• Biomolecules & Therapeutics
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• v.1 no.2
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• pp.196-203
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• 1993

We compared in vitro antibacterial activity of DWC-751, a new parenteral cephalosporin antibiotic, with those of cefpirome (CPR), cefotaxime (CTX) and ceftazidime (CAZ). DWC-751 showed a broad antimicrobial spectrum against Gram-positive and negative bacteria. The antibacterial activity of DWC-751 against Stapylococcus aureus was equal to that of CPR and superior to those of CTX and CAZ. The activity of it against Excherichia coli was more potent than those of CPR, CTX and CAZ. Against Pseudomonas aeruginosa, DWC-751 was slightly inferior to that of CAZ and superior to those of CPR and CTX. The antibacterial activity of DWC-751 was superior to those of CPR, CTX and CAZ against clinical isolates and ofloxacin resistant strains. DWC-751 showed bactericidal action against Escherichia coli at concentrations close to the MIC and induced the formation of filament and burge and lysis of Escherichia coli in a microscopic examination.

• Toxicological Research
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• v.11 no.1
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• pp.109-116
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• 1995

Single intravenous and oral administration to SD rats and ICR mice of both sexes were performed to investigate the acute toxicity of DWC-751, a new parenteral cephalosporin. $LD_50$ values for ICR mice and SD rats administered intravenously with DWC-751 were as follows; 1151.1 mg/kg (male SD rat), 1183.5 mg/kg (female SD rat), 2698.1 mg/kg (male ICR mouse), 2833.0 mg/kg (female ICR mouse). It is suggested that $LD_50$ values in rats and mice of both sexes would be 5000 mg/kg in oral route. Major general symptoms induced by injection intravenously with DWC-751 are decreased motor activity, increased respiratory rate, tremor and convulsion. In oral route, piloerection and soft stool are observed to 4 day after administration. No significant body weight changes were observed at any level in the groups administered with DWC-751. The gross finding of rats administered intravenously was observed cecum distension.

• Biomolecules & Therapeutics
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• v.1 no.1
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• pp.103-108
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• 1993

The synthesis and physicochemical properties of a novel cephalosporin, DWC-751 are described. DWC -751, (6R , 7R)-7-[ (Z)-2-(2-aminothiazol-4-yl)-2- methoxyiminoacetamido]-3-[(1-methylbenzotriazol-3-ium) methyl]-ceph-3-em-4-carboxylate monosulfate($IV_{\alpha}$) was conveniently obtained by the conversion of compound (IV) into the crystalline monosulfate. Adjusting pH 4.8-5.2 in aqeous solution of the crude crystalline, compound(IV) in the form of a crystalline pentahydrate was prepared with a high degree of purity. The influence of the various organic and inorganic acids on the solubility of compoud(IV) and its salts, was examined. Particularly, the solubility of DWC-751 was 92 mg/mι at pH 1.7 and 233 mg/mι at pH 3.0. DWC-751 showed a broad antimicrobial spectrum against gram-positive and negative bacteria.

• Biomolecules & Therapeutics
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• v.1 no.2
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• pp.204-210
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• 1993

The distribution and excretion of DWC-751, a new cephalosporin, were examined in rats and mice following a single intravenous administration. DWC-751 in plasma and urine was determined by both HPLC and microbiological assay. The plasma concentration of the drug declined biexponentially. The initial and terminal half lives of the drug were 3.0 and 28.3 min, respectively. Binding of the drug to plasma proteins was 42.3%. The distribution volume at steacly-state ($Vd_{ss}$) was only 0.341 ι/kg, which is well correlated with the low n-octanol/water partition coefficient of the drug ($K_{o/w{\cong}0$) Actually, the drug was distributed to liver, kidney and lung with very low organ/plasma concentration ratio. The drug, was excreted mainly via renal excretion, i.e., the total($CL_T$) and apparent renal($CL_{R}$) clearances of the drug were 10.8 and 7.5 ml/min/kg, respectively.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.106-106
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• 1993

DWC-751은 그람양성 및 음성균주에 대하여 광범위한 항균스펙트럼을 가지는 것으로 나타났다. 그람양성균 S. aureus에 대하여는 cefpirome과 동등하며, cefotaxime 보다 4배, ceftazidime보다 16배 우수하였고 그람음성균에 대하여 DWC-751의 항균력은 cefpirome, cefotaxime보다 2배, ceftazidime보다 4-8배 우수하였다. Ps. aeruginosa에 대한 DWC-751의 항균력은 ceftazidime과 거의 동등한 항균력을 나타내었고, cefpirome보다 2배, cefotaxime보다 4-8배 우수한 항균력을 나타내었다. 임상분리균주 및 ofloxacin 내성균주에 대한 DWC-751의 항균력은 표준균주에 대한 결과와 같이 대조약물보다 우수하였다. 전신감염치료효과에 있어서 Streptococcus pyogenes, Serratia marcescens, Acinetobacter calcoaceticus, Morganella morganii, Proteus mirabilis에 대한 동물실험 결과, ED$_{50}$치에 의한 효능은 cefotaxime 보다 우수하였으며,Enterobacter cloacae, Pseudomonas aeruginosa에 대하여는 ceftazidime과 거의 동등하였다.

• Journal of Korean Neurosurgical Society
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• v.56 no.1
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• pp.61-65
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• 2014

Neurocutaneous melanosis (NCM) is a rare congenital syndrome consisting of benign or malignant melanotic tumors of the central nervous system with large or numerous cutaneous melanocytic nevi. The Dandy-Walker complex (DWC) is characterized by an enlarged posterior fossa with high insertion of the tentorium, hypoplasia or aplasia of the cerebellar vermis, and cystic dilatation of the fourth ventricle. These each two conditions are rare, but NCM associated with DWC is even more rare. Most patients of NCM with DWC present neurological symptoms early in life such as intracranial hemorrhage, hydrocephalus, and malignant transformation of the melanocytes. We report a 14-year-old male patient who was finally diagnosed as NCM in association with DWC with extensive intracerebral and spinal cord involvement.

• Korean Chemical Engineering Research
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• v.51 no.2
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• pp.245-249
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• 2013

The depropanizing, debutanizing and deisobutanizing fractionation steps of processing natural gas liquids were improved through studying complex distillation arrangements, including the double dividing wall column arrangement (DDWC), the sequence including a dividing wall column (DWC) and a bottom DWC (BDWC), and the sequence including a DWC and a BDWC with top vapor recompression heat pump. These arrangements offer benefits by decreasing reboiler and condenser power consumption. Reducing the number of columns and their diameters can potentially reduce construction costs. The result also showed that operating cost could be reduced most significantly through novel combinations of internal and external heat integration: bottom dividing wall columns employing a top vapor recompression heat pump.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.7
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• pp.45-50
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• 2010

In this paper, we analysis the performance of cooperative spectrum sensing with distance based weight for cognitive radio (CR) systems and CR systems sense the spectrum of the licensed user by using a energy detection method. Threshold is determined in accordance with the constant false alarm rate (CFAR) algorithm for energy detection. The signal of licensed user is OFDM signal and the wireless channel between a licensed user and CR systems is modeled as Gaussian channel. From the simulation results, the cooperative spectrum sensing with distance based weight combining (DWC) and equal gain combing (EGC) methods shows higher spectrum sensing performance than single spectrum sensing does. And the detection probability performance with the DWC is higher than that with the EGC.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.4
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• pp.423-429
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• 2011

Cooperative spectrum sensing is proposed to overcome some problem such as multipath fading and shadowing and to improve spectrum sensing performance. There are different combining methods for cooperative spectrum sensing: hard decision method and soft decision method. In this paper, we analysis the performance of cooperative spectrum sensing with distance based weight that is kind of a soft decision rule for cognitive radio(CR) systems and CR systems sense the spectrum of the licensed user by using a energy detection method. Threshold is determined in accordance with the constant false alarm rate(CFAR) algorithm for energy detection. The signal of licensed user is OFDM signal and the wireless channel between a licensed user and CR systems is modeled as Gaussian channel. From the simulation results, the cooperative spectrum sensing with distance based weight combining(DWC) and equal gain combing(EGC) methods shows higher spectrum sensing performance than single spectrum sensing does. And the detection probability performance with the DWC is higher than that with the EGC.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.3
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• pp.231-236
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• 2022

The research was aimed to improve pre-harvest methods to maintain marketability in postharvest leaf lettuce. In this study, the effect of hydroponics on the growth and post-harvest storage characteristics of 'Chongchima' lettuce grown in peat mass medium hydroponic system using a non-powered culture device or deep water culture (DWC) was evaluated. There was no difference in fresh weight, leaf number, SPAD, moisture content, and C/N ratio between peat moss growing medium hydroponic and DWC methods except plant height. It was found that lettuce cultivation by a nonpowered hydroponics method is easier than the existing DWC. The quality parameters, such as fresh weight loss, SPAD value, and general appearance of lettuce were investigated after harvest. There was no significant difference in fresh weight loss and general appearance during storage of lettuce by the hydroponics methods. However, with the increased storage time of SPAD, which is related to chlorophyll content, was slightly higher in peat moss medium hydroponic was than DWC. When crops such as lettuce are grown under favorable conditions without any agronomic abnormalities, it is suggested that post-harvest storage is not significantly affected by peat moss growing medium hydroponic and DWC.