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Although numerous studies have shown an association between alcohol consumption and cancer, how changes in drinking behavior increase or decrease the incidence of cancer is not well understood.To investigate the association between the reduction, cessation, or increase of alcohol consumption and the development of alcohol-related cancers and all cancers.This population-based cohort study analyzed adult beneficiaries in the Korean National Health Insurance Service. Participants (aged ≥40 years) included those who underwent a national health screening in both 2009 and 2011 and had available data on their drinking status. Data were analyzed from April 16 to July 6, 2020.Alcohol consumption level, which was self-reported by participants in health screening questionnaires, was categorized into none (0 g/d), mild (15 g/d), moderate (15-29.9 g/d), and heavy (≥30 g/d) drinking. Based on changes in alcohol consumption level from 2009 to 2011, participants were categorized into the following groups: nondrinker, sustainer, increaser, quitter, and reducer.The primary outcome was newly diagnosed alcohol-related cancers (including cancers of the head and neck, esophagus, colorectum, liver, larynx, and female breast), and the secondary outcome was all newly diagnosed cancers (except for thyroid cancer).Among the 4 513 746 participants (mean [SD] age, 53.6 [9.6] years; 2 324 172 [51.5%] men), the incidence rate of cancer was 7.7 per 1000 person-years during a median (IQR) follow-up of 6.4 (6.1-6.6) years. Compared with the sustainer groups at each drinking level, the increaser groups had a higher risk of alcohol-related cancers and all cancers. The increased alcohol-related cancer incidence was associated with dose; those who changed from nondrinking to mild (adjusted hazard ratio [aHR], 1.03; 95% CI, 1.00-1.06), moderate (aHR, 1.10; 95% CI, 1.02-1.18), or heavy (aHR, 1.34; 95% CI, 1.23-1.45) drinking levels had an associated higher risk than those who did not drink. Those with mild drinking levels who quit drinking had a lower risk of alcohol-related cancer (aHR, 0.96; 95% CI, 0.92-0.99) than those who sustained their drinking levels. Those with moderate (aHR, 1.07; 95% CI, 1.03-1.12) or heavy (aHR, 1.07; 95% CI, 1.02-1.12) drinking levels who quit drinking had a higher all cancer incidence than those who sustained their levels, but when quitting was sustained, this increase in risk disappeared. Compared with sustained heavy drinking, reduced heavy drinking levels to moderate levels (alcohol-related cancer: aHR, 0.91 [95% CI, 0.86-0.97]; all cancers: aHR, 0.96 [95% CI, 0.92-0.99]) or mild levels (alcohol-related cancer: aHR, 0.92 [95% CI, 0.86-0.98]; all cancers: aHR, 0.92 [95% CI, 0.89-0.96]) were associated with decreased cancer risk.Results of this study showed that increased alcohol consumption was associated with higher risks for alcohol-related and all cancers, whereas sustained quitting and reduced drinking were associated with lower risks of alcohol-related and all cancers. Alcohol cessation and reduction should be reinforced for the prevention of cancer.

Macrolide-resistant Mycoplasma pneumoniae (MRMP) has become prevalent in children. This study investigated the clinical and laboratory variables of MRMP and macrolide-sensitive M. pneumoniae (MSMP) and identified factors associated with prolonged hospital admission in children.A prospective multicenter study was conducted in 1063 children18 years old in July 2018-June 2020. The 454 had a positive M. pneumoniae polymerase chain reaction assay.Most subjects had MRMP (78.4%), and all mutated strains had the A2063G transition. We defined MRMP* (n = 285) as MRMP pneumonia requiring admission and MSMP* (n = 72) as MSMP pneumonia requiring admission. Patients with MRMP pneumonia were older, more likely to have segmental/lobar pneumonia, and had more febrile days than those with MSMP pneumonia. C-reactive protein (CRP), lactate dehydrogenase (LDH), and percentage neutrophils were more strongly associated with MRMP* than MSMP* groups. Percentage neutrophils, CRP, and alanine aminotransferase significantly changed between admission and follow-up measurements in patients with MRMP* (P 0.05). The duration of admission positively correlated with the number of febrile days after initiation of antibiotic medication and laboratory variables (white blood cell count, CRP, and aspartate aminotransferase [AST]) (P 0.05). Random forest analysis indicated that the number of febrile days after initiation of antibiotic medication, AST, and percentage neutrophils at admission was over five.This study indicated that children with M. pneumoniae pneumonia with a higher number of febrile days after initiation of antibiotic medication, AST, and percentage neutrophils at admission were more likely to have prolonged admission duration.

The level of pollen in Korea has increased over recent decades. Research suggests that oral allergy syndrome (OAS) may be more frequent in childhood than previously recognized. We aimed to investigate the prevalence and characteristics of OAS in children aged 6-10 years from a general-population-based birth cohort.We analyzed 930 children from the cohort for childhood origin of asthma and allergic diseases (COCOA). Allergic diseases were diagnosed annually by pediatric allergists. The skin prick tests were performed with 14 common inhalant allergens and four food allergens for the general population of children aged 3 and 7 years.Of the 930 eligible children, 44 (4.7%) aged 6-10 years were diagnosed with OAS. The mean age at onset was 6.74 years. OAS prevalence was 7.2% among children with allergic rhinitis (AR) and 19.1% among those with pollinosis, depending on comorbidity. OAS was more prevalent in schoolchildren with atopic dermatitis, food allergy, and sensitization to food allergens and grass pollen in early childhood. In schoolchildren with AR, only a history of food allergy until the age of 3 years increased the risk of OAS (aOR 2.971, 95% CI: 1.159-7.615).Food allergy and food sensitization in early childhood were associated with OAS in schoolchildren with AR. Further study is required to elucidate the mechanism by which food allergy in early childhood affects the development of OAS.

Printable organic sensors fabricated from solution-processed π-conjugated polymers (π-CPs) are promising candidates to detect volatile organic compounds (VOCs) due to the intriguing physical, chemical and electronic properties of π-CPs. These devices, often termed organic chemiresistors, require good sensing capabilities to transduce stimuli from specific VOCs at low concentrations into analytical electric signals. However, discriminating such VOCs using organic chemiresistors has proven very challenging. Herein, we report that the molecular-level electrochemical doping of π-CPs with solid-state ionic liquids (SILs) significantly improves their electrical conductivity (∼10−1 S cm−1) and selective VOC interactions, which can be manipulated through different π-CPs:SIL blend ratios. These characteristics enable the fine discrimination of VOCs at concentrations in the parts-per-billion (ppb) range under low power consumption (

Background: The level of pollen in Korea has increased over recent decades. Research suggests that pollen-food allergy syndrome (PFAS) may be more frequent in childhood than previously recognized. We aimed to investigate the prevalence and characteristics of PFAS in children aged 6–10 years from a general population-based birth cohort. Methods: We analyzed 930 children from the COhort for Childhood Origin of Asthma and allergic diseases (COCOA) birth cohort. Allergic diseases were diagnosed annually by pediatric allergists. The skin prick tests were performed with 14 common inhalant allergens and four food allergens for children aged 3 and 7 years. Results: Of the 930 eligible children, 44 (4.7%) aged 6–10 years were diagnosed with. The mean age at onset was 6.74 years. PFAS prevalence was 7.2% among children with allergic rhinitis (AR) and 19.1% among those with pollinosis, depending on comorbidity. PFAS was more prevalent in schoolchildren with atopic dermatitis, food allergy, and sensitization to food allergens and grass pollen in early childhood. In schoolchildren with AR, only a history of food allergy before 3 years increased the risk of PFAS (aOR 2.971, 95% CI: 1.159–7.615). Conclusion: Food allergy and food sensitization in early childhood was associated with PFAS in schoolchildren with AR. Further study is required to elucidate the mechanism by which food allergy in early childhood affects the development of PFAS.

Background Respiratory infection in children is a major disease that ranks high in outpatient and inpatient cases. In particular, the causes of community acquired pneumonia (CAP) vary depending on the individual susceptibility, epidemiological characteristics of the community, and season, and it is difficult to obtain samples for microbiological diagnosis. This study analysis that laboratory surveillance network of pathogen for pediatric CAP by linking the national community-based hospital and clinics and the Centers for Disease Control and Prevention (KCDC) to identify the distribution trend and prevalence of causative pathogens and to prevent antibiotic resistance of bacterial pathogens. Method The monitoring network was composed of the 28 secondary and tertiary medical institutions based on the national community, and the 24-month prospective study operated a community monitoring network for CAP in children. Results A total of 1023 cases were registered for nasopharyngeal aspirate or sputum in patients with CAP, and 711 cases (69.5%) were isolated by culture, S. aureus 131 cases (12.8%), S. pneumonia 92 cases (9%), H. influenzae 20 cases (2%). PCR of atypical pneumonia revealed 422 cases of M. pneumoniae (41.3%), 5 cases of C. pneumonia (0.5%), and 5 case (0.5%) of B. pertussis. Respiratory virus multiplex PCR test showed positive rates in 65.7%, human rhinovirus 312 (30.5%), RSV(A+B) 212 (20.7%), Adenovirus 123 (12%), Influenza (A+B) 53 (7.8%), CoV (OC43+NL63+229E) 69 (6.7%), HMPV 81 (7.9%), HBoV 51 (5%), PIV (1+2+3+4) 65 (6.4%) and HEV 30 (2.9%) Conclusion It will identify the pathogens that cause respiratory infections, and analyze the current status of antibiotic resistance to provide scientific evidence for management policies of domestic respiratory infection. Also, in preparation for the new epidemic, including COVID19, monitoring of respiratory infections in children and adolescents, especially community pneumonia, has become more important, and research should be continuously conducted in the future. The location and extent of involvement in the medulla were the most important factors associated with the severity of dysphagia after LMI.

Haploid breeding is an effective method of shortening the breeding period of plants. In this study, to develop a haploid breeding technique, optimum conditions of the culture medium were investigated for anther-derived callus induction in the strawberry cultivar Seolhyang. The effects of the culture medium type, myo-inositol, auxin and cytokinin combination treatment, silver nitrate (AgNO3), and ferric ethylenediaminetetraacetic acid (Fe-EDTA) on anther-derived callus induction were analyzed. Anthers were incubated in Murashige and Skoog (MS) medium, Gamborg B5 medium (B5), and Lichter medium (NLN) for 8 weeks. Each culture medium had 0.4 mg∙L–1 of 6-benzyladenine (BA), 0.1 mg∙L−1 of indole-3 acetic acid (IAA), and 2.0 mg∙L−1 of 2,4-dichlorophenoxyacetic acid (2,4-D) added to it. Results showed that MS medium was most effective in callus induction. When 100 mg∙L−1 of myo-inositol was added to each medium, the callus induction rate increased. Auxin and cytokinin combination treatment was more effective with the addition of 0.4 mg∙L−1 of BA, 0.1 mg∙L−1 of IAA, and 2.0 mg∙L−1 of 2,4-D to MS medium compared to the addition of 0.1 mg∙L−1 of BA, 2.0 mg∙L−1 of IAA, and 0.4 mg∙L−1 of 2,4-D. With AgNO3 treatment, the highest callus induction rate was found at a concentration of 25 mg∙L−1. The callus induction rate increased as the AgNO3 concentration increased; however, a significant decrease was seen at 30 mg∙L−1. In the case of Fe-EDTA, the most effective concentration for callus induction was 25 mg∙L−1. Therefore, supplementing myo-inositol, AgNO3 and Fe-EDTA can help in anther-derived callus induction in Seolhyang strawberries. Key words: Anther culture, auxin, B5 medium, callus induction, cytokinin, haploid breeding, NLN medium.

Diabetes mellitus (DM) often coexists in elderly hypertrophic cardiomyopathy (HCM) patients; however, its impact on clinical outcomes is unclear.We compared clinical outcomes according to the presence of DM in a nationwide HCM cohort.In 9,883 HCM subjects (mean age 58.5 ± 13.1, men 71.7%), 1,327 (13.4%) had DM. During follow-up (mean 5.9 ± 2.5 years), end-stage renal disease (ESRD) progression, coronary events (myocardial infarction, coronary revascularization), heart failure (HF), cardiovascular mortality, and all-cause mortality occurred in 80 (0.8%), 365 (3.7%), 1,558 (15.8%), 354 (3.6%), and 877 (8.9%) subjects, respectively. DM HCM subjects had significantly higher risks of ESRD progression (HR 3.49, 95% CI 2.20-5.54) and HF (HR 1.15, 95% CI 1.01-1.32) compared to non-DM HCM subjects, independent of age, sex, ischemic heart disease, atrial fibrillation, and other comorbidities. There was a tendency for greater risk of ESRD progression, HF, and all-cause death in subjects with more advanced stage of DM (p-for-trend 0.05 for all). Insulin-treated DM was associated with the highest risk.DM HCM subjects have higher risk of ESRD progression and HF. Considering the extended life expectancy of HCM and increasing number of elderly HCM subjects, active surveillance and management of DM-related outcomes should be highlighted.

Mycoplasma pneumoniae is a major causative pathogen of community-acquired pneumonia in children, and the treatment of choice is macrolides. There is an increasing trend in reports of refractory clinical responses despite macrolide treatment due to the emergence of macrolide-resistant M. pneumoniae. Early discrimination of macrolide-refractory M. pneumoniae pneumonia (MrMP) from macrolide-sensitive M. pneumoniae pneumonia (MSMP) is vital; however, testing for macrolide susceptibility at the time of admission is not feasible. This study aimed to identify the characteristics of MrMP in Korean children, in comparison with those of MSMP. In this multicenter study, board-certified pediatric pulmonologists at 22 tertiary hospitals reviewed the medical records from 2010 to 2015 of 5294 children who were hospitalized with M. pneumoniae pneumonia and administered macrolides as the initial treatment. One-way analysis of variance and the Kruskal-Wallis test were used to compare differences between groups. Of 5294 patients (mean age, 5.6 years) included in this analysis, 240 (4.5%), 925 (17.5%), and 4129 (78.0%) had MrMP, macrolide-less effective M. pneumoniae pneumonia, and MSMP, respectively. Compared with the MSMP group, the MrMP group had a longer fever duration, overall (13.0 days) and after macrolide use (8.0 days). A higher proportion of MrMP patients had respiratory distress, pleural effusion, and lobar pneumonia. The mean aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and C-reactive protein levels were the highest in the MrMP group, along with higher incidences of extrapulmonary manifestations and atelectasis (during and post infection). Pre-existing conditions were present in 17.4% (n = 725/4159) of patients, with asthma being the most common (n = 334/4811, 6.9%). This study verified that MrMP patients show more severe initial radiographic findings and clinical courses than MSMP patients. MrMP should be promptly managed by agents other than macrolides.

Stretchable conductive materials have received great attention owing to their potential for realizing next-generation stretchable electronics. However, the simultaneous achievement of excellent mechanical stretchability and high electrical conductivity as well as cost-effective fabrication has been a significant challenge. Here, we report a highly stretchable and highly conducting polymer that was obtained by incorporating an ionic liquid. When 1-ethyl-3-methylimidazolium tetracyanoborate (EMIM TCB) was added to an aqueous conducting polymer solution of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), it was found that EMIM TCB acts not only as a secondary dopant but also as a plasticizer for PEDOT:PSS, resulting in a high conductivity of >1000 S cm–1 with stable performance at tensile strains up to 50% and even up to 180% in combination with the prestrained substrate technique. Consequently, by exploiting the additional benefits of high transparency and solution-processability of PEDO...

Background: Community–acquired pneumonia (CAP) is one of the leading worldwide causes of childhood morbidity and mortality and its disease burden is affected by age and etiologies with time-dependent changes. We aimed to investigate the annual and seasonal patterns in etiologies of pediatric CAP requiring hospitalization. Methods: We conducted a retrospective study in 30,994 children (0-18 years old) with CAP between 2010 and 2015 at 23 nationwide hospitals in Korea. Mycoplasma pneumoniae (MP) pneumonia was clinically classified into macrolide-sensitive MP, macrolide-less effective MP (MLEP) and macrolide-refractory MP (MRMP) based on fever duration after initiation of macrolide treatment, regardless of the results of in vitro macrolide sensitivity tests. Results: MP and respiratory syncytial virus (RSV) were the two most commonly identified pathogens of CAP. With the two epidemics of MP pneumonia (2011 and 2015), the rates of clinical MLEP and MRMP pneumonia showed increasing trends of 36.36% of the total MP pneumonia. In children less than 2 years of age, RSV (34.01%) was the most common cause of CAP, followed by MP (9.44%), whereas MP was the most common cause of CAP in children 2-18 years of age. Systemic corticosteroid was most commonly administered in MP pneumonia. The rate of hospitalization in intensive care unit was highest for RSV pneumonia, and ventilator care was most commonly needed in cases of adenovirus pneumonia. Conclusions: The present study provides fundamental data for establishment of public health policies to decrease disease burden due to CAP as well as for improvement of pediatric health.

Background Bronchiectasis is a chronic pulmonary disease characterized by progressive and irreversible bronchial dilatation. The aim of the present study was to investigate the etiologies and clinical features of bronchiectasis in Korean children. Methods We performed a retrospective review of the medical records for children diagnosed with bronchiectasis between 2000 and 2017 at 28 secondary or tertiary hospitals in South Korea. Results A total of 387 cases were enrolled. The mean age at diagnosis was 9.2 ± 5.1 years and 53.5% of the patients were boys. The most common underlying cause of bronchiectasis was preexisting respiratory infection (55.3%), post-infectious bronchiolitis obliterans (14.3%), pulmonary tuberculosis (12.3%), and heart diseases (5.6%). Common initial presenting symptoms included chronic cough (68.0%), recurrent pneumonia (36.4%), fever (31.1%), and dyspnea (19.7%). The most predominantly involved lesions were left lower lobe (53.9%), right lower lobe (47.1%) and right middle lobe (40.2%). No significant difference was observed in the distribution of these involved lesions by etiology. The forced expiratory volume in 1 s (FEV1) levels were lowest in cases with interstitial lung disease-associated bronchiectasis, followed by those with recurrent aspiration and primary immunodeficiency. Conclusions Bronchiectasis should be strongly considered in children with chronic cough and recurrent pneumonia. Long-term follow-up studies on pediatric bronchiectasis are needed to further clarify the prognosis and reduce the disease burden in these patients.

PURPOSE: Pollen-food allergy syndrome (PFAS) is an immunoglobulin E (IgE)-mediated allergy in pollinosis patients caused by raw fruits and vegetables and is the most common food allergy in adults. However, there has been no nationwide study on PFAS in Korea. In this study, we investigated the prevalence and clinical characteristics of PFAS in Korea. METHODS: Twenty-two investigators participated in this study, in which patients with allergic rhinoconjunctivitis and/or bronchial asthma with pollen allergy were enrolled. The questionnaires included demographic characteristics, a list of fruits and vegetables, and clinical manifestations of food allergy. Pollen allergy was diagnosed by skin prick test and/or measurement of the serum level of specific IgE. RESULTS: A total of 648 pollinosis patients were enrolled. The prevalence of PFAS was 41.7% (n = 270). PFAS patients exhibited cutaneous (43.0%), respiratory (20.0%), cardiovascular (3.7%) or neurologic symptoms (4.8%) in addition to oropharyngeal symptoms. Anaphylaxis was noted in 8.9% of the PFAS patients. Seventy types of foods were linked to PFAS; e.g., peach (48.5%), apple (46.7%), kiwi (30.4%), peanut (17.4%), plum (16.3%), chestnut (14.8%), pineapple (13.7%), walnut (14.1%), Korean melon (12.6%), tomato (11.9%), melon (11.5%) and apricot (10.7%). Korean foods such as taro/taro stem (8.9%), ginseong (8.2%), perilla leaf (4.4%), bellflower root (4.4%), crown daisy (3.0%), deodeok (3.3%), kudzu root (3.0%) and lotus root (2.6%) were also linked to PFAS. CONCLUSIONS: This was the first nationwide study of PFAS in Korea. The prevalence of PFAS was 41.7%, and 8.9% of the PFAS patients had anaphylaxis. These results will provide clinically useful information to physicians.

Purpose: Croup is known to have epidemics in seasonal and biennial trends, and to be strongly associated with epidemics of para influenza virus. However, seasonal and annual epidemics of croup have not been clearly reported in Korea. This study aimed to ex amine the seasonal/annual patterns and etiologies of childhood croup in Korea during a consecutive 6-year period. Methods: Pediatric croup data were collected from 23 centers in Korea from 1 January 2010 to 31 December 2015. Electronic medi cal records, including multiplex reverse transcription polymerase chain reaction (RT-PCR) results, demographics and clinical informa tion were cross-sectionally reviewed and analyzed. Results: Overall, 2,598 childhood croup patients requiring hospitalization were identified during the study period. Among them, a total of 927 who underwent RT-PCR were included in the analysis. Males (61.5%) predominated, and most (63.0%) of them were younger than 2 years of age (median, 19 months; interquartile range, 11-31 months). Peak hospitalization occurred in 2010 and 2012 in even-numbered years, and parainfluenza virus (PIV, 39.7%) was the most common cause of childhood croup requiring hos pitalization, followed by respiratory syncytial virus (14.9%), human rhinovirus (12.5%), Mycoplasma pneumonaie (10.6%), and human coronavirus (7.3%). Conclusion: It is concluded that croup hospitalization has a biennial pattern in even-numbered years. PIV may be the most com mon cause of childhood croup; however, croup epidemics could be attributed to other viruses. (Allergy Asthma Respir Dis 2019;7:78-85)

Purpose: The nature of allergic rhinitis (AR) in preschool aged children remains incompletely characterized. This study aimed to investigate the prevalence of AR and its associated risk factors in preschool-aged children and to assess the clinical utility of fractional exhaled nitric oxide (FeNO). Methods: This general population-based, cross-sectional survey included 933 preschool-aged (3- to 7-year-old) children from Korea. Current AR was defined as having nasal symptoms within the last 12 months and physician-diagnosed AR. Results: The prevalence of current AR in preschool children was 17.0% (156/919). Mold exposure (adjusted odds ratio [aOR], 1.67; 95% confidence interval [CI], 1.15-2.43) and the use of antibiotics (aOR, 1.97; 95% CI, 1.33-2.90) during infancy were associated with an increased risk of current AR, whereas having an older sibling (aOR, 0.52; 95% CI, 0.35-0.75) reduced the risk. Children with current atopic AR had significantly higher geometric mean levels of FeNO compared to those with non-atopic rhinitis (12.43; range of 1standard deviation [SD], 7.31-21.14 vs 8.25; range of 1SD, 5.62-12.10, P=0.001) or non-atopic healthy children (8.58; range of 1SD, 5.51-13.38, P

This study represents the first epidemiological study based on the national registry of primary immunodeficiencies (PID) in Korea. Patient data were collected from 23 major hospitals. A total of 152 patients with PID (under 19 yr of age), who were observed from 2001 to 2005, have been entered in this registry. The period prevalence of PID in Korea in 2005 is 11.25 per million children. The following frequencies were found: antibody deficiencies, 53.3% (n = 81), phagocytic disorders, 28.9% (n = 44); combined immunodeficiencies, 13.2% (n = 20); and T cell deficiencies, 4.6% (n = 7). Congenital agammaglobulinemia (n = 21) and selective IgA deficiency (n = 21) were the most frequently reported antibody deficiency. Other reported deficiencies were common variable immunodeficiencies (n = 16), X-linked agammaglobulinemia (n = 15), IgG subclass deficiency (n = 4). Phagocytic disorder was mostly chronic granulomatous disease. A small number of patients with Wiskott-Aldrich syndrome, hyper-IgE syndrome, and severe combined immunodeficiency were also registered. Overall, the most common first manifestation was pneumonia. This study provides data that permit a more accurate estimation PID patients in Korea.

Honeycomb-patterned polyvinypyrrolidone (PVP) thin films coated with nanometer-sized silver particles were prepared using honeycomb-patterned polystyrene (PS) template films fabricated by casting a polystyrene solution under humid condition. Silver was first metallized on the patterned PS films via silver nitrate () reduction using tetrathiafulvalene (TTF) and a small amount of PVP as the reductant and dispersing agent, respectively. The effects of , TTF, and PVP solution concentrations during the reduction process in acetonitrile were determined to obtain a uniform silver-coated honeycomb-patterned PS film. Second, the silver-metallized patterned porous PS films were filled with high PVP concentration solutions via the spincoating process. Silver-coated patterned PVP films were obtained by peeling off the PVP layer from the template PS film after drying. The results show that the honeycomb-patterned PVP films uniformly coated with silver particles are conveniently obtained using the silver-coated patterned PS template, although the direct fabrication of these films using water droplets under humid conditions was not feasible because of the water solubility of PVP.

Poly(N-vinylcarbazole) (PVK) composites containing different concentrations of cellulose triacetate (CTA) were synthesized through oxidative polymerization of N-vinylcarbazole with ferric chloride. Characterization and thermal stability of the synthesized composite were investigated using Fourier transform infrared (FTIR) and ultraviolet—visible (UV—Vis) spectroscopy, and thermogravimetric analysis (TGA), respectively. Surface morphology of the synthesized composites was studied using both scanning and transmission electron microscopy. Well-ordered porous films of the polymer composites were fabricated by evaporation of the composite solution dissolved in a volatile solvent under humid conditions. The PVK—CTA composite formed a highly well-ordered honeycomb pattern with the appropriate concentration of CTA in the absence of any kind of amphiphilic copolymer to stabilize the air—water interface. Findings of this study indicate that uniformly dispersed CTA is responsible for the stability of the air—water interface in the composite solution, thus enabling the formation of a highly ordered polymer film.

Polymer composites containing alginate (AL) and treated multiwalled carbon nanotubes (TMWNT) were prepared by dispersing different weight percentages of TMWNT. The resulting composites were characterized by Fourier transform infrared spectroscopy (FTIR) and UV-vis spectroscopy (UV). The morphology of the composites was examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and the thermal stability and crystallinity embedded in the composites were analyzed by thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The results of the characterization, morphology, thermal stability as well as diffraction studies clearly show that the alginate-TMWNT (AL-NT) composites are formed by dispersing the TMWNT into the AL polymer matrix. In addition, the AC electrical conductivity of the composites was also studied in the frequency range, 350 KHz-2.3 MHz. The frequency and temperature dependent AC conductivity of the AL-NT composites was strongly affected by the dispersed concentration of TMWNT.

Cellulose triacetate (CTA) and multiwalled carbon nanotube (MWNT) composite films were prepared by dispersing different weight percentages of MWNTs into a CTA solution. These composite blends were characterized by UV–vis spectroscopy (UV), and their surface mophology, thermal stability, and amended crystallinity were determined by atomic force microscopy (AFM), thermogravimetric analysis (TGA), and X-ray diffraction (XRD), respectively. Measurements of the complex impedance of the composite samples were made in the form of films. Sheets prepared from conventional techniques were used to study microwave absorption in the microwave range of 2–12 GHz, and the effects of sample thickness on microwave absorption were investigated. The experimental results show that the electrical conductivity of composites increases with the increase in MWNT loading without a percolation threshold. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers

Poly-N-vinylcarbazole–polyaniline (PANI) composites were synthesized using different loading concentration of aniline (0.025–0.1 M) for their microwave absorption characteristics. The obtained composites were studied by Fourier transform infrared spectroscopy, thermogravimetric analysis technique, and atomic force microscope for their chemical structure, thermal stability, and the surface modifications, respectively. The conductivity increased much with the increase of aniline concentration in the composites. The composite sheets exhibited a strong microwave absorption in the microwave range of 1–10 GHz and achieved a maximum absorption value of 33 dB. The position of absorbing peak shows a mixed trend moving from lower to higher and again to lower with an increasing the concentration of aniline in the poly-N-vinylcarbazole–PANI. The new polymer composite exhibited an appreciable electromagnetic interference shielding efficiency compared with the previously reported PANI composites. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers

The polypyrrole (PPy) — alginate (Ag) blend films were synthesized using different wt% of Ag and characterized by Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible (UV-vis) spectroscopy. The morphology was examined by transmission electron microscopy (TEM). The electrical conductivity was determined by studying the I–V characteristics at temperatures ranging from 300–500 K. The results are shown by measuring the dependence of the current on the field, temperature, and blending compositions in the form of the I–V characteristics, and the analysis was made by interpretation of the Poole-Frenkel, Schottky ln (J) vs. T plots. For individual polymers, the conduction mechanism was observed to be a Poole-Frenkel type. After the polymer blend was formed, charge conduction appeared to be the Poole-Frenkel mechanism at both lower and higher temperatures. These results suggest that the Pool-Frenkel mechanism is mainly responsible for the observed conduction. The conductivity of the films increased with increasing alginate wt% in the blend and the mobility of the charge carriers increased with increasing alginate wt% concentration in the blend.

Allergen sensitization and airway hyperresponsiveness (AHR) are the most important characteristics of bronchial asthma and their correlation has been speculated.We attempted to investigate the relationship between sensitization to allergens and AHR to methacholine in Korean high school students.A questionnaire survey, methacholine bronchial provocation tests, and skin-prick tests for 16 major allergens were performed on 724 students. The mean age of participants was 15.79 ± 0.40 years old. Serum total immunoglobulin E (IgE) and the fraction of blood eosinophils were measured.AHR (PC(20)16 mg/ml) was present in 12.3%. Log total IgE was higher in AHR-positive group than negative group (4.22 ± 1.55, 3.70 ± 1.33, P = 0.001). Three hundred eighty-four students (53.0%) were sensitized to more than one allergen, and among them Dermatophagoides pteronyssinus (Der p, 295 students, 40.7%) and Dermatophagoides farinae (Der f, 301 students, 41.6%) were most common. The risk of AHR development was high in the group who had sensitization to one allergen (adjusted odds ratio [aOR] = 1.97, 95% confidence interval [CI]: 1.13-3.44, P = 0.018) and to more than two allergens (aOR = 2.94, 95% CI: 1.32-6.57, P = 0.009). Among the specific allergens, AHR was developed in those who were sensitized to Der f (aOR = 1.73, 95% CI: 1.04-2.86, P = 0.033), dog dander (aOR = 3.97, 95% CI: 1.67-9.51, P = 0.002), and Alternaria (aOR = 3.19, 95% CI: 1.24-6.41, P = 0.016). In the groups with high IgE (300 IU/ml) and high eosinophil fraction (4%), AHR was more developed than groups who were low in each (aOR = 2.73, 95% CI: 1.15-6.51, P = 0.023; aOR = 10.82, 95% CI: 3.33-35.08, P = 0.001).The risk of AHR development was closely linked with allergen sensitization itself, and the number or types of sensitized allergens such as indoor and fungal allergens in Korean young adolescents.

The formation of diverse spiral waves was studied in a polyacrylamide gel membrane with ruthenium(4-vinyl-4'-methyl-2,2'-bipyridine)bis(2,2'-bipyridine)bis(hexafluorophosphate) by a gas-free Belousov-Zhabotinisky (BZ) reaction system containing 1,4-cyclohexanedione (1,4-CHD). The gel membrane was found to be receptive for observing propagating waves since a clearer wave-train is obtained during a long reaction time without any disturbance from the immobilized metal catalyst which can be dissolved into the highly acidic solution of the BZ system. The distinctive waves in the system basically depend on both Br0 3 and 1,4-CHD in the initial phase, and are influenced by the intensity of illumination of visible light.

A new functional amphiphilic polymer (AP) containing ruthenium tris(bipyridyl) photosensitizer was synthesized and a honeycomb-patterned film was fabricated by casting a polystyrene solution and different concentrations of AP under humid conditions. The amphiphilic copolymer was obtained by the radical copolymerization of ruthenium (4-vinyl-4′-methyl-2,2′-bipyridine)bis(2,2′-bipyridine)bis(hexaflurophosphate) with N-dodecylacrylamide and N-isopropylacrylamide. Without the addition of AP, irregularly ordered porous films were obtained, while adding AP in the casting solution resulted in highly ordered honeycomb-patterned films. In addition, the pore diameter and height of the porous structure increased with the increase of AP amount in the solution. However, an excessive amount of AP induced an irregularly structured pattern with small pore sizes.

Cellulose triacetate (CTA) was doped with poly(N-vinylcarbazole) (PVK) via the oxidative polymerization of N-vinylcarbazole with ferric chloride to form polymer blends. Langmuir–Schaefer (LS) films of the polymer blends were fabricated. The morphology of the cellulose triacetate-poly(N-vinylcarbazole) (PC) blends were analyzed using transmission electron microscopy. The pressure–area isotherm of PC blends revealed the possibility of compact monolayer formation at air–water interface. The voltammetric investigation of PC blends showed an appreciable electrochemical behavior. The photoinduced charge transfer across a donor/acceptor hybrid interface provided an effective method to study the photoelectrochemical properties of the PC polymer films.

Objective: Pain assessment usually involves the use of subjective pain scales; as their use may be associated with inter-/intra-observer bias, objective pain measurements, such as assessment of cortisol response to pain, are needed. This study aimed to compare the efficacy of oral dextrose and a pacifier in neonatal pain control using an objective measurement of salivary cortisol level and subjective pain scoring. Methods: This prospective, randomized, partially blinded clinical trial included healthy newborns from a nursery (n=142). Blood was sampled using a lancet and newborns were randomly assigned to four groups by drawing lots: control (n=33), sterile water (n=35), 25% dextrose (n=35), and pacifier group (n=39). For all groups, neonatal infant pain scale, neonatal facial coding system, and premature infant pain profile scores were evaluated before, during, and 2 minutes after newborn screening test by two independent observers who watched recorded videos. Moreover, samples of saliva were collected before and 30 minutes after the pain procedure, and salivary cortisol level was measured using an enzyme-linked immunosorbent assay. Results: Subjective pain scores were not statistically different among the four groups before, during, and after blood sampling using a lancet. However, the salivary cortisol level in the 25% dextrose group was significantly lower than that in the other groups (P=0.045). Conclusion: Oral administration of 25% dextrose solution for pain control during the newborn screening test led to a significantly lower salivary cortisol level than the use of sterile water or a pacifier. However, no difference in pain scores was found among groups.

Despite the high expectation of deformable and see-through displays for future ubiquitous society, current light-emitting diodes (LEDs) fail to meet the desired mechanical and optical properties, mainly because of the fragile transparent conducting oxides and opaque metal electrodes. Here, by introducing a highly conductive nanofibrillated conducting polymer (CP) as both deformable transparent anode and cathode, ultraflexible and see-through polymer LEDs (PLEDs) are demonstrated. The CP-based PLEDs exhibit outstanding dual-side light-outcoupling performance with a high optical transmittance of 75% at a wavelength of 550 nm and with an excellent mechanical durability of 9% bending strain. Moreover, the CP-based PLEDs fabricated on 4 µm thick plastic foils with all-solution processing have extremely deformable and foldable light-emitting functionality. This approach is expected to open a new avenue for developing wearable and attachable transparent displays.