MLG

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  • 文章类型: Journal Article
    十二指肠贾第鞭毛虫是世界范围内引起水传播疾病的最常见原因之一。并且通常与环境卫生和卫生条件差的地区的腹泻暴发有关。这项研究旨在评估在设拉子主要公立医院就诊的个体中十二指肠G。伊朗西南部。从2022年8月至2023年5月,共收集了614个来自个体的粪便样本,并使用寄生虫学技术初步检查了十二指肠氏杆菌囊肿。蔗糖浮选,和显微镜。显微镜阳性样品通过寄生虫DNA的SSU-PCR扩增进行验证。多位点基因分型(MLG)方案,专注于磷酸丙糖异构酶(tpi)和谷氨酸脱氢酶(gdh)基因,用于基因分型目的。通过显微镜和SSU-PCR,在7.5%(46/614)和8.5%(52/614)的样品中发现了G.十二指肠囊肿,分别。77.3%(17/22)和45.5%(10/22)的感染样品在tpi和gdh位点获得成功扩增和测序结果,分别。两个基因座的MLG数据仅可用于五个样品。在任何基因位点的22个样本中,54.5%(12/22)被鉴定为组合A,而45.5%(10/22)被确定为组合B。AII是确定的最主要的子组合[54.5%(12/22)],其次是BIII[27%(6/22)],不一致的BIII/BIV[13.6%(3/22)],和BIV[4.5%(1/22)]。在本研究中,没有适合非人类动物宿主的组合(例如,C-F)被检测到。这表明在设拉子中人类贾第鞭毛虫病的传播主要是与人有关的。需要进一步的基于分子的分析来确认和扩展这些发现。这些分析还将有助于确定环境样本中寄生虫的存在和公共卫生重要性,比如喝水。
    Giardia duodenalis is one of the most common causes of waterborne disease worldwide, and is often associated with outbreaks of diarrhea in areas with poor sanitation and hygiene. This study aimed to assess the prevalence and genetic diversity of G. duodenalis assemblages in individuals attending major public hospitals in Shiraz, southwestern Iran. From August 2022 to May 2023, a total of 614 stool samples from individuals were collected and initially examined for G. duodenalis cysts using parasitological techniques, sucrose flotation, and microscopy. Microscopy-positive samples were validated by SSU-PCR amplification of the parasite DNA. A multilocus genotyping (MLG) scheme, which focused on the triose phosphate isomerase (tpi) and the glutamate dehydrogenase (gdh) genes, was employed for genotyping purposes. G. duodenalis cysts were found in 7.5% (46/614) and 8.5% (52/614) of samples through microscopy and SSU-PCR, respectively. Successful amplification and sequencing results were obtained for 77.3% (17/22) and 45.5% (10/22) of the infected samples at the tpi and gdh loci, respectively. MLG data for the two loci were available for only five samples. Out of the 22 samples genotyped at any loci, 54.5% (12/22) were identified as assemblage A, while 45.5% (10/22) were identified as assemblage B. AII was the most predominant sub-assemblage identified [54.5% (12/22)], followed by BIII [27% (6/22)], discordant BIII/BIV [13.6% (3/22)], and BIV [4.5% (1/22)]. In the present study, no assemblages suited for non-human animal hosts (e.g., C-F) were detected. This suggests that the transmission of human giardiasis in Shiraz is primarily anthroponotic. Further molecular-based analyses are necessary to confirm and expand upon these findings. These analyses will also help determine the presence and public health importance of the parasite in environmental samples, such as drinking water.
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  • 文章类型: Journal Article
    已知原核生物产生和分泌范围广泛的具有高功能和结构异质性的生物聚合物。通常在细菌生理学和生态学中负有重要职责。其中,胞外多糖(EPS)在细菌与真核宿主的相互作用中起着相关作用。EPS可以帮助定植宿主并协助细菌生存,通过促进结构化生物膜的形成使这种相互作用更加稳健。此外,它们通常是涉及有益和致病细菌-宿主相互作用的特定识别机制中的关键分子。最近在根瘤菌中发现了一种称为MLG(混合连锁β-葡聚糖)的新型EPS,它参与细菌聚集和生物膜形成,并且是有效附着于豆科植物宿主植物根部所必需的。MLG是第一个,到目前为止,唯一报道的线性混合链β-葡聚糖在细菌中,包含β(1→3)和β(1→4)键的完美交替。对MLG生物合成基因的系统发育研究表明,根瘤菌远非唯一,不同的土壤和植物相关细菌可能产生MLG,将这种新型聚合物添加到大量的表面多糖中,帮助细菌在不断变化的环境中茁壮成长,并与宿主建立成功的相互作用。在这项工作中,提出了一种MLG的量化方法。它通过一种特定的酶(地链酶)对MLG的水解进行中继,以及随后通过苯酚-硫酸方法对释放的二糖(拉米马二糖)进行定量。该协议已经建立并优化了其在96孔板中的使用,这使得它适用于高通量筛选(HTS)方法。这种方法因其快速处理而脱颖而出,技术简单,以及一次处理多个样品和生物重复的能力。
    Prokaryotes are known to produce and secrete a broad range of biopolymers with a high functional and structural heterogeneity, often with critical duties in the bacterial physiology and ecology. Among these, exopolysaccharides (EPS) play relevant roles in the interaction of bacteria with eukaryotic hosts. EPS can help to colonize the host and assist in bacterial survival, making this interaction more robust by facilitating the formation of structured biofilms. In addition, they are often key molecules in the specific recognition mechanisms involved in both beneficial and pathogenic bacteria-host interactions. A novel EPS known as MLG (Mixed-Linkage β-Glucan) was recently discovered in rhizobia, where it participates in bacterial aggregation and biofilm formation and is required for efficient attachment to the roots of their legume host plants. MLG is the first and, so far, the only reported linear Mixed-Linkage β-glucan in bacteria, containing a perfect alternation of β (1 → 3) and β (1 → 4) bonds. A phylogenetic study of MLG biosynthetic genes suggests that far from being exclusive of rhizobia, different soil and plant-associated bacteria likely produce MLG, adding this novel polymer to the plethora of surface polysaccharides that help bacteria thrive in the changing environment and to establish successful interactions with their hosts.In this work, a quantification method for MLG is proposed. It relays on the hydrolysis of MLG by a specific enzyme (lichenase), and the subsequent quantification of the released disaccharide (laminaribiose) by the phenol-sulfuric acid method. The protocol has been set up and optimized for its use in 96-well plates, which makes it suitable for high-throughput screening (HTS) approaches. This method stands out by its fast processing, technical simplicity, and capability to handle multiple samples and biological replicates at a time.
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  • 文章类型: Journal Article
    全球范围内已广泛研究了原生动物病原体十二指肠贾第鞭毛虫的患病率和遗传多样性。目前缺乏有关印度东部生物遗传变异性的数据。了解循环基因型和相关危险因素对于有效计划和实施控制措施至关重要。因此,这项研究的目的是进行流行病学研究,以确定患病率并确定存在的各种基因型。这项调查增加了我们对研究地区贾第虫基因型的发生和分布的了解。总体患病率为6.8%。这种寄生虫感染与两个年龄组显著相关,即,>0-5年和>5-12年。使用多位点基因分型方法,我们对从腹泻患者中获得的52株人贾第鞭毛虫分离株进行了基因分型.在人群中发现了两个不同的组合-30.8%属于组合A;63.5%属于组合B,在人口中普遍存在;5.7%属于A+B组合。在17.3%的病例中发现了次级组合,其次是次级组合人工智能(13.5%)。在进行平衡选择的组合B种群中发现了高水平的遗传多样性。总的来说,观察到的寄生虫的高患病率,特别是在儿童中,引起了人们的重大关切,需要实施强有力的控制措施。此外,我们报告了许多独特的基因型,在这个有限的地理边界中循环,这可能是未来研究的有用数据集。
    The prevalence and genetic diversity of the protozoan pathogen Giardia duodenalis have been extensively studied worldwide. There is currently a lack of data regarding the genetic variability of the organism in eastern India. Understanding the circulating genotypes and associated risk factors is crucial for effective planning and implementing control measures. Therefore, the objective of the study was to conduct an epidemiological study to determine the prevalence and identify the various genotypes present. This survey adds to our knowledge on the occurrence and distribution of Giardia genotypes in the studied region. The overall prevalence was found to be 6.8%. This parasitic infection was significantly associated with two age groups, i.e., >0-5 years and >5-12 years. Using a multilocus genotyping method, we genotyped 52 human Giardia isolates that were obtained from diarrheal patients. Two distinct assemblages were found in the population-30.8% belonged to assemblage A; 63.5% belonged to assemblage B, prevalent in the population; and 5.7% belonged to a combined assemblage A+B. Sub-assemblage AII was found in 17.3% of the cases, followed by sub-assemblage AI (13.5%). High levels of genetic diversity were found within the population of assemblage B undergoing balancing selection. Overall, the high prevalence of the parasite observed, particularly among children, raises a major concern and necessitates implementation of robust control measures. Furthermore, we report the presence of numerous unique genotypes, circulating in this limited geographical boundary, which can be useful dataset for future studies.
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  • 文章类型: Journal Article
    压力传感器迫切需要高性能传感材料的进一步发展。灵敏度和蠕变被认为是评估传感器性能的两个关键指标。对于传感材料的设计和优化,准确估计几个参数对灵敏度和蠕变的影响是至关重要的。在这项研究中,使用响应面方法(RSM)和支持向量回归(SVR)预测灵敏度和蠕变,分别。输入参数是镍(Ni)颗粒的浓度,多壁碳纳米管(MWCNT),和多层石墨烯(MLG),以及磁场强度(B)。根据统计数据,SVR模型表现出更高水平的可预测性和准确性.非支配排序遗传-II算法(NSGA-II)用于生成帕累托最优前沿,并通过决策来确定最终的最优解。在这些条件下,优化结果表明,与早期研究相比,性能有所改善,在0-16kPa的压力范围内,平均灵敏度为0.059kPa-1,蠕变为0.0325,与以前的工作相比,在更宽的范围内显示出更好的灵敏度。理论灵敏度和蠕变与实际值相对相似,经模拟和实验验证,相对偏差分别为0.317%和0.307%。换能器性能优化的未来研究可以利用所提供的方法,因为它是代表性的。
    Pressure sensors urgently need high-performance sensing materials in order to be developed further. Sensitivity and creep are regarded as two key indices for assessing a sensor\'s performance. For the design and optimization of sensing materials, an accurate estimation of the impact of several parameters on sensitivity and creep is essential. In this study, sensitivity and creep were predicted using the response surface methodology (RSM) and support vector regression (SVR), respectively. The input parameters were the concentrations of nickel (Ni) particles, multiwalled carbon nanotubes (MWCNTs), and multilayer graphene (MLG), as well as the magnetic field intensity (B). According to statistical measures, the SVR model exhibited a greater level of predictability and accuracy. The non-dominated sorting genetic-II algorithm (NSGA-II) was used to generate the Pareto-optimal fronts, and decision-making was used to determine the final optimal solution. With these conditions, the optimized results revealed an improved performance compared to the earlier study, with an average sensitivity of 0.059 kPa-1 in the pressure range of 0-16 kPa and a creep of 0.0325, which showed better sensitivity in a wider range compared to previous work. The theoretical sensitivity and creep were relatively similar to the actual values, with relative deviations of 0.317% and 0.307% after simulation and experimental verification. Future research for transducer performance optimization can make use of the provided methodology because it is representative.
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  • 文章类型: Journal Article
    在这次调查中,p-Mg2Si/n-Si异质结光电探测器(PD)是在没有氩气或氮气气氛的情况下通过磁控溅射和低真空退火制造的。首先通过使用悬浮自助转移MLG方法将MLG转移到Mg2Si/Si异质结衬底来制造多层石墨烯(MLG)/Mg2Si/Si异质结PD。在表征相组成之后,Mg2Si/Si和MLG/Mg2Si/Si异质结PDs的形貌和检测性能,证实了Mg2Si/Si和MLG/Mg2Si/Si异质结PD的成功制造,并实现了一些检测能力。与Mg2Si/Si异质结PD比拟,提高了MLG/Mg2Si/Si异质结PD的光吸收和有效分离转移光生载流子的能力。响应度,外量子效率(EQE),噪声等效功率(NEP),探测率(D*),开/关比和其他检测特性得到增强。MLG/Mg2Si/Si异质结PD的峰值响应度和EQE分别为23.7mA/W和2.75%,分别,比以前的1-10mA/W和2.3%更好。结果表明,引入MLG调节Mg2Si/Si异质结PD的检测性能的制备技术是可行的。此外,这项研究揭示了MLG增强光电器件检测性能的潜力,拓宽了Mg2Si/Si基异质结PDs的应用前景,为光电器件的调控提供了方向。
    In this investigation, p-Mg2Si/n-Si heterojunction photodetector (PD) is fabricated by magnetron sputtering and low vacuum annealing in the absence of argon or nitrogen atmosphere. Multilayer Graphene (MLG)/Mg2Si/Si heterojunction PD is first fabricated by transferring MLG to Mg2Si/Si heterojunction substrate using the suspended self-help transfer MLG method. After characterizing the phase composition, morphology and detection properties of Mg2Si/Si and MLG/Mg2Si/Si heterojunction PDs, the successful fabrication of the Mg2Si/Si and MLG/Mg2Si/Si heterojunction PDs are confirmed and some detection capabilities are realized. Compared with the Mg2Si/Si heterojunction PD, the light absorption and the ability to effectively separate and transfer photogenerated carriers of MLG/Mg2Si/Si heterojunction PD are improved. The responsivity, external quantum efficiency (EQE), noise equivalent power (NEP), detectivity (D*), on/off ratio and other detection properties are enhanced. The peak responsivity and EQE of the MLG/Mg2Si/Si heterojunction PD are 23.7 mA/W and 2.75%, respectively, which are better than the previous 1-10 mA/W and 2.3%. The results illustrate that the fabrication technology of introducing MLG to regulate the detection properties of the Mg2Si/Si heterojunction PD is feasible. In addition, this study reveals the potential of MLG to enhance the detection properties of optoelectronic devices, broadens the application prospect of the Mg2Si/Si-based heterojunction PDs and provides a direction for the regulation of optoelectronic devices.
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  • 文章类型: Journal Article
    大麦栽培受到高温胁迫的不利影响,可以调节植物对病原体的防御反应,例如大麦白粉病(Blumeriagraminisf.sp.hordei,Bgh)。早期的研究主要集中在大麦的短期热应激(热休克)对Bgh感染的影响上。在这项研究中,我们的目的是研究短期和长期热胁迫(35°C,30s至5天)对大麦品种Ingrid及其含有不同白粉病抗性基因的近等基因系的Bgh感染的影响(Mla12,Mlg,和mlo5)通过RT-qPCR分析症状严重程度和Bgh生物量。选择的大麦防御基因的表达(BAX抑制剂-1,致病基因相关蛋白-1b,还在先前暴露于热胁迫的植物中监测了呼吸爆发氧化酶同源物F2和热休克蛋白90-1),然后接种了Bgh。我们证明,暴露于短期和长期热应激对所有抗性系的抗性产生负面影响,表现为出现白粉病症状和增加的Bgh生物量。此外,长时间的热应激(48和120小时)增强了易感野生型Ingrid的Bgh症状和生物量。热应激抑制和延迟抗性系中的早期防御基因激活,这是抗性大麦对Bgh部分易感的可能原因。
    Barley cultivation is adversely affected by high-temperature stress, which may modulate plant defense responses to pathogens such as barley powdery mildew (Blumeria graminis f. sp. hordei, Bgh). Earlier research focused mainly on the influence of short-term heat stress (heat shock) of barley on Bgh infection. In this study, our aim was to investigate the effects of both short- and long-term heat stress (35 °C from 30 s to 5 days) on Bgh infection in the barley cultivar Ingrid and its near-isogenic lines containing different powdery mildew resistance genes (Mla12, Mlg, and mlo5) by analyzing symptom severity and Bgh biomass with RT-qPCR. The expression of selected barley defense genes (BAX inhibitor-1, Pathogenesis- related protein-1b, Respiratory burst oxidase homologue F2, and Heat shock protein 90-1) was also monitored in plants previously exposed to heat stress followed by inoculation with Bgh. We demonstrated that pre-exposure to short- and long-term heat stress negatively affects the resistance of all resistant lines manifested by the appearance of powdery mildew symptoms and increased Bgh biomass. Furthermore, prolonged heat stress (48 and 120 h) enhanced both Bgh symptoms and biomass in susceptible wild-type Ingrid. Heat stress suppressed and delayed early defense gene activation in resistant lines, which is a possible reason why resistant barley became partially susceptible to Bgh.
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  • 文章类型: Journal Article
    The glucan content of rice is a key factor defining its nutritional and economic value. Starch and its derivatives have many industrial applications such as in fuel and material production. Non-starch glucans such as (1,3;1,4)-β-D-glucan (mixed-linkage β-glucan, MLG) have many benefits in human health, including lowering cholesterol, boosting the immune system, and modulating the gut microbiome. In this study, the genetic variability of MLG and starch contents were analyzed in rice (Oryza sativa L.) whole grain, by performing a new quantitative analysis of the polysaccharide content of rice grains. The 197 rice accessions investigated had an average MLG content of 252 μg/mg, which was negatively correlated with the grain starch content. A new genome-wide association study revealed seven significant quantitative trait loci (QTLs) associated with the MLG content and two QTLs associated with the starch content in rice whole grain. Novel genes associated with the MLG content were a hexose transporter and anthocyanidin 5,3-O-glucosyltransferase. Also, the novel gene associated with the starch content was a nodulin-like domain. The data pave the way for a better understanding of the genes involved in determining both MLG and starch contents in rice grains and should facilitate future plant breeding programs.
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  • 文章类型: Journal Article
    Plant cell walls (PCWs) form the outer barrier of cells that give the plant strength and directly interact with the environment and other cells in the plant. PCWs are composed of several polysaccharides, of which cellulose forms the main fibrillar network. Enmeshed between these fibrils of cellulose are non-cellulosic polysaccharides (NCPs), pectins, and proteins. This study investigates the sequence, timing, patterning, and architecture of cell wall polysaccharide regeneration in suspension culture cells (SCC) of the grass species Lolium multiflorum (Lolium). Confocal, superresolution, and electron microscopies were used in combination with cytochemical labeling to investigate polysaccharide deposition in SCC after protoplasting. Cellulose was the first polysaccharide observed, followed shortly thereafter by (1,3;1,4)-β-glucan, which is also known as mixed-linkage glucan (MLG), arabinoxylan (AX), and callose. Cellulose formed fibrils with AX and produced a filamentous-like network, whereas MLG formed punctate patches. Using colocalization analysis, cellulose and AX were shown to interact during early stages of wall generation, but this interaction reduced over time as the wall matured. AX and MLG interactions increased slightly over time, but cellulose and MLG were not seen to interact. Callose initially formed patches that were randomly positioned on the protoplast surface. There was no consistency in size or location over time. The architecture observed via superresolution microscopy showed similarities to the biophysical maps produced using atomic force microscopy and can give insight into the role of polysaccharides in PCWs.
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  • 文章类型: Journal Article
    Cell walls of marine macroalgae are composed of diverse polysaccharides that provide abundant carbon sources for marine heterotrophic bacteria. Among them, Zobellia galactanivorans is considered as a model for studying algae-bacteria interactions. The degradation of typical algal polysaccharides, such as agars or alginate, has been intensively studied in this model bacterium, but the catabolism of plant-like polysaccharides is essentially uncharacterized. Here, we identify a polysaccharide utilization locus in the genome of Z. galactanivorans, induced by laminarin (β-1,3-glucans), and containing a putative GH5 subfamily 4 (GH5_4) enzyme, currently annotated as a endoglucanase (ZgEngAGH5_4). A phylogenetic analysis indicates that ZgEngAGH5_4 was laterally acquired from an ancestral Actinobacteria We performed the biochemical and structural characterization of ZgEngAGH5_4 and demonstrated that this GH5 is, in fact, an endo-β-glucanase, most active on mixed-linked glucan (MLG). Although ZgEngAGH5_4 and GH16 lichenases both hydrolyze MLG, these two types of enzymes release different series of oligosaccharides. Structural analyses of ZgEngAGH5_4 reveal that all the amino acid residues involved in the catalytic triad and in the negative glucose-binding subsites are conserved, when compared with the closest relative, the cellulase EngD from Clostridium cellulovorans, and some other GH5s. In contrast, the positive glucose-binding subsites of ZgEngAGH5_4 are different and this could explain the preference for MLG, with respect to cellulose or laminarin. Molecular dynamics computer simulations using different hexaoses reveal that the specificity for MLG occurs through the +1 and +2 subsites of the binding pocket that display the most important differences when compared with the structures of other GH5_4 enzymes.
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  • 文章类型: Journal Article
    Giardia duodenalis (syn. Giardia lamblia, Giardia intestinalis) is an important zoonotic parasite that parasitizes the gastro-intestines of humans and animals, with diarrhea as the most common clinical symptom. The goat has been indicated as one of the most important reservoirs of G. duodenalis for humans. In the present study, we investigated the prevalence and genetic diversity of G. duodenalis in goats in Shaanxi province, northwestern China. A total of 1311 faecal specimens were examined, and the overall prevalence was 7.1% (93/1311). Although all the meat, cashmere and dairy goats were positive for infection, the highest prevalence was found in cashmere goats (10.2%), followed by dairy (9.4%) and meat goats (2.0%). Negative correlation between age and prevalence was also observed, and the highest prevalence was detected in 0-2-month goats. Genetic analysis showed the presence of three assemblages, including two zoonotic (A and B) and one animal-adapted assemblage E, with E as the prevalent assemblage found in all breeds of positive goats. The zoonotic assemblage A was found in Guanzhong dairy and Shanbei cashmere goats, but B was only detected in Boar goats. Additionally, mixed assemblages E and A were also identified in two cashmere goats. Multi-locus genotyping (MLST) using the gene loci of the triosephosphate isomerase (tpi), b-giardin (bg) and glutamate dehydrogenase (gdh) identified four novel multi-locus genotypes (MLGs), including two assemblage E MLGs and two assemblage A MLGs. These results suggested that Boar, Guanzhong dairy and Shanbei cashmere goats in Shaanxi province would be potential reservoirs for human infections in this area, and this study also provided basic data for controlling G. duodenalis infection in goats as well as other hosts.
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