SIP

SIP
  • 文章类型: Journal Article
    尽管绿藻莱茵衣藻长期以来一直作为参考生物,很少有研究询问其作为微生物相互作用的主要生产者的作用。这里,我们定量研究了C.reinhardtii的能力,以支持异养微生物使用已建立的共培养系统日本根瘤菌,产生维生素B12的α-变形杆菌。使用稳定的同位素探测和纳米级二次离子质谱(nanoSIMS),我们以单细胞分辨率跟踪了连续和昼夜光照下光合固定碳的流动和随之而来的细菌生物量合成。我们发现,在连续光照下,更多的由藻类固定的13C被细菌细胞吸收,使假设无效,即藻类在夜间发酵降解淀粉储备会促进杂种。15NH4同化率和细胞大小的变化表明,日本M.japonicum细胞减少了与藻类共培养中的新生物量合成,但继续分裂-这是营养限制的标志,通常被称为还原分裂。尽管有这种饥饿的迹象,该细菌仍在合成维生素B12,并支持依赖B12的C.reinhardtii突变体的生长。最后,我们表明,细菌增殖可以完全由共培养中发生的藻类裂解来支持,强调坏死在碳循环中的作用。总的来说,这些结果揭示了这种微生物营养关系中固定碳的稀缺性(特别是在环境相关的光照条件下),即使在细菌饥饿期间也能证明B12交换,并强调了定量方法评估藻类-细菌相互作用中代谢偶联的重要性。
    Although the green alga Chlamydomonas reinhardtii has long served as a reference organism, few studies have interrogated its role as a primary producer in microbial interactions. Here, we quantitatively investigated C. reinhardtii\'s capacity to support a heterotrophic microbe using the established coculture system with Mesorhizobium japonicum, a vitamin B12-producing α-proteobacterium. Using stable isotope probing and nanoscale secondary ion mass spectrometry (nanoSIMS), we tracked the flow of photosynthetic fixed carbon and consequent bacterial biomass synthesis under continuous and diurnal light with single-cell resolution. We found that more 13C fixed by the alga was taken up by bacterial cells under continuous light, invalidating the hypothesis that the alga\'s fermentative degradation of starch reserves during the night would boost M. japonicum heterotrophy. 15NH4 assimilation rates and changes in cell size revealed that M. japonicum cells reduced new biomass synthesis in coculture with the alga but continued to divide-a hallmark of nutrient limitation often referred to as reductive division. Despite this sign of starvation, the bacterium still synthesized vitamin B12 and supported the growth of a B12-dependent C. reinhardtii mutant. Finally, we showed that bacterial proliferation could be supported solely by the algal lysis that occurred in coculture, highlighting the role of necromass in carbon cycling. Collectively, these results reveal the scarcity of fixed carbon in this microbial trophic relationship (particularly under environmentally relevant light regimes), demonstrate B12 exchange even during bacterial starvation, and underscore the importance of quantitative approaches for assessing metabolic coupling in algal-bacterial interactions.
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  • 文章类型: Journal Article
    本文提出了分析,设计,以及针对基于M序列的UWB应用的特定应用AD转换器的低成本实现,以最小化和集成整个UWB传感器系统。因此,本文的主要目标是将AD转换器自己的设计与UWB模拟部分集成到系统级封装(SiP)或直接集成到系统级芯片(SoC)中,不能用商用AD转换器实现,或者会不成比例地昂贵。根据目前使用的UWB传感器系统的要求,为了在拟议的半导体技术中实现最大可能的带宽,本文设计并介绍了一种并联变换器结构。此外,5位和4位并行闪存AD转换器最初被设计为用于特定应用的UWBM序列雷达系统的研究和设计的一部分,并在本文中进行了简要介绍。根据从这些初始设计中获得的知识,建立了新提出的特定UWBM序列系统的要求。在对这些特定UWBM序列系统的早期提出的AD转换器的概念进行全面测试和评估之后,设计了一个新的AD转换器。在根据特定应用的UWBM序列系统的要求确认足够的特性之后,采用AMS低成本0.35µmSiGeBiCMOS技术设计了7位AD转换器,制作,并在本文中介绍。建议的7位AD转换器实现以下参数:ENOB=6.4位,SINAD=38dB,SFDR=42dBc,INL=±2位LSB,DNL=±1.5LSB。最大采样率达到1.4Gs/s,20Ms/s时的功耗为1050mW,在1.4Gs/s时为1290mW,电源为-3.3V。
    The article presents the analysis, design, and low-cost implementation of application-specific AD converters for M-sequence-based UWB applications to minimize and integrate the whole UWB sensor system. Therefore, the main goal of this article is to integrate the AD converter\'s own design with the UWB analog part into the system-in-package (SiP) or directly into the system-on-a-chip (SoC), which cannot be implemented with commercial AD converters, or which would be disproportionately expensive. Based on the current and used UWB sensor system requirements, to achieve the maximum possible bandwidth in the proposed semiconductor technology, a parallel converter structure is designed and presented in this article. Moreover, 5-bit and 4-bit parallel flash AD converters were initially designed as part of the research and design of UWB M-sequence radar systems for specific applications, and are briefly introduced in this article. The requirements of the newly proposed specific UWB M-sequence systems were established based on the knowledge gained from these initial designs. After thorough testing and evaluation of the concept of the early proposed AD converters for these specific UWB M-sequence systems, the design of a new AD converter was initiated. After confirming sufficient characteristics based on the requirements of UWB M-sequence systems for specific applications, a 7-bit AD converter in low-cost 0.35 µm SiGe BiCMOS technology from AMS was designed, fabricated, and presented in this article. The proposed 7-bit AD converter achieves the following parameters: ENOB = 6.4 bits, SINAD = 38 dB, SFDR = 42 dBc, INL = ±2-bit LSB, and DNL = ±1.5 LSB. The maximum sampling rate reaches 1.4 Gs/s, the power consumption at 20 Ms/s is 1050 mW, and at 1.4 Gs/s is 1290 mW, with a power supply of -3.3 V.
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  • 文章类型: Preprint
    虽然绿藻衣藻莱茵一直作为一种参考生物,很少有研究询问其作为微生物相互作用的主要生产者的作用。这里,我们定量研究了C.reinhardtii的能力,以支持异养微生物使用已建立的共培养系统日本根瘤菌,产生维生素B12的α-变形杆菌。使用稳定的同位素探测和纳米级二次离子质谱(nanoSIMS),我们在连续和diel光下以单细胞分辨率跟踪了光合固定碳的流动和随后的细菌生物量合成。我们发现,在连续光照下,藻类固定的13C被细菌细胞吸收,使假设无效,即藻类在夜间发酵降解淀粉储备会促进杂种。15NH4同化率和细胞大小的变化表明,转移的碳不足以使日本M.japonicum细胞平衡生长,而是进行了还原性划分。然而,尽管有这种饥饿的迹象,日本M.仍然支持B12依赖的莱茵hardtii突变体。最后,我们表明,细菌增殖可以完全由共培养中发生的藻类裂解来支持,强调坏死在碳循环中的作用。总的来说,这些结果揭示了这种微生物营养关系中固定碳的稀缺性,即使在细菌饥饿期间也能证明B12交换,并强调了定量方法评估藻类-细菌相互作用中代谢偶联的重要性。
    Although the green alga Chlamydomonas reinhardtii has long served as a reference organism, few studies have interrogated its role as a primary producer in microbial interactions. Here, we quantitatively investigated C. reinhardtii\'s capacity to support a heterotrophic microbe using the established coculture system with Mesorhizobium japonicum , a vitamin B 12 -producing α-proteobacterium. Using stable isotope probing and nanoscale secondary ion mass spectrometry (nanoSIMS), we tracked the flow of photosynthetic fixed carbon and consequent bacterial biomass synthesis under continuous and diurnal light with single-cell resolution. We found that more 13 C fixed by the alga was taken up by bacterial cells under continuous light, invalidating the hypothesis that the alga\'s fermentative degradation of starch reserves during the night would boost M. japonicum heterotrophy. 15 NH 4 assimilation rates and changes in cell size revealed that M. japonicum cells reduced new biomass synthesis in coculture with the alga but continued to divide - a hallmark of nutrient limitation often referred to as reductive division. Despite this sign of starvation, the bacterium still synthesized vitamin B 12 and supported the growth of a B 12 -dependent C. reinhardtii mutant. Finally, we showed that bacterial proliferation could be supported solely by the algal lysis that occurred in coculture, highlighting the role of necromass in carbon cycling. Collectively, these results reveal the scarcity of fixed carbon in this microbial trophic relationship (particularly under environmentally relevant light regimes), demonstrate B 12 exchange even during bacterial starvation, and underscore the importance of quantitative approaches for assessing metabolic coupling in algal-bacterial interactions.
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  • 文章类型: Journal Article
    微生物群落是地下水生态系统的关键参与者。在这个黑暗的环境中,异养微生物依赖于岩石自养生物活动产生的生物量或从表面渗出的有机物的降解。大多数关于地下水生境细菌多样性的研究都是基于16S基因测序和全基因组重建,显示了这些生境中使用的潜在代谢途径。然而,基于分子的研究不允许评估随时间的种群动态或特定化合物的同化及其微生物群落的生化转化。因此,在这项研究中,我们结合了DNA-,磷脂脂肪酸-,和代谢组学稳定的同位素探测,以在Hainich临界区勘探(CZE)的地下水环境中靶向和鉴定异养细菌,重点关注2个具有不同物理化学条件(有氧和缺氧)的含水层。我们使用13C标记的维多酸(木质素衍生的化合物)(单标记)或13CO2和D标记的维多酸的组合(双标记)从4个不同的井中孵育了地下水。我们的结果表明,异养活动主导了所有地下水站点。我们确定了具有分解维多酸的潜力的细菌(狮身人面像或微细菌)。我们观察到有氧和缺氧含水层之间的异养活动差异,表明细菌种群的局部适应。双重标记实验表明,丝氨酸途径是重要的碳同化途径,有机物是新产生的脂质中重要的氢来源。与单标记实验相比,这些实验还产生了不同的标记分类单元,表明地下水生境中存在复杂的相互作用网络。
    Microbial communities are key players in groundwater ecosystems. In this dark environment, heterotrophic microbes rely on biomass produced by the activity of lithoautotrophs or on the degradation of organic matter seeping from the surface. Most studies on bacterial diversity in groundwater habitats are based on 16S gene sequencing and full genome reconstructions showing potential metabolic pathways used in these habitats. However, molecular-based studies do not allow for the assessment of population dynamics over time or the assimilation of specific compounds and their biochemical transformation by microbial communities. Therefore, in this study, we combined DNA-, phospholipid fatty acid-, and metabolomic-stable isotope probing to target and identify heterotrophic bacteria in the groundwater setting of the Hainich Critical Zone Exploratory (CZE), focusing on 2 aquifers with different physico-chemical conditions (oxic and anoxic). We incubated groundwater from 4 different wells using either 13C-labeled veratric acid (a lignin-derived compound) (single labeling) or a combination of 13CO2 and D-labeled veratric acid (dual labeling). Our results show that heterotrophic activities dominate all groundwater sites. We identified bacteria with the potential to break down veratric acid (Sphingobium or Microbacterium). We observed differences in heterotrophic activities between the oxic and anoxic aquifers, indicating local adaptations of bacterial populations. The dual labeling experiments suggested that the serine pathway is an important carbon assimilation pathway and that organic matter was an important source of hydrogen in the newly produced lipids. These experiments also yielded different labeled taxa compared to the single labeling experiments, showing that there exists a complex interaction network in the groundwater habitats.
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  • 文章类型: Journal Article
    所有超宽带(UWB)传感器应用都需要直接为其特定应用而设计的硬件。宽带射频和微波信号的切换几乎是每件高频设备的组成部分,无论是在商业操作或实验室条件。将各种电路结构和系统集成在芯片上(SoC)或单个封装(SiP)中的趋势也与需要为实验室中的各种测量设备和仪器设计这些集成开关有关,矛盾的是他们的进一步发展。另一种可能的用途是在电信设备中切换高频信号,无论是移动网络还是固定网络,例如,用于切换来自多个天线的信号。基于这些要求,设计了一种具有NMOS晶体管的高频半导体集成开关。有了这些晶体管,有可能实现比双极的更高的集成度。即使MOSFET晶体管的频率特性更差,我们可以通过对芯片电路和布局的精确设计在一定程度上补偿它们。本文介绍了由CMOS逻辑信号控制的三个串并联开关组成的用于UWB应用的高频半导体集成开关的分析和设计。它们主要用于UWB传感器系统,例如,当切换和配置天线MIMO系统或切换校准工具时。开关的设计采用低成本的0.35µmSiGeBiCMOS技术实现,重点是尽可能小的衰减以及尽可能大的带宽和隔离。选择该技术的原因还在于该技术实现了UWB系统的其他电路结构。通过模拟,对电路的各个参数进行了仿真,还创建了芯片的布局,并且通过寄生提取和包含寄生元素(布局后仿真)对电路的参数进行了仿真。随后,制作了芯片,并对其参数进行了测量和评估。基于这些测量,发现设计和制造的UWB开关具有以下参数:在3.3V时为2mA的电源电流,6GHz的带宽,插入损耗(1GHz时)为-2.2dB,和隔离(在1GHz)-33dB,满足我们的UWB传感器应用的要求。
    All ultra-wideband (UWB) sensor applications require hardware designed directly for their specific application. The switching of broadband radio frequency and microwave signals is an integral part of almost every piece of high-frequency equipment, whether in commercial operation or laboratory conditions. The trend of integrating various circuit structures and systems on a chip (SoC) or in a single package (SiP) is also related to the need to design these integrated switches for various measuring devices and instruments in laboratories, paradoxically for their further development. Another possible use is switching high-frequency signals in telecommunications devices, whether mobile or fixed networks, for example, for switching signals from several antennas. Based on these requirements, a high-frequency semiconductor integrated switch with NMOS transistors was designed. With these transistors, it is possible to achieve higher integration than with bipolar ones. Even though MOSFET transistors have worse frequency characteristics, we can compensate them to some extent with the precise design of the circuit and layout of the chip. This article describes the analysis and design of a high-frequency semiconductor integrated switch for UWB applications consisting of three series-parallel switches controlled by CMOS logic signals. They are primarily intended for UWB sensor systems, e.g., when switching and configuring the antenna MIMO system or when switching calibration tools. The design of the switch was implemented in low-cost 0.35 µm SiGe BiCMOS technology with an emphasis on the smallest possible attenuation and the largest possible bandwidth and isolation. The reason for choosing this technology was also that other circuit structures of UWB systems were realized in this technology. Through the simulations, individual parameters of the circuit were simulated, the layout of the chip was also created, and the parameters of the circuit were simulated with the parasitic extraction and the inclusion of parasitic elements (post-layout simulations). Subsequently, the chip was manufactured and its parameters were measured and evaluated. Based on these measurements, the designed and fabricated UWB switch was found to have the following parameters: a supply current of 2 mA at 3.3 V, a bandwidth of 6 GHz, an insertion loss (at 1 GHz) of -2.2 dB, and isolation (at 1 GHz) of -33 dB, which satisfy the requirements for our UWB sensor applications.
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  • 文章类型: Journal Article
    目的:对于有症状的不可逆牙髓炎(SIP)的急诊患者,需要对最有效的治疗方法达成更普遍的共识。这项等效随机临床研究比较了临床效率,作为紧急治疗,SIP恒牙的牙髓切除术(POT)和牙髓切除术(PEC)。主要结果是疼痛管理,次要结果是患者对持续时间的感知,comfort,和满意度。
    方法:将80例患者盲目随机分为两个相等的平行组,对照组采用PEC治疗,试验组采用POT治疗。在干预期间以及术后6、24和72h通过数字评分量表(NRS)收集数据。非参数检验用于分析数据。纵向数据采用Brunner-Longer模型,并使用方差分析(ANOVA)型统计学。
    结果:整个样本的术前平均疼痛水平为5.8±2.8,在6h时明显下降至2.1±2.4,24小时1.5±2.1,72h时1.3±2,两组之间没有任何差异。两组患者对治疗不适的感觉或持续时间无显著差异。干预三天后,患者满意度高,PEC和POT组分别为9.2±1.7和9.1±2,分别。自我报告的疼痛是影响患者最终满意度的唯一变量。
    结论:目前的随机对照试验(RCT)表明,牙髓切除术和牙髓切除术均可有效消除疼痛,并获得较高的患者满意度。此外,患者对两种治疗的持续时间和不适的看法相似。鉴于牙髓切除术是一种更快,更直接的技术,建议将其作为治疗有症状的不可逆牙髓炎的急诊患者的可行和实用的选择。
    OBJECTIVE: There needs to be more general agreement on the most effective treatment for the emergency patient with Symptomatic Irreversible Pulpitis (SIP). This equivalence randomised clinical study compared the clinical efficiency, as an urgent treatment, of pulpotomy (POT) and pulpectomy (PEC) in the permanent teeth with SIP. The primary outcome was pain management, and the secondary outcome was the patient\'s perception of duration, comfort, and satisfaction.
    METHODS: 80 patients were blindly and randomly allocated into two equal parallel groups, the control group treated by PEC and the test group by POT. Data were collected through numerical rating scales (NRS) during the intervention and 6, 24, and 72 h post-op. Non-parametric tests were used to analyse the data. The Brunner-Longer models were adopted for longitudinal data and the analysis of variance (ANOVA)-type statistical was used.
    RESULTS: The mean preoperative pain levels for the whole sample scored 5.8 ± 2.8 and significantly decreased to 2.1 ± 2.4 at 6 h, 1.5 ± 2.1 at 24 h, and 1.3 ± 2 at 72 h, without any differences between the groups. No significant differences were found in the patient\'s perception of treatment discomfort or duration between the groups. Three days after the intervention, patient satisfaction was high, with 9.2 ± 1.7 and 9.1 ± 2 in the PEC and POT groups, respectively. Self-reported pain was the only variable penalising the patient\'s final satisfaction.
    CONCLUSIONS: The current randomised control trial (RCT) showed that both pulpectomy and pulpotomy effectively eliminate pain and achieve high levels of patient satisfaction. Furthermore, the patient\'s perceptions of the duration and discomfort of the two treatments were similar. Given that pulpotomy is a faster and more straightforward technique, it may be recommended as a viable and pragmatic option for treating emergency patients with symptomatic irreversible pulpitis.
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  • 文章类型: Video-Audio Media
    背景:将野生微生物的身份与其生态生理特性和环境功能联系起来是微生物生态学家的关键目标。在为这个目标而努力的许多技术中,稳定同位素探测SIP仍然是原位研究整个微生物群落的最全面的方法。在DNA-SIP中,活跃生长的微生物吸收同位素重的底物,构建更重的DNA,可以按密度划分为多个部分并进行测序。然而,SIP的吞吐量相对较低,需要大量的动手劳动。我们设计并测试了一种半自动,高吞吐量SIP(HT-SIP)管道,以支持良好的复制,时间分辨扩增子和宏基因组学实验。我们将此管道应用于具有重要生态意义的土壤微生境-丛枝菌根真菌(AMF)菌丝周围的磷化区。AMF与大多数植物物种形成共生关系,并在陆地养分和碳循环中起关键作用。
    结果:我们的HT-SIP分馏管道,清理,与手动SIP相比,密度梯度的核酸定量需要六分之一的动手劳动,并允许同时处理16个样品。与手动分馏相比,自动密度分馏增加了SIP梯度的可重复性,我们显示向梯度缓冲液中添加非离子去污剂可改善SIPDNA回收率。我们将HT-SIP应用于13CO2植物标记研究中的13C-AMF磷酸化DNA,并使用高分辨率SIP宏基因组学(每个梯度14个宏基因组)创建了宏基因组组装基因组(MAG)。SIP证实AMF根茎内和相关的MAG高度富集(10-33原子%13C),即使土壤的总富集很低(1.8原子%13C)。我们组装了212个13C-hyphosphhereMAG;吸收了大多数AMF衍生的13C的hyphosphhere类群来自门Myxococcota,纤维杆菌,Verrucomicrobiota,和氨氧化古细菌亚硝基属。
    结论:我们的半自动HT-SIP方法通过针对SIP-馏分收集和清理的最劳动密集型步骤,减少了操作时间并提高了可重复性。我们在一种独特且研究不足的土壤微生境生成MAG中说明了这种方法,该MAG活跃地生长在AMFhyphihere中(没有植物根)。MAG的系统发育组成和基因含量表明捕食,分解,氨氧化可能是磷化养分循环的关键过程。视频摘要。
    Linking the identity of wild microbes with their ecophysiological traits and environmental functions is a key ambition for microbial ecologists. Of many techniques that strive for this goal, Stable-isotope probing-SIP-remains among the most comprehensive for studying whole microbial communities in situ. In DNA-SIP, actively growing microorganisms that take up an isotopically heavy substrate build heavier DNA, which can be partitioned by density into multiple fractions and sequenced. However, SIP is relatively low throughput and requires significant hands-on labor. We designed and tested a semi-automated, high-throughput SIP (HT-SIP) pipeline to support well-replicated, temporally resolved amplicon and metagenomics experiments. We applied this pipeline to a soil microhabitat with significant ecological importance-the hyphosphere zone surrounding arbuscular mycorrhizal fungal (AMF) hyphae. AMF form symbiotic relationships with most plant species and play key roles in terrestrial nutrient and carbon cycling.
    Our HT-SIP pipeline for fractionation, cleanup, and nucleic acid quantification of density gradients requires one-sixth of the hands-on labor compared to manual SIP and allows 16 samples to be processed simultaneously. Automated density fractionation increased the reproducibility of SIP gradients compared to manual fractionation, and we show adding a non-ionic detergent to the gradient buffer improved SIP DNA recovery. We applied HT-SIP to 13C-AMF hyphosphere DNA from a 13CO2 plant labeling study and created metagenome-assembled genomes (MAGs) using high-resolution SIP metagenomics (14 metagenomes per gradient). SIP confirmed the AMF Rhizophagus intraradices and associated MAGs were highly enriched (10-33 atom% 13C), even though the soils\' overall enrichment was low (1.8 atom% 13C). We assembled 212 13C-hyphosphere MAGs; the hyphosphere taxa that assimilated the most AMF-derived 13C were from the phyla Myxococcota, Fibrobacterota, Verrucomicrobiota, and the ammonia-oxidizing archaeon genus Nitrososphaera.
    Our semi-automated HT-SIP approach decreases operator time and improves reproducibility by targeting the most labor-intensive steps of SIP-fraction collection and cleanup. We illustrate this approach in a unique and understudied soil microhabitat-generating MAGs of actively growing microbes living in the AMF hyphosphere (without plant roots). The MAGs\' phylogenetic composition and gene content suggest predation, decomposition, and ammonia oxidation may be key processes in hyphosphere nutrient cycling. Video Abstract.
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  • 文章类型: Journal Article
    坏死性筋膜炎是一种严重的传染病,可导致大量死亡。化脓性链球菌(A组链球菌,GAS)是单抗微生物坏死性筋膜炎最常见的细菌病原体之一。坏死性筋膜炎的早期诊断至关重要;然而,典型的皮肤表现并不总是出现在GAS坏死性筋膜炎患者中,会导致诊断失误或延误.在CovR/CovS双组分调节系统中具有自发失活突变的GAS与破坏性疾病如坏死性筋膜炎和中毒性休克综合征显著相关;然而,尚未使用特异性标志物来鉴定这些侵入性临床分离株.这项研究评估了使用CovR/CovS控制的表型鉴定CovR/CovS灭活分离株的敏感性和特异性。结果表明,在CovS灭活的临床分离株中,透明质酸胶囊产量和链球菌溶血素O表达的增加并不一致。SpeB的抑制是在61个临床分离株中的CovS灭活分离株中鉴定具有100%灵敏度的表型。尽管如此,该表型未能将RopB灭活的分离株与CovS灭活的分离株区分开来,也无法用于鉴定CovR灭活的突变体和RocA(Cov的调节因子)灭活的分离株.在这项研究中,我们确认并验证了PepO,通过降解SpeB诱导群体感应肽调节SpeB表达的内肽酶,是一种细菌标记,用于鉴定CovR/CovS途径中存在缺陷的分离株。这些结果还为开发快速检测方法以识别感染期间的侵入性GAS变异的潜在策略提供了信息。重要性坏死性筋膜炎进展迅速,危及生命;如果延迟初步诊断,深部软组织感染可发展为大量组织破坏和中毒性休克综合征。在CovR/CovS双组分调节系统中具有失活突变的A组链球菌(GAS)与坏死性筋膜炎和中毒性休克综合征有关;然而,没有细菌标记可用于鉴定这些侵入性临床分离株.CovR/CovS的失活导致内肽酶PepO的表达增加。我们的研究表明,PepO的上调介导covR突变体中SpeB诱导肽(SIP)的减少,表示CovR/CovS通过PepO调节SIP相关的法定感应活动。重要的是,利用PepO鉴定CovR/CovS途径缺陷的临床分离株的敏感性和特异性,包括其上游的RocA监管机构,是100%。我们的结果表明,通过PepO识别侵入性GAS可能是预防GAS感染后严重表现或预后不良的策略。
    Necrotizing fasciitis is a severe infectious disease that results in significant mortality. Streptococcus pyogenes (group A Streptococcus, GAS) is one of the most common bacterial pathogens of monomicrobial necrotizing fasciitis. The early diagnosis of necrotizing fasciitis is crucial; however, the typical cutaneous manifestations are not always presented in patients with GAS necrotizing fasciitis, which would lead to miss- or delayed diagnosis. GAS with spontaneous inactivating mutations in the CovR/CovS two-component regulatory system is significantly associated with destructive diseases such as necrotizing fasciitis and toxic shock syndrome; however, no specific marker has been used to identify these invasive clinical isolates. This study evaluated the sensitivity and specificity of using CovR/CovS-controlled phenotypes to identify CovR/CovS-inactivated isolates. Results showed that the increase of hyaluronic acid capsule production and streptolysin O expression were not consistently presented in CovS-inactivated clinical isolates. The repression of SpeB is the phenotype with 100% sensitivity of identifying in CovS-inactivated isolates among 61 clinical isolates. Nonetheless, this phenotype failed to distinguish RopB-inactivated isolates from CovS-inactivated isolates and cannot be utilized to identify CovR-inactivated mutant and RocA (Regulator of Cov)-inactivated isolates. In this study, we identified and verified that PepO, the endopeptidase which regulates SpeB expression through degrading SpeB-inducing quorum-sensing peptide, was a bacterial marker to identify isolates with defects in the CovR/CovS pathway. These results also inform the potential strategy of developing rapid detection methods to identify invasive GAS variants during infection. IMPORTANCE Necrotizing fasciitis is rapidly progressive and life-threatening; if the initial diagnosis is delayed, deep soft tissue infection can progress to massive tissue destruction and toxic shock syndrome. Group A Streptococcus (GAS) with inactivated mutations in the CovR/CovS two-component regulatory system are related to necrotizing fasciitis and toxic shock syndrome; however, no bacterial marker is available to identify these invasive clinical isolates. Inactivation of CovR/CovS resulted in the increased expression of endopeptidase PepO. Our study showed that the upregulation of PepO mediates a decrease in SpeB-inducing peptide (SIP) in the covR mutant, indicating that CovR/CovS modulates SIP-dependent quorum-sensing activity through PepO. Importantly, the sensitivity and specificity of utilizing PepO to identify clinical isolates with defects in the CovR/CovS pathway, including its upstream RocA regulator, were 100%. Our results suggest that identification of invasive GAS by PepO may be a strategy for preventing severe manifestation or poor prognosis after GAS infection.
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  • 文章类型: Journal Article
    苏云金芽孢杆菌(Bt)的分泌性杀虫蛋白Sip1Ab和晶体蛋白Cry8Ca因其鞘翅目杀虫活性而受到广泛认可。值得研究这两种蛋白质对ColaphellusbowringiBaly的杀虫机制,在中国和其他亚洲国家是十字花科蔬菜的严重害虫。为此,从QZL38菌株基因组中扩增出编码Sip1Ab和Cry8Ca蛋白的基因,然后在大肠杆菌中表达,之后,在C.bowringi幼虫中进行生物测定。喂食这两种蛋白质后,使用透射电子显微镜(TEM)观察了C.bowringi幼虫中肠的组织病理学变化,并提取刷缘膜囊泡(BBMV)用于竞争结合测定。TEM显示,摄入Sip1Ab导致幼虫的生长显着降低,中肠微绒毛的破坏,和细胞间空间的扩张。竞争结合测定表明Sip1Ab以高结合亲和力结合至C.bowringiBBMV。然而,两种蛋白质等比例的混合物与Sip1Ab的杀虫活性没有显着差异。这些结果为Sip1Ab在鞘翅目昆虫防治中的应用提供了分子基础,也有助于Sip1Ab杀虫机理的研究。
    The secretory insecticidal protein Sip1Ab and crystal protein Cry8Ca from Bacillus thuringiensis (Bt) are widely recognized for their coleopteran insecticidal activities. It is worthwhile to investigate the insecticidal mechanisms of these two proteins against Colaphellus bowringi Baly, which is a serious pest of cruciferous vegetables in China and other Asian countries. To that end, the genes encoding the Sip1Ab and Cry8Ca proteins were amplified from the strain QZL38 genome, then expressed in Escherichia coli, after which bioassays were conducted in C. bowringi larvae. After feeding these two proteins, the histopathological changes in the midguts of C. bowringi larvae were observed using transmission electron microscopy (TEM), and the Brush Border Membrane Vesicle (BBMV) was extracted for competition binding assays. TEM showed that ingestion of Sip1Ab caused a significant reduction in growth of the larvae, disruption of midgut microvilli, and expansion of intercellular spaces. Competition binding assays demonstrated that Sip1Ab bound to C. bowringi BBMV with a high binding affinity. However, a mixture of the two proteins in equal proportions showed no significant difference in insecticidal activity from that of Sip1Ab. These results could provide a molecular basis for the application of Sip1Ab in coleopteran insect control and contribute to the study of the Sip1Ab insecticidal mechanism as well.
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  • 文章类型: Journal Article
    移动通信网络从2G到5G的进步带来了前所未有的流量增长,和5G移动通信网络有望在基于创新技术的各种行业中使用,快速,不仅在极低的延迟方面,而且在海量接入设备方面。各类服务,例如增强型移动宽带(eMBB),大规模机器类型通信(mMTC),和超可靠和低延迟通信(uRLLC),代表对用户个人信息的攻击数量增加,机密信息,和隐私信息。因此,安全评估对于验证和应对这些各种攻击至关重要。在这项研究中,我们(1)查看了5G移动通信网络的背景和问题,以调查存在的漏洞;(2)通过评估实际服务中的5G移动网络的安全威胁来评估当前情况。
    Advances in mobile communication networks from 2G to 5G have brought unprecedented traffic growth, and 5G mobile communication networks are expected to be used in a variety of industries based on innovative technologies, fast not only in terms of extremely low latency but massive access devices. Various types of services, such as enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable and low latency communication (uRLLC), represent an increase in the number of attacks on users\' personal information, confidential information, and privacy information. Therefore, security assessments are essential to verify and cope with these various attacks. In this research, we (1) looked at 5G mobile communication network backgrounds and problems to investigate existing vulnerabilities and (2) assessed the current situation through evaluation of 5G security threats in real-world mobile networks in service.
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