• Journal of Chest Surgery
• /
• v.44 no.2
• /
• pp.99-107
• /
• 2011

Background: Calcification is the most frequent cause of clinical failure of bioprosthetic tissues fabricated from GA-fixed porcine valves or bovine pericardium. A multi-factorial approach using different mechanisms was recently developed to reduce the calcification of bioprosthetic tissues. The purpose of the present study was to evaluate the synchronized synergism of using L-arginine and $NaBH_4$, compared with ethanol and L-lysine, in glutaraldehyde treated porcine pericardium from the standpoint of calcification and tissue elasticity. Materials and Methods: Porcine pericardium was fixed at 0.625% GA (7 days at room temperature after 2 days at $4^{\circ}C$). An interim step of ethanol (80%; 1 day at room temperature) or L-lysine (0.1 M; 2 days at $37^{\circ}C$) or L-arginine (0.1 M; 2 days at $37^{\circ}C$) was followed by completion of the GA fixation. A final step of NaBH4 (0.1 M; 2 days at room temperature) was followed. Their tensile strength, thickness, and thermal stability were measured. Treated pericardia were implanted subcutaneously into three-week-old Sprague-Dawley rats for 8 weeks. Calcium content was assessed by atomic absorption spectroscopy and histology. Results: L-arginine and $NaBH_4$ pretreatment ($1.81{\pm}0.39$ kgf/5 mm p=0.001, $0.30{\pm}0.08$ mm p<0.001) significantly increased tensile strength and thickness compared with the control ($0.53{\pm}0.34$ kgf/5 mm, $0.10{\pm}0.02$ mm). In a thermal stability test, L-arginine and $NaBH_4$ pretreatment ($84.25{\pm}1.12^{\circ}C$, p=0.023) caused a significant difference from the control ($86.25{\pm}0.00^{\circ}C$). L-lysine and $NaBH_4$ pretreatment ($183.8{\pm}42.6$ ug/mg, p=0.804), and L-arginine and $NaBH_4$ pretreatment ($163.3{\pm}27.5$ ug/mg, p=0.621) did not significantly inhibit calcification compared to the control ($175.5{\pm}45.3$ ug/mg), but ethanol and $NaBH_4$ pretreatment did ($38.5{\pm}37.3$ ug/mg, p=0.003). Conclusion: The combined pretreatment using L-arginine and $NaBH_4$ after GA fixation seemed to increase the tensile strength and thickness of porcine pericardium, fixed with GA. Additionally, it seemed to keep thermal stability. However it could not decrease the calcification of porcine pericardium fixed with GA. $NaBH_4$ pretreatment seemed to decrease the calcification of porcine pericardium fixed with GA, but only with ethanol.

• Membrane and Water Treatment
• /
• v.3 no.4
• /
• pp.253-266
• /
• 2012

In this work, the effect of hybrid salts precipitation-nanofiltration (SP-NF) process on the scale deposits in thermal and membrane desalination processes has been studied. The analysis was carried out to study the scale formation from the Arabian Gulf seawater in MSF and RO reference processes by changing the percentage of pretreatment from 0 to 100%. Four different SP-NF configurations were suggested. A targeted Top Brine Temperature (TBT) of $130^{\circ}C$ may be achieved if 30% portion is pretreated by SP and/or NF processes. As a rule of thumb, each 1% pretreatment portion increases the reference TBT of $115^{\circ}C$ by $0.6^{\circ}C$. For both MSF and RO, parallel pretreatment of certain percentage of the feed by SP and the rest by NF, showed the lowest scale values. The case showed the best values for sulfate scale prevention and the highest values of increasing the monovalent ions relative to the divalent scale forming ions. Sulfate scale is significant in MSF process while carbonate scale is significant in RO. Salt precipitation was suggested because it is less costly than nanofiltration, but nanofiltration was used here because it is efficient in sulfate ions removal.

• Journal of Korean Society of Environmental Engineers
• /
• v.33 no.4
• /
• pp.237-242
• /
• 2011

In this study, the catalytic activity of Mn-Phthalocyanine (Mn-PC) for VOCs (acetadehyde, propionaldehyde and toluene) combustion was determined. The reaction was carried out in a fixed bed reactor at the temperature range of $200{\sim}380^{\circ}C$. We investigated the physicochemical properties of Mn-PC before and after the pretreatment (air, $450^{\circ}C$, 1 hr, 60 cc/min) by TGA (Thermogravimetric Analyzer), BET (Brunauer Emmett Teller), EA (Elemental Analyzer), XRD (X-ray Diffractometer) and SEM (Scanning Electronic Microscope). By TGA analysis, 88 wt.% mass loss of Mn-PC was found at $419^{\circ}C$. The BET surface area of Mn-PC increased after the pretreatment. The decomposition and combustion of organic components in Mn-PC were observed by EA analysis. We also confirmed that Mn-PC had transformed into a new manganese oxide phase ($Mn_3O_4$) after the pretreatment by XRD analysis. By SEM analysis, many of the micropores generated during the pretreatment were found. The catalytic activity of Mn-PC with the pretreatment for propionaldehyde combustion was higher than that of $Mn_3O_4$ and fresh Mn-PC. It showed the catalytic activity of Mn-PC with the pretreatment for VOCs combustion by the order of toluene < acetadehyde < propionaldehyde.

• Food Science and Preservation
• /
• v.23 no.2
• /
• pp.155-161
• /
• 2016

This study aimed to investigate the effects of pretreatments blanching, roasting, drying, and storage temperatures ($25^{\circ}C$, $4^{\circ}C$ and $-10^{\circ}C$) on their quality of lotus leaves. As a result, the lotus leaves retained a good appearance when stored at $25^{\circ}C$ for 5 days, $4^{\circ}C$ for 30 days, and $-10^{\circ}C$ for 90 days, regardless of the pretreatment used. At the same storage temperatures, pH, soluble solids, total acid content, polyphenols, and microorganisms were significantly different among the pretreatments (p<0.05). Soluble solids, pH, and total acid contents were not significantly different for the same pretreatments at different storage temperatures. However, the polyphenol, oxalic acid, and tartaric acid contents of lotus leaves were significantly different after drying and blanching treatments. In particular, it was shown that polyphenol content of the lotus leaf was affected by both pretreatment and storage temperature. In conclusion, the lotus leaves appeared in good condition until 5 days at $25^{\circ}C$, 30 days at $4^{\circ}C$, and 90 days at $-10^{\circ}C$, regardless of the pretreatment while influenced by storage temperature.

• Journal of the Microelectronics and Packaging Society
• /
• v.22 no.4
• /
• pp.57-63
• /
• 2015

In order to prepare a low-cost conductive filler material possessing improved anti-oxidation property, Ag-coated Cu flakes were fabricated and the effects of an applying method of ammonium-based pretreatment solution on the Cu flakes were analyzed. The pretreatment solution was used to remove the surface oxide layer on Cu flake. During a single-stage pretreatment process, hole-shaped defects were formed on the flake surface during the pretreatment after 2 min, and the number and size increased in proportion to the pretreatment time. In the case that Ag plating solution was injected in the pretreatment solution after the pretreatment for 2 min, the defects were also formed during Ag plating. In contrast, the defects tremendous decreased in the case that the pretreatment solution was removed after the first pretreatment for 2 min and the Ag plating proceeded after the second pretratment using a low concentration pretreatment solution. As the final result, the 15 wt% Ag-coated Cu flake sample which was fabricated using the single-stage pretreatment oxidized at $166^{\circ}C$, but the sample fabricated by the double-stage pretreatment oxidized at $224^{\circ}C$, indicating definitely improved anti-oxidation property.

• Asian Journal of Turfgrass Science
• /
• v.19 no.2
• /
• pp.125-130
• /
• 2005

The effects of various pretreatment in Zoysia japonica are summarized as follows: Seeds that were treated for 7 days in $4^{circ}$C showed a little higher germination rates than those that were treated 3 days in $4^{circ}$C and for 1 day, 3 days in $-20^{circ}$C. Germination rates of the seeds that were soaked in NaOC1 showed higher germination rates than control group. BA 0.1 mg$\cdot$$L^{-1}$ treatment showed a little higher germination than GA3 0.1 mg$\cdot$$L^{-1}$, NAA 0.1 mg$\cdot$$L^{-1}$. Seed germination rates increased around $20^{circ}$C when the samples treated by BA and scarification. Leaf morphological didn't different between control and pretreatment groups.

• Journal of the Korean Wood Science and Technology
• /
• v.43 no.5
• /
• pp.578-590
• /
• 2015

The present study examines the influence of slurry composting and biofiltration liquid fertilizer (SCBLF) treatment on the biomass characteristics of yellow poplar, and the optimization of organosolv pretreatment for sugar production. After SCBLF treatment, total exchangeable cation contents of yellow poplar was increased from $3.1g\;kg^{-1}$ to $4.4g\;kg^{-1}$, and as a result, biomass production of yellow poplar was also enhanced by 82.3%. Organosolv pretreatment was conducted with three independent variables: 1) reaction temperature: $133.2^{\circ}C$ to $166.8^{\circ}C$; 2) acid concentration: 0.2% to 1.8%; and 3) reaction time: 1.6 min to 18.4 min. Reaction temperature was the most significant variable in water insoluble solid (WIS) recovery rate. High overall sugar yield was attained from pretreatment conditions approximately 50% of WIS recovery rate, and the highest overall glucose yield (44.0%) was achieved from pretreatment at $140^{\circ}C$ with 1.5% acid concentration for 5 min. Consequently, 21.1% of glucose and 5.8% of xylose were produced from the organosolv pretreatment of SCBLF-treated 8-year-old yellow poplar.

• Applied Biological Chemistry
• /
• v.41 no.3
• /
• pp.228-233
• /
• 1998

The storage life of satsuma mandarin(Citrus unshiu Marc. var. miyagawa) by the various pretreatment of temperatures; non-treated, room temperature, $10,\;20^{\circ}C$ and $35^{\circ}C$ were investigated. The pretreated citrus fruits were stored at $4^{\circ}C$, 85% relative humidity. Weight loss of citrus fruits by the pretreatment at $35^{\circ}C$ for 24 hrs was the lowest among that of others. Decay ratio of $35^{\circ}C$ pretreated fruits was increased at initial stages of storage, but was maintained low level after that, compared to other treatments. After 115 days storage, firmness of fruits was lowered by the softening, and decayed fruits were occurred increasingly. Ethylene evolution was increased between $55{\sim}65$ days after storage, and the amount was increasing rapidly after 115 days. It seemed to be derived from decayed fruits and physiological activities. $CO_2$ content in fruit was decreased at initial stages of storage, but was increased between $55{\sim}100$ days during storage periods. Acid content, soluble solids, total sugar and vitamin C were reduced gradually during cold storage, but the difference among treatments was not so great. Pretreated fruits at $35^{\circ}C$ for 24 hrs before cold storage was effective on preventing from weight loss and respiration ratio. Optimum storage period of early variety of Satuma mandarin was regarded for 100 days on the basis of appeareance and taste.

• Journal of the Korean Wood Science and Technology
• /
• v.43 no.3
• /
• pp.344-354
• /
• 2015

To investigate the effects of ionic liquid pretreatment on biomass, giant miscanthus was treated with 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) and 1-butyl-3-methylimidazolium acetate ([Bmim][OAc]) at three temperature conditions ($90^{\circ}C$, $110^{\circ}C$, and $130^{\circ}C$). As temperature condition increased, yield of the cellulose-rich product (CP) was reduced from 87.2% to 67.6%, while yield of the ionic liquid lignin (ILL) increased from 2.2% to 9.9%. Compared to the ILL, CP had lower carbon contents and higher oxygen contents. Enzymatic hydrolysis of CPs showed that conversion ratio of CP treated with [Emim][OAc] at $110^{\circ}C$ was 56.7%, the highest digestibility. Thermogravimetric analysis indicated that the maximum degradation rate decreased as temperature condition increased. In addition, maximum degradation temperature of ILL treated with [Emim][OAc] ranged from 274 to $279^{\circ}C$ which was lower than that of ILL treated with [Bmim][OAc]. Analytical date for ${\beta}$-O-4 linkage frequency in the ILL revealed that ${\beta}$-O-4 linkage frequency in the ILL decreased as the temperature rose. Furthermore, the highest S/G ratio of the ILL was determined to ca. 1.2 obtained from [Bmim][OAc] treatment at $110^{\circ}C$.

• KSBB Journal
• /
• v.24 no.6
• /
• pp.527-532
• /
• 2009

Lignocellulose represents a key sustainable source of biomass for transformation into biofuels and bio-based products. Unfortunately, lignocellulosic biomass is highly recalcitrant to biotransformation, both microbial and enzymatic, which limits its use and prevents. As a result, effective pretreatment strategies are necessary. The vast majority of pretreatment strategies have focused on achieving a reduction of lignin content. In this work, an ethanosolv pretreatment has been evaluated for extracting lignin from barley straw. 75% ethanol was used as a pretreatment solvent to extract lignin from barley straw. The influence on delignification of three independent variables are temperature, time, catalyst (1 M $H_2SO_4$) dose. The best pretreatment condition observed was $180^{\circ}C$, 120 min, 0.2% $H_2SO_4$ and delignification was 38%. A combined roasting and ethanosolv, 2-step pretreatment, was developed in order to improve the delignification. Roasting didn't increase the delignification but reduced the pretreatment time. X-ray diffraction results indicated that these physical changes enhance the enzymatic digestibility in the ethanosolv treated barley straw. The cellulose in the pretreated barley straw becomes more crystalline without undergoing ethanosolv.