scholarly journals Sponge grade body fossil with cellular resolution dating 60 Myr before the Cambrian

2015 ◽  
Vol 112 (12) ◽  
pp. E1453-E1460 ◽  
Author(s):  
Zongjun Yin ◽  
Maoyan Zhu ◽  
Eric H. Davidson ◽  
David J. Bottjer ◽  
Fangchen Zhao ◽  
...  
Keyword(s):  
Cellular Structure ◽  
External Surface ◽  
Regular Pattern ◽  
Single Specimen ◽  
Cell Type ◽  
X Ray ◽  
Dense Patch ◽  
Cellular Resolution ◽  
Character Set ◽  
Body Fossil

An extraordinarily well preserved, 600-million-year (Myr)-old, three-dimensionally phosphatized fossil displaying multiple independent characters of modern adult sponges has been analyzed by SEM and synchrotron X-ray tomography. The fossilized animal (Eocyathispongia qiania gen. et sp. nov.) is slightly more than 1.2 mm wide and 1.1 mm tall, is composed of hundreds of thousands of cells, and has a gross structure consisting of three adjacent hollow tubes sharing a common base. The main tube is crowned with a large open funnel, and the others end in osculum-like openings to the exterior. The external surface is densely covered with flat tile-like cells closely resembling sponge pinacocytes, and this layer is punctuated with smaller pores. A dense patch of external structures that display the form of a lawn of sponge papillae has also survived. Within the main funnel, an area where features of the inner surface are preserved displays a regular pattern of uniform pits. Many of them are surrounded individually by distinct collars, mounted in a supporting reticulum. The possibility cannot be excluded that these pits are the remains of a field of choanocytes. The character set evinced by this specimen, ranging from general anatomy to cell type, uniquely indicates that this specimen is a fossil of probable poriferan affinity. So far, we have only this single specimen, and although its organized and complex cellular structure precludes any reasonable interpretation that its origin is abiogenic, confirmation that it is indeed a fossilized sponge will clearly require discovery of additional specimens.

In situ Fast X-ray Tomography Study of the Evolution of Cellular Structure in Bread Dough During Proving and Baking

2008 ◽  
pp. 265-272 ◽  
Author(s):  
P. Babin ◽  
G. Della Valle ◽  
H. Chiron ◽  
P. Cloetens ◽  
J. Hoszowska ◽  
...  
Keyword(s):  
Cellular Structure ◽  
Bread Dough ◽  
X Ray

scholarly journals Integrative multi-omics analyses identify cell-type disease genes and regulatory networks across schizophrenia and Alzheimer’s disease

2020 ◽  
Author(s):  
Mufang Ying ◽  
Peter Rehani ◽  
Panagiotis Roussos ◽  
Daifeng Wang
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Gene Regulatory Networks ◽  
Regulatory Networks ◽  
Regulatory Elements ◽  
Disease Genes ◽  
Omics Data ◽  
Cell Type ◽  
Cellular Resolution ◽  
Gene Regulatory

AbstractStrong phenotype-genotype associations have been reported across brain diseases. However, understanding underlying gene regulatory mechanisms remains challenging, especially at the cellular level. To address this, we integrated the multi-omics data at the cellular resolution of the human brain: cell-type chromatin interactions, epigenomics and single cell transcriptomics, and predicted cell-type gene regulatory networks linking transcription factors, distal regulatory elements and target genes (e.g., excitatory and inhibitory neurons, microglia, oligodendrocyte). Using these cell-type networks and disease risk variants, we further identified the cell-type disease genes and regulatory networks for schizophrenia and Alzheimer’s disease. The celltype regulatory elements (e.g., enhancers) in the networks were also found to be potential pleiotropic regulatory loci for a variety of diseases. Further enrichment analyses including gene ontology and KEGG pathways revealed potential novel cross-disease and disease-specific molecular functions, advancing knowledge on the interplays among genetic, transcriptional and epigenetic risks at the cellular resolution between neurodegenerative and neuropsychiatric diseases. Finally, we summarized our computational analyses as a general-purpose pipeline for predicting gene regulatory networks via multi-omics data.

scholarly journals The Amounts of Water Adsorbed to the Surface of Clay Minerals at the Plastic Limit

2017 ◽  
Vol 64 (3-4) ◽  
pp. 155-162
Author(s):  
Aleksandra Gorączko ◽  
Andrzej Olchawa
Keyword(s):  
Surface Area ◽  
External Surface ◽  
Solid Phase ◽  
Water System ◽  
Basal Spacing ◽  
Plastic Limit ◽  
X Ray Diffraction ◽  
External Surface Area ◽  
X Ray ◽  
Water Layers

AbstractThe paper presents results of a study on the amount of water associated with the solid phase of the clay water system at the plastic limit. Two model monomineral clays, namely kaolinite, and montmorillonite, were used in the study. The latter was obtained by gravitational sedimentation of Na-bentonite (Wyoming).The calculated mean number of water molecule layers on the external surface of montmorillonite was 14.4, and water in interlayer spaces constituted 0.3 of the water mass at the plastic limit.The number of water layers on the external surface of kaolinite particles was 63, which was related to the higher density of the surface electrical charge of kaolinite compared to that of montmorillonite.The calculations were made on the basis of the external surface area of clays and the basal spacing at the plastic limit measured by an X-ray diffraction test. The external surface area of clays was estimated by measuring sorption at a relative humidity p/p0 = 0.5.

Microstructural Study of a Passivation Layer on GaAs: An Application of X-Ray Reflectivity Under Grazing Angles Using a Synchrotron Source

2003 ◽  
Vol 10 (02n03) ◽  
pp. 373-379 ◽  
Author(s):  
K. E. Crompton ◽  
T. R. Finlayson ◽  
C. Kirchner ◽  
M. Seitz ◽  
U. Klemradt
Keyword(s):  
External Surface ◽  
Synchrotron Source ◽  
Microstructural Study ◽  
X Ray ◽  
Force Microscopy ◽  
Microstructural Parameters ◽  
Atomic Force ◽  
Potential Applications ◽  
Grazing Angles ◽  
Mode Atomic Force Microscopy

X-ray specular reflectivities of GaAs samples passivated with a thin film of (3-mercaptopropyl)-trimethoxysilane (MPT) have been studied using bending-magnet synchrotron radiation. Various preparation procedures covering etching the GaAs, MPT deposition and its baking have been investigated. An oxide film is always observed between the GaAs and MPT films. The microstructural parameters, such as film thickness, density and interfacial roughness (including the external surface), have been determined from appropriate modeling of the reflectivity. The surface roughness has been compared with a direct measurement using tapping-mode atomic force microscopy. The results are discussed with reference to the potential applications of GaAs as a biosensor.

scholarly journals Comparative Analysis of the Chemical Composition and Microstructure Conformation Between Different Dental Implant Bone Drills

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1866 ◽  
Author(s):  
Gaetano Marenzi ◽  
Josè Camilla Sammartino ◽  
Fabio Scherillo ◽  
Carlo Rengo ◽  
Alfredo De Rosa ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Dental Implant ◽  
Vickers Microhardness ◽  
Martensitic Stainless Steel ◽  
External Surface ◽  
Clinical Performance ◽  
X Ray ◽  
Indentation Force ◽  
Implant Site Preparation ◽  
Surface Conformation

Background: Hardness is considered an important parameter for evaluating the clinical performance of dental implant bone drills. It is connected to the chemical composition, microstructure conformation and manufacture of the surgical drills. Methods: Microstructure of five dental implant drills using scanning electronic microscopy (SEM) integrated with energy dispersive X-ray spectrometry. Vickers microhardness was measured using a CV 2000 microhardness tester with an indentation force of 500 g. Results: Composition of the implant drills was typical of martensitic stainless steel (MSS). The drills contained 13%–17% of Cr; Mo, Si and Mn were present as minor ligands. The examined bone drills showed different external surface conformation and hardness in relation to the different industrial production processes. A rougher external surface and a higher hardness value are characteristics of the surgical bone drills produced by hot forming; the implant drills produced by machining showed mailing lines on their external surface and a lower hardness. Conclusions: Different compositions and treatments were used by the manufacturers to improve the hardness of the external layer of the dental implant drills making them prone to a diverse heat generation during the implant site preparation.

Preparation and Photocatalytic Performance of Nanostructural WO3 Induced by Ion in Hydrothermal Synthesis

2012 ◽  
Vol 580 ◽  
pp. 535-538 ◽  
Author(s):  
Bin Yu ◽  
Hai Feng Chen ◽  
Ting Yan
Keyword(s):  
Methyl Orange ◽  
Photocatalytic Oxidation ◽  
Photocatalytic Performance ◽  
Alkali Metal Cation ◽  
Regular Pattern ◽  
X Ray Diffraction ◽  
Optimal Amount ◽  
X Ray ◽  
Oxidation Performance ◽  
The Impact

WO3 nanocrystals have been successfully synthesized via an ion induced auxiliary hydrothermal method. The experiment products were characterized by powder X-ray diffraction (XRD) and the Photocatalytic oxidation performance of products were characterized by using the photocatalytic oxidation of methyl orange under the condition of hydrogen peroxide. The optimal amount of catalyst required for catalytic oxidation experiments and the concentration of methyl orange (MO) were determined. The experimental results indicated that with he enhancement of metallicity in alkali main group, the photocatalytic activity of the WO3 induced by alkali metal cation increased; The SO42- has higher induce catalytic activity than Cl- when the type and quantity of cation are the same; however, the ion induction on the impact of surface area is quite different, and it founded that they comply with this regular pattern, that is Na+> K+> Li+ and SO42-> Cl-.

scholarly journals Scanning Electron Microscopy and Synchrotron Radiation X-Ray Tomographic Microscopy of 330 Million Year Old Charcoalified Seed Fern Fertile Organs

2009 ◽  
Vol 15 (2) ◽  
pp. 166-173 ◽  
Author(s):  
Andrew C. Scott ◽  
Jean Galtier ◽  
Neil J. Gostling ◽  
Selena Y. Smith ◽  
Margaret E. Collinson ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Synchrotron Radiation ◽  
Materials Science ◽  
Single Specimen ◽  
X Ray ◽  
Swiss Light Source ◽  
Pollen Organ ◽  
Paul Scherrer ◽  
Scanning Electron

AbstractAbundant charcoalified seed fern (pteridosperm) pollen organs and ovules have been recovered from Late Viséan (Mississippian 330 Ma) limestones from Kingswood, Fife, Scotland. To overcome limitations of data collection from these tiny, sometimes unique, fossils, we have combined low vacuum scanning electron microscopy on uncoated specimens with backscatter detector and synchrotron radiation X-ray tomographic microscopy utilizing the Materials Science and TOMCAT beamlines at the Swiss Light Source of the Paul Scherrer Institut. In combination these techniques improve upon traditional cellulose acetate peel sectioning because they enable study of external morphology and internal anatomy in multiple planes of section on a single specimen that is retained intact. The pollen organMelissiothecashows a basal parenchymatous cushion bearing more than 100 sporangia on the distal face. Digital sections show the occurrence of pollen in some sporangia. The described ovule is new and has eight integumentary lobes that are covered in spirally arranged glandular hairs. Virtual longitudinal sections reveal the lobes are free above the pollen chamber. Results are applied in taxonomy and will subsequently contribute to our understanding of the former diversity and evolution of ovules, seeds, and pollen organs in the seed ferns, the first seed-bearing plants to conquer the land.

Structure of oak wood from the Swedish warship Vasa revealed by X-ray scattering and microtomography

Holzforschung ◽  
2012 ◽  
Vol 66 (3) ◽  
Author(s):  
Kirsi Svedström ◽  
Ingela Bjurhager ◽  
Aki Kallonen ◽  
Marko Peura ◽  
Ritva Serimaa
Keyword(s):  
Cellular Structure ◽  
Short Range ◽  
Average Length ◽  
Cellulose Microfibrils ◽  
Crystalline Cellulose ◽  
Oak Wood ◽  
X Ray ◽  
X Ray Scattering ◽  
The Mean ◽  
Ray Scattering

Abstract The degradation of oak wood of the historical warship Vasa was studied, focusing on cellular structure by X-ray microtomography (μCT) and on the nanostructure of the cell wall by wide- and small-angle X-ray scattering (WAXS, SAXS). Solid samples [polyethylene glycol (PEG)-, impregnated and PEG-extracted] were submitted to X-ray analysis and the results compared to those of recent oak. The cellular structure of the Vasa oak was surprisingly well preserved at the micrometer level, according to the μCT images. As revealed by WAXS, the fraction of crystalline cellulose was lower in the Vasa samples compared with recent oak, but the average length and width of cellulose crystallites (25±2 nm and 3.0±0.1 nm, respectively), and the mean microfibril angles (4–9°), showed no significant differences. Accordingly, the crystalline parts of cellulose microfibrils are well preserved in the Vasa oak. The SAXS results indicated a declined short-range order between the cellulose microfibrils and a higher porosity of the Vasa oak compared with recent oak, which may be explained by modification of the hemicellulose-lignin matrix.

scholarly journals Cellular-resolution 3D virtual histology of human coronary arteries using x-ray phase tomography

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
William Vågberg ◽  
Jonas Persson ◽  
Laszlo Szekely ◽  
Hans M. Hertz
Keyword(s):  
Coronary Arteries ◽  
Virtual Histology ◽  
X Ray ◽  
Cellular Resolution
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