• Membrane Journal
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• v.31 no.1
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• pp.16-34
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• 2021

Water supplies are decreasing in comparison to increasing clean water demands. Using nanofiltration is one of the most effective and economical methods to meet the need for clean water. Common methods for desalination are reverse osmosis and nanofiltration. However, pristine membranes lack the essential features which are, stability, economic efficiency, antibacterial and antifouling performances. To enhance the properties of the pristine membranes, graphene oxide (GO) is a promising and widely researched material for thin film composites (TFC) membrane due to their characteristics that help improve the hydrophilicity and anti-fouling properties. Modification of the membrane can be done on different layers. The thin film composite membranes are composed of three different layers, the top filtering active thin polyamide (PA) layer, supporting porous layer, and supporting fabric. Forward osmosis (FO) process is yet another energy efficient desalination process, but its efficiency is affected due to biofouling. Incorporation of GO enhance antibacterial properties leading to reduction of biofilm formation on the membrane surface. Pressure retarded osmosis (PRO) is an excellent process to generate clean energy from sea water and the biofouling of membrane is reduced by introduction of GO into the active layer of the TFC membrane. Different modifications on the membranes are being researched, each modification with its own advantages and disadvantages. In this review, modifications of nanofiltration membranes and their composites, characterization, and performances are discussed.

• Biomedical Science Letters
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• v.2 no.2
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• pp.133-151
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• 1996

After cardiac surgery, it has been recognized that various complications were associated with injured humoral and cellular immunity by cardiopulmonary bypass(CPB). Especially, in postoperative pulmonary dysfunction, transpulmonary leukostasis followed complement activation and inflammatory responses are major pathogen. Some studies have showed that pretreated-corticosteroids before CPB protected postoperative pulmonary dysfunction. Corticosteroids may inhibit complement and leukocyte activation. On based previous studies, present investigator determined changes of leukocyte counts and transpulmonary leukostasis during cardiac surgery and postoperative periods. For the evaluation of postoperative pulmonary function and edema, $PaO_2$ and chest X-ray were compared between pre-CPB and post-CPB. Fever and other parameters were also observed postoperatively. The aim of this study was to define for the prophylactic effects of corticosteroid(Solu-Medrol: 30mg/kg) on all the researched parameters. This study was prospectively designed with randomized-blind fashion for 50 patients undergoing cardiac surgery. According to the purpose of study, all patients were divided into placebo and steroid group. : Placebo group was 25 patients received normal saline(not corticosteroid), and steroid group was 25patients received corticosteroid(Solu-Medrol: 30mg/kg) before initiation of CPB. The results of study were summarized as follows. 1. Total peripheral leukocyte counts decreased significantly at 5 minutes of CPB in all patients(P<0.01), and began to increase progressively at later periods of CPB with neutrophilia. The significant rise remained at postoperative 7th day(P<0.05). 2. During partial CPB, transpulmonary leukostasis occurred in placebo group(P<0.001), whereas it was prevented in steroid group. 3. In both groups, peripheral lymphocyte counts were stable during CPB, but began to reduce at time of intensive care unit(ICU) and the lymphocytopenia remained until postoperative 3rd day. The lymphocyte counts recovered on postoperative 7th day. 4. In both groups, peripheral counts of monocyte were relatively stable in the early peroid of CPB, and increased gradually in the later periods of CPB. This significant monocytosis remained throughout postoperlative periods(P<0.05). 5. The mean value of postoperative $paO)_2$ was lower than that of pre-CPB in placebo group(P=0.01) but didn't significant in steroid group(P=0.90). In the incidence of pulmonary edema signs and fever, placebo group was higher than steroid group(P=0.001, p=0.01, respectively). However mechanical respiratory supporting and care periods at intensive care unit were not significant difference between two groups(P>.0.05).With the above results, the investigator concluded that leukocyte activation and pulmonary sequestration were caused by cardiac surgery with CPB and demonstrated that high dose corticosteroid will provide prophylactic effect for pulmonary leukostasis and higher neutrophilia. These effects may ameliorate postoperative pulmonary dysfunction and contribute to postoperative less morbidity. However, further study should be performed because postoperative lymphocytopenia continued for 3 days in both groups, which may suspected damage or suppression of cell-mediated immunity with used corticosteroid.

• the MEAT Journal
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• s.34 winter
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• pp.14-25
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• 2007

The objective of this study was to investigate the physicochemical, microbiological and sensory properties of food additive-free grilled pork products manufactured using loin (T1), tender loin (T2) and ham (T3). The samples were heated for 30 min at $60^\circC$, and then 50 min for $150^\circC$. After cooling, vacuum packaged grilled pork samples was stored at $4\pm$$1^\circC$ for 40 days. The pH values of grilled pork samples ranged from 5.92 (T1) to 6.10 (T3) at the initial storage time, and from 6.28 (T1) to 6.60 (T3) after 40 days. The water holding capacities (%) was 85.99~93.24% for T1, 85.26~93.89% for T2 and 89.11~94.67% for T3, all of which were slightly higher than those of other pork products. The shear force values of T2 were significantly higher (p<0.05) than those of the other pork products throughout the storage period. The TBARS and VBN values of T2 were significantly higher (p<0.05) than those of T1 and T3. With regard to microorganisms, all grilled pork samples was in good condition, showing 1.93~3.48 log10 CFU/g via total plate counts, and 1.74~3.48 log10 CFU/g for lactic acid bacteria throughout the storage period. Regarding sensory evaluation, the scores of overall acceptability in all products were above 5.0 points through 40 days of storage.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.5 no.1
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• pp.47-55
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• 1999

Applications of chitosan are related to molecular weight and degree of deacetylation(DOD) of chitosan completely. The molecular weight and DOD were greatly affected by the concentration of solution time and temperature. The degree of demineralization was not significantly different at $50^{\circ}C\;and\;70^{\circ}C$ after 30 minutes. Deproteinization decreased as process time increased. The nitrogen content was reached to 6.92% after 90 minute at $80^{\circ}C$, which is similar to theoretical nitrogen content of chitin. The DOD was 82.84% after 2 hours reaction and increased as the reaction time increased in the process. Viscosity and molecular weight are increased as recycling number of concentrated NaOH solution increased. Chemical, biological and physical properties of chitosan depend on the DOD and molecular size of the molecule. Tensile strength of the films from acetic acid solutions was between $28.9{\sim}33.6$ MPa and was generally higher than that of the films from lactic acid. Elongation of the films from lactic acid was between $97.0{\sim}109.7%$ and was generally higher than that of the films from the acetic acid. Water vapor permeability of the films prepared from lcetic acid solutions was between $1.9{\sim}2.3ng{\cdot}m/m^2{\cdot}s{\cdot}Pa$ and was generally higher than that of the films from the acetic acid.

• Food Science of Animal Resources
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• v.26 no.3
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• pp.269-275
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• 2006

The objective of this study was to investigate the physicochemical, microbiological and sensory properties of food additive-free grilled pork products manufactured using loin (T1), tender loin (T2) and ham (T3). The samples were heated for 30 min at $60^{\circ}C$, and then 50 min for $150^{\circ}C$. After cooling, vacuum packaged grilled pork samples was stored at $4{\pm}1^{\circ}C$ for 40 days. The pH values of grilled pork samples ranged from 5.92 (T1) to 6.10 (T3) at the initial storage time, and from 6.28 (T1) to 6.60 (T3) after 40 days. The water holding capacities(%) was $85.99{\sim}93.24%$ for T1, $95.26{\sim}93.89%$ for T2 and $89.11{\sim}94.67%$ for T3, all of which were slightly higher than those of other pork products. The shear force values of T2 were significantly higher(p<0.05) than those of the other pork products throughout the storage period. The TBARS and VBN values of T2 were significantly higher(p<0.05) than those of T1 and T3. With regard to microorganisms, all grilled pork samples was in good condition, showing $1.93{\sim}3.48\;log_{10}$ CFU/g via total plate counts, and $1.74{\sim}3.48\;log_{10}$ CFU/g far lactic acid bacteria throughout the storage period. Regarding sensory evaluation, the scores of overall acceptability in all products were above 5.0 points through 40 days of storage.