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1.
Sensors (Basel) ; 22(15)2022 Jul 30.
Article in English | MEDLINE | ID: mdl-35957283

ABSTRACT

Magneto-mechano-electric (MME) composite devices have been used in energy harvesting and magnetic field sensing applications due to their advantages including their high-performance, simple structure, and stable properties. Recently developed MME devices can convert stray magnetic fields into electric signals, thus generating an output power of over 50 mW and detecting ultra-tiny magnetic fields below pT. These inherent outstanding properties of MME devices can enable the development of not only self-powered energy harvesters for internet of thing (IoT) systems but also ultra-sensitive magnetic field sensors for diagnosis of human bio-magnetism or others. This manuscript provides a brief overview of recently reported high-performance MME devices for energy harvesting and magnetic sensing applications.


Subject(s)
Electricity , Magnetic Fields , Endrin/analogs & derivatives , Humans , Physical Phenomena
3.
J Hazard Mater ; 403: 123991, 2021 02 05.
Article in English | MEDLINE | ID: mdl-33265029

ABSTRACT

Microplastics (MPs) and nanoplastics (NPs) seriously contaminate environments by adsorbing environmentally hazardous chemicals. NPs (<1 µm) are not removed by conventional wastewater treatment processes, and have strong sorption capacity for the environmentally hazardous chemicals because of their high surface area. This study revealed that large amounts of MPs are generated in the eye-glass lens polishing process. Qualitative analyses of MPs were performed via Fourier-transform infrared (FTIR) and Raman spectroscopy. Particle size distribution was measured through particle size analysis based on light diffraction. MPs were quantified in the wastewater by measuring the mass balance using membrane filtration with polyaluminum chloride coagulation. One liter of wastewater contained 1380-62,539 mg MPs [corrected] and 0.0136-0.0324 mg NPs. Wastewater from 140,000 eye-glass shops in South Korea is discharged into wastewater plants, and about 57 g NPs per day pass through the wastewater treatment process. The amount of NPs that accumulate daily is likely to increase dramatically. Increased heavy metal concentrations after acid digestion confirmed that MPs in the wastewater adsorbed heavy metals. Detection of various types of volatile organic compounds in the wastewater indicated that workers in eye-glass shops are exposed to the significantly hazardous environments.

4.
J Allergy Clin Immunol Pract ; 9(2): 929-936.e7, 2021 02.
Article in English | MEDLINE | ID: mdl-32961314

ABSTRACT

BACKGROUND: Because severe cutaneous adverse reactions (SCARs), such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug reaction with eosinophilia and systemic symptoms (DRESS) rarely occur, clinical data based on large-scale studies are still lacking. OBJECTIVE: To provide information on culprit drugs and clinical characteristics, including morbidity and mortality of SCARs based on a nationwide registry. METHODS: SCAR cases that occurred from 2010 to 2015 were recruited to the Korean SCAR registry from 34 tertiary referral hospitals. Demographics, causative drugs, causality, and clinical outcomes were collected by reviewing the medical record. RESULTS: A total of 745 SCAR cases (384 SJS/TEN cases and 361 DRESS cases) due to 149 drugs were registered. The main causative drugs were allopurinol (14.0%), carbamazepine (9.5%), vancomycin (4.7%), and antituberculous agents (6.3%). A strong preference for SJS/TEN was observed in carbonic anhydrase inhibitors (100%), nonsteroidal anti-inflammatory drugs (84%), and acetaminophen (83%), whereas dapsone (100%), antituberculous agents (81%), and glycopeptide antibacterials (78%) were more likely to cause DRESS. The mortality rate was 6.6% (SJS/TEN 8.9% and DRESS 4.2%). The median time to death was 19 days and 29 days in SJS/TEN and DRESS respectively, and 89.8% of deaths occurred within 60 days after the onset of the skin symptoms. CONCLUSION: Allopurinol, carbamazepine, vancomycin, and antituberculous agents were the leading causes of SCARs in Korea. Some drugs preferentially caused a specific phenotype. The mortality rate of SCARs was 6.6%, and most of the deaths occurred within 2 months.


Subject(s)
Stevens-Johnson Syndrome , Allopurinol/adverse effects , Carbamazepine , Humans , Registries , Republic of Korea/epidemiology , Stevens-Johnson Syndrome/epidemiology
5.
Medicine (Baltimore) ; 99(10): e19469, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32150106

ABSTRACT

The profiles of sensitization based on component-resolved diagnosis (CRD) differ from region to region in populations sensitized to birch pollen. We investigated the endotypes of birch pollen-sensitized Korean children with allergic diseases using CRD and distinguished the endotypes of oral allergy syndrome (OAS) among them.Thirty-one birch pollen-sensitized children with allergic diseases were enrolled. Specific immunoglobulin E (IgE) to birch pollen and fruit including apple, peach, and kiwi were evaluated via skin prick tests and ImmunoCAP in all subjects. Sensitization profiles based on CRD were evaluated with the Immuno-solid-phase Allergen Chip for birch pollen-sensitization using birch pollen components (Bet v 1, Bet v 2, and Bet v 4), and for OAS using the allergen families pathogenesis-related class 10 proteins (PR-10), lipid transfer proteins, and profilin.All patients (n = 13) with OAS were sensitive to Bet v 1. However, 61% (11/18) of patients without OAS were sensitized to Bet v 1. The level of specific IgE to Bet v 1 was higher in patients with OAS than in those without OAS. All birch pollen-sensitized Korean children with OAS were sensitized to PR-10, and 69% (9/13) of them were mono-sensitized to PR-10. Among patients without OAS, 33% (6/18) were not sensitized to any of the allergen families.Birch pollen-sensitized Korean children with allergic diseases showed unique patterns of sensitization to Bet v 1, Bet v 2, and Bet v 4, and the sensitization profiles based on CRD were totally different according to the presence of OAS.


Subject(s)
Allergens/immunology , Betula/immunology , Food Hypersensitivity/immunology , Pollen/immunology , Adolescent , Child , Child, Preschool , Cross Reactions , Female , Food Hypersensitivity/complications , Fruit/immunology , Humans , Male , Reproducibility of Results , Republic of Korea , Sensitivity and Specificity , Skin Tests
6.
J Nanosci Nanotechnol ; 19(10): 6152-6157, 2019 Oct 01.
Article in English | MEDLINE | ID: mdl-31026927

ABSTRACT

To solve charge-imbalanced problem caused by excessive electron injection into the emitting layer (EML) of quantum dot light emitting diodes (QLEDs) with ZnO electron transport layer (ETL), we proposed QLEDs with TPBi((2,2',2''-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole)))/ZnO ETL layered design. Spin coated TPBi demonstrated lower value of the lowest unoccupied molecular orbital (LUMO) than conduction band maximum (CBM) of ZnO, resulting in effective prevention of excessive injection of electrons into the EML even under excessive stress conditions. Experimental results demonstrated that QLEDs with TPBi/ZnO ETL not only could minimize charge imbalanced problem under high current density operation, but also could increase the maximum luminance of QLEDs by up to 156% (i.e., from 10,320 to 16,081 cd/m²). In addition, the new design with TPBi resulted in low roll-off phenomenon in external quantum efficiency (EQE)-current density characteristics.

7.
Korean J Intern Med ; 33(5): 1008-1015, 2018 09.
Article in English | MEDLINE | ID: mdl-29277095

ABSTRACT

BACKGROUND/AIMS: We evaluated the management and educational status of adult anaphylaxis patients at emergency departments (EDs). METHODS: Anaphylaxis patients who visited ED from 2011 to 2013 were enrolled from three hospitals. We analyzed clinical features, prior history of anaphylaxis, management and provided education for etiology and/or prevention. For analyzing associated factors with epinephrine injection, Pearson chi-square test was used by SPSS version 21 (IBM Co.). RESULTS: A total of 194 anaphylaxis patients were enrolled. Ninety-nine patients (51%) visited ED by themselves. Time interval from symptom onset to ED visit was 62 ± 70.5 minutes. Drug (56.2%) was the most frequent cause of anaphylaxis. Forty-seven patients (24.2%) had prior history of anaphylaxis and 33 patients had same suspicious cause with current anaphylaxis. Cutaneous (88.7%) and respiratory (72.7%) symptoms were frequent. Hypotension was presented in 114 patients (58.8%). Mean observation time in ED was 12 ± 25.7 hours and epinephrine was injected in 114 patients (62%). In 68 patients, epinephrine was injected intramuscularly with mean dose of 0.3 ± 0.10 mg. Associated factor with epinephrine injection was hypotension (p = 0.000). Twenty-three patients (13%) were educated about avoidance of suspicious agent. Epinephrine auto-injectors were prescribed only in five patients. Only 34 (19%) and 72 (40%) patients were consulted to allergist at ED and outpatient allergy department respectively. CONCLUSION: We suggested that management and education of anaphylaxis were not fully carried out in ED. An education and promotion program on anaphylaxis is needed for medical staff.


Subject(s)
Anaphylaxis , Educational Status , Emergency Service, Hospital , Adult , Aged , Anaphylaxis/therapy , Female , Humans , Male , Middle Aged , Republic of Korea , Retrospective Studies
8.
Exp Neurobiol ; 26(4): 227-239, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28912645

ABSTRACT

Glucagon like peptide-1 (GLP-1) stimulates glucose-dependent insulin secretion. Dipeptidyl peptidase-4 (DPP-4) inhibitors, which block inactivation of GLP-1, are currently in clinical use for type 2 diabetes mellitus. Recently, GLP-1 has also been reported to have neuroprotective effects in cases of cerebral ischemia. We therefore investigated the neuroprotective effects of GLP-1 receptor (GLP-1R) agonist, exendin-4 (ex-4), after cerebral ischemia-reperfusion injury. Transient middle cerebral artery occlusion (tMCAO) was induced in rats by intracerebroventricular (i.c.v.) administration of ex-4 or ex9-39. Oxygen-glucose deprivation was also induced in primary neurons, bEnd.3 cells, and BV-2. Ischemia-reperfusion injury reduced expression of GLP-1R. Additionally, higher oxidative stress in SOD2 KO mice decreased expression of GLP-1R. Downregulation of GLP-1R by ischemic injury was 70% restored by GLP-1R agonist, ex-4, which resulted in significant reduction of infarct volume. Levels of intracellular cyclic AMP, a second messenger of GLP-1R, were also increased by 2.7-fold as a result of high GLP-1R expression. Moreover, our results showed that ex-4 attenuated pro-inflammatory cyclooxygenase-2 (COX-2) and prostaglandin E2 after MCAO. C-Jun NH2 terminal kinase (JNK) signaling, which stimulates activation of COX-2, was 36% inhibited by i.c.v. injection of ex-4 at 24 h. Islet-brain 1 (IB1), a scaffold regulator of JNK, was 1.7-fold increased by ex-4. GLP-1R activation by ex-4 resulted in reduction of COX-2 through increasing IB1 expression, resulting in anti-inflammatory neuroprotection during stroke. Our study suggests that the anti-inflammatory action of GLP-1 could be used as a new strategy for the treatment of neuroinflammation after stroke accompanied by hyperglycemia.

9.
Exp Neurobiol ; 26(4): 213-226, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28912644

ABSTRACT

Postconditioning has been shown to protect the mouse brain from ischemic injury. However, the neuroprotective mechanisms of postconditioning remain elusive. We have found that toll-like receptor 5 (TLR5) plays an integral role in postconditioning-induced neuroprotection through Akt/nuclear factor kappa B (NF-κB) activation in cerebral ischemia. Compared to animals that received 30 min of transient middle cerebral artery occlusion (tMCAO) group, animals that also underwent postconditioning showed a significant reduction of up to 60.51% in infarct volume. Postconditioning increased phospho-Akt (p-Akt) levels and NF-κB translocation to the nucleus as early as 1 h after tMCAO and oxygen-glucose deprivation. Furthermore, inhibition of Akt by Akt inhibitor IV decreased NF-κB promoter activity after postconditioning. Immunoprecipitation showed that interactions between TLR5, MyD88, and p-Akt were increased from postconditioning both in vivo and in vitro. Similar to postconditioning, flagellin, an agonist of TLR5, increased NF-κB nuclear translocation and Akt phosphorylation. Our results suggest that postconditioning has neuroprotective effects by activating NF-κB and Akt survival pathways via TLR5 after cerebral ischemia. Additionally, the TLR5 agonist flagellin can simulate the neuroprotective mechanism of postconditioning in cerebral ischemia.

10.
Korean J Intern Med ; 32(5): 910-915, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28352059

ABSTRACT

BACKGROUND/AIMS: The Cough Symptom Score (CSS) is a simple, useful tool for measuring cough severity. However, there is no standard Korean version of the CSS. We developed a Korean version of the CSS and evaluated its clinical utility and validity for assessing chronic cough severity. METHODS: The CSS was adapted for Korean use following a forward-backward translation procedure. Patients with chronic cough enrolled from five university hospitals were graded using the CSS and a 100-mm linear visual analog scale (VAS) of cough severity at each visit. Patients completed the Leicester Cough Questionnaire (LCQ) upon presentation and completed the LCQ and Global Rating of Change at follow-up visits after 2 to 4 weeks. The concurrent validity, repeatability, and responsiveness of the Korean version of the CSS were determined. RESULTS: Correlation coefficients between the CSS and LCQ, and between the CSS and VAS, were -0.66 and 0.52, respectively. There was a weak correlation between the scores for night and day symptoms (r = 0.24, p = 0.0006). The repeatability of the CSS in patients with no change in cough (n = 23) was high (intra-class correlation coefficient, 0.75; 95% confidence interval [CI], 0.51 to 0.88). Patients who reported an improvement in cough (n = 30) at follow-up visits had a significant improvement in the CSS (median, -2; 95% CI, -3 to -1; p = 0.0003). CONCLUSIONS: The Korean version of the CSS correlated well with other tools for accessing cough severity in chronic cough patients. Therefore, it could be a reliable method for measuring chronic cough severity.


Subject(s)
Cough/diagnosis , Surveys and Questionnaires , Adult , Chronic Disease , Cough/physiopathology , Cough/psychology , Female , Hospitals, University , Humans , Male , Middle Aged , Predictive Value of Tests , Quality of Life , Reproducibility of Results , Republic of Korea , Severity of Illness Index , Translating
11.
J Asthma ; 53(7): 761-9, 2016 09.
Article in English | MEDLINE | ID: mdl-27096388

ABSTRACT

OBJECTIVE: We examined the physician perspectives on asthma management in Asia. METHODS: An online/face-to-face, questionnaire-based survey of respiratory specialists and primary care physicians from eight Asian countries/region was carried out. The survey explored asthma control, inhaler selection, technique and use; physician-patient communications and asthma education. Inclusion criteria were >50% of practice time spent on direct patient care; and treated >30 patients with asthma per month, of which >60% were aged >12 years. RESULTS: REALISE Asia (Phase 2) involved 375 physicians with average 15.9(±6.8) years of clinical experience. 89.1% of physicians reporting use of guidelines estimated that 53.2% of their patients have well-controlled (GINA-defined) asthma. Top consideration for inhaler choice was asthma severity (82.4%) and lowest, socio-economic status (32.5%). Then 54.7% of physicians checked their patients' inhaler techniques during consultations but 28.2(±19.1)% of patients were using their inhalers incorrectly; 21.1-57.9% of physicians could spot improper inhaler techniques in video demonstrations. And 79.6% of physicians believed combination inhalers could increase adherence because of convenience (53.7%), efficacy (52.7%) and usability (18.9%). Initial and follow-up consultations took 16.8(±8.4) and 9.2(±5.3) minutes, respectively. Most (85.1%) physicians used verbal conversations and least (24.5%), video demonstrations of inhaler use; 56.8% agreed that patient attitudes influenced their treatment approach. CONCLUSION: Physicians and patients have different views of 'well-controlled' asthma. Although physicians informed patients about asthma and inhaler usage, they overestimated actual usage and patients' knowledge was sub-optimal. Physician-patient interactions can be augmented with understanding of patient attitudes, visual aids and ancillary support to perform physical demonstrations to improve treatment outcomes.


Subject(s)
Anti-Asthmatic Agents/administration & dosage , Asthma/drug therapy , Nebulizers and Vaporizers , Patient Education as Topic/organization & administration , Physician-Patient Relations , Administration, Inhalation , Adolescent , Adult , Anti-Asthmatic Agents/therapeutic use , Asia , Asthma/physiopathology , Audiovisual Aids , Child , Female , Humans , Male , Middle Aged , Primary Health Care , Severity of Illness Index , Socioeconomic Factors , Specialization , Young Adult
12.
J Asthma Allergy ; 8: 93-103, 2015.
Article in English | MEDLINE | ID: mdl-26445555

ABSTRACT

PURPOSE: Asthma is a global health problem, and asthma prevalence in Asia is increasing. The REcognise Asthma and LInk to Symptoms and Experience Asia study assessed patients' perception of asthma control and attitudes toward treatment in an accessible, real-life adult Asian population. PATIENTS AND METHODS: An online survey of 2,467 patients with asthma from eight Asian countries/regions, aged 18-50 years, showed greater than or equal to two prescriptions in previous 2 years and access to social media. Patients were asked about their asthma symptoms, exacerbations and treatment type, views and perceptions of asthma control, attitudes toward asthma management, and sources of asthma information. RESULTS: Patients had a mean age of 34.2 (±7.4) years and were diagnosed with asthma for 12.5 (±9.7) years. Half had the Global Initiative for Asthma-defined uncontrolled asthma. During the previous year, 38% of patients visited the emergency department, 33% were hospitalized, and 73% had greater than or equal to one course of oral corticosteroids. About 90% of patients felt that their asthma was under control, 82% considered their condition as not serious, and 59% were concerned about their condition. In all, 66% of patients viewed asthma control as managing attacks and 24% saw it as an absence of or minimal symptoms. About 14% of patients who correctly identified their controller inhalers had controlled asthma compared to 6% who could not. CONCLUSION: Patients consistently overestimated their level of asthma control contrary to what their symptoms suggest. They perceived control as management of exacerbations, reflective of a crisis-oriented mind-set. Interventions can leverage on patients' trust in health care providers and desire for self-management via a new language to generate a paradigm shift toward symptom control and preventive care.

14.
Allergy Asthma Immunol Res ; 3(1): 46-52, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21217925

ABSTRACT

PURPOSE: The objective of this study was to evaluate skills in handling inhalers and factors associated with these skills among patients with asthma who had undergone treatment at special asthma and allergy clinics in Korea. METHODS: We enrolled 78 subjects who used Turbuhaler and 145 who used Diskus for asthma control at special clinics in 10 university hospitals and visually assessed their skills in handling these inhalers. We also evaluated skills in 137 subjects who had used pressurized metered-dose inhalers (pMDIs) for symptom relief. Age, sex, duration of asthma and inhaler use, smoking status, monthly income, highest grade completed in school and previous instruction for handling inhalers were also measured to evaluate their association with overall inhaler skills. RESULTS: Performance grade was inadequate for 12.8% of participants using Turbuhaler, 6.2% for Diskus, and 23.4% for pMDIs. The success rates for each step in handling the inhalers were relatively high except for the "exhale slowly to residual volume" step, in which success rates ranged from 24.2% to 28.5%. Older age, male sex, lower educational grade, and absence of previous instruction for handling inhalers were associated with inadequate inhaler technique in univariate analysis; however, only older age and absence of previous instruction remained significant independent risk factors in multivariate analysis. CONCLUSIONS: Among Korean asthmatic patients in special asthma and allergy clinics, skills in handling their inhalers were mostly excellent; meanwhile, older age and absence of previous instruction for handling inhalers were associated with inadequate techniques.

16.
J Korean Med Sci ; 25(8): 1134-9, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20676322

ABSTRACT

We evaluated the utility and feasibility of customizing Asthma Control Test (ACT) items to generate a Korean Asthma Control Test (KACT) specific for Korean patients. We surveyed 392 asthma patients with 19 items, selected to reflect the Korean sociocultural context. Guideline ratings were integrated with the evaluations of specialists (i.e., using both guide base rating together with specialist's rating), and items with the greatest discriminating validity were identified. Stepwise regression methods were used to select items. KACT scale scores showed significant differences between the asthma control ratings generated by integrating ratings (r=0.77, P<0.001), by specialist's evaluations (r=0.54, P<0.001), or by FEV(1) percent predicted (r=0.39, P<0.001). Specialist's and guideline ratings detected 56% and 48.6% of patients with well-controlled asthma, respectively. However, the integrated ratings indicated that only 34.3% of the patients in the test sample were well controlled. The overall agreement between KACT and the integrated rating ranged from 45% to 78%, depending on the cut-off points used. It is possible to formulate a valid, useful country-specific diagnostic tool for the assessment of asthma patients based on the original ACT that reflect differences in sociocultural context.


Subject(s)
Asthma/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , ROC Curve , Socioeconomic Factors , Surveys and Questionnaires
17.
J Asthma ; 47(6): 680-6, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20632781

ABSTRACT

BACKGROUND AND OBJECTIVE: Asthma is an example of a chronic disease for which there are evidence-based guidelines for primary care. The authors undertook this study to demonstrate that physicians' use and adherence to asthma management guidelines are improved when the guidelines are furnished in a computer-based format. METHODS: Based on established guidelines, the authors devised a practical and simple computer-assisted program focused on asthma treatment and monitoring. They then undertook a preliminary investigation, "Easy Asthma Management (EAM)" study, using this program. Finally, the authors evaluated the program's effectiveness by measuring clinical outcomes and changes in prescription patterns before and after the study. RESULTS: A total of 4682 asthma patients followed by 377 physicians were recruited, and 2187 completed the study (46.7%). The means of diurnal and nocturnal symptom scores were significantly reduced after a 3-month enrollment in the EAM study. Interestingly, the fraction of prescriptions for oral beta(2)-agonists, oral methylxanthines, and systemic steroids (oral or injection) significantly decreased after the EAM study (p = .02, p <.001, p <.001, respectively), whereas the fraction of prescriptions for inhaled forms of steroids combined with beta(2)-agonists increased significantly (p <.001). CONCLUSIONS: These findings suggest that a computer-assisted asthma management program can be used to improve the clinical outcomes of patients with asthma, and increase physician adherence to established guidelines.


Subject(s)
Anti-Asthmatic Agents/administration & dosage , Asthma/drug therapy , Guideline Adherence , Asthma/immunology , Chi-Square Distribution , Decision Making, Computer-Assisted , Disease Management , Forced Expiratory Volume , Guidelines as Topic , Humans , Physicians
19.
J Asthma ; 46(9): 944-50, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19905924

ABSTRACT

BACKGROUND: While initial education and regular evaluation of inhaler technique in patients are emphasized in the management of asthma and chronic obstructive pulmonary disease, health care professionals are not experienced in using inhalers. This study assessed whether internal medicine residents used common inhalers correctly and whether a single teaching session successfully improved their performance. METHODS: We evaluated 142 internal medicine residents from six university hospitals in Korea for their techniques with three different inhaler devices: a metered dose inhaler (MDI), Diskus, and Turbuhaler. We assessed whether participants completed each step in using the three inhalers and classified overall performance as good, adequate, or inadequate for each inhaler type. To estimate the effect of a single teaching session, reassessment was performed 2 months after education. RESULTS: Performance grade was inadequate for 50.7% of participants with a MDI, 43.0% for Diskus, and 51.4% for Turbuhaler. An early year of residency was associated significantly with inappropriate technique for Diskus (p = 0.003), but not for MDI and Turbuhaler. After a single teaching session, overall skills improved significantly for all three inhalers. The proportion of subjects with good or adequate skill changed notably from 39.7% to 83.8% for MDI (p = 0.001), from 50.0% to 86.8% for Diskus (p = 0.001), and from 44.1% to 88.2% for Turbuhaler (p = 0.001). CONCLUSIONS: These findings demonstrate that a high proportion of internal medicine residents cannot use inhalers correctly and just a single teaching can effectively enhance their inhaler technique.


Subject(s)
Equipment Failure/statistics & numerical data , Internal Medicine/education , Internship and Residency , Metered Dose Inhalers , Nebulizers and Vaporizers , Adult , Age Factors , Clinical Competence/statistics & numerical data , Female , Humans , Korea , Male , Sex Factors
20.
Phys Med Biol ; 53(10): 2523-36, 2008 May 21.
Article in English | MEDLINE | ID: mdl-18424881

ABSTRACT

Tractography using diffusion tensor magnetic resonance imaging (DT-MRI) is a method to determine the architecture of axonal fibers in the central nervous system by computing the direction of greatest diffusion in the white matter of the brain. To reduce the noise in DT-MRI measurements, a tensor-valued median filter, which is reported to be denoising and structure preserving in the tractography, is applied. In this paper, we proposed the successive Fermat (SF) method, successively using Fermat point theory for a triangle contained in the two-dimensional plane, as a median filtering method. We discussed the error analysis and numerical study about the SF method for phantom and experimental data. By considering the computing time and the image quality aspects of the numerical study simultaneously, we showed that the SF method is much more efficient than the simple median (SM) and gradient descents (GD) methods.


Subject(s)
Image Processing, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Diffusion , Time Factors
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