Acute Cartilage Injury Induced by Trans-Articular Sutures

Objective To determine the extent of acute cartilage injury by using trans-articular sutures. Methods Five different absorbable sutures, monofilament polydioxanone (PDS) and braided polyglactin (Vicryl), were compared on viable human osteochondral explants. An atraumatic needle with 30 cm of thread was advanced through the cartilage with the final thread left in the tissue. A representative 300 μm transversal slice from the cartilage midportion was stained with Live/Dead probes, scanned under the confocal laser microscope, and analyzed for the diameters of (a) central “Black zone” without any cells, representing in situ thread thickness and (b) “Green zone,” including the closest Live cells, representing the maximum injury to the tissue. The exact diameters of suture needles and threads were separately measured under an optical microscope. Results The diameters of the Black (from 144 to 219 µm) and the Green zones (from 282 to 487 µm) varied between the different sutures ( P < 0.001). The Green/Black zone ratio remained relatively constant (from 1.9 to 2.2; P = 0.767). A positive correlation between thread diameters and PDS suturing material, toward the Black and Green zone, was established, but needle diameters did not reveal any influence on the zones. Conclusions The width of acute cartilage injury induced by the trans-articular sutures is about twice the thread thickness inside of the tissue. Less compressible monofilament PDS induced wider tissue injury in comparison to a softer braided Vicryl. Needle diameter did not correlate to the extent of acute cartilage injury.

Download Full-text

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.

Download Full-text

In-situ observation of graphene using an optical microscope

Applied Surface Science Advances ◽

10.1016/j.apsadv.2021.100138 ◽

2021 ◽

Vol 6 ◽

pp. 100138

Author(s):

Mikihiro Kato ◽

Sujun Guan ◽

Xinwei Zhao

Keyword(s):

Optical Microscope ◽

In Situ Observation

Download Full-text

Turn-on fluorescent probe for dopamine detection in solutions and live cells based on in situ formation of aminosilane-functionalized carbon dots

Analytica Chimica Acta ◽

10.1016/j.aca.2021.338394 ◽

2021 ◽

Vol 1157 ◽

pp. 338394

Author(s):

Xiao-Yue Tang ◽

Yi-Ming Liu ◽

Xiao-Lin Bai ◽

Hao Yuan ◽

Yi-Kao Hu ◽

...

Keyword(s):

Fluorescent Probe ◽

Carbon Dots ◽

Live Cells ◽

Turn On ◽

Dopamine Detection ◽

In Situ Formation

Download Full-text

A sample cell for the study of enzyme-induced carbonate precipitation at the grain-scale and its implications for biocementation

Scientific Reports ◽

10.1038/s41598-021-92235-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jennifer Zehner ◽

Anja Røyne ◽

Pawel Sikorski

Keyword(s):

Real Time ◽

Laser Scanning Microscopy ◽

In Situ Monitoring ◽

Confocal Laser ◽

Precipitation Process ◽

Successful Implementation ◽

Detailed Knowledge ◽

Carbonate Precipitation ◽

Sample Cell

AbstractBiocementation is commonly based on microbial-induced carbonate precipitation (MICP) or enzyme-induced carbonate precipitation (EICP), where biomineralization of $$\text {CaCO}_{3}$$ CaCO 3 in a granular medium is used to produce a sustainable, consolidated porous material. The successful implementation of biocementation in large-scale applications requires detailed knowledge about the micro-scale processes of $$\text {CaCO}_{3}$$ CaCO 3 precipitation and grain consolidation. For this purpose, we present a microscopy sample cell that enables real time and in situ observations of the precipitation of $$\text {CaCO}_{3}$$ CaCO 3 in the presence of sand grains and calcite seeds. In this study, the sample cell is used in combination with confocal laser scanning microscopy (CLSM) which allows the monitoring in situ of local pH during the reaction. The sample cell can be disassembled at the end of the experiment, so that the precipitated crystals can be characterized with Raman microspectroscopy and scanning electron microscopy (SEM) without disturbing the sample. The combination of the real time and in situ monitoring of the precipitation process with the possibility to characterize the precipitated crystals without further sample processing, offers a powerful tool for knowledge-based improvements of biocementation.

Download Full-text

A Study on the Effect of Alumina on the Morphology and Reduction Behavior of Sinter by In Situ Observation

Metals ◽

10.3390/met11050740 ◽

2021 ◽

Vol 11 (5) ◽

pp. 740

Author(s):

Sang Gyun Shin ◽

Wan Ho Kim ◽

Dong Joon Min

Keyword(s):

Reduction Rate ◽

Al2o3 Content ◽

Confocal Laser ◽

In Situ Observation ◽

Sintering Process ◽

Reduction Behavior ◽

Reducing Gas ◽

Interfacial Chemical Reaction ◽

Reaction Routes

The effects of Al2O3 content on the morphology and reducibility of sinter were respectively investigated using confocal laser microscopy and thermogravimetric analysis at 1273 K under CO gas. To understand the effects of the sintering process, separate samples were prepared via the equilibrium and metastable reaction routes. In the equilibrium samples, the addition of Al2O3 led to the formation of the silico-ferrite of calcium and alumino phase and a decrease in the reduction rate due to the lowered reactivity of iron oxide. In contrast, in the metastable samples, the reduction rate increased after the addition of 2.5 mass% Al2O3. The addition of Al2O3 decreased the fraction of the liquid phase and increased the fraction of pores in the sample. As a result, the reduction rate is proportional to the Al2O3 content owing to the changes in the sinter morphology. In determining the reduction rate of the sinter, the influence of the microstructure on the diffusion of the reducing gas is more significant than that of the interfacial chemical reaction due to the formation of the SFCA phase. The microstructure changes of the sinter with the addition of Al2O3 and the corresponding reduction behaviors are further discussed.

Download Full-text

In Situ Localization of Enzyme Activity in Live Cells by a Molecular Probe Releasing a Precipitating Fluorochrome

Angewandte Chemie ◽

10.1002/ange.201705747 ◽

2017 ◽

Vol 129 (39) ◽

pp. 11950-11954 ◽

Cited By ~ 27

Author(s):

Hong-Wen Liu ◽

Ke Li ◽

Xiao-Xiao Hu ◽

Longmin Zhu ◽

Qiming Rong ◽

...

Keyword(s):

Enzyme Activity ◽

Molecular Probe ◽

Live Cells

Download Full-text

Influence of Aging on Corrosion Behaviour of the 6061 Cast Aluminium Alloy

Materials ◽

10.3390/ma14081821 ◽

2021 ◽

Vol 14 (8) ◽

pp. 1821

Author(s):

Ting He ◽

Wei Shi ◽

Song Xiang ◽

Chaowen Huang ◽

Ronald G. Ballinger

Keyword(s):

Aluminium Alloy ◽

Laser Scanning ◽

Corrosion Behaviour ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Kelvin Probe ◽

Force Microscopy ◽

The Matrix ◽

6061 Aluminium Alloy

The influence of AlFeSi and Mg2Si phases on corrosion behaviour of the cast 6061 aluminium alloy was investigated. Scanning Kelvin probe force microscopy (SKPFM), electron probe microanalysis (EPMA), and in situ observations by confocal laser scanning microscopy (CLSM) were used. It was found that Mg2Si phases were anodic relative to the matrix and dissolved preferentially without significantly affecting corrosion propagation. The AlFeSi phases’ influence on 6061 aluminium alloy local corrosion was greater than that of the Mg2Si phases. The corroded region width reached five times that of the AlFeSi phase, and the accelerating effect was terminated as the AlFeSi dissolved.

Download Full-text

In Situ 3D-Imaging of the Inner Ear Synapses with a Cochlear Implant

Life ◽

10.3390/life11040301 ◽

2021 ◽

Vol 11 (4) ◽

pp. 301

Author(s):

Kathrin Malfeld ◽

Nina Armbrecht ◽

Holger A. Volk ◽

Thomas Lenarz ◽

Verena Scheper

Keyword(s):

Cochlear Implant ◽

Inner Ear ◽

Laser Scanning ◽

3D Imaging ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Sensory Cells ◽

Residual Hearing ◽

Preparation Methods

In recent years sensorineural hearing loss was found to affect not exclusively, nor at first, the sensory cells of the inner ear. The sensory cells’ synapses and subsequent neurites are initially damaged. Auditory synaptopathies also play an important role in cochlear implant (CI) care, as they can lead to a loss of physiological hearing in patients with residual hearing. These auditory synaptopathies and in general the cascades of hearing pathologies have been in the focus of research in recent years with the aim to develop more targeted and individually tailored therapeutics. In the current study, a method to examine implanted inner ears of guinea pigs was developed to examine the synapse level. For this purpose, the cochlea is made transparent and scanned with the implant in situ using confocal laser scanning microscopy. Three different preparation methods were compared to enable both an overview image of the cochlea for assessing the CI position and images of the synapses on the same specimen. The best results were achieved by dissection of the bony capsule of the cochlea.

Download Full-text