X-ray microtomography is a novel method for accurate evaluation of small-bowel mucosal morphology and surface area

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.

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Hydrochloric Acid Modification and Lead Removal Studies on Naturally Occurring Zeolites from Nevada, New Mexico, and Arizona

Processes ◽

10.3390/pr9071238 ◽

2021 ◽

Vol 9 (7) ◽

pp. 1238

Author(s):

Garven M. Huntley ◽

Rudy L. Luck ◽

Michael E. Mullins ◽

Nick K. Newberry

Keyword(s):

New Mexico ◽

Surface Area ◽

Bet Surface Area ◽

Lead Removal ◽

X Ray Diffraction ◽

Sem Images ◽

X Ray ◽

Naturally Occurring ◽

27Al Mas Nmr ◽

Modified Zeolites

Four naturally occurring zeolites were examined to verify their assignments as chabazites AZLB-Ca and AZLB-Na (Bowie, Arizona) and clinoptilolites NM-Ca (Winston, New Mexico) and NV-Na (Ash Meadows, Nevada). Based on powder X-ray diffraction, NM-Ca was discovered to be mostly quartz with some clinoptilolite residues. Treatment with concentrated HCl (12.1 M) acid resulted in AZLB-Ca and AZLB-Na, the chabazite-like species, becoming amorphous, as confirmed by powder X-ray diffraction. In contrast, NM-Ca and NV-Na, which are clinoptilolite-like species, withstood boiling in concentrated HCl acid. This treatment removes calcium, magnesium, sodium, potassium, aluminum, and iron atoms or ions from the framework while leaving the silicon framework intact as confirmed via X-ray fluorescence and diffraction. SEM images on calcined and HCl treated NV-Na were obtained. BET surface area analysis confirmed an increase in surface area for the two zeolites after treatment, NM-Ca 20.0(1) to 111(4) m2/g and NV-Na 19.0(4) to 158(7) m2/g. 29Si and 27Al MAS NMR were performed on the natural and treated NV-Na zeolite, and the data for the natural NV-Na zeolite suggested a Si:Al ratio of 4.33 similar to that determined by X-Ray fluorescence of 4.55. Removal of lead ions from solution decreased from the native NM-Ca, 0.27(14), NV-Na, 1.50(17) meq/g compared to the modified zeolites, 30 min HCl treated NM-Ca 0.06(9) and NV-Na, 0.41(23) meq/g, and also decreased upon K+ ion pretreatment in the HCl modified zeolites.

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Preparation and Characterization of the Sulfur-Impregnated Natural Zeolite Clinoptilolite for Hg(II) Removal from Aqueous Solutions

Processes ◽

10.3390/pr9020217 ◽

2021 ◽

Vol 9 (2) ◽

pp. 217

Author(s):

Marin Ugrina ◽

Martin Gaberšek ◽

Aleksandra Daković ◽

Ivona Nuić

Keyword(s):

Chemical Modification ◽

Aqueous Solutions ◽

Specific Surface ◽

Surface Area ◽

Natural Zeolite ◽

Contact Time ◽

Liquid Ratio ◽

X Ray ◽

Solid Liquid

Sulfur-impregnated zeolite has been obtained from the natural zeolite clinoptilolite by chemical modification with Na2S at 150 °C. The purpose of zeolite impregnation was to enhance the sorption of Hg(II) from aqueous solutions. Chemical analysis, acid and basic properties determined by Bohem’s method, chemical behavior at different pHo values, zeta potential, cation-exchange capacity (CEC), specific surface area, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetry with derivative thermogravimetry (TG-DTG) were used for detailed comparative mineralogical and physico-chemical characterization of natural and sulfur-impregnated zeolites. Results revealed that the surface of the natural zeolite was successfully impregnated with sulfur species in the form of FeS and CaS. Chemical modification caused an increase in basicity and the net negative surface charge due to an increase in oxygen-containing functional groups as well as a decrease in specific surface area and crystallinity due to the formation of sulfur-containing clusters at the zeolite surface. The sorption of Hg(II) species onto the sulfur-impregnated zeolite was affected by the pH, solid/liquid ratio, initial Hg(II) concentration, and contact time. The optimal sorption conditions were determined as pH 2, a solid/liquid ratio of 10 g/L, and a contact time of 800 min. The maximum obtained sorption capacity of the sulfur-impregnated zeolite toward Hg(II) was 1.02 mmol/g. The sorption mechanism of Hg(II) onto the sulfur-impregnated zeolite involves electrostatic attraction, ion exchange, and surface complexation, accompanied by co-precipitation of Hg(II) in the form of HgS. It was found that sulfur-impregnation enhanced the sorption of Hg(II) by 3.6 times compared to the natural zeolite. The leaching test indicated the retention of Hg(II) in the zeolite structure over a wide pH range, making this sulfur-impregnated sorbent a promising material for the remediation of a mercury-polluted environment.

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

Biomolecules ◽

10.3390/biom10040509 ◽

2020 ◽

Vol 10 (4) ◽

pp. 509 ◽

Cited By ~ 2

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.

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Magnetically Recyclable Wool Keratin Modified Magnetite Powders for Efficient Removal of Cu2+ Ions from Aqueous Solutions

Nanomaterials ◽

10.3390/nano11051068 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1068

Author(s):

Xinyue Zhang ◽

Yani Guo ◽

Wenjun Li ◽

Jinyuan Zhang ◽

Hailiang Wu ◽

...

Keyword(s):

Electron Microscopy ◽

Aqueous Solutions ◽

Adsorption Capacity ◽

Surface Area ◽

Ion Concentration ◽

Bet Surface Area ◽

Chemical Compositions ◽

Ion Adsorption ◽

X Ray ◽

Wool Keratin

The treatment of wastewater containing heavy metals and the utilization of wool waste are very important for the sustainable development of textile mills. In this study, the wool keratin modified magnetite (Fe3O4) powders were fabricated by using wool waste via a co-precipitation technique for removal of Cu2+ ions from aqueous solutions. The morphology, chemical compositions, crystal structure, microstructure, magnetism properties, organic content, and specific surface area of as-fabricated powders were systematically characterized by various techniques including field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), thermogravimetric (TG) analysis, and Brunauer–Emmett–Teller (BET) surface area analyzer. The effects of experimental parameters such as the volume of wool keratin hydrolysate, the dosage of powder, the initial Cu2+ ion concentration, and the pH value of solution on the adsorption capacity of Cu2+ ions by the powders were examined. The experimental results indicated that the Cu2+ ion adsorption performance of the wool keratin modified Fe3O4 powders exhibited much better than that of the chitosan modified ones with a maximum Cu2+ adsorption capacity of 27.4 mg/g under favorable conditions (0.05 g powders; 50 mL of 40 mg/L CuSO4; pH 5; temperature 293 K). The high adsorption capacity towards Cu2+ ions on the wool keratin modified Fe3O4 powders was primarily because of the strong surface complexation of –COOH and –NH2 functional groups of wool keratins with Cu2+ ions. The Cu2+ ion adsorption process on the wool keratin modified Fe3O4 powders followed the Temkin adsorption isotherm model and the intraparticle diffusion and pseudo-second-order adsorption kinetic models. After Cu2+ ion removal, the wool keratin modified Fe3O4 powders were easily separated using a magnet from aqueous solution and efficiently regenerated using 0.5 M ethylene diamine tetraacetic acid (EDTA)-H2SO4 eluting. The wool keratin modified Fe3O4 powders possessed good regenerative performance after five cycles. This study provided a feasible way to utilize waste wool textiles for preparing magnetic biomass-based adsorbents for the removal of heavy metal ions from aqueous solutions.

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Physico-Chemical and Morphological Changes of Sayong Kaolinite Clay Treated with Sulphuric Acid for Enzyme Immobilization

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.832.589 ◽

2013 ◽

Vol 832 ◽

pp. 589-595 ◽

Cited By ~ 1

Author(s):

N.A. Edama ◽

A. Sulaiman ◽

K.H. Ku Hamid ◽

M.N. Muhd Rodhi ◽

Mohibah Musa ◽

...

Keyword(s):

Surface Area ◽

Sulphuric Acid ◽

Enzyme Immobilization ◽

Morphological Changes ◽

Chemical Properties ◽

X Ray Diffraction ◽

Kaolinite Clay ◽

X Ray ◽

Mineral Oxides ◽

Physico Chemical

This study analyzed the effects of sulphuric acid (H2SO4) treatment on pysico-chemical properties and morphological changes of clay obtained from Sg. Sayong, Perak. The clay was ground and sieved to <150μm and treated with different concentrations of H2SO4. The treatment was completed by refluxing the clay with different concentration of H2SO4 (1M, 5M and 10M ) at 100 °C for 4 hours and followed by calcination at 500 °C for 1 hour. The physic-chemical properties and morphological changes of the untreated and treated clay were compared using Surface Area Analyser, X-Ray Diffraction (XRD), Field Emission Scanning Electron Micrograph (FESEM), X-Ray Diffraction (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR). The results showed that acid treatment of 5M increased the surface area from 25 m2/g to 75 m2/g and the pore volume increased from 0.1518 cc/g to 0.3546 cc/g. The nanopore size of the clay decreased from 24.8 nm to 19.4 nm after treated with acid. This can be explained due to the elimination of the exchangeable cations and generation of microporosity. The results of XRF showed SiO2 increased from 58.34% to 74.52% and Al2O3 reduced from 34.6% to 18.31%. The mineral oxides such as Fe2O3, MgO, CaO, K2O and TiO2 also reduced. This concluded that H2SO4 treatment has led to significant removal of octahedral Al3+, Fe3+ cations and other impurities. In conclusion, this study showed the physico-chemical properties and morphology of Sayong clay were improved once treated with H2SO4 and therefore suggests better supporting material for enzyme immobilization.

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

Microscopy and Microanalysis ◽

10.1017/s1431927696210530 ◽

1996 ◽

Vol 2 (2) ◽

pp. 53-62 ◽

Cited By ~ 3

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.

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Synthesis and Characterization of Hematite Nanoparticles as Active Photocatalyst for Water Splitting Application

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.594-595.73 ◽

2013 ◽

Vol 594-595 ◽

pp. 73-77 ◽

Cited By ~ 1

Author(s):

Sze Mei Chin ◽

Suriati Sufian ◽

Jeefferie Abd Razak

Keyword(s):

Surface Area ◽

Water Splitting ◽

Combustion Method ◽

Hydrogen Gas ◽

Bet Surface Area ◽

Synthesis And Characterization ◽

Hematite Nanoparticles ◽

X Ray ◽

Bet Specific Surface Area

This paper highlights on the hydrogen production through photocatalytic activity by using hematite nanoparticles synthesized from self-combustion method based on different stirring period. The morphologies and microstructures of the nanostructures were determined using Field-Emission Scanning Electron Microscope (FESEM), X-Ray Diffractometer (XRD) and Particle Size Analyser (PSA). Besides that, surface area analyser was used to determine the BET surface area of the hematite samples. The hematite nanocatalyst as-synthesized are proven to be rhombohedral crystalline hematite (α-Fe2O3) with particle diameters ranging from 60-140 nm. The BET specific surface area of hematite samples increased from 5.437 to 7.6425 m2/g with increasing stirring period from 1 to 4 weeks. This caused the amount of hydrogen gas produced from photocatalytic water splitting to increase as well.

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

Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment ◽

10.1016/s0168-9002(02)01612-1 ◽

2002 ◽

Vol 495 (3) ◽

pp. 232-239 ◽

Cited By ~ 2

Author(s):

H Awaki ◽

K Tachibana ◽

Y Tamai ◽

K Yamamoto ◽

S Kitamoto ◽

...

Keyword(s):

Depletion Layer ◽

X Ray ◽

Novel Method

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Hydrothermal Treatment of Coprecipitated YSZ Powders

Materials Science Forum ◽

10.4028/www.scientific.net/msf.660-661.983 ◽

2010 ◽

Vol 660-661 ◽

pp. 983-988 ◽

Cited By ~ 2

Author(s):

Alexander Rodrigo Arakaki ◽

Walter Kenji Yoshito ◽

Valter Ussui ◽

Dolores Ribeiro Ricci Lazar

Keyword(s):

Surface Area ◽

Hydrothermal Treatment ◽

Gas Adsorption ◽

X Ray Diffraction ◽

Electronic Microscopy ◽

Immersion Method ◽

Cubic Symmetry ◽

X Ray ◽

Granulometric Analysis ◽

Symmetry Surface

Zirconia stabilized with 8.5 mol% yttria (YSZ) were synthesized by coprecipitation and resulting gels were hydrothermallly treated at 200°C and 220 PSI for 4, 8 and 16 hours. Products were oven dried at 70°C for 24 hours, isostatically pressed as pellets and sintered at 1500 °C for 1 hour. Powders were characterized for surface area with N2 gas adsorption, X-ray diffraction, laser diffraction granulometric analysis and scanning and transmission electronic microscopy. Density of ceramics was measured by an immersion method based on the Archimedes principle. Results showed that powders dried at 70°C are amorphous and after treatment has tetragonal/cubic symmetry. Surface area of powders presented a significant reduction after hydrothermal treatment. Ceramics prepared from hydrothermally treated powders have higher green density but sintered pellets are less dense when compared to that made with powders calcined at 800°C for 1 hour due to the agglomerate state of powders. Solvothermal treatment is a promising procedure to enhance density.

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