116 research outputs found

    A DNA 3′ Phosphatase Functions in Active DNA Demethylation in Arabidopsis

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    DNA methylation is an important epigenetic mark established by the combined actions of methylation and demethylation reactions. Plants use a base excision repair pathway for active DNA demethylation. After 5-methylcytosine removal, the Arabidopsis DNA glycosylase/lyase ROS1 incises the DNA backbone and part of the product has a single-nucleotide gap flanked by 3′- and 5′-phosphate termini. Here we show that the DNA phosphatase ZDP removes the blocking 3′ phosphate, allowing subsequent DNA polymerization and ligation steps needed to complete the repair reactions. ZDP and ROS1 interact in vitro and colocalize in vivo in nucleoplasmic foci. Extracts from zdp mutant plants are unable to complete DNA demethylation in vitro, and the mutations cause DNA hypermethylation and transcriptional silencing of a reporter gene. Genome-wide methylation analysis in zdp mutant plants identified hundreds of hypermethylated endogenous loci. Our results show that ZDP functions downstream of ROS1 in one branch of the active DNA demethylation pathway

    Microbial interactions and metabolisms in response to bacterial wilt and black shank pathogens in the tobacco rhizosphere

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    BackgroundTobacco bacterial wilt (TBW) and black shank (TBS) are responsible for substantial economic losses worldwide; however, microbial interactions and metabolisms in response to TBW and TBS pathogens in the tobacco rhizosphere remain unclear.MethodsWe explored and compared the response of rhizosphere microbial communities to these two plant diseases with the incidences in moderate and heavy degrees by sequencing of 16S rRNA gene amplicons and bioinformatics analysis.Results and discussionsWe found that the structure of rhizosphere soil bacterial communities was significantly (p < 0.05) changed from the incidences of TBW and TBS, which also led to decreased Shannon diversity and Pielou evenness. Compared with the healthy group (CK), the OTUs with significantly (p < 0.05) decreased relative abundances were mostly affiliated with Actinobacteria (e.g., Streptomyces and Arthrobacter) in the diseased groups, and the OTUs with significantly (p < 0.05) increased relative abundances were mainly identified as Proteobacteria and Acidobacteria. Also, molecular ecological network analysis showed that the nodes (<467) and links (<641) were decreased in the diseased groups compared with the control group (572; 1056), suggesting that both TBW and TBS weakened bacterial interactions. In addition, the predictive functional analysis indicated that the relative abundance of genes related to the biosynthesis of antibiotics (e.g., ansamycins and streptomycin) was significantly (p < 0.05) decreased due to incidences of TBW and TBS, and antimicrobial tests showed that some Actinobacteria strains (e.g., Streptomyces) and their secreted antibiotics (e.g., streptomycin) could effectively inhibit the growth of these two pathogens

    The First Case of Ischemia-Free Kidney Transplantation in Humans

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    Background: Ischemia-reperfusion injury (IRI) has been considered an inevitable event in organ transplantation since the first successful kidney transplant was performed in 1954. To avoid IRI, we have established a novel procedure called ischemia-free organ transplantation. Here, we describe the first case of ischemia-free kidney transplantation (IFKT). Materials and Methods: The kidney graft was donated by a 19-year-old brain-dead donor. The recipient was a 47-year-old man with end-stage diabetic nephropathy. The graft was procured, preserved, and implanted without cessation of blood supply using normothermic machine perfusion. Results: The graft appearance, perfusion flow, and urine production suggested that the kidney was functioning well-during the whole procedure. The creatinine dropped rapidly to normal range within 3 days post-transplantation. The levels of serum renal injury markers were low post-transplantation. No rejection or vascular or infectious complications occurred. The patient had an uneventful recovery. Conclusion: This paper marks the first case of IFKT in humans. This innovation may offer a unique solution to optimizing transplant outcomes in kidney transplantation

    Emission reduction characteristics of a catalyzed continuously regenerating trap after-treatment system and its durability performance

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    The primary purpose of this study was to investigate the effect of a catalyzed continuously regenerating trap (CCRT) system composed of a diesel oxidation catalyst (DOC) and a catalyzed diesel particulate filter (CDPF) on the main gaseous and particulate emissions from an urban diesel bus, as well as the durability performance of the CCRT system. Experiments were conducted based on a heavy chassis dynamometer, and a laboratory activity test as well as X-ray photoelectron spectroscopy (XPS) test were applied to evaluate the changes of the aged CCRT catalyst. Results showed that the CCRT could reduce the CO by 71.5% and the total hydrocarbons (THC) by 88.9%, and meanwhile promote the oxidation of NO. However, the conversion rates for CO and THC dropped to 25.1% and 55.1%, respectively, after the CCRT was used for one year (~ 60,000 km), and the NO oxidation was also weakened. For particulate emissions, the CCRT could reduce 97.4% of the particle mass (PM) and almost 100% of the particle number (PN). The aging of the CCRT resulted in a reduced PM trapping efficiency but had no observable effect on the PN; however, it increased the proportion of nucleation mode particles. The activity test results indicated that the deterioration of the CCRT was directly relevant to the increase in the light-off temperatures of the catalyst for CO, C3H8 and NO2. In addition, the decreased concentrations of the active components Pt2+ and Pt4+ in the catalyst are also important factors in the CCRT deterioration

    Concept Design of the “Guanlan” Science Mission: China’s Novel Contribution to Space Oceanography

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    Among the various challenges that spaceborne radar observations of the ocean face, the following two issues are probably of a higher priority: inadequate dynamic resolution, and ineffective vertical penetration. It is therefore the vision of the National Laboratory for Marine Science and Technology of China that two highly anticipated breakthroughs in the coming decade are likely to be associated with radar interferometry and ocean lidar (OL) technology, which are expected to make a substantial contribution to a submesoscale-resolving and depth-resolving observation of the ocean. As an expanded follow-up of SWOT and an oceanic counterpart of CALIPSO, the planned “Guanlan” science mission comprises a dual-frequency (Ku and Ka) interferometric altimetry (IA), and a near-nadir pointing OL. Such an unprecedented combination of sensor systems has at least three prominent advantages. (i) The dual-frequency IA ensures a wider swath and a shorter repeat cycle which leads to a significantly improved temporal and spatial resolution up to days and kilometers. (ii) The first spaceborne active OL ensures a deeper penetration depth and an all-time detection which leads to a layered characterization of the optical properties of the subsurface ocean, while also serving as a near-nadir altimeter measuring vertical velocities associated with the divergence, and convergence of geostrophic eddy motions in the mixed layer. (iii) The simultaneous functioning of the IA/OL system allows for an enhanced correction of the contamination effects of the atmosphere and the air-sea interface, which in turn considerably reduces the error budgets of the two sensors. As a result, the integrated IA/OL payload is expected to resolve the ocean variability at submeso and sub-week scales with a centimeter-level accuracy, while also partially revealing marine life systems and ecosystems with a 10-m vertical interval in the euphotic layer, moving a significant step forward toward a “transparent ocean” down to the vicinity of the thermocline, both dynamically and bio-optically

    Identification of Genes and Pathways Associated with Kidney Ischemia-Reperfusion Injury by Bioinformatics Analyses

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    Background/Aims: Ischemia-reperfusion (IR) injury in the kidney is a major cause of acute kidney injury in humans. However, the molecular mechanisms responsible for the progression of kidney IR injury still need to be explored. In this study, we aimed to explore the underlying genes and pathways associated with kidney IR injury. Methods: Gene microarray of GSE27274 was downloaded from the Gene Expression Omnibus database. The differentially expressed genes (DEGs) between kidney IR injury and kidney IR rat samples were analyzed. Gene Ontology biological process (BP) and pathway enrichment analyses of DEGs were performed, followed by protein-protein interaction (PPI) network construction. Results: A total of 88 up-regulated and 102 down-regulated DEGs were identified. The up-regulated DEGs including FK506 binding protein 1A (Fkb1a) were mainly enriched in biological processes (BPs) related to protein ubiquitination. The down-regulated DEGs including complement component 5 (C5) were enriched in complement and coagulation cascades pathway. Choline phosphotransferase 1 (Chpt1) was enriched in glycerophospholipid metabolism pathway. In the PPI network, heme oxygenase (decycling) 1 (Hmox1) was as a hub gene that interacted with the maximum nodes. Conclusions: DEGs of Fkb1a, C5, Chpt1, and Hmox1, as well as complement and coagulation cascades pathway, glycerophospholipid metabolism pathway, and BP terms related to protein ubiquitinatione may be the potential targets for diagnosis and treatment of kidney IR injury

    Effects of ultrasound-guided lumbar plexus and sacral plexus block combined with general anesthesia on the anesthetic efficacy and surgical outcomes in elderly patients undergoing intertrochanteric fracture surgery: a randomized controlled trial

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    Abstract Background Surgery for intertrochanteric fractures in elderly patients is challenging due to the risk of severe pain and significant stress responses. We investigated the effects of a combined approach of ultrasound-guided lumbar plexus and sacral plexus block with general anesthesia on anesthetic efficacy and surgical outcomes in these patients. Methods A randomized controlled trial was conducted involving 150 elderly patients, divided into two groups: the combined anesthesia group (receiving ultrasound-guided lumbar plexus and sacral plexus block along with general anesthesia) and the general anesthesia alone group. Outcome measures included hemodynamic parameters, postoperative pain levels (VAS scores), postoperative recovery times, and incidence of adverse reactions. Results In the combined anesthesia group, the patients had more stable intraoperative hemodynamics, lower postoperative VAS scores at 1, 3, and 6 h, and faster recovery times (eye-opening upon command and return of respiratory function) compared to the general anesthesia group. Furthermore, the incidence of adverse reactions was significantly lower in the combined anesthesia group. Conclusions Ultrasound-guided lumbar plexus and sacral plexus block combined with general anesthesia enhanced the anesthetic efficacy and improved surgical outcomes in elderly patients undergoing intertrochanteric fracture surgery
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