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1.
Nanomaterials (Basel) ; 12(17)2022 Aug 27.
Article in English | MEDLINE | ID: mdl-36080003

ABSTRACT

Chemical warfare agents (CWAs) have inflicted monumental damage to human lives from World War I to modern warfare in the form of armed conflict, terrorist attacks, and civil wars. Is it possible to detect the CWAs early and prevent the loss of human lives? To answer this research question, we synthesized hybrid composite materials to sense CWAs using hydrothermal and thermal reduction processes. The synthesized hybrid composite materials were evaluated with quartz crystal microbalance (QCM) and surface acoustic wave (SAW) sensors as detectors. The main findings from this study are: (1) For a low dimethyl methyl phosphonate (DMMP) concentration of 25 ppm, manganese dioxide nitrogen-doped graphene oxide (NGO@MnO2) and NGO@MnO2/Polypyrrole (PPy) showed the sensitivities of 7 and 51 Hz for the QCM sensor and 146 and 98 Hz for the SAW sensor. (2) NGO@MnO2 and NGO@MnO2/PPy showed sensitivities of more than 50-fold in the QCM sensor and 100-fold in the SAW sensor between DMMP and potential interferences. (3) NGO@MnO2 and NGO@MnO2/PPy showed coefficients of determination (R2) of 0.992 and 0.975 for the QCM sensor and 0.979 and 0.989 for the SAW sensor. (4) NGO@MnO2 and NGO@MnO2/PPy showed repeatability of 7.00 ± 0.55 and 47.29 ± 2.69 Hz in the QCM sensor and 656.37 ± 73.96 and 665.83 ± 77.50 Hz in the SAW sensor. Based on these unique findings, we propose NGO@MnO2 and NGO@MnO2/PPy as potential candidate materials that could be used to detect CWAs.

2.
J Med Entomol ; 57(5): 1560-1566, 2020 09 07.
Article in English | MEDLINE | ID: mdl-32300813

ABSTRACT

For the indoor and outdoor pest controls, various types of insecticide formulations are available including aerosols, sprays, electric vaporizers, mosquito coils, and traps. In the present study, the insecticidal activity of aerosols, the most commonly used formulation of household insecticides for mosquito control, against Aedes albopictus (Skuse) was assessed using seven commercial products and some attributes which can affect the efficacy of aerosol were investigated as well. The products had difference in their chemical composition of active ingredients, propellant/liquid phase ratios, solvent types, and nozzle orifice sizes, and these characteristics seem to affect the overall insecticidal activity. In general, solvent type dominantly determined the insecticidal activity, where four products in oil-based solvent system showed greater mortality (97.5% in average) than water-based aerosols (38.3% in average) against the mosquitoes located at the far side of the test chamber. The contribution of solvent type and nozzle orifice size were further examined with the sample aerosols, and the orifice size were determined more influential to the spray distance. Regardless of solvent types, the sample products attached to a bigger actuator (0.96 mm in diameter) showed greater knock-down activity (>98%) than the smaller ones (0.48 mm, 62.5% in average) to the back panel in the chamber. On the other hand, solvent system significantly affected the residual activity, as the oil-based and water-based aerosols showed 2.3- and 4.8-fold decrease in KT50 values, respectively, between 1 and 10 min after the spray.


Subject(s)
Aedes , Insecticides , Aerosols , Animals , Female
3.
J Prosthet Dent ; 115(5): 547-50, 2016 May.
Article in English | MEDLINE | ID: mdl-26794697

ABSTRACT

More natural dental esthetics have been sought by patients who wear conventional complete or partial dentures. Recently, gingiva-shade composite resins (GSCRs) have become available for replicating soft tissue for both fixed and removable prostheses. The technique presented is for fabricating individualized complete dentures. First the acrylic resin is mixed with a coloring agent and processed to modify the base shade of the denture. GSCRs are light polymerized onto a prepared space on the buccal surfaces of denture base to replicate the appearance of gingival tissues including blood vessels. The technique provides an outstanding natural, gingiva-like, appearance and allows complete dentures to harmonize with the individual patient's surrounding oral tissues.


Subject(s)
Composite Resins/therapeutic use , Dental Prosthesis Design/methods , Denture, Complete , Esthetics, Dental , Gingiva/anatomy & histology , Color , Humans
4.
J Med Entomol ; 51(4): 817-23, 2014 Jul.
Article in English | MEDLINE | ID: mdl-25118414

ABSTRACT

Culex pipiens molestus Forskal (Diptera: Culicidae) is the dominant mosquito species in septic tanks in South Korea. An assessment was made of the biological control potential of mud loaches, Misgurnus mizolepis Günther (Cypriniformes: Cobitidae), toward Cx. p. molestus larvae in laboratory and septic tanks. Results were compared with those of temephos 20% emulsifiable concentrate. In laboratory tests, all mud loaches survived on sedimentation chamber- and effluent chamber-collected water of aerobic septic tanks (ASTs), whereas all mud loaches died within 3-12 h after introduction into sedimentation chamber- and effluent chamber-collected water of anaerobic septic tanks, Gill hyperplasia and hemorrhages at the bases of pectoral fins were detected in all dead mud loaches. These appeared to have been caused by bacterial disease, rather than the physical and chemical characteristics of the septic tank water. A mud loach consumed an average range of 1,072-1,058 larvae of Cx. p. molestus in the AST water at 24 h. At the manufacturer's recommended rate (10 ml/ton) in the AST water, the temephos formulation did not cause fish mortality. In the AST experiment, predation of mosquito larvae by mud loaches at a release rate of one fish per 900 mosquito larvae resulted in complete mosquito control from the third day after treatment throughout the 18-wk survey period, compared with temephos 20% emulsifiable concentrate-treated AST water (reduction rate, 40% at 28 days after treatment). Reasonable mosquito control in aerobic septic tanks can be achieved by mosquito breeding season stocking of a rate of one mud loach per 900 mosquito larvae.


Subject(s)
Culex , Cypriniformes , Pest Control, Biological , Predatory Behavior , Animals , Insecticides , Mice , Temefos , Toxicity Tests , Wastewater/toxicity
5.
J Nanosci Nanotechnol ; 12(2): 1453-6, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22629977

ABSTRACT

Silicon dioxide (SiO2) thin films have gained considerable attention because of their various industrial applications. For example, SiO2 thin films are used in superhydrophilic self-cleaning surface glass, UV protection films, anti-reflection coatings, and insulating materials. Recently, many processes such as vacuum evaporation, sputtering, chemical vapor deposition, and spin coating have been widely applied to prepare thin films of functionally graded materials. However, these processes suffer from several engineering problems. For example, a special apparatus is required for the deposition of films, and conventional wet processes are not suitable for coating the surfaces of substrates with a large surface area and complex morphology. In this study, we investigated the film morphology and optical properties of SiO2 films prepared by a novel technique, namely, liquid phase deposition (LPD). Images of the SiO2 films were obtained by scanning electron microscopy (SEM) and atomic force microscopy (AFM) in order to study the surface morphology of these films: these images indicate that films deposited with different reaction times were uniform and dense and were composed of pure silica. Optical properties such as refractive index and transmittance were estimated by UV-vis spectroscopy and ellipsometry. SiO2 films with porous structures at the nanometer scale (100-250 nm) were successfully produced by LPD. The deposited film had excellent transmittance in the visible wavelength region.

6.
Inorg Chem ; 49(11): 5072-8, 2010 Jun 07.
Article in English | MEDLINE | ID: mdl-20450203

ABSTRACT

Amphiphilic, Fe(4)S(4) cluster core dendrimers can be prepared via ligand exchange with dendrons containing carboxylic acid peripheral groups and a thiol focal group. These amphiphilic dendrons are more susceptible to oxidative disulfide formation than their non-amphiphilic analogues reported previously. Thus, an in situ deprotection of an aromatic thioacetate was necessary to prepare the dendrimers. These molecules showed the expected decrease in rate with increasing generation. A slower rate of heterogeneous electron transfer was found when these molecules were compared with non-amphiphilic analogues. This behavior correlated with their larger size and thus a larger effective distance of electron transfer. Voltammetry in DMSO with added water makes the dendrimers easier to reduce, but the change in redox potential is much smaller for all dendrimers when compared to a non-dendritic analogue. This behavior is consistent with the idea that the dendrimers encapsulate the cluster to some degree, creating a hydrophobic microenvironment around the cluster.

7.
J Med Entomol ; 46(6): 1420-3, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19960690

ABSTRACT

The toxicity of several compounds isolated from Asarum heterotropoides root steam distillate to third-instar larvae of Culex pipiens pallens Coquillett, Aedes aegypti (L.), and Ochlerotatus togoi Theobald was examined using a direct contact mortality bioassay. Safrole was the most toxic constituent to Cx. p. pallens and Ae. aegypti larvae, whereas terpinolene was most toxic to Oc. togoi. However, LC50 values of these three mosquito larvae to both essential oils as well as the remainder of the 26 compounds identified in A. heterotropoides were considerably greater than for fenthion or temephos. However, we suggest that constituents of A. heterotropoides root steam distillate merit further study as potential mosquito larvicides due to global efforts to reduce the level of highly toxic synthetic pesticides in the aquatic environment.


Subject(s)
Aedes/growth & development , Asarum/chemistry , Culex/growth & development , Insecticides , Ochlerotatus/growth & development , Animals , Larva , Lethal Dose 50 , Oils, Volatile/chemistry , Oils, Volatile/isolation & purification , Plant Roots/chemistry
8.
Anat Rec (Hoboken) ; 292(1): 123-30, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19115389

ABSTRACT

Epithelial-mesenchymal interactions are essential for tissue patterning during organogenesis. Distal lung epithelium and its adjacent mesenchyme comprise the epithelial-mesenchymal signaling unit that regulates lung branching morphogenesis. Tissue recombination experiments have demonstrated the importance of mesenchymal signals in inducing lung epithelial differentiation and branching, but the role of the epithelium in regulating mesenchymal signals has not been well characterized. Using transgenic mice, we ablated distal lung epithelial cells during lung development by inducing the expression of a constitutively active proapoptotic Bax protein under the surfactant protein C (SP-C) promoter. We found that epithelial cell ablation results in impaired lung branching morphogenesis, which progresses to emphysematous airspaces in the adults. Mesenchymal expression of fibroblast growth factor 10 (Fgf-10), whose strict spatial and temporal expression is critical for proper lung branching morphogenesis, is disrupted and loses its localized pattern. Interestingly, the expression of sonic hedgehog (Shh), an epithelial gene known to modulate Fgf-10 expression, is unchanged, indicating the existence of other distal epithelial signals that regulate mesenchymal Fgf-10expression. We propose that distal SP-C expressing lung epithelial cells provide essential signals for the downregulation of Fgf-10 expression in the distal mesenchyme during lung development. 292:123-130, 2009. (c) 2008 Wiley-Liss, Inc.


Subject(s)
Fibroblast Growth Factor 10/biosynthesis , Lung/cytology , Lung/metabolism , Morphogenesis/physiology , Respiratory Mucosa/cytology , Respiratory Mucosa/metabolism , Ablation Techniques/methods , Animals , Female , Humans , Lung/growth & development , Mice , Mice, Transgenic , Pregnancy , Pulmonary Emphysema/etiology , Pulmonary Emphysema/metabolism , Pulmonary Emphysema/pathology , Respiratory Mucosa/growth & development
9.
Pest Manag Sci ; 64(8): 857-62, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18324612

ABSTRACT

BACKGROUND: This study was aimed at assessing the toxicity of ethyl cinnamate and ethyl p-methoxycinnamate (EMC) identified in Kaempferia galangal L. (Zingiberaceae) rhizome and another 12 known compounds to third-instar larvae from laboratory-reared Culex pipiens pallens Forskal, Aedes aegypti L. and Ochlerotatus togoi Theobald and field-collected C. pipiens pallens (Jinhae colony). Results were compared with those for fenthion and temephos. RESULTS: Ethyl p-methoxycinnamate was the most toxic of the test compounds to larvae of the three mosquito species (LC(50) 12.3-20.7 mg L(-1)) but less toxic than either fenthion (0.0096-0.021 mg L(-1)) or temephos (0.0039-0.0079 mg L(-1)). Ethyl cinnamate and 3-carene were highly active against C. pipiens pallens larvae (24.1 and 21.6 mg L(-1)) but less toxic to A. aegypti and O. togoi larvae (ca 40 and 60 mg L(-1) respectively). The toxicity of these compounds to larvae from the Jinhae colony of C. pipiens pallens was almost the same as their toxicity to the laboratory-reared larvae, although the larvae from the colony exhibited low levels of resistance to fenthion (resistance ratio 9.1) and temephos (5.8). CONCLUSION: Kaempferia galanga rhizome-derived materials, particularly ethyl p-methoxycinnamate, merit further study as potential mosquito control agents for protection of humans and domestic animals from vector-borne diseases and nuisance caused by mosquitoes.


Subject(s)
Cinnamates/pharmacology , Culicidae/drug effects , Insecticides/pharmacology , Mosquito Control , Aedes/drug effects , Animals , Culex/drug effects , Larva/drug effects , Ochlerotatus/drug effects , Rhizome/chemistry , Zingiberaceae/chemistry
10.
J Prev Med Public Health ; 39(6): 462-8, 2006 Nov.
Article in Korean | MEDLINE | ID: mdl-17168198

ABSTRACT

OBJECTIVES: The purpose of this study was to gain an understanding of the effects of three exercise types on anthropometric and serum lipids and physiological index factors, which are known to be the three risk factors of cardiovascular disease in male workers. METHODS: The experimental study period was 12 weeks. In this study, 30-40's males (N=31) were assigned to 3 experimental groups: regular aerobic(treadmill walking) exercise group, regular anaerobic(muscular endurance) exercise group, irregular aerobic & anaerobic exercise group and a control group using a stratified random assignment method. RESULTS: In relation to anthropometric factors, the regular aerobic & anaerobic exercise groups showed significant decreases in Weight, Broca's index, WC, BMI, WHtR, WHpR and HRrest. With regard to the serum lipid factors, the TC was decreased, but the HDL-c increased among the regular aerobic & anaerobic exercise groups. However, no significant difference was found between the other groups in respect to the LDL-c and TG. Considering the physiological factors, the TC/HDL-c, TC-HDL/HDL-c, LDL-c/HDL-c and NON-HDL-c ratios were decreased, but the HDL-c/TC ratio increased among the regular aerobic & anaerobic exercise groups. The TG/HDL-c and HDL-c/LDL-c ratios showed no significant differences between the groups. These results indicated that the positive change for each factor is much larger in the regular exercise groups, especially in the anaerobic exercise group. CONCLUSIONS: The results indicate that not only regular aerobic exercise, but also regular anaerobic (muscular endurance) exercise could be utilized in lessening the deleterious effects of the risk index factors for cardiovascular disease.


Subject(s)
Cardiovascular Diseases/physiopathology , Exercise , Adult , Anthropometry , Body Weights and Measures , Humans , Lipids/blood , Male , Risk Factors
11.
Stud Health Technol Inform ; 122: 967-8, 2006.
Article in English | MEDLINE | ID: mdl-17102491

ABSTRACT

Assisting diabetes patients to self manage blood glucose test and insulin injection is of great importance for their healthcare. This study presented a PDA based system to manage the personal glucose level data interfaced with a small glucometer through a serial port. The data stored in the PDA can be transmitted by cradle or wireless communication to the remote web-server, where further medical analysis and service is provided. This system enables more efficient and systematic management of diabetes patients through self management and remote medical practice.


Subject(s)
Computers, Handheld , Diabetes Mellitus , Self Care , Blood Glucose Self-Monitoring/instrumentation , Humans , Korea
12.
Birth Defects Res C Embryo Today ; 78(1): 80-9, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16622850

ABSTRACT

Epithelial-mesenchymal interactions and extracellular matrix remodeling are key processes of embryonic lung development. Lung smooth muscle cells, which are derived from the mesenchyme, form a sheath around bronchi and blood vessels. During lung organogenesis, smooth muscle differentiation coincides with epithelial branching morphogenesis and closely follows developing airways spatially and temporally. The precise function of parabronchial smooth muscle (PBSM) cells in healthy adult lung remains unclear. However, PBSM may regulate epithelial branching morphogenesis during lung development by the induction of mechanical stress or through regulation of paracrine signaling pathways. Alveolar myofibroblasts are interstitial contractile cells that share features and may share an origin with smooth muscle cells. Alveolar myofibroblasts are essential for secondary septation, a process critical for the development of the gas-exchange region of the lung. Dysregulation of PBSM or alveolar myofibroblast development is thought to underlie the pathogenesis of many lung diseases, including bronchopulmonary dysplasia, asthma, and interstitial fibrosis. We review the current understanding of the regulation of PBSM and alveolar myofibroblast development, and discuss the role of PBSM in lung development. We specifically focus on the role of these cells in the context of fibroblast growth factor-10, sonic hedgehog, bone morphogenetic protein-4, retinoic acid, and Wnt signaling pathways in the regulation of lung branching morphogenesis.


Subject(s)
Bronchi/cytology , Fibroblasts/cytology , Myocytes, Smooth Muscle/cytology , Organogenesis , Pulmonary Alveoli/cytology , Animals , Bone Morphogenetic Protein 4 , Bone Morphogenetic Proteins/metabolism , Bronchi/embryology , Extracellular Matrix/physiology , Fibroblast Growth Factor 10/metabolism , Hedgehog Proteins , Humans , Lung Diseases/metabolism , Lung Diseases/physiopathology , Pulmonary Alveoli/embryology , Trans-Activators/metabolism , Tretinoin/metabolism , Wnt1 Protein/metabolism
13.
Conf Proc IEEE Eng Med Biol Soc ; 2005: 3749-52, 2005.
Article in English | MEDLINE | ID: mdl-17281044

ABSTRACT

Diabetes is an incurable chronic disease with the prevalence high in developed countries. The number of patients in Korea is also on a steady increase. Patients have to self-manage their blood glucose level by daily test and insulin injection. Therefore, it is very important to assist them in self-management procedure. In this study, PDA(personal digital assistant) based PDMS (personal diabetes management system) was developed in the integrated environment of Visual Studio .NET 2003, which consisted of four main menus to manage personal information, diet, exercise, and blood glucose. It gives quantitative health indices, such as BMI (body mass index) and diabetes index, based on personal physical information, pedigree, and living habits. In addition, it is capable of predicting change of the body weight, which may remind patients of the importance of the disease management. The present system can be used as a mobile device within the tele-healthcare system integrated with medical center through Internet.

14.
IEEE Trans Neural Netw ; 14(5): 1065-71, 2003.
Article in English | MEDLINE | ID: mdl-18244560

ABSTRACT

This paper discusses a real-time digital signal processor (DSP)-based hierarchical neural network classifier capable of classifying both analog and digital modulation signals. A high-performance DSP processor, namely the TMS320C6701, is utilized to implement different kinds of classifiers including a hierarchical neural network classifier. A total of 31 statistical signal features are extracted and used to classify 11 modulation signals plus white noise. The modulation signals include CW, AM, FM, SSB, FSK2, FSK4, PSK2, PSK4, OOK, QAM16, and QAM32. A classification hierarchy is introduced and the genetic algorithm is employed to obtain the most effective set of features at each level of the hierarchy. The classification results and the number of operations on the DSP processor indicate the effectiveness of the introduced hierarchical neural network classifier in terms of both classification rate and processing time.

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