scholarly journals New insights into the blue intrinsic fluorescence of oxidized PAMAM dendrimers considering their use as bionanomaterials

2020 ◽  
Vol 8 (45) ◽  
pp. 10314-10326
Author(s):  
Cláudia S. Camacho ◽  
Marta Urgellés ◽  
Helena Tomás ◽  
Fernando Lahoz ◽  
João Rodrigues
Keyword(s):  
Fluorescence Intensity ◽  
Pamam Dendrimers ◽  
Intrinsic Fluorescence ◽  
Acidic Environment ◽  
Dendrimer Generation

The fluorescence intensity of oxidized PAMAM dendrimers is not only dependent on the number of HASLs in the dendrimer scaffold (i.e., on dendrimer generation), but also on the rigidification suffered by the dendrimer due to the acidic environment.

scholarly journals Effects of Glazing with Preservatives on the Quality Changes of Squid during Frozen Storage

2019 ◽  
Vol 9 (18) ◽  
pp. 3847 ◽  
Author(s):  
Mingtang Tan ◽  
Peiyun Li ◽  
Wenhui Yu ◽  
Jinfeng Wang ◽  
Jing Xie
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Shelf Life ◽  
Fluorescence Intensity ◽  
Frozen Storage ◽  
Intrinsic Fluorescence ◽  
Quality Changes ◽  
Low Field ◽  
Lf Nmr

This study aimed to investigate the effects of glazing with sodium polyacrylate (SP) and D-sodium erythorbate (DSE) on the quality changes of squid during frozen storage. Frozen squid samples were randomly divided into seven groups: (1) CK (unglazed); (2) WG (distilled water-glazed); (3) SG (0.1% SP -glazed); (4) SG-1DSE (0.1% SP with 0.1% DSE -glazed); (5) SG-3DSE (0.1% SP with 0.3% DSE-glazed); (6) SG-5DSE (0.1% SP with 0.5% DSE-glazed); (7) WG-1DSE (0.1% DSE-glazed). The efficacy of the different coatings was evaluated using various indicators, such as water holding capacity (WHC), pH value, low field nuclear magnetic resonance (LF-NMR), color, malondialdehyde (MDA) content value, free amino acids (FAAs) content, intrinsic fluorescence intensity (IFI) and the total sulfhydryl content (SH) content. Intrinsic fluorescence intensity (IFI) and low field nuclear magnetic resonance (LF-NMR) were used as fast monitoring techniques to monitor changes in quality of squid samples. The results showed that compared with the CK and WG groups, coating with either SG or DSE alone resulted in reduced rate of moisture loss (p < 0.05), lipid oxidation (p < 0.05) protein degradation (p < 0.05) and prolonged its shelf-life. The combination of glazing treatment with SG and DSE (groups SG-1DSE, SG-3DSE and SG-5DSE) further improved the protective effects of coating, particularly in the SG-3DSE group. Therefore, the glazing of SG-3DSE is recommended to be used to control the quality of frozen squid and to prolong its shelf-life during frozen storage.

scholarly journals The Characteristics of Intrinsic Fluorescence of Type I Collagen Influenced by Collagenase I

2018 ◽  
Vol 8 (10) ◽  
pp. 1947 ◽  
Author(s):  
Yiming Shen ◽  
Deyi Zhu ◽  
Wenhui Lu ◽  
Bing Liu ◽  
Yanchun Li ◽  
...  
Keyword(s):  
Fluorescence Intensity ◽  
Self Assembly ◽  
Triple Helix ◽  
Type I Collagen ◽  
Intrinsic Fluorescence ◽  
Type I ◽  
Food And Agriculture ◽  
Mechanism Research ◽  
Helix Structure ◽  
Assembly Behavior

The triple helix structure of collagen can be degraded by collagenase. In this study, we explored how the intrinsic fluorescence of type I collagen was influenced by collagenase I. We found that tyrosine was the main factor that could successfully excite the collagen fluorescence. Initially, self-assembly behavior of collagen resulted in a large amount of tyrosine wrapped with collagen, which decreased the fluorescence intensity of type I collagen. After collagenase cleavage, some wrapped-tyrosine could be exposed and thereby the intrinsic fluorescence intensity of collagen increased. By observation and analysis, the influence of collagenase to intrinsic fluorescence of collagen was investigated and elaborated. Furthermore, collagenase cleavage to the special triple helix structure of collagen would result in a slight improvement of collagen thermostability, which was explained by the increasing amount of terminal peptides. These results are helpful and effective for reaction mechanism research related to collagen, which can be observed by fluorescent technology. Meantime, the reaction behaviors of both collagenase and collagenolytic proteases can also be analyzed by fluorescent technology. In conclusion, this research provides a foundation for the further investigation of collagen reactions in different areas, such as medicine, nutrition, food and agriculture.

A study using quantum chemical theory methods on the intrinsic fluorescence emission and the possible emission mechanisms of PAMAM

RSC Advances ◽  
2014 ◽  
Vol 4 (102) ◽  
pp. 58788-58794 ◽  
Author(s):  
Yan Ji ◽  
Ying Qian
Keyword(s):  
Quantum Chemical ◽  
Fluorescence Emission ◽  
Pamam Dendrimers ◽  
Intrinsic Fluorescence ◽  
Structural Units ◽  
Chemical Theory

Structural units imidic acid (HO–CN) and tertiary ammonium in PAMAM dendrimers were proven to give fluorescence emission by TDDFT methods.

Inorganic Nanocrystals with Dendrimer Templates: Mesoscopic Model System and Route to New Nanocomposites

2001 ◽  
Vol 676 ◽  
Author(s):  
Franziska Gröhn ◽  
Barry J. Bauer ◽  
Eric J. Amis
Keyword(s):  
Aqueous Solution ◽  
Organic Solvent ◽  
Cadmium Sulfide ◽  
Pamam Dendrimers ◽  
Model System ◽  
Hybrid Structures ◽  
Host System ◽  
Hydrophobically Modified ◽  
Dendrimer Generation ◽  
Inorganic Nanocrystals

ABSTRACTWe investigate nanostructures that are formed when dendrimers act as hosts. Poly(amidoamine) (PAMAM) dendrimers can be used as templates for inorganic nanocrystals, both in aqueous solution1-3 and in a polymeric matrix4. SANS, SAXS and TEM are used to characterize the resulting hybrid structures. Different inorganic colloids like noble metal and cadmium sulfide colloids are studied1,2. With increasing dendrimer generation, we observe a transition from low molecular colloid stabilizing to an effective polymer templating in terms of a “host-guest nanoscale synthesis”. For these higher generation dendrimers, inorganic colloids are formed inside single dendrimer molecules and the size of the nanocrystal can precisely be controlled by the dendrimer generation (“fixed loading law”). Hydrophobically modified dendrimers in organic solvent represent a further, different kind of host system that we have investigated using scattering methods5.

Determination of non-traditional intrinsic fluorescence (NTIF) emission sites in 1-(4-carbomethoxypyrrolidone)-PAMAM dendrimers using CNDP-based quenching studies

2018 ◽  
Vol 20 (8) ◽  
Author(s):  
Malgorzata Konopka ◽  
Anna Janaszewska ◽  
Kayla A.M. Johnson ◽  
David Hedstrand ◽  
Donald A. Tomalia ◽  
...  
Keyword(s):  
Pamam Dendrimers ◽  
Intrinsic Fluorescence

The Intrinsic Fluorescence of Human Fibrinogen and Its Fragments D and E

1982 ◽  
Vol 48 (01) ◽  
pp. 021-023 ◽  
Author(s):  
M A Kowalska ◽  
C S Cierniewski
Keyword(s):  
Conformational Changes ◽  
Fluorescence Intensity ◽  
Degradation Products ◽  
Tryptophan Fluorescence ◽  
Intrinsic Fluorescence ◽  
Excitation Spectra ◽  
Ph Titration ◽  
Human Fibrinogen ◽  
Tryptophan Residues ◽  
Fibrinogen Molecule

SummaryThe tryptophan fluorescence of fibrinogen and its final degradation products - fragment D and E - were compared. Fibrinogen and its derivatives exhibit identical emission and excitation spectra. Their fluorescence intensity is influenced to a different extent by pH titration and temperature.Our studies showed that tryptophan residues of core fragments D and E are much more exposed to quenching effects of acrylamide and ions than intact fibrinogen, which may be caused by conformational changes occurring over the domains during plasmin digestion of fibrinogen molecule.

scholarly journals The Conformational Structural Change of Soy Glycinin via Lactic Acid Bacteria Fermentation Reduced Immunoglobulin E Reactivity

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2969
Author(s):  
Zhen Liu ◽  
Yaqiong Wang ◽  
Yifei Liu ◽  
Qiuqin Zhang ◽  
Wei Li ◽  
...  
Keyword(s):  
Particle Size ◽  
Conformational Changes ◽  
Fluorescence Intensity ◽  
Immunoglobulin E ◽  
Principal Component ◽  
Surface Hydrophobicity ◽  
Intrinsic Fluorescence ◽  
Enzyme Linked Immunosorbent Assay ◽  
Ige Reactivity ◽  
Α Helix

This study investigated the fermentation of isolated soy glycinin by using the Lactiplantibacillus plantarum B1-6 strain, its reduction effect on immunoglobulin E (IgE) reactivity, the relationship with protein aggregation/gelation state and conformational changes. Fermentation was performed under different glycinin concentrations (0.1%, 0.5%, 1% and 2%, w/v) and varied fermentation terminal pH levels (FT-pH) (pH 6.0, 4.5, 4.0 and 3.5). L. plantarum B1-6 showed potency in reducing immunoreactivity to 0.10–69.85%, as determined by a sandwich enzyme-linked immunosorbent assay. At a FT-pH of 6.0 and 4.5, extremely low IgE reactivity (0.1–22.32%) was observed. Fermentation resulted in a great increase (2.31–6.8-fold) in particle size and a loss of intensity in A3 and basic subunits. The conformation of glycinin was altered, as demonstrated by improved surface hydrophobicity (1.33–7.39-fold), decreased intrinsic fluorescence intensity and the α-helix structure. Among the four selected concentrations, glycinin at 1% (w/v, G-1) evolved the greatest particles during fermentation and demonstrated the lowest immunoreactivity. Principal component analysis confirmed that particle size, intrinsic fluorescence intensity, α-helix and ionic bond were closely related to immunoreactivity reduction.

pH dependent one-/two-photon fluorescence emission properties and mechanism of the dendrimer PAMAM triphenylamine imine

RSC Advances ◽  
2015 ◽  
Vol 5 (91) ◽  
pp. 74940-74946 ◽  
Author(s):  
Yan Ji ◽  
Ying Qian
Keyword(s):  
Fluorescence Emission ◽  
Pamam Dendrimers ◽  
Intrinsic Fluorescence ◽  
Emission Properties ◽  
Two Photon ◽  
Ph Dependent ◽  
Two Photon Fluorescence ◽  
Photon Fluorescence

pH dependent fluorescence emission of PTS-G0 and ETS were compared, to better understand intrinsic fluorescence phenomena of PAMAM dendrimers.

scholarly journals Intrinsic Fluorescence of PAMAM Dendrimers—Quenching Studies

Polymers ◽  
2018 ◽  
Vol 10 (5) ◽  
pp. 540 ◽  
Author(s):  
Malgorzata Konopka ◽  
Anna Janaszewska ◽  
Barbara Klajnert-Maculewicz
Keyword(s):  
Pamam Dendrimers ◽  
Intrinsic Fluorescence
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