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1.
Article in English | MEDLINE | ID: mdl-37569047

ABSTRACT

Chronic obstructive pulmonary disease (COPD) is a progressive respiratory condition characterized by persistent inflammation in the airways, resulting in narrowing and obstruction of the air passages. The development of COPD is primarily attributed to long-term exposure to irritants, such as cigarette smoke and environmental pollutants. Among individuals hospitalized for exacerbations of COPD, approximately one in five is readmitted within 30 days of discharge or encounters immediate post-discharge complications, highlighting a lack of adequate preparedness for self-management. To address this inadequate preparedness, transitional care services (TCS) have emerged as a promising approach. Therefore, this study primarily aims to present a detailed protocol for a multi-site, single-blind, randomized, controlled trial (RCT) aimed at enhancing self-management competency and overall quality of life for patients with COPD through the provision of TCS, facilitated by a proficient Clinical Research Coordinator. The RCT intervention commenced in September 2022 and is set to conclude in December 2024, with a total of 362 COPD patients anticipated to be enrolled in the study. The intervention program encompasses various components, including an initial assessment during hospitalization, comprehensive self-management education, facilitation of social welfare connections, post-discharge home visits, and regular telephone monitoring. Furthermore, follow-up evaluations are conducted at both one month and three months after discharge to assess the effectiveness of the intervention in terms of preventing re-hospitalization, reducing acute exacerbations, and enhancing disease awareness among participants. The results of this study are expected to provide a basis for the development of TCS fee payment policies for future health insurance.


Subject(s)
Pulmonary Disease, Chronic Obstructive , Transitional Care , Humans , Aged , Pulmonary Disease, Chronic Obstructive/therapy , Hospitalization , Behavior Therapy , Hospitals , Quality of Life , Randomized Controlled Trials as Topic
2.
Combust Flame ; 160(11)2013 Nov 01.
Article in English | MEDLINE | ID: mdl-24273333

ABSTRACT

The pyrolytic and oxidative behaviour of the biofuel 2,5-dimethylfuran (25DMF) has been studied in a range of experimental facilities in order to investigate the relatively unexplored combustion chemistry of the title species and to provide combustor relevant experimental data. The pyrolysis of 25DMF has been re-investigated in a shock tube using the single-pulse method for mixtures of 3% 25DMF in argon, at temperatures from 1200-1350 K, pressures from 2-2.5 atm and residence times of approximately 2 ms. Ignition delay times for mixtures of 0.75% 25DMF in argon have been measured at atmospheric pressure, temperatures of 1350-1800 K at equivalence ratios (ϕ) of 0.5, 1.0 and 2.0 along with auto-ignition measurements for stoichiometric fuel in air mixtures of 25DMF at 20 and 80 bar, from 820-1210 K. This is supplemented with an oxidative speciation study of 25DMF in a jet-stirred reactor (JSR) from 770-1220 K, at 10.0 atm, residence times of 0.7 s and at ϕ = 0.5, 1.0 and 2.0. Laminar burning velocities for 25DMF-air mixtures have been measured using the heat-flux method at unburnt gas temperatures of 298 and 358 K, at atmospheric pressure from ϕ = 0.6-1.6. These laminar burning velocity measurements highlight inconsistencies in the current literature data and provide a validation target for kinetic mechanisms. A detailed chemical kinetic mechanism containing 2768 reactions and 545 species has been simultaneously developed to describe the combustion of 25DMF under the experimental conditions described above. Numerical modelling results based on the mechanism can accurately reproduce the majority of experimental data. At high temperatures, a hydrogen atom transfer reaction is found to be the dominant unimolecular decomposition pathway of 25DMF. The reactions of hydrogen atom with the fuel are also found to be important in predicting pyrolysis and ignition delay time experiments. Numerous proposals are made on the mechanism and kinetics of the previously unexplored intermediate temperature combustion pathways of 25DMF. Hydroxyl radical addition to the furan ring is highlighted as an important fuel consuming reaction, leading to the formation of methyl vinyl ketone and acetyl radical. The chemically activated recombination of HȮ2 or CH3Ȯ2 with the 5-methyl-2-furanylmethyl radical, forming a 5-methyl-2-furylmethanoxy radical and ȮH or CH3Ȯ radical is also found to exhibit significant control over ignition delay times, as well as being important reactions in the prediction of species profiles in a JSR. Kinetics for the abstraction of a hydrogen atom from the alkyl side-chain of the fuel by molecular oxygen and HȮ2 radical are found to be sensitive in the estimation of ignition delay times for fuel-air mixtures from temperatures of 820-1200 K. At intermediate temperatures, the resonantly stabilised 5-methyl-2-furanylmethyl radical is found to predominantly undergo bimolecular reactions, and as a result sub-mechanisms for 5-methyl-2-formylfuran and 5-methyl-2-ethylfuran, and their derivatives, have also been developed with consumption pathways proposed. This study is the first to attempt to simulate the combustion of these species in any detail, although future refinements are likely necessary. The current study illustrates both quantitatively and qualitatively the complex chemical behavior of what is a high potential biofuel. Whilst the current work is the most comprehensive study on the oxidation of 25DMF in the literature to date, the mechanism cannot accurately reproduce laminar burning velocity measurements over a suitable range of unburnt gas temperatures, pressures and equivalence ratios, although discrepancies in the experimental literature data are highlighted. Resolving this issue should remain a focus of future work.

3.
Chest ; 137(2): 393-400, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19741059

ABSTRACT

BACKGROUND: Early detection of drug-resistant Mycobacterium tuberculosis is important for the control and prevention of disease transmission. However, conventional drug susceptibility tests for drug-resistant M tuberculosis take at least 3 to 8 weeks. Here, we report the clinical efficacy of direct DNA sequencing analysis for detecting drug-resistant TB on sputum specimens in a clinical setting. METHODS: A total of 113 sputum specimens from 111 patients, who were suspected of having drug-resistant TB by clinicians, were used for DNA sequencing of katG, rpoB, embB, and pncA genes for isoniazid (INH), rifampin (RIF), ethambutol (EMB), and pyrazinamide (PZA) resistance, respectively, and the results were compared with drug susceptibility tests. The optimization of antituberculosis drugs according to the results of DNA sequencing and the treatment outcomes of the patients were also analyzed. RESULTS: Turnaround time of the direct DNA sequencing analysis was 3.8 +/- 1.8 days. We found mutations related to drug resistance in 30 clinical specimens for katG, 39 for rpoB, 13 for embB, and 24 for pncA. The sensitivity and specificity of the assay were 63.6% and 94.6% for INH, 96.2 and 93.9% for RIF, 69.2% and 97.5% for EMB, and 100% and 92.6% for PZA, respectively. Of the patients with RIF resistance, including multidrug-resistant TB by the assay, 92.5% of the patients with initial first-line antituberculosis drugs were changed to second-line antituberculosis drugs, and treatment was successful in 61.9% of these cases. CONCLUSION: Direct DNA sequencing analysis of clinical sputum specimens is a rapid and useful method for the detection and treatment of drug-resistant TB.


Subject(s)
DNA Mutational Analysis/methods , DNA, Bacterial/analysis , Mutation , Mycobacterium tuberculosis/genetics , Sputum/microbiology , Tuberculosis, Multidrug-Resistant/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Amidohydrolases/genetics , Bacterial Proteins/genetics , Catalase/genetics , DNA-Directed RNA Polymerases , Female , Humans , Male , Middle Aged , Mycobacterium tuberculosis/isolation & purification , Mycobacterium tuberculosis/metabolism , Pentosyltransferases/genetics , Polymerase Chain Reaction , Retrospective Studies , Sensitivity and Specificity , Tuberculosis, Multidrug-Resistant/microbiology , Young Adult
4.
Respiration ; 79(4): 296-301, 2010.
Article in English | MEDLINE | ID: mdl-19602867

ABSTRACT

BACKGROUND: Hemoptysis is a potentially serious clinical problem. However, there is no consensus on the clinical characteristics, treatment and patient outcome of catamenial hemoptysis. OBJECTIVE: Clinical characteristics, treatments and outcome in patients of catamenial hemoptysis were evaluated. METHODS: We conducted a retrospective nationwide observational analysis of Korean patients with catamenial hemoptysis. RESULTS: Nineteen patients with catamenial hemoptysis were evaluated from 13 tertiary-care hospitals in Korea. The median age of the patients was 25 years; 8 (42%) were ever-smokers. Eight patients were pathologically diagnosed; 11 were diagnosed by clinical criteria. Sixteen (84%) patients had a history of obstetric or gynecological procedures before developing hemoptysis. The mean amount of hemoptysis (mean +/- SD) was 58.3 +/- 71.3 for surgery, 46.4 +/- 33.2 for hormonal and 29.1 +/- 26.3 for conservative treatment groups. Hemoptysis did not recur in 8 (89%) of 9 patients after surgery. None of the patients in the hormonal or conservative treatment groups had persistent hemoptysis. There was an excellent outcome (complete remission and partial responses) in all patients with conservative treatment, suggesting that endometrial cells implanted into the lung may have a benign course. CONCLUSION: Patients without massive hemoptysis can be treated conservatively or with hormonal agents.


Subject(s)
Endometriosis/epidemiology , Hemoptysis/epidemiology , Adolescent , Adult , Bronchoscopy , Endometriosis/complications , Endometriosis/diagnostic imaging , Female , Hemoptysis/diagnostic imaging , Hemoptysis/etiology , Humans , Middle Aged , Radiography, Thoracic , Republic of Korea/epidemiology , Retrospective Studies , Tomography, X-Ray Computed , Treatment Outcome , Young Adult
5.
J Phys Chem A ; 110(39): 11291-7, 2006 Oct 05.
Article in English | MEDLINE | ID: mdl-17004738

ABSTRACT

Solvent-induced spectral shifts of the four C40 carotenoids, beta-carotene, echinenone, canthaxantin, and astaxanthin, have been studied in supercritical CO2 and CF3H. In situ absorption spectroscopic analysis was used to determine the maximum peak position of the electronic transitions from the ground state (1(1)Ag-) to the S2 state (1(1)Bu+) of the carotenoids. The medium polarizability function, R(n) = (n2 - 1)/(n2 + 2) of the refractive index of the solvent was varied over the range R(n) = 0.08-0.14, by changing the pressure of CO2 or CF3H between 90 and 300 bar at the temperature 308 K. For all the carotenoids studied here, a significant hypsochromic shift of ca. 20-30 nm was observed in supercritical fluids as compared to that in nonpolar liquids. The spectral shifts in supercritical fluids were compared with those in liquids and showed a clear linear dependence on the medium polarizability. The temperature-dependent shift of the absorption maxima was less significant. Interestingly, there was almost no difference in the energetic position of the absorption maxima in supercritical CO2 and CF3H at a given R(n) value. This is in contrast to previous extrapolations from studies in liquids at larger R(n) values, which yielded different slopes of the R(n)-dependent spectral shifts for polar and nonpolar solvents toward the gas-phase limit of R(n) = 0. The current experimental results in the gas-to-liquid range show that the polarity of the solvent has only a minor influence on the 1(1)Ag- --> 1(1)Bu+ transition energy in the region of low R(n). We also obtain more reliable extrapolations of this 0-0 transition energy to the gas-phase limit nu(0-0)(gas-phase) approximately (23,000 +/- 120) cm(-1) for beta-carotene.


Subject(s)
Canthaxanthin/chemistry , Carotenoids/chemistry , Chemistry, Physical/methods , Chlorofluorocarbons, Methane/chemistry , beta Carotene/chemistry , Carbon Dioxide/chemistry , Models, Chemical , Pressure , Solvents , Spectrophotometry , Temperature , Xanthophylls/chemistry
6.
J Phys Chem A ; 110(8): 2613-21, 2006 Mar 02.
Article in English | MEDLINE | ID: mdl-16494370

ABSTRACT

The rate constants of the recombination reaction of p-fluorobenzyl radicals, p-F-C6H4CH2 + p-F-C6H4CH2 (+M) --> C14H12F2 (+M), have been measured over the pressure range 0.2-800 bar and the temperature range 255-420 K. Helium, argon, and CO2 were employed as bath gases (M). At pressures below 0.9 bar in Ar and CO2, and 40 bar in He, the rate constant k1 showed no dependence on the pressure and the nature of the bath gas, clearly indicating that it had reached the limiting high-pressure value of the energy-transfer (ET) mechanism (k(1,infinity)ET). A value of k(1,infinity)ET(T) = (4.3 +/- 0.5) x 10(-11) (T/300 K)(-0.2) cm3 molecule(-1) s(-1) was determined. At pressures above about 5 bar, the k1 values in Ar and CO2 were found to gradually increase in a pressure range where according to energy-transfer mechanism, they should remain at the constant value k(1,infinity)ET. The enhancement of the recombination rate constant beyond the value k(1,infinity)ET increased in the order He < Ar < CO2, and it became more pronounced with decreasing temperature. The dependences of k1 on pressure, temperature, and the bath gas were similar to previous observations in the recombination of benzyl radicals. The effect of fluorine-substitution of the benzyl ring on k1 values is discussed. The present results confirm the significant role of radical complexes in the recombination kinetics of benzyl-type radicals in the gas-liquid transition range. The observations on a rate enhancement beyond the experimental value of k(1,infinity)ET at elevated densities up to the onset of diffusion-control are consistently explained by the kinetic contribution of a "radical-complex" mechanism which is solely based on standard van der Waals interaction between radicals and bath gases.

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