89 results match your criteria: "Center for Biofluid and Biomimic Research[Affiliation]"

Developmental toxicity induced by particulate matter (PM) in zebrafish (Danio rerio) model.

Aquat Toxicol

July 2021

Center for Biofluid and Biomimic Research, Pohang University of Science and Technology (POSTECH), Pohang 37673, South Korea; Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, South Korea. Electronic address:

Contemporary research in epidemiology has found that being exposed to air pollution at an early stage of life has associations with both acute and chronic conditions of the multi-organs. Nevertheless, the reasons for this have yet to be fully explained. Because of this there is a need for a robust investigation into the damaging toxic influence of diesel particulate matter (PM) on living organisms.

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Graphene-based nanomaterials (GBNs) have been widely used in various fields nowadays. However, they are reported to be highly toxic to some aquatic organisms. However, the multi-organ toxicity caused by pristine graphene (pG) and graphene oxide (GO) to the developing zebrafish (Danio rerio) larvae or juvenile and the underlying mechanisms is not fully known.

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Benzyl alcohol (BnOH) is an aromatic alcohol used worldwide as an excipient in foods, cosmetics, household products, and medications. Although BnOH is a bacteriostatic agent found in many parenteral preparations, this agent is responsible for precipitating the gasping syndrome in premature neonates. Increasing evidence of human exposure to BnOH and environmental contamination of BnOH requires a detailed toxicity assessment of this aromatic chemical.

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Deep learning-based hologram generation using a white light source.

Sci Rep

June 2020

Center for Biofluid and Biomimic Research, Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea.

Digital holographic microscopy enables the recording of sample holograms which contain 3D volumetric information. However, additional optical elements, such as partially or fully coherent light source and a pinhole, are required to induce diffraction and interference. Here, we present a deep neural network based on generative adversarial network (GAN) to perform image transformation from a defocused bright-field (BF) image acquired from a general white light source to a holographic image.

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Herbul black henna (hair dye) have been widely used as cosmetic agents to temporarily change the color of hair. Their use was tremendously increased in the past decade. Especially, hair dye containing paraphenylenediamine (PPD) is extensively used globally because of its abundance and low cost.

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Graphene oxide (GO) has wide engineering applications in various areas, including electronics, energy storage, pharmaceuticals, nanomedicine, environmental remediation and biotechnology, because of its unique physico-chemical properties. In the present study, the risk-related information of GO was evaluated to examine the potential ecological and health risks of developmental toxicity. Although the overall developmental toxicity of GO has been well characterized in zebrafish, however, its release effect at a certain concentration of living organisms with specific cardiovascular defects remains largely elusive.

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Because molecular oxygen functions as the final acceptor of electrons during aerobic respiration and a substrate for diverse enzymatic reactions, eukaryotes employ various mechanisms to maintain cellular homeostasis under varying oxygen concentration. Human fungal pathogens change the expression of genes involved in virulence and oxygen-required metabolisms such as ergosterol (ERG) synthesis when they encounter oxygen limitation (hypoxia) during infection. The oxygen level in plant tissues also fluctuates, potentially creating hypoxic stress to pathogens during infection.

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Pristine graphene induces cardiovascular defects in zebrafish (Danio rerio) embryogenesis.

Environ Pollut

December 2018

Center for Biofluid and Biomimic Research, Pohang University of Science and Technology (POSTECH), Pohang, 37673, South Korea; Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, South Korea. Electronic address:

The multiple effect of pristine graphene (pG) toxicity on cardiovascular developmental defects was assessed using zebrafish as a model. Recently, the nanotoxicity is emerging as a critical issue, and it is more significant in embryogenesis. Especially, graphene and its derivatives have attracted a lot of interest in biomedical applications.

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Optimal Design of Needle Array for Effective Drug Delivery.

Ann Biomed Eng

December 2018

Center for Biofluid and Biomimic Research, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, South Korea.

Recently, the multi-needle drug injection has been adopted to overcome the shortcomes of conventional single-needle injection, enhancing the efficiency of drug delivery. However, the effect of needle array on the efficacy of drug delivery has not been fully elucidated. In this study, the interactions of drug analogous solution injected from a pair of needles were analyzed to examine the design criteria of effective multi-needle devices for drug delivery.

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Pressure-driven spontaneous ion concentration polarization using an ion-selective membrane.

Anal Biochem

September 2018

Center for Biofluid and Biomimic Research, Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 790-784, South Korea.

In this study, the spontaneous ion concentration polarization phenomenon induced by pressure via a cation-selective membrane was theoretically and experimentally investigated. Unlike conventional electrokinetic ion concentration polarization, which uses electric current as a driving flux of cations through the membrane, advection caused by pressure is used as a transmembrane driving flux of cations to spontaneously and stably form an ion depletion zone in the present ion concentration polarization technique. The ion depletion zone produced in a simple experimental setup was used to filter electrolyte and preconcentrate ions and microparticles.

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Graphene has been used in several fields covering from electronics to biomedicine, especially exhibiting a widespread variety of promising biological and biomedical applications. In the past decade, the biomedical applications of graphene have attracted much interest. However, the effect of pristine graphene (pG) toxicity in aquatic vertebrates has not been fully studied.

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Background And Objective: A widely used pesticide quinalphos (O, O-diethyl O-quinoxalin-2-yl phosphorothioate) may be an undesirable and persistent pollutant to non-target environments like rivers and other ecosystems. The objective of this study was to isolate a potential degradant bacterium of quinalphos from polluted soils and test its fitness under various culture conditions.

Materials And Methods: A soil bacterium strain, capable of utilizing quinalphos as its sole source of carbon and energy was isolated from soil by enrichment method on a minimal salts medium (MSM).

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Immunological consequences of ageing microvascular hemodynamic changes in view of cancer development and treatment.

Oncotarget

September 2017

Departments of Gynecologic Oncology and Reproductive Medicine and Cancer Biology, The University of Texas, MD Anderson Cancer Center, Houston, TX, USA.

Risk factors of cardiovascular diseases have long been implicated as risk factors for carcinogenesis, but clear explanations for their association have not been presented. In this article, fundamental concepts from carcinogenesis, microvascular hemodynamics, and immunity are collectively reviewed and analyzed in context of the known features of vascular ageing effects, in formulating a theory that suggests reduced microvascular immunity as an important driving factor for carcinogenesis. Furthermore, scientific, preclinical, and clinical evidence that support this new theory are presented in an interdisciplinary manner, offering new explanations to previously unanswered factors that impact cancer risks and its treatment outcome such as chronic drug use, temperature, stress and exercise effects among others.

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Disease-mediated mosquitoes have been receiving much attention, as the World Health Organization recently declared the Zika virus a global public health emergency. Mosquitoes transmit pathogens that cause various tropical diseases including malaria, dengue fever and yellow fever as well as Zika virus. The vector efficiency of mosquitoes depends on their blood-feeding characteristics and the mechanics of their blood-sucking pump system, but only a few studies have attempted to investigate these key issues.

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Synthetic pyrethroid-fenvalerate-is one of the most widespread toxic pollutants and has adverse effect on living systems. However, little is known about its biotransformation mechanism in different microorganisms. To elucidate the pathway that might be involved in the catabolism of fenvalerate, we used strain XJU-4 (3-nitrobenzoate degrading organism) as an ideal fenvalerate degrading bacterium.

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Elevated blood homocysteine (Hcy) level is frequently observed in aged individuals and those with age-related vascular diseases. However, its effect on peripheral microcirculation is still not fully understood. Using zebrafish model, the degree of Hcy-induced peripheral microcirculation dysfunction is assessed in this study with a proposed dimensionless velocity parameter [Formula: see text], where [Formula: see text] and [Formula: see text] represent the peripheral microcirculation perfusion and the systemic perfusion levels, respectively.

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The objective of this study was to determine the effect of application of pesticides on morphology, viability, and germination of pollen grains of Blackberry (Rubus glaucus Benth.) and Tree tomato (Solanum betaceum Cav.).

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The present study was aimed to evaluate the modulatory effects of hydroalcoholic extract of Caralluma fimbriata (CFE) by assaying the activities of key enzymes of carbohydrate metabolism and changes in glycogen content (liver and muscle) in high-fat (HF) diet-induced diabetic rats. In vitro glucose uptake studies were carried out in both psoas muscle and adipose tissue. The inhibitory effect of the extract on α-amylase was determined in in vitro studies.

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Nearly Perfect Durable Superhydrophobic Surfaces Fabricated by a Simple One-Step Plasma Treatment.

Sci Rep

May 2017

Center for Biofluid and Biomimic Research, Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang, 790-784, Republic of Korea.

Fabrication of superhydrophobic surfaces is an area of great interest because it can be applicable to various engineering fields. A simple, safe and inexpensive fabrication process is required to fabricate applicable superhydrophobic surfaces. In this study, we developed a facile fabrication method of nearly perfect superhydrophobic surfaces through plasma treatment with argon and oxygen gases.

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Mosquito-borne diseases, such as malaria, dengue fever, and Zika virus, are serious global health issues. Vector control may be an important strategy in reducing the mortality caused by these diseases. The respiratory system of mosquito larvae in the water has to inhale atmospheric oxygen as aquatic organisms.

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Mosquitoes act as a vector for the transmission of disease. The World Health Organization has recommended strict control of mosquito larvae because of their "few, fixed, and findable" features. The respiratory system of mosquito larvae and pupae in the water has a weak point.

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Floating of the lobes of mosquito (Aedes togoi) larva for respiration.

Sci Rep

February 2017

Department of Mechanical Engineering, Pohang University of Science and Technology, Pohang Gyeongbuk, Republic of Korea.

Mosquito (Aedes togoi) larva has to float its siphon on the water surface to breathe air. To elucidate the floating mechanism of the siphon, morphological structures, especially the flap-like lobes and spiracle of the siphon, were observed. Wettability and dynamic behavior of the lobes on the water surface were also experimentally examined.

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Focusing and alignment of erythrocytes in a viscoelastic medium.

Sci Rep

January 2017

Center for Biofluid and Biomimic Research, Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 790-784, South Korea.

Viscoelastic fluid flow-induced cross-streamline migration has recently received considerable attention because this process provides simple focusing and alignment over a wide range of flow rates. The lateral migration of particles depends on the channel geometry and physicochemical properties of particles. In this study, digital in-line holographic microscopy (DIHM) is employed to investigate the lateral migration of human erythrocytes induced by viscoelastic fluid flow in a rectangular microchannel.

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In vivo measurement of hemodynamic information in stenosed rat blood vessels using X-ray PIV.

Sci Rep

November 2016

Center for Biofluid and Biomimic Research, Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 790-784, South Korea.

Measurements of the hemodynamic information of blood flows, especially wall shear stress (WSS), in animal models with circulatory vascular diseases (CVDs) are important to understand the pathological mechanism of CVDs. In this study, X-ray particle image velocimetry (PIV) with high spatial resolution was applied to obtain velocity field information in stenosed blood vessels with high WSS. 3D clips fabricated with a 3D printer were applied to the abdominal aorta of a rat cadaver to induce artificial stenosis in the real blood vessel of an animal model.

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Compact and Thermosensitive Nature-inspired Micropump.

Sci Rep

October 2016

Center for Biofluid and Biomimic Research, Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 790-784, South Korea.

Liquid transportation without employing a bulky power source, often observed in nature, has been an essential prerequisite for smart applications of microfluidic devices. In this report, a leaf-inspired micropump (LIM) which is composed of thermo-responsive stomata-inspired membrane (SIM) and mesophyll-inspired agarose cryogel (MAC) is proposed. The LIM provides a durable flow rate of 30 μl/h · cm for more than 30 h at room temperature without external mechanical power source.

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