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Find video protocols related to scientific articles indexed in Pubmed.
Effect of double blocking layers at TiO2/Sb2S3 and Sb2S3/spiro-MeOTAD interfaces on photovoltaic performance.
Faraday Discuss.
PUBLISHED: 11-20-2014
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The effect of double blocking layers on the Sb2S3-sensitized all solid state solar cell are investigated. Thin layers of ZrO2 (blocking layer 1, BL1) and ZnS (blocking layer 2, BL2) are introduced at the TiO2/Sb2S3 and Sb2S3/hole transporting material (HTM) interfaces. The presence of BL1 is found to improve the open-circuit voltage (Voc) from 457 mV to 618 mV, whereas BL2 improves mainly short-circuit current density (Jsc) from 11.1 mA cm(-2) to 14.0 mA cm(-2). Transient photovoltage confirms that the BL1 efficiently blocks charge recombination, responsible for the Voc enhancement, whereas the BL2 has little effect on suppression of charge recombination. Surface modification of Sb2S3 by BL2, on the other hand, leads to recovery of Sb2S3 from the surface oxidized Sb2O5, which affects the Jsc increment. The present results suggest that the TiO2/Sb2S3 interface is the main pathway for charge recombination rather than the Sb2S3/HTM interface. Double blocking layers enhanced the power conversion efficiency by 30%.
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A NATIONAL SURVEY OF OCCUPATIONAL RADIATION EXPOSURE AMONG DIAGNOSTIC RADIOLOGIC TECHNOLOGISTS IN SOUTH KOREA.
Radiat Prot Dosimetry
PUBLISHED: 11-09-2014
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The objective of this study was to investigate representative occupational characteristics and radiation exposure for South Korean radiologic technologists. The authors conducted a national survey by stratified sampling of South Korean administrative districts and types of medical facilities. A total of 585 technologists were surveyed, and survey data were linked with dosimetry data from the National Dose Registry. A total of 73 % of radiologic technologists sampled were male, 62 % were younger than age 40 and 86.5 % began employment after 1990. The most frequent practices among radiologic technologists were diagnostic routine X-ray followed by computed tomography (CT) and portable X-ray. Male workers were more frequently involved in CT, portable X-ray and interventional radiology whereas female workers carried out most mammography procedures. The average annual effective dose was 2.3 mSv for male and 1.3 mSv for female workers. The dose was significantly higher for workers in the provinces and those who had recently started work.
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General effect of low-dose tamsulosin (0.2?mg) as a first-line treatment for lower urinary tract symptoms associated with benign prostatic hyperplasia: a systematic review and meta-analysis.
Curr Med Res Opin
PUBLISHED: 10-29-2014
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Abstract Purpose: In Asian countries, low-dose tamsulosin (0.2?mg) is used widely but this dose has been less popular than 0.4?mg tamsulosin or other types of alpha blockers. The aim of this study was to investigate the efficacy and safety of low-dose tamsulosin by systematic review and meta-analysis. Methods: We conducted a meta-analysis of improvements of lower urinary tract symptoms using International Prostate Symptom Score (IPSS), maximal urinary flow rate (Qmax), post-voided residual volume (PVR), and quality of life (QOL). Relevant studies were found using MEDLINE, Embase, and the Cochrane library. Final inclusion was determined by randomized controlled trials (RCT) and performance of IPSS. Results: A total of fourteen studies were included, with a total sample size of 2147 subjects (1044 experimental and 1103 controls). Study durations ranged from 4 to 52 weeks. The mean change of IPSS improvement from baseline for tamsulosin was -7.18 (95% CI: -7.83, -6.54). The mean change of QOL improvement from baseline was -1.34 (95% CI: -1.46, -1.22). The overall Qmax improvement from baseline was 2.32?ml/sec (95% CI: 1.95, 2.70). The mean change of PVR improvement from baseline was -11.12?ml (95% CI: -17.61, -4.64). Regarding safety, four studies did not report any adverse events while others reported that adverse events were all tolerated. Conclusions: Although this study did not consider placebo effect and has high IPSS baseline scores, this study clarifies that low-dose tamsulosin has generally positive effect and safety in treatment of LUTS and could be a suitable option as an initial treatment, especially for patients with low body mass index, as is typical of Asian people.
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Paracrine effect of the bone morphogeneticprotein-2 at the experimental site on healing of the adjacent control site: a study in the rabbit calvarial defect model.
J Periodontal Implant Sci
PUBLISHED: 08-28-2014
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The aim of this study was to assess the possible paracrine effect of bone morphogeneticprotein-2 (BMP-2) at the experimental site on the adjacent control site for validating a rabbit calvarial defect model as a means of verifying the effect of BMP-2.
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The associations between serum zinc levels and metabolic syndrome in the Korean population: findings from the 2010 Korean National Health and Nutrition Examination Survey.
PLoS ONE
PUBLISHED: 08-25-2014
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The prevalence of metabolic syndrome has been increasing rapidly worldwide. The functions of zinc may have a potential association with metabolic syndrome, but such associations have not been investigated extensively. Therefore, we examined the relationship between serum zinc levels and metabolic syndrome or metabolic risk factors among South Korean adults ? 20 years of age. The analysis used data from the Korean National Health and Nutrition Examination Survey, a cross-sectional survey of Korean civilians, conducted from January to December 2010. A total of 1,926 participants were analyzed in this study. Serum zinc levels in men were negatively associated with elevated fasting glucose (adjusted odds ratio [aOR], 0.58; 95% confidence interval [CI], 0.36-0.93) and positively associated with elevated triglycerides (aOR, 1.47; 95% CI, 1.01-2.13). A difference in serum zinc levels was detected in women, depending on the number of metabolic syndrome components (p = 0.002). Furthermore, serum zinc levels showed a decreasing trend with increasing numbers of metabolic syndrome components in women with metabolic syndrome. These findings suggest that serum zinc levels might be associated with metabolic syndrome or metabolic risk factors. Further gender-specific studies are needed to evaluate the effect of dietary or supplemental zinc intake on metabolic syndrome.
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Temperature-dependent control of Staphylococcus aureus biofilms and virulence by thermoresponsive oligo(N-vinylcaprolactam).
Biotechnol. Bioeng.
PUBLISHED: 08-18-2014
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Bacterial biofilms are associated with persistent infections because they are highly tolerant of antimicrobial agents, and in the case of Staphylococcus aureus, which is a leading cause of nosocomial infections because of its resistance to diverse antibiotics, biofilm formation is a known mechanism of drug resistance. In the present study, we investigated the ability of thermoresponsive oligo (N-vinylcaprolactam) (OVCL) to control biofilm formation by and the virulence of S. aureus. One synthetic and four commercial OVCLs (
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Brain Metastases of Papillary Thyroid Carcinoma with Horner's Syndrome.
Brain Tumor Res Treat
PUBLISHED: 07-17-2014
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Papillary thyroid carcinoma (PTC) is the most common type of thyroid malignancy and has relatively favorable prognosis. Blood-borne metastases of PTC are very rare among the thyroid malignancies. Moreover a case of blood-borne central nervous system metastasized PTC with only unilateral Horner's syndrome, and without any abnormalities in laboratory or physical examinations has not been described before. A 53-year-old female patient had been managed in ophthalmologic clinic due to vague symptoms of right monocular blurred vision with eye dryness for 3 months, but showed no signs of improvement. So it was performed a magnetic resonance imaging and magnetic resonance angiography to evaluate the possibilities of cerebral lesion. And a left frontal mass was incidentally found, and the tumor turned out to be a PTC that had metastasized to brain, regional lymph node, cervical, thoracic spine, and lung. We describe a PTC with extraordinary initial symptoms that metastasized to an unusual site. We recommend that if a papillary thyroid tumor with unusual symptoms or at an advanced stage is found, further investigation should be performed for distant metastasis.
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Stilbenes reduce Staphylococcus aureus hemolysis, biofilm formation, and virulence.
Foodborne Pathog. Dis.
PUBLISHED: 07-09-2014
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Stilbenoids have a broad range of beneficial health effects. On the other hand, the emergence of antibiotic-resistant Staphylococcus aureus presents a worldwide problem that requires new antibiotics or nonantibiotic strategies. S. aureus produces ?-hemolysin (a pore-forming cytotoxin) that has been implicated in the pathogenesis of sepsis and pneumonia. Furthermore, the biofilms formed by S. aureus constitute a mechanism of antimicrobial resistance. In this study, we investigated the hemolytic and antibiofilm activities of 10 stilbene-related compounds against S. aureus. trans-Stilbene and resveratrol at 10??g/mL were found to markedly inhibit human blood hemolysis by S. aureus, and trans-stilbene also inhibited S. aureus biofilm formation without affecting its bacterial growth. Furthermore, trans-stilbene and resveratrol attenuated S. aureus virulence in vivo in the nematode Caenorhabditis elegans, which is normally killed by S. aureus. Transcriptional analysis showed that trans-stilbene repressed the ?-hemolysin hla gene and the intercellular adhesion locus (icaA and icaD) in S. aureus, and this finding was in line with observed reductions in virulence and biofilm formation. In addition, vitisin B, a stilbenoid tetramer, at 1??g/mL was observed to significantly inhibit human blood hemolysis by S. aureus.
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Agricultural pesticide usage and prioritization in South Korea.
J Agromedicine
PUBLISHED: 06-25-2014
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This study aims to review agricultural pesticide usage and trends and to identify hazardous pesticides for regulation, in terms of public health, in South Korea. The authors collected data on usage and trends of agricultural pesticides through agriculture-related databases. Criteria from the US Environmental Protection Agency classification for carcinogenicity, World Health Organization classification for acute toxicity, and European Union prioritization list for endocrine-disrupting chemicals were used for the hazard categorization of identified individual active ingredients. Pesticides to be prioritized among all pesticides used in South Korea between 2007 and 2011 were selected by taking into account the volume of usage, toxicity, and epidemiological evidence. Annual agricultural use of pesticides has increased rapidly from the 1970s to 1990s in South Korea, but has declined since 2001. The quantity of pesticides used in 2011 was reported as 19,131 tons, and was comprised of 34.7% insecticides, 28.0% fungicides, and 27.1% herbicides. The 50 pesticides with the greatest volume of usage accounted for 82.6% of the total volume of pesticides used between 2007 and 2011, with the most-used active ingredient being machine oil, followed by mancozeb and then paraquat. Organophosphates were the most used among the top 50 pesticides. A total of 24 pesticides were selected for recommendation of intensive regulation in South Korea. In conclusion, the authors described the usage and trends of overall agricultural pesticides, which would serve as a fundamental step forward in managing pesticide in terms of public health. Intensive efforts are required for the prevention of potential health effects from the 24 identified pesticides.
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Chemical chaperones reduce ionizing radiation-induced endoplasmic reticulum stress and cell death in IEC-6 cells.
Biochem. Biophys. Res. Commun.
PUBLISHED: 06-17-2014
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Radiotherapy, which is one of the most effective approaches to the treatment of various cancers, plays an important role in malignant cell eradication in the pelvic area and abdomen. However, it also generates some degree of intestinal injury. Apoptosis in the intestinal epithelium is the primary pathological factor that initiates radiation-induced intestinal injury, but the mechanism by which ionizing radiation (IR) induces apoptosis in the intestinal epithelium is not clearly understood. Recently, IR has been shown to induce endoplasmic reticulum (ER) stress, thereby activating the unfolded protein response (UPR) signaling pathway in intestinal epithelial cells. However, the consequences of the IR-induced activation of the UPR signaling pathway on radiosensitivity in intestinal epithelial cells remain to be determined. In this study, we investigated the role of ER stress responses in IR-induced intestinal epithelial cell death. We show that chemical ER stress inducers, such as tunicamycin or thapsigargin, enhanced IR-induced caspase 3 activation and DNA fragmentation in intestinal epithelial cells. Knockdown of Xbp1 or Atf6 with small interfering RNA inhibited IR-induced caspase 3 activation. Treatment with chemical chaperones prevented ER stress and subsequent apoptosis in IR-exposed intestinal epithelial cells. Our results suggest a pro-apoptotic role of ER stress in IR-exposed intestinal epithelial cells. Furthermore, inhibiting ER stress may be an effective strategy to prevent IR-induced intestinal injury.
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A preclinical rodent model of acute radiation-induced lung injury after ablative focal irradiation reflecting clinical stereotactic body radiotherapy.
Radiat. Res.
PUBLISHED: 06-17-2014
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In a previous study, we established an image-guided small-animal micro-irradiation system mimicking clinical stereotactic body radiotherapy (SBRT). The goal of this study was to develop a rodent model of acute phase lung injury after ablative irradiation. A radiation dose of 90 Gy was focally delivered to the left lung of C57BL/6 mice using a small animal stereotactic irradiator. At days 1, 3, 5, 7, 9, 11 and 14 after irradiation, the lungs were perfused with formalin for fixation and paraffin sections were stained with hematoxylin and eosin (H&E) and Masson's trichrome. At days 7 and 14 after irradiation, micro-computed tomography (CT) images of the lung were taken and lung functional measurements were performed with a flexiVent™ system. Gross morphological injury was evident 9 days after irradiation of normal lung tissues and dynamic sequential events occurring during the acute phase were validated by histopathological analysis. CT images of the mouse lungs indicated partial obstruction located in the peripheral area of the left lung. Significant alteration in inspiratory capacity and tissue damping were detected on day 14 after irradiation. An animal model of radiation-induced lung injury (RILI) in the acute phase reflecting clinical stereotactic body radiotherapy was established and validated with histopathological and functional analysis. This model enhances our understanding of the dynamic sequential events occurring in the acute phase of radiation-induced lung injury induced by ablative dose focal volume irradiation.
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Resveratrol and clofarabine induces a preferential apoptosis-activating effect on malignant mesothelioma cells by Mcl-1 down-regulation and caspase-3 activation.
BMB Rep
PUBLISHED: 06-14-2014
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We previously demonstrated that resveratrol and clofarabine elicited a marked cytotoxicity on malignant mesothelioma (MM) MSTO-211H cells but not on the corresponding normal mesothelial MeT-5A cells. Little is known of the possible molecules that could be used to predict preferential chemosensitivity on MSTO-211H cells. Resveratrol and clofarabine induced down-regulation of Mcl-1 protein level in MSTO-211H cells. Treatment of cells with cycloheximide in the presence of proteasome inhibitor MG132 suggested that Mcl-1 protein levels were regulated at the post-translational step. The siRNA-based knockdown of Mcl-1 in MSTO-211H cells triggered more growth-inhibiting and apoptosis-inducing effects with the resultant cleavages of procaspase-3 and its substrate PARP, increased caspase-3/7 activity, and increased percentage of apoptotic propensities. However, the majority of the observed changes were not shown in MeT-5A cells. Collectively, these studies indicate that the preferential activation of caspase cascade in malignant cells might have important applications as a therapeutic target for MM.
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The radiologic technologists' health study in South Korea: study design and baseline results.
Int Arch Occup Environ Health
PUBLISHED: 06-13-2014
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To describe the study design, methods, and baseline results of a prospective cohort of radiologic technologists which we have initiated in South Korea.
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Spin current generated by thermally driven ultrafast demagnetization.
Nat Commun
PUBLISHED: 06-06-2014
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Spin current is the key element for nanoscale spintronic devices. For ultrafast operation of such nano-devices, generation of spin current in picoseconds, a timescale that is difficult to achieve using electrical circuits, is highly desired. Here we show thermally driven ultrafast demagnetization of a perpendicular ferromagnet leads to spin accumulation in a normal metal and spin transfer torque in an in-plane ferromagnet. The data are well described by models of spin generation and transport based on differences and gradients of thermodynamic parameters. The temperature difference between electrons and magnons is the driving force for spin current generation by ultrafast demagnetization. On longer timescales, a few picoseconds following laser excitation, we also observe a small contribution to spin current by a temperature gradient and the spin-dependent Seebeck effect.
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Association between Dyslipidemia and the Prevalence of Colon Polyps Based on a Health Evaluation of Subjects at a Hospital.
Korean J Fam Med
PUBLISHED: 05-22-2014
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Colonic neoplasm is associated with western diet intake and physical inactivity. These life styles are also risk factors for dyslipidemia and metabolic syndrome. The aim of this study was to evaluate the association between dyslipidemia and the prevalence of colon polyps including colon adenoma as a precancerous lesion of colonic neoplasms.
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Overexpression of KAI1 Protein in Diabetic Skin Tissues.
Arch Plast Surg
PUBLISHED: 05-12-2014
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Patients with diabetes mellitus often have a difficult life, suffering from foot ulceration or amputation. Diabetes is characterized by chronic inflammation, and one of the features of inflammation is hypoxia. Recently, it has been reported that KAI1 is a hypoxia target gene. There is no published research on hypoxia-related KAI1 protein levels in human diabetic skin. Therefore, we have investigated the expression of KAI1 protein in diabetic skin tissue in vivo.
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Childhood leukemia mortality and farming exposure in South Korea: A national population-based birth cohort study.
Cancer Epidemiol
PUBLISHED: 04-30-2014
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The aim of this study was to evaluate the relationship between leukemia mortality and exposure to farming among children in South Korea.
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Anti-biofilm, anti-hemolysis, and anti-virulence activities of black pepper, cananga, myrrh oils, and nerolidol against Staphylococcus aureus.
Appl. Microbiol. Biotechnol.
PUBLISHED: 04-20-2014
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The long-term usage of antibiotics has resulted in the evolution of multidrug-resistant bacteria. Unlike antibiotics, anti-virulence approaches target bacterial virulence without affecting cell viability, which may be less prone to develop drug resistance. Staphylococcus aureus is a major human pathogen that produces diverse virulence factors, such as ?-toxin, which is hemolytic. Also, biofilm formation of S. aureus is one of the mechanisms of its drug resistance. In this study, anti-biofilm screening of 83 essential oils showed that black pepper, cananga, and myrrh oils and their common constituent cis-nerolidol at 0.01 % markedly inhibited S. aureus biofilm formation. Furthermore, the three essential oils and cis-nerolidol at below 0.005 % almost abolished the hemolytic activity of S. aureus. Transcriptional analyses showed that black pepper oil down-regulated the expressions of the ?-toxin gene (hla), the nuclease genes, and the regulatory genes. In addition, black pepper, cananga, and myrrh oils and cis-nerolidol attenuated S. aureus virulence in the nematode Caenorhabditis elegans. This study is one of the most extensive on anti-virulence screening using diverse essential oils and provides comprehensive data on the subject. This finding implies other beneficial effects of essential oils and suggests that black pepper, cananga, and myrrh oils have potential use as anti-virulence strategies against persistent S. aureus infections.
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Knockdown of Bcl-xL Enhances Growth-Inhibiting and Apoptosis-Inducing Effects of Resveratrol and Clofarabine in Malignant Mesothelioma H-2452 Cells.
J. Korean Med. Sci.
PUBLISHED: 04-15-2014
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Mcl-1 and Bcl-xL, key anti-apoptotic proteins of the Bcl-2 family, have attracted attention as important molecules in the cell survival and drug resistance. In this study, we investigated whether inhibition of Bcl-xL influences cell growth and apoptosis against simultaneous treatment of resveratrol and clofarabine in the human malignant mesothelioma H-2452 cells. Resveratrol and clofarabine decreased Mcl-1 protein levels but had little effect on Bcl-xL levels. In the presence of two compounds, any detectable change in the Mcl-1 mRNA levels was not observed in RT-PCR analysis, whereas pretreatment with the proteasome inhibitor MG132 led to its accumulation to levels far above basal levels. The knockdown of Bcl-xL inhibited cell proliferation with cell accumulation at G2/M phase and the appearance of sub-G0/G1 peak in DNA flow cytometric assay. The suppression of cell growth was accompanied by an increase in the caspase-3/7 activity with the resultant cleavages of procaspase-3 and its substrate poly (ADP-ribose) polymerase, and increased percentage of apoptotic propensities in annexin V binding assay. Collectively, our data represent that the efficacy of resveratrol and clofarabine for apoptosis induction was substantially enhanced by Bcl-xL-lowering strategy in which the simultaneous targeting of Mcl-1 and Bcl-xL could be a more effective strategy for treating malignant mesothelioma.
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Thermoresponsive oligomers reduce Escherichia coli O157:H7 biofouling and virulence.
Biofouling
PUBLISHED: 04-15-2014
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Thermoresponsive polymers have potential biomedical applications for drug delivery and tissue engineering. Here, two thermoresponsive oligomers were synthesized, viz. oligo(N-isopropylacrylamide) (ONIPAM) and oligo(N-vinylcaprolactam) (OVCL), and their anti-biofouling abilities investigated against enterohemorrhagic E. coli O157:H7, which produces Shiga-like toxins and forms biofilms. Biofilm formation (biofouling) is closely related to E. coli O157:H7 infection and constitutes a major mechanism of antimicrobial resistance. The synthetic OVCL (MW 679) and three commercial OVCLs (up to MW 54,000) at 30 ?g ml(-1) were found to inhibit biofouling by E. coli O157:H7 at 37 °C by more than 80% without adversely affecting bacterial growth. The anti-biofouling activity of ONIPAM was weaker than that of OVCL. However, at 25 °C, ONIPAM and OVCL did not affect E. coli O157:H7 biofouling. Transcriptional analysis showed that OVCL temperature-dependently downregulated curli genes in E. coli O157:H7, and this finding was in line with observed reductions in fimbriae production and biofouling. In addition, OVCL downregulated the Shiga-like toxin genes stx1 and stx2 in E. coli O157:H7 and attenuated its in vivo virulence in the nematode Caenorhabditis elegans. These results suggest that OVCL has potential use in antivirulence strategies against persistent E. coli O157:H7 infection.
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Suicide from carbon monoxide poisoning in South Korea: 2006-2012.
J Affect Disord
PUBLISHED: 04-10-2014
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Suicide from carbon monoxide poisoning by burning coal briquette or barbecue charcoal increased rapidly in some East Asian countries in the recent decade. The purpose of this study was to examine trends in suicides from carbon monoxide poisoning in South Korea and their epidemiologic characteristics.
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Regional changes in charcoal-burning suicide rates in East/Southeast Asia from 1995 to 2011: a time trend analysis.
PLoS Med.
PUBLISHED: 04-01-2014
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Suicides by carbon monoxide poisoning resulting from burning barbecue charcoal reached epidemic levels in Hong Kong and Taiwan within 5 y of the first reported cases in the early 2000s. The objectives of this analysis were to investigate (i) time trends and regional patterns of charcoal-burning suicide throughout East/Southeast Asia during the time period 1995-2011 and (ii) whether any rises in use of this method were associated with increases in overall suicide rates. Sex- and age-specific trends over time were also examined to identify the demographic groups showing the greatest increases in charcoal-burning suicide rates across different countries.
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Electrochemically active biofilm assisted synthesis of Ag@CeO? nanocomposites for antimicrobial activity, photocatalysis and photoelectrodes.
J Colloid Interface Sci
PUBLISHED: 03-28-2014
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Ag@CeO2 nanocomposites were synthesized by a biogenic and green approach using electrochemically active biofilms (EABs) as a reducing tool. The as-synthesized Ag@CeO2 nanocomposites were characterized and used in antimicrobial, visible light photocatalytic and photoelectrode studies. The Ag@CeO2 nanocomposites showed effective and efficient bactericidal activities and survival test against Escherichia coli O157:H7, and Pseudomonas aeruginosa. The as-synthesized Ag@CeO2 nanocomposites also exhibited enhanced visible light photocatalytic degradation of 4-nitrophenol and methylene blue than pure CeO2. A photocatalytic investigation showed that the Ag@CeO2 nanocomposites possessed excellent visible light photocatalytic activities compared to pure CeO2. Electrochemical impedance spectroscopy and photocurrent measurements showed that the as-synthesized Ag@CeO2 nanocomposites exhibited excellent and enhanced responses to visible light irradiation. These results suggest that the AgNPs anchored at CeO2 induced visible light photoactivity by decreasing the recombination of photogenerated electrons and holes, and extending the response of pure CeO2 to visible light. Overall, as-synthesized Ag@CeO2 nanocomposites are smart materials that can be used for a range of applications, such as antimicrobial activity, visible light photocatalysis and photoelectrode.
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Ionizing radiation activates PERK/eIF2?/ATF4 signaling via ER stress-independent pathway in human vascular endothelial cells.
Int. J. Radiat. Biol.
PUBLISHED: 03-19-2014
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Perturbations in protein folding induce endoplasmic reticulum (ER) stress, which elicits coordinated response, namely the unfolded protein response (UPR), to cope with the accumulation of misfolded proteins in ER. In this study, we characterized mechanisms underlying ionizing radiation (IR)-induced UPR signaling pathways.
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The impact of a celebrity's suicide on the introduction and establishment of a new method of suicide in South Korea.
Arch Suicide Res
PUBLISHED: 03-14-2014
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Unlike other East Asian countries, South Korea has until recently experienced relatively few charcoal burning suicides. We investigated trends in charcoal burning suicide immediately following the suicide by charcoal burning of the South Korean celebrity-Ahn Jae-Hwan-in September 2008. In the study, we compared the weekly number charcoal burning suicides 1 year before and after the celebrity's death. Before Ahn Jae-Hwan's suicide, charcoal burning accounted for <1% of suicides; his death was followed by an immediate and sustained increase in the use of this method-it accounted for nearly 5% of suicides (n = 772 suicides) in the subsequent 12 months. The demographic patterning (young male predominance) and location (inside cars) of the charcoal burning suicides further supported a copy-cat effect. Ahn Jae-Hwan's death appears to have triggered a rapid and sustained adoption of charcoal burning as a method of suicide in South Korea.
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High-efficiency perovskite solar cells based on the black polymorph of HC(NH2)2 PbI3.
Adv. Mater. Weinheim
PUBLISHED: 03-13-2014
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Perovskite solar cells with power conversion efficiencies exceeding 16% at AM 1.5 G one sun illumination are developed using the black polymorph of formamidnium lead iodide, HC(NH2)2 PbI3 . Compared with CH3 NH3 PbI3 , HC(NH2 )2 PbI3 extends its absoprtion to 840 nm and shows no phase transition between 296 and 423 K. Moreover, a solar cell based on HC(NH2 )2 PbI3 exhibits photostability and little I-V hysteresis.
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Angular and temperature dependence of current induced spin-orbit effective fields in Ta/CoFeB/MgO nanowires.
Sci Rep
PUBLISHED: 03-12-2014
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Current induced spin-orbit effective magnetic fields in metal/ferromagnet/oxide trilayers provide a new way to manipulate the magnetization, which is an alternative to the conventional current induced spin transfer torque arising from noncollinear magnetization. Ta/CoFeB/MgO structures are expected to be useful for non-volatile memories and logic devices due to its perpendicular anisotropy and large current induced spin-orbit effective fields. However many aspects such as the angular and temperature dependent phenomena of the effective fields are little understood. Here, we evaluate the angular and temperature dependence of the current-induced spin-orbit effective fields considering contributions from both the anomalous and planar Hall effects. The longitudinal and transverse components of effective fields are found to have strong angular dependence on the magnetization direction at 300?K. The transverse field decreases significantly with decreasing temperature, whereas the longitudinal field shows weaker temperature dependence. Our results reveal important features and provide an opportunity for a more comprehensive understanding of current induced spin-orbit effective fields.
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ZnO nanoparticles inhibit Pseudomonas aeruginosa biofilm formation and virulence factor production.
Microbiol. Res.
PUBLISHED: 03-10-2014
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The opportunistic pathogen Pseudomonas aeruginosa produces a variety of virulence factors, and biofilms of this bacterium are much more resistant to antibiotics than planktonic cells. Thirty-six metal ions have been investigated to identify antivirulence and antibiofilm metal ions. Zinc ions and ZnO nanoparticles were found to markedly inhibit biofilm formation and the production of pyocyanin, Pseudomonas quinolone signal (PQS), pyochelin, and hemolytic activity of P. aeruginosa without affecting the growth of planktonic cells. Transcriptome analyses showed that ZnO nanoparticles induce the zinc cation efflux pump czc operon and several important transcriptional regulators (porin gene opdT and type III repressor ptrA), but repress the pyocyanin-related phz operon, which explains observed phenotypic changes. A mutant study showed that the effects of ZnO nanoparticles on the control of pyocyanin production and biofilm formation require the czc regulator CzcR. In addition, ZnO nanoparticles markedly increased the cellular hydrophilicity of P. aeruginosa cells. Our results support that ZnO nanoparticles are potential antivirulence materials against recalcitrant P. aeruginosa infections and possibly other important pathogens.
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'Should I stay or should I go?' Bacterial attachment vs biofilm formation on surface-modified membranes.
Biofouling
PUBLISHED: 02-28-2014
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A number of techniques are used for testing the anti-biofouling activity of surfaces, yet the correlation between different results is often questionable. In this report, the correlation between initial bacterial deposition (fast tests, reported previously) and biofilm growth (much slower tests) was analyzed on a pristine and a surface-modified reverse osmosis membrane ESPA-1. The membrane was modified with grafted hydrophilic polymers bearing negatively charged, positively charged and zwitter-ionic moieties. Using three different bacterial strains it was found that there was no general correlation between the initial bacterial deposition rates and biofilm growth on surfaces, the reasons being different for each modified surface. For the negatively charged surface the slowest deposition due to the charge repulsion was eventually succeeded by the largest biofilm growth, probably due to secretion of extracellular polymeric substances (EPS) that mediated a strong attachment. For the positively charged surface, short-term charge attraction by quaternary amine groups led to the fastest deposition, but could be eventually overridden by their antimicrobial activity, resulting in non-consistent results where in some cases a lower biofilm formation rate was observed. The results indicate that initial deposition rates have to be used and interpreted with great care, when used for assessing the anti-biofouling activity of surfaces. However, for a weakly interacting 'low-fouling' zwitter-ionic surface, the positive correlation between initial cell deposition and biofilm growth, especially under flow, suggests that for this type of coating initial deposition tests may be fairly indicative of anti-biofouling potential.
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The multifaceted roles of the interspecies signalling molecule indole in Agrobacterium tumefaciens.
Environ. Microbiol.
PUBLISHED: 02-14-2014
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Bacteria utilize signal molecules to ensure their survival in environmental niches, and indole is an interspecies and interkingdom signalling molecule, which is widespread in the natural environment. In this study, we sought to identify novel roles of indole in soil-borne bacterium Agrobacterium tumefaciens. Agrobacterium tumefaciens was found not to synthesize indole and to degrade it rapidly. The addition of exogenous indole dose-dependently inhibited A.?tumefaciens growth and decreased its motility. Surprisingly, indole markedly increased A.?tumefaciens biofilm formation on polystyrene, glass and nylon membrane surfaces and enhanced its antibiotic tolerance. Transcriptional analysis showed that indole markedly up-regulated several biofilm-related (celA, cheA, exoR, phoB, flgE, fliR and motA), stress-related genes (clpB, dnaK, gsp, gyrB, marR and soxR) and efflux genes (emrA, norM, and Atu2551) in A.?tumefaciens, which partially explained the increased biofilm formation and antibiotic tolerance. In contrast, the plant auxin indole-3-acetic acid did not affect biofilm formation, antibiotic tolerance or gene expression. Interestingly, indole was found to exhibit several similarities with antibiotics, as it inhibited the growth of non-indole-producing bacteria, whereas these bacteria countered its effects by rapidly degrading indole, and by enhancing biofilm formation and antibiotic tolerance.
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Enhancement of the photovoltaic performance of CH?NH?PbI? perovskite solar cells through a dichlorobenzene-functionalized hole-transporting material.
Chemphyschem
PUBLISHED: 02-14-2014
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A dichlorobenzene-functionalized hole-transporting material (HTM) is developed for a CH3NH3PbI3-based perovskite solar cell. Notwithstanding the similarity of the frontier molecular orbital energy levels, optical properties, and hole mobility between the functionalized HTM [a polymer composed of 2'-butyloctyl-4,6-dibromo-3-fluorothieno[3,4-b]thiophene-2-carboxylate (TT-BO), 3',4'-dichlorobenzyl-4,6-dibromo-3-fluorothieno[3,4-b]thiophene-2-carboxylate (TT-DCB), and 2,6-bis(trimethyltin)-4,8-bis(2-ethylhexyloxy)benzo[1,2-b:4,5-b']dithiophene (BDT-EH), denoted PTB-DCB21] and the nonfunctionalized polymer [a polymer composed of thieno[3,4-b]thiophene (TT) and benzo[1,2-b:4,5-b']dithiophene (BDT), denoted PTB-BO], a higher power conversion efficiency for PTB-DCB21 (8.7%) than that for PTB-BO (7.4%) is achieved because of a higher photocurrent and voltage. The high efficiency is even obtained without including additives, such as lithium bis(trifluoromethanesulfonyl)imide and/or 4-tert-butylpyridine, that are commonly used to improve the conductivity of the HTM. Transient photocurrent-voltage studies show that the PTB-DCB21-based device exhibits faster electron transport and slower charge recombination; this might be related to better interfacial contact through intermolecular chemical interactions between the perovskite and the 3,4-dichlorobenzyl group in PTB-DCB21.
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Coumarins reduce biofilm formation and the virulence of Escherichia coli O157:H7.
Phytomedicine
PUBLISHED: 02-13-2014
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E. coli O157:H7 is the most common cause of hemorrhagic colitis, and no effective therapy exists for E. coli O157:H7 infection. Biofilm formation is closely related to E. coli O157:H7 infection and constitutes a mechanism of antimicrobial resistance. Hence, the antibiofilm or antivirulence approach provides an alternative to antibiotic strategies. Coumarin and its derivatives have a broad range of biological effects, and in this study, the antibiofilm activities of nine coumarins were investigated against E. coli O157:H7. Coumarin or umbelliferone at 50?g/ml was found to inhibit biofilm E. coli O157:H7 formation by more than 80% without affecting bacterial growth. Transcriptional analysis showed that coumarins repressed curli genes and motility genes in E. coli O157:H7, and these findings were in-line with observed reductions in fimbriae production, swarming motility, and biofilm formation. In addition, esculetin repressed Shiga-like toxin gene stx2 in E. coli O157:H7 and attenuated its virulence in vivo in the nematode Caenorhabditis elegans. These findings show that coumarins have potential use in antivirulence strategies against persistent E. coli O157:H7 infection.
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Evaluation of liquid and solid culture media for the recovery and enrichment of Burkholderia cenocepacia from distilled water.
J. Ind. Microbiol. Biotechnol.
PUBLISHED: 02-10-2014
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Burkholderia cepacia complex (BCC) presence has been the cause of recalls of both sterile and non-sterile pharmaceutical products since these opportunistic pathogens have been implicated to cause infections to susceptible individuals. BCC are ubiquitous in nature, but in pharmaceutical settings the most common source is contaminated water systems. Some strains of BCC, previously described as Pseudomonas cepacia, were not readily detected by standard culture methods. We have explored different strategies to recover and enrich Burkholderia cenocepacia previously cultured in distilled water for 40 days. Enrichment media of varied nutrient concentrations and composition were used, including modified Tryptic Soy Agar or Broth (TSA or TSB), Reasoner's 2nd Agar or Broth (R2A or R2AB), Brain-Heart Infusion Broth (BHIB), Mueller-Hinton Broth (MHB), and Ashdown's (ASH) medium. Of the various broth media tested, cell growth was significantly greater in TSB and R2AB than in BHIB, MHB, or ASH broth. TSB and R2AB were also compared for their recovery efficiency. Generally, there was no significant difference between the numbers of B. cenocepacia grown on 15 differently modified TSA and five modified R2A solid media. Overall, however, diluted TSA and TSB media, and R2A and R2AB showed better recovery efficiency than TSA and TSB for inocula containing small numbers of cells. All strains persisted in distilled water for 40 days. Broth media were more effective than solid media for recovery of B. cenocepacia from distilled water. These results may assist in improving detection assays with recovery and enrichment strategies to maximize recovery of these fastidious organisms.
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Exposure to Dichlorodiphenyltrichloroethane and the Risk of Breast Cancer: A Systematic Review and Meta-analysis.
Osong Public Health Res Perspect
PUBLISHED: 02-05-2014
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This study extended and updated a meta-analysis of the association between exposure to dichlorodiphenyltrichloroethane (DDT) and the risk of breast cancer.
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GeoChip 4: a functional gene-array-based high-throughput environmental technology for microbial community analysis.
Mol Ecol Resour
PUBLISHED: 02-02-2014
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Micro-organisms play critical roles in many important biogeochemical processes in the Earth's biosphere. However, understanding and characterizing the functional capacity of microbial communities are still difficult due to the extremely diverse and often uncultivable nature of most micro-organisms. In this study, we developed a new functional gene array, GeoChip 4, for analysing the functional diversity, composition, structure, metabolic potential/activity and dynamics of microbial communities. GeoChip 4 contained approximately 82 000 probes covering 141 995 coding sequences from 410 functional gene families related to microbial carbon (C), nitrogen (N), sulphur (S), and phosphorus (P) cycling, energy metabolism, antibiotic resistance, metal resistance/reduction, organic remediation, stress responses, bacteriophage and virulence. A total of 173 archaeal, 4138 bacterial, 404 eukaryotic and 252 viral strains were targeted, providing the ability to analyse targeted functional gene families of micro-organisms included in all four domains. Experimental assessment using different amounts of DNA suggested that as little as 500 ng environmental DNA was required for good hybridization, and the signal intensities detected were well correlated with the DNA amount used. GeoChip 4 was then applied to study the effect of long-term warming on soil microbial communities at a Central Oklahoma site, with results indicating that microbial communities respond to long-term warming by enriching carbon degradation, nutrient cycling (nitrogen and phosphorous) and stress response gene families. To the best of our knowledge, GeoChip 4 is the most comprehensive functional gene array for microbial community analysis.
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Protective effect of resveratrol derivatives on high-fat diet induced fatty liver by activating AMP-activated protein kinase.
Arch. Pharm. Res.
PUBLISHED: 01-26-2014
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Non-alcoholic fatty liver disease is associated with inhibited AMP-activated kinase (AMPK) and activation of sterol regulatory element binding protein 1 (SREBP-1). AMPK phosphorylation inhibits SREBP-1, a major transcription factor of de novo lipogenesis, by inhibiting the liver X receptor (LXR) or by direct phosphorylation. Resveratrol, a polyphenol, has regulatory effects on hepatic lipid metabolism as a potent AMPK activator. In this study, we evaluated the anti-steatogenic effects of resveratrol and its derivatives and identified the molecular mechanism in vitro and in vivo. Resveratrol and its derivatives decreased lipid accumulation by free fatty acids (FFA mixture; 0.5 mM, oleic acid:palmitic acid = 2: 1) in H4IIEC3 cells. Synthesized derivatives of resveratrol had lower cytotoxicity than the parental molecule with similar potency. SY-102 suppressed SREBP-1 maturation by T0901317, an LXR agonist, and decreased SRE luciferase activity and the mRNA levels of lipogenic genes. Inhibition of AMPK by pre-treatment with compound C completely blocked the effects of SY-102. To evaluate their efficacy in vivo, mice were fed a high-fat diet for 5 days, and resveratrol or SY-102 was administered orally for the last 2 days. Oral administration of the SY-102 increased AMPK phosphorylation, followed by reduced hepatic triglyceride accumulation to a similar extent as resveratrol. These data demonstrate that SY-102, a synthesized derivative of resveratrol, might provide a promising therapeutic effect against fatty liver disease.
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Resveratrol oligomers inhibit biofilm formation of Escherichia coli O157:H7 and Pseudomonas aeruginosa.
J. Nat. Prod.
PUBLISHED: 01-25-2014
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Biofilm formation is closely related to bacterial infection and is also a mechanism of antimicrobial resistance. Hence, the antibiofilm approach provides an alternative to an antibiotic strategy. In this study, the antibiofilm activities of resveratrol (1) and five of its oligomers, namely, ?-viniferin (2), suffruticosol A (3), suffruticosol B (4), vitisin A (5), and vitisin B (6), were investigated against enterohemorrhagic Escherichia coli O157:H7 and Pseudomonas aeruginosa PA14. Vitisin B (6), a stilbenoid tetramer, was found to inhibit biofilm formation by the two bacteria the most effectively and at 5 ?g/mL inhibited E. coli O157:H7 biofilm formation by more than 90%.
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Quantifying interface and bulk contributions to spin-orbit torque in magnetic bilayers.
Nat Commun
PUBLISHED: 01-10-2014
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Spin-orbit interaction-driven phenomena such as the spin Hall and Rashba effect in ferromagnetic/heavy metal bilayers enables efficient manipulation of the magnetization via electric current. However, the underlying mechanism for the spin-orbit interaction-driven phenomena remains unsettled. Here we develop a sensitive spin-orbit torque magnetometer based on the magneto-optic Kerr effect that measures the spin-orbit torque vectors for cobalt iron boron/platinum bilayers over a wide thickness range. We observe that the Slonczewski-like torque inversely scales with the ferromagnet thickness, and the field-like torque has a threshold effect that appears only when the ferromagnetic layer is thinner than 1?nm. Through a thickness-dependence study with an additional copper insertion layer at the interface, we conclude that the dominant mechanism for the spin-orbit interaction-driven phenomena in this system is the spin Hall effect. However, there is also a distinct interface contribution, which may be because of the Rashba effect.
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Ginkgolic acids and Ginkgo biloba extract inhibit Escherichia coli O157:H7 and Staphylococcus aureus biofilm formation.
Int. J. Food Microbiol.
PUBLISHED: 01-05-2014
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Infection by enterohemorrhagic Escherichia coli O157:H7 (EHEC) is a worldwide problem, and there is no effective therapy. Biofilm formation is closely related to EHEC infection and is also a mechanism of antimicrobial resistance. Antibiofilm screening of 560 purified phytochemicals against EHEC showed that ginkgolic acids C15:1 and C17:1 at 5?g/ml and Ginkgo biloba extract at 100?g/ml significantly inhibited EHEC biofilm formation on the surfaces of polystyrene and glass, and on nylon membranes. Importantly, at their working concentrations, ginkgolic acids and G. biloba extract did not affect bacterial growth. Transcriptional analyses showed that ginkgolic acid C15:1 repressed curli genes and prophage genes in EHEC, and these findings were in-line with reduced fimbriae production and biofilm reductions. Interestingly, ginkgolic acids and G. biloba extract did not inhibit the biofilm formation of a commensal E. coli K-12 strain. In addition, ginkgolic acids and G. biloba extract inhibited the biofilm formation of three Staphylococcus aureus strains. The findings of this study suggest that plant secondary metabolites represent an important resource for biofilm inhibitors.
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Mortality from and incidence of pesticide poisoning in South Korea: findings from National Death and Health Utilization Data between 2006 and 2010.
PLoS ONE
PUBLISHED: 01-01-2014
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Pesticide poisoning has been recognized as an important public health issue around the world. The objectives of this study were to report nationally representative figures on mortality from and the incidence of pesticide poisoning in South Korea and to describe their epidemiologic characteristics. We calculated the age-standardized rates of mortality from and the incidence of pesticide poisoning in South Korea by gender and region from 2006 through 2010 using registered death data obtained from Statistics Korea and national healthcare utilization data obtained from the National Health Insurance Review and Assessment Service of South Korea. During the study period of 2006 through 2010, a total of 16,161 deaths and 45,291 patients related to pesticide poisoning were identified, marking respective mortality and incidence rates of 5.35 and 15.37 per 100,000 population. Intentional self-poisoning was identified as the major cause of death due to pesticides (85.9%) and accounted for 20.8% of all recorded suicides. The rates of mortality due to and incidence of pesticide poisoning were higher in rural than in urban areas, and this rural-urban discrepancy was more pronounced for mortality than for incidence. Both the rate of mortality due to pesticide poisoning and its incidence rate increased with age and were higher among men than women. This study provides the magnitude and epidemiologic characteristics for mortality from and the incidence of pesticide poisoning at the national level, and strongly suggests the need for further efforts to prevent pesticide self-poisonings, especially in rural areas in South Korea.
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"cu-coo": can you recognize my stepparents?--A study of host-specific male call divergence in the common Cuckoo.
PLoS ONE
PUBLISHED: 01-01-2014
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The presence of multiple host-specific races in the common cuckoo Cuculus canorus has long been recognized as an evolutionary enigma but how this genetic divergence could be maintained is still equivocal. Some recent studies supported biparental genetic contribution in maintaining the host-races, implying the necessity that they should recognize and mate assortatively with those who belong to the same host-race. One potential mechanism to accomplish this is that males may produce distinctive calls according to host-specific lineages. In order to test this hypothesis, we carried out a comparative study for male cuckoo calls recorded from three distant populations, where two populations share a same host species while the other parasitizes a different host species. Populations with similar habitat structures, maintaining comparable distance interval (ca. 150 km) between neighboring ones, were selected so as to minimize any other causes of vocal differentiation except the pattern of host use. By comparing the vocal characteristics of male cuckoos at the level of individual as well as population, we found that individual males indeed produced different calls in terms of spectral and temporal features. However, these differences disappeared when we compared the calls at the population level according to host species and geographic location. In conclusion, it seems unlikely for the cuckoos to identify the stepparent of male cuckoos based solely on the vocal characteristics, although they may be able to use this cue for individual recognition. Future studies including detailed morphological and genetic comparisons will be worthwhile to further elucidate this issue.
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MMP9 processing of HSPB1 regulates tumor progression.
PLoS ONE
PUBLISHED: 01-01-2014
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Matrix metalloproteinases regulate pathophysiological events by processing matrix proteins and secreted proteins. Previously, we demonstrated that soluble heat shock protein B1 (HSPB1) is released primarily from endothelial cells (ECs) and regulates angiogenesis via direct interaction with vascular endothelial growth factor (VEGF). Here we report that MMP9 can cleave HSPB1 and release anti-angiogenic fragments, which play a key role in tumorprogression. We mapped the cleavage sites and explored their physiological relevance during these processing events. HSPB1 cleavage by MMP9 inhibited VEGF-induced ECs activation and the C-terminal HSPB1 fragment exhibited more interaction with VEGF than did full-length HSPB1. HSPB1 cleavage occurs during B16F10 lung progression in wild-type mice. Also, intact HSPB1 was more detected on tumor endothelium of MMP9 null mice than wild type mice. Finally, we confirmed that secretion of C-terminal HSPB1 fragment was significantly inhibited lung and liver tumor progression of B16F10 melanoma cells and lung tumor progression of CT26 colon carcinoma cells, compared to full-length HSPB1. These data suggest that in vivo MMP9-mediated processing of HSPB1 acts to regulate VEGF-induced ECs activation for tumor progression, releasing anti-angiogenic HSPB1 fragments. Moreover, these findings potentially explain an anti-target effect for the failure of MMP inhibitors in clinical trials, suggesting that MMP inhibitors may have pro-tumorigenic effects by reducing HSPB1 fragmentation.
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Comparison of CO-dependent H2 production with strong promoters in Thermococcus onnurineus NA1.
Appl. Microbiol. Biotechnol.
PUBLISHED: 10-11-2013
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To overproduce biotechnologically valuable products, the expression level of target genes has been modulated by using strong promoters. In a hyperthermophilic archaeon Thermococcus onnurineus NA1, two promoters, P TN0413 and P TN0157 , which drive expression of the genes encoding the S-layer protein and glutamate dehydrogenase were inserted in front of a gene cluster encoding a carbon monoxide dehydrogenase, a hydrogenase and a Na(+)/H(+) antiporter. Two promoters exhibited strong activity by increasing the transcription and translation levels of the gene cluster in the mutant strains by 2.5- to 49-folds and 1.4- to 3.3-folds, respectively, than the native promoter in the wild-type strain. While KS0413 with P TN0413 promoter exhibited 2.7 to 4.7 times higher transcript level than KS0157 with P TN0157 promoter, the levels of proteins were a little different between them. The biomass concentrations and H2 production rates of two mutants were 2- to 3-fold higher than those of the wild-type strain in a bioreactor where CO was supplied at a flow rate of 120 ml min(-1). Two mutants showed differential response to the higher CO flow rate, 240 ml min(-1), in terms of growth pattern and product formation, indicating two promoters were regulated by culture conditions. The results demonstrate that not only promoter strength but also product-forming conditions should be considered in promoter engineering.
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Inhibition of Snail1-DNA-PKcs protein-protein interface sensitizes cancer cells and inhibits tumor metastasis.
J. Biol. Chem.
PUBLISHED: 10-01-2013
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Our previous study suggested that the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) interacts with Snail1, which affects genomic instability, sensitivity to DNA-damaging agents, and migration of tumor cells by reciprocal regulation between DNA-PKcs and Snail1. Here, we further investigate that a peptide containing 7-amino acid sequences (amino acids 15-21) of Snail1 (KPNYSEL, SP) inhibits the endogenous interaction between DNA-PKcs and Snail1 through primary interaction with DNA-PKcs. SP restored the inhibited DNA-PKcs repair activity and downstream pathways. On the other hand, DNA-PKcs-mediated phosphorylation of Snail1 was inhibited by SP, which resulted in decreased Snail1 stability and Snail1 functions. However, these phenomena were only shown in p53 wild-type cells, not in p53-defective cells. From these results, it is suggested that interfering with the protein interaction between DNA-PKcs and Snail1 might be an effective strategy for sensitizing cancer cells and inhibiting tumor migration, especially in both Snail1-overexpressing and DNA-PKcs-overexpressing cancer cells with functional p53.
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Diverse plant extracts and trans-resveratrol inhibit biofilm formation and swarming of Escherichia coli O157:H7.
Biofouling
PUBLISHED: 09-25-2013
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Infection with enterohemorrhagic Escherichia coli O157:H7 (EHEC) is a worldwide problem. Of the 498 plant extracts screened against EHEC, 16 inhibited the formation of biofilm of EHEC by >85% without inhibiting the growth of planktonic cells, and 14 plant extracts reduced the swarming motility of EHEC. The most active extract, Carex dimorpholepis, decreased swimming and swarming motilities and curli formation. Transcriptional analyses showed that the extract of C. dimorpholepis repressed curli genes, various motility genes, and AI-2 quorum sensing genes, which was corroborated by reduction in the production of fimbria, motility, and biofilm by EHEC. Trans-resveratrol at 10??g?ml(-1) in the extract of C. dimorpholepis was found to be a new anti-biofilm compound against EHEC, but importantly, the extract of C. dimorpholepis and trans-resveratrol did not inhibit the fomation of biofilm in four commensal E. coli strains. Furthermore, the extract of C. dimorpholepis decreased the adhesion of EHEC cells to human epithelial cells without affecting the viability of these cells.
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Resveratrol contributes to chemosensitivity of malignant mesothelioma cells with activation of p53.
Food Chem. Toxicol.
PUBLISHED: 09-04-2013
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Resveratrol is a naturally occurring polyphenolic phytoalexin with chemopreventive properties. We previously reported a synergistic anti-proliferative effect of resveratrol and clofarabine against malignant mesothelioma (MM) cells. Here, we further investigated molecular mechanisms involved in the synergistic interaction of these compounds in MM MSTO-211H cells. Resveratrol, in combination with clofarabine, time-dependently induced a strong cytotoxic effect with the nuclear accumulation of phospho-p53 (p-p53) in MSTO-211H cells, but not in normal mesothelial MeT-5A cells. Combination treatment up-regulated the levels of p-p53, cleaved caspase-3, and cleaved PARP proteins. Gene silencing with p53-targeting siRNA attenuated the sensitivity of cells to the combined treatment of two compounds. Analyses of p53 DNA binding assay, p53 reporter gene assay, and RTP-CR toward p53-regulated genes, including Bax, PUMA, Noxa and p21, demonstrated that induced p-p53 is transcriptionally active. These results were further confirmed by the siRNA-mediated knockdown of p53 gene. Combination treatment significantly caused the accumulation of cells at G1 phase with the increases in the sub-G0/G1 peak, DNA ladder, nuclear fragmentation, and caspase-3/7 activity. Taken together, these results demonstrate that resveratrol and clofarabine synergistically elicit apoptotic signal via a p53-dependent pathway, and provide a scientific rationale for clinical evaluation of resveratrol as a promising chemopotentiator in MM.
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Activation of the leukotriene B4 receptor 2-reactive oxygen species (BLT2-ROS) cascade following detachment confers anoikis resistance in prostate cancer cells.
J. Biol. Chem.
PUBLISHED: 08-28-2013
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The majority of prostate cancer-related deaths are associated with advanced and metastatic malignancies. Although anoikis resistance has been recognized as one of the hallmarks of metastatic prostate malignancies, the molecular events that cause anoikis resistance are poorly understood. In this study, we found that the detachment of PC-3 prostate cancer cells caused a time-dependent increase in the expression level of the leukotriene B4 receptor-2 (BLT2) and that BLT2 played a critical role in establishing anoikis resistance in these cells. Blocking BLT2 with the pharmacological inhibitor LY255283 or with RNAi knockdown clearly abolished anoikis resistance and resulted in severe apoptotic death. Additionally, we demonstrated that the activation of NADPH oxidase (NOX) and subsequent generation of reactive oxygen species (ROS) were downstream of BLT2 signaling and led to the activation of NF-?B, thus establishing anoikis resistance during cell detachment. Furthermore, we observed that the ectopic expression of BLT2 in normal prostate PWR-1E cells rendered the cells resistant to anoikis and apparently diminished apoptotic cell death following detachment. Taken together, our results suggest that BLT2-NOX-ROS-NF-?B cascade induction during detachment confers a novel mechanism of anoikis resistance in prostate cancer cells and potentially contributes to prostate cancer progression.
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Acute Pesticide Poisoning among Children in South Korea: Findings from National Health Insurance Claims Data, 2006-2009.
J. Trop. Pediatr.
PUBLISHED: 08-12-2013
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Objectives: The aim of this study was to estimate the incidence of acute pesticide poisoning among children in South Korea and describe the related epidemiologic characteristics.Methods: We evaluated the age-standardized rates of incidence of pesticide poisoning among children in South Korea from 2006 through 2009 using National Health Insurance claims data.Results: A total of 1232 children aged 0-14 years were identified from the acute pesticide poisoning cases reported across South Korea during the study period. The annual average age-standardized rate of incidence from acute pesticide poisoning was 3.6 per 100 000. The majority of the cases were identified in the categories of the 1-4-year-old age-group (56.5%), outpatients (80.0%), single-day visit to a hospital (70.4%) and summer occurrence (43.3%).Conclusions: Acute pesticide poisoning is prevalent among children in South Korea; therefore, intervention efforts are needed to reduce the cases of pesticide poisoning among children.
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Experimental phasing using zinc and sulfur anomalous signals measured at the zinc absorption peak.
J. Microbiol.
PUBLISHED: 07-31-2013
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Iron is an essential transition metal required for bacterial growth and survival. Excess free iron can lead to the generation of reactive oxygen species that can cause severe damage to cellular functions. Cells have developed iron-sensing regulators to maintain iron homeostasis at the transcription level. The ferric uptake regulator (Fur) is an iron-responsive regulator that controls the expression of genes involved in iron homeostasis, bacterial virulence, stress resistance, and redox metabolism. Here, we report the expression, purification, crystallization, and phasing of the apo-form of Bacillus subtilis Fur (BsFur) in the absence of regulatory metal ions. Crystals were obtained by microbatch crystallization method at 295 K and diffraction data at a resolution of 2.6 Å was collected at the zinc peak wavelength (?=1.2823 Å). Experimental phasing identified the positions of one zinc atom and four sulfur atoms of cysteine residues coordinating the zinc atom, indicating that the data contained a meaningful anomalous scattering originating from the ordered zinc-coordinating sulfur atoms, in spite of the small anomalous signals of sulfur atoms at the examined wavelength.
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Inhibition of Pseudomonas aeruginosa and Escherichia coli O157:H7 Biofilm Formation by Plant Metabolite ?-Viniferin.
J. Agric. Food Chem.
PUBLISHED: 07-16-2013
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Pathogenic biofilms are associated with persistent infection due to their high resistances to diverse antibiotics. Pseudomonas aeruginosa infects plants, animals, and humans and is a major cause of nosocomial diseases in patients with cystic fibrosis. In the present study, the antibiofilm abilities of 522 plant extracts against P. aeruginosa PA14 were examined. Three Carex plant extracts at a concentration of 200 ?g/mL inhibited P. aeruginosa biofilm formation by >80% without affecting planktonic cell growth. In the most active extract of Carex pumila , resveratrol dimer ?-viniferin was one of the main antibiofilm compounds against P. aeruginosa. Interestingly, ?-viniferin at 10 ?g/mL inhibited biofilm formation of enterohemorrhagic Escherichia coli O157:H7 by 98%. Although Carex extracts and trans-resveratrol are known to possess antimicrobial activity, this study is the first to report that C. pumila extract and ?-viniferin have antibiofilm activity against P. aeruginosa and E. coli O157:H7.
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Chirality from interfacial spin-orbit coupling effects in magnetic bilayers.
Phys. Rev. Lett.
PUBLISHED: 07-12-2013
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As nanomagnetic devices scale to smaller sizes, spin-orbit coupling due to the broken structural inversion symmetry at interfaces becomes increasingly important. Here, we study interfacial spin-orbit coupling effects in magnetic bilayers using a simple Rashba model. The spin-orbit coupling introduces chirality into the behavior of the electrons and through them into the energetics of the magnetization. In the derived form of the magnetization dynamics, all of the contributions that are linear in the spin-orbit coupling follow from this chirality, considerably simplifying the analysis. For these systems, an important consequence is a correlation between the Dzyaloshinskii-Moriya interaction and the spin-orbit torque. We use this correlation to analyze recent experiments.
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Simultaneous Study of Exciton Diffusion/Dissociation and Charge Transport in a Donor-Acceptor Bilayer: Pentacene on a C60 -terminated Self-Assembled Monolayer.
Adv. Mater. Weinheim
PUBLISHED: 06-27-2013
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In-situ photoinduced threshold voltage measurement is a sensitive probe for exploring charge transport and exciton diffusion simultaneously, the main determinants of the power conversion efficiency in organic photovoltaic devices. The exciton diffusion length in a pentacene film deposited onto a C60 -terminated self-assembled monolayer is measured. The methodology and analysis presented here can be applied in the design and engineering of electron/donor acceptor interfaces for photovoltaic devices..
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Natural Course of Spontaneous Pneumothorax without Bullae or Blebs under High-Resolution Computed Tomography.
Thorac Cardiovasc Surg
PUBLISHED: 06-17-2013
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Background The cause of primary spontaneous pneumothorax (PSP) is known as rupture of some bullae or blebs.Objective The aim of this study is to clarify the natural course of spontaneous pneumothorax in the absence of bullae or blebs under high-resolution chest computed tomography (HRCT).Patients and Method From January 2006 to December 2010, 854 patients with PSP were enrolled in the study group. All subjects received a chest CT scan and were reviewed retrospectively.Result There were 56 PSP cases (6.5%) without bullae or blebs under HRCT. Treatments included oxygen therapy in 16 (28.5%) cases, arrow catheter insertion in 22 (39.2%) cases, closed thoracostomy in 17 (30.3%) cases, and 1 (1.7%) case received a video-assisted thoracoscopic surgery (VATS) operation. There were nine recurrent cases (16%). Of the nine cases, eight cases were treated with VATS operation. Several bullae or blebs were found in five of those nine operated cases, and there were severe inflammatory fibrotic changes on the apex of one of the nine operated cases.Conclusion Several bullae and blebs were revealed upon operation of PSP without previously detected bullae and blebs on HRCT. We cautiously recommend operating on PSP regardless of whether bullae and blebs are detected by HRCT as long as there are no contraindications to the operation.
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Sixfold enhancement of photocurrent by surface charge controlled high density quantum dot coating.
Chem. Commun. (Camb.)
PUBLISHED: 06-13-2013
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A wet-chemical method for increasing the number of quantum dots (QDs) per unit surface area of TiO2 was developed. High density QD surface coating was induced by a surface charge controlled SILAR method, which led to a sixfold increase in photocurrent density from 2.15 mA cm(-2) to 15.03 mA cm(-2) in a QD-sensitized solar cell based on a Hg-doped PbS sensitized 2.4 ?m-thick TiO2 film.
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Suicidal ideation and occupational pesticide exposure among male farmers.
Environ. Res.
PUBLISHED: 05-16-2013
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The occupation of farming has been reported to be associated with a high suicide rate, and suicidal ideation is an important risk factor for suicide. The objective of this study was to explore the association between occupational pesticide exposure or poisoning history and suicidal ideation among male farmers in South Korea.
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High efficiency solid-state sensitized solar cell-based on submicrometer rutile TiO2 nanorod and CH3NH3PbI3 perovskite sensitizer.
Nano Lett.
PUBLISHED: 05-16-2013
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We report a highly efficient solar cell based on a submicrometer (~0.6 ?m) rutile TiO2 nanorod sensitized with CH3NH3PbI3 perovskite nanodots. Rutile nanorods were grown hydrothermally and their lengths were varied through the control of the reaction time. Infiltration of spiro-MeOTAD hole transport material into the perovskite-sensitized nanorod films demonstrated photocurrent density of 15.6 mA/cm(2), voltage of 955 mV, and fill factor of 0.63, leading to a power conversion efficiency (PCE) of 9.4% under the simulated AM 1.5G one sun illumination. Photovoltaic performance was significantly dependent on the length of the nanorods, where both photocurrent and voltage decreased with increasing nanorod lengths. A continuous drop of voltage with increasing nanorod length correlated with charge generation efficiency rather than recombination kinetics with impedance spectroscopic characterization displaying similar recombination regardless of the nanorod length.
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Anti-biofilm activities of quercetin and tannic acid against Staphylococcus aureus.
Biofouling
PUBLISHED: 05-13-2013
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Staphylococcus aureus is a leading cause of nosocomial infections because of its resistance to diverse antibiotics. The formation of a biofilm is one of the mechanisms of drug resistance in S. aureus. The anti-biofilm abilities of 498 plant extracts against S. aureus were examined. Seventy-two plant extracts belonging to 59 genera and 38 families were found to significantly inhibit the formation of biofilms of S. aureus without affecting the growth of planktonic cells. The most active extract, from Alnus japonica, inhibited the formation of biofilms by three S. aureus strains by >70% at 20 ?g ml(-1). Transcriptional analyses showed that extract of A. japonica repressed the intercellular adhesion genes icaA and icaD most markedly. Quercetin and tannic acid are major anti-biofilm compounds in the extract of A. japonica. Additionally, the extract of A. japonica and its component compound quercetin, reduced hemolysis by S. aureus. This phenomenon was not observed in the treatment with tannic acid. This study suggests that various plant extracts, such as quercetin and tannic acid, could be used to inhibit the formation of recalcitrant biofilms of S. aureus.
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Characterization of gibberellin biosynthetic gene cluster from Fusarium proliferatum.
J. Microbiol. Biotechnol.
PUBLISHED: 05-08-2013
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Gibberellins (GAs) are a group of phytohormones that control many developmental processes in higher plants. We report the cloning and expression pattern of gibberellin biosynthesis genes from a new GA-producing fungus, Fusarium proliferatum (strain KGL0401). These genes sequences are deposited in the National Center for Biotechnology Information (NCBI) under accession numbers EF119831, EF119832, DQ313173, DQ313174, DQ313175, DQ313176, and DQ313177. The expression level of these genes was maximal at a 0.5 M : 0.17 M carbon : nitrogen ratio, and minimal at a 0.25 M : 0.47 M carbon : nitrogen ratio.
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Spin wave nonreciprocity for logic device applications.
Sci Rep
PUBLISHED: 05-01-2013
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The utilization of spin waves as eigenmodes of the magnetization dynamics for information processing and communication has been widely explored recently due to its high operational speed with low power consumption and possible applications for quantum computations. Previous proposals of spin wave Mach-Zehnder devices were based on the spin wave phase, a delicate entity which can be easily disrupted. Here, we propose a complete logic system based on the spin wave amplitude utilizing the nonreciprocal spin wave behavior excited by microstrip antennas. The experimental data reveal that the nonreciprocity of magnetostatic surface spin wave can be tuned by the bias magnetic field. Furthermore, engineering of the device structure could result in a high nonreciprocity factor for spin wave logic applications.
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Assessment of pain and anxiety following surgical placement of dental implants.
Int J Oral Maxillofac Implants
PUBLISHED: 03-26-2013
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To investigate the change in 89 patients pain and anxiety following implant surgery and to evaluate the correlation among anxiety, pain, and influencing factors.
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Interleukin-18 gene polymorphisms and rheumatoid arthritis: a meta-analysis.
Gene
PUBLISHED: 03-17-2013
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Interleukin-18 (IL-18) is a member of the IL-1 superfamily that enhances both innate and acquired immune responses. IL-18 is highly expressed in sera, synovial fluids and synovial tissues of patients with RA, and these IL-18 levels are correlated with RA disease activity, indicating an important role of IL-18 in the pathogenesis of RA. Several studies have examined the association of IL-18 gene polymorphisms with RA, but these studies have shown inconclusive and controversial results. To verify the association between IL-18 gene polymorphism and susceptibility to RA, we conducted a meta-analysis of all relevant reports cited in MEDLINE/PubMed before October 2012. A meta-analysis on the association between the IL-18 rs1946518 SNP and RA was performed for 2944 patients with RA and 2377 controls from 7 published studies and a meta-analysis on the association between the IL-18 rs187238 SNP and RA was performed for 1319 patients with RA and 1211 controls from 5 published studies. In addition, 2 studies involving 1873 RA patients and 1092 controls were considered in the meta-analysis of the association between the IL-18 rs360722 SNP and RA. No significant association was found between two IL-18 SNPs (rs1946518 and rs187238) and RA susceptibility in all subjects. In subgroup analysis stratified by ethnicity, there was still no significant association between these two IL-18 SNPs and RA susceptibility. However, the frequency of the T allele at rs360722 was found to be significantly lower in patients with RA compared with controls, although this finding was based on only 2 studies. The results of our meta-analysis suggest that IL-18 rs360722 SNP is only associated with RA susceptibility. However, due to only two studies included in our meta-analysis, large-scale well designed studies should be considered in future studies to confirm the exact role of IL-18 rs360722 SNP in RA susceptibility.
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Association between the polymorphisms of glutathione S-transferase genes and rheumatoid arthritis: a meta-analysis.
Gene
PUBLISHED: 03-07-2013
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The glutathione S-transferases (GSTs) are a family of phase II xenobiotic metabolizing enzymes known to be involved in the detoxification and elimination of reactive oxygen species (ROS), thus defending tissues against oxidative stress. Recently, several studies have examined the potential contributions of GSTM1 and GSTT1 gene polymorphisms toward susceptibility to rheumatoid arthritis (RA), but these studies have produced diverse results. To verify the association between GSTM1 and GSTT1 gene polymorphisms and susceptibility to RA, we conducted a meta-analysis of all relevant reports cited in MEDLINE/PubMed before April 2012. A meta-analysis on the association between the GSTM1 polymorphism and RA was performed for 4636 patients with RA and 3916 controls from 8 published studies. In addition, a total of 5 studies involving 3174 RA patients and 2958 controls were considered in the meta-analysis of the association between the GSTT1 polymorphism and RA. No significant association was found between the GSTM1 null genotype and RA susceptibility in all subjects; however, a significant increased risk was found in East Asians. The GSTT1 null genotype was not associated with susceptibility to RA in any study subject. No apparent effect of smoking was found in stratified analysis. The results of our meta-analysis indicated that the GSTM1 null genotype is significantly associated with RA in East Asians alone, indicating that GSTM1 is another non-human leukocyte antigen (non-HLA) susceptibility gene for RA in East Asian populations.
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In-house zinc SAD phasing at Cu K? edge.
Mol. Cells
PUBLISHED: 02-28-2013
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De novo zinc single-wavelength anomalous dispersion (Zn-SAD) phasing has been demonstrated with the 1.9 Å resolution data of glucose isomerase and 2.6 Å resolution data of Staphylococcus aureus Fur (SaFur) collected using in-house Cu K? X-ray source. The successful in-house Zn-SAD phasing of glucose isomerase, based on the anomalous signals of both zinc ions introduced to crystals by soaking and native sulfur atoms, drove us to determine the structure of SaFur, a zinc-containing transcription factor, by Zn-SAD phasing using in-house X-ray source. The abundance of zinc-containing proteins in nature, the easy zinc derivatization of the protein surface, no need of synchrotron access, and the successful experimental phasing with the modest 2.6 Å resolution SAD data indicate that inhouse Zn-SAD phasing can be widely applicable to structure determination.
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Production of Cyr61 protein is modulated by extracellular acidification and PI3K/Akt signaling in prostate carcinoma PC-3 cells.
Food Chem. Toxicol.
PUBLISHED: 02-15-2013
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High expression of Cyr61, an extracellular cysteine-rich heparin-binding protein, has been associated with a malignant cell phenotype and poor outcome in prostate cancers. Although Cyr61 was found by us to be overproduced in androgen-independent PC-3 cells treated with N-acetylcysteine (NAC), its significance is still unclear. We therefore aimed to determine how and why Cyr61 protein is overexpressed in NAC-treated cells. Here, we found that Cyr61 protein level markedly increased in cells treated with NAC at high cell seeding density. Silencing of Cyr61 by siRNA induced enhanced activity of caspase-3/7, upregulation of the proapototic Bok, BimL and BimS, cleavage of apoptosis hallmarkers such as Bax, PARP and caspase-3, and downregulation of antiapoptotic Bcl2, Bcl-xL and Mcl-1 proteins. NAC treatment caused a reduction of extracellular medium pH to acidic and an increase in Akt phosphorylation, after which the replacement with NAC-free medium returned them to control levels within 24h. Acid stimulation increased the levels of Cyr61 and p-Akt proteins, whereas it suppressed the induction of proapoptotic and antiapoptotic proteins. Overall, our data indicate that PC-3 cells overproduce Cyr61 protein via activation of the PI3K/Akt signaling as a part of the survival mechanisms under the conditions causing extracellular acidity and further cytotoxicity.
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Spatial and temporal expression, and statin responsiveness of galectin-1 and galectin-3 in murine atherosclerosis.
Korean Circ J
PUBLISHED: 02-14-2013
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Existing data on the spatiotemporal expression patterns of a variety of galectins in murine atherosclerosis are limited. We investigated the expression levels of galectins, and their in vivo spatiotemporal expression patterns and statin responsiveness in the inflamed atherosclerotic plaques of apolipoprotein E (apoE)(-/-) mice.
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Work-related risk factors by severity for acute pesticide poisoning among male farmers in South Korea.
Int J Environ Res Public Health
PUBLISHED: 02-08-2013
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The objective of this study was to explore work-related risk factors of acute occupational pesticide poisoning among male farmers according to the severity of the poisoning. A nationwide sampling survey of male farmers was conducted in South Korea in 2011. A total of 1,958 male farmers were interviewed. Severity of occupational pesticide poisoning in 2010 was evaluated according to symptoms, types of treatment, and number of pesticide poisoning incidents per individual. A multinomial logistic regression model was used to estimate the odds ratio with 95% confidence intervals for risk factors of acute occupational pesticide poisoning. We found that the risk of acute occupational pesticide poisoning increased with lifetime days of pesticide application (OR = 1.74; 95% CI = 1.32-2.29), working a farm of three or more acres in size (OR = 1.49), not wearing personal protective equipment such as gloves (OR = 1.29) or masks (OR = 1.39). Those who engaged in inappropriate work behaviors such as not following pesticide label instructions (OR = 1.61), applying the pesticide in full sun (OR = 1.48), and applying the pesticide upwind (OR = 1.54) had a significantly increased risk of pesticide poisoning. There was no significant risk difference by type of farming. In addition, the magnitude of these risk factors did not differ significantly by severity of acute pesticide poisoning. In fact, our findings suggest that work-related risk factors contributed to the development of acute occupational pesticide poisoning without relation to its severity. Therefore, prevention strategies for reducing occupational pesticide poisoning, regardless of severity, should be recommended to all types of farming and the level of poisoning severity.
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Depressive symptoms and severity of acute occupational pesticide poisoning among male farmers.
Occup Environ Med
PUBLISHED: 02-06-2013
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Limited evidence suggests the association between severity of acute occupational pesticide poisoning and depressive symptoms in farmers. The aim of this study was to investigate the association between occupational pesticide exposure and depressive symptoms among male farmers in South Korea.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.