96 research outputs found
Blue-Emitting BODIPY Dyes
BODIPY which consists of a dipyrromethene complex with disubstituted boron has emerged as a superior fluorophore in various research fields. BODIPY typically shows high quantum yield with environment-insensitive fluorescence emission, sharp excitation and emission peaks, high water solubility and biocompatibility, and photostability. So far, various kinds of BODIPY derivatives have been developed and applied in not only academia such as chemistry, biochemistry, biomedical engineering, and medicine but also industries. BODIPY shows dramatic photophysical property changes upon substitution of functional groups or pi bond elongation on the main core structure. Among them, the blue-emitting BODIPY dyes with their synthesis and photophysical analysis were recently reported. In this chapter, the key information of the blue-emitting BODIPY dyes and their recent cutting-edge applications are summarized
Extension of Zero Voltage Switching Capability for CLLC Resonant Converter
TheCLLC resonant converter has been widely used to obtaina high power conversion efficiency with sinusoidal current waveforms and a soft switching capability. However, it has a limited voltage gain range according to the input voltage variation. The current-fed structure canbe one solution to extend the voltage gain range for the wide input voltage variation, butit has a limited zero voltage switching (ZVS) range. In this paper, the current-fed CLLC resonant converter with additional inductance is proposed to extend the ZVS range. The operational principle is analyzed to design the additional inductance for obtaining the extended ZVS range. The design methodology of the additional inductance is proposed to maximize the ZVS capability for the entire load range. The performance of the proposed method is verified with a 20 W prototype converter
In vivo two-photon fluorescent imaging of fluoride with a desilylation-based reactive probe
A two-photon excitable molecular probe for fluoride, developed based on a fluoride-specific desilylation reaction, is demonstrated to be useful for fluorescent imaging of fluoride ions in live zebrafish by one-photon as well as two-photon microscopy for the first time.X117778Nsciescopu
Close Correlation of Monoamine Oxidase Activity with Progress of Alzheimer’s Disease in Mice, Observed by in Vivo Two-Photon Imaging
Monoamine oxidases (MAOs) play an important role in Alzheimer's disease (AD) pathology. We report in vivo comonitoring of MAO activity and amyloid-beta (A beta) plaques dependent on the aging of live mice with AD, using a two-photon fluorescence probe. The probe under the catalytic action of MAO produces a dipolar fluorophore that senses A beta plaques, a general AD biomarker, enabling us to comonitor the enzyme activity and the progress of AD indicated by A beta plaques. The results show that the progress of AD has a close correlation with MAO activity, which can be categorized into three stages: slow initiation stage up to three months, an aggressive stage, and a saturation stage from nine months. Histological analysis also reveals elevation of MAO activity around A beta plaques in aged mice. The close correlation between the MAO activity and AD progress observed by in vivo monitoring for the first time prompts us to investigate the enzyme as a potential biomarker of AD.1195Ysciescopu
Mitophagy links oxidative stress conditions and neurodegenerative diseases
Mitophagy is activated by a number of stimuli, including hypoxia, energy stress, and increased oxidative phosphorylation activity. Mitophagy is associated with oxidative stress conditions and central neurodegenerative diseases. Proper regulation of mitophagy is crucial for maintaining homeostasis; conversely, inadequate removal of mitochondria through mitophagy leads to the generation of oxidative species, including reactive oxygen species and reactive nitrogen species, resulting in various neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and amyotrophic lateral sclerosis. These diseases are most prevalent in older adults whose bodies fail to maintain proper mitophagic functions to combat oxidative species. As mitophagy is essential for normal body function, by targeting mitophagic pathways we can improve these disease conditions. The search for effective remedies to treat these disease conditions is an ongoing process, which is why more studies are needed. Additionally, more relevant studies could help establish therapeutic conditions, which are currently in high demand. In this review, we discuss how mitophagy plays a significant role in homeostasis and how its dysregulation causes neurodegeneration. We also discuss how combating oxidative species and targeting mitophagy can help treat these neurodegenerative diseases
Nitrogen Demand Associated with Increased Biomass Yield of Switchgrass and Big Bluestem: Implications for Future Breeding Strategies
Development of perennial biomass cropping systems is focused on maximizing biomass yield with minimum inputs, particularly nitrogen (N) fertilizer. Historical breeding efforts have focused on increasing biomass yield but have ignored N-use efficiency. The purpose of this study was to quantify the increased N demand associated with realized gains in biomass yield from big bluestem (Andropogon gerardii Vitman) and switchgrass (Panicum virgatum L.) breeding programs. Nitrogen demand was highly variable across locations and years, ranging from − 1.7 to + 6.8 kg N Mg−1 DM, with an average of 2.2 kg N Mg−1 DM. Increases in N demand were closely associated with realized gains in biomass yield and were observed for all types of switchgrass (upland, lowland, and hybrid) as well as for big bluestem. Attenuation of these responses will require alternative breeding schemes that are focused on evaluation of switchgrass genotypes and progeny under low-N conditions and include a highthroughput tissue N analysis as a component of future selection criteria, designed to develop new cultivars with high biomass yield and low tissue N
Hypoadiponectinemia and Insulin Resistance are Associated with Nonalcoholic Fatty Liver Disease
We investigated the association between nonalcoholic fatty liver disease (NAFLD) and plasma adiponectin levels and insulin resistance. We recruited study subjects among one hundred and eighty one persons who were examined abdominal ultrasound at routine screening tests. A standard interview (consumption of alcohol and medical history), physical examination (height, weight, waist circumference, and blood pressure), and biochemical study (lipid parameters, aminotransferases, fasting plasma glucose, fasting insulin, and plasma adiponectin) were performed. Subjects who consumed alcohol more than moderate, evidence of viral hepatitis, toxic hepatitis, and serious cardiac, renal, or hepatic disease were excluded. Thirty-eight NAFLD patients and 53 control subjects diagnosed by ultrasound were finally analyzed. The plasma adiponectin level was significantly correlated with HDL-cholesterol (r=0. 38, p<0.001), triglycerides (r=-0.22, p=0.04), fasting insulin (r=-0.37, p<0.01), and insulin resistance by homeostasis model of assessment-insulin resistance (HOMA-IR) (r=-0.39, p<0.01), after adjusting for age, sex, and adiposity. Multiple logistic regression analysis indicated that HOMA-IR was a significant predictor of having NAFLD (odds ratio [OR]=2.38; 95% confidence interval [CI]: 1.52-5.74), while adiponectin had a protective effect against NAFLD (OR=0.22; 95% CI: 0.09-0.55). We demonstrated that hypoadiponectinemia and insulin resistance are associated with NAFLD independent of obesity
The telomere maintenance mechanism spectrum and its dynamics in gliomas
Background : The activation of the telomere maintenance mechanism (TMM) is one of the critical drivers of cancer cell immortality. In gliomas, TERT expression and TERT promoter mutation are considered to reliably indicate telomerase activation, while ATRX mutation and/or loss indicates an alternative lengthening of telomeres (ALT). However, these relationships have not been extensively validated in tumor tissues.
Methods : Telomerase repeated amplification protocol (TRAP) and C-circle assays were used to profile and characterize the TMM cross-sectionally (n = 412) and temporally (n = 133) across glioma samples. WES, RNA-seq, and NanoString analyses were performed to identify and validate the genetic characteristics of the TMM groups.
Results : We show through the direct measurement of telomerase activity and ALT in a large set of glioma samples that the TMM in glioma cannot be defined solely by the combination of telomerase activity and ALT, regardless of TERT expression, TERT promoter mutation, and ATRX loss. Moreover, we observed that a considerable proportion of gliomas lacked both telomerase activity and ALT. This telomerase activation-negative and ALT negative group exhibited evidence of slow growth potential. By analyzing a set of longitudinal samples from a separate cohort of glioma patients, we discovered that the TMM is not fixed and can change with glioma progression.
Conclusions : This study suggests that the TMM is dynamic and reflects the plasticity and oncogenicity of tumor cells. Direct measurement of telomerase enzyme activity and evidence of ALT should be considered when defining TMM. An accurate understanding of the TMM in glioma is expected to provide important information for establishing cancer management strategies.This research was supported by the Bio & Medical Technology Development Program of the National Research Foundation (NRF), funded by the Ministry of Science & ICT (NRF-2018M3A9H3021707), and the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (HI21C0239)
DIFFERENTIAL GERSTENHABER-BATALIN-VILKOVISKY ALGEBRAS FOR CALABI-YAU HYPERSURFACE COMPLEMENTS
Barannikov and Kontsevich [Frobenius manifolds and formality of Lie algebras of polyvector fields. Int. Math. Res. Not. IMRN 1998(4) (1998), 201215], constructed a DGBV (differential Gerstenhaber-Batalin-ovisky) algebra t for a compact smooth Calabi-Yau complex manifold M of dimension m, which gives rise to the B-side formal Frobenius manifold structure in the homological mirror symmetry conjecture. The cohomology of the DGBV algebra t is isomorphic to the total singular cohomology H-center dot (M) = circle plus(2m)(k=0) H-k (M,C) of M. if M = X-G (C), where X-G is the hypersurface defined by a homogeneous polynomial G((x) under bar) in the projective space P-n, then we give a purely algorithmic construction of a DGBV algebra A(U) , which computes the primitive part circle plus(m)(k=0) PHk of the middle-dimensional cohomology circle plus(m)(k=0) H-k (M,C) using the de Rham cohomology of the hypersurface complement U-G := P-n \ X-G and the residue isomorphism from H-dR(k) (U-G / C) to PHk. We observe that the DGBV algebra A(U) still makes sense even for a singular projective Calabi-Yau hypersurface, i.e. A(U) computes circle plus(m)(k=0) H-dR(k) (U-G/C) even for a singular X-G. Moreover, we give a precise relationship between A(U) and and t when X-G is smooth in P-n.11Nsciescopu
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