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1.
Biomimetics (Basel) ; 8(3)2023 Jul 03.
Article in English | MEDLINE | ID: mdl-37504176

ABSTRACT

This study examines the current technological level and industrial/technical trends in the field of biomimicry technology, as well as recent technological and research and development trends. Patent analysis was conducted, focusing on technology that uses design elements and biological/ecological characteristics to provide solutions to technological problems. The technological scope of the analysis included the field of technologies and materials that apply to the conditions found in ecology, as well as robot machines and devices designed to mimic certain animals and ecological elements. The search for patents was conducted in Korea, the United States, Japan, and Europe from 1975 to 2021, resulting in a total of 8278 raw data cases, from which 940 valid patents were selected. The percentage of patent document and the status of both domestic and foreign applicants varied among the countries of Korea, the United States, Japan, and Europe. Based on the results of the patent analysis, it was found that biomimicry technology is in a growth phase that is expected to continue in the future and that Korea and the United States are leading the development of this technology.

2.
ACS Appl Mater Interfaces ; 14(50): 55989-55996, 2022 Dec 21.
Article in English | MEDLINE | ID: mdl-36503219

ABSTRACT

Biological cilia have exquisitely organized dynamic ultrafine structures with submicron diameters and exceptional aspect ratios, which are self-assembled with ciliary proteins. However, the construction of artificial cilia with size and dynamic functions comparable to biological cilia remains highly challenging. Here, we propose a self-assembly technique that generates magnetoresponsive artificial cilia with a highly ordered 3D structural arrangement using vapor-phase magnetic particles of varying sizes and shapes. We demonstrate that both monodispersed Fe3O4 nanoparticles and Fe microparticles can be assembled layer-by-layer vertically in patterned magnetic fields, generating both "nanoscale" or "microscale" artificial cilia, respectively. The resulting cilia display several structural features, such as diameters of single particle resolution, controllable diameters and lengths spanning from nanometers to micrometers, and accurate positioning. We further demonstrate that both the magnetic nanocilia and microcilia can dynamically and immediately actuate in response to modulated magnetic fields while providing different stroke ranges and actuation torques. Our strategy provides new possibilities for constructing artificial nano- and microcilia with controlled 3D morphology and dynamic field responsiveness using magnetic particles of varied sizes and shapes.


Subject(s)
Cell-Derived Microparticles , Nanoparticles , Cilia/physiology , Magnetic Fields , Magnetics , Nanoparticles/chemistry
3.
Plants (Basel) ; 9(10)2020 Oct 12.
Article in English | MEDLINE | ID: mdl-33053691

ABSTRACT

In order to better understand the functions of plants, it is important to analyze the internal structure of plants with a complex structure, as well as to efficiently monitor the morphology of plants altered by their external environment. This anatomical study investigated structural characteristics of pinecones to provide detailed descriptions of morphological specifications of complex cone scales. We analyzed cross-sectional image data and internal movement patterns in the opening and closing motions of pinecones, which change according to the moisture content of its external environment. It is possible to propose a scientific system for the deformation of complex pinecone for the variable structures due to changes in relative humidity, as well as the application of technology. This study provided a functional principle for a multidisciplinary approach by exploring the morphological properties and anatomical structures of pinecones. Therefore, the results suggest a potential application for use in energy-efficient materials by incorporating hygroscopic principles into engineering technology and also providing basic data for biomimicry research.

4.
Article in English | MEDLINE | ID: mdl-27021832

ABSTRACT

PURPOSE: Presenteeism is a relatively new concept in nursing describing the condition within which registered nurses (RNs) come to work while they are sick. The purpose of this study was to explore and describe presenteeism experiences among RNs in South Korea. METHODS: In this constructivist grounded theory study, a focus group interview (FGI) technique was utilized for data collection. A total of 20 RNs at one hospital in Chuncheon city joined in three different FGIs. Semistructured questions were asked in reference to their sickness experience in the workplace. Data analysis was conducted according to the constructivist grounded theory methodology. RESULTS: All participants had experiences of presenteeism. The overriding theme was "having no caring for nurses leads to losing one's nursing mind". The participants reported that due to either their personal preference or peer pressure they showed up to work, but they felt sad and their pride was hurt by the fact that there was no caring for them from other nurses. This emotional exhaustion often led to the loss of compassion and the resignation of nursing staff. CONCLUSIONS: Care for nurses in the workplace is necessary for RNs to make their presenteeism experience positive and even effective.


Subject(s)
Attitude of Health Personnel , Nursing Staff, Hospital/psychology , Presenteeism , Workplace/psychology , Adult , Female , Grounded Theory , Humans , Male , Middle Aged , Qualitative Research , Republic of Korea , Surveys and Questionnaires
5.
J Phys Ther Sci ; 26(2): 195-7, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24648630

ABSTRACT

[Purpose] This study verified the changes in muscle activities and grasping power during maximal isometric exercise of the forearm and masseter muscle with and without a mandibular orthopedic repositioning appliance (MORA). It also offers basic data for defining the correlation of function of hand with mouth. [Methods] EMG was used to measure masticatory muscle, flexor bundle and extensor bundle activities with or without MORA while subjects performed the hook grip and pinch grip. The measuring tool used for measuring grip strength was the same as that used for measuring pinch and hook strength. The subjects were 28 healthy young adults. [Result] Muscle activity and grasping power significantly increased when wearing the MORA. [Conclusion] The result indicates that wearing MORA can increase muscle activity and grasping power of forearm and masseter muscle. We think wearing MORA might help improve the function of the forearm because it activates the function of the masseter.

6.
J Chromatogr Sci ; 51(5): 412-8, 2013.
Article in English | MEDLINE | ID: mdl-23081967

ABSTRACT

The development of simultaneous extraction and determination of bioactive molecules from natural products is becoming more popular. The present study reports the development of a method for the simultaneous extraction and determination of both capsaicinoids and ascorbic acid in peppers. Capsaicin (341.61 µg/g), dihydrocapsaicin (119.91 µg/g) and ascorbic acid (2,109.60 µg/g) were extracted with 3% metaphosphoric acid-ethanol (2:8) as a solvent. The efficient extraction of capsaicinoids (412.61 µg/g) and ascorbic acid (2,785.93 µg/g) was achieved at a sample-to-solvent ratio of 1:8 after 30 minutes of sonication. Simultaneous separation of capsaicinoids and ascorbic acid was achieved using a Gemini C18 column with a gradient elution of 0.03M phosphoric acid and methanol. Capsaicinoids and ascorbic acid were simultaneously detected at 282 and 254 nm, respectively. The recovery of capsaicinoids ranged from 96.21 to 108.71%, and the recovery of ascorbic acid ranged from 97.01 to 98.83%. The limits of detection for capsaicin, dihydrocapsaicin and ascorbic acid were 0.24, 0.21 and 0.26 µg, respectively. Relative standard deviation for the intra-day and inter-day variability in the results was less than 3%, indicating that the method produced highly reproducible results. Therefore, this method enables the reproducible, simultaneous separation and quantification of capsaicinoids and ascorbic acid from peppers.


Subject(s)
Ascorbic Acid/analysis , Capsaicin/analysis , Capsicum/chemistry , Chemical Fractionation/methods , Chromatography, High Pressure Liquid/methods , Ascorbic Acid/isolation & purification , Capsaicin/isolation & purification , Capsicum/growth & development , Sensitivity and Specificity , Vegetables/chemistry
7.
Plant Foods Hum Nutr ; 67(2): 120-8, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22569831

ABSTRACT

Bioactive compounds in foods have been shown to maintain human health. However, the relative amounts of bioactive compounds and the variation in the amounts are still poorly understood. In this study, the efficacy of different extraction solvents (hexane, ethyl acetate, acetone, methanol, and a methanol:water mixture), as well as the levels of certain bioactive compounds in non-pungent pepper cultivars (TMH, TMJ, PA137, and B58) were investigated using high-performance liquid chromatography (HPLC). Antioxidant activities were determined using 2,2,-diphenyl-1-picrylhydrazyl (DPPH), reducing power, and deoxyribose degradation. Hexane extracts had the highest level of carotenoids (47.2-628.8 µg/g), and methanol extracts contained maximum flavonoids (24.9-152.2 µg/g) in four different cultivars. Higher DPPH scavenging activity was found in the hexane extracts from TMH, TMJ, PA137, and B58 (IC50 value: 0.67, 0.74, 0.55, and 0.48 µg/ml, respectively), whereas the reducing power was high in ethyl acetate and acetone extracts. Inhibition of deoxyribose degradation was highest in methanolic extracts from TMH, TMJ, PA137, and B58 (51.2, 49.5, 52.6, and 47.4 %, respectively). These data demonstrate that solvent chemical properties such as polarity can differentially impact the efficiency with which different bioactive compounds are recovered from foods, and this could lead to differences in estimated biological activity such as antioxidant capacity.


Subject(s)
Antioxidants/pharmacology , Oxidation-Reduction , Piper nigrum/chemistry , Plant Extracts/pharmacology , Solvents/chemistry , Acetone/chemistry , Antioxidants/analysis , Biphenyl Compounds/metabolism , Carotenoids/analysis , Carotenoids/pharmacology , Chromatography, High Pressure Liquid/methods , Flavonoids/analysis , Flavonoids/pharmacology , Hexanes/chemistry , Methanol/chemistry , Phenols/analysis , Phenols/pharmacology , Picrates/metabolism , Vegetables/chemistry
8.
Food Chem ; 134(4): 1912-8, 2012 Oct 15.
Article in English | MEDLINE | ID: mdl-23442638

ABSTRACT

Peppers (Capsicum spp.) are a rich source of diverse bioactive compounds with potential health-promoting properties. This study investigated the extraction efficiency of five solvents on antioxidant activities from cayenne (CA408 and Mesilla), jalapeño (Ixtapa) and serrano (Tuxtlas) pepper cultivars. Freeze-dried peppers were extracted using a Soxhlet extractor with five solvents: hexane, ethyl acetate, acetone, methanol, and methanol:water (80:20). The levels of specific bioactive compounds (phenolics, capsaicinoids, carotenoids and flavonoids) were determined by HPLC and antioxidant activities were assayed by three methods. For all pepper cultivars tested, hexane extracts had the highest levels of capsaicinoids and carotenoids, but methanol extracts had the maximum levels of flavonoids. Hexane extracts showed higher 2,2-diphenyl-1-pricrylhydrozyl (DPPH) radical-scavenging activity and higher reducing power, and acetone extracts (from Mesilla pepper) had a high reducing power. All pepper extracts, except hexane, were effective in preventing deoxyribose degradation, and the inhibition was increased by high concentrations of extracts. The results of the present study indicated that, among the different measures of antioxidant activity, DPPH radical-scavenging activity was strongly correlated with total bioactive compounds (capsaicinoids, carotenoids, flavonoids and total phenolics) in pepper cultivars.


Subject(s)
Antioxidants/chemistry , Capsicum/chemistry , Plant Extracts/chemistry , Antioxidants/isolation & purification , Capsicum/classification , Chromatography, High Pressure Liquid , Hydrophobic and Hydrophilic Interactions , Plant Extracts/isolation & purification , Vegetables/chemistry
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