Precision size and refractive index analysis of weakly scattering nanoparticles in polydispersions.

Characterization of the size and material properties of particles in liquid suspensions is in very high demand, e.g., for the analysis of colloidal samples or of bodily fluids such as urine or blood plasma. However, the existing methods are limited in deciphering the constituents of realistic samples. Here, we introduce iNTA as a new method, which combines interferometric detection of scattering with nanoparticle tracking analysis, to reach an unprecedented sensitivity and precision in determining the size and refractive index distributions of nanoparticles in suspensions. After benchmarking iNTA with samples of colloidal gold, we present its remarkable ability to resolve the constituents of various multi-component and polydisperse samples of known origin. Furthermore, we showcase the method by elucidating the refractive index and size distributions of extracellular vesicles from Leishmania parasites and nanoparticles in human urine. The current performance of iNTA already enables advances in several important applications, but we also discuss possible improvements.

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TEM characterization of proton-exchanged LiNbO3 optical waveguides

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010014395x ◽

1986 ◽

Vol 44 ◽

pp. 480-481

Author(s):

W. E. Lee

Keyword(s):

Refractive Index ◽

Benzoic Acid ◽

Optical Waveguides ◽

Total Internal Reflection ◽

Index Of Refraction ◽

Optical Measurements ◽

Lithium Ions ◽

Wide Channel ◽

Tem Characterization

An optical waveguide consists of a several-micron wide channel with a slightly different index of refraction than the host substrate; light can be trapped in the channel by total internal reflection.Optical waveguides can be formed from single-crystal LiNbO3 using the proton exhange technique. In this technique, polished specimens are masked with polycrystal1ine chromium in such a way as to leave 3-13 μm wide channels. These are held in benzoic acid at 249°C for 5 minutes allowing protons to exchange for lithium ions within the channels causing an increase in the refractive index of the channel and creating the waveguide. Unfortunately, optical measurements often reveal a loss in waveguiding ability up to several weeks after exchange.

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Preparation and Characterization of Polyvinylidene Fluoride/ZrO2-TiO2 Optical Film with Wide Band Gap and High Refractive Index

Journal of Inorganic Materials ◽

10.3724/sp.j.1077.2013.12747 ◽

2013 ◽

Vol 28 (6) ◽

pp. 671-676 ◽

Cited By ~ 4

Author(s):

Yu-Qing ZHANG ◽

Li-Li ZHAO ◽

Shi-Long XU ◽

Chao ZHANG ◽

Xiao-Ying CHEN ◽

...

Keyword(s):

Refractive Index ◽

Band Gap ◽

Polyvinylidene Fluoride ◽

Wide Band ◽

High Refractive Index ◽

Wide Band Gap ◽

Optical Film

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CHARACTERIZATION OF PORE SIZE DISTRIBUTIONS USING NON-NEWTONIAN FLUIDS

10.1130/abs/2020cd-347260 ◽

2020 ◽

Author(s):

Scott C. Hauswirth ◽

◽

Majdi Abou Najm ◽

Christelle Basset

Keyword(s):

Pore Size ◽

Newtonian Fluids ◽

Size Distributions ◽

Pore Size Distributions

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Isolation and Molecular Typing of Leishmania infantum from Phlebotomus perfiliewi in a Re-Emerging Focus of Leishmaniasis, Northeastern Italy

Microorganisms ◽

10.3390/microorganisms7120644 ◽

2019 ◽

Vol 7 (12) ◽

pp. 644

Author(s):

Mattia Calzolari ◽

Elena Carra ◽

Gianluca Rugna ◽

Paolo Bonilauri ◽

Federica Bergamini ◽

...

Keyword(s):

Leishmania Infection ◽

Sand Flies ◽

Repetitive Region ◽

Microsatellite Typing ◽

Increasing Trend ◽

Northeastern Italy ◽

Emilia Romagna Region ◽

Phlebotomus Perfiliewi ◽

Leishmania Parasites

Visceral leishmaniasis (VL) caused by Leishmania (L.) infantum is a public health threat in the Emilia-Romagna region, northeastern Italy, but its epidemiology has not been fully elucidated in this area. The objective of this study was to characterize Leishmania infection in sand flies collected in a re-emerging focus of VL in the Bologna province. During the summer of 2016, 6114 sand flies were collected, identified, and tested for Leishmania detection. Of the identified sand flies, 96.5% were Phlebotomus (P.) perfiliewi and 3.5% were P. perniciosus. Detected parasites were characterized by biomolecular methods (multilocus microsatellite typing and characterization of repetitive region on chromosome 31), and quantified by real-time PCR. The prevalence of Leishmania infection in individually-tested P. perfiliewi sand flies varied from 6% to 10% with an increasing trend during the season. Promastigotes of L. infantum were isolated by dissection in one P. perfiliewi female; the isolated strain (Lein-pw) were closely related to Leishmania parasites from VL cases in northeastern Italy, but differed from strains isolated in dogs from the same area. Our findings strongly support the vector status of P. perfiliewi for human VL in the study area.

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Ionized gas kinematics and luminosity profiles of Low-z Lyman Alpha Blobs

Proceedings of the International Astronomical Union ◽

10.1017/s1743921320001489 ◽

2019 ◽

Vol 15 (S359) ◽

pp. 413-414

Author(s):

María P. Agüero ◽

Rubén Díaz ◽

Mischa Schirmer

Keyword(s):

Emission Line ◽

Galactic Nuclei ◽

Host Galaxies ◽

Ionized Gas ◽

Lyman Alpha ◽

Gas Kinematics ◽

The Universe ◽

Very High ◽

The Continuum

AbstractThis work is focused on the characterization of the Seyfert-2 galaxies hosting very large, ultra-luminous narrow-line regions (NLRs) at redshifts z = 0.2−0.34. With a space density of 4.4 Gcp−3 at z ∼ 0.3, these “Low Redshift Lyman-α Blob” (LAB) host galaxies are amongst the rarest objects in the universe, and represent an exceptional and short-lived phenomenon in the life cycle of active galactic nuclei (AGNs). We present the study of GMOS spectra for 13 LAB galaxies covering the rest frame spectral range 3700–6700 Å. Predominantly, the [OIII]λ5007 emission line radial distribution is as widespread as that of the continuum one. The emission line profiles exhibit FWHM between 300–700 Km s−1. In 7 of 13 cases a broad kinematical component is detected with FWHM within the range 600–1100 Km s−1. The exceptionally high [OIII]λ5007 luminosity is responsible for very high equivalent width reaching 1500 Å at the nucleus.

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Ultrasonic Time-of-Flight Computed Tomography for Investigation of Batch Crystallisation Processes

Sensors ◽

10.3390/s21020639 ◽

2021 ◽

Vol 21 (2) ◽

pp. 639

Author(s):

Panagiotis Koulountzios ◽

Tomasz Rymarczyk ◽

Manuchehr Soleimani

Keyword(s):

Spatial Information ◽

Injection Rate ◽

Ultrasound Tomography ◽

Measurement Systems ◽

Process Dynamics ◽

Tomography System ◽

Ultrasonic Time ◽

Crystallisation Process ◽

Liquid Suspensions

Crystallisation is a crucial step in many industrial processes. Many sensors are being investigated for monitoring such processes to enhance the efficiency of them. Ultrasound techniques have been used for particle sizing characterization of liquid suspensions, in crystallisation process. An ultrasound tomography system with an array of ultrasound sensors can provide spatial information inside the process when compared to single-measurement systems. In this study, the batch crystallisation experiments have been conducted in a lab-scale reactor in calcium carbonate crystallisation. Real-time ultrasound tomographic imaging is done via a contactless ultrasound tomography sensor array. The effect of the injection rate and the stirring speed was considered as two control parameters in these crystallisation functions. Transmission mode ultrasound tomography comprises 32 piezoelectric transducers with central frequency of 40 kHz has been used. The process-based experimental investigation shows the capability of the proposed ultrasound tomography system for crystallisation process monitoring. Information on process dynamics, as well as process malfunction, can be obtained via the ultrasound tomography system.

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Size-resolved characterization of organic aerosol in the North China Plain: new insights from high resolution spectral analysis

Environmental Science: Atmospheres ◽

10.1039/d1ea00025j ◽

2021 ◽

Author(s):

Weiqi Xu ◽

Chun Chen ◽

Yanmei Qiu ◽

Conghui Xie ◽

Yunle Chen ◽

...

Keyword(s):

Radiative Forcing ◽

North China Plain ◽

North China ◽

Fine Particles ◽

Large Fraction ◽

Organic Aerosol ◽

Size Distributions ◽

The North ◽

The Impact

Organic aerosol (OA), a large fraction of fine particles, has a large impact on climate radiative forcing and human health, and the impact depends strongly on size distributions. Here we...

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Halogenated Volatile Organic Compounds in Water Samples and Inorganic Elements Levels in Ores for Characterizing a High Anthropogenic Polluted Area in the Northern Latium Region (Italy)

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18041628 ◽

2021 ◽

Vol 18 (4) ◽

pp. 1628

Author(s):

Mario Vincenzo Russo ◽

Ivan Notardonato ◽

Alberto Rosada ◽

Giuseppe Ianiri ◽

Pasquale Avino

Keyword(s):

Organic Compounds ◽

Mean Value ◽

Greenhouse Crops ◽

River Waters ◽

Liquid Liquid Extraction ◽

Volatile Organic ◽

High Concentrations ◽

Very High ◽

Inorganic Fraction

This paper shows a characterization of the organic and inorganic fraction of river waters (Tiber and Marta) and ores/soil samples collected in the Northern Latium region of Italy for evaluating the anthropogenic/natural source contribution to the environmental pollution of this area. For organic compounds, organochloride volatile compounds in Tiber and Marta rivers were analyzed by two different clean-up methods (i.e., liquid–liquid extraction and static headspace) followed by gas chromatography–electron capture detector (GC-ECD) analysis. The results show very high concentrations of bromoform (up to 1.82 and 3.2 µg L−1 in Tiber and Marta rivers, respectively), due to the presence of greenhouse crops, and of chloroform and tetrachloroethene, due to the presence of handicrafts installations. For the qualitative and quantitative assessment of the inorganic fraction, it is highlighted the use of a nuclear analytical method, instrumental neutron activation analysis, which allows having more information as possible from the sample without performing any chemical-physical pretreatment. The results have evidenced high levels of mercury (mean value 88.6 µg g−1), antimony (77.7 µg g−1), strontium (12,039 µg g−1) and zinc (103 µg g−1), whereas rare earth elements show levels similar to the literature data. Particular consideration is drawn for arsenic (414 µg g−1): the levels found in this paper (ranging between 1 and 5100 µg g−1) explain the high content of such element (as arsenates) in the aquifer, a big issue in this area.

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Equilibrium, Thermodynamic, Reuse, and Selectivity Studies for the Bioadsorption of Lanthanum onto Sericin/Alginate/Poly(vinyl alcohol) Particles

Polymers ◽

10.3390/polym13040623 ◽

2021 ◽

Vol 13 (4) ◽

pp. 623

Author(s):

Talles Barcelos da Costa ◽

Meuris Gurgel Carlos da Silva ◽

Melissa Gurgel Adeodato Vieira

Keyword(s):

Vinyl Alcohol ◽

Economic Value ◽

Poly Vinyl Alcohol ◽

Thermodynamic Quantities ◽

High Demand ◽

Batch System ◽

Equilibrium Data ◽

Selectivity Studies ◽

Amorphous Character

In a scenario of high demand, low availability, and high economic value, the recovery of rare-earth metals from wastewater is economically and environmentally attractive. Bioadsorption is a promising method as it offers simple design and operation. The aim of this study was to investigate lanthanum bioadsorption using a polymeric bioadsorbent of sericin/alginate/poly(vinyl alcohol)-based biocomposite. Batch system assays were performed to evaluate the equilibrium, thermodynamics, regeneration, and selectivity of bioadsorption. The maximum capture amount of lanthanum at equilibrium was 0.644 mmol/g at 328 K. The experimental equilibrium data were better fitted by Langmuir and Dubinin–Radushkevich isotherms. Ion exchange mechanism between calcium and lanthanum (2:3 ratio) was confirmed by bioadsorption isotherms. Thermodynamic quantities showed that the process of lanthanum bioadsorption was spontaneous (−17.586, −19.244, and −20.902 kJ/mol), endothermic (+15.372 kJ/mol), and governed by entropic changes (+110.543 J/mol·K). The reusability of particles was achieved using 0.1 mol/L HNO3/Ca(NO3)2 solution for up to five regeneration cycles. The bioadsorbent selectivity followed the order of lanthanum > cadmium > zinc > nickel. Additionally, characterization of the biocomposite prior to and post lanthanum bioadsorption showed low porosity (9.95 and 12.35%), low specific surface area (0.054 and 0.019 m2/g), amorphous character, and thermal stability at temperatures up to 473 K. This study shows that sericin/ alginate/poly(vinyl alcohol)-based biocomposites are effective in the removal and recovery of lanthanum from water.

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Expression and Characterization of the Flocculin Flo11/Muc1, a Saccharomyces cerevisiae Mannoprotein with Homotypic Properties of Adhesion

Eukaryotic Cell ◽

10.1128/ec.00284-06 ◽

2007 ◽

Vol 6 (12) ◽

pp. 2214-2221 ◽

Cited By ~ 53

Author(s):

Lois M. Douglas ◽

Li Li ◽

Yang Yang ◽

A. M. Dranginis

Keyword(s):

Saccharomyces Cerevisiae ◽

Biofilm Formation ◽

In Vitro System ◽

Glycosylphosphatidylinositol Anchor ◽

Fungal Adhesion ◽

Very High ◽

Molecular Weight Form

ABSTRACT The Flo11/Muc1 flocculin has diverse phenotypic effects. Saccharomyces cerevisiae cells of strain background Σ1278b require Flo11p to form pseudohyphae, invade agar, adhere to plastic, and develop biofilms, but they do not flocculate. We show that S. cerevisiae var. diastaticus strains, on the other hand, exhibit Flo11-dependent flocculation and biofilm formation but do not invade agar or form pseudohyphae. In order to study the nature of the Flo11p proteins produced by these two types of strains, we examined secreted Flo11p, encoded by a plasmid-borne gene, in which the glycosylphosphatidylinositol anchor sequences had been replaced by a histidine tag. A protein of approximately 196 kDa was secreted from both strains, which upon purification and concentration, aggregated into a form with a very high molecular mass. When secreted Flo11p was covalently attached to microscopic beads, it conferred the ability to specifically bind to S. cerevisiae var. diastaticus cells, which flocculate, but not to Σ1278b cells, which do not flocculate. This was true for the 196-kDa form as well as the high-molecular-weight form of Flo11p, regardless of the strain source. The coated beads bound to S. cerevisiae var. diastaticus cells expressing FLO11 and failed to bind to cells with a deletion of FLO11, demonstrating a homotypic adhesive mechanism. Flo11p was shown to be a mannoprotein. Bead-to-cell adhesion was inhibited by mannose, which also inhibits Flo11-dependent flocculation in vivo, further suggesting that this in vitro system is a useful model for the study of fungal adhesion.

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