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1.
The correlation between microbiota plays a vital role in the progression of periodontal disease. This study investigated the in situ interaction networks between periodontal pathogens in periodontal and peri-implant disease. We used quantitative real-time polymerase chain reaction and Pearson’s correlation coefficients to quantify the copy numbers and correlations of four oral core species—Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, and Streptococcus gordonii—from 80 subgingival sites (healthy and with periodontitis or gingivitis) in patients with periodontitis, and 68 subgingival sites (healthy and with periodontitis, gingivitis, peri-implantitis, or peri-implant mucositis) in patients with implants. The highest bacterial counts were observed for Porphyromonas gingivalis and Prevotella intermedia at all the sites. Within the same cohorts, the bacterial loads were greater at diseased sites than at healthy sites. Bacterial counts did not differ among clinical sites in the same group (P > 0.05) but differed between periodontitis and peri-implant mucositis sites in the two groups. Porphyromonas gingivalis, F. nucleatum, and Prevotella intermedia had strong correlations at gingivitis and healthy sites and moderate correlations at periodontitis sites in patients with periodontitis. In patients with implants, Prevotella intermedia, F. nucleatum, and S. gordonii had strong correlations only at peri-implantitis sites. Also, based on metagenomic analysis, F. nucleatum and Prevotella intermedia were significantly correlated at the subgingival plaque in peri-implantitis and periodontitis samples. Our results suggest that variations in microbe-microbe interactions in subgingival plaque reflect changes in the progression of periodontal disease, providing a new perspective for understanding the mechanisms of periodontitis and peri-implantitis. 相似文献
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目的:探讨一种目前较为新颖的通过Rotor Gene-3000荧光定量PCR仪进行Tm-shifting荧光定量PCR扩增测定单核苷酸多态性(SNP)的可行性。方法:以913份乳腺肿物患者成纤维细胞生长因子受体2(FGFR2)基因rs2981582位点(T→C)作为研究对象,用荧光染料SYBR GreenI标记DNA,并在设计引物时在所研究基因的特异性引物5’末端连接上不同长度的尾,使不同基因型标本的PCR融解曲线的高峰出现在不同位置,最终可通过对PCR融解曲线的分析进行SNP分型测定。结果:纯合子C/C基因型融解曲线峰出现在≤84.60C处,特殊情况下稍向右偏移,但不超过85.10C,峰型较尖。纯合子T/T基因型融解曲线峰出现在≥87.50C处,特殊情况下稍向左偏移,但不小于870C,峰型较尖。杂合子T/C基因型融解曲线峰出现在前两者之间,峰型较平。结论:实验结果表明,用本方法检测大批量人群标本的SNP结果符合遗传平衡定律,且操作简便,检测耗时短,结果特异且费用较为低廉,适合于进行大规模样品的SNP快速测定。 相似文献
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李树力;李金泽;郭振;朱文艳;周连群;张芷齐 《光学精密工程》2020,28(12):2745-2755
蜂窝状堆叠数字PCR微阵列图像因其单元尺寸小、排列密集,荧光信号弱、易受光照分布影响,其样点定位困难.本文提出基于形态学的三通道蜂窝状荧光图像样点寻址算法及数字PCR图像信息提取方法,可快速、有效识别微阵列芯片生物分子微弱荧光信息.针对不同通道的图像进行配准融合,使样点排布整齐;通过增强图像的对比度,选取有效样点区域,... 相似文献
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Damodaran Arun Mohammad A. Akbarsha Oommen V. Oommen Lekha Divya 《Microscopy research and technique》2019,82(8):1267-1276
Amphibian skin secretions contain a variety of bioactive compounds that are involved in diverse roles such as communication, homeostasis, defence against predators, pathogens, and so on. Especially, the caecilian amphibians possess numerous cutaneous glands that produce the secretory material, which facilitate survival in their harsh subterranean environment. Inspite of the fact that India has a fairly abundant distribution of caecilian amphibians, there has hardly been any study on their skin and its secretion. Herein, we describe, using light microscopy and electron microscopy, two types of dermal glands, mucous and granular, in Gegeneophis ramaswamii. The mucous glands are filled with mucous materials. The mucous‐producing cells are located near the periphery. The granular glands are surrounded by myoepithelial cells. A large number of granules of different sizes are present in the lumen of the granular gland. The granule‐producing cells are present near the myoepithelial lining of the gland. There are small flat disk‐like dermal scales in pockets in the transverse ridges of the posterior region of the body. Each pocket contains 1–4 scales of various sizes. Scanning electron microscopic (SEM) study of the skin surface showed numerous funnel‐shaped glandular openings. The antibacterial activity of the skin secretions was revealed in the test against Escherichia coli, Klebsiella pneumoniae, and Aeromonas hydrophila, all gram‐negative bacteria. SEM analyses confirm the membrane damage in bacterial cells on exposure to skin secretions of G. ramaswamii. 相似文献
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传统PCR(polymerase chain reaction)仪对样品反应池壁温度进行接触式测量与温控,存在测量迟滞大、无法直接控制试剂温度的缺点。研制的电化学实时定量PCR温控系统采用红外温度传感器、热源温度传感器以及环境温度传感器分别测量试剂表面热辐射、热源与反应池壁温度与环境温度,并提出序贯双卡尔曼滤波估计算法对三点温度数据进行信息融合从而估计出试剂表面温度真实值。该算法中迭代卡尔曼滤波器(iterated extended Kalman filter,IEKF)与线性卡尔曼滤波器(Kalman filter,KF)顺序运行,结合了IEKF非线性估计收敛快与KF实时性高的优点,克服了红外测温噪声大,易受环境、被测物热辐射率等因素影响的缺点。试剂温度的估计值作为反馈输入到基于FPAA(field programmable analog array)的可动态配置PID控制器中构成闭环控制,同时微控制器根据不同温控阶段的控制要求对PID控制器进行配置,从而提高温控效率。实验表明,滤波估计后红外测温精度由2℃提高至0.3℃;试剂表面温度监控与可动态配置PID使得PCR温控更加准确高效;PCR产物测试结果优于市面上PCR仪、恒温时间设置更加合理。 相似文献
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时域式PCR生物芯片中温度动力学研究进展 总被引：2，自引：1，他引：2
综述了国内外时域聚合酶链式反应生物芯片中温度动力学研究，包括TD-PCR反应系统加热／冷却速率、温度控制精度、温度均匀性以及热设计的理论模型等。 相似文献
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为了解决高通量数字聚合酶链式反应(dPCR)基因芯片荧光激发问题,设计了一套荧光激发测控系统。系统根据荧光染料的激发光谱特性,选择大功率窄带LED作为荧光激发光源,并通过STM32微处理器系统进行控制。该荧光激发系统有FAM、HEX和ROX三个荧光激发通道,各通道LED激发功率能够分别调节。系统最大输出电流为8 A,单通道最大输出功率为3 W,调节精确度1.0%,系统一次可完成dPCR基因芯片9 600个微液滴的荧光激发和采集。测试实验结果表明,系统达到了设计指标和应用需求。 相似文献
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Qiguo Zhang Jing Wang Hongyan Wu Le Zhang Jinyong Zhou Qing Ye Xiaoyan Shao Chaoyang Guan Jingyan Xu Yonggong Yang Rongfu Zhou Jian Ouyang 《Microscopy research and technique》2010,73(11):1067-1071
Molecular analyses such as fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR) are demanded to improve diagnostic accuracy in addition to immunohistopathology of bone marrow (BM) trephine specimens. Conventional BM embedding method needs decalcification, and its procedure may impair tissue morphology and DNA quality. Here, we report an undecalcified method by which glycol methacrylate resin is polymerized at low temperature (4°C). Using this method, BM enzyme activity and antigenic determinants are well preserved, and moreover, DNA extracted from plastic embedding sections is suitable for PCR amplification and sequencing, FISH analysis can be well done because of the DNA integrity of BM sections. If working with BM trephine specimen, our protocol offers the possibility to combine superior morphology with modern molecular analysis. Microsc. Res. Tech. 73:1067–1071, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
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Fathy Abdel‐Ghaffar Kohar G. Varjabedian Mona Fol Noha Talal Rewaida Abdel‐Gaber Saleh Al Quraishy 《Microscopy research and technique》2020,83(8):901-919
Thirty white‐spotted geckos, Tarentola annularis, from the South Sinai desert in Egypt, were examined for helminth parasites. Spauligodon aspiculus was observed to infect 19 geckos with 63.33% as a prevalence of parasitic infection. The present nematode species is separated from congeners by morphological and metrical characteristics such as lateral alae, aspinose filamentous tail, and no spicule, and three pairs of caudal papillae with posterior pair excluded from envelopment by the caudal alae in the male worms, and knobbed eggs, and postbulbar vulva in females. It compared morphometrically with other Spauligodon species described previously and showed few differences in measurements. Molecular characterization based on the partial 28S rRNA nuclear ribosomal gene sequence showed that there was a close identity, up to 72%, with other sequences retrieved from GenBank. Phylogenetic analysis showed that the parasite sequence in conjunction with existing data facilitates the investigation of the placement of this pharyngodonid species within Oxyuridae. The present species is deeply embedded in the genus Spauligodon with close relationships to previously described Spauligodon nicolauensis (gb| JN619349.1, and JF829243.1) as more related sister taxa. This study highlights the importance of combining genetic and morphological data with taxonomy in pharyngodonid species. 相似文献
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Rafaela Fernandes Zancan Pedro Henrique Souza Calefi Mariana Maciel Batista Borges Marcelo Ribeiro Milanda Lopes Flaviana Bombarda de Andrade Rodrigo Ricci Vivan Marco Antonio Hungaro Duarte 《Microscopy research and technique》2019,82(5):494-500
Enterococcus faecalis and Candida albicans have been associated with cases of secondary and persistent root canal infections, been resistant to calcium hydroxide. So, the evaluation of the susceptibility of these microorganisms biofilms to new drugs is an important practice for establishing the best drug and consequently success of treatment. For this, in vitro biofilm formation of E. faecalis and C. albicans was induced separately on blocks obtained from bovine teeth. After the period of specimen incubation for biofilm maturation, the samples were immersed in the pastes: 1 – calcium hydroxide (CH), 2 – chlorhexidine (C), 3 – ciprofloxacin (CP), 4 – metronidazole (MT), 5 – ketoconazole (KE), 6 – double antibiotic (DB), 7 – triple antibiotic (TA), 8 – ciprofloxacin + ketoconazole (CPKE); 9 – ciprofloxacin + metronidazole + ketoconazole (CPMTKE), 10 – metronidazole + ketoconazole (MTKE), and 11 – control (CO) for 7 days. Next, the specimens were live/dead stained for analysis by confocal microscopy. By means of the Bioimage program, the biovolume and percentage of live cells were measured. The data were statistically compared (p = .05). For the C. albicans biofilm, the best antimicrobial action was found for MTKE, CPKE, and MT groups. Whereas for E. faecalis biofilm, the lowest percentage of live bacteria was found in TA, DB, and CP groups; however, KE, CPKE, CPMTKE, and MTKE groups shown to be effective. The authors concluded calcium hydroxide paste and chlorhexidine was not effective for both biofilms. The MTKE and CPKE pastes presented effectiveness for both biofilms. TA and DB pastes were effective just in the E. faecalis biofilms. 相似文献
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Georg Nawratil 《Mechanism and Machine Theory》2011,46(5):725-742
We use the output angle of a spherical four-bar linkage C as the input angle of a second four-bar linkage D where the two frame links are assumed in aligned position as well as the follower of C and the input link of D. We determine all cases where the relation between the input angle of the input link of C and the output angle of the follower of D is reducible and where additionally at least one of these components produces a transmission which equals that of a single spherical coupler. The problem under consideration is of importance for the classification of flexible 3 × 3 complexes and for the determination of all flexible octahedra in the projective extension of the Euclidean 3-space. 相似文献
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Jiaxin YuShuang Zhang Linmao Qian Jun XuWangyu Ding Zhongrong Zhou 《Tribology International》2011,44(11):1400-1406
With a nanoindenter, the radial nanofretting behaviors of amorphous ultrathin carbon nitride (a-CNx) film on the silicon substrate were investigated by a spherical diamond indenter. The experimental results indicate that the radial nanofretting damage on a-CNx film usually successively experiences the buckling, cracking and detachment of film. These damages can be easily detected by the variation in the apparent contact stiffness. Generally, the initial increase in the contact stiffness indicates the buckling of film; the following sharp decrease in the contact stiffness reveals the initiation and propagation of circular cracks in film; the final stable contact stiffness implies the detachment of film. 相似文献
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Yuanyuan Song Chunhai Zhao Yunyun Zhao Jiaxi Liu 《Microscopy research and technique》2019,82(12):2061-2071
In this paper, we studied pollen morphologies of seven species in genus Aletris in detail by light microscopy and scanning electron microscopy. Of these, six species were reported for the first time. The palynological characteristics do not support the infrageneric classification into two clades. The results indicated that pollen grains of Aletris are small or medium with the P/E ratio of 0.36–0.59. They are elliptic or long‐elliptic in the polar view with blunt, round or acute ends and bilateral symmetric with a monosulcate, narrow or wide, deep colpus that has length extending to the ends of pollen grains, obvious or absent colpus membranes. The pollen ornamentation is gemmate, perforated, or reticulate. The sexine is slightly or quite thicker than the nexine. 相似文献
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We have investigated the surface atomic structure of boundary area of Li- and Na-induced Ge(1 1 1)3×1 reconstruction using scanning tunneling microscope. On Li/Ge(1 1 1)3×1, the 3×1 phase was found to be terminated with a single row in the filled-state image and with dimer-like features in the empty-state image. The images of both interior and boundary of the Li/Ge(1 1 1)3×1 surface are compatible with the honeycomb-chain-channel (HCC) model, which has substrate atoms with double bonds and is well established as the structure of AM/Si(1 1 1)3×1 surfaces. In contrast, termination with zigzag double rows at the domain boundary edges was observed in the filled-state images of the Na/Ge(1 1 1)3×1 phase, which is not reconcilable with the HCC structure. The filled-state STM feature of the boundary region of the Na/Ge(1 1 1)3×1 phase supports a structural model not having Ge=Ge double bonds, which was proposed to interpret its empty-state images. The trend of bondings between atoms in the surface layer of the AM-induced 3×1 reconstruction of Si and Ge is discussed in terms of electronegativity differences. 相似文献
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Previous studies reported that intrageneric relationships of genus Veratrum of family Melanthiaceae are controversial and hard to delimit. Therefore, we observed the pollen morphological features of six species in the genus Veratrum in detail using both light microscopy and scanning electron microscopy and investigated their significance for Veratrum taxonomy. Among them, five were studied for the first time. The results demonstrated that pollen grains of Veratrum are medium in size with P/E being 0.31–0.60. Three types of shape in polar view have been observed elliptic, long‐elliptic, or wide‐elliptic with blunt or rounded at both ends. Two types of width of colpus reported narrow or wide, two types of depth of colpus reported deep or flat, and two types of length of colpus reported extend almost or do not extend to the ends, whereas two types of colpus membranes reported absent or obvious. One type of surface ornamentation was noted as reticulate. These results support species Veratrum album and Veratrum lobelianum as well as Veratrum grandiflorum and Veratrum oxysepalum as two independent species, respectively, rather than classifying Veratrum into two sections. Overall, we demonstrated that the ratio of polar axis length to equatorial axial length, pollen characteristics at the polar view, the colpus morphology, and the surface ornamentation of pollen grains of genus Veratrum have important systematic significance in identification and delimitation of species. 相似文献
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Using light and scanning electron microscopy, we studied the pollen morphology of six species (one of which are endemic) of Chinese Pseudostellaria. All species were studied for the first time. Results of this study indicated that pollen grains of Pseudostellaria are spheroidal or spheroidal‐polyhedral in shape and small or medium in size and pantoporate. Each pollen grain has 12–16 round pores. These pores are apart from each other by 5.77–7.73 μm and each has 7–13 granules in the operculum region. These features have important taxonomic significance. In addition, their pollen grains have thin exine with microechinate‐punctate‐perforate surface ornamentation. Pollen features do not support the traditional infrageneric classification of Pseudostellaria into two sections, but support that Pseudostellaria is closely related to other species of the Odontostemma clade. 相似文献
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Nurcan
. Koakolu Selami Candan Mustafa Güllü 《Microscopy research and technique》2019,82(8):1345-1352
The histomorphology of the reproductive system and the germ cells has been useful to establish phylogenetic relationships in many insects. However, these elements remain little known in the Curculionidae. In this study, histomorphological structure of the male reproductive system of Tanymecus dilaticollis, which is economically important, is described, illustrated using stereomicroscopy, light microscopy, and scanning electron microscopy techniques, and discussed in relation to other Coleoptera species. Results showed that distinctive features of the male reproductive system of T. dilaticollis consist of a pair of yellowish testes, a pair of seminal vesicles, a pair of vasa deferentia, an ejaculatory duct, accessory glands, prostate glands, and aedeagus. Each testis is subdivided into two testicular follicles, enclosed by a peritoneal sheath. Each follicle of the mature testes is full sperm cysts with germ cells at various stages development of spermatogenesis. The testes have four types of germ cells (spermatogonia, spermatocytes, spermatids, and spermatozoa). They are occupied by the growth zone containing spermatogonia and spermatocytes, the maturation zone containing spermatids, while differentiation zone containing spermatozoa. There is a seminal vesicle at the center of each testis. Most mature sperms are stored in the seminal vesicle. Each testis is attached to the vas deferens by a stalk‐like seminal vesicle. In the distal part, vasa deferentia fuse with the ejaculatory duct. It is linked to the aedeagus. The provided results will contribute to the understanding of the reproductive cell biology of Curculionidae. 相似文献
