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1.
Molecules ; 28(18)2023 Sep 20.
Article in English | MEDLINE | ID: mdl-37764491

ABSTRACT

Hispidulin is a natural bioactive flavonoid that has been studied for its potential therapeutic properties, including its anti-inflammatory, antioxidant, and neuroprotective effects. The aim of this study was to explore whether hispidulin could inhibit the endothelial inflammation triggered by Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide (LPS). The adhesion of monocytes to the vascular endothelium was evaluated through in vitro and ex vivo monocyte adhesion assays. We analyzed the migration of monocytes across the endothelial layer using a transmigration assay. The results showed that treatment with hispidulin decreased the P. gingivalis LPS-induced adhesion of monocytes to endothelial cells and their migration by suppressing the P. gingivalis LPS-triggered expression of intercellular adhesion molecule-1 (ICAM-1) through downregulating nuclear factor-қB (NF-қB). In addition, hispidulin inhibited P. gingivalis LPS-induced mitogen-activated protein kinases (MAPKs) and AKT in endothelial cells. Altogether, the results indicate that hispidulin suppresses the vascular inflammation induced by P. gingivalis LPS. Mechanistically, it prevents the adhesion of monocytes to the vascular endothelium and migration and inhibits NF-қB, MAPKs, and AKT signaling in endothelial cells.


Subject(s)
Lipopolysaccharides , Porphyromonas gingivalis , Humans , Porphyromonas gingivalis/metabolism , Lipopolysaccharides/pharmacology , Endothelial Cells , Proto-Oncogene Proteins c-akt/metabolism , Mitogen-Activated Protein Kinases/metabolism , Monocytes , Inflammation/drug therapy , Inflammation/metabolism , Intercellular Adhesion Molecule-1/metabolism , NF-kappa B/metabolism
2.
Neuromodulation ; 25(7): 970-979, 2022 Oct.
Article in English | MEDLINE | ID: mdl-34096146

ABSTRACT

OBJECTIVES: Dorsal root ganglion (DRG) stimulation is effective in treating chronic pain. While burst stimulation has been proven to enhance the therapeutic efficacy in spinal cord stimulation, currently only a tonic stimulation waveform is clinically used in DRG stimulation. We hypothesized that burst DRG stimulation might also produce analgesic effect in a preclinical neuropathic pain model. We evaluated both the therapeutic effects of burst DRG stimulation and the possible effects of DRG stimulation upon inflammation within the DRG in a preclinical neuropathic pain model. MATERIALS AND METHODS: Rats received either a painful tibial nerve injury or sham surgery. Analgesic effects of DRG stimulation were evaluated by testing a battery of evoked pain-related behaviors as well as measuring the positive affective state associated with relief of spontaneous pain using conditioned place preference. Histological evidence for neuronal trauma or neuroinflammation was evaluated. RESULTS: All of the waveforms tested (20 Hz-tonic, 20 Hz-burst, and 40 Hz-burst) have similar analgesic effects in sensory tests and conditioned place preference. Long-term DRG stimulation for two weeks does not change DRG expression of markers for nerve injury and neuroinflammation. CONCLUSIONS: DRG stimulation using burst waveform might be also suitable for treating neuropathic pain.


Subject(s)
Neuralgia , Peripheral Nerve Injuries , Analgesics , Animals , Ganglia, Spinal/physiology , Neuralgia/metabolism , Neuralgia/therapy , Peripheral Nerve Injuries/metabolism , Rats , Rats, Sprague-Dawley , Tibial Nerve
3.
Neuromodulation ; 25(1): 53-63, 2022 01.
Article in English | MEDLINE | ID: mdl-35041588

ABSTRACT

OBJECTIVE: The objective of this preclinical study was to examine the responses of the brain to noxious stimulation in the presence and absence of different modes of spinal cord stimulation (SCS) using blood-oxygen-level-dependent functional magnetic resonance imaging (BOLD-fMRI). MATERIALS AND METHODS: Sprague-Dawley rats were randomized to groups based on the mode of SCS delivered which included tonic stimulation (n = 27), burst stimulation (n = 30), and burst-cycle stimulation (n = 29). The control (sham) group (n = 28) received no SCS. The SCS electrode was inserted between T10 and T12 spinal levels prior to fMRI session. The experimental protocol for fMRI acquisition consisted of an initial noxious stimulation phase, a treatment phase wherein the SCS was turned on concurrently with noxious stimulation, and a residual effect phase wherein the noxious stimulation alone was turned on. The responses were statistically analyzed through paired t-test and the results were presented as z-scores for the quantitative analysis of the fMRI data. RESULTS: The treatment with different SCS modes attenuated the BOLD brain responses to noxious hindlimb stimulation. The tonic, burst, and burst-cycle SCS treatment attenuated BOLD responses in the caudate putamen (CPu), insula (In), and secondary somatosensory cortex (S2). There was little to no corresponding change in sham control in these three regions. The burst and burst-cycle SCS demonstrated greater attenuation of BOLD signals in CPu, In, and S2 compared to tonic stimulation. CONCLUSION: The high-resolution fMRI study using a rat model demonstrated the potential of different SCS modes to act on several pain-matrix-related regions of the brain in response to noxious stimulation. The burst and burst-cycle SCS exhibited greater brain activity reduction in response to noxious hindlimb stimulation in the caudate putamen, insula, and secondary somatosensory cortex compared to tonic stimulation.


Subject(s)
Neuralgia , Spinal Cord Stimulation , Animals , Brain/diagnostic imaging , Magnetic Resonance Imaging , Rats , Rats, Sprague-Dawley , Spinal Cord/diagnostic imaging
4.
Faraday Discuss ; 226: 537-550, 2021 03 01.
Article in English | MEDLINE | ID: mdl-33346290

ABSTRACT

We present trace gas vertical profiles observed by instruments on the NASA DC-8 and at a ground site during the Korea-US air quality study (KORUS) field campaign in May to June 2016. We focus on the region near the Seoul metropolitan area and its surroundings where both anthropogenic and natural emission sources play an important role in local photochemistry. Integrating ground and airborne observations is the major research goal of many atmospheric chemistry field campaigns. Although airborne platforms typically aim to sample from near surface to the free troposphere, it is difficult to fly very close to the surface especially in environments with complex terrain or a populated area. A detailed analysis integrating ground and airborne observations associated with specific concentration footprints indicates that reactive trace gases are quickly oxidized below an altitude of 700 m. The total OH reactivity profile has a rapid decay in the lower part of troposphere from surface to the lowest altitude (700 m) sampled by the NASA DC-8. The decay rate is close to that of very reactive biogenic volatile organic compounds such as monoterpenes. Therefore, we argue that photochemical processes in the bottom of the boundary layer, below the typical altitude of aircraft sampling, should be thoroughly investigated to properly assess ozone and secondary aerosol formation.


Subject(s)
Air Pollutants , Ozone , Aerosols/analysis , Air Pollutants/analysis , Forests , Ozone/analysis , Seoul
5.
Neurol Sci ; 42(8): 3285-3296, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33387056

ABSTRACT

BACKGROUND: Spinal cord stimulation (SCS) is an established therapy for chronic neuropathic pain and most frequently utilised for Failed Back Surgery Syndrome (FBSS). BurstDR™ also known as DeRidder Burst-SCS, a novel waveform, has demonstrated superiority to conventional tonic stimulation of the thoracic spine in FBSS. There are case reports of an improvement in multidimensional pain outcomes using DeRidder Burst-SCS in the cervical spine for chronic neck and cervical radicular pain. The safety and efficacy of cervical DeRidder Burst-SCS stimulation still however remain undetermined. METHODS/DESIGN: This is a prospective, multicentre feasibility trial evaluating the safety and therapeutic efficacy of DeRidder Burst-SCS stimulation for the treatment of chronic intractable neck pain with or without radiation to the arm, shoulder, and upper back. After baseline evaluation, subjects will undergo an SCS trial using the Abbott Invisible Trial system according to standard clinical procedures. During the trial phase, SCS leads will be implanted in the cervical epidural space. At the end of the SCS trial, subjects experiencing at least 50% pain relief will be considered for permanent implant. Pain intensity, medication usage, and other multidimensional pain outcomes will be collected. The timing of these will be at baseline, end of the SCS trial and at 3-, 6-, and 12-month visits. Incidence of adverse events will be collected throughout the study duration. DISCUSSION: The results of this feasibility study will validate the efficacy and safety of DeRidder Burst-SCS stimulation in the cervical spine. The results obtained in this study will potentially be used to generate a level 1 evidence-based study with formal statistical hypotheses testing. TRIAL REGISTRATION: www.clinicaltrials.gov Identifier: NCT03159169.


Subject(s)
Failed Back Surgery Syndrome , Spinal Cord Stimulation , Arm , Humans , Prospective Studies , Spinal Cord , Treatment Outcome
6.
Am J Nephrol ; 51(7): 556-564, 2020.
Article in English | MEDLINE | ID: mdl-32610315

ABSTRACT

BACKGROUND: Polycystic kidney disease (PKD) is a hereditary disease characterized by cyst formation in the kidneys bilaterally. It has been observed that semaphorin-3C (SEMA3C) is overexpressed in polycystic kidney epithelial cells. It is hypothesized that upregulated SEMA3C would contribute to survival of polycystic kidney epithelial cells. Furthermore, as the kidney is a highly vascularized organ, the secreted SEMA3C from PKD epithelial cells will affect glomerular endothelial cells (GECs) in a paracrine manner. METHODS: To evaluate the effect of SEMA3C on renal cells, siSEMA3C-treated PKD epithelial cells were used for further analysis, and GECs were exposed to recombinant SEMA3C (rSEMA3C). Also, co-culture and treatment of conditioned media were employed to confirm whether PKD epithelial cells could influence on GECs via SEMA3C secretion. RESULTS: SEMA3C knockdown reduced proliferation of PKD epithelial cells. In case of GECs, exposure to rSEMA3C decreased angiogenesis, which resulted from suppressed migratory ability not cell proliferation. CONCLUSIONS: This study indicates that SEMA3C is the aggravating factor in PKD. Thus, it is proposed that targeting SEMA3C can be effective to mitigate PKD.


Subject(s)
Endothelial Cells/metabolism , Kidney Glomerulus/pathology , Neovascularization, Physiologic , Polycystic Kidney Diseases/pathology , Semaphorins/metabolism , Cell Culture Techniques/methods , Cell Line , Cell Movement , Cell Proliferation , Cells, Cultured , Culture Media/metabolism , Endothelial Cells/pathology , Gene Knockdown Techniques , Humans , Kidney Glomerulus/blood supply , Kidney Glomerulus/cytology , Polycystic Kidney Diseases/drug therapy , Recombinant Proteins/metabolism , Semaphorins/antagonists & inhibitors , Semaphorins/genetics , Signal Transduction , Up-Regulation
7.
Int J Mol Sci ; 20(22)2019 Nov 17.
Article in English | MEDLINE | ID: mdl-31744201

ABSTRACT

Pentraxin-3 (PTX3) is recognized as a modulator of inflammation and a mediator of tissue repair. In this study, we characterized the role of PTX3 on some biological functions of human dental pulp stem cells (HDPSCs). The expression level of PTX3 significantly increased during osteogenic/odontogenic differentiation of HDPSCs, whereas the knockdown of PTX3 decreased this differentiation. Silencing of PTX3 in HDPSCs inhibited their migration and C-X-C chemokine receptor type 4 (CXCR4) expression. Our present study indicates that PTX3 is involved in osteogenic/odontogenic differentiation and migration of HDPSCs, and may contribute to the therapeutic potential of HDPSCs for regeneration and repair.


Subject(s)
C-Reactive Protein/metabolism , Cell Differentiation , Cell Movement , Odontogenesis/physiology , Osteogenesis/physiology , Serum Amyloid P-Component/metabolism , C-Reactive Protein/genetics , Dental Pulp/growth & development , Dental Pulp/physiology , Gene Knockdown Techniques , Humans , Receptors, CXCR4/metabolism , Serum Amyloid P-Component/genetics , Stem Cells/physiology
8.
Int J Mol Sci ; 19(12)2018 Dec 10.
Article in English | MEDLINE | ID: mdl-30544709

ABSTRACT

Gastrin-releasing peptide (GRP), a member of bombesin-like peptides, and its receptor (GRP-R) play an important role in various physiological and pathological conditions. In this work, we investigated the role of GRP-R on adipogenesis in 3T3-L1 adipocytes. The expression of GRP-R was significantly increased during the adipocyte differentiation of 3T3-L1 cells. The inhibition of GRP-R by the antagonist RC-3095 affected adipogenesis in 3T3-L1 cells, which reduced lipid accumulation and regulated the expression of adipogenic genes. Moreover, cyclic AMP response element-binding protein (CREB) directly bound to the GRP-R promoter upon exposure to adipogenic stimuli. The down-regulation of GRP-R by the knockdown of CREB inhibited adipocyte differentiation of 3T3-L1 cells. Together these results suggest that the regulation of GRP-R activity or expression has an influence on adipogenesis through regulating adipogenic related genes.


Subject(s)
Adipocytes/cytology , Adipocytes/metabolism , Cell Differentiation , Receptors, Bombesin/metabolism , 3T3-L1 Cells , Adipocytes/drug effects , Adipogenesis/drug effects , Adipogenesis/genetics , Adipose Tissue/drug effects , Adipose Tissue/metabolism , Animals , Bombesin/analogs & derivatives , Bombesin/pharmacology , Cell Differentiation/drug effects , Cyclic AMP Response Element-Binding Protein/metabolism , Diet, High-Fat , Down-Regulation/drug effects , Gastrin-Releasing Peptide/metabolism , Gene Knockdown Techniques , Mice , Obesity/genetics , Peptide Fragments/pharmacology , Rats
9.
Biochem Biophys Res Commun ; 485(2): 542-549, 2017 04 01.
Article in English | MEDLINE | ID: mdl-28093230

ABSTRACT

Gastrin-releasing peptide (GRP) is a neuropeptide that plays roles in various pathophysiological conditions including inflammatory diseases in peripheral tissues; however, little is known about whether GRP can directly regulate endothelial inflammatory processes. In this study, we showed that GRP promotes the adhesion of leukocytes to human umbilical vein endothelial cells (HUVECs) and the aortic endothelium. GRP increased the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) by activating nuclear factor-κB (NF-κB) in endothelial cells. In addition, GRP activated extracellular signal-regulated kinase 1/2 (ERK1/2), p38MAPK, and AKT, and the inhibition of these signaling pathways significantly reduced GRP-induced monocyte adhesion to the endothelium. Overall, our results suggested that GRP may cause endothelial dysfunction, which could be of particular relevance in the development of vascular inflammatory disorders.


Subject(s)
Endothelium, Vascular/drug effects , Gastrin-Releasing Peptide/pharmacology , Intercellular Adhesion Molecule-1/metabolism , Monocytes/drug effects , Vascular Cell Adhesion Molecule-1/metabolism , Animals , Blotting, Western , Cell Adhesion/drug effects , Cells, Cultured , Dose-Response Relationship, Drug , Endothelium, Vascular/metabolism , Extracellular Signal-Regulated MAP Kinases/metabolism , Human Umbilical Vein Endothelial Cells/cytology , Human Umbilical Vein Endothelial Cells/drug effects , Human Umbilical Vein Endothelial Cells/metabolism , Humans , Intercellular Adhesion Molecule-1/genetics , Male , Microscopy, Fluorescence , Monocytes/cytology , Monocytes/metabolism , NF-kappa B/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Rats, Sprague-Dawley , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction/drug effects , U937 Cells , Up-Regulation/drug effects , Vascular Cell Adhesion Molecule-1/genetics , p38 Mitogen-Activated Protein Kinases/metabolism
10.
J Neurosci ; 34(27): 9040-50, 2014 Jul 02.
Article in English | MEDLINE | ID: mdl-24990924

ABSTRACT

Control over postinjury CNS plasticity is a major frontier of science that, if conquered, would open new avenues for treatment of neurological disorders. Here we investigate the functional, physiological, and structural changes in the cerebral cortex associated with chronic deep brain stimulation of the cerebellar output, a treatment approach that has been shown to improve postischemia motor recovery in a rodent model of cortical infarcts. Long-Evans rats were pretrained on the pasta-matrix retrieval task, followed by induction of focal cortical ischemia and implantation of a macroelectrode in the contralesional lateral cerebellar nucleus. Animals were assigned to one of three treatment groups pseudorandomly to balance severity of poststroke motor deficits: REGULAR stimulation, BURST stimulation, or SHAM. Treatment initiated 2 weeks post surgery and continued for 5 weeks. At the end, animals were randomly selected for perilesional intracortical microstimulation mapping and tissue sampling for Western blot analysis or contributed tissue for 3D electron microscopy. Evidence of enhanced cortical plasticity with therapeutically effective stimulation is shown, marked by greater perilesional reorganization in stimulation- treated animals versus SHAM. BURST stimulation was significantly effective for promoting distal forepaw cortical representation. Stimulation-treated animals showed a twofold increase in synaptic density compared with SHAM. In addition, treated animals demonstrated increased expression of synaptic markers of long-term potentiation and plasticity, including synaptophysin, NMDAR1, CaMKII, and PSD95. These findings provide a critical foundation of how deep cerebellar stimulation may guide plastic reparative reorganization after nonprogressive brain injury and indicate strong translational potential.


Subject(s)
Brain Ischemia/physiopathology , Cerebellar Nuclei/physiopathology , Cerebral Cortex/physiopathology , Deep Brain Stimulation , Long-Term Potentiation/physiology , Animals , Appetitive Behavior/physiology , Brain Mapping , Dominance, Cerebral , Electrodes, Implanted , Electron Microscope Tomography , Male , Nerve Tissue Proteins/physiology , Random Allocation , Rats , Rats, Long-Evans , Synapses/metabolism , Wound Healing
11.
Opt Express ; 23(12): 15792-805, 2015 Jun 15.
Article in English | MEDLINE | ID: mdl-26193558

ABSTRACT

Rapid identification of bacterial species is crucial in medicine and food hygiene. In order to achieve rapid and label-free identification of bacterial species at the single bacterium level, we propose and experimentally demonstrate an optical method based on Fourier transform light scattering (FTLS) measurements and statistical classification. For individual rod-shaped bacteria belonging to four bacterial species (Listeria monocytogenes, Escherichia coli, Lactobacillus casei, and Bacillus subtilis), two-dimensional angle-resolved light scattering maps are precisely measured using FTLS technique. The scattering maps are then systematically analyzed, employing statistical classification in order to extract the unique fingerprint patterns for each species, so that a new unidentified bacterium can be identified by a single light scattering measurement. The single-bacterial and label-free nature of our method suggests wide applicability for rapid point-of-care bacterial diagnosis.

12.
Opt Express ; 23(15): 18996, 2015 Jul 27.
Article in English | MEDLINE | ID: mdl-26367562

ABSTRACT

An erratum is presented to correct a typographical error on Fig. 1 in [Opt. Express 22(9), 10398 (2014)].

13.
Muscle Nerve ; 52(6): 1088-95, 2015 Dec.
Article in English | MEDLINE | ID: mdl-25786911

ABSTRACT

INTRODUCTION: A flat interface nerve electrode (FINE) has been shown to improve fascicular and subfascicular selectivity. A recently developed novel control algorithm for FINE was applied to motion control of the rabbit ankle. METHODS: A 14-contact FINE was placed on the rabbit sciatic nerve (n = 8), and ankle joint motion was controlled for sinusoidal trajectories and filtered random trajectories. To this end, a real-time controller was implemented with a multiple-channel current stimulus isolator. RESULTS: The performance test results showed good tracking performance of rabbit ankle joint motion for filtered random trajectories and sinusoidal trajectories (0.5 Hz and 1.0 Hz) with <10% average root-mean-square (RMS) tracking error, whereas the average range of ankle joint motion was between -20.0 ± 9.3° and 18.1 ± 8.8°. CONCLUSIONS: The proposed control algorithm enables the use of a multiple-contact nerve electrode for motion trajectory tracking control of musculoskeletal systems.


Subject(s)
Ankle Joint/physiology , Electrodes, Implanted , Movement/physiology , Sciatic Nerve/physiology , Algorithms , Animals , Electric Stimulation , Feedback, Physiological , Rabbits
14.
Korean J Physiol Pharmacol ; 19(4): 327-34, 2015 Jul.
Article in English | MEDLINE | ID: mdl-26170736

ABSTRACT

The cytoprotective enzyme heme oxygenase-1 (HO-1) influences endothelial cell survival, proliferation, inflammatory response, and angiogenesis in response to various angiogenic stimuli. In this study, we investigate the involvement of HO-1 in the angiogenic activity of orexin-A. We showed that orexin-A stimulates expression and activity of HO-1 in human umbilical vein endothelial cells (HUVECs). Furthermore, we showed that inhibition of HO-1 by tin (Sn) protoporphryin-IX (SnPP) reduced orexin-A-induced angiogenesis in vivo and ex vivo. Orexin-A-stimulated endothelial tube formation and chemotactic activity were also blocked in SnPP-treated vascular endothelial cells. Orexin-A treatment increased the expression of nuclear factor erythroid-derived 2 related factor 2 (Nrf2), and antioxidant response element (ARE) luciferase activity, leading to induction of HO-1. Collectively, these findings indicate that HO-1 plays a role as an important mediator of orexin-A-induced angiogenesis, and provide new possibilities for therapeutic approaches in pathophysiological conditions associated with angiogenesis.

15.
Opt Express ; 22(9): 10398-407, 2014 May 05.
Article in English | MEDLINE | ID: mdl-24921741

ABSTRACT

We present an optical holographic micro-tomographic technique for imaging both the three-dimensional structures and dynamics of biological cells. Optical light field images of a sample, illuminated by a plane wave with various illumination angles, are measured in a common-path interferometry, and thus both the three-dimensional refractive index tomogram and two-dimensional dynamics of live biological cells are measured with extremely high sensitivity. The applicability of the technique is demonstrated through quantitative and measurements of morphological, chemical, and mechanical parameters at the individual cell level.


Subject(s)
Cells/cytology , Holography , Interferometry/methods , Light , Refractometry/methods , Tomography, Optical/methods , Tomography, X-Ray Computed
16.
Biol Cybern ; 108(4): 445-57, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24939581

ABSTRACT

The flat interface nerve electrode (FINE) has demonstrated significant capability for fascicular and subfascicular stimulation selectivity. However, due to the inherent complexity of the neuromuscular skeletal systems and nerve-electrode interface, a trajectory tracking motion control algorithm of musculoskeletal systems for functional electrical stimulation using a multiple contact nerve cuff electrode such as FINE has not yet been developed. In our previous study, a control system was developed for multiple-input multiple-output (MIMO) musculoskeletal systems with little prior knowledge of the system. In this study, more realistic computational ankle/subtalar joint model including a finite element model of the sciatic nerve was developed. The control system was tested to control the motion of ankle/subtalar joint angles by modulating the pulse amplitude of each contact of a FINE placed on the sciatic nerve. The simulation results showed that the control strategy based on the separation of steady state and dynamic properties of the system resulted in small output tracking errors for different reference trajectories such as sinusoidal and filtered random signals. The proposed control method also demonstrated robustness against external disturbances and system parameter variations such as muscle fatigue. These simulation results under various circumstances indicate that it is possible to take advantage of multiple contact nerve electrodes with spatial selectivity for the control of limb motion by peripheral nerve stimulation even with limited individual muscle selectivity. This technology could be useful to restore neural function in patients with paralysis.


Subject(s)
Ankle Joint/physiology , Computer Simulation , Electrodes , Models, Biological , Movement/physiology , Electric Stimulation , Feedback, Physiological , Humans , Muscle, Skeletal/physiology , Musculoskeletal Physiological Phenomena , Nonlinear Dynamics , Sciatic Nerve/anatomy & histology , Sciatic Nerve/physiology
17.
Appl Opt ; 53(27): G111-22, 2014 Sep 20.
Article in English | MEDLINE | ID: mdl-25322118

ABSTRACT

The identification and quantification of specific molecules are crucial for studying the pathophysiology of cells, tissues, and organs as well as diagnosis and treatment of diseases. Recent advances in holographic microspectroscopy, based on quantitative phase imaging or optical coherence tomography techniques, show promise for label-free noninvasive optical detection and quantification of specific molecules in living cells and tissues (e.g., hemoglobin protein). To provide important insight into the potential employment of holographic spectroscopy techniques in biological research and for related practical applications, we review the principles of holographic microspectroscopy techniques and highlight recent studies.


Subject(s)
Biopolymers/analysis , Holography/methods , Imaging, Three-Dimensional/methods , Microscopy, Phase-Contrast/methods , Molecular Imaging/methods , Spectrum Analysis/methods , Tomography, Optical Coherence/methods , Technology Assessment, Biomedical
18.
Psychol Rep ; 115(1): 213-27, 2014 Aug.
Article in English | MEDLINE | ID: mdl-25153959

ABSTRACT

The current study was an attempt to examine the interplay between domain-specific self-esteem and life satisfaction with middle-aged Koreans. For four domains (Social/Objective Ability, Positive Characteristics, Interpersonal Relationships, and Family), the mediating effects of the satisfaction index of domain-specific self-esteem between the importance index of domain-specific self-esteem and life satisfaction were tested using structural equation modeling. 364 Koreans in their 40s and 50s were recruited through stratified sampling. Overall, the satisfaction index of domain-specific self-esteem was found to be a strong mediator across all the four domains; for middle-aged Koreans, if they appraised their self-esteem in a given domain as important and they felt satisfied in that domain, their life satisfaction was likely to be higher. Additionally, results of multi-group analysis suggested that the strengths of associations in the model were different between men and women in the Interpersonal Relationships domain.


Subject(s)
Personal Satisfaction , Self Concept , Adult , Age Factors , Female , Humans , Interpersonal Relations , Male , Middle Aged , Republic of Korea/ethnology , Sex Characteristics
19.
ACS Omega ; 9(2): 2519-2527, 2024 Jan 16.
Article in English | MEDLINE | ID: mdl-38250383

ABSTRACT

Furfural is an intermediary toxic aldehyde compound produced during heat-induced food processing and storage. Furfural is also formed by the degradation of cellulosic insulation in oil-immersed electric potential transformers, whose level is an important indicator of aging for replacement. In this study, we report a new means to detect the trace level of furfural in a colorimetric manner. Furfural is reacted with dinitrophenylhydrazine (DNPH) in acid solutions. The colorless furfural-DNPH compound turns orange-colored as the solution changes to basic. The delocalization of the π-electron in the DNPH-aldehyde derivatives at the basic condition causes the shift of the absorption peak from 318 to 470 nm, which renders the solution orange-colored. The color and absorbance are saturated in 20 min of incubation. There is high linearity between the absorbance and the concentration of furfural in the range of 0-0.2 mM, which enables the quantitative detection of furfural. The limit of detection is estimated to be as low as 1.76 µM for the absorbance analysis and 10 µM for the naked eyes. The colorimetric assay protocol is applicable to the detection of various aromatic aldehydes, which show strong π-electron delocalization and is not applicable to aliphatic aldehydes due to lack of delocalization. This simple assay can be conducted in typical 96-well microplates using a microplate reader, which provides a low-cost and high-throughput screening. Therefore, we believe that our method is potentially applicable for the quantitative detection of aromatic aldehydes in various samples from foods, electronic devices, and so on.

20.
Opt Express ; 21(26): 32269-78, 2013 Dec 30.
Article in English | MEDLINE | ID: mdl-24514820

ABSTRACT

3-D refractive index (RI) distribution is an intrinsic bio-marker for the chemical and structural information about biological cells. Here we develop an optical diffraction tomography technique for the real-time reconstruction of 3-D RI distribution, employing sparse angle illumination and a graphic processing unit (GPU) implementation. The execution time for the tomographic reconstruction is 0.21 s for 96(3) voxels, which is 17 times faster than that of a conventional approach. We demonstrated the real-time visualization capability with imaging the dynamics of Brownian motion of an anisotropic colloidal dimer and the dynamic shape change in a red blood cell upon shear flow.


Subject(s)
Cell Tracking/instrumentation , Erythrocytes/cytology , Image Enhancement/instrumentation , Imaging, Three-Dimensional/instrumentation , Refractometry/instrumentation , Tomography, Optical/instrumentation , Algorithms , Cells, Cultured , Computer Systems , Equipment Design , Equipment Failure Analysis , Humans , Image Enhancement/methods , Imaging, Three-Dimensional/methods , Refractometry/methods , Reproducibility of Results , Sensitivity and Specificity , Tomography, Optical/methods
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