Enhanced Grain-boundary Emission Lifetime and Additive Induced Crystal Orientation in One-Step Spin-Coated Mixed Cationic (FA/MA) Lead Perovskite Thin Films Stabilized by Zinc Iodide Doping

Mixed cationic lead perovskites containing formamidinium and methylammonium can be stabilized by incorporating ZnI<sub>2 </sub>as an “internal desiccant”. Next to prolonged stability under ambient conditions we show with XRD that the use of an additive, 3-chloropropyl ammonium chloride, influences crystal formation by orienting the crystals. These ~500 nm crystals show individual photoluminescent behavior in thin films and have a longer photoluminescence lifetime at the grain boundaries as compared to the center of the crystal or relative to un-doped materials without the additive made under identical conditions. Charges recombine slower at the edges of the crystals as observed with confocal laser scanning microscopy. The material can also be prepared as a black precursor powder by a solid-solid reaction under ambient conditions.

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Enhanced Grain-boundary Emission Lifetime and Additive Induced Crystal Orientation in One-Step Spin-Coated Mixed Cationic (FA/MA) Lead Perovskite Thin Films Stabilized by Zinc Iodide Doping

10.26434/chemrxiv.5484073 ◽

2017 ◽

Author(s):

Loreta A. Muscarella ◽

Dina Petrova ◽

Rebecca Jorge Cervasio ◽

Aram Farawar ◽

Olivier Lugier ◽

...

Keyword(s):

Thin Films ◽

Laser Scanning ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Crystal Formation ◽

Ambient Conditions ◽

Emission Lifetime ◽

Photoluminescence Lifetime ◽

One Step ◽

Zinc Iodide

Mixed cationic lead perovskites containing formamidinium and methylammonium can be stabilized by incorporating ZnI<sub>2 </sub>as an “internal desiccant”. Next to prolonged stability under ambient conditions we show with XRD that the use of an additive, 3-chloropropyl ammonium chloride, influences crystal formation by orienting the crystals. These ~500 nm crystals show individual photoluminescent behavior in thin films and have a longer photoluminescence lifetime at the grain boundaries as compared to the center of the crystal or relative to un-doped materials without the additive made under identical conditions. Charges recombine slower at the edges of the crystals as observed with confocal laser scanning microscopy. The material can also be prepared as a black precursor powder by a solid-solid reaction under ambient conditions.

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One-step preparation of antimicrobial silicone materials based on PDMS and salicylic acid: insights from spatially and temporally resolved techniques

npj Biofilms and Microbiomes ◽

10.1038/s41522-021-00223-6 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Luca Barbieri ◽

Ioritz Sorzabal Bellido ◽

Alison J. Beckett ◽

Ian A. Prior ◽

Jo Fothergill ◽

...

Keyword(s):

Salicylic Acid ◽

Laser Scanning ◽

Pathogenic Bacteria ◽

Pharmaceutical Products ◽

Laser Scanning Microscopy ◽

Wound Dressings ◽

Confocal Laser ◽

Vis Spectroscopy ◽

Wide Range ◽

One Step

AbstractIn this work, we introduce a one-step strategy that is suitable for continuous flow manufacturing of antimicrobial PDMS materials. The process is based on the intrinsic capacity of PDMS to react to certain organic solvents, which enables the incorporation of antimicrobial actives such as salicylic acid (SA), which has been approved for use in humans within pharmaceutical products. By combining different spectroscopic and imaging techniques, we show that the surface properties of PDMS remain unaffected while high doses of the SA are loaded inside the PDMS matrix. The SA can be subsequently released under physiological conditions, delivering a strong antibacterial activity. Furthermore, encapsulation of SA inside the PDMS matrix ensured a diffusion-controlled release that was tracked by spatially resolved Raman spectroscopy, Attenuated Total Reflectance IR (ATR-IR), and UV-Vis spectroscopy. The biological activity of the new material was evaluated directly at the surface and in the planktonic state against model pathogenic bacteria, combining confocal laser scanning microscopy, electron microscopy, and cell viability assays. The results showed complete planktonic inhibition for clinically relevant strains of Staphylococcus aureus and Escherichia coli, and a reduction of up to 4 orders of magnitude for viable sessile cells, demonstrating the efficacy of these surfaces in preventing the initial stages of biofilm formation. Our approach adds a new option to existing strategies for the antimicrobial functionalisation of a wide range of products such as catheters, wound dressings and in-dwelling medical devices based on PDMS.

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The Effect of Thermocycling on Interfacial Bonding Stability of Self-Etch Adhesives: OCT Study

BioMed Research International ◽

10.1155/2021/5578539 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

T. A. Bakhsh ◽

A. Turkistani

Keyword(s):

Laser Scanning ◽

Adhesive System ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Gap Formation ◽

Swept Source ◽

Before And After ◽

One Step ◽

Self Etch ◽

Filled Composite

Objective. The aim of this study was to monitor the behavior of interfacial gaps formed under different bonded polymeric restorations before and after thermocycling (TC), using swept-source optical coherence tomography (SS-OCT) and confirming the obtained findings with confocal laser scanning microscopy (CLSM). Materials and Methods. Cylindrical class I cavities were prepared in twenty noncarious human premolar teeth ( 1.5 mm depth × 3.5 mm diameter ) and divided randomly into two groups: TS and SN, according to the adhesive system ( n = 10 ). In the TS group, one-step self-etch adhesive Clearfil Tri-S Bond Plus (Kuraray Noritake Dental, Japan) was used, followed by composite restoration using Estelite Sigma Quick (Tokuyama Dental, Japan). In the SN group, the cavities were restored with the two-step self-etch/composite silorane-based resin restoration system (3M ESPE, USA). All specimens were restored in bulk filling technique and cured in accordance with the manufacturers’ instructions. Both groups were imaged under SS-OCT after 24 h and recorded as controls. Then, each group was subjected to thermal challenge using the TC machine (5–55°C) and B-scans were recorded at different TC intervals (2600, 5200, and 10000). In order to confirm the SS-OCT findings, additional specimens were prepared, scanned, and sectioned for CLSM observation. Results. B-scans demonstrated white clusters at the tooth-resin interface that corresponded to the gap location on CLSM images. The TS group showed significantly less gap formation than the SN group before and after TC ( p < 0.001 ). Conclusions. An optimal composite adaptation can be achieved when the bonded restoration comprises a combination of an adhesive containing 10-MDP monomer and a considerable highly filled composite.

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Effects of Natural Radiation, Photosynthetically Active Radiation and Artificial Ultraviolet Radiation-B on the Chloroplast Organization and Metabolism ofPorphyra acanthophoravar.brasiliensis(Rhodophyta, Bangiales)

Microscopy and Microanalysis ◽

10.1017/s1431927612013359 ◽

2012 ◽

Vol 18 (6) ◽

pp. 1467-1479 ◽

Cited By ~ 14

Author(s):

Zenilda L. Bouzon ◽

Fungyi Chow ◽

Carmen S. Zitta ◽

Rodrigo W. dos Santos ◽

Luciane C. Ouriques ◽

...

Keyword(s):

Ultraviolet Radiation ◽

Photosynthetically Active Radiation ◽

Laser Scanning ◽

Reductase Activity ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Ambient Conditions ◽

Natural Radiation ◽

Active Radiation ◽

Ultraviolet Radiation B

AbstractWe undertook a study ofPorphyra acanthophoravar.brasiliensisto determine its responses under ambient conditions, photosynthetically active radiation (PAR), and PAR+UVBR (ultraviolet radiation-B) treatment, focusing on changes in ultrastructure, and cytochemistry. Accordingly, control ambient samples were collected in the field, and two different treatments were performed in the laboratory. Plants were exposed to PAR at 60 μmol photons m−2s−1and PAR + UVBR at 0.35 W m−2for 3 h per day during 21 days ofin vitrocultivation. Confocal laser scanning microscopy analysis of the vegetative cells showed single stellate chloroplast in ambient and PAR samples, but in PAR+UVBR-exposed plants, the chloroplast showed alterations in the number and form of arms. Under PAR+UVBR treatment, the thylakoids of the chloroplasts were disrupted, and an increase in the number of plastoglobuli was observed, in addition to mitochondria, which appeared with irregular, disrupted morphology compared to ambient and PAR samples. After UVBR exposure, the formation of carpospores was also observed. Plants under ambient conditions, as well as those treated with PAR and PAR+UVBR, all showed different concentrations of enzymatic response, including glutathione peroxidase and reductase activity. In summary, the present study demonstrates thatP. acanthophoravar.brasiliensisshows the activation of distinct mechanisms against natural radiation, PAR and PAR+UVBR.

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Templating the morphology of soft microgel assemblies using a nanolithographic 3D-printed membrane

Scientific Reports ◽

10.1038/s41598-020-80324-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

John Linkhorst ◽

Jonas Lölsberg ◽

Sebastian Thill ◽

Johannes Lohaus ◽

Arne Lüken ◽

...

Keyword(s):

Laser Scanning ◽

Membrane Separation ◽

Colloidal Crystal ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Crystal Formation ◽

Separation Processes ◽

Compaction Behavior ◽

Optical Visualization ◽

Filter Cakes

AbstractFilter cake formation is the predominant phenomenon limiting the filtration performance of membrane separation processes. However, the filter cake’s behavior at the particle scale, which determines its overall cake behavior, has only recently come into the focus of scientists, leaving open questions about its formation and filtration behavior. The present study contributes to the fundamental understanding of soft filter cakes by analyzing the influence of the porous membrane’s morphology on crystal formation and the compaction behavior of soft filter cakes under filtration conditions. Microfluidic chips with nanolithographic imprinted filter templates were used to trigger the formation of crystalline colloidal filter cakes formed by soft microgels. The soft filter cakes were observed via confocal laser scanning microscopy (CLSM) under dead-end filtration conditions. Colloidal crystal formation in the cake, as well as their compaction behavior, were analyzed by optical visualization and pressure data. For the first time, we show that exposing the soft cake to a crystalline filter template promotes the formation of colloidal crystallites and that soft cakes experience gradient compression during filtration.

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3-D imaging of cells using a confocal laser scanning microscope and digital image processing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100102560 ◽

1988 ◽

Vol 46 ◽

pp. 96-97

Author(s):

Thomas M. Jovin ◽

Michel Robert-Nicoud ◽

Donna J. Arndt-Jovin ◽

Thorsten Schormann

Keyword(s):

Laser Scanning ◽

Confocal Laser Scanning Microscope ◽

Laser Scanning Microscopy ◽

Confocal Laser Scanning ◽

Confocal Laser ◽

Scanning Microscope ◽

Laser Scanning Microscope ◽

Biochemical Processes ◽

Adjacent Structures

Light microscopic techniques for visualizing biomolecules and biochemical processes in situ have become indispensable in studies concerning the structural organization of supramolecular assemblies in cells and of processes during the cell cycle, transformation, differentiation, and development. Confocal laser scanning microscopy offers a number of advantages for the in situ localization and quantitation of fluorescence labeled targets and probes: (i) rejection of interfering signals emanating from out-of-focus and adjacent structures, allowing the “optical sectioning” of the specimen and 3-D reconstruction without time consuming deconvolution; (ii) increased spatial resolution; (iii) electronic control of contrast and magnification; (iv) simultanous imaging of the specimen by optical phenomena based on incident, scattered, emitted, and transmitted light; and (v) simultanous use of different fluorescent probes and types of detectors.We currently use a confocal laser scanning microscope CLSM (Zeiss, Oberkochen) equipped with 3-laser excitation (u.v - visible) and confocal optics in the fluorescence mode, as well as a computer-controlled X-Y-Z scanning stage with 0.1 μ resolution.

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Vacuoles Induced in Mammalian Cells by Helicobacter Cytotoxin are Acidic Organelles

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100158388 ◽

1990 ◽

Vol 48 (3) ◽

pp. 168-169

Author(s):

M. H. Chestnut ◽

C. E. Catrenich

Keyword(s):

Acridine Orange ◽

Mammalian Cells ◽

Laser Scanning ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Ulcer Disease ◽

Gastroduodenal Disease ◽

H Pylori

Helicobacter pylori is a non-invasive, Gram-negative spiral bacterium first identified in 1983, and subsequently implicated in the pathogenesis of gastroduodenal disease including gastritis and peptic ulcer disease. Cytotoxic activity, manifested by intracytoplasmic vacuolation of mammalian cells in vitro, was identified in 55% of H. pylori strains examined. The vacuoles increase in number and size during extended incubation, resulting in vacuolar and cellular degeneration after 24 h to 48 h. Vacuolation of gastric epithelial cells is also observed in vivo during infection by H. pylori. A high molecular weight, heat labile protein is believed to be responsible for vacuolation and to significantly contribute to the development of gastroduodenal disease in humans. The mechanism by which the cytotoxin exerts its effect is unknown, as is the intracellular origin of the vacuolar membrane and contents. Acridine orange is a membrane-permeant weak base that initially accumulates in low-pH compartments. We have used acridine orange accumulation in conjunction with confocal laser scanning microscopy of toxin-treated cells to begin probing the nature and origin of these vacuoles.

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