coupling

耦合
  • 文章类型: Journal Article
    在细菌中,染色体复制是通过十几种复制体酶的协调实现的。复制起始蛋白DnaA在复制起点(oriC)熔化DNA双链体并形成复制气泡,然后在装载蛋白DnaC的帮助下装载解旋酶DnaB。然后DnaB解旋酶解开dsDNA并支持DnaG的引发和DNA聚合酶的聚合。DnaB解旋酶用作平台耦合展开,启动,和聚合事件。DnaB解旋酶的多种作用由其独特的结构和动力学构象强调。在这次审查中,我们将讨论DnaB六聚体的组装和各种配偶体结合时的构象变化,DnaB处于封闭扩张(CD)状态,闭合收缩(CC),闭合螺旋(CH),和开放螺旋(OH)进行了讨论。DnaB和合作伙伴之间的这些多重界面是抑制剂设计和新型肽抗生素开发的潜在目标。
    In bacteria, chromosome replication is achieved by the coordinations of more than a dozen replisome enzymes. Replication initiation protein DnaA melts DNA duplex at replication origin (oriC) and forms a replication bubble, followed by loading of helicase DnaB with the help of loader protein DnaC. Then the DnaB helicase unwinds the dsDNA and supports the priming of DnaG and the polymerizing of DNA polymerase. The DnaB helicase functions as a platform coupling unwinding, priming, and polymerizing events. The multiple roles of DnaB helicase are underlined by its distinctive architecture and dynamics conformations. In this review, we will discuss the assembling of DnaB hexamer and the conformational changes upon binding of various partners, DnaB in states of closed dilated (CD), closed constricted (CC), closed helical (CH), and open helical (OH) are discussed. These multiple interfaces among DnaB and partners are potential targets for inhibitors design and novel peptide antibiotics development.
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  • 文章类型: Journal Article
    本研究旨在确定结构变化的模式,函数,早发性和晚发性老年人局灶性癫痫(OFE)的认知能力。这项研究首先利用基于变形的形态计量学分析来识别结构异常,它们被用作种子区域来研究与整个大脑的功能连接。接下来,我们对改变的影像学表现和神经精神病学评估进行了相关性分析.最后,通过中介分析进一步探讨了结构-功能异常在癫痫诊断中的潜在作用.与健康对照组(n=28)相比,结构体积减少的区域集中在双侧小脑,右丘脑,和右中扣带皮质,额叶,temporal,枕叶也在早发性局灶性癫痫中受到影响(n=26),而迟发性患者(n=31)显示小脑,丘脑,扣带萎缩.此外,相关分析提示结构异常与认知评估之间存在关联.小脑的功能连接异常,扣带皮质,额回部分介导结构异常与早发性局灶性癫痫诊断之间的关系。这项研究确定了早发性和晚发性局灶性癫痫的结构和功能异常,并探讨了认知表现的特征。结构-功能耦合可能在癫痫的诊断中起潜在作用。
    This study aimed to determine the patterns of changes in structure, function, and cognitive ability in early-onset and late-onset older adults with focal epilepsy (OFE). This study first utilized the deformation-based morphometry analysis to identify structural abnormalities, which were used as the seed region to investigate the functional connectivity with the whole brain. Next, a correlation analysis was performed between the altered imaging findings and neuropsychiatry assessments. Finally, the potential role of structural-functional abnormalities in the diagnosis of epilepsy was further explored by using mediation analysis. Compared with healthy controls (n = 28), the area of reduced structural volume was concentrated in the bilateral cerebellum, right thalamus, and right middle cingulate cortex, with frontal, temporal, and occipital lobes also affected in early-onset focal epilepsy (n = 26), while late-onset patients (n = 31) displayed cerebellar, thalamic, and cingulate atrophy. Furthermore, correlation analyses suggest an association between structural abnormalities and cognitive assessments. Dysfunctional connectivity in the cerebellum, cingulate cortex, and frontal gyrus partially mediates the relationship between structural abnormalities and the diagnosis of early-onset focal epilepsy. This study identified structural and functional abnormalities in early-onset and late-onset focal epilepsy and explored characters in cognitive performance. Structural-functional coupling may play a potential role in the diagnosis of epilepsy.
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  • 文章类型: Journal Article
    目的:脊髓小脑共济失调3型(SCA3)是一种罕见的遗传性共济失调,影响整个大脑,其特征是影响神经网络的神经退行性疾病。本研究探讨了功能层次结构的变化,连通性,特定脑区的结构变化显著地导致了SCA3患者症状表现的异质性。
    方法:我们前瞻性招募了51名SCA3患者和59名年龄和性别匹配的健康对照。所有参与者都接受了全面的多模态神经影像学和临床评估。在SCA3患者中,我们采用了一种利用静息状态功能连接(FC)梯度的创新方法,来检查小脑和大脑中从感觉运动到模态上区域的分层处理拓扑的非典型模式.还进行了异常FC和大脑中感兴趣区域(ROI)之间的结构连通性的耦合分析,以表征连通性改变。此外,研究了定量ROI值与临床变量之间的关系。
    结果:SCA3患者通过四种不同的计算方法在初级感觉运动至超模态梯度内表现出压缩或扩张,随着FC和结构连通性耦合的中断。在患者中观察到的梯度改变与临床表现之间确定了综合相关性。值得注意的是,改变的部分各向异性值与临床变量没有显着相关。
    结论:SCA3患者小脑和大脑皮质中的异常梯度和连通性可能导致运动到超模态功能的破坏。此外,这些发现支持FCG分析作为诊断SCA3和评估治疗疗效的生物标志物的潜在效用.
    OBJECTIVE: Spinocerebellar Ataxia Type 3 (SCA3) is a rare genetic ataxia that impacts the entire brain and is characterized as a neurodegenerative disorder affecting the neural network. This study explores how alterations in the functional hierarchy, connectivity, and structural changes within specific brain regions significantly contribute to the heterogeneity of symptom manifestations in patients with SCA3.
    METHODS: We prospectively recruited 51 patients with SCA3 and 59 age-and sex-matched healthy controls. All participants underwent comprehensive multimodal neuroimaging and clinical assessments. In SCA3 patients, an innovative approach utilizing gradients in resting-state functional connectivity (FC) was employed to examine atypical patterns of hierarchical processing topology from sensorimotor to supramodal regions in the cerebellum and cerebrum. Coupling analyses of abnormal FC and structural connectivity among regions of interest (ROIs) in the brain were also performed to characterize connectivity alterations. Additionally, relationships between quantitative ROI values and clinical variables were explored.
    RESULTS: Patients with SCA3 exhibited either compression or expansion within the primary sensorimotor-to-supramodal gradient through four distinct calculation methods, along with disruptions in FC and structural connectivity coupling. A comprehensive correlation was identified between the altered gradients and the clinical manifestations observed in patients. Notably, altered fractional anisotropy values were not significantly correlated with clinical variables.
    CONCLUSIONS: Abnormal gradients and connectivity in the cerebellar and cerebral cortices in SCA3 patients may contribute to disrupted motor-to-supramodal functions. Moreover, these findings support the potential utility of FCG analysis as a biomarker for diagnosing SCA3 and assessing treatment efficacy.
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  • 文章类型: Journal Article
    自由基反应在具有官能团的各种分子支架的合成中是强大的。在以前的评论文章中,我们已经提出了1,2-双官能化,远程1,3-,1,4-,1,5-,1,6-和1,7-双官能化,和添加,然后进行环化反应。本文提出的是自由基环化,然后是第二官能化反应。第二官能化可以通过原子转移反应来实现,自由基或过渡金属辅助偶联反应,和中性分子的反应,阳离子和阴离子物种。
    Radical reactions are powerful in the synthesis of diverse molecular scaffolds bearing functional groups. In previous review articles, we have presented 1,2-difunctionalizations, remote 1,3-, 1,4-, 1,5-, 1,6- and 1,7-difunctionalizations, and addition followed by cyclization reactions. Presented in this paper is radical cyclization followed by the second functionalization reaction. The second functionalization could be realized by atom transfer reactions, radical or transition metal-assisted coupling reactions, and reactions with neutral molecules, cationic and anionic species.
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  • 文章类型: Journal Article
    描述物理系统属性演变的时间序列数据的可用性不断提高,促使人们开发了专注于随着时间的推移提取对系统行为的见解的方法。辨别它是来自确定性动力系统还是随机动力系统。替代数据测试通过促进稳健的统计评估在这一过程中起着至关重要的作用。这确保了观察到的结果不仅仅是偶然发生的,但真正反映了底层系统的内在特征。最初的过程包括制定一个零假设,在没有关于基础分布的假设的情况下,使用替代数据进行测试。然后为原始数据和每个代理数据集计算鉴别统计量。原始数据和替代数据集合之间的明显偏差值导致拒绝零假设。在这项工作中,我们提出了各种替代方法,旨在评估随机过程中的特定统计特性。具体来说,我们介绍了评估单个过程中存在自相关性和非线性动力学的方法,使用信息存储作为区分统计数据。此外,引入了检测二元过程中耦合和非线性的方法,为此目的采用互信息率。首先通过涉及表现出线性和非线性动力学的单变量和双变量过程的模拟来测试引入的替代方法。然后,它们适用于在自主和起搏呼吸期间测量的心脏周期(RR间期)和呼吸流量(RESP)变异性的生理时间序列。仿真结果表明,所提出的方法有效地识别了随机系统的基本动力学特征。真实的数据应用表明,节奏呼吸,在低呼吸率下,增加RR和RESP的个体动力学的可预测性,并抑制其耦合动力学中的非线性。
    The increasing availability of time series data depicting the evolution of physical system properties has prompted the development of methods focused on extracting insights into the system behavior over time, discerning whether it stems from deterministic or stochastic dynamical systems. Surrogate data testing plays a crucial role in this process by facilitating robust statistical assessments. This ensures that the observed results are not mere occurrences by chance, but genuinely reflect the inherent characteristics of the underlying system. The initial process involves formulating a null hypothesis, which is tested using surrogate data in cases where assumptions about the underlying distributions are absent. A discriminating statistic is then computed for both the original data and each surrogate data set. Significantly deviating values between the original data and the surrogate data ensemble lead to the rejection of the null hypothesis. In this work, we present various surrogate methods designed to assess specific statistical properties in random processes. Specifically, we introduce methods for evaluating the presence of autodependencies and nonlinear dynamics within individual processes, using Information Storage as a discriminating statistic. Additionally, methods are introduced for detecting coupling and nonlinearities in bivariate processes, employing the Mutual Information Rate for this purpose. The surrogate methods introduced are first tested through simulations involving univariate and bivariate processes exhibiting both linear and nonlinear dynamics. Then, they are applied to physiological time series of Heart Period (RR intervals) and respiratory flow (RESP) variability measured during spontaneous and paced breathing. Simulations demonstrated that the proposed methods effectively identify essential dynamical features of stochastic systems. The real data application showed that paced breathing, at low breathing rate, increases the predictability of the individual dynamics of RR and RESP and dampens nonlinearity in their coupled dynamics.
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  • 文章类型: Journal Article
    旧波纹容器(OCC)制浆废水具有复杂的有机组成和高水平的生物毒性。溶解和胶体物质(DCSs)的存在是纸浆和造纸公司实现封闭水再循环的主要限制因素。为了解决这个问题,本研究采用臭氧催化氧化-生物降解(OCB)耦合法处理OCC制浆废水。使用聚氨酯海绵作为基本骨架,负载纳米TiO2和微生物,分别,然后放入反应器。经过8分钟的臭氧催化氧化反应,进行了10小时的生物反应。该工艺可有效去除OCC纸白水中的COD和BOD5等有机污染物。COD和BOD5的去除率分别为81.5%和85.1%,分别。通过使用聚氨酯海绵构建适合微生物生长和代谢的微环境,本研究成功地应用和优化了工程菌——白色车辙真菌(WRF)——在系统中实现了OCC制浆废水的实际降解。同时,通过考察OCC制浆废水的降解性能,分析了聚氨酯海绵上不同微生物群落的生物相容性。分析了负载在聚氨酯海绵上的微生物群落结构,以了解降解机理和微生物反应行为。白腐真菌(Phanerochaete)对OCC废水的降解贡献更大,并产生了适应OCC废水降解的新菌株。
    Old Corrugated Container (OCC) pulping wastewater has a complex organic composition and high levels of biotoxicity. The presence of dissolved and colloidal substances (DCSs) is a major limiting factor for pulp and paper companies to achieve closed-water recycling. In order to solve this problem, the coupled ozone-catalyzed oxidation and biodegradation (OCB) method was used to treat OCC pulping wastewater in this study. A polyurethane sponge was used as the basic skeleton, loaded with nano TiO2 and microorganisms, respectively, and then put into a reactor. After an 8-min ozone-catalyzed oxidation reaction, a 10-h biological reaction was carried out. The process was effective in removing organic pollutants such as COD and BOD5 from OCC paper whitewater. The removal rates of COD and BOD5 were 81.5% and 85.1%, respectively. By using the polyurethane sponge to construct a microenvironment suitable for microbial growth and metabolism, this study successfully applied and optimized engineered bacteria-white rut fungi (WRF)-in the system to achieve practical degradation of OCC pulping wastewater. Meanwhile, the biocompatibility of different microbial communities on the polyurethane sponge was analyzed by examining the degradation performance of OCC pulping wastewater. The structure of microbial communities loaded on the polyurethane sponge was analyzed to understand the degradation mechanism and microbial reaction behavior. White-rot fungi (Phanerochaete) contributed more to the degradation of OCC wastewater, and new strains adapted to OCC wastewater degradation were generated.
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  • 文章类型: Journal Article
    了解干旱内陆河流域生态系统中碳和水汽通量的动态对于预测和评估气候变化中的区域碳水收支至关重要。然而,旨在揭示干旱地区不断变化的环境中驱动区域碳水收支变化和耦合过程的机制的研究是有限的。这里,我们使用涡流协方差技术分析了上游三个典型生态系统中CO2和H2O通量之间的关系,中间,和中国西北部干旱内陆河流域的下游。我们的结果表明,所有的生态系统都是碳汇,在高山沼泽草地上,农田,和沙漠灌丛分别为-300.2±0.01、-644.8±2.9和-203.7±22.5gCm-2yr-1。在生长季节,空气温度(Ta)主要控制灌溉农田的每日总初级生产力(3GPP)和净生态系统CO2交换(NEE),而土壤温度(Ts)和蒸汽压赤字(VPD)调节了高山沼泽草甸和沙漠灌木丛中的这些参数。此外,Ta和净辐射(Rn)控制了农田的日蒸散量(ET),而Ts和Rn在其他位点调节ET。因此,在生长季节,所有三个生态系统的碳和水蒸气通量往往受到能量限制。上部碳和水蒸气通量的差异响应,中间,这些生态系统的下游与生物物理因素决定了它们在水分利用效率上的不同耦合和变化。值得注意的是,流域下游的荒漠灌木生态系统在碳增益和水损失之间保持了稳定的平衡,表明适应干旱。这项研究为干旱流域生态系统中碳和水蒸气通量变化以及水利用效率变化背后的潜在机制提供了宝贵的见解。
    Understanding the dynamics of carbon and water vapor fluxes in arid inland river basin ecosystems is essential for predicting and assessing the regional carbon-water budget amid climate change. However, studies aiming to unravel the mechanisms driving the variations and coupling process of regional carbon-water budget in a changing environment in arid regions are limited. Here, we used the eddy covariance technique to analyze the relationship between CO2 and H2O fluxes in three typical ecosystems across the upper, middle, and lower reaches of an arid inland river basin in Northwestern China. Our results showed that all ecosystems acted as carbon sinks, with the alpine swamp meadow, cropland, and desert shrubland sequestrating -300.2 ± 0.01, -644.8 ± 2.9, and - 203.7 ± 22.5 g C m-2 yr-1, respectively. Air temperature (Ta) primarily controlled daily gross primary productivity (GPP) and net ecosystem CO2 exchange (NEE) in the irrigated cropland during the growing season, while soil temperature (Ts) and vapor pressure deficit (VPD) regulated these parameters in the alpine swamp meadow and desert shrubland. Additionally, Ta and net radiation (Rn) controlled daily evapotranspiration (ET) in cropland, while Ts and Rn regulated ET at other sites. Consequently, carbon and water vapor fluxes of all three ecosystems tended to be energy-limited during the growing season. The differential responses of carbon and water vapor fluxes in the upper, middle, and lower reaches of these ecosystems to biophysical factors determined their distinct coupling and variations in water use efficiency. Notably, the desert shrub ecosystem in the lower reach of the basin maintained a stable balance between carbon gain and water loss, indicating adaptation to aridity. This study provides valuable insights into the underlying mechanisms behind the changes in carbon and water vapor fluxes and water-use efficiency in arid river basin ecosystems.
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  • 文章类型: Journal Article
    破译土壤中多种元素的生物地球化学耦合可以更好地理解生态系统对外来入侵的稳定性响应。比较了互花米草(Sa)覆盖的湿地土壤中45种元素的耦合与中国沿海地区天然芦苇(Pa)覆盖的土壤中45种元素的耦合。结果表明,互花米草的入侵不仅显著重塑了地球化学的富集和分散状态,但与Pa相比,土壤中多个元素的耦合也解耦。原子质量成为控制多种元素耦合的主要因素,其中原子质量与Pa中的元素耦合之间呈显著正相关,但没有这样的关系被观察到,与较重的耦合相比,较轻的元素更容易受到互花米草入侵的影响,其中的碳,铁(Fe),镉(Cd)的敏感性最高。除了原子质量,生物过程(以土壤有机碳为代表,氮,磷,和硫),海陆之间的相互作用(以盐度和pH值表示),他们的组合解释了17%,10%,多元素耦合的变化为13%,分别。研究表明,互花米草的入侵是驱动滨海湿地土壤多元素循环和协变的重要因素。
    Deciphering the biogeochemical coupling of multiple elements in soils could better mechanistic understanding of ecosystem stability response to the alien invasion. The coupling of 45 elements in soils from wetlands covered by Spartina alterniflora (Sa) was compared with that in soils covered by native Phragmites australis (Pa) in coastal regions of China. Results showed that S. alterniflora invasion not only significantly reshaped geochemical enrichment and dispersion states, but also decoupled the coupling of multiple elements in soils compared with Pa. Atomic mass emerged as the primary factor governing the coupling of multiple elements, of which a significantly positive correlation exhibited between atomic mass with elemental coupling in Pa, but no such relation was observed in SaThe coupling of lighter elements was more susceptible to and generally enhanced by the invasion of S. alterniflora compared to the heavier, of which carbon, iron (Fe), and cadmium (Cd) had the highest susceptibility. Besides atomic mass, biological processes (represented by soil organic carbon, nitrogen, phosphorus, and sulfur), interactions between sea and land (represented by salinity and pH), and their combination explained 17 %, 10 %, and 13 % variation in the coupling of multiple elements, respectively. The present work confirmed that S. alterniflora invasion was the important factor driving soil multi-element cycling and covariation in coastal wetlands.
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  • 文章类型: Journal Article
    背景:磷脂酰肌醇蛋白聚糖-3(GPC3)是一种硫酸乙酰肝素蛋白聚糖(HSPG),通过糖基磷脂酰肌醇(GPI)与细胞膜结合。在健康的成人肝脏中未发现,但在人类肝细胞癌(HCC)中过表达。细胞外囊泡(GPC3+EV)上的蛋白质标记GPC3也可用于HCC检测。然而,缺乏实用且可靠的定量技术来评估EV蛋白,阻碍了其临床应用.
    结果:这里,使用免疫重组酶聚合酶扩增(免疫RPA)过程和成簇的规则间隔短回文重复序列(CRISPR)-Cas13a的双重扩增,我们首先创建了一种免提取的一罐免疫RPA-CRISPR(opiCRISPR),用于直接和极其灵敏的检测EV蛋白。通过RPA扩增EV蛋白靶向检测探针,以生成包含多个CRISPRRNA(crRNA)靶向条形码的长重复序列,并且该信号被CRISPR-Cas13a侧链切割活性进一步放大以产生荧光信号。结果表明,循环细胞外囊泡GPC3(eGPC3)水平是肿瘤中GPC3表达的可靠标志物,为肿瘤诊断开辟了新的途径。
    我们创建了一种基于CRISPR-Cas13a系统的eGPC3检测方法,并成功研究了细胞外囊泡GPC3标志物在肝细胞癌中的意义。
    BACKGROUND: Glypican-3 (GPC3) is a heparan sulfate proteoglycan (HSPG) that binds to the cell membrane via glycosylphosphatidylinositol (GPI). It is not found in healthy adult liver but is overexpressed in human hepatocellular carcinoma (HCC). The protein marker GPC3 on extracellular vesicles (GPC3+ EVs) is also useful for HCC detection. Nevertheless, the absence of practical and dependable quantitative techniques to evaluate EVs proteins prevents their clinical implementation.
    RESULTS: Here, using an immuno-recombinase polymerase amplification (immuno-RPA) process and dual amplification of clustered regularly interspaced short palindromic repeats (CRISPR)-Cas13a, we firstly create an extraction-free one-pot immuno-RPA-CRISPR (opiCRISPR) for the direct and extremely sensitive detection of EVs proteins. The EVs protein-targeted detection probe is amplified by RPA to generate a long repetitive sequence containing multiple CRISPR RNA (crRNA) targeting barcodes, and the signal is further amplified by the CRISPR-Cas13a side-chain cleavage activity to generate a fluorescent signal. The results show that circulating extracellular vesicle GPC3 (eGPC3) levels are a reliable marker for GPC3 expression in tumor, opening up new avenues for tumor diagnosis.
    UNASSIGNED: We created an eGPC3 assay based on the CRISPR-Cas13a system, and successfully study the significance of extracellular vesicle GPC3 markers in hepatocellular carcinoma.
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  • 文章类型: Journal Article
    作为一个理想化的光源,半导体纳米线(NW)激光器由于其在光电子学等许多领域的潜在应用而得到了广泛的研究,纳米光子学,光通信,信号处理,和显示器。在这封信中,我们提出了一种通过在两个交叉接触CdSNW之间形成法布里-珀罗耳语画廊模式(FP-WGM)混合纳米腔来实现单模纳米激光器的新方法,即Xandy-NW.在我们的方法中,x-NW支持在轴方向上的常规FP振荡,而y-NW的横截面提供了具有较高Q因子和模式选择的超小型WGM纳米腔,这证实了可以激发特定的单模。实验上,获得了以517nm为中心的单模激光发射,半峰全宽为0.08nm,激光阈值为约50kWcm-2。建议的设计技能为激光模式调节和单模实现提供了通用策略。耦合NW中的单模低阈值激光策略可以为NW激光器的实际应用开辟新的途径,并进一步在可见范围内触发其他光子器件。
    As an idealized light source, semiconductor nanowire (NW) lasers have been extensively studied due to its potential applications in many fields such as optoelectronics, nanophononics, optical communication, signal processing, and displays. In this letter, we proposed a novel approach to realize a single-mode nanolaser by forming an Fabry-Perot whispering gallery mode (FP-WGM) hybrid nanocavity between two cross-contact CdS NWs, i.e.xandy-NW. In our method,x-NW supports the regular FP oscillation in the axis direction while the cross section ofy-NW provides a ultrasmall WGM nanocavity with a higherQ-factor and mode election which confirms the specific single mode can be excited. Experimentally, single-mode lasing emission centered at 517 nm was obtained with full width at half maximum of 0.08 nm and lasing threshold of ∼50 kW cm-2. The suggested designing skills projected a general strategy for lasing mode regulation and single-mode realization. The single-mode low-threshold lasing strategy in coupled NWs may open a new avenue for practical applications of NW lasers and further trigger other photonic devices at a visible range.
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