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81.
Real‐time functional optical‐resolution photoacoustic microscopy using high‐speed alternating illumination at 532 and 1064 nm 下载免费PDF全文
Heesung Kang Sang‐Won Lee Sang‐Min Park Soon‐Woo Cho Jae Yong Lee Chang‐Seok Kim Tae Geol Lee 《Journal of biophotonics》2018,11(3)
Optical‐resolution photoacoustic microscopy (OR‐PAM), which has been widely used and studied as a noninvasive and in vivo imaging technique, can yield high‐resolution and absorption contrast images. Recently, metallic nanoparticles and dyes, such as gold nanoparticles, methylene blue, and indocyanine green, have been used as contrast agents of OR‐PAM. This study demonstrates real‐time functional OR‐PAM images with high‐speed alternating illumination at 2 wavelengths. To generate 2 wavelengths, second harmonic generation at 532 nm with an LBO crystal and a pump wavelength of 1064 nm is applied at a pulse repetition rate of 300 kHz. For alternating illumination, an electro‐optical modulator is used as an optical switch. Therefore, the A‐line rate for the functional image is 150 kHz, which is half of the laser repetition rate. To enable fast signal processing and real‐time displays, parallel signal processing using a graphics processing unit (GPU) is performed. OR‐PAM images of the distribution of blood vessels and gold nanorods in a BALB/c‐nude mouse's ear can be simultaneously obtained with 500 × 500 pixels and real‐time display at 0.49 fps. 相似文献
82.
Jun Hyung Seo Hyo Geun Bae Da Hee Park Beom Seok Kim Jong Wook Lee Jung In Lee Dong Hyun Kim Seok Won Lee Bong Bo Seo 《Genes & genomics.》2013,35(1):117-124
Numerous studies on Oenothera species have been investigated for the physiological and ecological characteristics. However, no such an information based on molecular cytogenetic has yet been introduced, in turn, is very essential for identifying sequence polymorphisms of rRNA genes with their loci on mitotic phases for further biological researches. In this study, sequence variations of rRNA genes in Oenothera odorata and O. laciniata were examined to identify informative factors as unique or repeat sequences in intra- and inter-specific variations. Intra-specific variation revealed that the sequences of the rRNA genes including the spacer regions were highly conserved revealing only a few variations. From the inter-specific variation, spacer regions of species were completely different as (1) non-homologous sequences in NTS and (2) different type repeat sequences in ITS 1, 2 and 5.8S rRNA, whereas the remaining coding regions were highly conserved. FISH was carried out on mitotic phases using the 5S rDNA of the analyzed sequences. From the interphase and metaphase chromosomes of the examined species, two loci of 5S rDNA in O. odorata and four loci in O. laciniata were confirmed on the telomeric region of the short arm. Due to the small size and unclear centromere of the chromosomes, karyotype could not be completed. However, we confirmed that the chromosomes are organized by meta- and acrocentric chromosomes and the chromosomes with identified loci were assumed to be paired by the location of loci at the telomeric region on the short arm with relative lengths. 相似文献
83.
Fas/Fas ligand deficiency results in altered localization of anti-double-stranded DNA B cells and dendritic cells 总被引:2,自引:0,他引:2
Fields ML Sokol CL Eaton-Bassiri A Seo S Madaio MP Erikson J 《Journal of immunology (Baltimore, Md. : 1950)》2001,167(4):2370-2378
Autoantibodies directed against dsDNA are found in patients with systemic lupus erythematosus as well as in mice functionally deficient in either Fas or Fas ligand (FasL) (lpr/lpr or gld/gld mice). Previously, an IgH chain transgene has been used to track anti-dsDNA B cells in both nonautoimmune BALB/c mice, in which autoreactive B cells are held in check, and MRL-lpr/lpr mice, in which autoantibodies are produced. In this study, we have isolated the Fas/FasL mutations away from the autoimmune-prone MRL background, and we show that anti-dsDNA B cells in Fas/FasL-deficient BALB/c mice are no longer follicularly excluded, and they produce autoantibodies. Strikingly, this is accompanied by alterations in the frequency and localization of dendritic cells as well as a global increase in CD4 T cell activation. Notably, as opposed to MRL-lpr/lpr mice, BALB-lpr/lpr mice show no appreciable kidney pathology. Thus, while some aspects of autoimmune pathology (e.g., nephritis) rely on the interaction of the MRL background with the lpr mutation, mutations in Fas/FasL alone are sufficient to alter the fate of anti-dsDNA B cells, dendritic cells, and T cells. 相似文献
84.
Transition from Diffusion‐Controlled Intercalation into Extrinsically Pseudocapacitive Charge Storage of MoS2 by Nanoscale Heterostructuring 下载免费PDF全文
Qasim Mahmood Sul Ki Park Kideok D. Kwon Sung‐Jin Chang Jin‐Yong Hong Guozhen Shen Young Mee Jung Tae Jung Park Sung Woon Khang Woo Sik Kim Jing Kong Ho Seok Park 《Liver Transplantation》2016,6(1)
2D nanomaterials have been found to show surface‐dominant phenomena and understanding this behavior is crucial for establishing a relationship between a material's structure and its properties. Here, the transition of molybdenum disulfide (MoS2) from a diffusion‐controlled intercalation to an emergent surface redox capacitive behavior is demonstrated. The ultrafast pseudocapacitive behavior of MoS2 becomes more prominent when the layered MoS2 is downscaled into nanometric sheets and hybridized with reduced graphene oxide (RGO). This extrinsic behavior of the 2D hybrid is promoted by the fast Faradaic charge‐transfer kinetics at the interface. The heterostructure of the 2D hybrid, as observed via high‐angle annular dark field–scanning transmission electron microscopy and Raman mapping, with a 1T MoS2 phase at the interface and a 2H phase in the bulk is associated with the synergizing capacitive performance. This 1T phase is stabilized by the interactions with the RGO. These results provide fundamental insights into the surface effects of 2D hetero‐nanosheets on emergent electrochemical properties. 相似文献
85.
Ju Seok Lee Sungmin Kim Bo-Keun Ha Sungtaeg Kang 《Molecular breeding : new strategies in plant improvement》2016,36(4):50
The amount of ultraviolet-B radiation (UV-B: 280–320 nm) reaching Earth’s surface is expected to increase due to stratospheric ozone depletion. This could cause significant biological damage in plants, and serious yield losses in crops. Soybean [Glycine max (L.) Merr.], a major legume crop, is known to be sensitive to UV-B radiation. Thus, developing a UV-B-tolerant soybean is an efficient and economical strategy to avoid putative yield losses through increased UV-B irradiation. The objective of this study is to identify the novel quantitative trait loci (QTLs) for UV-B tolerance in the soybean using high-density genetic linkage mapping. One hundred and fifteen F8-derived F12 recombinant inbred lines developed from a cross between the UV-B susceptible cultivar, Keunol, and a tolerant breeding line, Iksan 10, were used. Three categories of phenotypic traits were scored: degree of leaf color change, degree of leaf shape change and degree of total plant damage. A genome-wide molecular genetic linkage map containing 8691 single nucleotide polymorphism markers was constructed using the recently developed genotyping platform, the 180K Axiom SoyaSNP assay. Using composite interval mapping analysis, one major candidate QTL on chromosome 7 was identified and designated qUVBT1, and is located between two flanking makers, AX-90437826 and AX-90317546, within 1.6 cM, corresponding to a ~24-kb physical region with six annotated gene models. One of them is a homolog of yeast RAD23, which has previously been reported to be a UV excision repair protein. This result could be valuable in breeding new UV-B-tolerant soybean cultivars and elucidating the UV-B response mechanism in soybean plants. 相似文献
86.
Chang Geun Yoo Hoon Kim Fachuang Lu Ali Azarpira Xuejun Pan Kyeong Keun Oh Jun Seok Kim John Ralph Tae Hyun Kim 《Bioenergy Research》2016,9(1):67-76
Physicochemical characteristics of corn stover pretreated by soaking in aqueous ammonia (SAA) and low-moisture anhydrous ammonia (LMAA) were compared and investigated. The glucan digestibility of the treated biomass reached 90 % (SAA) and 84 % (LMAA). The LMAA pretreatment enhanced the digestibility by cleaving cross-linkages between cell wall components, whereas the SAA pretreatment additionally improved the digestibility by efficiently removing a major portion of the lignin under mild reaction conditions without significant loss of carbohydrates. Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and gel permeation chromatography (GPC) revealed the structural and chemical transformations of lignin during the pretreatments. Both pretreatments effectively cleaved ferulate cell wall cross-linking that is associated with the recalcitrance of grass lignocellulosics toward enzymatic saccharification. Extracted lignin from SAA pretreatment was extensively depolymerized but retained “native” character, as evidenced by the retention of β-ether linkages. 相似文献
87.
Basic and clinical studies have reported that behavioral stress worsens the pathology of Alzheimer disease (AD), but the underlying mechanism has not been clearly understood. In this study, we determined the mechanism by which behavioral stress affects the pathogenesis of AD using Tg-APPswe/PS1dE9 mice, a murine model of AD. Tg-APPswe/PS1dE9 mice that were restrained for 2h daily for 16 consecutive days (2-h/16-day stress) from 6.5months of age had significantly increased Aβ(1-42) levels and plaque deposition in the brain. The 2-h/16-day stress increased oxidative stress and induced mitochondrial dysfunction in the brain. Treatment with glucocorticoid (corticosterone) and Aβ in SH-SY5Y cells increased the expression of 17β-hydroxysteroid dehydrogenase (ABAD), mitochondrial dysfunction, and levels of ROS, whereas blockade of ABAD expression by siRNA-ABAD in SH-SY5Y cells suppressed glucocorticoid-enhanced mitochondrial dysfunction and ROS accumulation. The 2-h/16-day stress up-regulated ABAD expression in mitochondria in the brain of Tg-APPswe/PS1dE9 mice. Moreover, all visible Aβ plaques were costained with anti-ABAD in the brains of Tg-APPswe/PS1dE9 mice. Together, these results suggest that behavioral stress aggravates plaque pathology and mitochondrial dysfunction via up-regulation of ABAD in the brain of a mouse model of AD. 相似文献
88.
The ultrastructural aspects ofCyperus iria leaves showing the C4 syndrome and the typical C3 species,Carex siderosticta, in the Cyperaceae family were examined.C. iria exhibited the chlorocyperoid type, showing an unusual Kranz structure with vascular bundles completely surrounded by two
bundle sheaths. The cellular components of the inner Kranz bundle sheath cells were similar to those found in the NADP-ME
C4 subtype, having centrifugally arranged chloroplasts with greatly reduced grana and numerous starch grains. Their chloroplasts
contained convoluted thyla-koids and a weakly-developed peripheral reticulum, although it was extensive mostly in mesophyll
cell chloroplasts. The outer mestome bundle sheath layer was sclerenchymatous and generally devoid of organelles, but had
unevenly thickened walls. Suberized lamellae were present on its cell walls, and they became polylamellate when traversed
by plasmodesmata. Mesophyll cell chloroplasts showed well-stacked grana with small starch grains. InC. siderosticta, vascular bundles were surrounded by the inner mestome sheath and the outer parenchymatous bundle sheath with intercellular
spaces. The mestome sheath cells degraded in their early development and remained in a collapsed state, although the suberized
lamellae retained polylamellate features. Plastids with a crystalline structure, sometimes membrane-bounded, were found in
the epidermal cells. The close interveinal distance was 35–50 μm inC. iria, whereas it was 157–218 μm inC. siderosticta. These ultrastructural characteristics were discussed in relation to their photosynthetic functions. 相似文献
89.
Han Gil Seo Nam-Jong Paik Shi-Uk Lee Byung-Mo Oh Min Ho Chun Bum Sun Kwon Moon Suk Bang 《PloS one》2015,10(6)
Background
Botulinum toxin type A is widely used for treating spasticity. Neuronox (Neu-BoNT/A), a newly manufactured botulinum toxin a, has not yet been investigated for its efficacy and safety in the treatment of post-stroke upper limb spasticity.Objective
We evaluated the efficacy and safety of Neuronox (Neu-BoNT/A) compared with BOTOX (onabotulinum toxin A) for treating post-stroke upper limb spasticity.Methods
In total, 196 stroke patients with moderate to severe upper limb spasticity were randomly assigned to either Neuronox or BOTOX intervention. The wrist flexors were mandatory and elbow, finger, and thumb flexors were optional muscles to be injected. Assessments were performed at baseline and 4, 8, and 12 weeks after the intervention. The primary outcome measure was the change from baseline of the Modified Ashworth Scale (MAS) at the wrist flexors at week 4. Secondary outcome measures included the change of MAS at each visit, response rate, Disability Assessment Scale (DAS), Carer Burden Scale, and Global Assessment of treatment benefit.Results
Primary outcome measures were -1.39±0.79 and -1.56±0.81 in the Neuronox and BOTOX groups, respectively. The difference was within the noninferiority margin of 0.45 (95% upper limit=0.40). There were no significant differences between the groups in the secondary outcome and safety measures, except the change of the MAS at the elbow flexors at week 12 (-0.88±0.75 in the Neuronox group, -0.65±0.74 in the BOTOX group; P=0.0429). Both groups showed significant improvements in the MAS, DAS, and Carer Burden Scale at weeks 4, 8, and 12.Conclusion
Neuronox showed equivalent efficacy and safety compared with BOTOX for treating post-stroke upper limb spasticity.Trial Registration
ClinicalTrials.gov NCT01313767 相似文献90.
The Arabidopsis RING E3 ubiquitin ligase AtAIRP2 plays combinatory roles with AtAIRP1 in abscisic acid-mediated drought stress responses 总被引:1,自引:0,他引:1
The ubiquitin (Ub)-26S proteasome pathway is implicated in various cellular processes in higher plants. AtAIRP1, a C3H2C3-type RING (for Really Interesting New Gene) E3 Ub ligase, is a positive regulator in the Arabidopsis (Arabidopsis thaliana) abscisic acid (ABA)-dependent drought response. Here, the AtAIRP2 (for Arabidopsis ABA-insensitive RING protein 2) gene was identified and characterized. AtAIRP2 encodes a cytosolic C3HC4-type RING E3 Ub ligase whose expression was markedly induced by ABA and dehydration stress. Thus, AtAIRP2 belongs to a different RING subclass than AtAIRP1 with a limited sequence identity. AtAIRP2-overexpressing transgenic (35S:AtAIRP2-sGFP) and atairp2 loss-of-function mutant plants exhibited hypersensitive and hyposensitive phenotypes, respectively, to ABA in terms of seed germination, root growth, and stomatal movement. 35S:AtAIRP2-sGFP plants were highly tolerant to severe drought stress, and atairp2 alleles were more susceptible to water stress than were wild-type plants. Higher levels of drought-induced hydrogen peroxide production were detected in 35S:AtAIRP2-sGFP as compared with atairp2 plants. ABA-inducible drought-related genes were up-regulated in 35S:AtAIRP2-sGFP and down-regulated in atairp2 progeny. The positive effects of AtAIRP2 on ABA-induced stress genes were dependent on SNF1-related protein kinases, key components of the ABA signaling pathway. Therefore, AtAIRP2 is involved in positive regulation of ABA-dependent drought stress responses. To address the functional relationship between AtAIRP1 and AtAIRP2, FLAG-AtAIRP1 and AtAIRP2-sGFP genes were ectopically expressed in atairp2-2 and atairp1 plants, respectively. Constitutive expression of FLAG-AtAIRP1 and AtAIRP2-sGFP in atairp2-2 and atairp1 plants, respectively, reciprocally rescued the loss-of-function ABA-insensitive phenotypes during germination. Additionally, atairp1/35S:AtAIRP2-sGFP and atairp2-2/35S:FLAG-AtAIRP1 complementation lines were more tolerant to dehydration stress relative to atairp1 and atairp2-2 single knockout plants. Overall, these results suggest that AtAIRP2 plays combinatory roles with AtAIRP1 in Arabidopsis ABA-mediated drought stress responses. 相似文献