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1.
Heliyon ; 9(12): e22170, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38213576

ABSTRACT

Long Fiber Spray-up Molding (LFSM) deviates from the conventional approach in liquid composite molding (LCM) processes by utilizing extremely long chopped strands of fibers as the primary reinforcement material in its fabrication process. In LFSM, chopped fibers are impregnated with resin that is sprayed vertically downwards before reaching the mold surface. The spraying mechanism is mounted on an actuator, which is capable of spraying freely in any specified pattern or direction. Under LFSM, it is extremely difficult to fabricate a composite part with uniformly distributed fiber content throughout its volume. The consequences of the non-uniform fiber volume distribution arise from the fiber entanglement as the length of the fiber reaches up to 100 mm in LFSM. In this study, the effect of fiber entanglement during LFSM was analyzed through various approaches. This included measuring the coefficient of friction between fibers in contact and examining the correlation between fiber lengths and the number of intersections. Furthermore, the viscoelastic properties of the uncured composite part were assessed by experimenting with the influence of viscosity on fiber length during compression molding. The results were then computed, modeled, and visualized in MATLAB, considering variations in viscosity and fiber length, both before and after compression molding.

2.
Sci Rep ; 11(1): 15716, 2021 08 03.
Article in English | MEDLINE | ID: mdl-34344955

ABSTRACT

Pre- and post-transplantation anti-MICA antibody detection development are associated with an increased rejection risk and low graft survival. We previously generated HLA class I null HEK-293T using CRISPR/Cas9, while MICA and MICB genes were removed in this study. A panel of 11 cell lines expressing single MICA alleles was established. Anti-MICA antibody in the sera of kidney transplant patients was determined using flow cytometric method (FCM) and the Luminex method. In the 44 positive sera, the maximum FCM value was 2879 MFI compared to 28,135 MFI of Luminex method. Eleven sera (25%) were determined as positive by FCM and 32 sera (72%) were positive by the Luminex method. The sum of total MICA antigens, MICA*002, *004, *009, *019, and *027 correlation showed a statistically significant between the two methods (P = 0.0412, P = 0.0476, P = 0.0019, P = 0.0098, P = 0.0467, and P = 0.0049). These results demonstrated that HEK-293T-based engineered cell lines expressing single MICA alleles were suitable for measuring specific antibodies against MICA antigens in the sera of transplant patients. Studies of antibodies to MICA antigens may help to understand responses in vivo and increase clinical relevance at the cellular level such as complement-dependent cytotoxicity.


Subject(s)
Alleles , Histocompatibility Antigens Class I/genetics , Histocompatibility Antigens Class I/immunology , Gene Knockout Techniques , Genetic Engineering/methods , Graft Survival/immunology , HEK293 Cells , HLA Antigens/genetics , HLA Antigens/immunology , Histocompatibility Antigens Class I/metabolism , Humans , Kidney Transplantation
3.
Materials (Basel) ; 12(19)2019 Oct 04.
Article in English | MEDLINE | ID: mdl-31590247

ABSTRACT

Composites using dicyclopentadiene (DCPD) as a matrix have gained significant popularity owing to their excellent impact and chemical corrosion resistance. In the present study, experiments addressing the impact behavior of glass-fiber-reinforced DCPD were conducted to quantitatively evaluate its impact properties. The glass-fiber-reinforced polydicyclopentadiene composite utilized in impact tests was manufactured using structural reaction injection molding (S-RIM) because of its fast curing characteristics and low viscosity. The impact properties of the glass-fiber-reinforced DCPD (GF/DCPD) were quantitatively evaluated by varying its fiber content and decelerator solution. The impact properties of neat DCPD and GF/DCPD composites were examined with different amounts of decelerator solution under various temperatures from room temperature to cryogenic temperature to observe the ductile-to-brittle transition temperature (DBTT). With an increase in the fiber weight fraction of the GF/DCPD composite, the effect of the DBTT significantly decreased. However, the decreasing rate retarded as the weight fraction of the GF increased. The decreased DBTT with the addition of GF in the GF/DCPD can be attributed to the differences in the thermal expansion ratio and the interfacial force between neat DCPD and the fiber. A fractograph analysis demonstrates that the effect of the brittle (smooth) surface resulted in a lower impact absorbed energy when the temperature decreased, along with the increased amount of the decelerator.

4.
Obes Res Clin Pract ; 12(2): 146-157, 2018.
Article in English | MEDLINE | ID: mdl-29066025

ABSTRACT

Eating alone has been an emerging social concern in modern life. However, there is little research on the association between eating alone and Metabolic syndrome (MetS). We aimed to assess the association between eating alone and the MetS and to identify whether sociodemographic factors modify this association. This study included 7725 adults (≥19 years) who participated in the Korean National Health and Nutrition Examination Survey (KNHANES) 2013-2014. Multivariable logistic regression analysis was used for assessing the association of eating alone (none, 1 time/day, and ≥2 times/day) with MetS. The percentages of subjects with MetS were 30.4% in men and 24.2% in women. 20.8% of men and 29.2% of women ate alone ≥2 times/day. Individuals who ate alone 2 or more times per day showed higher frequency of living alone, having no spouse, skip meals, and less eating out (p<0.05). Women with eating alone ≥2 times/day had a crude OR of 1.29 (95% CI:1.08-1.53, p-trend=0.001) for MetS compared with women without eating alone. However, this association was no longer significant after adjustments for confounding factors. Eating alone ≥2 times/day was significantly associated with increase abdominal obesity (OR, 95% CI:1.45, 1.10-1.91, p-trend=0.039) and MetS (1.64, 1.28-2.10, p-trend=0.004) in men. Eating alone was associated with a higher likelihood of having a MetS in men without spouse as compared with those with spouse (OR for men without spouse 3.02, 95% CI:1.50-6.11 and OR for men with spouse 1.48, 95% CI:1.22-1.7, p-interaction=0.027). Our results indicate that eating alone may be a potential risk factor for MetS.


Subject(s)
Feeding Behavior/psychology , Metabolic Syndrome/epidemiology , Nutrition Surveys , Obesity, Abdominal/epidemiology , Adult , Aged , Blood Pressure , Female , Humans , Loneliness/psychology , Male , Metabolic Syndrome/etiology , Middle Aged , Obesity, Abdominal/etiology , Republic of Korea/epidemiology , Risk Factors , Social Behavior , Young Adult
5.
Infect Chemother ; 49(3): 230-235, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28608661

ABSTRACT

Campylobacter infection causes gastrointestinal symptoms such as abdominal pain or diarrhea. Occasionally, Campylobacter bacteremia affects immunocompromised patients; however, serious outcomes are known to be rare. Here, we present a case of a patient with Campylobacter bacteremia who had underlying liver cirrhosis. The patient had fever and diarrhea. These symptoms subsided after treatment with cefotaxime. Campylobacter jejuni was isolated in the blood culture after 10 days. In addition, previously reported cases of Campylobacter bacteremia in Asian countries were reviewed with respect to antimicrobial sensitivities.

6.
Medicine (Baltimore) ; 96(8): e6159, 2017 02.
Article in English | MEDLINE | ID: mdl-28225498

ABSTRACT

BACKGROUND: Infection-associated hemophagocytic syndrome (IAHS) is potentially a fatal disease caused by systemic infection complicated by hemophagocyticlymphohistiocytosis (HLH). Here, we report a case of HLH associated with dengue hemorrhagic fever (DHF) after a trip to Thailand. CASE SUMMARY: A 33-year-old healthy female patient presented with 3 days of fever, myalgia, and skin rash. Serotype 3 dengue virus was isolated. Clinical and laboratory findings fulfilled the criteria of HLH. After the initiation of corticosteroid therapy, the patient recovered and laboratory findings were normalized. CONCLUSION: It would be important to differentially diagnose dengue-associated HLH from severe DHF. Early recognition and initiation of steroid treatment would be crucial for the successful treatment of dengue fever complicated by HLH.


Subject(s)
Lymphohistiocytosis, Hemophagocytic/complications , Lymphohistiocytosis, Hemophagocytic/diagnosis , Severe Dengue/complications , Severe Dengue/diagnosis , Adrenal Cortex Hormones/therapeutic use , Adult , Diagnosis, Differential , Early Diagnosis , Female , Humans , Lymphohistiocytosis, Hemophagocytic/drug therapy , Lymphohistiocytosis, Hemophagocytic/pathology , Severe Dengue/drug therapy , Severe Dengue/pathology
7.
Infect Chemother ; 48(4): 294-301, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27883375

ABSTRACT

BACKGROUND: The World Health Organization recommends the surveillance of influenza-like illness (ILI) and severe acute respiratory infection (SARI) to respond effectively to both seasonal influenza epidemics and pandemics. In Korea, the "Hospital-based Influenza Morbidity and Mortality (HIMM)" surveillance system has been operated to monitor ILI and SARI occurrences. MATERIALS AND METHODS: A multi-center prospective observational study was conducted. Adult patients with acute respiratory infection (ARI) were enrolled during the 2011-12, 2012-2013, and 2013-2014 influenza seasons at the 10 university hospitals using the HIMM surveillance system. With respect to SARI and pneumonia development, risk profiles were analyzed in patients with ARI in Korea. RESULTS: A total of 5,459 cases were eligible for this analysis. Among 5,459 cases with ARI, 2,887 cases (52.9%) were identified that they had influenza infection. Among enrolled cases, 750 cases belonged to the SARI group, while 4,709 cases belonged to the non-SARI group. With respect to pneumonia development, 317 cases were accompanied by pneumonia, and 5,142 cases were not. Multivariate analyses revealed that the following factors were associated with an increased risk of SARI: Old age (≥65 years) (odds ratio [OR] 2.69, 95% confidence interval [CI] 2.2-3.32), chronic heart disease (CHD) (OR 2.24, 95% CI 1.68-2.98), cerebrovascular disease (CVD) (OR 1.49, 95% CI 1.05-2.10), chronic obstructive pulmonary disease (COPD) (OR 2.34, 95% CI 1.48-3.69), asthma (OR 2.33, 95% CI 1.62-3.36), chronic kidney disease (CKD) (OR 2.62, 95% CI 1.73-3.99), chronic liver disease (OR 1.71, 95% CI 1.04-2.81), and autoimmune diseases (OR 2.53, 1.57-4.08). Multivariate analyses revealed that the following factors were independent risk factors for pneumonia development: Old age (≥65 years) (OR 5.71, 95% CI 4.10-7.94), CHD (OR 1.54, 95% CI 1.07-2.22), COPD (OR 2.34, 95% CI 1.48-3.69), asthma (OR 2.33, 95% CI 1.62-3.36), CKD (OR 2.62, 95% CI 1.73-3.99), immunocompromised conditions (OR 3.12, 95% CI 1.47-6.62), and autoimmune diseases (OR 3.35, 95% CI 1.79-6.27). The risk of SARI and pneumonia was increased by the number of concurrent chronic medical conditions. CONCLUSION: The risk of SARI and pneumonia development among adult patient with ARI was significantly increased by the presence or number of concurrent chronic medical conditions in Korea.

8.
J Clin Virol ; 80: 33-5, 2016 07.
Article in English | MEDLINE | ID: mdl-27135388

ABSTRACT

BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne disease characterized by high fever, thrombocytopenia, leukopenia, and multiple organ failure and is caused by a novel bunyavirus. Human-to-human transmission has been reported previously, but the mode of transmission has not been clarified thoroughly. STUDY DESIGN: We identified a case of a 73-year-old woman with SFTS and performed a semi-quantitative real-time reverse transcription PCR (real-time RT-PCR) assay on her blood, tracheal aspirate, gastric aspirate and urine to detect SFTS virus (SFTSV). RESULTS: During 7-day hospitalization, all the serum samples showed positive Ct values lower than 35 in both the S and M segments, suggesting the presence of the SFTSV RNA. After initiation of plasma exchange, serum SFTSV load markedly decreased, but still remained positive. The SFTS viral RNA was also detected in other body fluids, including tracheal aspirate and gastric aspirate. CONCLUSION: These results suggest that droplet transmission can occur through close contact with infected patients.


Subject(s)
Body Fluids/virology , Phlebotomus Fever/virology , Phlebovirus/isolation & purification , Thrombocytopenia/virology , Aged , Blood/virology , Female , Gastrointestinal Tract/virology , Humans , Phlebovirus/genetics , RNA, Viral/analysis , Trachea/virology , Urine/virology , Virus Shedding
9.
J Infect Chemother ; 22(8): 515-20, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27234358

ABSTRACT

BACKGROUND: The prevalence of Serotype 6D Streptococcus pneumoniae was reported relatively high in South Korea. Since the introduction of 7-valent pneumococcal conjugate vaccine (PCV7), serotype replacement was observed. This study was designed to better clarify genetic diversity of pneumococcal serotype 6D and its clinical characteristics after introduction of PCV7 in 2000. METHODS: We performed serotyping analysis with 1298 pneumococcal isolates from clinical specimens in South Korea from 2004 to 2011. Multilocus sequence typing was performed, and minimal inhibitory concentration was determined for the available serotype 6D and nontypeable (NT) pneumococcal isolates during the 2006-2007 period. RESULTS: The proportion of serotype 6D pneumococci increased from 0.8% (2004-2007) to 2.9% (2008-2011) of all clinical pneumococcal isolates, accounting for 14.9% of serogroup 6 pneumococci in South Korea. NT pneumococci markedly increased to 13.3% during 2006-2007 in advance of the increase in serotype 6D. Among the 26 available serotype 6D pneumococcal isolates, ST282 was predominant (23 isolates, 88.5%). The STs of NT pneumococci (26 isolates) were diverse, but clonal complex 271 was the dominant clone. The oral penicillin non-susceptibility rate was 92.3% (24 among 26 isolates) for both serotype 6D and NT pneumococci. The ceftriaxone non-susceptibility rates of serotype 6D and NT pneumococci were 7.7% and 3.8%, respectively. CONCLUSION: ST228(6D) strain expanded, particularly among old adults with comorbidities in South Korea. Both antibiotic and PCV7 pressure might have contributed to the selective increase of NT and serotype 6D pneumococci.


Subject(s)
Pneumococcal Infections/microbiology , Streptococcus pneumoniae/genetics , Streptococcus pneumoniae/isolation & purification , Adolescent , Adult , Aged , Anti-Bacterial Agents/therapeutic use , Ceftriaxone/therapeutic use , Child , Child, Preschool , Female , Genetic Variation/genetics , Humans , Male , Microbial Sensitivity Tests/methods , Middle Aged , Multilocus Sequence Typing/methods , Pneumococcal Infections/drug therapy , Pneumococcal Infections/epidemiology , Pneumococcal Infections/immunology , Pneumococcal Vaccines/immunology , Republic of Korea/epidemiology , Serogroup , Serotyping/methods , Streptococcus pneumoniae/drug effects , Streptococcus pneumoniae/immunology , Vaccines, Conjugate/immunology , Young Adult
10.
Infect Chemother ; 48(1): 36-40, 2016 Mar.
Article in English | MEDLINE | ID: mdl-27104014

ABSTRACT

Human metapneumovirus is known to be similar to respiratory syncytial virus. Because of an incomplete protective immune response to new genotypes, re-infection occurs frequently, especially in the elderly. However, the clinical manifestations of human metapneumovirus need to be further characterized in adults. A 73-year-old woman presented to the emergency room with acute dyspnea, chest discomfort and influenza-like illness. The patient was diagnosed with human metapneumovirus infection, complicated by pneumonia and myopericarditis. With supportive care including oxygen supplementation, the patient recovered completely without any serious sequelae. Human metapneumovirus infection may contribute to the development of cardiovascular manifestations, particularly in the elderly population.

11.
J Infect Chemother ; 21(9): 672-9, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26212866

ABSTRACT

Early diagnosis of pneumococcal pneumonia facilitates appropriate antibiotic therapy. The urinary antigen test (UAT) is known to be useful for the diagnosis of pneumococcal pneumonia. This study aimed to evaluate the usefulness of UAT in the 13-valent pneumococcal conjugated vaccine (PCV13) era. Community-acquired pneumonia (CAP) cases aged ≥19 years were reviewed retrospectively. This study evaluated the utility of Streptococcus pneumoniae UAT (BinaxNOW(®) assay) for diagnosis of pneumococcal CAP, and the relation of the UAT positive rate to age, comorbidities, pneumonia severity, and pneumococcal serotypes. Among 752 microbiologically identified CAP cases, S. pneumoniae (36.7%) was the most common isolate, and of those cases, 56.4% were positive for UAT. UAT positivity varied by pneumococcal serotype (serotype 3, 50%; 9V/9A, 85%; 11A/11E, 54%; 14, 36.4%; 19A, 50%; and 23F, 37.5%), and was significantly increased since 2012, two years after introduction of PCV13. The positive rate of UAT was significantly related to CRP level (P = 0.007) and lobar pneumonia (P = 0.006), but not to age, co-morbidities or prior antibiotic therapy. In conclusion, urinary antigen detection varied depending on the S. pneumoniae serotype. In the PCV13 era, the serotype distribution of pneumococcal pneumonia may be changing, and the clinical usefulness of UAT needs to be monitored. The positive rate of UAT may be influenced by a localized bacterial burden and host reactions.


Subject(s)
Antigens, Bacterial/urine , Pneumonia, Pneumococcal/diagnosis , Pneumonia, Pneumococcal/urine , Streptococcus pneumoniae/classification , Streptococcus pneumoniae/immunology , Adult , Age Factors , Aged , C-Reactive Protein/metabolism , Community-Acquired Infections/diagnosis , Community-Acquired Infections/urine , Comorbidity , Female , Humans , Male , Middle Aged , Pneumococcal Vaccines , Retrospective Studies , Serogroup , Severity of Illness Index , Young Adult
12.
Vaccine ; 33(36): 4647-52, 2015 Aug 26.
Article in English | MEDLINE | ID: mdl-25980426

ABSTRACT

BACKGROUND: Concomitant administration of influenza and pneumococcal vaccines facilitates their uptake by older adults; however, data on immunogenicity and safety of concomitant administration of adjuvanted trivalent inactivated influenza vaccine (aIIV3) and 23-valent pneumococcal polysaccharide vaccine (PPSV23) have not been reported. METHODS: Subjects aged ≥65 years (N=224) were randomized 1:1:1:1 to receive MF59-aIIV3 alone, MF59-aIIV3+PPSV23 in contralateral arms, MF59-aIIV3+PPSV23 in the same arm or PPSV23 alone (Clinical Trial Number - NCT02225327). Hemagglutination inhibition assay and multiplex opsonophagocytic killing assay were used to compare immunogenicity after single or concomitant vaccination. RESULTS: All groups met immunogenicity criteria for the influenza vaccine in older adults with similar seroconversion rates and geometric mean fold-increases, irrespective of concomitant vaccinations and injection site. For each pneumococcal serotype, opsonic index (OI) increased markedly after the PPSV23 vaccination, irrespective of the concomitant influenza vaccine. All subjects showed an OI≥8 for serotypes 6B, 18C and 19A post-vaccination, with a suggestion that the ipsilateral concomitant vaccination might be associated with higher OIs for some antigens. Local and systemic adverse events were more common in subjects receiving PPSV23 compared to those receiving aIIV3 alone. CONCLUSIONS: No interference was observed with antibody responses to influenza or pneumococcal antigens when aIIV3 and PPSV23 were administered concomitantly.


Subject(s)
Adjuvants, Immunologic/adverse effects , Immunization Schedule , Influenza Vaccines/adverse effects , Pneumococcal Vaccines/adverse effects , Polysorbates/adverse effects , Squalene/adverse effects , Adjuvants, Immunologic/administration & dosage , Aged , Aged, 80 and over , Antibodies, Bacterial/blood , Antibodies, Viral/blood , Drug-Related Side Effects and Adverse Reactions/epidemiology , Drug-Related Side Effects and Adverse Reactions/pathology , Female , Hemagglutination Inhibition Tests , Humans , Influenza Vaccines/administration & dosage , Male , Opsonin Proteins/blood , Pneumococcal Vaccines/administration & dosage , Polysorbates/administration & dosage , Serum Bactericidal Antibody Assay , Squalene/administration & dosage , Treatment Outcome , Vaccines, Inactivated/administration & dosage , Vaccines, Inactivated/adverse effects
13.
Infect Chemother ; 47(4): 252-5, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26788409

ABSTRACT

Viral shedding lasted 31 and 19 days from symptom onset in two patients with east respiratory syndrome coronavirus (MERS-CoV) pneumonia, respectively. Environmental real-time RT-PCR was weakly positive for bed guardrail and monitors. Even after cleaning the monitors with 70% alcohol-based disinfectant, RT-PCR was still weakly positive, and converted to negative only after wiping with diluted sodium chlorite. Further studies are required to clarify the appropriate methods to clean environments during and after treatment of patients with MERS-CoV infection.

14.
Korean J Parasitol ; 52(4): 425-8, 2014 Aug.
Article in English | MEDLINE | ID: mdl-25246722

ABSTRACT

A 45-year-old-male who had underlying ulcerative colitis and presented with fever and dry cough. Initially, the patient was considered to have invasive aspergillosis due to a positive galactomannan assay. He was treated with amphotericin B followed by voriconazole. Nevertheless, the patient deteriorated clinically and radiographically. The lung biopsy revealed eosinophilic pneumonia, and ELISA for Toxocara antigen was positive, leading to a diagnosis of pulmonary toxocariasis. After a 10-day treatment course with albendazole and adjunctive steroids, the patient recovered completely without any sequelae. Pulmonary toxocariasis may be considered in patients with subacute or chronic pneumonia unresponsive to antibiotic agents, particularly in cases with eosinophilia.


Subject(s)
Colitis, Ulcerative/complications , Lung Diseases, Parasitic/diagnosis , Lung Diseases, Parasitic/pathology , Toxocara/isolation & purification , Toxocariasis/diagnosis , Toxocariasis/pathology , Albendazole/therapeutic use , Animals , Anthelmintics/therapeutic use , Anti-Inflammatory Agents/therapeutic use , Antigens, Helminth/analysis , Diagnosis, Differential , Enzyme-Linked Immunosorbent Assay , Humans , Lung/pathology , Male , Middle Aged , Pulmonary Aspergillosis/diagnosis , Pulmonary Aspergillosis/pathology , Steroids/therapeutic use , Treatment Outcome
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