Flexible NO2 gas sensor using multilayer graphene films by chemical vapor deposition

We report a highly sensitive NO2 gas sensor based on multi-layer graphene (MLG) films synthesized by a chemical vapor deposition method on a microheater-embedded flexible substrate. The MLG could detect low-concentration NO2 even at sub-ppm (<200 ppb) levels. It also exhibited a high resistance change of ~6% when it was exposed to 1 ppm NO2 gas at room temperature for 1 min. The exceptionally high sensitivity could be attributed to the large number of NO2 molecule adsorption sites on the MLG due to its a large surface area and various defect-sites, and to the high mobility of carriers transferred between the MLG films and the adsorbed gas molecules. Although desorption of the NO2 molecules was slow, it could be enhanced by an additional annealing process using an embedded Au microheater. The outstanding mechanical flexibility of the graphene film ensures the stable sensing response of the device under extreme bending stress. Our large-scale and easily reproducible MLG films can provide a proof-of-concept for future flexible NO2 gas sensor devices.clos

Bronchospasm and Anaphylactic Shock Following Lidocaine Aerosol Inhalation in a Patient with Butane Inhalation Lung Injury

Allergic reactions to local anesthetics are very rare and represent <1% of all adverse local anesthetics reactions. A 54-year-old man was admitted to the hospital in the winter because of shortness of breath. The patient reportedly had an inhalation lung injury due to butane gas fuel. On the fifth day, he developed an asthmatic attack and anaphylactic shock immediately after lidocaine aerosol administration to prepare for bronchoscopy to confirm an acute inhalational lung injury diagnosis. Cardiopulmonary resuscitation was performed immediately after respiratory arrest, and the patient was admitted to the intensive care unit intubated and on a ventilator. He was extubated safely on the third post-cardiopulmonary resuscitation day. These observations suggest that aerosol lidocaine anesthesia may cause airway narrowing and anaphylactic shock. Practitioners should be aware of this potential complication. We report on this case with a brief review of the literature

Post-traumatic Back Pain Revealed as Tuberculous Spondylitis -A Case Report-

Tuberculous spondylitis is a very rare disease, but it can result in bone destruction, kyphotic deformity, spinal instability, and neurologic complications unless early diagnosis and proper management are done. Because the most common symptom of tuberculous spondylitis is back pain, it can often be misdiagnosed. Atypical tuberculous spondylitis can be presented as a metastatic cancer or a primary vertebral tumor. We must make a differential diagnosis through adequate biopsy. A 30-year-old man visited our clinic due to back and chest pain after a recent traffic accident. About 1 year ago, he had successfully recovered from tuberculous pleurisy after taking anti-tuberculosis medication. We performed epidural and intercostal blocks but the pain was not relieved. For the further evaluation, several imaging and laboratory tests were done. Finally, we confirmed tuberculous spondylitis diagnosis with the biopsy results

Multivariate analysis of prognostic factors in patients with pulmonary actinomycosis

BACKGROUND: There have been few studies of pulmonary actinomycosis, which is an uncommon anaerobic infection. Consequently, the optimal therapeutic regimen, appropriate duration of treatment, long-term prognosis, and factors predicting prognosis are not well established. METHODS: We retrospectively reviewed the medical records of histopathologically confirmed cases of pulmonary actinomycosis seen between November 2003 and December 2012. RESULTS: The study included 68 patients with a mean age of 58.4 ± 11.6 years. Of the 68, initial surgery was performed in 15 patients (22.1%), while the remaining 53 (77.9%) received antibiotic therapy initially. In the initial antibiotic group, 45/53 (84.9%) were cured without relapse (median antibiotic duration 5.3 months). 5/53 (9.4%) patients were refractory medically (median antibiotic duration 9.7 months), and 3/53 (5.7%) experienced a recurrence (median time to relapse 35.3 months). In the initial surgery group, 14/15 (93.3%) were cured and treatment failure occurred in one (6.7%). In the multivariate analysis, the absence of an antibiotic response at 1 month was the only independent factor associated with a poor treatment outcome, with an adjusted odds ratio of 49.2 (95% CI, 3.34–724.30). There was no significant difference in treatment outcome based on the size of the parenchymal lesion, comorbidities, whether intravenous antibiotics were used, antibiotic therapy duration, or whether the initial treatment was surgical. CONCLUSIONS: Antibiotic treatment with or without surgery was effective for treatment of pulmonary actinomycosis. Nevertheless, treatment failure or recurrence occurred in a considerable proportion of patients, especially those resistant to the initial antibiotic treatment

Clinical Features and Outcomes of Idiopathic Pulmonary Alveolar Proteinosis in Korean Population

Idiopathic pulmonary alveolar proteinosis (PAP) is a rare disorder in which lipoproteinaceous material accumulates within alveoli. There were few reports on Asian populations with idiopathic PAP. We retrospectively reviewed 38 patients with idiopathic PAP in Korea. We assessed clinical features, therapeutic efficacy and outcomes of whole lung lavage in patients with idiopathic PAP. The mean age at diagnosis was 52 yr. Eighty six percent of patients were symptomatic at diagnosis. Dyspnea and cough were the most common symptoms. Crackles were the most common physical examination finding. On pulmonary function test, a mild restrictive ventilatory defect was common, with a predicted mean forced vital capacity (FVC) of 77% and forced expiratory volume in one second (FEV1) of 84.6%. Diffusing capacity was disproportionately reduced at 67.7%. Arterial blood gas analysis revealed hypoxemia with a decreased PaO2 of 69.0 mmHg and an increased D(A-a)O2 of 34.2 mmHg. After whole lung lavage, PaO2, D(A-a)O2 and DLCO were significantly improved, but FVC and total lung capacity (TLC) were not different. This is the first multicenter study to analyze 38 Korean patients with idiopathic PAP. The clinical features and pulmonary parameters of Korean patients with idiopathic PAP are consistent with reports in other published studies. Whole lung lavage appears to be the most effective form of treatment

Expression and Regulation of Latent TGF-β Binding Protein-1 Transcripts and Their Splice Variants in Human Glomerular Endothelial Cells

Latent transforming growth factor (TGF)-β-binding protein (LTBP) is required for the assembly, secretion, matrix association, and activation of latent TGF-β complex. To elucidate the cell specific expression of the genes of LTBP-1 and their splice variants and the factors that regulate the gene expression, we cultured primary human glomerular endothelial cells (HGEC) under different conditions. Basal expression of LTBP-1 mRNA was suppressed in HGEC compared to WI-38 human embryonic lung fibroblasts. High glucose, H2O2, and TGF-β1 upregulated and vascular endothelial growth factor (VEGF) further downregulated LTBP-1 mRNA in HGEC. RT-PCR with a primer set for LTBP-1S produced many clones but no clone was gained with a primer set for LTBP-1L. Of 12 clones selected randomly, Sca I mapping and DNA sequencing revealed that only one was LTBP-1S and all the others were LTBP-1SΔ53. TGF-β1, but not high glucose, H2O2 or VEGF, tended to increase LTBP-1SΔ53 mRNA. In conclusion, HGEC express LTBP-1 mRNA which is suppressed at basal state but upregulated by high glucose, H2O2, and TGF-β1 and downregulated by VEGF. Major splice variant of LTBP-1 in HGEC was LTBP-1SΔ53. Modification of LTBP-1SΔ53 gene in HGEC may abrogate fibrotic action of TGF-β1 but this requires confirmation

Potential Association of DCBLD2 Polymorphisms with Fall Rates of FEV1 by Aspirin Provocation in Korean Asthmatics

Aspirin exacerbated respiratory disease (AERD) is a clinical syndrome characterized by chronic rhinosinusitis with nasal polyposis and aspirin hypersensitivity. The aspirin-induced bronchospasm is mediated by mast cell and eosinophilic inflammation. Recently, it has been reported that the expression of discoidin, CUB and LCCL domain-containing protein 2 (DCBLD2) is up-regulated in lung cancers and is regulated by transcription factor AP-2 alpha (TFAP2A), a component of activator protein-2 (AP-2) that is known to regulate IL-8 production in human lung fibroblasts and epithelial cells. To investigate the associations between AERD and DCBLD2 polymorphisms, 12 common variants were genotyped in 163 AERD subjects and 429 aspirin tolerant asthma (ATA) controls. Among these variants, seven SNPs (rs1371687, rs7615856, rs828621, rs828618, rs828616, rs1062196, and rs8833) and one haplotype (DCBLD2-ht1) show associations with susceptibility to AERD. In further analysis, this study reveals significant associations between the SNPs or haplotypes and the percentage of forced expiratory volume in one second (FEV1) decline following aspirin challenge using multiple linear regression analysis. Furthermore, a non-synonymous SNP rs16840208 (Asp723Asn) shows a strong association with FEV1 decline in AERD patients. Although further studies for the non-synonymous Asp723Asn variation are needed, our findings suggest that DCBLD2 could be related to FEV1-related phenotypes in asthmatics