scholarly journals Quantitatively Monitoring in situ Mitochondrial Thermal Dynamics by Upconversion Nanoparticles

2020 ◽  
Author(s):  
Xiangjun Di ◽  
Dejiang Wang ◽  
Jiajia Zhou ◽  
Lin Zhang ◽  
Martina Stenzel ◽  
...  
Keyword(s):  
Living Cells ◽  
Upconversion Nanoparticles ◽  
Thermal Dynamics ◽  
Physiological Conditions ◽  
Temperature Responsive ◽  
Probe Concentration ◽  
Temperature Dynamics ◽  
Potential Applications ◽  
Sensing Sensitivity

AbstractTemperature dynamics reflect the physiological conditions of cells and organisms. Mitochondria regulates temperature dynamics in living cells, as they oxidize the respiratory substrates and synthesize ATP, with heat being released as a by-product of active metabolism. Here, we report an upconversion nanoparticles based thermometer that allows in situ thermal dynamics monitoring of mitochondria in living cells. We demonstrate that the upconversion nanothermometers can efficiently target mitochondria and the temperature responsive feature is independent of probe concentration and medium conditions. The relative sensing sensitivity of 3.2% K−1 in HeLa cells allows us to measure the mitochondrial temperature difference through the stimulations of high glucose, lipid, Ca2+ shock and the inhibitor of oxidative phosphorylation. Moreover, cells display distinct response time and thermal dynamic profiles under different stimulations, which highlights the potential applications of this thermometer to study in situ vital processes related to mitochondrial metabolism pathways and interactions between organelles.

scholarly journals Quantitatively Monitoring In Situ Mitochondrial Thermal Dynamics by Upconversion Nanoparticles

Nano Letters ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1651-1658
Author(s):  
Xiangjun Di ◽  
Dejiang Wang ◽  
Jiajia Zhou ◽  
Lin Zhang ◽  
Martina H. Stenzel ◽  
...  
Keyword(s):  
Upconversion Nanoparticles ◽  
Thermal Dynamics

An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

1988 ◽  
Vol 46 ◽  
pp. 884-885
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Defect Density ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Metal Base ◽  
In Situ Experiments ◽  
Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

scholarly journals Influence of protein (human galectin-3) design on aspects of lectin activity

2020 ◽  
Vol 154 (2) ◽  
pp. 135-153 ◽  
Author(s):  
Gabriel García Caballero ◽  
Donella Beckwith ◽  
Nadezhda V. Shilova ◽  
Adele Gabba ◽  
Tanja J. Kutzner ◽  
...  
Keyword(s):  
Protein Design ◽  
Full Range ◽  
Biological Information ◽  
The Novel ◽  
Modular Assembly ◽  
Binding Partners ◽  
Galectin 3 ◽  
Potential Applications ◽  
Similar Affinity

Abstract The concept of biomedical significance of the functional pairing between tissue lectins and their glycoconjugate counterreceptors has reached the mainstream of research on the flow of biological information. A major challenge now is to identify the principles of structure–activity relationships that underlie specificity of recognition and the ensuing post-binding processes. Toward this end, we focus on a distinct feature on the side of the lectin, i.e. its architecture to present the carbohydrate recognition domain (CRD). Working with a multifunctional human lectin, i.e. galectin-3, as model, its CRD is used in protein engineering to build variants with different modular assembly. Hereby, it becomes possible to compare activity features of the natural design, i.e. CRD attached to an N-terminal tail, with those of homo- and heterodimers and the tail-free protein. Thermodynamics of binding disaccharides proved full activity of all proteins at very similar affinity. The following glycan array testing revealed maintained preferential contact formation with N-acetyllactosamine oligomers and histo-blood group ABH epitopes irrespective of variant design. The study of carbohydrate-inhibitable binding of the test panel disclosed up to qualitative cell-type-dependent differences in sections of fixed murine epididymis and especially jejunum. By probing topological aspects of binding, the susceptibility to inhibition by a tetravalent glycocluster was markedly different for the wild-type vs the homodimeric variant proteins. The results teach the salient lesson that protein design matters: the type of CRD presentation can have a profound bearing on whether basically suited oligosaccharides, which for example tested positively in an array, will become binding partners in situ. When lectin-glycoconjugate aggregates (lattices) are formed, their structural organization will depend on this parameter. Further testing (ga)lectin variants will thus be instrumental (i) to define the full range of impact of altering protein assembly and (ii) to explain why certain types of design have been favored during the course of evolution, besides opening biomedical perspectives for potential applications of the novel galectin forms.

DNA nanolantern-based split aptamer probes for in-situ ATP imaging in living cells and lighting up mitochondria

The Analyst ◽  
2021 ◽  
Author(s):  
Yaxin Wang ◽  
Dong-Xia Wang ◽  
Jia-Yi Ma ◽  
Jing Wang ◽  
Yichen Du ◽  
...  
Keyword(s):  
Adenosine Triphosphate ◽  
Cell Metabolism ◽  
Living Cells ◽  
Expression Level ◽  
Specific Analysis

Accurate and specific analysis of adenosine triphosphate (ATP) expression level in living cells can provide valuable information for understanding cell metabolism, physiological activities and pathologic mechanism. Herein, DNA nanolantern-based split...

scholarly journals Variability and improvement of optical and antimicrobial performances for CQDs/mesoporous SiO2/Ag NPs composites via in situ synthesis

2021 ◽  
Vol 10 (1) ◽  
pp. 403-411
Author(s):  
Youliang Cheng ◽  
Mingjie Wang ◽  
Changqing Fang ◽  
Ying Wei ◽  
Jing Chen ◽  
...  
Keyword(s):  
Uv Light ◽  
Carbon Quantum Dots ◽  
Diffusion Method ◽  
Ag Nps ◽  
Uniform Size ◽  
High Antibacterial Activity ◽  
Fluorescent Materials ◽  
Potential Applications ◽  
Mesoporous Sio2

Abstract To change the optical properties and improve the antibacterial performances of carbon quantum dots (CQDs) and Ag NPs, mesoporous SiO2 spheres were combined with them to form the composites. In this paper, CQDs with a uniform size of about 3.74 nm were synthesized using glucose as carbon source. Then, CQDs/mesoporous SiO2/Ag NPs composites were obtained in situ under UV light irradiating by using mesoporous SiO2 and Ag NO3 as the carrier and silver resource, respectively. The diameter of CQDs/mesoporous SiO2/Ag NPs particles was in the range of 200–250 nm. With the increase in irradiating time, the red-shift in the UV-Vis spectrum for as-prepared CQDs/mesoporous SiO2/Ag NPs composites was found, and the adsorption peak was widened. In addition, the composites showed a high antibacterial activity against Staphylococcus aureus and Escherichia coli via disc diffusion method. These results indicated that inhibition circles for Ag NPs/mesoporous SiO2/CQDs and mesoporous SiO2/Ag NPs were similar in diameter. Furthermore, the two composites had a better bactericidal performance compared with other particles. Therefore, as-prepared CQDs/mesoporous SiO2/Ag NPs composites in this paper have great potential applications for fluorescent materials and antibacterial materials.

Drug Release Mechanism of Fast Temperature-Responsive Soy Protein/PNIPAAm IPN Hydrogels

2013 ◽  
Vol 781-784 ◽  
pp. 803-807 ◽  
Author(s):  
Yong Liu ◽  
Shou Lian Wei ◽  
Miao Chan Liao
Keyword(s):  
Soy Protein ◽  
Polymer Network ◽  
Reaction Medium ◽  
Interpenetrating Polymer Network ◽  
Release Mechanism ◽  
Porous Structures ◽  
Temperature Responsive ◽  
Drug Release Mechanism ◽  
Potential Applications ◽  
Fast Release

Fast temperature-responsive interpenetrating polymer network hydrogels based on soy protein and poly(N-isopropylacrylamide) (PNIPAAm) were prepared using the sodium bicarbonate (NaHCO3) solutions as the reaction medium. The structure and properties were characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The bovine serum albumin (BSA) release behaviors and release mechanism were also investigated. The results show that the proposed hydrogels have high porous structures and have a fast release rate. The BSA release mechanism belongs to an anomalous transport and the Fickian contribution is dominant. The proposed hydrogels may have the potential applications in the field of biomedical materials such as in the controlled release of drugs.

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