightly more effective than Tween 80. The recommended pretreatment conditions for the biomass remained unchanged regardless of whether Tween was added during the hydrolysis. The recommended Tween loading was 0.15 g Tween/g dry biomass. The critical relationship was the Tweenmore » loading on the biomass, not the Tween concentration in solution. The 72-h enzymic conversion of pretreated corn stover using 5 FPU cellulase/g dry biomass at 50 C with Tween 20 as part of the medium was 0.85 g/g for cellulose, 0.66 g/g for xylan, and 0.75 for total polysaccharide; addition of Tween improved the cellulose, xylan, and total polysaccharide conversions by 42, 40, and 42%, respectively. Kinetic analyses showed that Tween improved the enzymic absorption constants, which increased the effective hydrolysis rate compared to hydrolysis without Tween. Furthermore, Tween prevented thermal deactivation of the enzymes, which allows for the kinetic advantage of higher temperature hydrolysis. Ultimate digestion studies showed higher conversions for samples containing Tween, indicating a substrate effect. It appears that Tween improves corn stover hydrolysis through three effects: enzyme stabilizer, lignocellulose disrupter, and enzyme effector.« less

Alkaline peroxide pretreatment of corn stover: effects of biomass, peroxide, and enzyme loading and composition on yields of glucose and xylose

PubMed Central

2011-01-01

Background Pretreatment is a critical step in the conversion of lignocellulose to fermentable sugars. Although many pretreatment processes are currently under investigation, none of them are entirely satisfactory in regard to effectiveness, cost, or environmental impact. The use of hydrogen peroxide at pH 11.5 (alkaline hydrogen peroxide (AHP)) was shown by Gould and coworkers to be an effective pretreatment of grass stovers and other plant materials in the context of animal nutrition and ethanol production. Our earlier experiments indicated that AHP performed well when compared against two other alkaline pretreatments. Here, we explored several key parameters to test the potential of AHP for further improvement relevant to lignocellulosic ethanol production. Results The effects of biomass loading, hydrogen peroxide loading, residence time, and pH control were tested in combination with subsequent digestion with a commercial enzyme preparation, optimized mixtures of four commercial enzymes, or optimized synthetic mixtures of pure enzymes. AHP pretreatment was performed at room temperature (23°C) and atmospheric pressure, and after AHP pretreatment the biomass was neutralized with HCl but not washed before enzyme digestion. Standard enzyme digestion conditions were 0.2% glucan loading, 15 mg protein/g glucan, and 48 h digestion at 50°C. Higher pretreatment biomass loadings (10% to 20%) gave higher monomeric glucose (Glc) and xylose (Xyl) yields than the 2% loading used in earlier studies. An H2O2 loading of 0.25 g/g biomass was almost as effective as 0.5 g/g, but 0.125 g/g was significantly less effective. Optimized mixtures of four commercial enzymes substantially increased post-AHP-pretreatment enzymatic hydrolysis yields at all H2O2 concentrations compared to any single commercial enzyme. At a pretreatment biomass loading of 10% and an H2O2 loading of 0.5 g/g biomass, an optimized commercial mixture at total protein loadings of 8 or 15 mg/g glucan gave monomeric Glc yields of 83% or 95%, respectively. Yields of Glc and Xyl after pretreatment at a low hydrogen peroxide loading (0.125 g H2O2/g biomass) could be improved by extending the pretreatment residence time to 48 h and readjusting the pH to 11.5 every 6 h during the pretreatment. A Glc yield of 77% was obtained using a pretreatment of 15% biomass loading, 0.125 g H2O2/g biomass, and 48 h with pH adjustment, followed by digestion with an optimized commercial enzyme mixture at an enzyme loading of 15 mg protein/g glucan. Conclusions Alkaline peroxide is an effective pretreatment for corn stover. Particular advantages are the use of reagents with low environmental impact and avoidance of special reaction chambers. Reasonable yields of monomeric Glc can be obtained at an H2O2 concentration one-quarter of that used in previous AHP research. Additional improvements in the AHP process, such as peroxide stabilization, peroxide recycling, and improved pH control, could lead to further improvements in AHP pretreatment. PMID:21658263

Anaerobic fermentation of biogas liquid pretreated maize straw by rumen microorganisms in vitro.

PubMed

Jin, Wenyao; Xu, Xiaochen; Gao, Yang; Yang, Fenglin; Wang, Gang

2014-02-01

This study intended to investigate the effect of pretreatment of maize straw with biogas liquid on followed fermentation by rumen microorganisms in vitro. The multiple effects including treated time, temperature and dosage of biogas liquid in pretreatment on the followed fermentation performance were analyzed by orthogonal array. The optimum conditions of pretreatment were 9days, 25°C and 50% (v/w) dosage of biogas liquid, which were indicated by the corresponding crystallinity index, dry matter digestibility (DMD) and acetate limiting-step concentration were 57.5%, 73.76% and 1756mg/L, respectively. The ordering sequence of the influential factors for pretreatment was treated time > temperature > dosage of biogas liquid. The results of fermentation showed that the maize straw pretreated by biogas liquid was an efficient and economic pretreatment method of maize straw. Copyright © 2013 Elsevier Ltd. All rights reserved.

Air radon equilibrium factor measurement in a Waste Water Pre-Treatment Plant

NASA Astrophysics Data System (ADS)

Martinez, J. E.; Juste, B.; Ortiz, J.; Martorell, S.; Verdu, G.

2017-11-01

We analyze in this paper a Waste Water Pre-Treatment Plant (WWTP) located at the Mediterranean coast with air radon concentration above Spanish action level (600 Bq per cubic meter). This paper presents a method for radon equilibrium determination by gamma spectrometry measuring of the radon progeny concentrations in the air, in order to estimate WWTP workers effective dose more exactly. The method is based on simultaneous sampling of air through a filter paper and alpha spectrometry measurement of radon activity concentration in the air. According to the measured radon activity concentration in the air of 368±45 Bq/m3 the equilibrium factor between radon and progenies is estimated to be F=0.27, which is in good agreement with expected values.

Investigating Mass Transport Limitations on Xylan Hydrolysis During Dilute Acid Pretreatment of Poplar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mittal, Ashutosh; Pilath, Heid M.; Parent, Yves

2014-04-28

Mass transport limitations could be an impediment to achieving high sugar yields during biomass pretreatment and thus be a critical factor in the economics of biofuels production. The objective of this work was to study the mass transfer restrictions imposed by the structure of biomass on the hydrolysis of xylan during dilute acid pretreatment of biomass. Mass transfer effects were studied by pretreating poplar wood at particle sizes ranging from 10 micrometers to 10 mm. This work showed a significant reduction in the rate of xylan hydrolysis in poplar when compared to the intrinsic rate of hydrolysis for isolated xylanmore » that is possible in the absence of mass transfer. In poplar samples we observed no significant difference in the rates of xylan hydrolysis over more than two orders of magnitude in particle size. It appears that no additional mass transport restrictions are introduced by increasing particle size from 10 micrometers to 10 mm. This work suggests that the rates of xylan hydrolysis in biomass particles are limited primarily by the diffusion of hydrolysis products out of plant cell walls. A mathematical description is presented to describe the kinetics of xylan hydrolysis that includes transport of the hydrolysis products through biomass into the bulk solution. The modeling results show that the effective diffusion coefficient of the hydrolysis products in the cell wall is several orders of magnitude smaller than typical values in other applications signifying the role of plant cell walls in offering resistance to diffusion of the hydrolysis products.« less

The Effect of Pretreatment with Thiopental on Reducing Pain Induced by Rocuronium Injection

PubMed Central

Park, Jong-Taek; Choi, Jae-Chan; Yoo, Young-Soo; Lee, Young-Bok; Kim, Soon-Yul

2005-01-01

We examined whether pretreatment with a small dose of thiopental was effective in reducing pain induced by the intravenous injection of rocuronium. Withdrawal movement was used to assess pain reduction. Ninety patients were randomly assigned to one of two groups: patients in the control group were pretreated with 2 mL saline, and those in the thiopental group were pretreated with 2 mL (50 mg) thiopental. Thiopental 5 mg/kg was injected intravenously. After a loss of consciousness, the upper arm was compressed with a rubber tourniquet, and the pretreatment drugs were administered. Thirty seconds later the tourniquet was removed and 0.6 mg/kg rocuronium was administered. Withdrawal movement was assessed using a four-grade scale: no movement, movement limited to the wrist, to the elbow or to the shoulder. The frequency of withdrawal movement in the group pretreated with thiopental was lower than in the control group (34 vs. 13, p < 0.05). We concluded that pretreatment with 2 mL (50 mg) thiopental is effective in reducing pain caused by the intravenous injection of rocuronium. PMID:16385651

Effect of L-Cysteine Pretreatment on the Control of Formaldehyde and Browning of the Culinary-Medicinal Shiitake Mushroom, Lentinus edodes (Higher Basidiomycetes) during Drying and Canning Processes.

PubMed

Li, Guijie; Wang, Qiang; Sun, Peng; Chen, Feng; Chen, Xiaolin; Wang, Cun; Zhao, Xin

2015-01-01

Fresh culinary-medicinal Shiitake mushrooms (Lentinus edodes) were pretreated by soaking in 0.1 mg/mL of L-cysteine solution for 1 hour; then the variation in formaldehyde content and browning degree were studied during hot air-drying and canning processes. The results indicated that L-cysteine pretreatment significantly inhibited the increase of formaldehyde content and browning during the drying process; these increases in the pretreatment groups ranged from 7.0% to 14.0% and 65.4% to 68.9%, respectively, of that of the control groups. While the L-cysteine pretreatment did not seem to have a significant effect on controlling the formaldehyde content during the canning process, the increase of the browning degree of the canned products of the pretreatment groups ranged from 64.8% to 78.5% of that of the control groups, indicating the inhibitive effect of L-cysteine on browning during the canning process of L. edodes. Overall, L-cysteine pretreatment improved the sensory quality of both dried and canned L. edodes.

Multi-scale processes of beech wood disintegration and pretreatment with 1-ethyl-3-methylimidazolium acetate/water mixtures.

PubMed

Viell, Jörn; Inouye, Hideyo; Szekely, Noemi K; Frielinghaus, Henrich; Marks, Caroline; Wang, Yumei; Anders, Nico; Spiess, Antje C; Makowski, Lee

2016-01-01

The valorization of biomass for chemicals and fuels requires efficient pretreatment. One effective strategy involves the pretreatment with ionic liquids which enables enzymatic saccharification of wood within a few hours under mild conditions. This pretreatment strategy is, however, limited by water and the ionic liquids are rather expensive. The scarce understanding of the involved effects, however, challenges the design of alternative pretreatment concepts. This work investigates the multi length-scale effects of pretreatment of wood in 1-ethyl-3-methylimidazolium acetate (EMIMAc) in mixtures with water using spectroscopy, X-ray and neutron scattering. The structure of beech wood is disintegrated in EMIMAc/water mixtures with a water content up to 8.6 wt%. Above 10.7 wt%, the pretreated wood is not disintegrated, but still much better digested enzymatically compared to native wood. In both regimes, component analysis of the solid after pretreatment shows an extraction of few percent of lignin and hemicellulose. In concentrated EMIMAc, xylan is extracted more efficiently and lignin is defunctionalized. Corresponding to the disintegration at macroscopic scale, SANS and XRD show isotropy and a loss of crystallinity in the pretreated wood, but without distinct reflections of type II cellulose. Hence, the microfibril assembly is decrystallized into rather amorphous cellulose within the cell wall. The molecular and structural changes elucidate the processes of wood pretreatment in EMIMAc/water mixtures. In the aqueous regime with >10.7 wt% water in EMIMAc, xyloglucan and lignin moieties are extracted, which leads to coalescence of fibrillary cellulose structures. Dilute EMIMAc/water mixtures thus resemble established aqueous pretreatment concepts. In concentrated EMIMAc, the swelling due to decrystallinization of cellulose, dissolution of cross-linking xylan, and defunctionalization of lignin releases the mechanical stress to result in macroscopic disintegration of cells. The remaining cell wall constituents of lignin and hemicellulose, however, limit a recrystallization of the solvated cellulose. These pretreatment mechanisms are beyond common pretreatment concepts and pave the way for a formulation of mechanistic requirements of pretreatment with simpler pretreatment liquors.

[Research of the surface oxide film on anodizing Ni-Cr porcelain alloy].

PubMed

Zhu, Song; Sun, Hong-Chen; Zhang, Jing-Wei; Li, Zong-Hui

2006-08-01

To study the shape, thickness and oxide percentage of major metal element of oxide film on Ni-Cr porcelain alloy after anodizing pretreatment. 10 samples were made and divided into 2 groups at random. Then after surface pretreatment, the oxide films of two samples of each group were analyzed using electronic scanning microscope. The rest 3 samples were measured by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). Lightly selective solution appeared because the different component parts of the alloy have dissimilar electrode, whose dissolve velocity were quite unlike. The sample's metal surface expanded, so the mechanical interlocking of porcelain and metal increased bond strength. The thickness of oxide film was 1.72 times of the control samples. The oxide percentage of major metal elements such as Cr, Ni and Mo were higher, especially Cr. It initially involved the formation of a thin oxide bound to the alloy and second, the ability of the formed oxide to saturate the porcelain, completing the chemical bond of porcelain to metal. The method of anodizing Ni-Cr porcelain alloy can easily control the forming of oxide film which was thin and its surface pattern was uniform. It is repeated and a good method of surface pretreatment before firing cycle.

Thermal Pretreatment of Wood for Co-gasification/co-firing of Biomass and Coal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Ping; Howard, Bret; Hedges, Sheila

2013-10-29

Utilization of biomass as a co-feed in coal and biomass co-firing and co-gasification requires size reduction of the biomass. Reducing biomass to below 0.2 mm without pretreatment is difficult and costly because biomass is fibrous and compressible. Torrefaction is a promising thermal pretreatment process and has the advantages of increasing energy density, improving grindability, producing fuels with more homogenous compositions and hydrophobic behavior. Temperature is the most important factor for the torrefaction process. Biomass grindability is related to cell wall structure, thickness and composition. Thermal treatment such as torrefaction can cause chemical changes that significantly affect the strength of biomass.more » The objectives of this study are to understand the mechanism by which torrefaction improves the grindability of biomass and discuss suitable temperatures for thermal pretreatment for co-gasification/co-firing of biomass and coal. Wild cherry wood was selected as the model for this study. Samples were prepared by sawing a single tangential section from the heartwood and cutting it into eleven pieces. The samples were consecutively heated at 220, 260, 300, 350, 450 and 550⁰C for 0.5 hr under flowing nitrogen in a tube furnace. Untreated and treated samples were characterized for physical properties (color, dimensions and weight), microstructural changes by SEM, and cell wall composition changes and thermal behaviors by TGA and DSC. The morphology of the wood remained intact through the treatment range but the cell walls were thinner. Thermal treatments were observed to decompose the cell wall components. Hemicellulose decomposed over the range of ~200 to 300⁰C and resulted in weakening of the cell walls and subsequently improved grindability. Furthermore, wood samples treated above 300⁰C lost more than 39% in mass. Therefore, thermal pretreatment above the hemicelluloses decomposition temperature but below 300⁰C is probably sufficient to improve grindability and retain energy value.« less

Analytical Approaches to Understanding the Role of Non-carbohydrate Components in Wood Biorefinery

NASA Astrophysics Data System (ADS)

Leskinen, Timo Ensio

This dissertation describes the production and analysis of wood subjected to a novel electron beam-steam explosion pretreatment (EB-SE) pretreatment with the aim to evaluate its suitability for the production of bioethanol. The goal of these studies was to: 1) develop analytical methods for the investigation of depolymerization of wood components under pretreatments, 2) analyze the effects of EB-SE pretreatment on the pretreated biomass, 3) define how lignin and extractive components affect the action of enzymes on cellulosic substrates, and 4) examine how changes in lignin structure impact its isolation and potential conversion into value added chemicals. The first section of the work describes the development of a size-exclusion chromatography (SEC) methodology for molecular weight analysis for native and pretreated wood. The selective analysis of carbohydrates and lignin from native wood was made possible by the combination of two selective derivatization methods, ionic liquid assisted benzoylation of the carbohydrate fraction and acetobromination of the lignin in acetic acid media. This method was then used to examine changes in softwood samples after the EB-SE pretreatment. The methodology was shown to be effective for monitoring changes in the molecular weight profiles of the pretreated wood. The second section of the work investigates synergistic effects of the EB-SE pretreatment on the molecular level structures of wood components and the significance of these alterations in terms of enzymatic digestibility. The two pretreatment steps depolymerized cell wall components in different fashion, while showing synergistic effects. Hardwood and softwood species responded differently to similar treatment conditions, which was attributed to the well-known differences in the structure of their lignin and hemicellulose fractions. The relatively crosslinked lignin in softwood appeared to limit swelling and subsequent depolymerization in comparison to hardwood. Additional studies revealed that an insoluble, likely crosslinked, lignin fraction induced enzyme inhibition, while soluble lower molecular weight fractions were slightly beneficial for the enzymatic hydrolysis of cellulose. The third section of the work addresses the influence of hydrophobic wood extractives and representative model compounds on the cellulolytic hydrolysis of cellulosic substrates. Deposition of specific fractions of isolated wood extractives on cellulose was found either to enhance or inhibit the action of cellulase enzymes, depending on the chemical nature of the fraction. Using model compounds this effect was found to be correlated with the compounds chemical structure, and underlying mechanisms could be rationalized by Hansen solubility parameter considerations. The amphiphilic and hydrophobic nature of the model extractives was found to influence the deposition of extractives on the cellulose surfaces, and the adsorption of cellulolytic enzymes, as measured with Quartz Crystal Microgravimetry. Beneficial effects of the extractives were likely related to reduction in the irreversible binding of the enzymes on the cellulose substrate. The fourth section of the work deals with the recovery of lignin using extraction methods based on aqueous alkali or aqueous ethanol. The objective of this study was to understand how the yield, MW and structure of lignin recovered from the process residue was impacted by the different isolation methods. Mild extraction conditions allowed for recovery of approximately 40 wt.% of the lignin present in the process residues. Base or acid catalyzed hydrolysis of the lignin could increase the recovery lignin yield to about 76 wt.%. The recovered lignins were characterized in terms of their functional groups, molecular weights and thermal properties. The lignins from mild alkali and ethanol extractions showed similarities in their chemical profiles while, as expected, the hydrolyzed lignins were different and depended on the hydrolysis conditions. The molecular weight and thermal properties of the lignin products were affected by the applied isolation process.

Pretreatment effects on orange processing waste for making ethanol by simultaneous saccharification and fermentation

USDA-ARS?s Scientific Manuscript database

Pretreatment of orange processing waste (CPW) by steam explosion under various conditions (pretreatment time, pH and temperatures) was investigated. Pretreatments longer than 4 min with steam purging resulted in CPW containing less than 0.1% limonene, an inhibitor for fermentation. Steam pretreatmen...

Microneedle pretreatment enhances the percutaneous permeation of hydrophilic compounds with high melting points

PubMed Central

2012-01-01

Background Two commercially available microneedle rollers with a needle length of 200 μm and 300 μm were selected to examine the influence of microneedle pretreatment on the percutaneous permeation of four non-steroidal anti-inflammatory drugs (diclofenac, ibuprofen, ketoprofen, paracetamol) with different physicochemical drug characteristics in Franz-type diffusion cells. Samples of the receptor fluids were taken at predefined times over 6 hours and were analysed by UV–VIS high-performance liquid-chromatography. Histological examinations after methylene blue application were additionally performed to gather information about barrier disruption. Results Despite no visible pores in the stratum corneum, the microneedle pretreatment resulted in a twofold (200 μm) and threefold higher (300 μm) flux through the pretreated skin samples compared to untreated skin samples for ibuprofen and ketoprofen (LogKow > 3, melting point < 100°C). The flux of the hydrophilic compounds diclofenac and paracetamol (logKow < 1, melting point > 100°C) increased their amount by four (200 μm) to eight (300 μm), respectively. Conclusion Commercially available microneedle rollers with 200–300 μm long needles enhance the drug delivery of topically applied non-steroidal anti-inflammatory drugs and represent a valuable tool for percutaneous permeation enhancement particularly for substances with poor permeability due to a hydrophilic nature and high melting points. PMID:22947102

SU-E-T-148: Benchmarks and Pre-Treatment Reviews: A Study of Quality Assurance Effectiveness

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lowenstein, J; Nguyen, H; Roll, J

Purpose: To determine the impact benchmarks and pre-treatment reviews have on improving the quality of submitted clinical trial data. Methods: Benchmarks are used to evaluate a site’s ability to develop a treatment that meets a specific protocol’s treatment guidelines prior to placing their first patient on the protocol. A pre-treatment review is an actual patient placed on the protocol in which the dosimetry and contour volumes are evaluated to be per protocol guidelines prior to allowing the beginning of the treatment. A key component of these QA mechanisms is that sites are provided timely feedback to educate them on howmore » to plan per the protocol and prevent protocol deviations on patients accrued to a protocol. For both benchmarks and pre-treatment reviews a dose volume analysis (DVA) was performed using MIM softwareTM. For pre-treatment reviews a volume contour evaluation was also performed. Results: IROC Houston performed a QA effectiveness analysis of a protocol which required both benchmarks and pre-treatment reviews. In 70 percent of the patient cases submitted, the benchmark played an effective role in assuring that the pre-treatment review of the cases met protocol requirements. The 35 percent of sites failing the benchmark subsequently modified there planning technique to pass the benchmark before being allowed to submit a patient for pre-treatment review. However, in 30 percent of the submitted cases the pre-treatment review failed where the majority (71 percent) failed the DVA. 20 percent of sites submitting patients failed to correct their dose volume discrepancies indicated by the benchmark case. Conclusion: Benchmark cases and pre-treatment reviews can be an effective QA tool to educate sites on protocol guidelines and to minimize deviations. Without the benchmark cases it is possible that 65 percent of the cases undergoing a pre-treatment review would have failed to meet the protocols requirements.Support: U24-CA-180803.« less

Effect of hydrogen peroxide pretreatment on the structural features and the enzymatic hydrolysis of rice straw.

PubMed

Wei, C J; Cheng, C Y

1985-10-01

Assessment was made to evaluate the effect of hydrogen peroxide pretreatment on the change of the structural features and the enzymatic hydrolysis of rice straw. Changes in the lignin content, weight loss, accessibility for Cadoxen, water holding capacity, and crystallinity of straw were measured during pretreatment to express the modification of the lignocellulosic structure of straw. The rates and the extents of enzymatic hydrolysis, cellulase adsorption, and cellobiose accumulation in the initial stage of hydrolysis were determined to study the pretreatment effect on hydrolysis. Pretreatment at 60 degrees C for 5 h in a solution with 1% (w/w) H(2)O(2) and NaOH resulted in 60% delignification, 40% weight loss, a fivefold increase in the accessibility for Cadoxen, an one times increase in the water-holding capacity, and only a slight decrease in crystallinity as compared with that of the untreated straw. Improvement on the pretreatment effect could be made by increasing the initial alkalinity and the pretreatment temperature of hydrogen peroxide solution. A saturated improvement on the structural features was found when the weight ratio of hydrogen peroxide to straw was above 0.25 g H(2)O(2)/g straw in an alkaline H(2)O(2) solution with 1% (w/w) NaOH at 32 degrees C. The initial rates and extents of hydrolysis, cellulase adsorption, and cellobiose accumulation in hydrolysis were enhanced in accordance with the improved structural features of straw pretreated. A four times increase in the extent of the enzymatic hydrolysis of straw for 24 h was attributed to the alkaline hydrogen peroxide pretreatment.

Bio-char from treated and untreated oil palm fronds

NASA Astrophysics Data System (ADS)

Sulaiman, Fauziah; Abdullah, Nurhayati; Rahman, Aizuddin Abdul

2013-05-01

The palm oil industry generates almost 94% of biomass in Malaysia, while other agricultural and forestry by-products contribute the remaining of 6%. Oil palm fronds (OPF) are estimated to be the highest available biomass amounting to 44.84 million tonnes in Malaysia. However, studies on OPF for thermochemical conversion technology which has good potential for energy conversion are still lacking. In this work, pyrolysis of OPF is conducted by using a fixed bed reactor. Samples were carbonized at slow pyrolysis temperature of around 300 to 500°C with heating rate of 10°C min-1. In addition, samples were treated for 20 min with distilled water at ambient temperature to reduce the ash content. Effectiveness of pre-treatment can be determined by observing the percentage of ash content reduction of each sample after undergoing washing pre-treatment. At 300°C, the char yields of the untreated OPF were slightly higher at 50.95% compared to the treated sample at 49.77%. Approximately all bio-char from the treated samples have better high heating value (HHV) of around 18-20 MJ kg-1 compared to the untreated samples. Besides that, all treated OPF char is more carbon rich and considered to be environmental friendly due to its low nitrogen content compared to the untreated OPF char. In this work, microscopic analysis of OPF bio-char were also studied by observing and evaluating their structure surface and morphology.

Effect of surface pretreatment of TiO2 films on interfacial processes leading to bacterial inactivation in the dark and under light irradiation

PubMed Central

Rtimi, Sami; Nesic, Jelena; Pulgarin, Cesar; Sanjines, Rosendo; Bensimon, Michael; Kiwi, John

2015-01-01

Evidence is presented for radio-frequency plasma pretreatment enhancing the amount and adhesion of TiO2 sputtered on polyester (PES) and on polyethylene (PE) films. Pretreatment is necessary to attain a suitable TiO2 loading leading to an acceptable Escherichia coli reduction kinetics in the dark or under light irradiation for PES–TiO2 and PE–TiO2 samples. The amount of TiO2 on the films was monitored by diffuse reflectance spectroscopy and X-ray fluorescence. X-ray electron spectroscopy shows the lack of accumulation of bacterial residues such as C, N and S during bacterial inactivation since they seem to be rapidly destroyed by TiO2 photocatalysis. Evidence was found for Ti4+/Ti3+ redox catalysis occurring on PES–TiO2 and PE–TiO2 during the bacterial inactivation process. On PE–TiO2 surfaces, Fourier transform infrared spectroscopy (ATR-FTIR) provides evidence for a systematic shift of the na(CH2) stretching vibrations preceding bacterial inactivation within 60 min. The discontinuous IR-peak shifts reflect the increase in the C–H inter-bond distance leading to bond scission. The mechanism leading to E. coli loss of viability on PES–TiO2 was investigated in the dark up to complete bacterial inactivation by monitoring the damage in the bacterial outer cell by transmission electron microscopy. After 30 min, the critical step during the E. coli inactivation commences for dark disinfection on 0.1–5% wt PES–TiO2 samples. The interactions between the TiO2 aggregates and the outer lipopolysaccharide cell wall involve electrostatic effects competing with the van der Waals forces. PMID:25657831

Effect of surface pretreatment of TiO2 films on interfacial processes leading to bacterial inactivation in the dark and under light irradiation.

PubMed

Rtimi, Sami; Nesic, Jelena; Pulgarin, Cesar; Sanjines, Rosendo; Bensimon, Michael; Kiwi, John

2015-02-06

Evidence is presented for radio-frequency plasma pretreatment enhancing the amount and adhesion of TiO2 sputtered on polyester (PES) and on polyethylene (PE) films. Pretreatment is necessary to attain a suitable TiO2 loading leading to an acceptable Escherichia coli reduction kinetics in the dark or under light irradiation for PES-TiO2 and PE-TiO2 samples. The amount of TiO2 on the films was monitored by diffuse reflectance spectroscopy and X-ray fluorescence. X-ray electron spectroscopy shows the lack of accumulation of bacterial residues such as C, N and S during bacterial inactivation since they seem to be rapidly destroyed by TiO2 photocatalysis. Evidence was found for Ti(4+)/Ti(3+) redox catalysis occurring on PES-TiO2 and PE-TiO2 during the bacterial inactivation process. On PE-TiO2 surfaces, Fourier transform infrared spectroscopy (ATR-FTIR) provides evidence for a systematic shift of the na(CH2) stretching vibrations preceding bacterial inactivation within 60 min. The discontinuous IR-peak shifts reflect the increase in the C-H inter-bond distance leading to bond scission. The mechanism leading to E. coli loss of viability on PES-TiO2 was investigated in the dark up to complete bacterial inactivation by monitoring the damage in the bacterial outer cell by transmission electron microscopy. After 30 min, the critical step during the E. coli inactivation commences for dark disinfection on 0.1-5% wt PES-TiO2 samples. The interactions between the TiO2 aggregates and the outer lipopolysaccharide cell wall involve electrostatic effects competing with the van der Waals forces.

Rapid fingerprinting and classification of extra virgin olive oil by microjet sampling and extractive electrospray ionization mass spectrometry.

PubMed

Law, Wai Siang; Chen, Huan Wen; Balabin, Roman; Berchtold, Christian; Meier, Lukas; Zenobi, Renato

2010-04-01

Microjet sampling in combination with extractive electrospray ionization (EESI) mass spectrometry (MS) was applied to the rapid characterization and classification of extra virgin olive oil (EVOO) without any sample pretreatment. When modifying the composition of the primary ESI spray solvent, mass spectra of an identical EVOO sample showed differences. This demonstrates the capability of this technique to extract molecules with varying polarities, hence generating rich molecular information of the EVOO. Moreover, with the aid of microjet sampling, compounds of different volatilities (e.g.E-2-hexenal, trans-trans-2,4-heptadienal, tyrosol and caffeic acid) could be sampled simultaneously. EVOO data was also compared with that of other edible oils. Principal Component Analysis (PCA) was performed to discriminate EVOO and EVOO adulterated with edible oils. Microjet sampling EESI-MS was found to be a simple, rapid (less than 2 min analysis time per sample) and powerful method to obtain MS fingerprints of EVOO without requiring any complicated sample pretreatment steps.

Procedure for rapid determination of δ15N and δ18O values of nitrate: development and application to an irrigated rice paddy watershed.

PubMed

Yada, Saeko; Nakajima, Yasuhiro; Itahashi, Sunao; Asada, Kei; Yoshikawa, Seiko; Eguchi, Sadao

2016-01-01

The dual isotope approach using the stable isotope ratios of nitrate nitrogen (δ(15)N(NO3)) and oxygen (δ(18)O(NO3)) is a strong tool for identifying the history of nitrate in various environments. Basically, a rapid procedure for determining δ(15)N(NO3) and δ(18)O(NO3) values is required to analyze many more samples quickly and thus save on the operational costs of isotope-ratio mass spectrometry (IRMS). We developed a new rapid procedure to save time by pre-treating consecutive samples of nitrous oxide microbially converted from nitrate before IRMS determination. By controlling two six-port valves of the pre-treatment system separately, IRMS determination of the current sample and backflush during the next sample pre-treatment period could be conducted simultaneously. A set of 89 samples was analyzed precisely during a 25-h continuous run (17 min per sample), giving the fastest reported processing time, and simultaneously reducing liquid nitrogen and carrier helium gas consumption by 35%. Application of the procedure to an irrigated rice paddy watershed suggested that nitrate concentrations in river waters decreased in a downstream direction, mainly because of the mixing of nitrate from different sources, without distinct evidence of denitrification. Our procedure should help with more detailed studies of nitrate formation processes in watersheds.

Effect of Mucuna pruriens Seed Extract Pretreatment on the Responses of Spontaneously Beating Rat Atria and Aortic Ring to Naja sputatrix (Javan Spitting Cobra) Venom

PubMed Central

Fung, Shin Yee; Tan, Nget Hong; Sim, Si Mui; Aguiyi, John C.

2012-01-01

Mucuna pruriens Linn. (velvet bean) has been used by native Nigerians as a prophylactic for snakebite. Rats pretreated with M. pruriens seed extract (MPE) have been shown to protect against the lethal and cardiovascular depressant effects of Naja sputatrix (Javan spitting cobra) venoms, and the protective effect involved immunological neutralization of the venom toxins. To investigate further the mechanism of the protective effect of MPE pretreatment against cobra venom toxicity, the actions of Naja sputatrix venom on spontaneously beating rat atria and aortic rings isolated from both MPE pretreated and untreated rats were studied. Our results showed that the MPE pretreatment conferred protection against cobra venom-induced depression of atrial contractility and atrial rate in the isolated atrial preparations, but it had no effect on the venom-induced contractile response of aortic ring preparation. These observations suggested that the protective effect of MPE pretreatment against cobra venom toxicity involves a direct protective action of MPE on the heart function, in addition to the known immunological neutralization mechanism, and that the protective effect does not involve action on blood vessel contraction. The results also suggest that M. pruriens seed may contain novel cardioprotective agent with potential therapeutic value. PMID:21785646

Interaction Between Short-Term Heat Pretreatment and Avermectin On 2nd Instar Larvae of Diamondback Moth, Plutella Xylostella (Linn)

PubMed Central

Gu, Xiaojun; Tian, Sufen; Wang, Dehui; Gao, Fei

2009-01-01

Based on the cooperative virulence index (c.f.), the interaction effect between short-term heat pretreatment and avermectin on 2nd instar larvae of diamondback moth (DBM), Plutella xylostella (Linnaeus), was assessed. The results suggested that the interaction results between short-term heat pretreatment and avermectin on the tested insects varied with temperature level as well as its duration and avermectin concentration. Interaction between heat pretreatment at 30°C and avermectin mainly resulted in addition. Meanwhile, pretreatment at 35°C for 2 or 4 h could antagonize the toxicity of avermectin at lower concentrations, which indicated a hormetic effect occurred. The results indicate that cooperative virulence index (c.f.) may be adopted in hormetic effect assessment. PMID:19809544

The Effect of Ionic Liquid Pretreatment on the Bioconversion of Tomato Processing Waste to Fermentable Sugars and Biogas.

PubMed

Allison, Brittany J; Cádiz, Juan Canales; Karuna, Nardrapee; Jeoh, Tina; Simmons, Christopher W

2016-08-01

Tomato pomace is an abundant lignocellulosic waste stream from industrial tomato processing and therefore a potential feedstock for production of renewable biofuels. However, little research has been conducted to determine if pretreatment can enhance release of fermentable sugars from tomato pomace. Ionic liquids (ILs) are an emerging pretreatment technology for lignocellulosic biomass to increase enzymatic digestibility and biofuel yield while utilizing recyclable chemicals with low toxicity. In this study, pretreatment of tomato pomace with the ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) was investigated. Changes in pomace enzymatic digestibility were affected by pretreatment time and temperature. Certain pretreatment conditions significantly improved reducing sugar yield and hydrolysis time compared to untreated pomace. Compositional analyses suggested that pretreatment primarily removed water-soluble compounds and enriched for lignocellulose in pomace, with only subtle changes to the composition of the lignocellulose. While tomato pomace was effectively pretreated with [C2mim][OAc] to improve enzymatic digestibility, as of yet, unknown factors in the pomace caused ionic liquid pretreatment to negatively affect anaerobic digestion of pretreated material. This result, which is unique compared to similar studies on IL pretreatment of grasses and woody biomass, highlights the need for additional research to determine how the unique chemical composition of tomato pomace and other lignocellulosic fruit residues may interact with ionic liquids to generate inhibitors for downstream fermentation to biofuels.

Electrochemical pretreatment of waste activated sludge: effect of process conditions on sludge disintegration degree and methane production.

PubMed

Ye, Caihong; Yuan, Haiping; Dai, Xiaohu; Lou, Ziyang; Zhu, Nanwen

2016-11-01

Waste activated sludge (WAS) requires a long digestion time because of a rate-limiting hydrolysis step - the first phase of anaerobic digestion (AD). Pretreatment can be used prior to AD to facilitate the hydrolysis step and improve the efficiency of WAS digestion. This study evaluated a novel application of electrochemical (EC) technology employed as the pretreatment method prior to AD of WAS, focusing on the effect of process conditions on sludge disintegration and subsequent AD process. A superior process condition of EC pretreatment was obtained by reaction time of 30 min, electrolysis voltage of 20 V, and electrode distance of 5 cm, under which the disintegration degree of WAS ranged between 9.02% and 9.72%. In the subsequent batch AD tests, 206 mL/g volatile solid (VS) methane production in EC pretreated sludge was obtained, which was 20.47% higher than that of unpretreated sludge. The AD time was 19 days shorter for EC pretreated sludge compared to the unpretreated sludge. Additionally, the EC + AD reactor achieved 41.84% of VS removal at the end of AD. The analysis of energy consumption showed that EC pretreatment could be effective in enhancing sludge AD with reduced energy consumption when compared to other pretreatment methods.

Lignocellulosic biomass pretreatment using AFEX.

PubMed

Balan, Venkatesh; Bals, Bryan; Chundawat, Shishir P S; Marshall, Derek; Dale, Bruce E

2009-01-01

Although cellulose is the most abundant organic molecule, its susceptibility to hydrolysis is restricted due to the rigid lignin and hemicellulose protection surrounding the cellulose micro fibrils. Therefore, an effective pretreatment is necessary to liberate the cellulose from the lignin-hemicellulose seal and also reduce cellulosic crystallinity. Some of the available pretreatment techniques include acid hydrolysis, steam explosion, ammonia fiber expansion (AFEX), alkaline wet oxidation, and hot water pretreatment. Besides reducing lignocellulosic recalcitrance, an ideal pretreatment must also minimize formation of degradation products that inhibit subsequent hydrolysis and fermentation. AFEX is an important pretreatment technology that utilizes both physical (high temperature and pressure) and chemical (ammonia) processes to achieve effective pretreatment. Besides increasing the surface accessibility for hydrolysis, AFEX promotes cellulose decrystallization and partial hemicellulose depolymerization and reduces the lignin recalcitrance in the treated biomass. Theoretical glucose yield upon optimal enzymatic hydrolysis on AFEX-treated corn stover is approximately 98%. Furthermore, AFEX offers several unique advantages over other pretreatments, which include near complete recovery of the pretreatment chemical (ammonia), nutrient addition for microbial growth through the remaining ammonia on pretreated biomass, and not requiring a washing step during the process which facilitates high solid loading hydrolysis. This chapter provides a detailed practical procedure to perform AFEX, design the reactor, determine the mass balances, and conduct the process safely.

Lignocellulosic Biomass Pretreatment Using AFEX

NASA Astrophysics Data System (ADS)

Balan, Venkatesh; Bals, Bryan; Chundawat, Shishir P. S.; Marshall, Derek; Dale, Bruce E.

Although cellulose is the most abundant organic molecule, its susceptibility to hydrolysis is restricted due to the rigid lignin and hemicellulose protection surrounding the cellulose micro fibrils. Therefore, an effective pretreatment is necessary to liberate the cellulose from the lignin-hemicellulose seal and also reduce cellulosic crystallinity. Some of the available pretreatment techniques include acid hydrolysis, steam explosion, ammonia fiber expansion (AFEX), alkaline wet oxidation, and hot water pretreatment. Besides reducing lignocellulosic recalcitrance, an ideal pretreatment must also minimize formation of degradation products that inhibit subsequent hydrolysis and fermentation. AFEX is an important pretreatment technology that utilizes both physical (high temperature and pressure) and chemical (ammonia) processes to achieve effective pretreatment. Besides increasing the surface accessibility for hydrolysis, AFEX promotes cellulose decrystallization and partial hemicellulose depolymerization and reduces the lignin recalcitrance in the treated biomass. Theoretical glucose yield upon optimal enzymatic hydrolysis on AFEX-treated corn stover is approximately 98%. Furthermore, AFEX offers several unique advantages over other pretreatments, which include near complete recovery of the pretreatment chemical (ammonia), nutrient addition for microbial growth through the remaining ammonia on pretreated biomass, and not requiring a washing step during the process which facilitates high solid loading hydrolysis. This chapter provides a detailed practical procedure to perform AFEX, design the reactor, determine the mass balances, and conduct the process safely.

Effectiveness of a Pre-treatment Snack on the Uptake of Mass Treatment for Schistosomiasis in Uganda: A Cluster Randomized Trial

PubMed Central

Muhumuza, Simon; Olsen, Annette; Katahoire, Anne; Kiragga, Agnes N.; Nuwaha, Fred

2014-01-01

Background School-based mass treatment with praziquantel is the cornerstone for schistosomiasis control in school-aged children. However, uptake of treatment among school-age children in Uganda is low in some areas. The objective of the study was to examine the effectiveness of a pre-treatment snack on uptake of mass treatment. Methods and Findings In a cluster randomized trial carried out in Jinja district, Uganda, 12 primary schools were randomized into two groups; one received education messages for schistosomiasis prevention for two months prior to mass treatment, while the other, in addition to the education messages, received a pre-treatment snack shortly before mass treatment. Four weeks after mass treatment, uptake of praziquantel was assessed among a random sample of 595 children in the snack schools and 689 children in the non-snack schools as the primary outcome. The occurrence of side effects and the prevalence and mean intensity of Schistosoma mansoni infection were determined as the secondary outcomes. Uptake of praziquantel was higher in the snack schools, 93.9% (95% CI 91.7%–95.7%), compared to that in the non-snack schools, 78.7% (95% CI 75.4%–81.7%) (p = 0.002). The occurrence of side effects was lower in the snack schools, 34.4% (95% CI 31.5%–39.8%), compared to that in the non-snack schools, 46.9% (95% CI 42.2%–50.7%) (p = 0.041). Prevalence and mean intensity of S. mansoni infection was lower in the snack schools, 1.3% (95% CI 0.6%–2.6%) and 38.3 eggs per gram of stool (epg) (95% CI 21.8–67.2), compared to that in the non-snack schools, 14.1% (95% CI 11.6%–16.9%) (p = 0.001) and 78.4 epg (95% CI 60.6–101.5) (p = 0.001), respectively. Conclusions Our results suggest that provision of a pre-treatment snack combined with education messages achieves a higher uptake compared to the education messages alone. The use a pre-treatment snack was associated with reduced side effects as well as decreased prevalence and intensity of S. mansoni infection. Trial registration www.ClinicalTrials.gov NCT01869465 Please see later in the article for the Editors' Summary PMID:24824051

Examination of lignocellulosic fibers for chemical, thermal, and separations properties: Addressing thermo-chemical stability issues

NASA Astrophysics Data System (ADS)

Johnson, Carter David

Natural fiber-plastic composites incorporate thermoplastic resins with fibrous plant-based materials, sometimes referred to as biomass. Pine wood mill waste has been the traditional source of natural fibrous feedstock. In anticipation of a waste wood shortage other fibrous biomass materials are being investigated as potential supplements or replacements. Perennial grasses, agricultural wastes, and woody biomass are among the potential source materials. As these feedstocks share the basic chemical building blocks; cellulose, hemicellulose, and lignin, they are collectively called lignocellulosics. Initial investigation of a number of lignocellulosic materials, applied to fiber-plastic composite processing and material testing, resulted in varied results, particularly response to processing conditions. Less thermally stable lignocellulosic filler materials were physically changed in observable ways: darkened color and odor. The effect of biomass materials' chemical composition on thermal stability was investigated an experiment involving determination of the chemical composition of seven lignocellulosics: corn hull, corn stover, fescue, pine, soy hull, soy stover, and switchgrass. These materials were also evaluated for thermal stability by thermogravimetric analysis. The results of these determinations indicated that both chemical composition and pretreatment of lignocellulosic materials can have an effect on their thermal stability. A second study was performed to investigate what effect different pretreatment systems have on hybrid poplar, pine, and switchgrass. These materials were treated with hot water, ethanol, and a 2:1 benzene/ethanol mixture for extraction times of: 1, 3, 6, 12, and 24 hours. This factorial experiment demonstrated that both extraction time and medium have an effect on the weight percent of extractives removed from all three material types. The extracted materials generated in the above study were then subjected to an evaluation of thermal stability by thermogravimetric analysis in a subsequent experiment. Overlay plots, combining individual weight loss curves, demonstrate that the experimental factors, solvent system and extraction time, produce effects on the thermal stability of the treated biomass samples. These data also indicated that the individual lignocellulosic materials had unique responses to the type of solvent used for pretreatment. Increasing extraction time had either no correlation with or a positive effect on thermal stability of the biomass samples.

The induction of menadione stress tolerance in the marine microalga, Dunaliella viridis, through cold pretreatment and modulation of the ascorbate and glutathione pools.

PubMed

Madadkar Haghjou, Maryam; Colville, Louise; Smirnoff, Nicholas

2014-11-01

The effect of cold pretreatment on menadione tolerance was investigated in the cells of the marine microalga, Dunaliella viridis. In addition, the involvement of ascorbate and glutathione in the response to menadione stress was tested by treating cell suspensions with l-galactono-1,4-lactone, an ascorbate precursor, and buthionine sulfoximine, an inhibitor of glutathione synthesis. Menadione was highly toxic to non cold-pretreated cells, and caused a large decrease in cell number. Cold pretreatment alleviated menadione toxicity and cold pretreated cells accumulated lower levels of reactive oxygen species, and had enhanced antioxidant capacity due to increased levels of β-carotene, reduced ascorbate and total glutathione compared to non cold-pretreated cells. Cold pretreatment also altered the response to l-galactono-1,4-lactone and buthionine sulfoximine treatments. Combined l-galactono-1,4-lactone and menadione treatment was lethal in non-cold pretreated cells, but in cold-pretreated cells it had a positive effect on cell numbers compared to menadione alone. Overall, exposure of Dunaliella cells to cold stress enhanced tolerance to subsequent oxidative stress induced by menadione. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Biotechnological application of sustainable biogas production through dry anaerobic digestion of Napier grass.

PubMed

Dussadee, Natthawud; Ramaraj, Rameshprabu; Cheunbarn, Tapana

2017-05-01

Napier grass (Pennisetum purpureum), represents an interesting substrate for biogas production. The research project evaluated biogas potential production from dry anaerobic digestion of Napier grass using batch experiment. To enhance the biogas production from ensiled Napier grass, thermal and alkaline pre-treatments were performed in batch mode. Alkali hydrolysis of Napier grass was performed prior to batch dry anaerobic digestion at three different mild concentrations of sodium hydroxide (NaOH). The study results confirmed that NaOH pretreated sample produced high yield of biogas than untreated (raw) and hot water pretreated samples. Napier grass was used as the mono-substrate. The biogas composition of carbon dioxide (30.10%), methane (63.50%) and 5 ppm of H 2 S was estimated from the biogas. Therefore, fast-growing, high-yielding and organic matter-enriched of Napier grass was promising energy crop for biogas production.

Assessing mechanical deconstruction of softwood cell wall for cellulosic biofuels production

NASA Astrophysics Data System (ADS)

Jiang, Jinxue

Mechanical deconstruction offers a promising strategy to overcome biomass recalcitrance for facilitating enzymatic hydrolysis of pretreated substrates with zero chemicals input and presence of inhibitors. The goal of this dissertation research is to gain a more fundamental understanding on the impact of mechanical pretreatment on generating digestible micronized-wood and how the physicochemical characteristics influence the subsequent enzymatic hydrolysis of micronized wood. The initial moisture content of feedstock was found to be the key factor affecting the development of physical features and enzymatic hydrolysis of micronized wood. Lower moisture content resulted in much rounder particles with lower crystallinity, while higher moisture content resulted in the milled particles with larger aspect ratio and crystallinity. The enzymatic hydrolysis of micronized wood was improved as collectively increasing surface area (i.e., reducing particle size and aspect ratio) and decreasing crystallinity during mechanical milling pretreatment. Energy efficiency analysis demonstrated that low-moisture content feedstock with multi-step milling process would contribute to cost-effectiveness of mechanical pretreatment for achieving more than 70% of total sugars conversion. In the early stage of mechanical pretreatment, the types of cell fractures were distinguished by the initial moisture contents of wood, leading to interwall fracture at the middle lamella region for low moisture content samples and intrawall fracture at the inner cell wall for high moisture content samples. The changes in cell wall fractures also resulted in difference in the distribution of surface chemical composition and energy required for milling process. In an effort to exploit the underlying mechanism associated with the reduced recalcitrance in micronized wood, we reported the increased enzymatic sugar yield and correspondingly structural and accessible properties of micronized feedstock. Electronic microscopy analysis detailed the structural alternation of cell wall during mechanical process, including cell fracture and delamination, ultrastructure disintegration, and cell wall fragments amorphization, as coincident with the particle size reduction. It was confirmed with Simons' staining that longer milling time resulted in increased substrate accessibility and porosity. The changes in cellulose molecular structure with respect to degree of polymerization (DP) and crystallinity index (CrI) also benefited to decreasing recalcitrance and facilitating enzymatic hydrolysis of micronized wood.

Effect of lignin content on changes occurring in poplar cellulose ultrastructure during dilute acid pretreatment

DOE PAGES

Sun, Qining; Foston, Marcus; Meng, Xianzhi; ...

2014-10-14

Obtaining a better understanding of the complex mechanisms occurring during lignocellulosic deconstruction is critical to the continued growth of renewable biofuel production. A key step in bioethanol production is thermochemical pretreatment to reduce plant cell wall recalcitrance for downstream processes. Previous studies of dilute acid pretreatment (DAP) have shown significant changes in cellulose ultrastructure that occur during pretreatment, but there is still a substantial knowledge gap with respect to the influence of lignin on these cellulose ultrastructural changes. This study was designed to assess how the presence of lignin influences DAP-induced changes in cellulose ultrastructure, which might ultimately have largemore » implications with respect to enzymatic deconstruction efforts. Native, untreated hybrid poplar (Populus trichocarpa x Populus deltoids) samples and a partially delignified poplar sample (facilitated by acidic sodium chlorite pulping) were separately pretreated with dilute sulfuric acid (0.10 M) at 160°C for 15 minutes and 35 minutes, respectively . Following extensive characterization, the partially delignified biomass displayed more significant changes in cellulose ultrastructure following DAP than the native untreated biomass. With respect to the native untreated poplar, delignified poplar after DAP (in which approximately 40% lignin removal occurred) experienced: increased cellulose accessibility indicated by increased Simons’ stain (orange dye) adsorption from 21.8 to 72.5 mg/g, decreased cellulose weight-average degree of polymerization (DP w) from 3087 to 294 units, and increased cellulose crystallite size from 2.9 to 4.2 nm. These changes following DAP ultimately increased enzymatic sugar yield from 10 to 80%. We conclude that, overall, the results indicate a strong influence of lignin content on cellulose ultrastructural changes occurring during DAP. With the reduction of lignin content during DAP, the enlargement of cellulose microfibril dimensions and crystallite size becomes more apparent. Further, this enlargement of cellulose microfibril dimensions is attributed to specific processes, including the co-crystallization of crystalline cellulose driven by irreversible inter-chain hydrogen bonding (similar to hornification) and/or cellulose annealing that converts amorphous cellulose to paracrystalline and crystalline cellulose. Essentially, lignin acts as a barrier to prevent cellulose crystallinity increase and cellulose fibril coalescence during DAP.« less

Effect of pre-treatments on the production of biofuels from Phaeodactylum tricornutum.

PubMed

Caporgno, M P; Olkiewicz, M; Torras, C; Salvadó, J; Clavero, E; Bengoa, C

2016-07-15

Several characteristics make Phaeodactylum tricornutum potential candidate for biofuels production such as methane and biodiesel. For this reason, some alternatives are evaluated in this manuscript to improve the conversion of this microalgae into methane. One of these alternatives is the addition of sewage sludge to Phaeodactylum tricornutum for anaerobic co-digestion. Although the co-digestion resulted in lack of synergy, the absence of inhibition indicated that both substrates could be co-digested under certain circumstances, for example if microalgae are cultivated for wastewater treatment purposes. The extraction of lipids using organic solvents has been evaluated for biodiesel production but also as a pre-treatment for anaerobic digestion. The results revealed that the type of solvent influences lipid and biodiesel yields. The high polarity of the mixture methanol/hexane increased the lipid and the biodiesel yields from 10 ± 1 to 53 ± 2 gLipids/100 gVS and from 7 ± 1 to 11 ± 1 gBiodiesel/100 gVS compared with hexane. However, none of these solvents affected the composition of biodiesel. Regarding the methane production after the extraction, it yielded 257 ± 8 and 180 ± 6 mLCH4/gVS from lipid-extracted P. tricornutum using hexane and methanol/hexane respectively. The methane production from the raw microalga was 258 ± 5 mLCH4/gVS in the same experiment. The difference in methane production, mainly after the extraction with methanol/hexane, was a consequence of the changes in the composition of the microalgae after extraction. The extraction did not influence the biodegradability. The ultrasonic pre-treatment prior anaerobic digestion completely disrupted the microalgae cells, but the solubilisation of the organic fraction was scarce (<9.5%). The methane production from pre-treated samples was barely 10-11% higher than the obtained from non pre-treated samples, indicating that the refractory nature of the organic fraction in P. tricornutum is the main obstacle for the methane production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bleach boosting effect of xylanase A from Bacillus halodurans C-125 in ECF bleaching of wheat straw pulp.

PubMed

Lin, Xiao-qiong; Han, Shuang-yan; Zhang, Na; Hu, Hui; Zheng, Sui-ping; Ye, Yan-rui; Lin, Ying

2013-02-05

Past studies have revealed major difficulties in applications of xylanase in the pulp and paper industry as enzymes isolated from many different species could not tolerate high temperatures or highly alkaline conditions. The thermostable xylanase A from Bacillus halodurans C-125 (C-125 xylanase A) was successfully cloned and expressed in Pichia pastoris with a yield as high as 3361 U/mL in a 2 L reactor. Its thermophilic and basophilic properties (optimal activity at 70 °C and pH 9.0), together with the fact it is cellulase-free, render this enzyme attractive for compatible applications in the pulp and paper industry. The pretreatment of wheat straw pulp with C-125 xylanase A at pH 9.0 and 70 °C for 90 min induced the release of both chromophores (Ab(237), Ab(254), Ab(280)) and hydrophobic compounds (Ab(465)) into the filtrate as well as sugar degradation. Moreover, the addition of 10 U xylanase to 1 g wheat straw pulp (dry weight) as pretreatment improved brightness by 5.2% ISO and decreased the kappa number by 5.0% when followed by hydrogen peroxide bleaching. In addition, compared with two commercial enzymes, Pulpzyme HC and AU-PE89, which are normally incorporated in ECF bleaching of wheat straw pulp, C-125 xylanase A proved to be more effective in enhancing brightness as well as preserving paper strength properties. When evaluating the physical properties of pulp samples, such as tensile index, tearing index, bursting index, and post-color (PC) number, the enzymes involved in pretreating pulps exhibited better or the same performances as chemical treatment. Compared with chemical bleaching, chlorine consumption can be significantly reduced by 10% for xylanase-pretreated wheat straw pulp while maintaining the brightness together with the kappa number at the same level. Scanning electron microscopy revealed significant surface modification of enzyme-pretreated pulp fibers with no marked fiber disruptions. Copyright © 2012 Elsevier Inc. All rights reserved.

Effect of structural changes of lignocelluloses material upon pre-treatment using green solvents

NASA Astrophysics Data System (ADS)

Gunny, Ahmad Anas Nagoor; Arbain, Dachyar; Jamal, Parveen

2017-04-01

The Malaysia Biomass strategy 2020 stated that the key step of biofuel production from biomass lies on the pretreatment process. Conventional `pre-treatment' methods are `non-green" and costly. The recent green and cost-effective biomass pretreatment is using new generation of Ionic Liquids also known as Deep Eutectic Solvents (DESs). DESs are made of renewable components are cheaper, greener and the process synthesis are easier. Thus, the present paper concerns with the preparation of various combination of DES and to study the effect of DESs pretreatment process on microcrystalline cellulose (MCC), a model substrate. The crystalline structural changes were studied using using X-ray Diffraction Methods, Fourier Transformed Infrared Spectroscopy (FTIR) and surface area and pore size analysis. Results showed reduction of crystalline structure of MCC treated with the DESs and increment of surface area and pore size of MCC after pre-treatment process. These results indicated the DES has successfully converted the lignocelluloses material in the form suitable for hydrolysis and conversion to simple sugar.

The effect of a combined biological and thermo-mechanical pretreatment of wheat straw on energy yields in coupled ethanol and methane generation.

PubMed

Theuretzbacher, Franz; Blomqvist, Johanna; Lizasoain, Javier; Klietz, Lena; Potthast, Antje; Horn, Svein Jarle; Nilsen, Paal J; Gronauer, Andreas; Passoth, Volkmar; Bauer, Alexander

2015-10-01

Ethanol and biogas are energy carriers that could contribute to a future energy system independent of fossil fuels. Straw is a favorable bioenergy substrate as it does not compete with food or feed production. As straw is very resistant to microbial degradation, it requires a pretreatment to insure efficient conversion to ethanol and/or methane. This study investigates the effect of combining biological pretreatment and steam explosion on ethanol and methane yields in order to improve the coupled generation process. Results show that the temperature of the steam explosion pretreatment has a particularly strong effect on possible ethanol yields, whereas combination with the biological pretreatment showed no difference in overall energy yield. The highest overall energy output was found to be 10.86 MJ kg VS(-1) using a combined biological and steam explosion pretreatment at a temperature of 200°C. Copyright © 2015 Elsevier Ltd. All rights reserved.

The anaerobic digestion of biologically and physicochemically pretreated oily wastewater.

PubMed

Peng, Liyu; Bao, Meidan; Wang, Qingfeng; Wang, Fangchao; Su, Haijia

2014-01-01

To enhance the degradation of oily wastewater and its biogas production, a biological-physicochemical pretreatment was introduced prior to the anaerobic digestion system. The digestion thereafter proceeded more efficiently due to the inoculation by oil degrading bacteria (Bacillus). A 2-stage pre-mixing is more effective than directly mixing. The effects on the methane production were also investigated by pre-treatment with ultrasonic (US) treatment, combined with citric acid (CA) addition. US pre-treatment was found to improve the initial methane production, and CA pre-treatment could maintain this improvement during the whole digestion stage. Pre-mixing Bacillus at 9 wt.% inoculation, combined with US for 10 min and a CA concentration of 500 mg/L provided the optimum conditions. The most effective enhancement of methane yield was 1100.46 ml/g VS, exceeding that of the control by 280%. The change of coenobium shape and fatty acid content further proved that such pretreatment of oily wastewater can facilitate digestion. Copyright © 2013 Elsevier Ltd. All rights reserved.

Application of a simple column-switching ion chromatography technique for removal of matrix interferences and sensitive fluorescence determination of acidic compounds (pharmaceutical drugs) in complex samples.

PubMed

Muhammad, Nadeem; Subhani, Qamar; Wang, Fenglian; Guo, Dandan; Zhao, Qiming; Wu, Shuchao; Zhu, Yan

2017-09-15

This work illustrates the introduction of a simple, rugged and flexible column-switching ion chromatography (IC) technique for an automated on-line QuEChERS extracted samples extracts washing followed by sensitive fluorescence (FLD) determination of five acidic pharmaceutical drugs namely; clofibric acid (CLO), ibuprofen (IBU), aspirin (ASP), naproxen (NAP) and flurobrofen (FLU) in three complex samples (spinach, apple and hospital sewage sludge). An old anion exchange column IonPac ® AS11-HC was utilized as a pre-treatment column for on-line washing of inorganic and organic interferences followed by isocratic separation of five acidic drugs with another anion exchange IonPac ® AS12A analytical column by exploiting the column-switching technique. This novel method exhibited good linearity with correlation coefficients (r 2 ) for all drugs were in the range 0.976-0.996. The limit of detection and quantification of all five acidic drugs were in the range 0.024μg/kg to 8.70μg/kg and 0.082μg/kg to 0.029mg/kg, respectively, and better recoveries in the range 81.17-112.5% with percentage relative standard deviations (RSDs) less than 17.8% were obtained. This on-line sample pre-treatment method showed minimum matrix effect in the range of 0.87-1.25 except for aspirin. This simple rugged and flexible column-switching system required only 28min for maximum elimination of matrices and interferences in three complex samples extracts, isocratic separation of five acidic drugs and for the continuous regeneration of pre-treatment column prior to every subsequent analysis. Finally, this simple automated IC system was appeared so rugged and flexible, which can eliminate and wash out most of interference, impurities and matrices in complex samples, simply by adjusting the NaOH and acetonitrile concentration in washing mobile phase with maximum recoveries of acidic analytes of interest. Copyright © 2017. Published by Elsevier B.V.

Improved radiocarbon dating for contaminated archaeological bone collagen, silk, wool and hair samples via cross-flow nanofiltrated amino acids.

PubMed

Boudin, Mathieu; Boeckx, Pascal; Vandenabeele, Peter; Van Strydonck, Mark

2013-09-30

Radiocarbon dating and stable isotope analyses of bone collagen, wool, hair and silk contaminated with extraneous carbon (e.g. humic substances) does not yield reliable results if these materials are pre-treated using conventional methods. A cross-flow nanofiltration method was developed that can be applied to various protein materials like collagen, hair, silk, wool and leather, and should be able to remove low-molecular and high-molecular weight contaminants. To avoid extraneous carbon contamination via the filter a ceramic filter (molecular weight cut-off of 200 Da) was used. The amino acids, released by hot acid hydrolysis of the protein material, were collected in the permeate and contaminants in the retentate (>200 Da). (14)C-dating results for various contaminated archaeological samples were compared for bulk material (pre-treated with the conventional methods) and for cross-flow nanofiltrated amino acids (permeate) originating from the same samples. Contamination and quality control of (14)C dates of bulk and permeate samples were obtained by measuring C:N ratios, fluorescence spectra, and δ(13)C and δ(15)N values of the samples. Cross-flow nanofiltration decreases the C:N ratio which means that contaminants have been removed. Cross-flow nanofiltration clearly improved sample quality and (14)C results. It is a quick and non-labor-intensive technique and can easily be implemented in any (14)C and stable isotope laboratory for routine sample pre-treatment analyses. Copyright © 2013 John Wiley & Sons, Ltd.

Cell-wall structural changes in wheat straw pretreated for bioethanol production

Treesearch

Jan B. Kristensen; G. Thygesen Lisbeth; Claus Felby; Henning Jorgensen; Thomas Elder

2008-01-01

Pretreatment is an essential step in the enzymatic hydrolysis of biomass and subsequent production of bioethanol. Recent results indicate that only a mild pretreatment is necessary in an industrial, economically feasible system. The Integrated Biomass Utilisation System hydrothermal pretreatment process has previously been shown to be effective in preparing wheat straw...

Biochemical methane potential from sewage sludge: Effect of an aerobic pretreatment and fly ash addition as source of trace elements.

PubMed

Huiliñir, César; Pinto-Villegas, Paula; Castillo, Alejandra; Montalvo, Silvio; Guerrero, Lorna

2017-06-01

The effect of aerobic pretreatment and fly ash addition on the production of methane from mixed sludge is studied. Three assays with pretreated and not pretreated mixed sludge in the presence of fly ash (concentrations of 0, 10, 25, 50, 250 and 500mg/L) were run at mesophilic condition. It was found that the combined use of aerobic pretreatment and fly ash addition increases methane production up to 70% when the fly ash concentrations were lower than 50mg/L, while concentrations higher than 250mg/L cause up to 11% decrease of methane production. For the anaerobic treatment of mixed sludge without pretreatment, the fly ash improved methane generation at all the concentrations studied, with a maximum of 56%. The removal of volatile solids does not show an improvement compared to the separate use of an aerobic pre-treatment and fly ash addition. Therefore, the combined use of the aerobic pre-treatment and fly ash addition improves only the production of methane. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison of seven types of thermo-chemical pretreatments on the structural features and anaerobic digestion of sunflower stalks.

PubMed

Monlau, F; Barakat, A; Steyer, J P; Carrere, H

2012-09-01

Sunflower stalks can be used for the production of methane, but their recalcitrant structure requires the use of thermo-chemical pretreatments. Two thermal (55 and 170°C) and five thermo-chemical pretreatments (NaOH, H(2)O(2), Ca(OH)(2), HCl and FeCl(3)) were carried out, followed by anaerobic digestion. The highest methane production (259 ± 6 mL CH(4)g(-1) VS) was achieved after pretreatment at 55°C with 4% NaOH for 24h. Acidic pretreatments at 170°C removed more than 90% of hemicelluloses and uronic acids whereas alkaline and oxidative pretreatments were more effective in dissolving lignin. However, no pretreatment was effective in reducing the crystallinity of cellulose. Methane production rate was positively correlated with the amount of solubilized matter whereas methane potential was negatively correlated with the amount of lignin. Considering that the major challenge is obtaining increased methane potential, alkaline pretreatments can be recommended in order to optimize the anaerobic digestion of lignocellulosic substrates. Copyright © 2012 Elsevier Ltd. All rights reserved.

Technospheric Mining of Rare Earth Elements from Bauxite Residue (Red Mud): Process Optimization, Kinetic Investigation, and Microwave Pretreatment.

PubMed

Reid, Sable; Tam, Jason; Yang, Mingfan; Azimi, Gisele

2017-11-10

Some rare earth elements (REEs) are classified under critical materials, i.e., essential in use and subject to supply risk, due to their increasing demand, monopolistic supply, and environmentally unsustainable and expensive mining practices. To tackle the REE supply challenge, new initiatives have been started focusing on their extraction from alternative secondary resources. This study puts the emphasis on technospheric mining of REEs from bauxite residue (red mud) produced by the aluminum industry. Characterization results showed the bauxite residue sample contains about 0.03 wt% REEs. Systematic leaching experiments showed that concentrated HNO 3 is the most effective lixiviant. However, because of the process complexities, H 2 SO 4 was selected as the lixiviant. To further enhance the leaching efficiency, a novel process based on microwave pretreatment was employed. Results indicated that microwave pretreatment creates cracks and pores in the particles, enabling the lixiviant to diffuse further into the particles, bringing more REEs into solution, yielding of 64.2% and 78.7% for Sc and Nd, respectively, which are higher than the maximum obtained when HNO 3 was used. This novel process of "H 2 SO 4 leaching-coupled with-microwave pretreatment" proves to be a promising technique that can help realize the technological potential of REE recovery from secondary resources, particularly bauxite residue.

Lip line changes in Class III facial asymmetry patients after orthodontic camouflage treatment, one-jaw surgery, and two-jaw surgery: A preliminary study.

PubMed

Lee, Gung-Chol; Yoo, Jo-Kwang; Kim, Seong-Hun; Moon, Cheol-Hyun

2017-03-01

To evaluate the effects of orthodontic camouflage treatment (OCT), one-jaw surgery, and two-jaw surgery on the correction of lip line cant (LLC) and to examine factors affecting the correction of LLC in Class III craniofacial asymmetry patients. A sample of 30 Class III craniofacial asymmetry patients was divided into OCT (n = 10), one-jaw surgery (n = 10), and two-jaw surgery (n = 10) groups such that the pretreatment LLC was similar in each group. Pretreatment and posttreatment cone-beam computed tomography scans were used to measure dental and skeletal parameters and LLC. Pretreatment and posttreatment measurements were compared within groups and between groups. Pearson's correlation tests and multiple regression analyses were performed to investigate factors affecting the amount and rate of LLC correction. The average LLC correction was 1.00° in the one-jaw surgery group, and in the two-jaw surgery group, it was 1.71°. In the OCT group it was -0.04°, which differed statistically significantly from the LLC correction in the other two groups. The amount and rate of LLC correction could be explained by settling of skeletal discrepancies or LLC at pretreatment with goodness of fit percentages of approximately 82% and 41%, respectively. Orthognathic surgery resulted in significant correction of LLC in Class III craniofacial asymmetry patients, while OCT did not.

Influence of previous acid etching on bond strength of universal adhesives to enamel and dentin.

PubMed

Torres, Carlos Rocha Gomes; Zanatta, Rayssa Ferreira; Silva, Tatiane Josefa; Huhtala, Maria Filomena Rocha Lima; Borges, Alessandra Bühler

2017-01-01

The objective of this study was to evaluate the effect of acid pretreatment on the bond strength of composite resin bonded to enamel and dentin with 2 different universal self-etching adhesives. The null hypothesis was that the acid treatment performed prior to adhesive application would not significantly change the bond strength to enamel or dentin for either universal adhesive tested. A sample of 112 bovine incisors were selected and embedded in acrylic resin. Half were ground until a flat enamel surface was obtained, and the other half were polished until a 6 × 6-mm area of dentin was exposed, resulting into 2 groups (n = 56). The enamel and dentin groups were divided into 2 subgroups according to the adhesive system applied: Futurabond U or Scotchbond Universal. Each of these subgroups was divided into 2 additional subgroups (n = 14); 1 subgroup received phosphoric acid pretreatment, and 1 subgroup did not. The bond strength was assessed with a microtensile test. Data from enamel and dentin specimens were analyzed separately using 1-way analysis of variance. The acid pretreatment did not significantly change the bond strength of the adhesives tested, either to enamel (P = 0.4161) or to dentin (P = 0.4857). The acid etching pretreatment did not affect the bond strength to dentin and enamel when the tested universal multipurpose adhesive systems were used.

Simplifying sample pretreatment: application of dried blood spot (DBS) method to blood samples, including postmortem, for UHPLC-MS/MS analysis of drugs of abuse.

PubMed

Odoardi, Sara; Anzillotti, Luca; Strano-Rossi, Sabina

2014-10-01

The complexity of biological matrices, such as blood, requires the development of suitably selective and reliable sample pretreatment procedures prior to their instrumental analysis. A method has been developed for the analysis of drugs of abuse and their metabolites from different chemical classes (opiates, methadone, fentanyl and analogues, cocaine, amphetamines and amphetamine-like substances, ketamine, LSD) in human blood using dried blood spot (DBS) and subsequent UHPLC-MS/MS analysis. DBS extraction required only 100μL of sample, added with the internal standards and then three droplets (30μL each) of this solution were spotted on the card, let dry for 1h, punched and extracted with methanol with 0.1% of formic acid. The supernatant was evaporated and the residue was then reconstituted in 100μL of water with 0.1% of formic acid and injected in the UHPLC-MS/MS system. The method was validated considering the following parameters: LOD and LOQ, linearity, precision, accuracy, matrix effect and dilution integrity. LODs were 0.05-1ng/mL and LOQs were 0.2-2ng/mL. The method showed satisfactory linearity for all substances, with determination coefficients always higher than 0.99. Intra and inter day precision, accuracy, matrix effect and dilution integrity were acceptable for all the studied substances. The addition of internal standards before DBS extraction and the deposition of a fixed volume of blood on the filter cards ensured the accurate quantification of the analytes. The validated method was then applied to authentic postmortem blood samples. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

FIELD-SCALE STUDIES: HOW DOES SOIL SAMPLE PRETREATMENT AFFECT REPRESENTATIVENESS ? (ABSTRACT)

EPA Science Inventory

Samples from field-scale studies are very heterogeneous and can contain large soil and rock particles. Oversize materials are often removed before chemical analysis of the soil samples because it is not practical to include these materials. Is the extracted sample representativ...

FIELD-SCALE STUDIES: HOW DOES SOIL SAMPLE PRETREATMENT AFFECT REPRESENTATIVENESS?

EPA Science Inventory

Samples from field-scale studies are very heterogeneous and can contain large soil and rock particles. Oversize materials are often removed before chemical analysis of the soil samples because it is not practical to include these materials. Is the extracted sample representativ...

HIV-1 drug resistance before initiation or re-initiation of first-line antiretroviral therapy in low-income and middle-income countries: a systematic review and meta-regression analysis.

PubMed

Gupta, Ravindra K; Gregson, John; Parkin, Neil; Haile-Selassie, Hiwot; Tanuri, Amilcar; Andrade Forero, Liliana; Kaleebu, Pontiano; Watera, Christine; Aghokeng, Avelin; Mutenda, Nicholus; Dzangare, Janet; Hone, San; Hang, Zaw Zaw; Garcia, Judith; Garcia, Zully; Marchorro, Paola; Beteta, Enrique; Giron, Amalia; Hamers, Raph; Inzaule, Seth; Frenkel, Lisa M; Chung, Michael H; de Oliveira, Tulio; Pillay, Deenan; Naidoo, Kogie; Kharsany, Ayesha; Kugathasan, Ruthiran; Cutino, Teresa; Hunt, Gillian; Avila Rios, Santiago; Doherty, Meg; Jordan, Michael R; Bertagnolio, Silvia

2018-03-01

Pretreatment drug resistance in people initiating or re-initiating antiretroviral therapy (ART) containing non-nucleoside reverse transcriptase inhibitors (NNRTIs) might compromise HIV control in low-income and middle-income countries (LMICs). We aimed to assess the scale of this problem and whether it is associated with the intiation or re-initiation of ART in people who have had previous exposure to antiretroviral drugs. This study was a systematic review and meta-regression analysis. We assessed regional prevalence of pretreatment drug resistance and risk of pretreatment drug resistance in people initiating ART who reported previous ART exposure. We systematically screened publications and unpublished datasets for pretreatment drug-resistance data in individuals in LMICs initiating or re-initiating first-line ART from LMICs. We searched for studies in PubMed and Embase and conference abstracts and presentations from the Conference on Retroviruses and Opportunistic Infections, the International AIDS Society Conference, and the International Drug Resistance Workshop for the period Jan 1, 2001, to Dec 31, 2016. To assess the prevalence of drug resistance within a specified region at any specific timepoint, we extracted study level data and pooled prevalence estimates within the region using an empty logistic regression model with a random effect at the study level. We used random effects meta-regression to relate sampling year to prevalence of pretreatment drug resistance within geographical regions. We identified 358 datasets that contributed data to our analyses, representing 56 044 adults in 63 countries. Prevalence estimates of pretreatment NNRTI resistance in 2016 were 11·0% (7·5-15·9) in southern Africa, 10·1% (5·1-19·4) in eastern Africa, 7·2% (2·9-16·5) in western and central Africa, and 9·4% (6·6-13·2) in Latin America and the Caribbean. There were substantial increases in pretreatment NNRTI resistance per year in all regions. The yearly increases in the odds of pretreatment drug resistance were 23% (95% CI 16-29) in southern Africa, 17% (5-30) in eastern Africa, 17% (6-29) in western and central Africa, 11% (5-18) in Latin America and the Caribbean, and 11% (2-20) in Asia. Estimated increases in the absolute prevalence of pretreatment drug resistance between 2015 and 2016 ranged from 0·3% in Asia to 1·8% in southern Africa. Pretreatment drug resistance is increasing at substantial rate in LMICs, especially in sub-Saharan Africa. In 2016, the prevalence of pretreatment NNRTI resistance was near WHO's 10% threshold for changing first-line ART in southern and eastern Africa and Latin America, underscoring the need for routine national HIV drug-resistance surveillance and review of national policies for first-line ART regimen composition. Bill & Melinda Gates Foundation and World Health Organization. Copyright © 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.

Pretreatment of empty fruit bunch from oil palm for fuel ethanol production and proposed biorefinery process.

PubMed

Tan, Liping; Yu, Yongcheng; Li, Xuezhi; Zhao, Jian; Qu, Yinbo; Choo, Yuen May; Loh, Soh Kheang

2013-05-01

This study evaluates the effects of some pretreatment processes to improve the enzymatic hydrolysis of oil palm empty fruit bunch (EFB) for ethanol production. The experimental results show that the bisulfite pretreatment was practical for EFB pretreatment. Moreover, the optimum pretreatment conditions of the bisulfite pretreatment (180 °C, 30 min, 8% NaHSO3, 1% H2SO4) were identified. In the experiments, a biorefinery process of EFB was proposed to produce ethanol, xylose products, and lignosulfonates. Copyright © 2012 Elsevier Ltd. All rights reserved.

Factors affecting seawater-based pretreatment of lignocellulosic date palm residues.

PubMed

Fang, Chuanji; Thomsen, Mette Hedegaard; Frankær, Christian Grundahl; Bastidas-Oyanedel, Juan-Rodrigo; Brudecki, Grzegorz P; Schmidt, Jens Ejbye

2017-12-01

Seawater-based pretreatment of lignocellulosic biomass is an innovative process at research stage. With respect to process optimization, factors affecting seawater-based pretreatment of lignocellulosic date palm residues were studied for the first time in this paper. Pretreatment temperature (180°C-210°C), salinity of seawater (0ppt-50ppt), and catalysts (H 2 SO 4 , Na 2 CO 3 , and NaOH) were investigated. The results showed that pretreatment temperature exerted the largest influence on seawater-based pretreatment in terms of the enzymatic digestibility and fermentability of pretreated solids, and the inhibition of pretreatment liquids to Saccharomyces cerevisiae. Salinity showed the least impact to seawater-based pretreatment, which widens the application spectrum of saline water sources such as brines discharged in desalination plant. Sulfuric acid was the most effective catalyst for seawater-based pretreatment compared with Na 2 CO 3 and NaOH. Copyright © 2017 Elsevier Ltd. All rights reserved.

Multi-pesticides residue analysis of grains using modified magnetic nanoparticle adsorbent for facile and efficient cleanup.

PubMed

Liu, Zhenzhen; Qi, Peipei; Wang, Xiangyun; Wang, Zhiwei; Xu, Xiahong; Chen, Wenxue; Wu, Liyu; Zhang, Hu; Wang, Qiang; Wang, Xinquan

2017-09-01

A facile, rapid sample pretreatment method was developed based on magnetic nanoparticles for multi-pesticides residue analysis of grains. Magnetite (Fe 3 O 4 ) nanoparticles modified with 3-(N,N-diethylamino)propyltrimethoxysilane (Fe 3 O 4 -PSA) and commercial C18 were selected as the cleanup adsorbents to remove the target interferences of the matrix, such as fatty acids and non-polar compounds. Rice was used as the representative grain sample for method optimization. The amount of Fe 3 O 4 -PSA and C18 were systematically investigated for selecting the suitable purification conditions, and the simultaneous determination of 50 pesticides and 8 related metabolites in rice was established by liquid chromatography-tandem mass spectrometry. Under the optimal conditions, the method validation was performed including linearity, sensitivity, matrix effect, recovery and precision, which all satisfy the requirement for pesticides residue analysis. Compared to the conventional QuEChERS method with non-magnetic material as cleanup adsorbent, the present method can save 30% of the pretreatment time, giving the high throughput analysis possible. Copyright © 2017 Elsevier Ltd. All rights reserved.

Eco-friendly process combining physical-chemical and biological technics for the fermented dairy products waste pretreatment and reuse.

PubMed

Kasmi, Mariam; Hamdi, Moktar; Trabelsi, Ismail

2017-01-01

Residual fermented dairy products resulting from process defects or from expired shelf life products are considered as waste. Thus, dairies wastewater treatment plants (WWTP) suffer high input effluents polluting load. In this study, fermented residuals separation from the plant wastewater is proposed. In the aim to meet the municipal WWTP input limits, a pretreatment combining physical-chemical and biological processes was investigated to reduce residual fermented dairy products polluting effect. Yoghurt (Y) and fermented milk products (RL) were considered. Raw samples chemical oxygen demand (COD) values were assessed at 152 and 246 g.L -1 for Y and RL products, respectively. Following the thermal coagulation, maximum removal rates were recorded at 80 °C. Resulting whey stabilization contributed to the removal rates enhance to reach 72% and 87% for Y and RL samples; respectively. Residual whey sugar content was fermented using Candida strains. Bacterial growth and strains degrading potential were discussed. C. krusei strain achieved the most important removal rates of 78% and 85% with Y and RL medium, respectively. Global COD removal rates exceeded 93%.

Determination of proflavine in rat whole blood without sample pretreatment by laser desorption postionization mass spectrometry.

PubMed

Chen, Jiaxin; Hu, Yongjun; Lu, Qiao; Wang, Pengchao; Zhan, Huaqi

2017-04-01

A novel pretreatment-free method involving laser desorption postionization (LDPI) coupled with time-of-flight mass spectrometry (MS) was developed for the monitoring of proflavine level in rat whole blood. It comprises a protocol for dosing via intravenous administration and collection of whole blood, followed by direct LDPI-MS analysis without any sample pretreatment. An intense ion signal at m/z 209 was observed from whole blood without any interference signals, except some background signals below m/z 100. The calibration curve was established with use of 9-phenylacridine as the internal standard for proflavine determination from the plotting of the peak ratios of proflavine to the internal standard, with a correlation coefficient (R 2 ) greater than 0.99. The limit of detection was estimated to be 0.48 pmol/mm 2 and the quantification range was 0.5-16.5 μg/mL for proflavine. In addition, only a minimal matrix effect was observed, as expected from considerations of the desorption and ionization mechanism. Interday and intraday accuracy and precision were calculated to be within 13% and 82-114%, respectively. Estimated concentrations of proflavine residue in whole blood were also successfully obtained at selected time points after dosing. The proposed method is simple, low cost, and sensitive, and should be seen as a complementary method for monitoring drug levels in blood. Graphical Abstract Monitoring proflavine levels in rat whole blood at different time points using laser desorption postionization mass spectrometry (LDPI-MS).

Effect of White Charcoal on COD Reduction in Wastewater Treatment

NASA Astrophysics Data System (ADS)

Pijarn, Nuchanaporn; Butsee, Manipa; Buakul, Kanokwan; Seng, Hasan; Sribuarai, Tinnphat; Phonprasert, Pongtep; Taneeto, Kla; Atthameth, Prasertsil

2017-06-01

The objective of this study is to compare the COD reduction in wastewater between using coconut shell and coconut spathe white charcoal from Khlong Wat NongPra-Ong, Krathumbaen, SamutSakhon province, Thailand. The waste water samples were collected using composite sampling method. The experimental section can be divided into 2 parts. The first part was study the optimum of COD adsorption time using both white charcoals. The second part was study the optimum amount of white charcoal for chemical oxygen demand (COD) reduction. The pre-treatment of wastewater was examined in parameters include temperature, alkalinity (pH), conductivity, turbidity, suspended solid (SS), total dissolved solid (TDS), and COD. The results show that both white charcoals can reduce COD of wastewater. The pH of pre-treatment wastewater had pH 9 but post-treatment wastewaters using both white charcoals have pH 8. The COD of pre-treatment wastewater had COD as 258 mg/L but post-treatment wastewater using coconut shell white charcoal had COD steady at 40 mg/L in 30 min and the amount of white charcoals 4 g. The COD of post-treatment wastewater using coconut spathe white charcoal had COD steady at 71 mg/L in 30 min and the amount of white charcoals 4 g. Therefore comparison of COD reduction between coconut shell white charcoal versus coconut spathe white charcoal found that the coconut shell white charcoal had efficiency for COD reduction better than coconut spathe white charcoal.

Thermophilic bio-hydrogen production from corn-bran residue pretreated by calcined-lime mud from papermaking process.

PubMed

Zhang, Jishi; Zhang, Junjie; Zang, Lihua

2015-12-01

This study investigated the use of calcined-lime mud from papermaking process (CLMP) pretreatment to improve fermentative hydrogen yields from corn-bran residue (CBR). CBR samples were pretreated with different concentrations (0-15 g/L) of CLMP at 55°C for 48 h, prior to the thermophilic fermentation with heat-treated anaerobic sludge inoculum. The maximum hydrogen yield (MHY) of 338.91 ml/g-VS was produced from the CBR pretreated with 10 g/L CLMP, with the corresponding lag-phase time of 8.24h. Hydrogen yield increments increased from 27.76% to 48.07%, compared to the control. The CLMP hydrolyzed more cellulose, which provided adequate substrates for hydrogen production. Copyright © 2015 Elsevier Ltd. All rights reserved.

Simultaneous saccharification and cofermentation of peracetic acid-pretreated biomass.

PubMed

Teixeira, L C; Linden, J C; Schroeder, H A

2000-01-01

Previous work in our laboratories has demonstrated the effectiveness of peracetic acid for improving enzymatic digestibility of lignocellulosic materials. The use of dilute alkali solutions as a pre-pretreatment prior to peracetic acid lignin oxidation increased carbohydrate hydrolysis yields in a synergistic as opposed to additive manner. Deacetylation of xylan is easily achieved using dilute alkali solutions under mild conditions. In this article, we evaluate the effectiveness of peracetic acid combined with an alkaline pre-pretreatment through simultaneous saccharification and cofermentation (SSCF) of pretreated hybrid poplar wood and sugar cane bagasse. Respective ethanol yields of 92.8 and 91.9% of theoretical are achieved using 6% NaOH/15% peracetic acid-pretreated substrates and recombinant Zymomonas mobilis CP4/pZB5. Reduction of acetyl groups of the lignocellulosic materials is demonstrated following alkaline pre-pretreatments. Such processing may be helpful in reducing peracetic acid requirements. The influence of deacetylation is more significant in combined pretreatments using lower peracetic acid loadings.

The effect of biological pretreatment with the selective white-rot fungus Echinodontium taxodii on enzymatic hydrolysis of softwoods and hardwoods.

PubMed

Yu, Hongbo; Guo, Guoning; Zhang, Xiaoyu; Yan, Keliang; Xu, Chunyan

2009-11-01

Selective white-rot fungi have shown potential for lignocellulose pretreatment. In the study, a new fungal isolate, Echinodontium taxodii 2538, was used in biological pretreatment to enhance the enzymatic hydrolysis of two native woods: Chinese willow (hardwood) and China-fir (softwood). E. taxodii preferentially degraded the lignin during the pretreatment, and the pretreated woods showed significant increases in enzymatic hydrolysis ratios (4.7-fold for hardwood and 6.3-fold for softwood). To better understand effects of biological pretreatment on enzymatic hydrolysis, enzyme-substrate interactions were investigated. It was observed that E. taxodii enhanced initial adsorption of cellulase but which did not always translate to high initial hydrolysis rate. However, the rate of change in hydrolysis rate declined dramatically with decreasing irreversible adsorption of cellulase. Thus, the enhancement of enzymatic hydrolysis was attributed to the decline of irreversible adsorption which may result from partial lignin degradation and alteration in lignin structure after biological pretreatment.

Influence of size reduction treatments on sugar recovery from Norway spruce for butanol production.

PubMed

Yang, Ming; Xu, Minyuan; Nan, Yufei; Kuittinen, Suvi; Kamrul Hassan, Md; Vepsäläinen, Jouko; Xin, Donglin; Zhang, Junhua; Pappinen, Ari

2018-06-01

This study investigated whether the effectiveness of pretreatment is limited by a size reduction of Norway spruce wood in biobutanol production. The spruce was milled, chipped, and mashed for hydrogen peroxide-acetic acid (HPAC) and dilute acid (DA) pretreatment. Sugar recoveries from chipped and mashed spruce after enzymatic hydrolysis were higher than from milled spruce, and the recoveries were not correlated with the spruce fiber length. HPAC pretreatment resulted in almost 100% glucose and 88% total reducing sugars recoveries from chipped spruce, which were apparently higher than DA pretreatment, demonstrating greater effectiveness of HPAC pretreatment on sugar production. The butanol and ABE yield from chipped spruce were 126.5 and 201.2 g/kg pretreated spruce, respectively. The yields decreased with decreasing particle size due to biomass loss in the pretreatment. The results suggested that Norway spruce chipped to a 20 mm length is applicable to the production of platform sugars for butanol fermentation. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of Different Sugar Beet Pulp Pretreatments on Biogas Production Efficiency.

PubMed

Ziemiński, Krzysztof; Kowalska-Wentel, Monika

2017-03-01

The objective of this study was to determine the effect of different sugar beet pulp (SBP) pretreatments on biogas yield from anaerobic digestion. SBP was subjected to grinding, thermal-pressure processing, enzymatic hydrolysis, or combination of these pretreatments. It was observed that grinding of SBP to 2.5-mm particles resulted in the cumulative biogas productivity of 617.2 mL/g volatile solids (VS), which was 20.2 % higher compared to the biogas yield from the not pretreated SBP, and comparable to that from not ground, enzymatically hydrolyzed SBP. The highest cumulative biogas productivity, 898.7 mL/g VS, was obtained from the ground, thermal-pressure pretreated and enzymatically hydrolyzed SBP. The latter pretreatment variant enabled to achieve the highest glucose concentration (24.765 mg/mL) in the enzymatic hydrolysates. The analysis of energy balance showed that the increase in the number of SBP pretreatment operations significantly reduced the gain of electric energy.

Ultraviolet resonance Raman spectroscopy for the detection of cocaine in oral fluid

NASA Astrophysics Data System (ADS)

D'Elia, Valentina; Montalvo, Gemma; Ruiz, Carmen García; Ermolenkov, Vladimir V.; Ahmed, Yasmine; Lednev, Igor K.

2018-01-01

Detecting and quantifying cocaine in oral fluid is of significant importance for practical forensics. Up to date, mainly destructive methods or biochemical tests have been used, while spectroscopic methods were only applied to pretreated samples. In this work, the possibility of using resonance Raman spectroscopy to detect cocaine in oral fluid without pretreating samples was tested. It was found that ultraviolet resonance Raman spectroscopy with 239-nm excitation allows for the detection of cocaine in oral fluid at 10 μg/mL level. Further method development will be needed for reaching the practically useful levels of cocaine detection.

Effects of the combination of metyrapone and oxazepam on cocaine-induced increases in corticosterone in the medial prefrontal cortex and nucleus accumbens.

PubMed

Keller, Courtney M; Breaux, Kelly N; Goeders, Nicholas E

2017-03-01

We have previously demonstrated that a combination of drugs (i.e., metyrapone and oxazepam) known to attenuate HPA-axis activity effectively decreases cocaine self-administration and cue reactivity in rats. However, we did not find changes in plasma corticosterone that matched the behavioral effects we observed, indicating that a different mechanism of action must be involved. Therefore, we hypothesized that the combination of metyrapone and oxazepam attenuates cocaine taking and seeking by decreasing cocaine-induced increases in corticosterone in the brain. Male rats were implanted with guide cannulae targeting the medial prefrontal cortex or nucleus accumbens. After the rats recovered from surgery, the microdialysis session was conducted. Rats were housed in the experimental chamber and the dialysis probes inserted into the guide cannulae the night before the session. The following day, dialysate samples were collected over a five-hour session. Baseline samples were collected for the first two hours, every 20min. Samples were then collected following administration of cocaine (15mg/kg, ip). Before injections of cocaine, rats were pretreated with either vehicle or the combination of metyrapone (50mg/kg, ip) and oxazepam (10mg/kg, ip). The administration of cocaine resulted in an increase in corticosterone in the medial prefrontal cortex following vehicle pretreatment, which was not observed in the nucleus accumbens. This cocaine-induced increase in corticosterone was attenuated by metyrapone/oxazepam. Reducing cocaine-induced increases in corticosterone in the medial prefrontal cortex might represent a novel mechanism through which the combination of metyrapone/oxazepam produces its behavioral effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ibrutinib Therapy Increases T Cell Repertoire Diversity in Patients with Chronic Lymphocytic Leukemia.

PubMed

Yin, Qingsong; Sivina, Mariela; Robins, Harlan; Yusko, Erik; Vignali, Marissa; O'Brien, Susan; Keating, Michael J; Ferrajoli, Alessandra; Estrov, Zeev; Jain, Nitin; Wierda, William G; Burger, Jan A

2017-02-15

The Bruton's tyrosine kinase inhibitor ibrutinib is a highly effective, new targeted therapy for chronic lymphocytic leukemia (CLL) that thwarts leukemia cell survival, growth, and tissue homing. The effects of ibrutinib treatment on the T cell compartment, which is clonally expanded and thought to support the growth of malignant B cells in CLL, are not fully characterized. Using next-generation sequencing technology, we characterized the diversity of TCRβ-chains in peripheral blood T cells from 15 CLL patients before and after 1 y of ibrutinib therapy. We noted elevated CD4 + and CD8 + T cell numbers and a restricted TCRβ repertoire in all pretreatment samples. After 1 y of ibrutinib therapy, elevated peripheral blood T cell numbers and T cell-related cytokine levels had normalized, and T cell repertoire diversity increased significantly. Dominant TCRβ clones in pretreatment samples declined or became undetectable, and the number of productive unique clones increased significantly during ibrutinib therapy, with the emergence of large numbers of low-frequency TCRβ clones. Importantly, broader TCR repertoire diversity was associated with clinical efficacy and lower rates of infections during ibrutinib therapy. These data demonstrate that ibrutinib therapy increases diversification of the T cell compartment in CLL patients, which contributes to cellular immune reconstitution. Copyright © 2017 by The American Association of Immunologists, Inc.

Underestimated effects of sediments on enhanced startup performance of biofilm systems for polluted source water pretreatment.

PubMed

Lv, Zheng-Hui; Wang, Jing; Yang, Guang-Feng; Feng, Li-Juan; Mu, Jun; Zhu, Liang; Xu, Xiang-Yang

2018-02-01

In order to evaluate the enhancement mechanisms of enhanced startup performance in biofilm systems for polluted source water pretreatment, three lab-scale reactors with elastic stereo media (ESM) were operated under different enhanced sediment and hydraulic agitation conditions. It is interesting to found the previously underestimated or overlooked effects of sediment on the enhancement of pollutants removal performance and enrichment of functional bacteria in biofilm systems. The maximum NH 4 + -N removal rate of 0.35 mg L -1 h -1 in sediment enhanced condition was 2.19 times of that in control reactor. Sediment contributed to 42.0-56.5% of NH 4 + -N removal and 15.4-41.2% of total nitrogen removal in different reactors under different operation conditions. The enhanced hydraulic agitation with sediment further improved the operation performance and accumulation of functional bacteria. Generally, Proteobacteria (48.9-52.1%), Bacteroidetes (18.9-20.8%) and Actinobacteria (15.7-18.5%) were dominant in both sediment and ESM bioiflm at  phylum level. The potentially functional bacteria found in sediment and ESM biofilm samples with some functional bacteria mainly presented in sediment samples only (e.g., Genera Bacillus and Lactococcus of Firmicutes phylum) may commonly contribute to the removal of nitrogen and organics.

Ibrutinib therapy increases T cell repertoire diversity in patients with chronic lymphocytic leukemia

PubMed Central

Yin, Qingsong; Sivina, Mariela; Robins, Harlan; Yusko, Erik; Vignali, Marissa; O’Brien, Susan; Keating, Michael J.; Ferrajoli, Alessandra; Estrov, Zeev; Jain, Nitin; Wierda, William G.; Burger, Jan A.

2017-01-01

The BTK inhibitor ibrutinib is a highly effective, new targeted therapy for chronic lymphocytic leukemia (CLL) that thwarts leukemia cell survival, growth, and tissue homing. The effects of ibrutinib treatment on the T cell compartment, which is clonally expanded and thought to support the growth of the malignant B cells in CLL, are not fully characterized. Using next-generation sequencing technology we characterized the diversity of TCRβ chains in peripheral blood T cells from 15 CLL patients before and after one year of ibrutinib therapy. We noted elevated CD4+ and CD8+ T cell numbers and a restricted TCRβ repertoire in all pretreatment samples. After one year of ibrutinib therapy, elevated PB T cell numbers and T-cell related cytokine levels had normalized and T cell repertoire diversity significantly increased. Dominant TCRβ clones in pretreatment samples declined or became undetectable, and the number of productive unique clones significantly increased during ibrutinib therapy, with the emergence of large numbers of low-frequency TCRβ clones. Importantly, broader TCR repertoire diversity was associated with clinical efficacy and lower rates of infections during ibrutinib therapy. These data demonstrate that ibrutinib therapy increases diversification of the T cell compartment in CLL patients, which contributes to cellular immune reconstitution. PMID:28077600

Estimation of cauliflower mass transfer parameters during convective drying

NASA Astrophysics Data System (ADS)

Sahin, Medine; Doymaz, İbrahim

2017-02-01

The study was conducted to evaluate the effect of pre-treatments such as citric acid and hot water blanching and air temperature on drying and rehydration characteristics of cauliflower slices. Experiments were carried out at four different drying air temperatures of 50, 60, 70 and 80 °C with the air velocity of 2.0 m/s. It was observed that drying and rehydration characteristics of cauliflower slices were greatly influenced by air temperature and pre-treatment. Six commonly used mathematical models were evaluated to predict the drying kinetics of cauliflower slices. The Midilli et al. model described the drying behaviour of cauliflower slices at all temperatures better than other models. The values of effective moisture diffusivities ( D eff ) were determined using Fick's law of diffusion and were between 4.09 × 10-9 and 1.88 × 10-8 m2/s. Activation energy was estimated by an Arrhenius type equation and was 23.40, 29.09 and 26.39 kJ/mol for citric acid, blanch and control samples, respectively.

Impact of ozonation and biological activated carbon filtration on ceramic membrane fouling.

PubMed

Ibn Abdul Hamid, Khaled; Sanciolo, Peter; Gray, Stephen; Duke, Mikel; Muthukumaran, Shobha

2017-12-01

Ozone pre-treatment (ozonation, ozonisation) and biological activated carbon (BAC) filtration pre-treatment for the ceramic microfiltration (CMF) treatment of secondary effluent (SE) were studied. Ozone pre-treatment was found to result in higher overall removal of UV absorbance (UVA 254 ) and colour, and higher permeability than BAC pre-treatment or the combined use of ozone and BAC (O3+BAC) pre-treatment. The overall removal of colour and UVA 254 by ceramic filtration of the ozone pre-treated water was 97% and 63% respectively, compared to 86% and 48% respectively for BAC pre-treatment and 29% and 6% respectively for the untreated water. Ozone pre-treatment, however, was not effective in removal of dissolved organic carbon (DOC). The permeability of the ozone pre-treated water through the ceramic membrane was found to decrease to 50% of the original value after 200 min of operation, compared to approximately 10% of the original value for the BAC pre-treated, O3+BAC pre-treated water and the untreated water. The higher permeability of the ozone pre-treated water was attributed to the excellent removal of biopolymer particles (100%) and high removal of humic substances (84%). The inclusion of a BAC stage between ozone pre-treatment and ceramic filtration was detrimental. The O3+BAC+CMF process was found to yield higher biopolymer removal (96%), lower humic substance (HS) component removal (66%) and lower normalized permeability (0.1) after 200 min of operation than the O3+CMF process (86%, 84% and 0.5 respectively). This was tentatively attributed to the chemical oxidation effect of ozone on the BAC biofilm and adsorbed components, leading to the generation of foulants that are not generated in the O3+CMF process. This study demonstrated the potential of ozone pre-treatment for reducing organic fouling and thus improving flux for the CMF of SE compared to O3+BAC pre-treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Lab-on-a-chip based total-phosphorus analysis device utilizing a photocatalytic reaction

NASA Astrophysics Data System (ADS)

Jung, Dong Geon; Jung, Daewoong; Kong, Seong Ho

2018-02-01

A lab-on-a-chip (LOC) device for total phosphorus (TP) analysis was fabricated for water quality monitoring. Many commercially available TP analysis systems used to estimate water quality have good sensitivity and accuracy. However, these systems also have many disadvantages such as bulky size, complex pretreatment processes, and high cost, which limit their application. In particular, conventional TP analysis systems require an indispensable pretreatment step, in which the fluidic analyte is heated to 120 °C for 30 min to release the dissolved phosphate, because many phosphates are soluble in water at a standard temperature and pressure. In addition, this pretreatment process requires elevated pressures of up to 1.1 kg cm-2 in order to prevent the evaporation of the heated analyte. Because of these limiting conditions required by the pretreatment processes used in conventional systems, it is difficult to miniaturize TP analysis systems. In this study, we employed a photocatalytic reaction in the pretreatment process. The reaction was carried out by illuminating a photocatalytic titanium dioxide (TiO2) surface formed in a microfluidic channel with ultraviolet (UV) light. This pretreatment process does not require elevated temperatures and pressures. By applying this simplified, photocatalytic-reaction-based pretreatment process to a TP analysis system, greater degrees of freedom are conferred to the design and fabrication of LOC devices for TP monitoring. The fabricated LOC device presented in this paper was characterized by measuring the TP concentration of an unknown sample, and comparing the results with those measured by a conventional TP analysis system. The TP concentrations of the unknown sample measured by the proposed LOC device and the conventional TP analysis system were 0.018 mgP/25 mL and 0.019 mgP/25 mL, respectively. The experimental results revealed that the proposed LOC device had a performance comparable to the conventional bulky TP analysis system. Therefore, our device could be directly employed in water quality monitoring as an alternative to conventional TP analysis systems.

Epiisopiloturine hydrochloride, an imidazole alkaloid isolated from Pilocarpus microphyllus leaves, protects against naproxen-induced gastrointestinal damage in rats.

PubMed

Nicolau, Lucas A D; Carvalho, Nathalia S; Pacífico, Dvison M; Lucetti, Larisse T; Aragão, Karoline S; Véras, Leiz M C; Souza, Marcellus H L P; Leite, José R S A; Medeiros, Jand Venes R

2017-03-01

This study aimed to investigate the protective effect of epiisopiloturine hydrochloride (EPI), an imidazole alkaloid, on NAP-induced gastrointestinal damage in rats. Initially, rats were pretreated with 0.5% carboxymethylcellulose (vehicle) or EPI (3, 10 and 30mg/kg, p.o. or i.p., groups 3-5, respectively) twice daily, for 2days. After 1h, NAP (80mg/kg, p.o.) was given. The control group received only vehicle (group 1) or vehicle+naproxen (group 2). Rats were euthanized on 2nd day, 4h after NAP treatment. Stomachs lesions were measured. Samples were collected for histological evaluation and glutathione (GSH), malonyldialdehyde (MDA), myeloperoxidase (MPO), and cytokines levels. Moreover, gastric mucosal blood flow (GMBF) was evaluated. EPI pretreatment prevented NAP-induced macro and microscopic gastric damage with a maximal effect at 10mg/kg. Histological analysis revealed that EPI decreased scores of damage caused by NAP. EPI reduced MPO (3.4±0.3U/mg of gastric tissue) and inhibited changes in MDA (70.4±8.3mg/g of gastric tissue) and GSH (246.2±26.4mg/g of gastric tissue). NAP increased TNF-α levels, and this effect was reduced by EPI pretreatment. Furthermore, EPI increased GMBF by 15% compared with the control group. Our data show that EPI protects against NAP-induced gastric and intestinal damage by reducing pro-inflammatory cytokines, reducing oxidative stress, and increasing GMBF. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Effect of organic compositions of aerobically pretreated municipal solid waste on non-methane organic compound emissions during anaerobic degradation.

PubMed

Zhang, Yuanyuan; Yue, Dongbei; Liu, Jianguo; He, Liang; Nie, Yongfeng

2012-06-01

Odor pollution caused by municipal solid waste (MSW) treatment plants has become a growing public concern. Although aerobic pretreatment of MSW has advantages in accelerating landfill stabilization, the property of non-methane organic compound (NMOC) emissions from aerobically pretreated MSW (APMSW) during landfilling is unknown. To investigate NMOC emissions from anaerobic degradation of APMSW and to study the impact of organic compositions of APMSW and their decomposition stages, five simulative anaerobic bioreactors (R1-R5) were filled up with APMSW of different original organic compositions in a laboratory. For NMOC analysis, samples were collected from the gas that accumulated separately during two successive independent stages of the whole experiment. The results showed that the cumulative quantities of NMOCs from R1 to R5 were 1.11, 0.30, 0.18, 0.28, and 0.31 mg/kg DM, respectively, when volatile solid was degraded by 34.8-47.2%. As the organic content of the original waste was lower, the proportion of NMOCs generated in the early stage of anaerobic degradation became higher. Multiple linear regression analyses of the relationship between the quantities of degraded organics and generated NMOCs showed that lipid and protein have a strong effect on NMOC amount. The effect of lipid on NMOC quantity lasts longer than that of protein. This observation suggests that controlling the lipid and protein contents in MSW can reduce the odor from landfills. Copyright © 2012 Elsevier Ltd. All rights reserved.

Protection against diisopropylfluorophosphate intoxication by pyridostigmine and physostigmine in combination with atropine and mecamylamine.

PubMed

Harris, L; Stitcher, D

1984-08-01

Atropine (A), mecamylamine (M), pyridostigmine (Py) and physostigmine (Ph) are pretreatment components of Mix I (A = 0.79, M = 0.79, Py = 0.056 mg/kg) and Mix II (A = 0.79, M = 0.79, Ph = 0.026 mg/kg). They have been successfully used in antagonizing Soman intoxication in experimental animals. Rats were pretreated with either Mix I or Mix II and subsequently exposed to diisopropylfluorphosphate (DFP). Pretreatment with Mix I or Mix II (i.m.) 30 min before DFP (i.v.) protected rats from the lethal effects of DFP. The protective ratios were 2.8 (Mix I) and 6.9 (Mix II). Changes in brain levels of acetylcholine (ACh) were measured to help understand the basis for effectiveness of these pretreatments. In the absence of DFP, pretreatments had no significant (P greater than 0.05) effect on bound or free ACh. Pretreatment did not prevent the DFP-induced rise in bound and free ACh nor the agent-induced physical incapacitation at 30 min post exposure. At 2 h after DFP exposure, rats pretreated with Mix II, but not Mix I, showed significant recovery from signs of physical incapacitation. At 30 min after the administration of 3.3 mg/kg of DFP (i.v.), the levels of free and bound ACh in rats given Mix I or Mix II pretreatment increased above control levels by 705% and 116% and 120% and 43%, respectively. By 2 h after DFP, cerebral ACh levels had changed to 437% and 91% with Mix I pretreatment and 26% and 50% with Mix II pretreatment. These data suggest a correlation between DFP-induced increases in the levels of cerebral ACh, possibly free, and physical incapacitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of physical interventions on house dust mite allergen levels in carpet, bed, and upholstery dust in low-income, urban homes.

PubMed Central

Vojta, P J; Randels, S P; Stout, J; Muilenberg, M; Burge, H A; Lynn, H; Mitchell, H; O'Connor, G T; Zeldin, D C

2001-01-01

House dust mite allergen exposure is a postulated risk factor for allergic sensitization, asthma development, and asthma morbidity; however, practical and effective methods to mitigate these allergens from low-income, urban home environments remain elusive. The purpose of this study was to assess the feasibility and effectiveness of physical interventions to mitigate house dust mite allergens in this setting. Homes with high levels of house dust mite allergen (Der f 1 + Der p 1 > or = 10 microg/g dust by enzyme-linked immunosorbent assay) in the bed, bedroom carpet, and/or upholstered furniture were enrolled in the study. Carpets and upholstered furniture were subjected to a single treatment of either dry steam cleaning plus vacuuming (carpet only) or intensive vacuuming alone. Bed interventions consisted of complete encasement of the mattress, box spring, and pillows plus either weekly professional or in-home laundering of nonencased bedding. Dust samples were collected at baseline and again at 3 days (carpet and upholstery only) and 2, 4, and 8 weeks posttreatment. We compared pretreatment mean allergen concentrations and loads to posttreatment values and performed between-group analyses after adjusting for differences in the pretreatment means. Both dry steam cleaning plus vacuuming and vacuuming alone resulted in a significant reduction in carpet house dust mite allergen concentration and load (p < 0.05). Levels approached pretreatment values by 4 weeks posttreatment in the intensive vacuuming group, whereas steam cleaning plus vacuuming effected a decrease that persisted for up to 8 weeks. Significant decreases in bed house dust mite allergen concentration and load were obtained in response to encasement and either professional or in-home laundering (p < 0.001). Between-group analysis revealed significantly less postintervention house dust mite allergen load in professionally laundered compared to home-laundered beds (p < 0.05). Intensive vacuuming and dry steam cleaning both caused a significant reduction in allergen concentration and load in upholstered furniture samples (p < 0.005). Based on these data, we conclude that physical interventions offer practical, effective means of reducing house dust mite allergen levels in low-income, urban home environments. PMID:11564617

Evaluation of agave bagasse recalcitrance using AFEX™, autohydrolysis, and ionic liquid pretreatments.

PubMed

Perez-Pimienta, Jose A; Flores-Gómez, Carlos A; Ruiz, Héctor A; Sathitsuksanoh, Noppadon; Balan, Venkatesh; da Costa Sousa, Leonardo; Dale, Bruce E; Singh, Seema; Simmons, Blake A

2016-07-01

A comparative analysis of the response of agave bagasse (AGB) to pretreatment by ammonia fiber expansion (AFEX™), autohydrolysis (AH) and ionic liquid (IL) was performed using 2D nuclear magnetic resonance (NMR) spectroscopy, wet chemistry, enzymatic saccharification and mass balances. It has been found that AFEX pretreatment preserved all carbohydrates in the biomass, whereas AH removed 62.4% of xylan and IL extracted 25% of lignin into wash streams. Syringyl and guaiacyl lignin ratio of untreated AGB was 4.3, whereas for the pretreated biomass the ratios were 4.2, 5.0 and 4.7 for AFEX, AH and IL, respectively. Using NMR spectra, the intensity of β-aryl ether units in aliphatic, anomeric, and aromatic regions decreased in all three pretreated samples when compared to untreated biomass. Yields of glucose plus xylose in the major hydrolysate stream were 42.5, 39.7 and 26.9kg per 100kg of untreated AGB for AFEX, IL and AH, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enhanced hydrolysis and methane yield by applying microaeration pretreatment to the anaerobic co-digestion of brown water and food waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lim, Jun Wei; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798; Wang, Jing-Yuan, E-mail: jywang@ntu.edu.sg

2013-04-15

Highlights: ► Microaeration pretreatment was effective for brown water and food waste mixture. ► The added oxygen was consumed fully by facultative microorganisms. ► Enhanced solubilization, acidification and breakdown of SCFAs to acetate. ► Microaeration pretreatment improved methane yield by 10–21%. ► Nature of inoculum influenced the effects of microaeration. - Abstract: Microaeration has been used conventionally for the desulphurization of biogas, and recently it was shown to be an alternative pretreatment to enhance hydrolysis of the anaerobic digestion (AD) process. Previous studies on microaeration pretreatment were limited to the study of substrates with complex organic matter, while little hasmore » been reported on its effect on substrates with higher biodegradability such as brown water and food waste. Due to the lack of consistent microaeration intensities, previous studies were not comparable and thus inconclusive in proving the effectiveness of microaeration to the overall AD process. In this study, the role of microaeration pretreatment in the anaerobic co-digestion of brown water and food waste was evaluated in batch-tests. After a 4-day pretreatment with 37.5 mL-O{sub 2}/L{sub R}-d added to the liquid phase of the reactor, the methane production of substrates were monitored in anaerobic conditions over the next 40 days. The added oxygen was consumed fully by facultative microorganisms and a reducing environment for organic matter degradation was maintained. Other than higher COD solubilization, microaeration pretreatment led to greater VFA accumulation and the conversion of other short chain fatty acids to acetate. This could be due to enhanced activities of hydrolytic and acidogenic bacteria and the degradation of slowly biodegradable compounds under microaerobic conditions. This study also found that the nature of inoculum influenced the effects of microaeration as a 21% and 10% increase in methane yield was observed when pretreatment was applied to inoculated substrates, and substrates without inoculum, respectively.« less

Tackling bioactive glass excessive in vitro bioreactivity: Preconditioning approaches for cell culture tests.

PubMed

Ciraldo, Francesca E; Boccardi, Elena; Melli, Virginia; Westhauser, Fabian; Boccaccini, Aldo R

2018-05-21

Bioactive glasses (BGs) are being increasingly considered for biomedical applications in bone and soft tissue replacement approaches thanks to their ability to form strong bonding with tissues. However, due to their high reactivity once in contact with water-based solutions BGs rapidly exchange ions with the surrounding environment leading in most cases to an undesired increase of the pH under static in vitro conditions (due to alkaline ion "burst release"), making difficult or even impossible to perform cell culture studies. Several pre-conditioning treatments have been therefore proposed in laboratories worldwide to limit this problem. This paper presents an overview of the different strategies that have been put forward to pre-treat BG samples to tackle the pH raise issue in order to enable cell biology studies. The paper also discusses the relevant criteria that determine the selection of the optimal pre-treatment depending on the BG composition and morphology (e.g. particles, scaffolds). Bioactive glasses (BGs), since their discovery in 1971 by L.L Hench, have been widely used for bone replacement and repair, and, more recently, they are becoming highly attractive for bone and soft tissue engineering applications. BGs have in fact the ability to form a strong bond with both hard and soft tissues once in contact with biological fluid. The enhanced interaction of BGs with the biological environment is based on their significant surface bioreactivity. This surface effect of BGs is, on the other hand, problematic for cell biology studies by standard (static) cell culture methods: an excessive bioreactivity leads in most cases to a rapid and dramatic increase of the pH of the surrounding medium, which results in cell death and makes cell culture tests on BG samples impossible. The BG research community has been aware of this for many years and numerous pre-treatments have been proposed by different groups worldwide to limit this problem. For the first time, we have reviewed in this paper the variety of surface preconditioning treatments that have been put forward over the years, we provide a summary of such pre-treatments used in laboratory practice, discussing and offering criteria that can be used for the determination of the optimal pre-treatment depending on BG composition and morphology of the sample tested (bulk, particulate, scaffolds). The information and discussion provided in this review should support best research practice when testing bioactive glasses in cell culture. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Hazardous Alcohol Drinking as Predictor of Smoking Relapse (3-, 6-, and 12-Months Follow-Up) by Gender.

PubMed

Rodríguez-Cano, Rubén; López-Durán, Ana; Martínez-Vispo, Carmela; Martínez, Úrsula; Fernández Del Río, Elena; Becoña, Elisardo

2016-12-01

Diverse studies have found a relation between alcohol consumption and smoking relapse. Few studies have analyzed the relation of smoking relapse with pretreatment alcohol consumption and gender differences. The main purpose of this study is to analyze the influence of alcohol consumption in smoking relapse over 12 months (3-, 6-, and 12-months follow-up) and to determine possible gender differences. The sample included 374 smokers who quit smoking by participating in a psychological smoking cessation treatment. We assessed hazardous pretreatment alcohol drinking (AUDIT), cigarette consumption (FTND; number of cigarettes) and sociodemographic variables. Higher scores on hazardous pretreatment alcohol drinking predict smoking relapse at 3-, 6-, and 12-months after smoking cessation. In males, higher scores on hazardous pretreatment alcohol drinking predict relapse at 6 and at 12 months. In females, higher scores on hazardous pretreatment alcohol drinking predict tobacco relapse at 3 months. Hazardous pretreatment alcohol drinking predicts relapse at all intervals after smoking cessation (3-, 6-, and 12-months follow-up). However, the influence of hazardous pretreatment alcohol drinking on smoking relapse differs as a function of gender, as it is a short-term predictor in women (3 months) and a long-term predictor in men (6 and 12 months). Copyright © 2016 Elsevier Inc. All rights reserved.

Prognostic significance of the lymphocyte-to-monocyte ratio in patients with metastatic colorectal cancer.

PubMed

Shibutani, Masatsune; Maeda, Kiyoshi; Nagahara, Hisashi; Ohtani, Hiroshi; Sakurai, Katsunobu; Yamazoe, Sadaaki; Kimura, Kenjiro; Toyokawa, Takahiro; Amano, Ryosuke; Tanaka, Hiroaki; Muguruma, Kazuya; Hirakawa, Kosei

2015-09-14

To evaluate the prognostic significance of the lymphocyte to monocyte ratio (LMR) in patients with unresectable metastatic colorectal cancer who received palliative chemotherapy. A total of 104 patients with unresectable metastatic colorectal cancer who underwent palliative chemotherapy were enrolled. The LMR was calculated from blood samples by dividing the absolute lymphocyte count by the absolute monocyte count. Pre-treatment LMR values were measured within one week before the initiation of chemotherapy, while post-treatment LMR values were measured eight weeks after the initiation of chemotherapy. The median pre-treatment LMR was 4.16 (range: 0.58-14.06). We set 3.38 as the cut-off level based on the receiver operating characteristic curve. Based on the cut-off level of 3.38, 66 patients were classified into the high pre-treatment LMR group and 38 patients were classified into the low pre-treatment LMR group. The low pre-treatment LMR group had a significantly worse overall survival rate (P = 0.0011). Moreover, patients who demonstrated low pre-treatment LMR and normalization after treatment exhibited a better overall survival rate than the patients with low pre-treatment and post-treatment LMR values. The lymphocyte to monocyte ratio is a useful prognostic marker in patients with unresectable metastatic colorectal cancer who receive palliative chemotherapy.

Skin Pretreatment With Conventional Non-Fractional Ablative Lasers Promote the Transdermal Delivery of Tranexamic Acid.

PubMed

Hsiao, Chien-Yu; Sung, Hsin-Ching; Hu, Sindy; Huang, Chun-Hsun

2016-07-01

Laser pretreatment of skin can be used to enable drugs used in dermatology to penetrate the skin to the depth necessary for their effect to take place. To compare the permeation of tranexamic acid after conventional non-fractionated ablative Er:YAG and CO2 laser pretreatment in a laser-aided transdermal delivery system. An erbium-doped yttrium aluminium garnet (Er:YAG) and a CO2 laser were used to pretreat dorsal porcine skin. Scanning electron microscopy was used to examine disruption of the skin surface. Confocal laser scanning microscopy was used to determine the depth of penetration of a reporter molecule (fluorescein isothiocyanate) into the skin. A Franz diffusion assembly was used to examine fluency-related increases in transdermal delivery of transexamic acid. Transdermal delivery of tranexamic acid increased as Er:YAG laser fluency increased. Transdermal delivery was higher when CO2 laser pretreatment was used than when Er:YAG laser pretreatment was used, but a "ceiling effect" was present and increasing the wattage did not cause a further increase in delivery. CO2 laser pretreatment also caused more extensive and deeper skin disruption than Er:YAG laser pretreatment. For conventional, non-fractionated ablative laser pretreatment, the Er:YAG laser would be an optimal choice to enhance transdermal penetration of transexamic acid.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gabhane, Jagdish; William, S.P.M. Prince, E-mail: spmp_william@neeri.res.in; Vaidya, Atul N.

Highlights: • SAAP is an efficient and economic means of pretreatment. • SAAP was found to be efficient in lignin and hemicellulose removal. • SAAP enhanced the enzymatic hydrolysis. • FTIR, XRD and SEM provided vivid understanding about the mode of action of SAAP. • Mass balance closer of 98% for pretreated GB confirmed the reliability of SAAP. - Abstract: A comprehensive study was carried out to assess the effectiveness of solar assisted alkali pretreatment (SAAP) on garden biomass (GB). The pretreatment efficiency was assessed based on lignocellulose degradation, conversion of cellulose into reducing sugars, changes in the ultra-structure andmore » functional groups of lignocellulose and impact on the crystallinity of cellulose, etc. SAAP was found to be efficient for the removal of lignin and hemicellulose that facilitated enzymatic hydrolysis of cellulose. FTIR and XRD studies provided details on the effectiveness of SAAP on lignocellulosic moiety and crystallinity of cellulose. Scanning electron microscopic analysis showed ultra-structural disturbances in the microfibrils of GB as a result of pretreatment. The mass balance closer of 97.87% after pretreatment confirmed the reliability of SAAP pretreatment. Based on the results, it is concluded that SAAP is not only an efficient means of pretreatment but also economical as it involved no energy expenditure for heat generation during pretreatment.« less

Use of lactic acid with electron beam irradiation for control of Escherichia coli O157:H7, non-O157 VTEC E. coli, and Salmonella serovars on fresh and frozen beef.

PubMed

Li, Shuliu; Kundu, Devapriya; Holley, Richard A

2015-04-01

Lactic acid pre-treatment was examined to enhance the antimicrobial action of electron (e-) beam irradiation of beef trim. Meat samples were inoculated with Escherichia coli O157:H7, non-O157 VTEC E. coli or Salmonella cocktails and treated with 5% lactic acid at 55 °C. Samples were packaged aerobically or vacuum-packed, kept at 4 °C and treated with 1 kGy e-beam energy. Frozen samples were treated with 1, 3 or 7 kGy and stored at -20 °C for ≤ 5 d. Lactic acid enhanced the antimicrobial action of 1 kGy e-beam treatment against Salmonella by causing an additional <1.8 log CFU/g reduction. One kGy treatment of refrigerated samples reduced VTEC E. coli viability by 4.5 log CFU/g, and while lactic acid did not improve the reduction, after freezing additive effects were found. After 3 kGy irradiation, Salmonella was reduced by 2 and 4 log CFU/g in the irradiated and lactic acid plus irradiated samples, respectively. Lactic acid pre-treatment was of limited value with 1 kGy treatment for improving control of toxigenic E. coli in fresh beef trim, however, it would be useful with low dose irradiation for controlling both VTEC E. coli and Salmonella in frozen product. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of different freezing methods on calcium enriched papaya (Carica papaya L.).

PubMed

Lovera, Nancy N; Ramallo, Laura; Salvadori, Viviana O

2018-06-01

The effect of calcium impregnation on drip loss, colour, mechanical properties, sensory perception and freezing time on frozen-thawed papaya was studied, evaluating different freezing methods: cryogenic, tunnel and household freezer freezing. Osmotic dehydration as pre-treatment was also evaluated. Freezing in liquid nitrogen was considered an inappropriate method for papaya preservation due to cracking. Calcium impregnation and osmotic dehydration increased tissue firmness and decreased freezing time (freezing time for fresh, calcium impregnated and osmo-dehydrated fruit was 23, 17 and 5 min in a tunnel and 118, 83 and 60 min in a household freezer, respectively). Calcium lactate was the most effective way to protect tissue's firmness before and after a freeze-thaw cycle (maximum stress values approx. 300-400% of the raw tissue for tunnel freezing and 260% for household freezer). Microstructure analysis showed better tissue integrity retention in papaya samples impregnated with calcium lactate than in those with calcium gluconate, after a freezing-thawing cycle, in agreement with the drip loss results. In spite of these results, consumers preferred frozen papaya without pre-treatment or impregnated with calcium gluconate.

Enhancement of gold recovery using bioleaching from gold concentrate

NASA Astrophysics Data System (ADS)

Choi, S. H.; Cho, K. H.; Kim, B. J.; Choi, N. C.; Park, C. Y.

2012-04-01

The gold in refractory ores is encapsulated as fine particles (sometimes at a molecular level) in the crystal structure of the sulfide (typically pyrite with or without arsenopyrite) matrix. This makes it impossible to extract a significant amount of refractory gold by cyanidation since the cyanide solution cannot penetrate the pyrite/arsenopyrite crystals and dissolve gold particles, even after fine grinding. To effectively extract gold from these ores, an oxidative pretreatment is necessary to break down the sulfide matrix. The most popular methods of pretreatment include nitric acid oxidation, roasting, pressure oxidation and biological oxidation by microorganisms. This study investigated the bioleaching efficiency of Au concentrate under batch experimental conditions (adaptation cycles and chemical composition adaptation) using the indigenous acidophilic bacteria collected from gold mine leachate in Sunsin gold mine, Korea. We conducted the batch experiments at two different chemical composition (CuSO4 and ZnSO4), two different adaptation cycles 1'st (3 weeks) and 2'nd (6 weeks). The results showed that the pH in the bacteria inoculating sample decreased than initial condition and Eh increased. In the chemical composition adaptation case, the leached accumulation content of Fe and Pb was exhibited in CuSO4 adaptation bacteria sample more than in ZnSO4 adaptation bacteria samples, possibly due to pre-adaptation effect on chalcopyrite (CuFeS2) in gold concentrate. And after 21 days on the CuSO4 adaptation cycles case, content of Fe and Pb was appeared at 1'st adaptation bacteria sample(Fe - 1.82 and Pb - 25.81 times per control sample) lower than at 2'nd adaptation bacteria sample(Fe - 2.87 and Pb - 62.05 times per control sample). This study indicates that adaptation chemical composition and adaptation cycles can play an important role in bioleaching of gold concentrate in eco-/economic metallurgy process.

Effect of pretreatment on purple-fleshed sweet potato flour for cake making

NASA Astrophysics Data System (ADS)

Hutasoit, M. S.; Julianti, E.; Lubis, Z.

2018-02-01

The purple-fleshed sweet-potato (PFSP) flour was produced by varying pretreatment of washed chips: dipping in 0.5 and 1.0% (w/v) citric acid solution for 30 min, dipping in 0.5 and 1.0% (w/v) citric acid solution for 30 min and followed by steam blanching for 5 min. The pretreatment effect on cake quality was investigated. The results showed that PFSP flour produced from pretreatment with dipping in 0.5% citric acid for 30 min followed by steam blanching for 5 min had higher lightness (L*) value and lower browning index, higher hedonic value of color and aroma and baking expansion. The specific volume of cake from pretreated flour, untreated flour and wheat flour were 44.87, 43.83, and 50.43cm3/g, respectively. The sensory evaluation of cake indicated that cake from pretreated PFSP flour was acceptable compare to those of cake from wheat flour.

Effects of microwave and alkali induced pretreatment on sludge solubilization and subsequent aerobic digestion.

PubMed

Chang, Chia-Jung; Tyagi, Vinay Kumar; Lo, Shang-Lien

2011-09-01

Individual and combined effects of microwave (MW) and alkali pretreatments on sludge disintegration and subsequent aerobic digestion of waste activated sludge (WAS) were studied. Pretreatments with MW (600W-85°C-2 min), conventional heating (520 W-80°C-12 min) and alkali (1.5 g NaOH/L - pH 12-30 min) achieved 8.5%, 7% and 18% COD solubilization, respectively. However, combined MW-alkali pretreatment synergistically enhanced sludge solubilization and achieved 46% COD solubilization, 20% greater than the additive value of MW alone and alkali alone (8.5+18%=26.5%). Moreover, the results of the batch aerobic digestion study on MW-alkali pretreated sludge showed 93% and 63% reductions in SCOD and VSS concentrations, respectively, at 16 days of SRT. The VSS reduction was 20% higher than that of WAS without pretreatment. Copyright © 2011 Elsevier Ltd. All rights reserved.

Improvement of the conductive network of positive electrodes and the performance of Ni-MH battery

NASA Astrophysics Data System (ADS)

Morimoto, Katsuya; Nakayama, Kousuke; Maki, Hideshi; Inoue, Hiroshi; Mizuhata, Minoru

2017-06-01

The pretreatment to modify the valence of cobalt by discharging at 0.2 C rate for 7.5 h before the first initial activation charge process is effective in improving the surface electronic conductivity among fine particles of positive electrode active materials. The discharge curves indicate the same locus within 1800 cycles, and the capacity of the pretreated battery is stable for over 4000 cycles. However, in-situ cell pretreatment with constant current has negative influence on other components. During the constant current pretreatment, the cell voltage rapidly falls to -0.5 V in the first 10 s of in-situ pretreatment. Therefore, we investigate the pretreatment by supplying a constant voltage to the battery instead of a constant current, and find the effective condition to improve the electrochemical performance and not to have any influence on other components of the battery.

Pretreatment of Cellulose By Electron Beam Irradiation Method

NASA Astrophysics Data System (ADS)

Jusri, N. A. A.; Azizan, A.; Ibrahim, N.; Salleh, R. Mohd; Rahman, M. F. Abd

2018-05-01

Pretreatment process of lignocellulosic biomass (LCB) to produce biofuel has been conducted by using various methods including physical, chemical, physicochemical as well as biological. The conversion of bioethanol process typically involves several steps which consist of pretreatment, hydrolysis, fermentation and separation. In this project, microcrystalline cellulose (MCC) was used in replacement of LCB since cellulose has the highest content of LCB for the purpose of investigating the effectiveness of new pretreatment method using radiation technology. Irradiation with different doses (100 kGy to 1000 kGy) was conducted by using electron beam accelerator equipment at Agensi Nuklear Malaysia. Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction (XRD) analyses were studied to further understand the effect of the suggested pretreatment step to the content of MCC. Through this method namely IRR-LCB, an ideal and optimal condition for pretreatment prior to the production of biofuel by using LCB may be introduced.

The effect of H2O and pretreatment on the activity of a Pt/SnO2 catalyst

NASA Technical Reports Server (NTRS)

Vannorman, John D.; Brown, Kenneth G.; Schryer, Jacqueline; Schryer, David R.; Upchurch, Billy T.; Sidney, Barry D.

1990-01-01

CO oxidation catalysts with high activity at 25 C to 100 C are important for long-life, closed-cycle operation of pulsed CO2 lasers. A reductive pretreatment with either CO or H2 has been shown to significantly enhance the activity of a commercially available platinum on tin (IV) oxide (Pt/SnO2) catalyst relative to an oxidative or inert pretreatment or no pretreatment. Pretreatment at temperatures of 175 C and above causes an initial dip in the observed CO2 yield before the steady-state yield is attained. This dip has been found to be caused by dehydration of the catalyst during pretreatment and is readily eliminated by humidifying the catalyst or the reaction gas mixture. It is hypothesized that the effect of humidification is to increase the concentration of OH groups on the catalyst surface which play a role in the reaction mechanism.

The effects of pretreatment conditions on a Pt/SnO2 catalyst for the oxidation of CO in CO2 lasers

NASA Technical Reports Server (NTRS)

Schryer, David R.; Vannorman, John D.; Brown, Kenneth G.; Schryer, Jacqueline

1989-01-01

CO oxidation catalysts with high activity at 25 to 100 C are important for long life, closed cycle operation of pulsed CO2 lasers. A reductive pretreatment with either CO or H2 was shown to significantly enhance the activity of a commercially available platinum on tin (IV) oxide (Pt/SnO2) catalyst relative to an oxidative or inert pretreatment of no pretreatment. Pretreatment at temperatures of 175 C and above causes an initial dip in the observed CO2 yield before the steady state yield is attained. This dip was found to be caused by dehydration of the catalyst during pretreatment and is readily eliminated by humidifying the catalyst or the reaction gas mixture. It is hypothesized that the effect of humidification is to increase the concentration of OH groups on the catalyst surface which play a role in the reaction mechanism.

Steam explosion pretreatment for enhancing biogas production of late harvested hay.

PubMed

Bauer, Alexander; Lizasoain, Javier; Theuretzbacher, Franz; Agger, Jane W; Rincón, María; Menardo, Simona; Saylor, Molly K; Enguídanos, Ramón; Nielsen, Paal J; Potthast, Antje; Zweckmair, Thomas; Gronauer, Andreas; Horn, Svein J

2014-08-01

Grasslands are often abandoned due to lack of profitability. Extensively cultivating grassland for utilization in a biogas-based biorefinery concept could mend this problem. Efficient bioconversion of this lignocellulosic biomass requires a pretreatment step. In this study the effect of different steam explosion conditions on hay digestibility have been investigated. Increasing severity in the pretreatment induced degradation of the hemicellulose, which at the same time led to the production of inhibitors and formation of pseudo-lignin. Enzymatic hydrolysis showed that the maximum glucose yields were obtained under pretreatment at 220 °C for 15 min, while higher xylose yields were obtained at 175 °C for 10 min. Pretreatment of hay by steam explosion enhanced 15.9% the methane yield in comparison to the untreated hay. Results indicate that hay can be effectively converted to methane after steam explosion pretreatment. Copyright © 2014 Elsevier Ltd. All rights reserved.

The effect of liquid hot water pretreatment on the chemical–structural alteration and the reduced recalcitrance in poplar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Mi; Cao, Shilin; Meng, Xianzhi

Hydrothermal pretreatment using liquid hot water (LHW) is capable of substantially reducing the cell wall recalcitrance of lignocellulosic biomass. It enhances the saccharification of polysaccharides, particularly cellulose, into glucose with relatively low capital required. Due to the close association with biomass recalcitrance, the structural change of the components of lignocellulosic materials during the pretreatment is crucial to understand pretreatment chemistry and advance the bio-economy. Although the LHW pretreatment has been extensively applied and studied, the molecular structural alteration during pretreatment and its significance to reduced recalcitrance have not been well understood.

The effect of liquid hot water pretreatment on the chemical–structural alteration and the reduced recalcitrance in poplar

DOE PAGES

Li, Mi; Cao, Shilin; Meng, Xianzhi; ...

2017-11-30

Hydrothermal pretreatment using liquid hot water (LHW) is capable of substantially reducing the cell wall recalcitrance of lignocellulosic biomass. It enhances the saccharification of polysaccharides, particularly cellulose, into glucose with relatively low capital required. Due to the close association with biomass recalcitrance, the structural change of the components of lignocellulosic materials during the pretreatment is crucial to understand pretreatment chemistry and advance the bio-economy. Although the LHW pretreatment has been extensively applied and studied, the molecular structural alteration during pretreatment and its significance to reduced recalcitrance have not been well understood.

Protective effect of preconditioning and adenosine pretreatment in experimental skeletal muscle reperfusion injury.

PubMed

Papanastasiou, S; Estdale, S E; Homer-Vanniasinkam, S; Mathie, R T

1999-07-01

Prolonged ischaemia followed by reperfusion (I/R) of skeletal muscle results in significant tissue injury. Ischaemic preconditioning (IPC), achieved by repeated brief periods of I/R before prolonged ischaemia or adenosine pretreatment, can prevent I/R injury in cardiac muscle. The aim of this study was to ascertain in a rodent model if damage to skeletal muscle due to global hindlimb tourniquet-induced I/R could be similarly attenuated. Anaesthetized rats were randomized (n = 6-10 per group) to five groups: sham-operated controls; I/R (4 h of ischaemia, 2 h of reperfusion); IPC (three cycles of 10 min of ischaemia/10 min of reperfusion) alone; IPC immediately preceding I/R; or adenosine 1000 microg/kg immediately before I/R. At the end of reperfusion, biopsies were taken from the left gastrocnemius muscle for measurement of myeloperoxidase (MPO) and reduced glutathione (GSH). Before ischaemia and at the end of reperfusion, blood samples were taken for measurement of nitric oxide metabolites, tumour necrosis factor (TNF) alpha and macrophage inflammatory protein (MIP) 2. IPC before I/R resulted in lower levels of MPO (P < 0.001) and TNF-alpha (P = 0.004), and higher levels of GSH (P < 0.001) and nitric oxide metabolites (P = 0.002) than I/R alone. Adenosine had effects comparable to IPC pretreatment (P < 0.001 for MPO, P = 0.002 for GSH, P = 0.02 for nitric oxide metabolites and P = 0.001 for TNF-alpha). There was no difference in the blood pressure or the MIP-2 concentration among the groups. IPC or pretreatment with adenosine ameliorates the I/R injury of skeletal muscle.

Rice Husk Ash to Stabilize Heavy Metals Contained in Municipal Solid Waste Incineration Fly Ash: First Results by Applying New Pre-treatment Technology

PubMed Central

Benassi, Laura; Franchi, Federica; Catina, Daniele; Cioffi, Flavio; Rodella, Nicola; Borgese, Laura; Pasquali, Michela; Depero, Laura E.; Bontempi, Elza

2015-01-01

A new technology was recently developed for municipal solid waste incineration (MSWI) fly ash stabilization, based on the employment of all waste and byproduct materials. In particular, the proposed method is based on the use of amorphous silica contained in rice husk ash (RHA), an agricultural byproduct material (COSMOS-RICE project). The obtained final inert can be applied in several applications to produce “green composites”. In this work, for the first time, a process for pre-treatment of rice husk, before its use in the stabilization of heavy metals, based on the employment of Instant Pressure Drop technology (DIC) was tested. The aim of this work is to verify the influence of the pre-treatment on the efficiency on heavy metals stabilization in the COSMOS-RICE technology. DIC technique is based on a thermomechanical effect induced by an abrupt transition from high steam pressure to a vacuum, to produce changes in the material. Two different DIC pre-treatments were selected and thermal annealing at different temperatures were performed on rice husk. The resulting RHAs were employed to obtain COSMOS-RICE samples, and the stabilization procedure was tested on the MSWI fly ash. In the frame of this work, some thermal treatments were also realized in O2-limiting conditions, to test the effect of charcoal obtained from RHA on the stabilization procedure. The results of this work show that the application of DIC technology into existing treatment cycles of some waste materials should be investigated in more details to offer the possibility to stabilize and reuse waste. PMID:28793605

Enzymatic Hydrolysis of Pretreated Fibre Pressed Oil Palm Frond by using Sacchariseb C6

NASA Astrophysics Data System (ADS)

Hashim, F. S.; Yussof, H. W.; Zahari, M. A. K. M.; Rahman, R. A.; Illias, R. M.

2017-06-01

Enzymatic hydrolysis becomes a prominent technology for conversion of cellulosic biomass to its glucose monomers that requires an action of cellulolytic enzymes in a sequential and synergistic manner. In this study, the effect of agitation speed, glucan loading, enzyme loading, temperature and reaction time on the production of glucose from fibre pressed oil palm frond (FPOPF) during enzymatic hydrolysis was screened by a half factorial design 25-1 using Response Surface Methodology (RSM). The FPOPF sample was first delignified by alkaline pretreatment at 4.42 (w/v) sodium hydroxide for an hour prior to enzymatic hydrolysis using commercial cellulase enzyme, Sacchariseb C6. The effect of enzymatic hydrolysis on the structural of FPOPF has been evaluated by Scanning Electron Microscopy (SEM) analysis. Characterization of raw FPOPF comprised of 4.5 extractives, 40.7 glucan, 26.1 xylan, 26.2 lignin and 1.8 ash, whereas for pretreated FPOPF gave 0.3 extractives, 61.4 glucan, 20.4 xylan, 13.3 lignin and 1.3 ash. From this study, it was found that the best enzymatic hydrolysis condition yielded 33.01 ± 0.73 g/L of glucose when performed at 200 rpm of agitation speed, 60 FPU/mL of enzyme loading, 4 (w/w) of glucan loading, temperature at 55 □ and 72 hours of reaction time. The model obtained was significant with p-value <0.0001 as verified by the analysis of variance (ANOVA). The coefficient of determination (R2) from ANOVA study was 0.9959. Overall, it can be concluded that addition of Sacchariseb C6 during enzymatic hydrolysis from pretreated FPOPF produce high amount of glucose that enhances it potential for industrial application. This glucose can be further used to produce high-value products.

Psychopharmacological investigation of the monoamine oxidase inhibitory activity of molindone, a dihydroindolone neuroleptic.

PubMed

Balsara, J J; Gada, V P; Nandal, N V; Chandorkar, A G

1984-09-01

24 h pretreatment with molindone enhanced the behavioural effects of L-dopa and 5-HTP, precursors of biogenic amines (catecholamines and 5-HT respectively) preferentially deaminated by MAO-A, confirming that a metabolite of molindone inhibits MAO-A. 24 h pretreatment with molindone enhanced the behavioural effects of tryptamine and antagonized reserpine-induced ptosis, and in molindone-pretreated rats L-tryptophan induced behavioural effects, probably because of the MAO-A inhibitory activity exerted by a metabolite of molindone. Since 24 h pretreatment with molindone, unlike 30 min pretreatment with clomipramine, failed to antagonize fenfluramine and p-chloramphetamine-induced behavioural syndromes, it suggests that molindone and/or its metabolites most probably do not exert 5-HT neuronal uptake blocking activity and the potentiation of 5-HTP-induced behavioural syndrome is due to a metabolite's MAO-A inhibitory activity. As 2 h pretreatment with molindone induced catalepsy and antagonized apomorphine-induced climbing behaviour in mice and stereotypy in rats, while 24 h pretreatment failed to induce catalepsy and to antagonize apomorphine-induced behaviour, it appears that, at 24 h, the tissue levels of molindone are inadequate to block postsynaptic striatal and mesolimbic DA receptors and that, though a metabolite of molindone is biologically active so far as inhibition of MAO-A is concerned, the metabolites are devoid of neuroleptic activity. Further, since 2 h pretreatment with molindone failed to enhance the behavioural effects of L-dopa, it suggests that at 2 h the degree of MAO-A inhibition induced by molindone and/or the metabolite is not sufficient to counteract the neuroleptic activity of the parent compound.

Effects of long-term oral administration of levothyroxine sodium on glucose dynamics in healthy adult horses.

PubMed

Frank, Nicholas; Elliott, Sarah B; Boston, Raymond C

2008-01-01

To determine the effects of long-term oral administration of levothyroxine sodium (L-T(4)) on glucose dynamics in adult euthyroid horses. 6 healthy adult mares. Horses received L-T(4) (48 mg/d) orally for 48 weeks. Frequently sampled IV glucose tolerance test procedures were performed on 3 occasions (24-hour intervals) before and at 16, 32, and 48 weeks during the treatment period. Data were assessed via minimal model analysis. The repeatability of measurements was evaluated. During treatment, body weight decreased significantly from the pretreatment value; mean +/- SD weight was 49 +/- 14 kg, 43 +/- 7 kg, and 25 +/- 18 kg less than the pretreatment value at weeks 16, 32, and 48, respectively. Compared with pretreatment findings, 1.8-, 2.4-, and 1.9-fold increases in mean insulin sensitivity (SI) were detected at weeks 16, 32, and 48, respectively; SI was negatively correlated with body weight (r = -0.42; P < 0.001). During treatment, glucose effectiveness increased and the acute insulin response to glucose decreased. Overall mean within-horse coefficients of variation were 5% and 29% for plasma glucose and serum insulin concentrations, respectively, and 33%, 26%, and 23% for SI, glucose effectiveness, and the acute insulin response to glucose, respectively. Long-term administration of L-T(4) was associated with weight loss and increased SI in adult euthyroid horses, although other factors may have confounded results. Levothyroxine sodium may be useful for the treatment of obesity and insulin resistance in horses, but further studies are required.

Study on loading coefficient in steam explosion process of corn stalk.

PubMed

Sui, Wenjie; Chen, Hongzhang

2015-03-01

The object of this work was to evaluate the effect of loading coefficient on steam explosion process and efficacy of corn stalk. Loading coefficient's relation with loading pattern and material property was first revealed, then its effect on transfer process and pretreatment efficacy of steam explosion was assessed by established models and enzymatic hydrolysis tests, respectively, in order to propose its optimization strategy for improving the process economy. Results showed that loading coefficient was mainly determined by loading pattern, moisture content and chip size. Both compact loading pattern and low moisture content improved the energy efficiency of steam explosion pretreatment and overall sugar yield of pretreated materials, indicating that they are desirable to improve the process economy. Pretreatment of small chip size showed opposite effects in pretreatment energy efficiency and enzymatic hydrolysis performance, thus its optimization should be balanced in investigated aspects according to further techno-economical evaluation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Systematic evaluation of matrix effects in hydrophilic interaction chromatography versus reversed phase liquid chromatography coupled to mass spectrometry.

PubMed

Periat, Aurélie; Kohler, Isabelle; Thomas, Aurélien; Nicoli, Raul; Boccard, Julien; Veuthey, Jean-Luc; Schappler, Julie; Guillarme, Davy

2016-03-25

Reversed phase liquid chromatography (RPLC) coupled to mass spectrometry (MS) is the gold standard technique in bioanalysis. However, hydrophilic interaction chromatography (HILIC) could represent a viable alternative to RPLC for the analysis of polar and/or ionizable compounds, as it often provides higher MS sensitivity and alternative selectivity. Nevertheless, this technique can be also prone to matrix effects (ME). ME are one of the major issues in quantitative LC-MS bioanalysis. To ensure acceptable method performance (i.e., trueness and precision), a careful evaluation and minimization of ME is required. In the present study, the incidence of ME in HILIC-MS/MS and RPLC-MS/MS was compared for plasma and urine samples using two representative sets of 38 pharmaceutical compounds and 40 doping agents, respectively. The optimal generic chromatographic conditions in terms of selectivity with respect to interfering compounds were established in both chromatographic modes by testing three different stationary phases in each mode with different mobile phase pH. A second step involved the assessment of ME in RPLC and HILIC under the best generic conditions, using the post-extraction addition method. Biological samples were prepared using two different sample pre-treatments, i.e., a non-selective sample clean-up procedure (protein precipitation and simple dilution for plasma and urine samples, respectively) and a selective sample preparation, i.e., solid phase extraction for both matrices. The non-selective pretreatments led to significantly less ME in RPLC vs. HILIC conditions regardless of the matrix. On the contrary, HILIC appeared as a valuable alternative to RPLC for plasma and urine samples treated by a selective sample preparation. Indeed, in the case of selective sample preparation, the compounds influenced by ME were different in HILIC and RPLC, and lower and similar ME occurrence was generally observed in RPLC vs. HILIC for urine and plasma samples, respectively. The complementary of both chromatographic modes was also demonstrated, as ME was observed only scarcely for urine and plasma samples when selecting the most appropriate chromatographic mode. Copyright © 2015 Elsevier B.V. All rights reserved.

Pretreatment methods to improve nerve immunostaining in corneas from long-term fixed embryonic quail eyes

NASA Technical Reports Server (NTRS)

Barrett, J. E.; Wells, D. C.; Conrad, G. W.

1999-01-01

Pretreatment methods were used to improve neurofilament immunostaining in corneas from embryonic day 16 Japanese quail corneas that had been stored in fixative solution for several months. A sequential combination of the following three pretreatments: brief microwave heating in saline, followed by extraction with sodium dodecyl sulfate (SDS) at 37 degrees C, followed by digestion with hyaluronidase at 37 degrees C, produced significantly increased antibody staining of corneal neurofilament proteins, compared with embryonic corneas subjected to no prior pretreatments or to single or two-step protocols. After applying the sequence of all three pretreatments, darkest nerve staining and increased numbers of fine branches were observed, together with lower background staining. Thus, the result of applying the three-step pretreatment sequence is better than that of applying any of its component single pretreatments or even combinations of any two of them. These findings therefore suggest that each of these three pretreatments causes a unique effect, beneficial to immunostaining of neurofilament proteins, and that their individual effects are independent and additive. In addition to embryonic corneas, the three-step procedure also may be useful for immunostaining of nerves in other very delicate, highly-hydrated tissues containing an abundance of extracellular matrix.

Cell-wall structural changes in wheat straw pretreated for bioethanol production

PubMed Central

Kristensen, Jan B; Thygesen, Lisbeth G; Felby, Claus; Jørgensen, Henning; Elder, Thomas

2008-01-01

Background Pretreatment is an essential step in the enzymatic hydrolysis of biomass and subsequent production of bioethanol. Recent results indicate that only a mild pretreatment is necessary in an industrial, economically feasible system. The Integrated Biomass Utilisation System hydrothermal pretreatment process has previously been shown to be effective in preparing wheat straw for these processes without the application of additional chemicals. In the current work, the effect of the pretreatment on the straw cell-wall matrix and its components are characterised microscopically (atomic force microscopy and scanning electron microscopy) and spectroscopically (attenuated total reflectance Fourier transform infrared spectroscopy) in order to understand this increase in digestibility. Results The hydrothermal pretreatment does not degrade the fibrillar structure of cellulose but causes profound lignin re-localisation. Results from the current work indicate that wax has been removed and hemicellulose has been partially removed. Similar changes were found in wheat straw pretreated by steam explosion. Conclusion Results indicate that hydrothermal pretreatment increases the digestibility by increasing the accessibility of the cellulose through a re-localisation of lignin and a partial removal of hemicellulose, rather than by disruption of the cell wall. PMID:18471316

Impact of Thermal Pretreatment Temperatures on Woody Biomass Chemical Composition, Physical Properties and Microstructure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Ping; Howard, Bret H.

Thermal pretreatment of biomass by torrefaction and low temperature pyrolysis has the potential for generating high quality and more suitable fuels. To utilize a model to describe the complex and dynamic changes taking place during these two treatments for process design, optimization and scale-up, detailed data is needed on the property evolution during treatment of well-defined individual biomass particles. The objectives of this study are to investigate the influence of thermal pretreatment temperatures on wood biomass biochemical compositions, physical properties and microstructure. Wild cherry wood was selected as a model biomass and prepared for this study. The well-defined wood particlemore » samples were consecutively heated at 220, 260, 300, 350, 450 and 550 °C for 0.5 h under nitrogen. Untreated and treated samples were characterized for biochemical composition changes (cellulose, hemicellulose, and lignin) by thermogravimetric analyzer (TGA), physical properties (color, dimensions, weight, density and grindablity), chemical property (proximate analysis and heating value) and microstructural changes by scanning electron microscopy (SEM). Hemicellulose was mostly decomposed in the samples treated at 260 and 300 °C and resulted in the cell walls weakening resulting in improved grindability. The dimensions of the wood were reduced in all directions and shrinkage increased with increased treatment temperature and weight loss. With increased treatment temperature, losses of weight and volume increased and bulk density decreased. The low temperature pyrolyzed wood samples improved solid fuel property with high fuel ratio, which are close to lignite/bituminous coal. Morphology of the wood remained intact through the treatment range but the cell walls were thinner. Lastly, these results will improve the understanding of the property changes of the biomass during pretreatment and will help to develop models for process simulation and potential application of the treated biomass.« less

Impact of Thermal Pretreatment Temperatures on Woody Biomass Chemical Composition, Physical Properties and Microstructure

DOE PAGES

Wang, Ping; Howard, Bret H.

2017-12-23

Thermal pretreatment of biomass by torrefaction and low temperature pyrolysis has the potential for generating high quality and more suitable fuels. To utilize a model to describe the complex and dynamic changes taking place during these two treatments for process design, optimization and scale-up, detailed data is needed on the property evolution during treatment of well-defined individual biomass particles. The objectives of this study are to investigate the influence of thermal pretreatment temperatures on wood biomass biochemical compositions, physical properties and microstructure. Wild cherry wood was selected as a model biomass and prepared for this study. The well-defined wood particlemore » samples were consecutively heated at 220, 260, 300, 350, 450 and 550 °C for 0.5 h under nitrogen. Untreated and treated samples were characterized for biochemical composition changes (cellulose, hemicellulose, and lignin) by thermogravimetric analyzer (TGA), physical properties (color, dimensions, weight, density and grindablity), chemical property (proximate analysis and heating value) and microstructural changes by scanning electron microscopy (SEM). Hemicellulose was mostly decomposed in the samples treated at 260 and 300 °C and resulted in the cell walls weakening resulting in improved grindability. The dimensions of the wood were reduced in all directions and shrinkage increased with increased treatment temperature and weight loss. With increased treatment temperature, losses of weight and volume increased and bulk density decreased. The low temperature pyrolyzed wood samples improved solid fuel property with high fuel ratio, which are close to lignite/bituminous coal. Morphology of the wood remained intact through the treatment range but the cell walls were thinner. Lastly, these results will improve the understanding of the property changes of the biomass during pretreatment and will help to develop models for process simulation and potential application of the treated biomass.« less

The antiepileptic effect of Centella asiatica on the activities of Na+/K+, Mg2+ and Ca2+-ATPases in rat brain during pentylenetetrazol–induced epilepsy

PubMed Central

G., Visweswari; K., Siva Prasad; V., Lokanatha; Rajendra, W.

2010-01-01

Background: To study the anticonvulsant effect of different extracts of Centella asiatica (CA) in male albino rats with reference to Na+/K+, Mg2+ and Ca2+-ATPase activities. Materials and Methods: Male Wistar rats (150±25 g b.w.) were divided into seven groups of six each i.e. (a) control rats treated with saline, (b) pentylenetetrazol (PTZ)-induced epileptic group (60 mg/kg, i.p.), (c) epileptic group pretreated with n-hexane extract (n-HE), (d) epileptic group pretreated with chloroform extract (CE), (e) epileptic group pretreated with ethyl acetate extract (EAE), (f) epileptic group pretreated with n-butanol extract (n-BE), and (g) epileptic group pretreated with aqueous extract (AE). Results: The activities of three ATPases were decreased in different regions of brain during PTZ-induced epilepsy and were increased in epileptic rats pretreated with different extracts of CA except AE. Conclusion: The extracts of C. asiatica, except AE, possess anticonvulsant and neuroprotective activity and thus can be used for effective management in treatment of epileptic seizures. PMID:20711371

Microwave-assisted inorganic salt pretreatment of sugarcane leaf waste: Effect on physiochemical structure and enzymatic saccharification.

PubMed

Moodley, Preshanthan; Kana, E B Gueguim

2017-07-01

This paper presents a method to pretreat sugarcane leaf waste using microwave-assisted (MA) inorganic salt to enhance enzymatic saccharification. The effects of process parameters of salt concentration, microwave power intensity and pretreatment time on reducing sugar yield from sugarcane leaf waste were investigated. Pretreatment models based on MA-NaCl, MA-ZnCl 2 and MA-FeCl 3 were developed with high coefficients of determination (R 2 >0.8) and optimized. Maximum reducing sugar yield of 0.406g/g was obtained with 2M FeCl 3 at 700W for 3.5min. Scanning electron microscopy (SEM), Fourier Transform Infrared analysis (FTIR) and X-ray diffraction (XRD) showed major changes in lignocellulosic structure after MA-FeCl 3 pretreatment with 71.5% hemicellulose solubilization. This regime was further assessed on sorghum leaves and Napier grass under optimal MA-FeCl 3 conditions. A 2-fold and 3.1-fold increase in sugar yield respectively were observed compared to previous reports. This pretreatment was highly effective for enhancing enzymatic saccharification of lignocellulosic biomass. Copyright © 2017. Published by Elsevier Ltd.

Effect of Panpal pretreatment and antidotal treatment (HI-6 plus benactyzine) on respiratory and circulatory function in soman-poisoned rats.

PubMed

Kassa, J; Fusek, J

1997-10-01

1 The effect of pharmacological pretreatment (pyridostigmine, benactyzine and trihexyphenidyle), designated Panpal, and antidotal treatment (the oxime HI-6 plus benactyzine) in soman poisoning was investigated in a rat model with on-line monitoring of respiratory and circulatory parameters. 2 Soman poisoning caused a high decrease in respiratory rate as well as minute respiratory volume and an increase in mean arterial pressure from 30-120 min following soman challenge. Soman at sublethal dose also significantly inhibited acetylcholinesterase activity in diaphragm and various brain parts. 3 Panpal pretreatment as well as antidotal treatment were effective in improving the respiratory and circulatory function disturbed by soman without the ability to increase significantly soman-inhibited acetylcholinesterase activity in all brain parts studied. 4 The efficacy of combined Panpal pretreatment and antidotal treatment against sublethal soman poisoning was not different from the efficacy of Panpal pretreatment or antidotal treatment alone. 5 The results of this investigation suggest that Panpal pretreatment as well as antidotal treatment are able to restore respiratory and circulatory function in soman-poisoned rats without significant reactivation of brain acetylcholinesterase.

The effect of carbon monoxide pretreatment exposure time on the colour stability and quality attributes of vacuum packaged beef steaks.

PubMed

Van Rooyen, Lauren Anne; Allen, Paul; Crawley, Sarah M; O'Connor, David I

2017-07-01

The effect of 5% CO pretreatments prior to vacuum packaging of beef striploin steaks (Longissimus thoracis et lumborum, LTL) on quality attributes, primarily colour stability was investigated. The aim was to determine the optimum pretreatment that would induce the desirable red colour, while allowing discoloration to occur by the end of a 28-day display period (2°C), so as to not mask spoilage. A range of pretreatment exposure times (1, 3, 5, 7, 9, 15 and 24h) were applied to steaks using a gas mixture of 5% CO, 60% CO 2 and 35% N 2 . The 5h CO pretreatment exposure time achieved the desirable colour and discoloration reached unacceptable levels (a*=12, C*=16) by the use-by date (28days), thus ensuring consumers' of a reliable visual indication of freshness and addressing concerns about safety. The 5% CO pretreatment had no negative effect on microbiological safety, lipid oxidation, cooking loss and WBSF measurements at the end of storage (P>0.05). Copyright © 2017 Elsevier Ltd. All rights reserved.

Simultaneous saccharification and fermentation (SSF) of Jatropha curcas shells: utilization of co-products from the biodiesel production process.

PubMed

Visser, Evan Michael; Oliveira Filho, Delly; Tótola, Marcos Rogério; Martins, Marcio Arêdes; Guimarães, Valéria Monteze

2012-06-01

Jatropha curcas has great potential as an oil crop for use in biodiesel applications, and the outer shell is rich in lignocellulose that may be converted to ethanol, giving rise to the concept of a biorefinery. In this study, two dilute pretreatments of 0.5% H(2)SO(4) and 1.0% NaOH were performed on Jatropha shells with subsequent simultaneous saccharification and fermentation (SSF) of the pretreated water-insoluble solids (WIS) to evaluate the effect of inhibitors in the pretreatment slurry. A cellulase loading of 15 FPU/g WIS, complimented with an excess of cellobiase (19.25 U/g), was used for SSF of either the washed WIS or the original slurry to determine the effect of inhibitors. Ethanol and glucose were monitored during SSF of 20 g of pretreated biomass. The unwashed slurry showed to have a positive effect on SSF efficiency for the NaOH-pretreated biomass. Maximum efficiencies of glucan conversion to ethanol in the WIS were 40.43% and 41.03% for the H(2)SO(4)- and NaOH-pretreated biomasses, respectively.

Combinatorial pretreatment and fermentation optimization enabled a record yield on lignin bioconversion.

PubMed

Liu, Zhi-Hua; Xie, Shangxian; Lin, Furong; Jin, Mingjie; Yuan, Joshua S

2018-01-01

Lignin valorization has recently been considered to be an essential process for sustainable and cost-effective biorefineries. Lignin represents a potential new feedstock for value-added products. Oleaginous bacteria such as Rhodococcus opacus can produce intracellular lipids from biodegradation of aromatic substrates. These lipids can be used for biofuel production, which can potentially replace petroleum-derived chemicals. However, the low reactivity of lignin produced from pretreatment and the underdeveloped fermentation technology hindered lignin bioconversion to lipids. In this study, combinatorial pretreatment with an optimized fermentation strategy was evaluated to improve lignin valorization into lipids using R. opacus PD630. As opposed to single pretreatment, combinatorial pretreatment produced a 12.8-75.6% higher lipid concentration in fermentation using lignin as the carbon source. Gas chromatography-mass spectrometry analysis showed that combinatorial pretreatment released more aromatic monomers, which could be more readily utilized by lignin-degrading strains. Three detoxification strategies were used to remove potential inhibitors produced from pretreatment. After heating detoxification of the lignin stream, the lipid concentration further increased by 2.9-9.7%. Different fermentation strategies were evaluated in scale-up lipid fermentation using a 2.0-l fermenter. With laccase treatment of the lignin stream produced from combinatorial pretreatment, the highest cell dry weight and lipid concentration were 10.1 and 1.83 g/l, respectively, in fed-batch fermentation, with a total soluble substrate concentration of 40 g/l. The improvement of the lipid fermentation performance may have resulted from lignin depolymerization by the combinatorial pretreatment and laccase treatment, reduced inhibition effects by fed-batch fermentation, adequate oxygen supply, and an accurate pH control in the fermenter. Overall, these results demonstrate that combinatorial pretreatment, together with fermentation optimization, favorably improves lipid production using lignin as the carbon source. Combinatorial pretreatment integrated with fed-batch fermentation was an effective strategy to improve the bioconversion of lignin into lipids, thus facilitating lignin valorization in biorefineries.

Application of chemometrics to assess the influence of ultrasound frequency, Lactobacillus sakei culture and drying on beef jerky manufacture: Impact on amino acid profile, organic acids, texture and colour.

PubMed

Shikha Ojha, K; Granato, Daniel; Rajuria, Gaurav; Barba, Francisco J; Kerry, Joseph P; Tiwari, Brijesh K

2018-01-15

The effects of ultrasound (US) frequency, addition of Lactobacillus sakei culture and drying time on key nutritional (protein, amino acids, and organic acids) and physicochemical properties (texture and colour) of cultured and uncultured beef jerky were evaluated. Cultured and uncultured jerky samples were subjected to US frequencies of 25kHz, 33kHz and 45kHz for 30min prior to marination and drying. Principal component analysis demonstrated a significant effect of beef jerky processing conditions on physicochemical properties. Taurine content of jerky samples was found to increase with an increase in ultrasonic frequencies for cultured samples. No significant changes in colour values were observed for ultrasound pre-treated and control samples. Interactive effects of culture treatment, drying and ultrasonic frequency were observed. This study demonstrates that the nutritional profile of beef jerky can be improved through the incorporation of L. sakei. Copyright © 2017 Elsevier Ltd. All rights reserved.

An in vitro investigation of pre-treatment effects before fissure sealing.

PubMed

Bagheri, Mahshid; Pilecki, Peter; Sauro, Salvatore; Sherriff, Martyn; Watson, Timothy F; Hosey, Marie Therese

2017-11-01

Fissure sealants prevent occlusal caries in permanent molars. Enamel preparation methods are used before fissure sealing. To investigate effects of bioglass air-abrasion pre-treatment with and without an adhesive, on fissure enamel of permanent teeth, with respect to etchability, microleakage and microtensile bond strength. Half of the occlusal surfaces of 50 extracted premolars underwent bioglass air-abrasion. Dye was applied to the entire occlusal surface. Photographs were taken to score etched surface by dye uptake. Adhesive was applied to 25 of the bioglass-treated areas and all teeth were fissure sealed, sectioned, and evaluated using confocal microscopy. Buccal and lingual surfaces of a further eight premolars were acid-etched and randomly received: air-abrasion, adhesive, both, or none before sealant application for microtensile bond strength measurement in half of the samples immediately and half following 6 months of water immersion. Linear mixed models and multinomial logistic regression were used (P = 0.05). Bioglass air-abrasion significantly improved enamel etchability and reduced microleakage. The addition of an adhesive made no difference to either microleakage or microtensile bond strength. The combination of bioglass abrasion and adhesive led to more cohesive, rather than adhesive, failure. Bioglass air-abrasion improved enamel etchability and reduced microleakage irrespective of the adhesive use but neither pre-treatment affected the microtensile bond strength. © 2017 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparing the effects of three pre-treatment disintegration techniques on aerobic sludge digestion: biodegradability enhancement and microbial community monitoring by PCR-DGGE.

PubMed

Jaziri, Kais; Casellas, Magali; Dagot, Christophe

2012-06-01

The objectives of this work were to compare and investigate the effect of three activated sludge disintegration processes before aerobic sludge digestion on 1) aerobic biodegradability enhancement and 2) microbial community evolution using the polymerase chain reaction-denaturant gel gradient electrophoresis (PCR-DGGE) technique. The comparison of three disintegration processes: thermal treatment (95 degrees C, 2h), sonication (100,000 kJ/kgTS) and ozonation (0.108 g O3/gTS) showed that the disintegration processes acted differently according to the composition of the soluble phase and to the DNA damage. Thermal treatment led to significant protein solubilization and to DNA modification. Sonication and ozonation resulted in similar soluble phase compositions and did not lead to any DNA modifications. During activated sludge aerobic digestion, intrinsic biodegradability enhancement was observed for thermal and ozone activated sludge pre-treatments. The analysis of the DGGE patterns at the end of aerobic digestion showed that population diversity was affected by both the aerobic digestion and the pre-treatment. The dissimilarity percentages measured at the end of aerobic digestion in the control sample and in the treated sludge were equal to 22, 25 and 20% for thermal treatment, sonication and ozonation respectively. This study indicated that PCR-DGGE could be a useful tool for the comparison of disintegration processes before and after aerobic digestion.

Heparin removal by ecteola-cellulose pre-treatment enables the use of plasma samples for accurate measurement of anti-Yellow fever virus neutralizing antibodies.

PubMed

Campi-Azevedo, Ana Carolina; Peruhype-Magalhães, Vanessa; Coelho-Dos-Reis, Jordana Grazziela; Costa-Pereira, Christiane; Yamamura, Anna Yoshida; Lima, Sheila Maria Barbosa de; Simões, Marisol; Campos, Fernanda Magalhães Freire; de Castro Zacche Tonini, Aline; Lemos, Elenice Moreira; Brum, Ricardo Cristiano; de Noronha, Tatiana Guimarães; Freire, Marcos Silva; Maia, Maria de Lourdes Sousa; Camacho, Luiz Antônio Bastos; Rios, Maria; Chancey, Caren; Romano, Alessandro; Domingues, Carla Magda; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis

2017-09-01

Technological innovations in vaccinology have recently contributed to bring about novel insights for the vaccine-induced immune response. While the current protocols that use peripheral blood samples may provide abundant data, a range of distinct components of whole blood samples are required and the different anticoagulant systems employed may impair some properties of the biological sample and interfere with functional assays. Although the interference of heparin in functional assays for viral neutralizing antibodies such as the functional plaque-reduction neutralization test (PRNT), considered the gold-standard method to assess and monitor the protective immunity induced by the Yellow fever virus (YFV) vaccine, has been well characterized, the development of pre-analytical treatments is still required for the establishment of optimized protocols. The present study intended to optimize and evaluate the performance of pre-analytical treatment of heparin-collected blood samples with ecteola-cellulose (ECT) to provide accurate measurement of anti-YFV neutralizing antibodies, by PRNT. The study was designed in three steps, including: I. Problem statement; II. Pre-analytical steps; III. Analytical steps. Data confirmed the interference of heparin on PRNT reactivity in a dose-responsive fashion. Distinct sets of conditions for ECT pre-treatment were tested to optimize the heparin removal. The optimized protocol was pre-validated to determine the effectiveness of heparin plasma:ECT treatment to restore the PRNT titers as compared to serum samples. The validation and comparative performance was carried out by using a large range of serum vs heparin plasma:ECT 1:2 paired samples obtained from unvaccinated and 17DD-YFV primary vaccinated subjects. Altogether, the findings support the use of heparin plasma:ECT samples for accurate measurement of anti-YFV neutralizing antibodies. Copyright © 2017 Elsevier B.V. All rights reserved.

Pretreatment tables predicting pathologic stage of locally advanced prostate cancer.

PubMed

Joniau, Steven; Spahn, Martin; Briganti, Alberto; Gandaglia, Giorgio; Tombal, Bertrand; Tosco, Lorenzo; Marchioro, Giansilvio; Hsu, Chao-Yu; Walz, Jochen; Kneitz, Burkhard; Bader, Pia; Frohneberg, Detlef; Tizzani, Alessandro; Graefen, Markus; van Cangh, Paul; Karnes, R Jeffrey; Montorsi, Francesco; van Poppel, Hein; Gontero, Paolo

2015-02-01

Pretreatment tables for the prediction of pathologic stage have been published and validated for localized prostate cancer (PCa). No such tables are available for locally advanced (cT3a) PCa. To construct tables predicting pathologic outcome after radical prostatectomy (RP) for patients with cT3a PCa with the aim to help guide treatment decisions in clinical practice. This was a multicenter retrospective cohort study including 759 consecutive patients with cT3a PCa treated with RP between 1987 and 2010. Retropubic RP and pelvic lymphadenectomy. Patients were divided into pretreatment prostate-specific antigen (PSA) and biopsy Gleason score (GS) subgroups. These parameters were used to construct tables predicting pathologic outcome and the presence of positive lymph nodes (LNs) after RP for cT3a PCa using ordinal logistic regression. In the model predicting pathologic outcome, the main effects of biopsy GS and pretreatment PSA were significant. A higher GS and/or higher PSA level was associated with a more unfavorable pathologic outcome. The validation procedure, using a repeated split-sample method, showed good predictive ability. Regression analysis also showed an increasing probability of positive LNs with increasing PSA levels and/or higher GS. Limitations of the study are the retrospective design and the long study period. These novel tables predict pathologic stage after RP for patients with cT3a PCa based on pretreatment PSA level and biopsy GS. They can be used to guide decision making in men with locally advanced PCa. Our study might provide physicians with a useful tool to predict pathologic stage in locally advanced prostate cancer that might help select patients who may need multimodal treatment. Copyright © 2014 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Effects of haloperidol on the behavioral, subjective, cognitive, motor, and neuroendocrine effects of Δ-9-tetrahydrocannabinol in humans

PubMed Central

Braley, Gabriel; Blaise, Rebecca; Vendetti, Michael; Oliver, Stephen; Pittman, Brian; Ranganathan, Mohini; Bhakta, Savita; Zimolo, Zoran; Cooper, Thomas; Perry, Edward

2010-01-01

Introduction Cannabinoids produce a spectrum of effects in humans including euphoria, cognitive impairments, psychotomimetic effects, and perceptual alterations. The extent to which dopaminergic systems contribute to the effects of Δ-9-tetrahydrocannabinol (Δ-9-THC) remains unclear. This study evaluated whether pretreatment with a dopamine receptor antagonist altered the effects of Δ-9-THC in humans. Materials and methods In a 2-test-day double-blind study, 28 subjects including healthy subjects (n=17) and frequent users of cannabis (n=11) were administered active (0.057 mg/kg) or placebo oral haloperidol in random order followed 90 and 215 min later by fixed order intravenous administration of placebo (vehicle) and active (0.0286 mg/kg) Δ-9-THC, respectively. Results Consistent with previous reports, intravenous Δ-9-THC produced psychotomimetic effects, perceptual alterations, and subjective effects including “high.” Δ-9-THC also impaired verbal recall and attention. Haloperidol pretreatment did not reduce any of the behavioral effects of Δ-9-THC. Haloperidol worsened the immediate free and delayed free and cued recall deficits produced by Δ-9-THC. Haloperidol and Δ-9-THC worsened distractibility and vigilance. Neither drug impaired performance on a motor screening task, the Stockings of Cambridge task, or the delayed match to sample task. Frequent users had lower baseline plasma prolactin levels and blunted Δ-9-THC induced memory impairments. Conclusions The deleterious effects of haloperidol pretreatment on the cognitive effects of Δ-9-THC are consistent with the preclinical literature in suggesting crosstalk between DAergic and CBergic systems. However, it is unlikely that DA D2 receptor mechanisms play a major role in mediating the psychotomimetic and perceptual altering effects of Δ-9-THC. Further investigation is warranted to understand the basis of the psychotomimetic effects of Δ-9-THC and to better understand the crosstalk between DAergic and CBergic systems. PMID:18228005

Hydrothermal pre-treatment of rapeseed straw.

PubMed

Díaz, Manuel J; Cara, Cristóbal; Ruiz, Encarnación; Romero, Inmaculada; Moya, Manuel; Castro, Eulogio

2010-04-01

As a first step for ethanol production from alternative raw materials, rapeseed straw was studied for fermentable sugar production. Liquid hot water was used as a pre-treatment method and the influence of the main pre-treatment variables was assessed. Experimental design and response surface methodology were applied using pre-treatment temperature and process time as factors. The pretreated solids were further submitted to enzymatic hydrolysis and the corresponding yields were used as pre-treatment performance evaluation. Liquid fractions obtained from pre-treatment were also characterized in terms of sugars and no-sugar composition. A mathematical model describing pre-treatment effects is proposed. Results show that enzymatic hydrolysis yields near to 100% based on pretreated materials can be achieved at 210-220 degrees C for 30-50 min, equivalent to near 70% of glucose present in the raw material. According to the mathematical model, a softer pre-treatment at 193 degrees C for 27 min results in 65% of glucose and 39% of xylose available for fermentation. Copyright 2009 Elsevier Ltd. All rights reserved.

Peracetic acid-ionic liquid pretreatment to enhance enzymatic saccharification of lignocellulosic biomass.

PubMed

Uju; Abe, Kojiro; Uemura, Nobuyuki; Oshima, Toyoji; Goto, Masahiro; Kamiya, Noriho

2013-06-01

To enhance enzymatic saccharification of pine biomass, the pretreatment reagents peracetic acid (PAA) and ionic liquid (IL) were validated in single reagent pretreatments or combination pretreatments with different sequences. In a 1h saccharification, 5-25% cellulose conversion was obtained from the single pretreatment of PAA or IL. In contrast, a marked enhancement in conversion rates was achieved by PAA-IL combination pretreatments (45-70%). The PAA followed by IL (PAA+IL) pretreatment sequence was the most effective for preparing an enzymatic digestible regenerated biomass with 250-fold higher glucose formation rates than untreated biomass and 2- to 12-fold higher than single pretreatments with PAA or IL alone. Structural analysis confirmed that this pretreatment resulted in biomass with highly porous structural fibers associated with the reduction of lignin content and acetyl groups. Using the PAA+IL sequence, biomass loading in the pretreatment step can be increased from 5% to 15% without significant decrease in cellulose conversion. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of pre-treatment technologies on dark fermentative biohydrogen production: A review.

PubMed

Bundhoo, M A Zumar; Mohee, Romeela; Hassan, M Ali

2015-07-01

Biohydrogen production from dark fermentation of lignocellulosic materials represents a huge potential in terms of renewable energy exploitation. However, the low hydrogen yield is currently hindering its development on industrial scale. This study reviewed various technologies that have been investigated for enhancing dark fermentative biohydrogen production. The pre-treatment technologies can be classified based on their applications as inoculum or substrates pre-treatment or they can be categorised into physical, chemical, physicochemical and biological based on the techniques used. From the different technologies reviewed, heat and acid pre-treatments are the most commonly studied technologies for both substrates and inoculum pre-treatment. Nevertheless, these two technologies need not necessarily be the most suitable since across different studies, a wide array of other emerging techniques as well as combined technologies have yielded positive findings. To date, there exists no perfect technology for either inoculum or substrate pre-treatment. Although the aim of inoculum pre-treatment is to suppress H2-consumers and enrich H2-producers, many sporulating H2-consumers survive the pre-treatment while some non-spore H2-producers are inhibited. Besides, several inoculum pre-treatment techniques are not effective in the long run and repeated pre-treatment may be required for continuous suppression of H2-consumers and sustained biohydrogen production. Furthermore, many technologies employed for substrates pre-treatment may yield inhibitory compounds that can eventually decrease biohydrogen production. Consequently, much research needs to be done to find out the best technology for both substrates and inoculum pre-treatment while also taking into consideration the energetic, economic and technical feasibility of implementing such a process on an industrial scale. Copyright © 2015 Elsevier Ltd. All rights reserved.

Transdermal testosterone pretreatment in poor responders undergoing ICSI: a randomized clinical trial.

PubMed

Bosdou, J K; Venetis, C A; Dafopoulos, K; Zepiridis, L; Chatzimeletiou, K; Anifandis, G; Mitsoli, A; Makedos, A; Messinis, I E; Tarlatzis, B C; Kolibianakis, E M

2016-05-01

Does pretreatment with transdermal testosterone increase the number of cumulus-oocyte complexes (COCs) retrieved by more than 1.5 in poor responders undergoing intracytoplasmic sperm injection (ICSI), using recombinant follicle stimulating hormone (FSH) and gonadotrophin releasing hormone agonists (GnRHa)? Testosterone pretreatment failed to increase the number of COCs by more than 1.5 as compared with no pretreatment in poor responders undergoing ICSI (difference between medians: 0.0, 95% CI: -1.0 to +1.0). Androgens are thought to play an important role in early follicular development by enhancing ovarian sensitivity to FSH. In a recent meta-analysis, testosterone pretreatment resulted in an increase of 1.5 COCs as compared with no pretreatment. However, this effect was based on the analysis of only two randomized controlled trials (RCTs) including 163 patients. Evidently, there is a need for additional RCTs that will allow firmer conclusions to be drawn. The present RCT was designed to detect a difference of 1.5 COCs (sample size required = 48 patients). From 02/2014 until 04/2015, 50 poor responders fulfilling the Bologna criteria have been randomized (using a randomization list) to either testosterone pretreatment for 21 days ( ITALIC! n = 26) or no pretreatment ( ITALIC! n = 24). All patients underwent a long follicular GnRHa protocol. Recombinant FSH stimulation was started on Day 22 following GnRHa initiation. In the testosterone pretreatment group, a daily dose of 10 mg of testosterone gel was applied transdermally for 21 days starting from GnRHa initiation. Results are expressed as median (interquartile range). No differences in baseline characteristics were observed between the two groups compared. Testosterone levels [median (interquartile range)] were significantly higher in the testosterone pretreatment on the day of initiation of FSH stimulation [114 (99.5) ng/dl versus 20 (20) ng/dl, respectively, ITALIC! P < 0.001]. Duration of FSH stimulation [median (interquartile range)] was similar between the groups compared [12.5 (3.0) days versus 12 (3.0) days, respectively, ITALIC! P = 0.52]. The number of COCs retrieved [median (interquartile range)] was not different between the testosterone pretreatment and the no pretreatment groups [3.5 (4.0) versus 3.0 (3.0), 95% CI for the median: 2.0-5.0 versus 2.7-4.3, respectively; difference between medians: 0.0, 95% CI: +1.0 to -1.0). Similarly no differences were observed regarding fertilization rates [median (interquartile range)] [66.7% (32.5) versus 66.7% (42.9), respectively, ITALIC! P = 0.97] and live birth rates per randomized patient (7.7% versus 8.3%, respectively, rate difference: -0.6%, 95% CI: -19.0 to +16.9). The study was not powered to detect differences less than 1.5 COCs, although it is doubtful whether these differences would be clinically relevant. Moreover, due to sample size restrictions, no conclusions can be drawn regarding the probability of live birth. The results of this randomized clinical trial, suggesting that pretreatment with 10 mg of transdermal testosterone for 21 days does not improve ovarian response by more than 1.5 oocytes, could be used to more accurately consult patients with poor ovarian response. However, an improvement in IVF outcome using a higher dose of testosterone or a longer pretreatment period cannot be excluded. The study was partially funded by a Scholarship from the Academy of Athens. C.A.V. reports personal fees and non-financial support from Merck, Sharp and Dome, personal fees and non-financial support from Merck Serono, personal fees and non-financial support from IPSEN Hellas S.A., outside the submitted work. B.C.T. reports grants from Merck Serono, grants from Merck Sharp & Dohme, personal fees from Merck Serono, personal fees from Merck Sharp & Dohme, personal fees from IBSA & Ferring, outside the submitted work. NCT01961336. 10 October 2013. 02/2014. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Efficacy of continuous positive airway pressure for treatment of hypernasality.

PubMed

Kuehn, David P; Imrey, Peter B; Tomes, Lucrezia; Jones, David L; O'Gara, Mary M; Seaver, Earl J; Smith, Bonnie E; Van Demark, D R; Wachtel, Jayne M

2002-05-01

To determine whether speech hypernasality in subjects born with cleft palate can be reduced by graded velopharyngeal resistance training against continuous positive airway pressure (CPAP). Pretreatment versus immediate posttreatment comparison study. Eight university and hospital speech clinics. Forty-three subjects born with cleft palate, aged 3 years 10 months to 23 years 8 months, diagnosed with speech hypernasality. Eight weeks of 6 days per week in-home speech exercise sessions, increasing from 10 to 24 minutes, speaking against transnasal CPAP increasing from 4 to 8.5 cm H(2)0. MAIN OUTCOME MEASURES Pretreatment to immediate posttherapy change in perceptual nasality score based on blinded comparisons of subjects' speech samples to standard reference samples by six expert clinician-investigators. Participating clinical centers treated from two to nine eligible subjects, and results differed significantly across centers (interaction p =.004). Overall, there was statistically significant reduction in mean nasality score after 8 weeks of CPAP therapy, whether weighted equally across patients (mean reduction = 0.20 units on a scale of 1.0 to 7.0, p =.016) or across clinical centers (mean = 0.19, p =.046). This change was about one-sixth the maximum possible reduction from pretreatment. Nine patients showed reductions of at least half the maximum possible, but hypernasality of eight patients increased at least 30% above pretreatment level. Most improvement was seen during the second month when therapy was more intense (p =.045 for nonlinearity). No interactions with age or sex were detected. Patients receiving 8 weeks of velopharyngeal CPAP resistance training showed a net overall reduction in speech hypernasality, although response was quite variable across patients and clinical centers. The net reduction in hypernasality is not readily explainable by random variability, subject maturation, placebo effect, or regression to the mean. CPAP appears capable of substantially reducing speech hypernasality for some subjects with cleft palate.

Micro-pulverized extraction pretreatment for highly sensitive analysis of 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol in hair by liquid chromatography/tandem mass spectrometry.

PubMed

Kuwayama, Kenji; Miyaguchi, Hajime; Yamamuro, Tadashi; Tsujikawa, Kenji; Kanamori, Tatsuyuki; Iwata, Yuko T; Inoue, Hiroyuki

2015-11-30

A primary metabolite of Δ(9) -tetrahydrocannabinol, 11-nor-9-carboxytetrahydrocannabinol (THC-COOH), serves as an effective indicator for cannabis intake. According to the recommendations of the Society of Hair Testing, at least 0.2 pg/mg of THC-COOH (cut-off level) must be present in a hair sample to constitute a positive result in a drug test. Typically, hair is digested with an alkaline solution and is subjected to gas chromatography/tandem mass spectrometry (GC/MS/MS) with negative ion chemical ionization (NICI). It is difficult to quantify THC-COOH at the cut-off level using liquid chromatography/tandem mass spectrometry (LC/MS/MS) without acquisition of second-generation product ions in triple quadrupole-ion trap mass spectrometers, because large amounts of matrix components in the low-mass range produced by digestion interfere with the THC-COOH peak. Using the typical pretreatment method (alkaline dissolution) and micro-pulverized extraction (MPE) with a stainless bullet, we compared the quantification of THC-COOH using GC/MS/MS and LC/MS/MS. MPE reduced the amount of matrix components in the low-mass range and enabled the quantification of THC-COOH at 0.2 pg/mg using a conventional triple quadrupole liquid chromatograph coupled to a mass spectrometer. On the other hand, the MPE pretreatment was unsuitable for GC/MS/MS, probably due to matrix components in the high-mass range. The proper combination of pretreatments and instrumental analyses was shown to be important for detecting trace amounts of THC-COOH in hair. In MPE, samples can be prepared rapidly, and LC/MS/MS is readily available, unlike GC/MS/MS with NICI. The combination of MPE and LC/MS/MS might therefore be used in the initial screening for THC-COOH in hair prior to confirmatory analysis using GC/MS/MS with NICI. Copyright © 2015 John Wiley & Sons, Ltd.

The importance of interleukin-8 as a neutrophil chemoattractant in the lungs of cattle with pneumonic pasteurellosis.

PubMed Central

Caswell, J L; Middleton, D M; Gordon, J R

2001-01-01

Interleukin-8 (IL-8), an in vitro and in vivo neutrophil chemoattractant, is expressed at high levels in the lesions observed in bovine pneumonic pasteurellosis. Because of the role of neutrophils in the pathogenesis of pneumonic pasteurellosis, we investigated the relative importance of IL-8 as a neutrophil chemoattractant in this disease. Bronchoalveolar lavage (BAL) fluid was harvested from calves experimentally infected with bovine herpesvirus-1 and challenged with Mannheimia haemolytica. Neutrophil chemotactic activity was measured in pneumonic BAL fluid samples treated with a neutralizing monoclonal antibody to ovine IL-8, and compared to the activity in samples treated with an isotype-matched control antibody. Bronchoalveolar lavage fluid was analyzed at a dilution which induced a half-maximal response, and the concentrations of antibody were optimized in a preliminary experiment. Following incubation of replicate samples of diluted pneumonic bovine BAL fluid with 70 microg/mL of IL-8-neutralizing antibody or control antibody, the neutrophil chemotactic activities of the samples were determined using an in vitro microchemotaxis assay. Overall, pretreatment of BAL fluid samples with neutralizing anti-IL-8 antibody reduced neutrophil chemotactic activity by 15% to 60%, compared to pretreatment with control antibody. This effect was highly significant (P < 0.001), and was present in 5 of 5 samples. These data indicate that IL-8 is an important neutrophil chemoattractant in calves with pneumonic pasteurellosis, but that mediators with actions redundant to those of IL-8 must also be present in the lesions. PMID:11768129

Impact of Pretreatment Change on Mechanism of Behavior Change Research: An Applied Example Using Alcohol Abstinence Self-Efficacy.

PubMed

Noyes, Emily T; Levine, Jacob A; Schlauch, Robert C; Crane, Cory A; Connors, Gerard J; Maisto, Stephen A; Dearing, Ronda L

2018-03-01

With the growing recognition that, for some, significant changes in drinking occur before the first treatment session (i.e., pretreatment change), researchers have called for the careful assessment of when change occurs and its potential impact on mechanism of behavior change (MOBC) research. Using a commonly hypothesized MOBC variable, alcohol abstinence self-efficacy, the primary aim of this study was to examine the effect of pretreatment change on the study of MOBCs. Sixty-three individuals diagnosed with alcohol dependence were recruited to participate in a 12-week cognitive-behavioral treatment. Participants completed weekly assessments of self-efficacy and drinking behaviors. Multilevel time-lagged regression models indicated that pretreatment change significantly moderated the effect of self-efficacy on the number of drinking days, such that among those higher on pretreatment change, higher self-efficacy ratings predicted lower rates of drinking days in the week until the next treatment session. In contrast, pretreatment change did not moderate the effect of self-efficacy on the rate of heavy drinking days. Results from the current study add to a small but growing body of research highlighting the importance of pretreatment change when studying MOBCs. Further, these results provide important insights into the conditions in which self-efficacy may play an important role in treatment outcomes.

Isolation and structural characterization of sugarcane bagasse lignin after dilute phosphoric acid plus steam explosion pretreatment and its effect on cellulose hydrolysis

Treesearch

Jijiao Zeng; Zhaohui Tong; Letian Wang; J.Y. Zhu; Lonnie Ingram

2014-01-01

The structure of lignin after dilute phosphoric acid plus steam explosion pretreatment process of sugarcane bagasse in a pilot scale and the effect of the lignin extracted by ethanol on subsequent cellulose hydrolysis were investigated. The lignin structural changes caused by pretreatment were identified using advanced nondestructive techniques such as gel permeation...

Effects of SPORL and dilute acid pretreatment on substrate morphology, cell physical and chemical wall structures, and subsequent enzymatic hydrolysis of lodgepole pine

Treesearch

Xinping Li; Xiaolin Luo; Kecheng Li; J.Y. Zhu; J. Dennis Fougere; Kimberley Clarke

2012-01-01

The effects of pretreatment by dilute acid and sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) on substrate morphology, cell wall physical and chemical structures, along with the subsequent enzymatic hydrolysis of lodgepole pine substrate were investigated. FE-SEM and TEM images of substrate structural morphological changes showed that SPORL...

Amelioration de l'adhesion de revetements organiques deposes par plasma froid sur polymeres pour applications biomedicales

NASA Astrophysics Data System (ADS)

Sbai, Marouan

Plasma surface modification is commonly used in biomedical field, for example to enhance cell adhesion and growth surrounding the stent covers without affecting its bulk properties. Plasma polymer (PP) deposition used to create thin films rich in functional groups, e.g. primary amines, known to enhance the cellular response and allow grafting of biomolecules especially on stent grafts. Thin film adhesion to stent polymeric cover should be considered especially as they will evolve in a biological environment. The aim of this project is to evaluate the adhesion of PP on polytetrafluoroethylene (PTFE) and polyethyleneterephthalate (PET). Thereafter, an ammonia plasma treatment on PTFE is performed prior to deposition of PP to optimize the PP/PTFE adhesion. PP studied here (referred to as "LP") is prepared from a mixture of ethylene (C2H4) and ammonia (NH3). It is deposited on two supports, PET and PTFE. The interfacial adhesion between the LP coating and the substrate was evaluated by "Peel-test 180 °" according to ASTM F1842. Staining of the surface after peel test followed by an image analysis was performed to determine the percentage of removed coating. Adhesion optimization is done by varying operating plasma parameters such as power, pressure and pretreatment time. Chemical analyses and wettability of LP and pretreated surfaces in dry and wet conditions are characterized by XPS and contact angle measurements, respectively. The adhesion of LP/PET was excellent in a dry environment (<1%), but lower under wet conditions (4+/-6% and 44+/-7% as minimum and maximum values at 5min and 60min of immersion in deionized water, respectively). However, 56% to 75% of the LP is removed from virgin PTFE in a dry and wet environment, respectively; percentages can be substantially reduced by plasma pretreatment (0% and 8+/-3% in air and 30min in deionized water). Almost no delamination was observed with NH3 plasma pretreatment at 15s, 100 mTorr and 50W. N2 plasma pretreatment, for comparison, proves much less effective. The LP/PTFE adhesion is considerably improved by plasma pretreatment compared to untreated samples. The chemical LP composition and the cell growth on LP/pretreated PTFE are not significantly affected by this pretreatment. Further investigations are required to explain the LP/PET low adhesion in wet conditions.

Compatibility Testing of Polymeric Materials for the Urine Processor Assembly (UPA) of International Space Station (ISS)

NASA Technical Reports Server (NTRS)

Wingard, Charles D.

2003-01-01

In the International Space Station (ISS), astronauts will convert urine into potable water with the Urine Processor Assembly (UPA) by a distillation process. The urine is pre-treated, containing flush water and stabilizers. About 2.5% solids in the urine are concentrated up to 16% brine through distillation. Dynamic mechanical analysis (DMA) in the stress relaxation mode was primarily used to test 15 polymeric UPA materials for compatibility with the pre-treated and brine solutions. There were concerns that chromium trioxide (CrO3), a stabilizer not in the original pre-treat formulation for similar compatibility testing in 2000, could have an adverse effect on these polymers. DMA testing is partially complete for polymeric material samples immersed in the two solutions at room temperature for as long as 200 days. By comparing each material (conditioned and virgin), the stress relaxation modulus (E) was determined for short-term use and predicted for as long as a 10-year use in space. Such a delta E showed a decrease of as much as 79% for a Nylon material, but an increase as much as 454% for a polysulfone material, with increasing immersion time.

Effect of pre-treatment with dichloroacetic or trichloroacetic acid in drinking water on the pharmacokinetics of a subsequent challenge dose in B6C3F1 mice.

PubMed

Gonzalez-Leon, A; Merdink, J L; Bull, R J; Schultz, I R

1999-12-15

Dichloroacetate (DCA) and trichloroacetate (TCA) are prominent by-products of chlorination of drinking water. Both chemicals have been shown to be hepatic carcinogens in mice. Prior work has demonstrated that DCA inhibits its own metabolism in rats and humans. This study focuses on the effect of prior administration of DCA or TCA in drinking water on the pharmacokinetics of a subsequent challenge dose of DCA or TCA in male B6C3F1 mice. Mice were provided with DCA or TCA in their drinking water at 2 g/l for 14 days and then challenged with a 100 mg/kg i.v. (non-labeled) or gavage (14C-labeled) dose of DCA or TCA. The challenge dose was administered after 16 h fasting and removal of the haloacetate pre-treatment. The haloacetate blood concentration-time profile and the disposition of 14C were characterized and compared with controls. The effect of pre-treatment on the in vitro metabolism of DCA in hepatic S9 was also evaluated. Pre-treatment with DCA caused a significant increase in the blood concentration-time profiles of the challenge dose of DCA. No effect on the blood concentration-time profile of DCA was observed after pre-treatment with TCA. Pre-treatment with TCA had no effect on subsequent doses of DCA. Pre-treatment with DCA did not have a significant effect on the formation of 14CO2 from radiolabeled DCA. In vitro experiments with liver S9 from DCA-pre-treated mice demonstrated that DCA inhibits it own metabolism. These results indicate that DCA metabolism in mice is also susceptible to inhibition by prior treatment with DCA, however the impact on clearance is less marked in mice than in F344 rats. In contrast, the metabolism and pharmacokinetics of TCA is not affected by pre-treatment with either DCA or TCA.

Alkaline hydrogen peroxide pretreatment of cashew apple bagasse for ethanol production: study of parameters.

PubMed

Correia, Jessyca Aline da Costa; Júnior, José Edvan Marques; Gonçalves, Luciana Rocha B; Rocha, Maria Valderez Ponte

2013-07-01

The alkaline hydrogen peroxide (AHP) pretreatment of cashew apple bagasse (CAB) was evaluated based on the conversion of the resultant cellulose into glucose. The effects of the concentration of hydrogen peroxide at pH 11.5, the biomass loading and the pretreatment duration performed at 35°C and 250 rpm were evaluated after the subsequent enzymatic saccharification of the pretreated biomass using a commercial cellulase enzyme. The CAB used in this study contained 20.56 ± 2.19% cellulose, 10.17 ± 0.89% hemicellulose and 35.26 ± 0.90% lignin. The pretreatment resulted in a reduced lignin content in the residual solids. Increasing the H2O2 concentration (0-4.3% v/v) resulted in a higher rate of enzymatic hydrolysis. Lower biomass loadings gave higher glucose yields. In addition, no measurable furfural and hydroxymethyl furfural were produced in the liquid fraction during the pretreatment. The results show that alkaline hydrogen peroxide is effective for the pretreatment of CAB. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Effect of sub- and supercritical water treatments on the physicochemical properties of crab shell chitin and its enzymatic degradation.

PubMed

Osada, Mitsumasa; Miura, Chika; Nakagawa, Yuko S; Kaihara, Mikio; Nikaido, Mitsuru; Totani, Kazuhide

2015-12-10

This study examined the effects of sub- and supercritical water pretreatments on the physicochemical properties of crab shell α-chitin and its enzymatic degradation to obtain N,N'-diacetylchitobiose (GlcNAc)2. Following sub- and supercritical water pretreatments, the protein in the crab shell was removed and the residue of crab shell contained α-chitin and CaCO3. Prolonged pretreatment led to α-chitin decomposition. The reaction of pure α-chitin in sub- and supercritical water pretreatments was investigated separately; we observed lower mean molecular weight and weaker hydrogen bonds compared with untreated α-chitin. (GlcNAc)2 yields from enzymatic degradation of subcritical (350 °C, 7 min) and supercritical water (400 °C, 2.5 min) pretreated crab shell were 8% and 6%, compared with 0% without any pretreatment. This study shows that sub- and supercritical water pretreatments of crab shell provide to an alternative method to the use of acid and base for decalcification and deproteinization of crab shell required for (GlcNAc)2 production. Copyright © 2015 Elsevier Ltd. All rights reserved.

Glucose concentration in the blood of intact and alloxan-treated mice after pretreatment with commercial preparations of Stevia rebaudiana (Bertoni).

PubMed

Raskovic, Aleksandar; Gavrilovic, Maja; Jakovljevic, Vida; Sabo, Jan

2004-01-01

The study was concerned with the effect of mice pretreatment with two commercial products of Stevia rebaudiana Bertoni on the blood glucose concentration. One group of mice was pretreated four days with 200 mg/kg of Stevita (Stevita Co, INC, Arlington Texas) (stevia) and the other with 20 mg/kg of Clear Steviosides liquid (Stevita Co, INC, Herbal supplement, Brazil) (stevioside), whereas the animals of control group received at the same time physiological solution. Blood glucose concentration was measured before pretreatment and four days after that. The changes in glucose level were provoked by glucose-tolerance test (500 mg/kg, p.o.) and subcutaneous injection of adrenaline (0.2 mg/kg). The same procedure of measuring blood glucose was applied on the mice with alloxan-induced diabetes mellitus (two doses of 100 mg/kg with a 24-hour interval). Blood glucose levels in mice pretreated with stevia and stevioside were lower compared with control (7.82:6.82:8.01). Also, a smaller increase in this parameter compared to control was registered with pretreated mice in the glucose-tolerance test, pretreatment with stevioside being again more effective (8.68:6.36:5.82). Pretreatment with stevioside caused no significant increase in blood glucose concentration after administering adrenaline, which was not the case with the animals pretreated with stevia and control. Pretreatment with stevia, and to a greater extent with stevioside, protected test animals from the toxic action of alloxan compared with controls.

Sensitizing Effects of Pretreatment Measures on Cancer Chemotherapy Nausea and Vomiting.

ERIC Educational Resources Information Center

Gard, Diane; And Others

1988-01-01

Explored sensitizing effects of pretreatment assessment on posttreatment chemotherapy nausea and vomiting and interactive effects of personal dispositions for information seeking. Oncology patients rated side effects experienced previously (experimental condition), or parking conditions (control). Posttreatment, nausea of experimentals was…

Enhanced thermophilic fermentative hydrogen production from cassava stillage by chemical pretreatments.

PubMed

Wang, Wen; Luo, Gang; Xie, Li; Zhou, Qi

2013-01-01

Acid and alkaline pretreatments for enhanced hydrogen production from cassava stillage were investigated in the present study. The result showed that acid pretreatment was suitable for enhancement of soluble carbohydrate while alkaline pretreatment stimulated more soluble total organic carbon production from cassava stillage. Acid pretreatment thereby has higher capacity to promote hydrogen production compared with alkaline pretreatment. Effects of pretreatment temperature, time and acid concentration on hydrogen production were also revealed by response surface methodology. The results showed that the increase of all factors increased the soluble carbohydrate production, whereas hydrogen production was inhibited when the factors exceeded their optimal values. The optimal conditions for hydrogen production were pretreatment temperature 89.5 °C, concentration 1.4% and time 69 min for the highest hydrogen production of 434 mL, 67% higher than raw cassava stillage.

The effects of MDMA pretreatment on the behavioural effects of other drugs of abuse in the rat elevated plus-maze test.

PubMed

Sumnall, H R; O'Shea, E; Marsden, C A; Cole, J C

2004-04-01

Few preclinical studies have found long-term behavioural consequences of the serotonergic neurotoxicity produced by 3,4-methylenedioxymethamphetamine (MDMA). This study investigated whether pretreatment with MDMA altered the behavioural effects of other drugs of abuse. Adult male Lister hooded rats (n=10/group) were pretreated with 10 mg/kg MDMA or 1 ml/kg saline vehicle intraperitoneally every 2 h for 6 h. Fourteen days later, the behavioural effects of d-amphetamine (2 mg/kg), cocaine (10 mg/kg), ethanol (2.0 g/kg), heroin (0.5 mg/kg), or MDMA (10 mg/kg) were assessed in the elevated plus-maze test. MDMA pretreatment produced approximately 20-25% decrease in hippocampal 5-HT and 5-HIAA concentrations, and [(3)H]paroxetine binding when analysed 2 weeks later. Despite inducing neurotoxicity, this regimen had no effect upon the plus-maze behaviour induced by ethanol, heroin, and MDMA. Acutely, and independent of neurotoxic pretreatment, MDMA produced a clear anxiogenic-like behavioural profile with a reduction of open arm entries and suppression of explorative behaviours. Despite being acutely anxiogenic, pretreatment with a neurotoxic regimen of MDMA has little effect on the anxiety-related effects of other drugs of abuse. It is possible that extended time points would produce significant changes, although the available evidence suggests that the plus-maze may not be a suitable model for detection of behavioural dysfunction after neurotoxic MDMA.

Dissociation of the neurochemical and behavioral toxicology of MDMA ('Ecstasy') by citalopram.

PubMed

Piper, Brian J; Fraiman, Joseph B; Owens, Cullen B; Ali, Syed F; Meyer, Jerrold S

2008-04-01

High or repeated doses of the recreational drug 3,4-methylenedioxymethamphetamine (MDMA, or 'Ecstasy') produce long-lasting deficits in several markers of serotonin (5-HT) system integrity and also alter behavioral function. However, it is not yet clear whether MDMA-induced serotonergic neurotoxicity is responsible for these behavioral changes or whether other mechanisms are involved. The present experiment tested the hypothesis that blocking serotonergic neurotoxicity by pretreatment with the selective 5-HT reuptake inhibitor citalopram will also prevent the behavioral and physiological consequences of an MDMA binge administration. Male, Sprague-Dawley rats (N=67) received MDMA (4 x 10 mg/kg) with or without citalopram (10 mg/kg) pretreatment. Core temperature, ejaculatory response, and body weight were monitored during and immediately following drug treatments. A battery of tests assessing motor, cognitive, exploratory, anxiety, and social behaviors was completed during a 10-week period following MDMA administration. Brain tissue was collected at 1 and 10 weeks after drug treatments for measurement of regional 5-HT transporter binding and (for the 1-week samples) 5-HT and 5-HIAA concentrations. Citalopram pretreatment blocked MDMA-related reductions in aggressive and exploratory behavior measured in the social interaction and hole-board tests respectively. Such pretreatment also had the expected protective effect against MDMA-induced 5-HT neurotoxicity at 1 week following the binge. In contrast, citalopram did not prevent most of the acute effects of MDMA (eg hyperthermia and weight loss), nor did it block the decreased motor activity seen in the binge-treated animals 1 day after dosing. These results suggest that some of the behavioral and physiological consequences of a high-dose MDMA regimen in rats are mediated by mechanisms other than the drug's effects on the serotonergic system. Elucidation of these mechanisms requires further study of the influence of MDMA on other neurotransmitter systems.

Influence of feedstock particle size on lignocellulose conversion--a review.

PubMed

Vidal, Bernardo C; Dien, Bruce S; Ting, K C; Singh, Vijay

2011-08-01

Feedstock particle sizing can impact the economics of cellulosic ethanol commercialization through its effects on conversion yield and energy cost. Past studies demonstrated that particle size influences biomass enzyme digestibility to a limited extent. Physical size reduction was able to increase conversion rates to maximum of ≈ 50%, whereas chemical modification achieved conversions of >70% regardless of biomass particle size. This suggests that (1) mechanical pretreatment by itself is insufficient to attain economically feasible biomass conversion, and, therefore, (2) necessary particle sizing needs to be determined in the context of thermochemical pretreatment employed for lignocellulose conversion. Studies of thermochemical pretreatments that have taken into account particle size as a factor have exhibited a wide range of maximal sizes (i.e., particle sizes below which no increase in pretreatment effectiveness, measured in terms of the enzymatic conversion resulting from the pretreatment, were observed) from <0.15 to 50 mm. Maximal sizes as defined above were dependent on the pretreatment employed, with maximal size range decreasing as follows: steam explosion > liquid hot water > dilute acid and base pretreatments. Maximal sizes also appeared dependent on feedstock, with herbaceous or grassy biomass exhibiting lower maximal size range (<3 mm) than woody biomass (>3 mm). Such trends, considered alongside the intensive energy requirement of size reduction processes, warrant a more systematic study of particle size effects across different pretreatment technologies and feedstock, as a requisite for optimizing the feedstock supply system.

Power ultrasound as a pretreatment to convective drying of mulberry (Morus alba L.) leaves: Impact on drying kinetics and selected quality properties.

PubMed

Tao, Yang; Wang, Ping; Wang, Yilin; Kadam, Shekhar U; Han, Yongbin; Wang, Jiandong; Zhou, Jianzhong

2016-07-01

The effect of ultrasound pretreatment prior to convective drying on drying kinetics and selected quality properties of mulberry leaves was investigated in this study. Ultrasound pretreatment was carried out at 25.2-117.6 W/L for 5-15 min in a continuous mode. After sonication, mulberry leaves were dried in a hot-air convective dryer at 60 °C. The results revealed that ultrasound pretreatment not only affected the weight of mulberry leaves, it also enhanced the convective drying kinetics and reduced total energy consumption. The drying kinetics was modeled using a diffusion model considering external resistance and effective diffusion coefficient De and mass transfer coefficient hm were identified. Both De and hm during convective drying increased with the increase of acoustic energy density (AED) and ultrasound duration. However, De and hm increased slowly at high AED levels. Furthermore, ultrasound pretreatment had a more profound influence on internal mass transfer resistance than on external mass transfer resistance during drying according to Sherwood numbers. Regarding the quality properties, the color, antioxidant activity and contents of several bioactive compounds of dried mulberry leaves pretreated by ultrasound at 63.0 W/L for 10 min were similar to that of mulberry leaves without any pretreatments. Overall, ultrasound pretreatment is effective to shorten the subsequent drying time of mulberry leaves without damaging the quality of final product. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of silane pretreatment on the immediate bonding of universal adhesives to computer-aided design/computer-aided manufacturing lithium disilicate glass ceramics.

PubMed

Yao, Chenmin; Zhou, Liqun; Yang, Hongye; Wang, Yake; Sun, Hualing; Guo, Jingmei; Huang, Cui

2017-04-01

The aim of this study was to investigate the effect of silane pretreatment on the universal adhesive bonding between lithium disilicate glass ceramic and composite resin. IPS e.max ceramic blocks etched with hydrofluoric acid were randomly assigned to one of eight groups treated with one of four universal adhesives (two silane-free adhesives and two silane-containing adhesives), each with or without silane pretreatment. Bonded specimens were stored in water for 24 h. The shear bond strength (SBS) of the ceramic-resin interface was measured to evaluate bond strength, and the debonded interface after the SBS test was analysed using field-emission scanning electron microscopy to determine failure mode. Light microscopy was performed to analyse microleakage and marginal sealing ability. Silane pretreatment significantly and positively influenced SBS and marginal sealing ability. For all the universal adhesive groups, SBS increased and the percentage of microleakage decreased after the pretreatment. Without the pretreatment, SBS and the percentage of microleakage were not significantly different between the silane-containing universal adhesive groups and the silane-free groups. Cohesive failure was the main fracture pattern. The results suggest that additional silane pretreatment can effectively improve the bonding strength and marginal sealing of adhesives to lithium disilicate glass ceramics. The bonding performance of silane-containing universal adhesives without pretreatment is similar to that of silane-free adhesives. © 2017 Eur J Oral Sci.

Dialectical behavior therapy (DBT) applied to college students: a randomized clinical trial.

PubMed

Pistorello, Jacqueline; Fruzzetti, Alan E; Maclane, Chelsea; Gallop, Robert; Iverson, Katherine M

2012-12-01

College counseling centers (CCCs) are increasingly being called upon to treat highly distressed students with complex clinical presentations. This study compared the effectiveness of Dialectical Behavior Therapy (DBT) for suicidal college students with an optimized control condition and analyzed baseline global functioning as a moderator. The intent-to-treat (ITT) sample included 63 college students between the ages of 18 and 25 years who were suicidal at baseline, reported at least 1 lifetime nonsuicidal self-injurious (NSSI) act or suicide attempt, and met 3 or more borderline personality disorder (BPD) diagnostic criteria. Participants were randomly assigned to DBT (n = 31) or an optimized treatment-as-usual (O-TAU) control condition (n = 32). Treatment was provided by trainees, supervised by experts in both treatments. Both treatments lasted 7-12 months and included both individual and group components. Assessments were conducted at pretreatment, 3 months, 6 months, 9 months, 12 months, and 18 months (follow-up). Mixed effects analyses (ITT sample) revealed that DBT, compared with the control condition, showed significantly greater decreases in suicidality, depression, number of NSSI events (if participant had self-injured), BPD criteria, and psychotropic medication use and significantly greater improvements in social adjustment. Most of these treatment effects were observed at follow-up. No treatment differences were found for treatment dropout. Moderation analyses showed that DBT was particularly effective for suicidal students who were lower functioning at pretreatment. DBT is an effective treatment for suicidal, multiproblem college students. Future research should examine the implementation of DBT in CCCs in a stepped care approach.

Neural network detects the effects of p-CPA pre-treatment on brain electrophysiology in a rat model of focal brain injury.

PubMed

Sinha, Rakesh Kumar; Aggarwal, Yogender

2009-04-01

To examine the performance of Artificial Neural Network (ANN) in evaluation of the effects of pretreatment of para-Chlorophenylalanine (p-CPA), a serotonin blocker, in experimental brain injury. Continuous 4 h digital electroencephalogram (EEG) recordings from male Charles Foster rats and its power spectrum analysis by using fast Fourier transform (FFT) were performed in two experimental (i) drug untreated injury group; (ii) p-CPA pretreated injury group as well as a control group. The EEG power spectrum data were tested by ANN containing 60 nodes in input layer, weighted from the digital values of power spectrum from 0 to 30 Hz, 18 nodes in hidden layer and an output node. The effects of injury and of the drug pretreatment were confirmed with the help of calculation of edematous swelling in the brain. The changes in EEG spectral patterns were compared with the ANN and the accuracy was determined in terms of percent (%). Overall performance of the network was found the best in control group (97.9%) in comparison to p-CPA untreated injury group (96.3%) and p-CPA pretreated injury group (71.9%). The decrease in accuracy in p-CPA pretreated injury group of subjects have occurred due to increase in misclassified patterns due to faster recovery in brain cortical potentials. EEG spectrum analysis with ANN was found successful in identifying the changes due to brain swelling as well as the effect of pretreatment of p-CPA in focal brain injury condition. Thus, the training and testing of ANN with EEG power spectra can be used as an effective diagnostic tool for early prediction and monitoring of brain injury as well as the effects of drugs in this condition.

The effectiveness of pretreatment physics plan review for detecting errors in radiation therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gopan, Olga; Zeng, Jing; Novak, Avrey

Purpose: The pretreatment physics plan review is a standard tool for ensuring treatment quality. Studies have shown that the majority of errors in radiation oncology originate in treatment planning, which underscores the importance of the pretreatment physics plan review. This quality assurance measure is fundamentally important and central to the safety of patients and the quality of care that they receive. However, little is known about its effectiveness. The purpose of this study was to analyze reported incidents to quantify the effectiveness of the pretreatment physics plan review with the goal of improving it. Methods: This study analyzed 522 potentiallymore » severe or critical near-miss events within an institutional incident learning system collected over a three-year period. Of these 522 events, 356 originated at a workflow point that was prior to the pretreatment physics plan review. The remaining 166 events originated after the pretreatment physics plan review and were not considered in the study. The applicable 356 events were classified into one of the three categories: (1) events detected by the pretreatment physics plan review, (2) events not detected but “potentially detectable” by the physics review, and (3) events “not detectable” by the physics review. Potentially detectable events were further classified by which specific checks performed during the pretreatment physics plan review detected or could have detected the event. For these events, the associated specific check was also evaluated as to the possibility of automating that check given current data structures. For comparison, a similar analysis was carried out on 81 events from the international SAFRON radiation oncology incident learning system. Results: Of the 356 applicable events from the institutional database, 180/356 (51%) were detected or could have been detected by the pretreatment physics plan review. Of these events, 125 actually passed through the physics review; however, only 38% (47/125) were actually detected at the review. Of the 81 events from the SAFRON database, 66/81 (81%) were potentially detectable by the pretreatment physics plan review. From the institutional database, three specific physics checks were particularly effective at detecting events (combined effectiveness of 38%): verifying the isocenter (39/180), verifying DRRs (17/180), and verifying that the plan matched the prescription (12/180). The most effective checks from the SAFRON database were verifying that the plan matched the prescription (13/66) and verifying the field parameters in the record and verify system against those in the plan (23/66). Software-based plan checking systems, if available, would have potential effectiveness of 29% and 64% at detecting events from the institutional and SAFRON databases, respectively. Conclusions: Pretreatment physics plan review is a key safety measure and can detect a high percentage of errors. However, the majority of errors that potentially could have been detected were not detected in this study, indicating the need to improve the pretreatment physics plan review performance. Suggestions for improvement include the automation of specific physics checks performed during the pretreatment physics plan review and the standardization of the review process.« less

The effectiveness of pretreatment physics plan review for detecting errors in radiation therapy.

PubMed

Gopan, Olga; Zeng, Jing; Novak, Avrey; Nyflot, Matthew; Ford, Eric

2016-09-01

The pretreatment physics plan review is a standard tool for ensuring treatment quality. Studies have shown that the majority of errors in radiation oncology originate in treatment planning, which underscores the importance of the pretreatment physics plan review. This quality assurance measure is fundamentally important and central to the safety of patients and the quality of care that they receive. However, little is known about its effectiveness. The purpose of this study was to analyze reported incidents to quantify the effectiveness of the pretreatment physics plan review with the goal of improving it. This study analyzed 522 potentially severe or critical near-miss events within an institutional incident learning system collected over a three-year period. Of these 522 events, 356 originated at a workflow point that was prior to the pretreatment physics plan review. The remaining 166 events originated after the pretreatment physics plan review and were not considered in the study. The applicable 356 events were classified into one of the three categories: (1) events detected by the pretreatment physics plan review, (2) events not detected but "potentially detectable" by the physics review, and (3) events "not detectable" by the physics review. Potentially detectable events were further classified by which specific checks performed during the pretreatment physics plan review detected or could have detected the event. For these events, the associated specific check was also evaluated as to the possibility of automating that check given current data structures. For comparison, a similar analysis was carried out on 81 events from the international SAFRON radiation oncology incident learning system. Of the 356 applicable events from the institutional database, 180/356 (51%) were detected or could have been detected by the pretreatment physics plan review. Of these events, 125 actually passed through the physics review; however, only 38% (47/125) were actually detected at the review. Of the 81 events from the SAFRON database, 66/81 (81%) were potentially detectable by the pretreatment physics plan review. From the institutional database, three specific physics checks were particularly effective at detecting events (combined effectiveness of 38%): verifying the isocenter (39/180), verifying DRRs (17/180), and verifying that the plan matched the prescription (12/180). The most effective checks from the SAFRON database were verifying that the plan matched the prescription (13/66) and verifying the field parameters in the record and verify system against those in the plan (23/66). Software-based plan checking systems, if available, would have potential effectiveness of 29% and 64% at detecting events from the institutional and SAFRON databases, respectively. Pretreatment physics plan review is a key safety measure and can detect a high percentage of errors. However, the majority of errors that potentially could have been detected were not detected in this study, indicating the need to improve the pretreatment physics plan review performance. Suggestions for improvement include the automation of specific physics checks performed during the pretreatment physics plan review and the standardization of the review process.

The effects of cathodic micro-voltage combined with hydrothermal pretreatment on methane fermentation of lignocellulose substrate

NASA Astrophysics Data System (ADS)

Liu, Dianxin; Ning, Ping; Qu, Guangfei; Huang, Xi; Liu, Yuhuan; Zhang, Jian

2017-05-01

The methane fermentation study assisted with cathodic micro-voltage was carried out to investigate the electric field effects on the fermentation of hydrothermally pretreated lignocellulose substrate. It was illustrated that a 0.25V cathode voltage and hydrothermal pretreatment could improve the biogas production, biogas quality and lignocellulose degradation ratio significantly. The cumulative biogas productions in the fermentation of hydrothermally pretreated cow dungs at 50°C, 150°C and 200°C with a 0.25V cathode voltage were observed in a total of 6640mL, 9218mL and 9456mL respectively over a detention time of 33 days. In comparison with the fermentation pretreated at 200°C without any voltage, nearly doubled of cumulative biogas production was obtained in the process of cathode-assisted fermentation. It was also observed that the daily methane content greater than or equal to 70% in the biogas generated with cathode voltage were clearly greater than that without voltages. Furthermore, the fermentation applied with a 0.25V cathode voltage had resulted into significant increases of 12.64% and 9.44% in lignin and cellulose degradation ratio relative to voltage free fermentation. And in the process of fermentation applied with cathode voltage, the final lignocellulose degradation ratio increased with the hydrothermal pretreatment temperature. Thus, the hydrothermal pretreatment and assisting fermentation with low cathode voltage can effectively promote the lignocellulose degradation. All results revealed that cathodic micro-voltage combined with hydrothermal pretreatment can remarkably improve the fermentation of lignocellulosic materials, indicating that a more effective fermentation technology can be developed by applying with cathodic micro-voltage.

Effect of EDTA and phosphoric Acid pretreatment on the bonding effectiveness of self-etch adhesives to ground enamel.

PubMed

Ibrahim, Ihab M; Elkassas, Dina W; Yousry, Mai M

2010-10-01

This in vitro study determined the effect of enamel pretreatment with phosphoric acid and ethylenediaminetetraacetic acid (EDTA) on the bond strength of strong, intermediary strong, and mild self-etching adhesive systems. Ninety sound human premolars were used. Resin composite cylinders were bonded to flat ground enamel surfaces using three self-etching adhesive systems: strong Adper Prompt L-Pop (pH=0.9-1.0), intermediary strong AdheSE (pH=1.6-1.7), and mild Frog (pH=2). Adhesive systems were applied either according to manufacturer instructions (control) or after pretreatment with either phosphoric acid or EDTA (n=10). After 24 hours, shear bond strength was tested using a universal testing machine at a cross-head speed of 0.5 mm/minute. Ultra-morphological characterization of the surface topography and resin/enamel interfaces as well as representative fractured enamel specimens were examined using scanning electron microscopy (SEM). Neither surface pretreatment statistically increased the mean shear bond strength values of either the strong or the intermediary strong self-etching adhesive systems. However, phosphoric acid pretreatment significantly increased the mean shear bond strength values of the mild self-etching adhesive system. SEM examination of enamel surface topography showed that phosphoric acid pretreatment deepened the same etching pattern of the strong and intermediary strong adhesive systems but converted the irregular etching pattern of the mild self-etching adhesive system to a regular etching pattern. SEM examination of the resin/enamel interface revealed that deepening of the etching pattern was consistent with increase in the length of resin tags. EDTA pretreatment had a negligible effect on ultra-morphological features. Use of phosphoric acid pretreatment can be beneficial with mild self-etching adhesive systems for bonding to enamel.

Effect of EDTA and Phosphoric Acid Pretreatment on the Bonding Effectiveness of Self-Etch Adhesives to Ground Enamel

PubMed Central

Ibrahim, Ihab M.; Elkassas, Dina W.; Yousry, Mai M.

2010-01-01

Objectives: This in vitro study determined the effect of enamel pretreatment with phosphoric acid and ethylenediaminetetraacetic acid (EDTA) on the bond strength of strong, intermediary strong, and mild self-etching adhesive systems. Methods: Ninety sound human premolars were used. Resin composite cylinders were bonded to flat ground enamel surfaces using three self-etching adhesive systems: strong Adper Prompt L-Pop (pH=0.9–1.0), intermediary strong AdheSE (pH=1.6–1.7), and mild Frog (pH=2). Adhesive systems were applied either according to manufacturer instructions (control) or after pretreatment with either phosphoric acid or EDTA (n=10). After 24 hours, shear bond strength was tested using a universal testing machine at a cross-head speed of 0.5 mm/minute. Ultra-morphological characterization of the surface topography and resin/enamel interfaces as well as representative fractured enamel specimens were examined using scanning electron microscopy (SEM). Results: Neither surface pretreatment statistically increased the mean shear bond strength values of either the strong or the intermediary strong self-etching adhesive systems. However, phosphoric acid pretreatment significantly increased the mean shear bond strength values of the mild self-etching adhesive system. SEM examination of enamel surface topography showed that phosphoric acid pretreatment deepened the same etching pattern of the strong and intermediary strong adhesive systems but converted the irregular etching pattern of the mild self-etching adhesive system to a regular etching pattern. SEM examination of the resin/enamel interface revealed that deepening of the etching pattern was consistent with increase in the length of resin tags. EDTA pretreatment had a negligible effect on ultra-morphological features. Conclusions: Use of phosphoric acid pretreatment can be beneficial with mild self-etching adhesive systems for bonding to enamel. PMID:20922162

Quantification and characterisation of fatty acid methyl esters in microalgae: Comparison of pretreatment and purification methods.

PubMed

Lage, Sandra; Gentili, Francesco G

2018-06-01

A systematic qualitative and quantitative analysis of fatty acid methyl esters (FAMEs) is crucial for microalgae species selection for biodiesel production. The aim of this study is to identify the best method to assess microalgae FAMEs composition and content. A single-step method, was tested with and without purification steps-that is, separation of lipid classes by thin-layer chromatography (TLC) or solid-phase extraction (SPE). The efficiency of a direct transesterification method was also evaluated. Additionally, the yield of the FAMEs and the profiles of the microalgae samples with different pretreatments (boiled in isopropanol, freezing, oven-dried and freeze-dried) were compared. The application of a purification step after lipid extraction proved to be essential for an accurate FAMEs characterisation. The purification methods, which included TLC and SPE, provided superior results compared to not purifying the samples. Freeze-dried microalgae produced the lowest FAMEs yield. However, FAMEs profiles were generally equivalent among the pretreatments. Copyright © 2018 Elsevier Ltd. All rights reserved.