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  • Morphological evolution of HAZ microstructures in low carbon steel during simulated welding thermal cycle
    Micron (IF 1.53) Pub Date : 2020-01-15
    Liangyun Lan; Guoqing Shao

    It is necessary to reveal the derivation of bainite microstructures with different appearance because these complex appearances are closely related to the transformation nature and their final mechanical properties. In this work, the morphological evolution of HAZ microstructures during simulated welding thermal cycle was investigated in a low carbon steel that was intentionally treated with combined addition of Ti and Mg elements. The inclusions present in the matrix have a complex core/shell composite structure composed of Al-Ca-Mg-Ti-O and MnS. However, only very few inclusions with large size (about 2∼6μm) can stimulate the intragranular nucleation of ferritic laths. Thus, this behavior did not show an obvious refinement effect on HAZ microstructure. Partial bainite microstructure revealed the ferritic lath structures always first form at the beginning of the transformation irrespective of the final morphologies of microstructure (granular bainite or bainitic ferrite), implying that the granular bainite is actually derived from the ferritic lath structures although these lath structures will become gradually obscure at the later stages of the transformation.

    更新日期:2020-01-15
  • Probing the surface ultrastructure of Brevibacillus laterosporus using atomic force microscopy
    Micron (IF 1.53) Pub Date : 2020-01-13
    Khalid Alzahrani; Arun Kumar Shukla; Javed Alam; Abdurahman A. Niazy; Abdullah M. Alsouwaileh; Mansour Alhoshan; Jamal Khalid; Hamdan S. Alghamadi

    One of the main obstacles to studying the surface ultrastructure of microbial cells by atomic force microscopy (AFM) is determining how to immobilize live cells on the AFM substrates. Each method has its own advantages and disadvantages. The aim of this study was to characterize a new simple and inexpensive method using two types of polyethersulfone (PES) membrane filters that differ in pore size (micropore and nanopore) to immobilize live and dead Brevibacillus laterosporus for AFM imaging. B. laterosporus was easily trapped by the microporous PES membrane, facilitating the successful AFM scanning of the bacterial surface ultrastructure. In addition, B. laterosporus strongly attached to the nanoporous membranes and withstood the pulling forces exerted by the AFM tip during scanning. These methods of immobilization did not affect the cell viability. The nanostructure and roughness of the bacterial surface were also observed for live, fixed, and air-dried cells. Live and dead bacteria displayed similar morphologies at low resolution, while at high resolution, live bacteria displayed a more convoluted surface ("brain-like structure").

    更新日期:2020-01-14
  • Machining accuracy detection of PCB hole by X-ray micro-CT
    Micron (IF 1.53) Pub Date : 2020-01-13
    Wenbin Tao; Ying Xu; Hao Liu; Chengyong Wang; Lijuan Zheng

    Over the past few years, non-destructive testing plays an increasingly important role in the accuracy detection of PCB manufacturing. Due to the complexity of PCB materials and the development of PCB towards high density. So far, no method has been described which can semi-automatically detect the machining accuracy of PCB array holes based on three-dimensional structural data. Here, we propose an efficient method to detect the machining accuracy of PCB array holes by X-ray micro-CT. Firstly, the overall three-dimensional structural data of the sample was obtained by CT scanning and three-dimensional reconstruction. And then all the information of array holes could be extracted and visual analyzed. Finally, the measured values of PCB machining accuracy were gained according to the designed algorithms, such as straightness error, process capability index, cylindricity error and three-dimensional surface roughness. The method that based on X-ray micro-CT can get the results of PCB array holes’ machining accuracy precisely and efficiently. The same principle also provides a direction for promoting the development of micro-CT in PCB industry.

    更新日期:2020-01-14
  • In situ observation of twin-assisted grain growth in nanometer-scaled metal
    Micron (IF 1.53) Pub Date : 2020-01-11
    Suyun He; Chunyang Wang; Lu Qi; Hengqiang Ye; Kui Du

    For nanometer-scaled materials, grain boundary behaviors, such as grain coalescence and grain boundary migration, contribute significantly to the plasticity of materials. While mechanically driven grain growth has been observed in nanometer-scaled metals, its underlying mechanisms are still poorly understood especially for those correlated with twins. By using in situ aberration-corrected transmission electron microscopy and precession electron diffraction, we have directly revealed nanotwin assisted grain growth for low angle grain boundaries. The grains with low angle grain boundaries coalesce by firstly forming twin pairs, whose coherent twin boundaries then serve as fast lanes for dislocations, and thus dissolving the low angle grain boundaries. During this process, the constitute dislocations of the low angle grain boundaries decompose into Shockley partial dislocations, which subsequently move along the coherent twin boundaries. After all the constitute dislocations dissociate and move out, two grains will coalesce and twin pairs merge into complete twin lamellae. For high angle grain boundaries, portions of grain boundaries intersected with nanotwins show higher mobility for migration under external stress. This investigation provides insight to twin related grain boundary behaviors in nanometer-scaled metals.

    更新日期:2020-01-13
  • Nano and micro biomechanical analyses of the nucleus pulposus after in situ immobilization in rats
    Micron (IF 1.53) Pub Date : 2020-01-07
    Ting Liang; Dong-Yan Zhong; Yan-Jun Che; Xi Chen; Jiang-Bo Guo; Hui-Lin Yang; Zong-Ping Luo

    Immobilization can lead to intervertebral disc degeneration. The biomechanical characteristics of such discs have not so far been investigated at the micro- or nanoscale, the level at which cells sense and respond to the surrounding environment. This study aimed to characterize changes in the elastic modulus of the collagen fibrils in the nucleus pulposus at the nanoscale and correlate this with micro-biomechanical properties of the nucleus pulposus after immobilization, in addition to observation of tissue histology and its gene expressions. An immobilization system was used on the rat tail with an external fixation device. The elastic modulus was measured using both nano and micro probes for atomic force microscopy after 4 and 8 weeks of immobilization. Histology of the tissue was observed following hematoxylin and eosin staining. Gene expression in the annulus fibrosus tissue was quantified using real-time reverse transcription-polymerase chain reaction. The elastic modulus of the collagen fibrils in the nucleus pulposus at the nanoscale increased from 74.07 ± 17.06 MPa in the control to 90.06 ± 25.51 MPa after 8 weeks (P = 0.007), and from 33.51 ± 9.33 kPa to 43.18 ± 12.08 kPa at the microscale (P = 0.002). After immobilization for 8 weeks, a greater number of cells were observed by histology to be aggregated within the nucleus pulposus. Collagen II (P = 0.007) and aggrecan (P = 0.003) gene expression were downregulated whereas collagen I (P = 0.002), MMP-3 (P < 0.001), MMP-13 (P < 0.001) and ADAMTs-4 (P < 0.001) were upregulated. Immobilization not only influenced individual collagen fibrils at the nanoscale, but also altered the micro-biomechanics and cell response in the nucleus pulposus. These results suggest that significant changes occur in intervertebral discs at both scales after immobilization, a situation about which clinicians should be aware when immobilization has to be used clinically.

    更新日期:2020-01-07
  • Molecular Dynamics Simulation of Strengthening Dependence on Precipitate Cr Composition in Fe-15at.%Cr Alloy
    Micron (IF 1.53) Pub Date : 2020-01-03
    Shehu Adam Ibrahim; Qingyu Wang; Yue Zhang; Mohammed Ado; Gyang Davou Chung; M. Mustafa Azeem

    Molecular Dynamics simulation was employed to study precipitate composition dependence on strengthening. Edge dislocation interaction with pure, 80at.%, and 60at.% Cr precipitates of different sizes in a matrix of Fe-15at.%Cr was investigated. The precipitates were found to be relatively hard. This is evident from the absence of shearing mechanism after the dislocation has bypassed them, the formation of an Orowan-like dislocation shape, and comparatively higher stress values. Precipitates with higher Cr content were found to greatly impede dislocation glide as indicated by the time taken by the dislocation to bypass them. The composition dependence on critical unpinning stress was also observed. The interaction of edge dislocation with precipitates having higher Cr composition leads to higher critical unpinning stress. The extent of critical unpinning stress dependence on precipitate composition is, however, not up to what was reported previously. Besides, the study has also confirmed the fact that α’ precipitation results in the hardening of high Cr ferritic/martensitic steels.

    更新日期:2020-01-04
  • Biophysical Changes Caused by Altered MUC13 Expression in Pancreatic Cancer Cells
    Micron (IF 1.53) Pub Date : 2020-01-03
    Andrew E. Massey; Kyle A. Doxtater; Murali M. Yallapu; Subhash C. Chauhan
    更新日期:2020-01-04
  • Life and its Traces in Antarctica’s McMurdo Dry Valley Paleolakes: A Survey of Preservation
    Micron (IF 1.53) Pub Date : 2019-12-30
    Samuel R. Greenfield; Scott W. Tighe; Yu Bai; David S. Goerlitz; Michele Von Turkovich; Douglas J. Taatjes; Julie A. Dragon; Sarah Stewart Johnson

    The extremely cold and arid conditions of Antarctica make it uniquely positioned to investigate fundamental questions regarding the persistence of life in extreme environments. Within the McMurdo Dry Valleys and surrounding mountain ranges are multiple ancient relict lakes, paleolakes, with lacustrine deposits spanning from thousands to millions of years in age. Here we present data from light microscopy, scanning electron microscopy, electron dispersive x-ray spectroscopy, and radiocarbon dating to catalog the remarkable range of life preserved within these deposits. This includes intact microbes and nanobacteria-sized cocci, CaCO3 precipitations consistent with biogenic calcium, previously undescribed net-like structures, possible dormant spores, and long-extinct yet exquisitely preserved non-vascular plants. These images provide an important reference for further microbiome investigations of Antarctic paleolake samples. In addition, these findings may provide a visual reference for the use of subsurface groundwater microbial communities as an analogue for paleolake subsurface water on planets such as Mars.

    更新日期:2019-12-30
  • Microscopic imaging of human bloodstains: testing the potential of a confocal laser scanning microscope as an alternative to SEMs
    Micron (IF 1.53) Pub Date : 2019-12-30
    Policarp Hortolà

    The forensic interest on human bloodstains derives from their relation to crime investigation, whereas an archaeological and ethnographic concern arises from their occurrence because of warfare and ritual. The development of digital reflected light microscopes provided an opportunity to use ligh microscopy to study surface topographies in a more accurate way than previously. However, this enhancement has been focused on increasing magnification rather than resolution. An advanced type of light microscope is the confocal laser scanning microscope (CLSM). Its potential as an alternative to scanning electron microscopes (SEMs) for imaging human bloodstains was tested. A fragment of stone (brown chert) was smeared with human peripheral blood, air-dried, and stored indoors. After nearly two years, the sample was examined and imaged using an Olympus LEXT OLS4000 CLSM. The surface detail of CLSM images appeared to be comparatively lower than that of SEM micrographs of coated bloodstains taken at high-vacuum mode and high accelerating voltage, similar to that of SEM micrographs of uncoated bloodstains taken at low-vacuum mode and high accelerating voltage, and similar to or even higher than that of SEM micrographs of uncoated bloodstains taken at high-vacuum mode and low accelerating voltage. These results suggest that a CLSM is a practical alternative to SEMs for imaging human bloodstains when a very-high level of surface detail is not required.

    更新日期:2019-12-30
  • Anti-degranulation response of herbal formula in RBL-2H3 cells
    Micron (IF 1.53) Pub Date : 2019-12-28
    Jing Hu; Yujuan Chen; Jiajing Zhu; Mingyan Gao; Jiani Li; Zhengxun Song; Hongmei Xu; Zuobin Wang

    Allergic diseases not only bring serious economic burden to the patients, but also consume a lot of substantial resources of social medical systems. Thus, the prevention and treatment of allergic diseases are imperative. In this study, the anti-degranulation activity of herbal formula was evaluated using the rat basophil leukemia cells (RBL-2H3) as in vitro model. The morphological and biophysical properties of RBL-2H3 cells before and after treatment with herbal formula were also determined. Notably, the herbal formula exhibits clearly inhibited degranulation by RBL-2H3 cells in a concentration-dependent manner without cytotoxic effect. Therefore, this herbal formula can be used as an alternative and promising therapeutic agent to ameliorate allergic diseases.

    更新日期:2019-12-29
  • Synthesized Bioadsorbent from Fish Scale for Chromium (III) Removal
    Micron (IF 1.53) Pub Date : 2019-12-27
    Firomsa Teshale; R. Karthikeyan; Omprakash Sahu
    更新日期:2019-12-27
  • Image reconstruction for sub-sampled atomic force microscopy images using deep neural networks
    Micron (IF 1.53) Pub Date : 2019-12-26
    Yufan Luo; Sean B. Andersson

    Undersampling is a simple but efficient way to increase the imaging rate of atomic force microscopy (AFM). One major challenge in this approach is that of accurate image reconstruction from a limited number of measurements. In this work, we present a deep neural network (DNN) approach to reconstruct μ-path sub-sampled AFM images. Our network consists of two sub-networks, namely a RED-net and a U-net, in series, and is trained end-to-end from random images masked according to μ-path sub-sampling patterns. Using both simulation and experiments, the DNN is shown to yield better image quality than three existing optimization-based methods for reconstruction: basis pursuit, a variant of total variation minimization, and inpainting.

    更新日期:2019-12-27
  • A review of sample thickness effects on high-resolution transmission electron microscopy imaging
    Micron (IF 1.53) Pub Date : 2019-12-23
    Shouqing Li; Binghui Ge

    High-resolution transmission electron microscopy (HRTEM) is an important approach to analyzing material structures. However, in reality, preparing a sufficiently thin sample for use in HRTEM, based on which images could be interpreted by weak phase object approximation theory, is difficult. During the imaging process, the thickness of the sample has two primary effects—a dynamical effect and a non-linear effect. Both are reviewed in this paper. Considering only the dynamical effect, the Bloch wave method and multislice theory have been proposed to understand the relationship between sample thickness and imaging. These methods exhibit high accuracy but high complexity as well. Sacrificing accuracy, pseudo-weak phase object approximation (PWPOA) theory can provide clues to the relationship in reciprocal space with greater simplicity. Meanwhile, in real space, channeling theory describes the dynamical effect with sufficient accuracy, and with the 1s state approximation, i.e., for a certain range of thicknesses, it provides a physical image and simplified expression with which to describe the relationship between the exit wave and sample thickness. As for the non-linear effect, a method of separating linear and non-linear information using a combination of transmission cross-coefficient theory and PWPOA theory was recently proposed. The variation of non-linear and linear imaging with sample thickness has also been discussed. A deep understanding has been acquired regarding the effects of the sample thickness, but a complete understanding of the HRTEM imaging process for thick samples has remained elusive. This understanding is crucial to the retrieval of structure from HRTEM images.

    更新日期:2019-12-23
  • Structural and microstructural study of novel stacked toroidal carbon nanotubes
    Micron (IF 1.53) Pub Date : 2019-12-21
    Maciej Gubernat; Marcel Zambrzycki; Aneta Fraczek-Szczypta; Stanislaw Blazewicz
    更新日期:2019-12-21
  • Fine structure of mouthparts and forelegs of Euplatypus parallelus (Coleoptera: Curculionidae) with emphasis on the behavior of gallery excavation
    Micron (IF 1.53) Pub Date : 2019-12-20
    Gaoke Lei; Yueguan Fu; Weijian Wu

    Euplatypus parallelus (F.) (Coleoptera: Curculionidae) is one of the most invasive species of all the Platypodinae. It penetrates the xylem and oviposits in its host trees thereby weakening the trunk causing them to break under extreme conditions. Since the beetle has evolved effective drilling mouthparts enough to make wood tunnels, we used a field emission scanning electron microscopy to describe the sexual difference in mouthparts and forelegs morphology of the beetle. E. parallelus has chewing type mouthparts composed of a labrum, a pair of mandibles, a pair of maxillae, and a labium. In females, the size of maxillary palpi, submentum, prementum, and labial palpi are significantly larger than males. E. parallelus forelegs were walking type composed of procoxa, protrochanter, profemur, protibia, protarsus, and propretarsus. We observed no significant differences between the forelegs of males and females, but the procoxa of the males was slightly larger than that of females. The structural differences in mouthparts and forelegs between females and males indicated that females invest more time in gallery excavation than males. Possible functional relationships of these structures are discussed. These studies revealed the mechano-dynamic characteristics of E. parallelus and provided a theoretical basis for exploring the behavior of this beetle.

    更新日期:2019-12-21
  • Estimation of systematic errors committed when approximating length of grain boundaries using edges of rectangular or hexagonal grids of EBSD maps
    Micron (IF 1.53) Pub Date : 2019-12-19
    Piotr Bobrowski

    A method for calculating the overestimation error of grain boundary (GB) length committed when approximating a straight segment of a GB using edges of rectangular or hexagonal grid was given. The relative errors range from 0% to 41.42% and from 15.47% to 33.33%, for the square and hex grids, respectively. The average error values for both kinds of meshes are the same, namely, 27.32%. Comparison of the mathematical calculations with experimental results obtained from Electron Backscatter Diffraction (EBSD) data, indicated that the values of the average overestimation errors may be utilized as correction coefficients to adjust experimental data towards more accurate numbers.

    更新日期:2019-12-19
  • Automatic Microscopic Image Analysis by Moving Window Local Fourier Transform and Machine Learning
    Micron (IF 1.53) Pub Date : 2019-12-11
    Benedykt R. Jany, Arkadiusz Janas, Franciszek Krok
    更新日期:2019-12-11
  • Telencephalon Cytoarchitecture of Tsinling Dwarf Skinks (Scincella Tsinlingensis)
    Micron (IF 1.53) Pub Date : 2019-12-10
    Chun Yang, Lin Li, Zhaoting Kou, Huihui Zhang, Limin Wang, Yu Zhao, Niu Zhu

    The telencephalon of adult Scincella tsinlingensis was detected by light and electron microscopy, which will be used as the basis for further neurobiological comparative studies. The telencephalon of S. tsinlingensis was consisted of paired olfactory bulbs, paired cerebral hemispheres, and a telencephalon medium or impar. Main-olfactory bulb can be classified into six layers such as olfactory nerve fibers layer, glomerular layer, external plexiform layer, mitral layer, internal plexiform layer, granular layer and ependyma layer. The dorsal part of telencephalon contained the cortex and dorsal ventricular ridge. The cerebral cortex of S. tsinlingens was relatively thin, while the dorsal cortex was the thinnest, but gradually thickened as it extended to the medial and lateral cortex. The neural cells, glial cells and ependymal cells widely distributed in the cerebral cortex represented similar ultrastructural characteristics to those described in other vertebrates. Golgi staining revealed multipolar cell, bitufted cell and monotufted cell in three cortical layers of medial cortex. The results indicated that the cytoarchitectonic characteristics of telencephalon in S. tsinlingensis resembled those found in other lizards.

    更新日期:2019-12-11
  • Investigation of Hydrated Smectite Microstructure through Wet Environmental Transmission Electron Microscopy
    Micron (IF 1.53) Pub Date : 2019-12-09
    Ryosuke Kagawa, Yuma Kuwamura, Wen-An Chiou, Stephan Kaufhold, Reiner Dohrmann, Hiroki Minoda

    Water is an essential constituent of all biological materials as well as many non-biological materials. Not only the removal of water may result in undesirable morphological and structure change, the inability to sustain the hydrated conditions in the microscope also prevents the study of reactions which take place in aqueous environment. In order to overcome these problems we used wet environmental-cell transmission electron microscopy TEM (WETEM). Conventional TEM of dry smectite showed well-defined particle outlines (but without a specific shape) and typical smectite aggregates. Selected area electron diffraction (SAD) of dry particles showed stacking of smectite particles (i.e., aggregate) in very clear dot and ring patterns. In contrast, WETEM depicted well-dispersed clay particles showing a variety of different particle shapes. Analysis of SAD patterns obtained from dry and hydrated states illustrated a lattice change in different environments. The small lattice expansion in (h k 0) resulted from the expansion of the (0 0 l) plane resulting from the addition of water molecules in the crystal along the c-axis.

    更新日期:2019-12-09
  • Fully-automatic defects classification and restoration for STM images
    Micron (IF 1.53) Pub Date : 2019-12-05
    Xian-guang Fan, Yi Wu, Yu-Liang Zhi, Hong Xia, Xin Wang

    The Scanning tunneling microscope (STM) is a micro instrument designed for surface morphology with nanometer precision. The restoration of the STM image defects usually needs human judgements and manual positioning because of the diversity of the morphology and the randomness of the defects. This paper provides a new fully-automatic method that combines deep convolutional neural classification network and unique restoration algorithms corresponding to different defects. Aimed at automatically processing compound defects in STM images, the method first predicts what kinds of defects a raw STM image has by a series of parallel binary classification networks, and then decides the process order according to the predicted labels, and finally restores the defects by corresponding global restoration algorithms in order. Experiment results prove the provided method can restore the STM images by self-judging, self-positioning, self-processing without any manual intervention.

    更新日期:2019-12-05
  • Scanning Electron Microscopy as a New Tool for Diagnostic Pathology and Cell Biology
    Micron (IF 1.53) Pub Date : 2019-12-04
    Tzipi Cohen Hyams, Keriya Mam, Murray C. Killingsworth

    Scanning electron microscopy (SEM) use in the biomedical sciences has traditionally been used for characterisation of cell and tissue surface topography. This paper demonstrates the utility of high-resolution scanning electron microscopy (HRSEM) to diagnostic pathology and cell biology ultrastructural examinations. New SEM applications based on the production of transmission electron microscopy-like (TEM-like) images are now possible with the recent introduction of new technologies such as low kV scanning transmission electron microscopy (STEM) detectors, automated scan generators and high-resolution column configurations capable of sub-nanometre resolution. Typical specimen types traditionally imaged by TEM have been examined including renal, lung, prostate and brain tissues. The specimen preparation workflow was unchanged from that routinely used to prepare TEM tissue, apart from replacing copper grids for section mounting with a silicon substrate. These instruments feature a small footprint with little in the way of ancillary equipment, such as water chillers, and are more cost-effective than traditional TEM columns. Also, a new generation of benchtop SEMs have recently become available and have also been assessed for its utility in the tissue pathology and cell biology settings.

    更新日期:2019-12-04
  • Response of inflammatory cells to biodegradable ultra-fine grained Mg-based composites
    Micron (IF 1.53) Pub Date : 2019-11-30
    Mieczyslawa U. Jurczyk, Jakub Żurawski, Przemyslaw K. Wirstlein, Kamil Kowalski, Mieczyslaw Jurczyk

    Ultra-fine grained biodegradable Mg-based Mg1Zn1Mn0.3 Zr - HA and Mg4Y5.5Dy0.5 Zr - 45S5 Bioglass composites have shown great medical potential. Two types of these Mg-based biomaterials subjected to different treatments were tested and as shown earlier they are biocompatible. The aim of the study is to determine how much culture media incubated with these ultra-fine trained Mg-based composites can cause inflammatory reactions and /or periodontal cell death. The incubation of composites in the medium releases metal ions into the solution. It can be assumed that this process is permanent and also occurs in the human body. The results have shown that the effect of proinflammatory IL-6 and TNF- cytokines results in the strongest production of the acute phase proteins in the first day on the Mg1Zn1Mn0.3 Zr-5 wt.% HA-1 wt. % Ag HF-treated biocomposite after immersion for 2 h in 40% HF and then the fastest decrease in these processes on the third day. In turn, the inflammatory process induced on the Mg1Zn1Mn0.3 Zr-5 wt.% HA-1 wt. % Ag biomaterial, in BAX / BCL ratio assessment, is the strongest on the third day and maintains a significantly high level on the following day, which, at the same time, confirms its persistence and development. In addition, these results confirm the successively generated necrotic processes. Ions can induce inflammatory reactions, which in the case of the implant may take a long time, which results in the loss of the implant. Even if the material is biocompatible in rapid in-vitro tests, it can induce inflammation in the body after some time due to the release of ions. Not every treatment improves the material's properties in terms of subsequent safety.

    更新日期:2019-11-30
  • Dynamic spring constants of higher resonance modes of uniform and tapered microcantilevers with tip masses
    Micron (IF 1.53) Pub Date : 2019-11-25
    M.A. Mahmoud

    A comprehensive data set is presented that covers eigenvalues and dynamic stiffness of width-tapered microcantilevers for a wide range of the taper ratio and tip mass ratios. Closed form expressions are presented, which could help designers and researchers in the MEMS field in general, and atomic force microscopy in particular.

    更新日期:2019-11-26
  • Quartz tuning fork mass change sensing for FIB/SEM technology
    Micron (IF 1.53) Pub Date : 2019-11-21
    Piotr Kunicki, Magdalena Moczała, Grzegorz Jóźwiak, Paulina Szymanowska, Tomasz Piasecki, Teodor Gotszalk

    In this paper we present a metrological method for determination of mass density of focused ion beam induced deposition (FIBID) materials using quartz tuning fork (QTF) mass change sensors. Dimension and density determination of FIBID deposited nanostructures is necessary to develop and reliable and repeatable microfabribrication technology of the highest versatility. The proposed metrological methodology allows to determine mass change with 5 pg resolution and accuracy below 5 % if density is considered. The described method is suitable for precise FIBID precursor parameters determination conducted during the deposition as actuation and signal read-out of the applied QTF can be performed electrically. High accuracy, resolution and stability are ensured due to excellent properties of quartz forming the sensor structure.

    更新日期:2019-11-21
  • A High Angle Scattering, Stable Amorphous Metal TEM Specimen for Measuring the Information Envelop of Electron Microscopes
    Micron (IF 1.53) Pub Date : 2019-11-19
    Rodney A. Herring

    An amorphous metal (a-metal) TEM specimen suitable for measuring the information envelop of (S)TEM electron microscopes is presented. Its features include producing high angle electron scattering intensities and having good structural stability compared with commonly used specimens of amorphous carbon (a-C) and Au islands supported on a-C substrate.

    更新日期:2019-11-20
  • 更新日期:2019-11-18
  • Determination of viscohyperelastic properties of tubule epithelial cells by an approach combined with AFM nanoindentation and finite element analysis
    Micron (IF 1.53) Pub Date : 2019-11-13
    Lei Wang, Liguo Tian, Ying Wang, Wenxiao Zhang, Zuobin Wang, Xianping Liu

    Tubule epithelial cell is a complex element that not only exhibits elasticity behaviour, but also presents nonlinear and time-dependent behaviour during any stage of its life cycle. Responses of tubule epithelial cells to physical stimuli are influenced by their mechanical properties. However, accurately constitution of their mechanical properties is still a challenge and the characterisation mechanism is far from sophisticated. In addition, the particular mechanism that determines the mechanical response is still unclear. In order to overcome this limit, an approach combined with AFM nanoindentation experiment and computation modelling by a viscohyperelastic model is developed to describe the complex behaviour in the current study. Viscohyperelastic parameters of tubule epithelial cells treated and untreated with drug Cytochalasin D are obtained by the optimization algorithm applied in this approach. The comparison between treated and untreated results indicate that larger amount of relaxation was observed due to the disruption of cytoskeleton when using drug Cytochalasin D. Our results demonstrate the feasibility of this approach to monitor the variation of these viscohyperelastic parameters, which can be used as an effective index for renal disease diagnosed and drug evaluation.

    更新日期:2019-11-13
  • Comparative study with scanning electron microscopy on the antennal sensilla of two main castes of Coptotermes formosanus Shiraki (Blattaria:Rhinotermitidae)
    Micron (IF 1.53) Pub Date : 2019-11-13
    Bing-Xian Fu, Nian-Hang Rong, Jian Hong, Zeng-Rong Zhu, Jian-Chu Mo, Dayu Zhang

    Sensilla on antennae of the workers and soldiers of Coptotermes formosanus Shiraki were examined by scanning electron microscopy in this study. As the two castes were allocated totally different tasks in the termite colony, we wondered if there was a big difference between their antennae which were recognized as the main sensory appendages of insects. Therefore, detailed information about the morphology, distribution and abundance of various types of sensilla was described in this report. However, our results showed no obvious caste dimorphism was observed. The morphology of antennae and sensilla as well as the general sensilla distribution pattern did not differ between the workers and soldiers of C. formosanus. In total, seven types of sensilla including sensilla chaetica (I, II, III), Böhm bristles, sensilla campaniformia (I, II, III), sensilla trichodea, sensilla basiconica, sensilla trichodea curvata and sensilla capitula were found on the antennae. Additionally, small apertures were found scattered randomly in the antennal cuticle. Functions of these sensilla or structures were proposed to be mechanoreceptors, chemo-receptors, thermo-hygroreceptors, co2-receptors etc. which probably play crucial roles in their various social behaviors.

    更新日期:2019-11-13
  • High content analysis of granuloma histology and neutrophilic inflammation in adult zebrafish infected with Mycobacterium marinum
    Micron (IF 1.53) Pub Date : 2019-11-13
    Tina Cheng, Julia Y. Kam, Matt D. Johansen, Stefan H. Oehlers

    Infection of zebrafish with natural pathogen Mycobacterium marinum is a useful surrogate for studying the human granulomatous inflammatory response to infection by Mycobacterium tuberculosis. The adaptive immune system of the adult stage zebrafish offers an advance on the commonly used embryo infection model as adult zebrafish form granulomas with striking similarities to human-M. tuberculosis granulomas. Here, we present workflows to perform high content analyses of granulomas in adult zebrafish infected with M. marinum by cryosectioning to take advantage of strong endogenous transgenic fluorescence adapted from common zebrafish embryo infection tools. Specific guides to classifying granuloma necrosis and organisation, quantifying bacterial burden and leukocyte infiltration of granulomas, visualizing foam cell formation, analysing extracellular matrix remodelling and granuloma fibrosis are also provided. We use these methods to characterize neutrophil recruitment to M. marinum granulomas across time and find an inverse relation to granuloma necrosis suggesting granuloma necrosis is not a marker of immunopathology in the natural infection system of the adult zebrafish-M. marinum pairing. The methods can be easily translated to studying the zebrafish adaptive immune response to other chronic and granuloma-forming pathogens.

    更新日期:2019-11-13
  • Lippia sidoides and Lippia origanoides essential oils affect the viability, motility and ultrastructure of Trypanosoma cruzi
    Micron (IF 1.53) Pub Date : 2019-11-12
    Andrezza Raposo Borges de Melo, Taciana Mirely Maciel Higino, Aline Dulce Pitt da Rocha Oliveira, Adriana Fontes, Diego César Nunes da Silva, Maria Carolina Accioly Brelaz de Castro, José Arimatéia Dantas Lopes, Regina Celia Bressan Queiroz de Figueiredo
    更新日期:2019-11-13
  • Low concentrations of acetylcarvacrol induce drastic morphological damages in ovaries of surviving Rhipicephalus sanguineus sensu lato ticks (Acari: Ixodidae)
    Micron (IF 1.53) Pub Date : 2019-11-08
    Isaac Filipe Moreira Konig, Marcos Vinícius Silva de Oliveira, Raquel Romano Palmeira Gonçalves, Ana Paula Peconick, Sérgio Scherrer Thomasi, Luís Adriano Anholeto, José Ribamar Lima-de-Souza, Maria Izabel Camargo-Mathias, Rafael Neodini Remedio
    更新日期:2019-11-08
  • Characterization of age-dependent variability in the flank scales of two scorpaeniformes fishes by applying light and scanning electron microscopy imaging
    Micron (IF 1.53) Pub Date : 2019-11-06
    Mina Motamedi, Azad Teimori, Vahid Amiri, Majid Askari Hesni

    The morphology of scales from four flank regions in two species of Scorpaeniforme fishes of the family Platycephalidae was studied by applying light and scanning electron microscopy, and age-dependent variability of scale structures was discussed. The scales of four flank regions from three size classes in both species were ctenoid. The posterior margin of all the ctenoid scales was formed by two rows of cteni, while the three complete rows of cteni were not observed in the examined scales. The cteni of both rows were similar in morphology. Some scale characteristics showed alteration during the fish growth, including the shape of the anterior region of scale in Platycephalus indicus, the presence of lepidonts in Grammoplites suppositus, and the general shape of scale as well as the indices SCL.SCW and JSW.SL in both species. Also, the number of cteni in posterior margin of scales was increased during fish development, while their general morphology did not change significantly. The number of cteni in the scales of small and large fishes in G. suppositus was found to be obviously lower than P. indicus. By considering the function of lepidonts in improving the hydrodynamic efficiency of swimming, it can be assumed that G. suppositus is not probably very active in swimming as P. indicus. As a conclusion, modification in the ornamentations of the posterior region are subject to alteration during the growth of the fish. Besides its developmental changes, some scale characters in the adult forms have taxonomic significance, including the square-shaped scales in P. indicus vs. the oval-shaped scale in G. suppositus; a total of 26-31 radii in the anterior field in P. indicus vs. 11-12 radii in G. suppositus; the presence of many (54-58) cteni in the posterior part in P. indicus vs. a moderate (19-23) cteni in G. suppositus. These characters could be used as additional morphological data to be used for studying systematics and even phylogeny of the flathead fishes.

    更新日期:2019-11-06
  • Morphological and optical features of the apposition compound eye of Monochamus alternatus Hope (Coleoptera: Cerambycidae)
    Micron (IF 1.53) Pub Date : 2019-10-10
    Chao Wen, Tao Ma, Yangxiao Deng, Chuanhe Liu, Shiping Liang, Junbao Wen, Cai Wang, Xiujun Wen

    The Japanese pine sawyer beetle, Monochamus alternatus Hope (Coleoptera: Cerambycidae) is currently the most destructive forest pest as it transmits the pine wilt nematode Bursaphelenchus xylophilus. Morphological, optical features and dark/light adaptational changes of the compound eyes of M. alternatus adults were examined by light, scanning and transmission electron microscopy. The eye of M. alternatus is apposition type and contains 489–712 ommatidia, depending on the beetle’s body size. Each ommatidium features a large corneal lens, composed of a thick inner lens (ILU) and a thin outer lens unit (OLU); an acone-type of cone of four cone cells, a semi-fused type of rhabdom formed by eight retinular cells (two central cells: R7-R8 surrounded by six peripheral cells: R1-R6). Dark/light adaptational changes affect size and shape of the cones as well as the rhabdom’s cross-sectional area and outline, to optimize the amount of light that reaches the photopigment. The compound eyes of M. alternatus have an F-number of 0.94, an interommatidial angle of 5.34°, an eye parameter P of 4.98 μm rad and a ratio of acceptance to interommatidial angle of 0.45. The eye is characterized by relatively poor spatial resolution, but can be expected to exhibit high absolute sensitivity and contrast in dim light.

    更新日期:2019-11-04
  • Automatic identification of cashmere and wool fibers based on the morphological features analysis
    Micron (IF 1.53) Pub Date : 2019-10-09
    Wenyu Xing, Yiwen Liu, Na Deng, Binjie Xin, Wenzhen Wang, Yang Chen

    Identification of wool and cashmere extremely similar fibers is always an important topic in the textile industry. In order to solve this problem much better, a novel fiber identification method based on the extraction and analysis of the morphological features was proposed in this paper. Firstly, the original fiber images were captured by the self-developed system including the optical microscope and digital camera. The influence of the acquisition process may lead to the low contrast and impurities, so the original fiber images needed to be processed by the image enhancement and de-noise to obtain the available fiber images with a better quality. Then the hessian matrix of processed images was put into the Frangi filter to detect the edge of the fiber scales, and the binary images of filter output images were processed to obtain the signal-pixel scale skeleton. The connected region labeling algorithm can be adopted for the scale skeleton images to mark and extract every scale from the whole fiber according to the different color information. Next, the three morphological features including scale height, fiber diameter and their ratio can be calculated by the self-defined vertical line rotation analysis method, and the mean value of five different scales was calculated as the final features to describe one fiber. In the experiment, 500 fiber cashmere and 500 wool fiber images were collected for the whole research, and a Bayesian classification model for identifying wool and cashmere fibers was established based on the statistical assumptions of three morphological characteristics. The results show that the identification accuracy of the method proposed in this paper could reached the 94.2%. It also proves that this novel method can be used for the identification of cashmere and wool extremely similar animal fibers.

    更新日期:2019-11-04
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