Gotowa bibliografia na temat „NButGT”

Anaphylactic shock (AS) is the most severe form of acute systemic hypersensitivity reaction. Although epinephrine can restore patients’ hemodynamics, it might also be harmful, supporting the need for adjuvant treatment. We therefore investigated whether NButGT, enhancing O-GlcNAcylation and showing beneficial effects in acute heart failure might improve AS therapy. Ovalbumin-sensitized rats were randomly allocated to six groups: control (CON), shock (AS), shock treated with NButGT alone before (AS+pre-Nbut) or after (AS+post-Nbut) AS onset, shock treated with epinephrine alone (AS+EPI) and shock group treated with combination of epinephrine and NButGT (AS+EPI+preNBut). Induction of shock was performed with an intravenous (IV) ovalbumin. Cardiac protein and cycling enzymes O-GlcNAcylation levels, mean arterial pressure (MAP), heart rate, cardiac output (CO), left ventricle shortening fraction (LVSF), mitochondrial respiration, and lactatemia were evaluated using Western blotting experiments, invasive arterial monitoring, echocardiography, mitochondrial oximetry and arterial blood samples. AS decreased MAP (−77%, p < 0.001), CO (−90%, p < 0.001) and LVSF (−30%, p < 0.05). Epinephrine improved these parameters and, in particular, rats did not die in 15 min. But, cardiac mitochondrial respiration remained impaired (complexes I + II −29%, p < 0.05 and II −40%, p < 0.001) with hyperlactatemia. NButGT pretreatment (AS+pre-Nbut) efficiently increased cardiac O-GlcNAcylation level as compared to the AS+post-Nbut group. Compared to epinephrine alone, the adjunction of NButGT significantly improved CO, LVSF and mitochondrial respiration. MAP was not significantly increased but lactatemia decreased more markedly. Pretreatment with NButGT increases O-GlcNAcylation of cardiac proteins and has an additive effect on epinephrine, improving cardiac output and mitochondrial respiration and decreasing blood lactate levels. This new therapy might be useful when the risk of AS cannot be avoided.

The young population, which is particularly at risk of sepsis, is, paradoxically, rarely studied. Acute stimulation of O-GlcNAcylation, a post-translational modification involved in metabolic regulation, cell survival and stress response, is beneficial in young rats with sepsis. Considering that sepsis impacts the gene expression profile and that O-GlcNAcylation is a regulator of transcription, the aims of this study are to (i) unveil beneficial mechanisms of O-GlcNAcylation and (ii) decipher the relationship between O-GlcNAcylation and transcription during sepsis. Endotoxemic challenge was induced in 28-day-old male rats using a lipopolysaccharide injection (E. coli O111:B4, 20 mg·kg−1) and compared to control rats (NaCl 0.9%). One hour after, rats were assigned to no therapy or fluidotherapy (NaCl 0.9%, 10 mL.kg−1) ± NButGT (10 mg·kg−1) to stimulate O-GlcNAc levels. Cardiac O-GlcNAcylation levels were evaluated via Western blot and gene transcription using 3′ SRP analysis. Lipopolysaccharide injection favorizes inflammatory state with the overexpression of genes involved in the NF-κB, JAK/STAT and MAPK pathways. NButGT treatment increased cardiac O-GlcNAcylation levels (p < 0.05). Yet, the mRNA expression was not impacted two hours after fluidotherapy or NButGT treatment. In conclusion, O-GlcNAc stimulation-induced beneficial effects are not dependent on the gene expression profile at the early phase of sepsis.

Sepsis in the young population, which is particularly at risk, is rarely studied. O-GlcNAcylation is a post-translational modification involved in cell survival, stress response and metabolic regulation. O-GlcNAc stimulation is beneficial in adult septic rats. This modification is physiologically higher in the young rat, potentially limiting the therapeutic potential of O-GlcNAc stimulation in young septic rats. The aim is to evaluate whether O-GlcNAc stimulation can improve sepsis outcome in young rats. Endotoxemic challenge was induced in 28-day-old rats by lipopolysaccharide injection (E. Coli O111:B4, 20 mg·kg−1) and compared to control rats (NaCl 0.9%). One hour after lipopolysaccharide injection, rats were randomly assigned to no therapy, fluidotherapy (NaCl 0.9%, 10 mL·kg−1) ± NButGT (10 mg·kg−1) to increase O-GlcNAcylation levels. Physiological parameters and plasmatic markers were evaluated 2h later. Finally, untargeted mass spectrometry was performed to map cardiac O-GlcNAcylated proteins. Lipopolysaccharide injection induced shock with a decrease in mean arterial pressure and alteration of biological parameters (p < 0.05). NButGT, contrary to fluidotherapy, was associated with an improvement of arterial pressure (p < 0.05). ATP citrate lyase was identified among the O-GlcNAcylated proteins. In conclusion, O-GlcNAc stimulation improves outcomes in young septic rats. Interestingly, identified O-GlcNAcylated proteins are mainly involved in cellular metabolism.

We have previously reported that glucosamine protected neonatal rat ventricular myocytes against ischemia-reperfusion (I/R) injury, and this was associated with an increase in protein O-linked- N-acetylglucosamine ( O-GlcNAc) levels. However, the protective effect of glucosamine could be mediated via pathways other that O-GlcNAc formation; thus the initial goal of the present study was to determine whether increasing O-GlcNAc transferase (OGT) expression, which catalyzes the formation of O-GlcNAc, had a protective effect similar to that of glucosamine. To better understand the potential mechanism underlying O-GlcNAc-mediated cytoprotection, we examined whether increased O-GlcNAc levels altered the expression and translocation of members of the Bcl-2 protein family. Both glucosamine (5 mM) and OGT overexpression increased basal and I/R-induced O-GlcNAc levels, significantly decreased cellular injury, and attenuated loss of cytochrome c. Both interventions also attenuated the loss of mitochondrial membrane potential induced by H2O2 and were also associated with an increase in mitochondrial Bcl-2 levels but had no effect on Bad or Bax levels. Compared with glucosamine and OGT overexpression, NButGT (100 μM), an inhibitor of O-GlcNAcase, was less protective against I/R and H2O2 and did not affect Bcl-2 expression, despite a 5- to 10-fold greater increase in overall O-GlcNAc levels. Decreased OGT expression resulted in lower basal O-GlcNAc levels, prevented the I/R-induced increase in O-GlcNAc and mitochondrial Bcl-2, and increased cellular injury. These results demonstrate that the protective effects of glucosamine are mediated via increased formation of O-GlcNAc and suggest that this is due, in part, to enhanced mitochondrial Bcl-2 translocation.

Glycosylation, a dynamic modification prevalent in viruses and higher eukaryotes, is principally regulated by uridine diphosphate (UDP)-glycosyltransferases (UGTs) in plants. Although UGTs are involved in plant defense responses, their responses to most pathogens, especially plant viruses, remain unclear. Here, we aimed to identify UGTs in the whole genome of Nicotiana benthamiana (N. benthamiana) and to analyze their function in Chinese wheat mosaic virus (CWMV) infection. A total of 147 NbUGTs were identified in N. benthamiana. To conduct a phylogenetic analysis, the UGT protein sequences of N. benthamiana and Arabidopsis thaliana were aligned. The gene structure and conserved motifs of the UGTs were also analyzed. Additionally, the physicochemical properties and predictable subcellular localization were examined in detail. Analysis of cis-acting elements in the putative promoter revealed that NbUGTs were involved in temperature, defense, and hormone responses. The expression levels of 20 NbUGTs containing defense-related cis-acting elements were assessed in CWMV-infected N. benthamiana, revealing a significant upregulation of 8 NbUGTs. Subcellular localization analysis of three NbUGTs (NbUGT12, NbUGT16 and NbUGT17) revealed their predominant localization in the cytoplasm of N. benthamiana leaves, and NbUGT12 was also distributed in the chloroplasts. CWMV infection did not alter the subcellular localization of NbUGT12, NbUGT16, and NbUGT17. Transient overexpression of NbUGT12, NbUGT16, and NbUGT17 enhanced CWMV infection, whereas the knockdown of NbUGT12, NbUGT16 and NbUGT17 inhibited CWMV infection in N. benthamiana. These NbUGTs could serve as potential susceptibility genes to facilitate CWMV infection. Overall, the findings throw light on the evolution and function of NbUGTs.

Effective management of fertiliser nitrogen (N) inputs by farmers will generally have beneficial productivity, economic and environmental consequences. The reality is that farmers may be unsure of plant-available N levels in cropping soils at sowing and make decisions about how much fertiliser N to apply with limited information about existing soil N supply. NBudget is a Microsoft (Armonk, NY, USA) Excel-based decision support tool developed primarily to assist farmers and/or advisors in Australia’s northern grains region manage N. NBudget estimates plant-available (nitrate) N at sowing; it also estimates sowing soil water, grain yields, fertiliser N requirements for cereals and oilseed crops and N2 fixation by legumes. NBudget does not rely on soil testing for nitrate-N, organic carbon or soil water content. Rather, the tool relies on precrop (fallow) rainfall data plus basic descriptions of soil texture and fertility, tillage practice and information about paddock use in the previous 2 years. Use is made of rule-of-thumb values and stand-alone or linked algorithms describing, among other things, rates of mineralisation of background soil organic N and fresh residue N. Winter and summer versions of NBudget cover the 10 major crops of the region: bread wheat, durum, barley, canola, chickpea and faba bean in the winter crop version; sorghum, sunflower, soybean and mung bean in the summer crop version. Validating the winter crop version of NBudget estimates of sowing soil nitrate-N against three independent datasets (n=65) indicated generally close agreement between measured and predicted values (y=0.91x+16.8; r2=0.78). A limitation of the tool is that it does not account for losses of N from waterlogged or flooded soils. Although NBudget also predicts grain yields and fertiliser N requirements for the coming season, potential users may simply factor predicted soil N supply into their fertiliser decisions, rather than rely on the output of the tool. Decisions about fertiliser N inputs are often complex and are based on several criteria, including attitudes to risk, history of fertiliser use and costs. The usefulness and likely longevity of NBudget would be enhanced by transforming the current Excel-based tool, currently available on request from the author, to a stand-alone app or web-based tool.

HgS nanoparticles with adjustable dispersibility have been synthesized at the water/n-butyl alcohol interface and characterized with Xray diffraction, transmission electron microscopy. Meanwhile, the dispersibility of the asprepared HgS nanoparticles in water and nbutyl alcohol were measured, respectively. The results indicate that the cubic HgS nanoparticles could be obtained; and the dispersibility of the HgS nanoparticles can be simply tuned. When Hg (CH3COO)2 aqueous solution and nbutyl alcohol solution of thioacetamide are used, the asprepared HgS nanoparticles can be dispersed in water to form a solutionlike suspension. In contrast, when thioacetamide aqueous solution and nbutyl alcohol solution of Hg (CH3COO)2 are used, the oil dispersible HgS nanoparticles are obtained. Moreover, the mechanism about the adjustable dispersibility of HgS nanoparticles is discussed.

AbstractA mixed lithium/beryllium diethylhydroxylaminate compound containing nbutyl beryllium units of total molecular composition nBe(ONEt2)2 [(LiONEt2)2nBuBeONEt2]2 (1) was isolated from a reaction mixture of nbutyl lithium, N,N-diethylhydroxylamine and BeCl2 in diethylether/thf. The crystal structure of 1 has been determined by X-ray diffraction. The aggregate is composed of two ladder-type subunits connected in a beryllium-centered distorted tetrahedron of four oxygen atoms. Only the lithium atoms are engaged in coordination with the nitrogen donor atoms. The DFT calculations support the positional occupation determined for Li and Be in the crystal structure. The DFT and the solid-state structure are in excellent agreement, indicating only weak intermolecular interactions in the solid state. Structural details of metal atom coordination are discussed.

In this paper we study the moment generating function order and the new better than used in the moment generating function order (NBUMG) life distributions. A closure property of this order under an independent random sum is deduced, and stochastic comparisons among the block replacement policy, the age replacement policy, the complete repair policy, and the minimal repair policy of an NBUMG component are investigated.

In this paper we study the moment generating function order and the new better than used in the moment generating function order (NBUMG) life distributions. A closure property of this order under an independent random sum is deduced, and stochastic comparisons among the block replacement policy, the age replacement policy, the complete repair policy, and the minimal repair policy of an NBUMG component are investigated.

Le choc anaphylactique est l’expression clinique la plus sévère de l’anaphylaxie. La sévérité et la rapidité d’installation des signes cliniques sont caractéristiques de cet état de choc. Il est définit par une hypotension artérielle profonde et une dysfonction myocardique. La physiopathologie de cette dysfonction myocardique est encore mal comprise. La mitochondrie pourrait jouer un rôle car nous avons pu observer une dysfonction mitochondriale cardiaque avec une baisse de la respiration mitochondriale et une augmentation de la peroxydation lipidique. La O-N-acetylglucosaminylation (O-GlcNAcylation) est une modification post-traductionnelle ubiquitaire impliquée dans les mécanismes cellulaires protecteurs face à un stress cellulaire aigu. Dans notre modèle de choc anaphylactique, l’augmentation du niveau de O-GlcNAcylation améliore les effets de l’adrénaline sur le myocarde par une augmentation de la contractilité et du débit cardiaque tout en diminuant la lactatémie artérielle, probablement par la restauration de la respiration mitochondriale cardiaque. Avec ces résultats, la dysfonction mitochondriale peut être considérée comme une cause de dysfonction myocardique dans le choc anaphylactique. L’utilisation de traitements adjuvants à l’adrénaline permettrait d’éviter l’apparition d’un choc anaphylactique réfractaire et de limiter les effets adverses de l’adrénaline<br>Anaphylactic shock is the most severe clinical expression of anaphylaxis. The severity and rapidity of clinical signs are characteristic of this state of shock. It is defined by profound arterial hypotension and cardiac dysfunction. The pathophysiology of the cardiac dysfunction is still poorly understood. Mitochondria may play a role, as we have observed cardiac mitochondrial dysfunction with an impairment in mitochondrial respiration and an increase in lipid peroxidation. O-N-acetylglucosaminylation (O-GlcNAcylation) is an ubiquitous post-translational modification involved in the cellular stress response. In our model of anaphylactic shock, increasing the level of O-GlcNAcylation ameliorates the effects of epinephrine on the cardiac function by increasing contractility and cardiac output while decreasing arterial lactataemia, probably by restoring cardiac mitochondrial respiration. With these results, mitochondrial dysfunction can be considered as a cause of myocardial dysfunction in anaphylactic shock. The use of epinephrine adjuvant treatments could prevent the onset of refractory anaphylactic shock and limit the cardiac adverse effects of epinephrine

博士<br>國立中央大學<br>電機工程研究所<br>97<br>To keep pace with progress in fiber communications and the rapid increase in demand for large data capacity it is hoped that radio-over-fiber communication systems will become feasible systems in the future. To do this it is necessary to translate broadband data signals in optical fiber that have low propagation loss and high data capacity without phase delay problems. The final signal is radiated in free space over the last mile to the end user via a photonic transmitter. The system can provide broadband wireless communication services for the user. However, the low frequency bands are too crowded to translate such broadband signals. Thus, it is necessary to select a higher frequency band such as the W band. This however increases the difficulty of designing the optoelectronic mixer and photonic transmitter whose core component is a photodiode. In other words, we need a photodiode with extremely high performance to match the system requirements. Recently a research group at Nippon Telegraph and Telephone Corpration (NTT) has demonstarted a uni-traveling-carrier photodiode (UTC-PD), which minimizes the saturation effect of the traditional pin photodiode, induced by the acumulation of slow photo-generated holes in the absorption region. In this device, the dominant carrier of the saturation phenomenon has been changed from a slow hole carrier to a fast electron carrier, thus greatly improving its speed and saturation power performance. In this study, we demonstrate a new near-ballistic-transport uni-traveling-carrier photodiode (NBUTC-PD) structure, in which the trade-off between the carrier drift velocity and the bias voltage that occurs in traditional UTC-PDs is relaxed. The results indicate that this new structure has superior high bandwidth saturation than the current product. We report and discuss this research in the following manuscript. First, we introduce the design principles and measurement results of the edge-illuminated NBUTC-PD. By inserting an additional p delta-doped layer and an undoped electric-field-buffer layer (E) to the n-doped collector of a traditional UTC-PD, most of the electrical field will cross the E layer. Thus, the electron carrier will drift across the collector layer with an overshoot velocity; only in the thin E layer will it have a saturation drift velocity. By incorporating the structure and the evanescently coupled waveguide, we can not only achieve a high saturation current-bandwidth (>1280mA-GHz, @40GHz), but also high responsivity (1.14A/W). In order to investigate this observed particular bandwidth enhancement phenomenon based on the measurement results, we establish a two port equivalent circuit model which functions according to the measured S parameters and the frequency response. The modeling results suggest that we can attribute the phenomenon to the overshoot drift velocity and the AC reduction capacitance. The established model can not only help us understand the physical characteristics but also provide useful information for the design of other associated components. Then, we demonstrate a back-illuminated NBUTC-PD produced by improving the epi-layer structure and downscaling the active area in order to make it applicable to the W-band ROF system. Because of the overshoot drift velocity, we can further increase the depletion region to reduce the junction capacitance and increase the device speed. By incorporating a microlense, we can improve the device responsivity and alignment tolerance. According to the measurement results, our device can achieve higher speed and saturation current (120GHz, 24.6mA, 2952mA-GHz) than has been reported previously. Then, we discuss how to integrate the device with a band pass filter to serve as an optoelectronic mixer. By taking advantage of the special bias dependence nonlinearity, we can successfully up-convert the intermedium-frequency (IF) signal to 60GHz and 100GHz. The up-conversion loss under different IF and optical local-oscillator (LO) signal powers is also investigated. We found that the filter can reflect the IF power. It forms a standing-wave pattern with a voltage-maximum-peak located around the active device. This phenomenon increases the device nonlinearity and reduces the up-conversion loss. High up-conversion gain (1dB) and large modulation bandwidth (>15GHz) have been observed in our results. Then, we discuss the integration of the device with the planar Yagi antenna to serve as a photonic transmitter. By taking advantage of the special bias dependence nonlinearity, we can up-convert the intermedium-frequency (IF) signal to the W-band through direct modulation. In comparison with that reported previously, not only can we remove the costly optical modulator, and the complex fabrication of the Si lens, but we can also realize the optoelectronic mixer and photonic transmitter in a single devcie. When serving as a photonic mixer under bias modulation operation, the demonstrated device can achieve a -2.4dB internal-conversion-gain at 106GHz while serving as a photonic transmitter we have a maximum detected power at 106GHz of around -14.1dBm with an output photocurrent of 30mA output photocurrent. Finally, we realize 1.25Gbit/s wireless BPSK data transmission bases on this novel device. The measured eye diagram and error vextor magnitude indicates the suitability of the NBTU-PD for application to W-band ROF communication systems.

Abstract Safe and reliable fueling components are essential for large scale deployment of H2 fuel. Field data has shown that existing materials used in dispensing hoses do not meet current standards for component reliability. Currently modern copolymerization methods are under investigation to create a new platform for inner hose technologies using self-healable copolymers. Ideally these inexpensive self-healable copolymer inner layers will reduce the cost of H2 delivery hoses and extend their service life beyond 25,000 refills. In this work gas driven hydrogen permeability measurements were performed on a variety of self-healing copolymer membranes all of which have exhibited excellent self-healing properties in previous studies. Copolymers were prepared with Poly(2,2,2-trifluoroethyl methacrylate/n-butyl acrylate) [p(TFEMA/nBA)] and Poly(methyl methacrylate/nbutyl acrylate) [p(MMA/nBA)]. Measurements were performed through a range of temperatures and source pressures. Additionally, the effects of composition, copolymer ratio, and molecular weight on the hydrogen permeability, solubility, and diffusivity were all studied. As expected, hydrogen permeation through the samples is proportional to the source pressure and inversely proportional to the molecular weight of the polymer. In general, the self-healing copolymers exhibit hydrogen permeabilities consistent with literature data for similar elastomers. These results suggest this class of self-healable copolymers may be promising candidates for use as inexpensive inner layers in hydrogen dispensing hoses with extended service life.