571 research outputs found
locally unwanted land use development
Thesis(Master) --KDI School:Master of Development Policy,2014OutstandingmasterpublishedKyung Bok Lee
Luxury Fashion Consumption: The Interplay of Guilt and Pleasure
We draw on the Affect Balance Theory to (a) explore whether two distinct modes of luxury consumption (i.e., conspicuous consumption and style consumption) are related to pleasure (i.e., positive affect) and guilt (i.e., negative affect); and (b) determine whether pleasure and guilt interplay to make interactive impacts, as well as independent impacts, on consumers’ repurchase intention
One-pot Enzymatic Synthesis of Deoxy-thymidine-diphosphate (TDP)-2-deoxy-∝-d-glucose Using Phosphomannomutase
Production of deoxy-thymidine-diphosphate (TDP)-sugars as substrates of glycosyltransferases, has been one of main hurdles for combinatorial antibiotic biosynthesis, which combines sugar moiety with aglycon of various antibiotics. Here, we report the one-pot enzymatic synthesis of TDP-2-deoxy-glucose employing high efficient TMP kinase (TMK; E.C. 2.7.2.12), acetate kinase (ACK; E.C. 2.7.1.21), and TDP-glucose synthase (TGS; E.C. 2.7.7.24) with phosphomannomutase (PMM; E.C. 5.4.2.8). In this study, replacing phosphoglucomutase (PGM; E.C. 5.4.2) by PMM from Escherichia coli gave four times higher specific activity on 2-deoxy-6-phosphate glucose, suggesting that the activity on 2-deoxy-glucose-6-phosphate was mainly affected by PMM activity, not PGM activity. Using an in vitro system starting from TMP and 2-deoxy-glucose-6-phosphate glucose, TDP-2-deoxy-glucose (63% yield) was successfully synthesized. Considering low productivity of NDP-sugars from cheap starting materials, this paper showed how production of NDP-sugars could be enhanced by controlling mutase activity
Preparative Synthesis of dTDP-L-Rhamnose Through Combined Enzymatic Pathways
dTDP-L-rhamnose, an important precursor of O-antigen, was prepared on a large scale from dTMP by executing an one-pot reaction in which six enzymes are involved. Two enzymes, dTDP-4-keto-6-deoxy-D-glucose 3,5-epimerase and dTDP-4-keto-rhamnose reductase, responsible for the conversion of dTDP-4-keto-6-deoxy- D-glucose to dTDP-L-rhamnose, were isolated from their putative sequences in the genome of Mesorhizobium loti, functionally expressed in Escherichia coli, and their enzymatic activities were identified. The two enzymes were combined with an enzymatic process for dTDP-4- keto-6-deoxy-D-glucose involving TMP kinase, acetate kinase, dTDP-glucose synthase, and dTDP-glucose 4,6- dehydratase, which allowed us to achieve a preparative scale synthesis of dTDP-L-rhamnose using dTMP and glucose-1-phosphate as starting materials. About 82% yield of dTDP-L-rhamnose was obtained based on initial dTMP concentration at 20 mM dTMP, 1 mM ATP, 10 mM NADH, 60 mM acetyl phosphate, and 80 mM glucose-1- phosphate. From the reaction with 20 ml volume, approximately 180 mg of dTDP-L-rhamnose was obtained in an overall yield of 60% after two-step purification, that is, anion exchange chromatography and gel filtration for desalting. The purified product was identifiedbyHPLC, ESI-MS,andNMR,showingabout95%purity
Association between work-related health problems and job insecurity in permanent and temporary employees
OBJECTIVES: This research was conducted with an aim of determining the correlation between job insecurity and an employee’s work-related health problems among permanent and temporary workers. METHODS: Using the data from the First Korean Working Conditions Survey conducted in 2006, a total of 7,071 workers, excluding employers and the self-employed, were analyzed. Work-related health problems were categorized as backache, headache, abdominal pain, muscular pain, stress, fatigue, insomnia, anxiety or depression. Each problem was then analyzed for its relationship to job insecurity through logistic regression analysis. RESULTS: Among the 7,071 workers, 5,294 (74.9%) were permanent workers and 1,777 (25.1%) were temporary workers. For the permanent workers, presence of high or moderate job insecurity appeared more closely linked to backache, headache, abdominal pain, muscular pain, stress, fatigue, insomnia, anxiety, and depression compared to absence of job insecurity. However, for the temporary workers, only depression appeared to be associated with the presence of high job insecurity. CONCLUSION: The study showed that the presence of job insecurity is correlated with work-related health problems. The deleterious effects of job insecurity appeared to be stronger in permanent than temporary workers. Additional research should investigate ways to effectively reduce job insecurity
The Poor Outcome of the Delayed Diagnosis of Acute Spontaneous Spinal Epidural Hematoma : Two Cases Report
We present two patients who had acute paraplegia with sensory loss due to spontaneous spinal epidural hematoma (SSEH). One had myocardial infraction and the other had deep vein thrombosis, and the former was treated with anticoagulants and the latter was treated with thrombolytic agent. We analyzed the neurological status of our two cases each between its preoperative and postoperative state. Postoperatively both showed no improvement of neurologic symptom, and on follow-up of 12 months, one showed no neurologic improvement and the other showed a insignificant improvement of lower extremity muscle power (trace knee extensor/ankle dorsiflexor). We thought that this poor outcome was due to delayed operation, which was done more than 24 hr after the symptom onset. The outcome in SSEH is essentially determined by the time taken from symptom onset to operation. Therefore, early and precise diagnosis such as careful history taking and MRI evaluation is necessary
Cloning, expression, purification, crystallization and X-ray crystallographic analysis of glucuronic acid dehydrogenase from Chromohalobacter salexigens. Addendum
An addendum to the article by Ahn et al. [Acta Cryst. (2011) F67, 689–691]
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