• Applied Biological Chemistry
• /
• v.26 no.2
• /
• pp.125-131
• /
• 1983

Formal net charges, bond populations, atomic orbital coefficients, energy components and conformation of dimethyl-2,2-dichlorovinylphosphate have been studied theoretically by using the CNDO/2 molecular orbital calculation method in attempt to describe the reactivity and the stability of the molecule. From the analysis of rate equation, molecular orbital calculations and identification of the hydrolysis products, 2,2-dichloroacetaldehyde and dimethylphosphoric acid, a mechanism of the hydrolysis of dimethyl-2,2-dichlorovinylphosphate(DDVP) has been proposed. The hydrolysis of DDVP proceeds through the mechanism of nucleophilic addition, typical Micheal reaction in basic media. Therefore, it appears probable that the attack by strong nucleophile, hydroxide ion occurs at the increased positive charge $C_2({\alpha})$ atom of a staggered conformation due to the inductive effect (-)I>(+)R of 2,2-dichlorovinyl, electron-attracting group. And then, the hydrolytic scission involves the $C_2({\alpha})-O_3$, ${\pi}-anti-bonding\;orbital({\pi}^*)$ in the subsequent reaction in aqueous solution.

• The KIPS Transactions:PartB
• /
• v.9B no.5
• /
• pp.571-578
• /
• 2002

In this paper, we propose a video sequence coding scheme called AMV (Auxiliary Motion Vector) to minimize error propagation caused by transmission errors over the Internet. Unlike the conventional coding schemes the AMY coder, for a macroblock in a frame, selects two best matching blocks among several preceding frames. The best matching block, called a primary block, is used for motion compensation of the destination macroblock. The other block, called an auxiliary block, replaces the primary block in case of its loss at the decoder. When a primary block is corrupted or lost during transmission, the decoder can efficiently and simply suppress error propagation to the subsequent frames by replacing the block with an auxiliary block. This scheme has an advantage of reducing both the number and the impact of error propagations. We implemented the proposed coder by modifying H.263 standard coding and evaluated the performance of our proposed scheme in the simulation. The simulation results show that AMV coder is more efficient than the H.263 baseline coder at the high packet loss rate.

• Archives of Plastic Surgery
• /
• v.36 no.5
• /
• pp.559-564
• /
• 2009

Purpose: Surgical reconstruction of an ischial soft tissue defect presents a challenging problem owing to a high rate of recurrence, especially paraplegic patients. Although various muscle, musculocutaneous and fasciocuta - neous flaps have been used in the reconstruction of ischial soft tissue defect, it is still debated which type of flaps are the best. We had performed a relatively durable adductor magnus perforator island flap based on the perforators originated from the first medial branch of the profunda femoris artery for coverage of ischial soft tissue defect where was not a region universally reconstructed by perforator flap. Methods: From August 2005 until January 2008, the adductor magnus perforator island flap had been used for resurfacing of the ischial soft tissue defects in a series of 6 patients (4 male and 2 female). Ages ranged from 26 to 67 years (mean, 47.5 years), and follow - up period from 13 to 26 months (mean, 16.7 months). Causes were 4 pressure ulcers, 1 cellulitis and 1 suppurative keratinous cyst. Results: The sizes of these flaps ranged from 12 to 18 cm in length and 7 to 9 cm in width. The flaps survived in all patients. Marginal loss over the distal area of the flap by infection was noted in one patient, which was treated successfully with a subsequent split - thickness skin graft. Average thickness of the flap was 0.94 cm, which was more thicker than other perforator flaps. Long term follow - up showed a good flap durability. Conclusion: In planning a reconstructive option of ischial soft tissue defect, the adductor magnus perforator island flap is a relatively large cutaneous flap with a durable thickness. With proper patient selection, careful vascular dissection and postoperative management, we recommend this flap is a good and suitable option for coverage of the ischial soft tissue defect.

• Gut and Liver
• /
• v.12 no.6
• /
• pp.722-727
• /
• 2018

Background/Aims: Although endoscopic bilateral stent-instent placement is challenging, many recent studies have reported promising outcomes regarding technical success and endoscopic re-intervention. This study aimed to evaluate the technical accessibility of stent-in-stent placement using large cell-type stents in patients with inoperable malignant hilar biliary obstruction. Methods: Forty-three patients with inoperable malignant hilar biliary obstruction from four academic centers were prospectively enrolled from March 2013 to June 2015. Results: Bilateral stent-in-stent placement using two large cell-type stents was successfully performed in 88.4% of the patients (38/43). In four of the five cases with technical failure, the delivery sheath of the second stent became caught in the hook-cross-type vertex of the large cell of the first stent, and subsequent attempts to pass a guidewire and stent assembly through the mesh failed. Functional success was achieved in all cases of technical success. Stent occlusion occurred in 63.2% of the patients (24/38), with a median patient survival of 300 days. The median stent patency was 198 days. The stent patency rate was 82.9%, 63.1%, and 32.1% at 3, 6, and 12 months postoperatively, respectively. Endoscopic re-intervention was performed in 14 patients, whereas 10 underwent percutaneous drainage. Conclusions: Large cell-type stents for endoscopic bilateral stent-in-stent placement had acceptable functional success and stent patency when technically successful. However, the technical difficulty associated with the entanglement of the second stent delivery sheath in the hook-cross-type vertex of the first stent may preclude large cell-type stents from being considered as a dedicated standard tool for stent-in-stent placement.

• Cross-Cultural Studies
• /
• v.20
• /
• pp.5-27
• /
• 2010

This paper studies the relation between canonical/variegated babble (CB/VB) and early speech in an infant acquiring Mandarin Chinese from 9 to 17 months. The infant was audio-and video-taped in her home almost every week. The data analyzed here come from 1,621 utterances extracted from 23 sessions ranging from 30 minutes to one hour, from age 00:09;07 to 01:05;27. The data was digitized, and segments from 23 sessions were transcribed in narrow IPA and coded for analysis. Babble was coded from age 00:09;07 to 01:00;00, and words were coded from 01:00;00 to 01:05;27, proto-words appeared at 11 months, and some babble was still present after 01:10;00. 3821 segments were counted in CB/VB utterances, plus the segments found in 899 word tokens. The data transcription was completed and checked by the author and was rechecked by two other researchers who majored in Chinese phonetics in order to ensure the reliability, we reached an agreement of 95.65%. Mandarin Chinese is phonetically very rich in consonants, especially affricates: it has aspirated and unaspirated stops in labial, alveolar, and velar places of articulation; affricates and fricatives in alveolar, retroflex, and palatal places; /f/; labial, alveolar, and velar nasals; a lateral;[h]; and labiovelar and palatal glides. In the child's pre-speech phonetic repertoire, 7 different consonants and 10 vowels were transcribed at 00:09;07. By 00:10;16, the number of phones was more than doubled (17 consonants, 25 vowels), but the rate of increase slowed after 11 months of age. The phones from babbling remained active throughout the child's early and subsequent speech. The rank order of the occurrence of the major class types for both CB and early speech was: stops, approximants, nasals, affricates, fricatives and lateral. As expected, unaspirated stops outnumbered aspirated stops, and front stops and nasals were more frequent than back sounds in both types of utterances. The fact that affricates outnumbered fricatives in the child's late babble indicates the pre-speech influence of the ambient language. The analysis of the data also showed that: 1) the phonetic characteristics of CB/VB and early meaningful speech are extremely similar. The similarities of CB/VB and speech prove that the two are deeply related; 2) The infant has demonstrated similar preferences for certain types of sounds in the two stages; 3) The infant's babbling was patterned at segmental level, and this regularity was similarly evident in the early speech of children. The three types being coronal plus front vowel; labial plus central and dorsal plus back vowel exhibited much overlap in the phonetic forms of CB/ VB and early speech. So the child's CB/ VB at this stage already shared the basic architecture, composition and representation of early speech. The evidence of similarity between CB/VB and early speech leaves no doubt that phones present in CB/VB are indeed precursors to early speech.

• Clinical and Experimental Reproductive Medicine
• /
• v.32 no.3
• /
• pp.217-222
• /
• 2005

Objectives: We aimed to investigate the clinical effect of low-dose intravenous immunoglobulin treatment in unexplained recurrent spontaneous aborters (RSA) with elevated peripheral CD56+ natural killer (NK) cell levels and to determine the pre-conceptional NK cell percentage predictive of subsequent successful pregnancy outcome. Materials and Methods: Sixty four cases of unexplained recurrent miscarriage with elevated peripheral NK cells (>15%) were received low dose IVIg infusion at the dosage of 400 mg/Kg/month after confirmation of gestational sac and continued until 20 weeks. The patients were divided into two groups according to the pregnancy outcome: Group I was success of treatment defined as live birth at or after 25 gestational weeks and Group II was failure of treatment. The preconceptional levels of the peripheral blood NK cells were compared between two groups. Results: Fifty-three pregnancies resulted in live births after 25 weeks and 11 resulted in abortion (Overall success rate of IVIG treatment was 82.8%). Preconceptional CD56+ NK cell percentage in group II ($27.4{\pm}1.9%$) was higher than those in group I ($22.3{\pm}0.8%$). By using ROC curve, optimal discrimination between success and failure of treatment was achieved with ${\leq}27%$ of preconceptional NK cell percentage. Conclusion: In RSA patients with elevated NK cells, we suggest that preconceptional peripheral blood CD56+ NK cell level could be a useful marker for predicting successful treatment outcome of low-dose IVIg infusion.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.4 no.4
• /
• pp.18-25
• /
• 2000

A two-color particle image velocimetry (PIV) has been developed for measuring two dimensional velocity flowfields and applied to a Mach 2.0 supersonic nozzle. This technique is similar to a single-color PIV technique except that two different color laser beams are used to solve the directional ambiguity problem. A green-color laser sheet (532 nm: 2nd harmonic beam of YAG laser) and a red-color laser sheet (619 nm: output beam from YAG pumped Dye laser using Rhodamine 640) are employed to illuminate the seeded particles. A high resolution (3060${\times}$2036) digital color CCD camera is used to record the particle positions. This system eliminates the photographic-film processing time and subsequent digitization time as well as the complexities associated with conventional image shifting techniques for solving directional ambiguity problem. The two-color PIV also has the advantage that velocity distributions in high speed flowfields can be measured simply and accurately by varying the time interval between two different laser beams due to its high signal-to-noise ratio and thereby less requirement of panicle pair numbers for a velocity vector in one interrogation spot. The velocity distribution in the Mach 2.0 supersonic nozzle has been measured and the over-expanded shock cell structure can be predicted by the strain rate field. These results are compared and analyzed with the schlieren photograph for the velocity distributions and shock location.

• Food Science and Preservation
• /
• v.16 no.4
• /
• pp.499-505
• /
• 2009

Quality changes in fresh-cut potatoes during storage at $4^{\circ}C$ after treatment with low-temperature blanching and antibrowning agents were studied. Fresh-cut potatoes were treated by dipping for 1.5 min in a browning inhibitor solution containing 0.5% (w/v) ascorbic acid, 0.5% (w/v) citric acid, 0.5% (w/v) sodium chloride, 0.1% (w/v) trehalose, and 0.005% (w/v) biotin, at $60^{\circ}C$, with subsequent cooling for 1.5 min and storage at $4^{\circ}C$. The browning properties of fresh-cut potatoes were examined by measurement of polyphenol oxidase (PPO) activity and total phenolic content. Changes in quality attributes over a 14-day period were assessed in terms of titratable acidity, pH, water-soluble solid level, and gas analysis at $4^{\circ}C$. During storage, PPO activity increased, with the lowest activity seen after about 7 days of storage. Treatment with antibrowning solution at $4^{\circ}C$ increased visual sensory attributes during storage. Low-temperature blanching in distilled water more effectively inhibited browning compared with exposure to browning inhibitor solution, as assessed after 7 days of storage. Fresh-cut potatoes respired aerobically after different treatments during storage at $4^{\circ}C$.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.41 no.3
• /
• pp.147-154
• /
• 2021

Cutting management has been identified as a critical factor in the alfalfa production systems because it has a significant impact on maximizing yield and maintaining the forage quality. The objective of this experiment was to determine the proper cutting height according to harvesting time for optimizing nutrient yield and forage nutritive quality of alfalfa grown in alpine regions of Korea. Alfalfa was sown at a seeding rate of 30 kg/ha in August 2018 and harvested at four cuttings in 2019 (3 May, 2 July, 11 September, and 13 October). Cutting heights were adjusted at 5, 15, and 25 cm above the soil surface. Alfalfa plant was tallest at the third cutting (109 cm), which was on average 35 cm taller than the first or second cutting. Relative feed value (RFV) remained unaffected by cutting height at the first harvest, but increased consistently in subsequent harvests as cutting height increased. Alfalfa collected at the first and fourth cuttings had the highest RFV (mean 152), which was on average 8 and 67 units higher than the second and third harvests, respectively. At each harvest, in vitro dry matter digestibility was highest in alfalfa cut at a 25-cm height. Dry matter (DM) production at each cutting height was highest in the first cutting, accounting for on average 36-37% of total annual DM production, and lowest in the fourth harvest, accounting for about 11-13% of the total DM yield. The total dry matter production (in four harvests) was 4,218 kg/ha higher when alfalfa was subjected to a cutting height of 5 cm rather than 25 cm. Cutting height had no effect on total crude protein yield, but from the first to fourth cutting, the protein yield followed a decreasing trend. Finally, there were visible declines in forage nutritive quality when alfalfa was cut at a shorter height. However, the magnitude of difference in total forage yield may outweigh the slight decline in forage quality when alfalfa is cut at a lower height. The findings of this study could help the alfalfa growers make better harvest management decisions.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.3
• /
• pp.417-422
• /
• 2019

Hemodynamically unstable pelvic fractures show a remarkably high mortality rate of 40% to 60%. However, their standard of care remains controversial. We report here a case of a 78-year-old woman who was admitted to the Emergency Department with pelvic pain following a fall. Based on pelvic radiography, she was diagnosed with an unstable pelvic fracture. Her blood pressure was 60/40 mmHg, and owing to her unstable vital signs, emergency angiography was performed without computed tomography (CT). Both internal iliac arteries were embolized without sub-branch selection for prompt control of pelvic bleeding. Following embolization, her vital signs were stabilized. Subsequent CT revealed free intra-abdominal air, suggesting bowel perforation had occurred and necessitating emergency laparotomy. An approximately 1 cm-sized free perforation of the small intestine was identified intraoperatively, and primary closure was performed. A retroperitoneal hematoma identified intraoperatively was not explored further because it was a non-expanding and non-pulsatile mass. The patient was admitted to the Intensive Care Unit and transferred to the general ward on postoperative day 3. In this case, the hemodynamically stable pelvic fracture with bowel perforation was successfully and safely treated by prompt angioembolization without conducting CT.