A novel method to estimate the thickness of the depletion layer of an X-ray CCD

2002 ◽  
Vol 495 (3) ◽  
pp. 232-239 ◽  
Author(s):  
H Awaki ◽  
K Tachibana ◽  
Y Tamai ◽  
K Yamamoto ◽  
S Kitamoto ◽  
...  
Keyword(s):  
Depletion Layer ◽  
X Ray ◽  
Novel Method

scholarly journals COVID-19 infection map generation and detection from chest X-ray images

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Aysen Degerli ◽  
Mete Ahishali ◽  
Mehmet Yamac ◽  
Serkan Kiranyaz ◽  
Muhammad E. H. Chowdhury ◽  
...  
Keyword(s):  
State Of The Art ◽  
Ground Truth ◽  
Clinical Use ◽  
X Ray ◽  
Learning Techniques ◽  
Map Generation ◽  
Severity Grading ◽  
Chest X Ray ◽  
Novel Method ◽  
Aided Diagnosis

AbstractComputer-aided diagnosis has become a necessity for accurate and immediate coronavirus disease 2019 (COVID-19) detection to aid treatment and prevent the spread of the virus. Numerous studies have proposed to use Deep Learning techniques for COVID-19 diagnosis. However, they have used very limited chest X-ray (CXR) image repositories for evaluation with a small number, a few hundreds, of COVID-19 samples. Moreover, these methods can neither localize nor grade the severity of COVID-19 infection. For this purpose, recent studies proposed to explore the activation maps of deep networks. However, they remain inaccurate for localizing the actual infestation making them unreliable for clinical use. This study proposes a novel method for the joint localization, severity grading, and detection of COVID-19 from CXR images by generating the so-called infection maps. To accomplish this, we have compiled the largest dataset with 119,316 CXR images including 2951 COVID-19 samples, where the annotation of the ground-truth segmentation masks is performed on CXRs by a novel collaborative human–machine approach. Furthermore, we publicly release the first CXR dataset with the ground-truth segmentation masks of the COVID-19 infected regions. A detailed set of experiments show that state-of-the-art segmentation networks can learn to localize COVID-19 infection with an F1-score of 83.20%, which is significantly superior to the activation maps created by the previous methods. Finally, the proposed approach achieved a COVID-19 detection performance with 94.96% sensitivity and 99.88% specificity.

scholarly journals The Influence of Varying Fluorination Patterns on the Thermodynamics and Kinetics of Benzenesulfonamide Binding to Human Carbonic Anhydrase II

Biomolecules ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 509 ◽  
Author(s):  
Steffen Glöckner ◽  
Khang Ngo ◽  
Björn Wagner ◽  
Andreas Heine ◽  
Gerhard Klebe
Keyword(s):  
Carbonic Anhydrase ◽  
Carbonic Anhydrase Ii ◽  
The Novel ◽  
Binding Modes ◽  
X Ray ◽  
Structure Activity ◽  
Small Set ◽  
Novel Method ◽  
Human Carbonic Anhydrase ◽  
Kinetics Of

The fluorination of lead-like compounds is a common tool in medicinal chemistry to alter molecular properties in various ways and with different goals. We herein present a detailed study of the binding of fluorinated benzenesulfonamides to human Carbonic Anhydrase II by complementing macromolecular X-ray crystallographic observations with thermodynamic and kinetic data collected with the novel method of kinITC. Our findings comprise so far unknown alternative binding modes in the crystalline state for some of the investigated compounds as well as complex thermodynamic and kinetic structure-activity relationships. They suggest that fluorination of the benzenesulfonamide core is especially advantageous in one position with respect to the kinetic signatures of binding and that a higher degree of fluorination does not necessarily provide for a higher affinity or more favorable kinetic binding profiles. Lastly, we propose a relationship between the kinetics of binding and ligand acidity based on a small set of compounds with similar substitution patterns.

Dark-Field X-Ray Microscopy of Immunogold-Labeled Cells

1996 ◽  
Vol 2 (2) ◽  
pp. 53-62 ◽  
Author(s):  
Henry N. Chapman ◽  
Jenny Fu ◽  
Chris Jacobsen ◽  
Shawn Williams
Keyword(s):  
Colloidal Gold ◽  
Dark Field Image ◽  
Dark Field ◽  
X Rays ◽  
X Ray ◽  
Scanning Transmission ◽  
A Cell ◽  
Specific Antigens ◽  
Genetic Sequences ◽  
Novel Method

The methods of immunolabeling make visible the presence of specific antigens, proteins, genetic sequences, or functions of a cell. In this paper we present examples of imaging immunolabels in a scanning transmission x-ray microscope using the novel method of dark-field contrast. Colloidal gold, or silver-enhanced colloidal gold, is used as a label, which strongly scatters x-rays. This leads to a high-contrast dark-field image of the label and reduced radiation dose to the specimen. The x-ray images are compared with electron micrographs of the same labeled, unsectioned, whole cell. It is verified that the dark-field x-ray signal is primarily due to the label and the bright-field x-ray signal, showing absorption due to carbon, is largely unaffected by the label. The label can be well visualized even when it is embedded in or laying behind dense material, such as the cell nucleus. The resolution of the images is measured to be 60 nm, without the need for computer processing. This figure includes the x-ray microscope resolution and the accuracy of the label positioning. The technique should be particularly useful for the study of relatively thick (up to 10 μm), wet, or frozen hydrated specimens.

Preparation of Highly Conductive Polyaniline in Carbamide Aqueous Solution Using SnCl4 as Initiator

2012 ◽  
Vol 476-478 ◽  
pp. 2205-2208 ◽  
Author(s):  
Guan Nan Lin ◽  
Qun Yu ◽  
Wei Wang ◽  
Gui Bao Wang
Keyword(s):  
Aqueous Solution ◽  
Ammonium Persulfate ◽  
Conductivity Measurements ◽  
X Ray ◽  
New Class ◽  
Vis Spectroscopy ◽  
Polymerization System ◽  
Novel Method ◽  
Conductive Polyaniline ◽  
Hydrolysis Of

In this paper, we demonstrated a novel method for the preparation of highly conductive polyaniline (PANI) compounded with Sn(OH)4. We obtained the PANI directly in the oxidation polymerization system via simultaneous reaction of aniline (using ammonium persulfate, APS as oxidant) and SnCl4 in carbamide aqueous solution. The resulting PANI was compounded with Sn(OH)4 had been characterized by FTIR, UV-Vis spectroscopy, X-ray diffractometry, thermal analysis, scanning electron microscope and conductivity measurements, and the results showed that PANI was in well doped state due to the hydrolysis of APS and the complex between PANI and Sn(OH)4. We are sure this alkali-guided polymerization to obtain conductive PANI will lead to the preparation of a new class of PANI composites.

Preparation and Research of Anionic and Cationic Secondary Modified Organophilic Montmorillonite

2011 ◽  
Vol 396-398 ◽  
pp. 417-420 ◽  
Author(s):  
Xiao Hua Gu ◽  
Shi Wei Li ◽  
Bing Zheng ◽  
Jia Liang Zhou
Keyword(s):  
Cationic Surfactants ◽  
Anionic Surfactants ◽  
Interlayer Spacing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Modification Effect ◽  
Novel Method ◽  
Organophilic Montmorillonite

A novel method is proposed to modify montmorillonite with anionic surfactants, cationic surfactants and halides stearyl cationic surfactants made by our group (Z-surfactant). The structure of organophilic montmorillonite (OMMT) was characterized by XRD and TG. The results of X-ray diffraction show that cationic surfactants and anionic surfactants are all intercalated into the layer of MMT. When modified with cationic surfactants, the interlayer spacing of MMT increases from 1.24 nm to the maximum of 3.76 nm. When it was secondary modified, the insertion order is to insert the cation first and then the anion. The interlayer spacing of montmorillonite increases to 4.80 nm, the modification effect is well.

scholarly journals Protein microcrystallography using synchrotron radiation

IUCrJ ◽  
2017 ◽  
Vol 4 (5) ◽  
pp. 529-539 ◽  
Author(s):  
Masaki Yamamoto ◽  
Kunio Hirata ◽  
Keitaro Yamashita ◽  
Kazuya Hasegawa ◽  
Go Ueno ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Data Collection ◽  
Diffraction Data ◽  
Structure Determination ◽  
Structural Features ◽  
X Ray ◽  
Data Collection Strategy ◽  
Technological Developments ◽  
Novel Method

The progress in X-ray microbeam applications using synchrotron radiation is beneficial to structure determination from macromolecular microcrystals such as smallin mesocrystals. However, the high intensity of microbeams causes severe radiation damage, which worsens both the statistical quality of diffraction data and their resolution, and in the worst cases results in the failure of structure determination. Even in the event of successful structure determination, site-specific damage can lead to the misinterpretation of structural features. In order to overcome this issue, technological developments in sample handling and delivery, data-collection strategy and data processing have been made. For a few crystals with dimensions of the order of 10 µm, an elegant two-step scanning strategy works well. For smaller samples, the development of a novel method to analyze multiple isomorphous microcrystals was motivated by the success of serial femtosecond crystallography with X-ray free-electron lasers. This method overcame the radiation-dose limit in diffraction data collection by using a sufficient number of crystals. Here, important technologies and the future prospects for microcrystallography are discussed.

Mechanical Behavior of the Cr3C2 Compound at High Pressure and High Temperature

2015 ◽  
Vol 1120-1121 ◽  
pp. 1187-1193 ◽  
Author(s):  
Bin Li Jiang ◽  
Zi Li Kou ◽  
De Jiang Ma ◽  
Yong Kun Wang ◽  
Chun Xia Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Pressure ◽  
Relative Density ◽  
X Ray Diffraction ◽  
Density Measurements ◽  
X Ray ◽  
Hardness Tests ◽  
Novel Method ◽  
Heat Preservation

In the present study, we present a novel method to sinter Cr3C2 powders under high pressure without any addittives. The sintering Cr3C2 samples were charaterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), relative density measurements, Vicker’s hardness tests and Fracture toughness tests. The reasults show that Cr3C2 powders could be sintered to be bulk under the conditions of 3-5 GPa, 800-1200 °C and the heat preservation for 15 min. Moreover, the sintering body of Cr3C2 compound with the relative density of 99.84% by simultaneously tuning the pressure-temperature conditions exhibited excellent mechanical properties: a Vickers hardness of 20.3 GPa and a fracture toughness of ~8.9 MPam1/2. These properties were much higher than that by using the previous methods. The temperature condition obtained good mechanical properties in the experiment was about 1/3 lower than that using any other methods owing to the high pressure.

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