| 1. |
- Golczak, Sebastian, et al.
(författare)
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Comparative XPS surface study of polyaniline thin films
- 2008
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Ingår i: Solid State Ionics. - : Elsevier BV. - 0167-2738 .- 1872-7689. ; 179:39, s. 2234-2239
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Tidskriftsartikel (refereegranskat)abstract
- Polyaniline (PANI) films of different thickness have been deposited electrochemically at two different potentials of 0.8 and 1.2 V. Characterization of the surface composition of the material: oxidation states and structural changes have been performed using X-ray photoelectron spectroscopy (XPS). The main findings of this work show that the ratio of the imine to amine nitrogens for thicker films of PANI is close to unity, indicating that the surface layer of PANI is in the emeraldine form (base). On the other hand, the surface of thinner films of PANI contains similar to 14-20% imine nitrogen and similar to 60-70% amine nitrogen. This corresponds to an oxidation state close to that of protoemeraldine. Furthermore, XPS confirms a considerable amount of p-benzoquinone (BQ) as side product formed in all thin samples. The surface morphology examined by electron microscopy measurements shows that thin films have a uniform structure, whereas microporous structure with microchannels and microcaves inside, formed as a non-periodic network of microrods is characteristic for thicker PANI films.
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| 2. |
- Michalska, Agnieszka, et al.
(författare)
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Micro- and Nanostructured Polyaniline for Instant Identification of Metal Ions in Solution
- 2019
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Ingår i: Nanomaterials. - : MDPI AG. - 2079-4991. ; 9:2
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Tidskriftsartikel (refereegranskat)abstract
- The unique properties of nanomaterials enable the creation new analytical devices. Polyaniline (PANI) micro- and nanofiber network, freestanding in the gap between two gold microelectrodes, has been used in a new nanodetector for metal ions in solutions. The gold electrodes were modified with the aid of alkanethiols, forming a self-assembled monolayer (SAM), which is able to block the ion current flow, but also to interact with metal ions when specific functional molecules are incorporated into the layer. The electric field of the trapped metal ions induces change of the electrical conductivity of polyaniline nanofibers in vicinity. A small injected sample (75 mu L) of a solution of salt (about 0.5 mu g of salt) was enough to induce a reproducible change in the electrical conductivity of polyaniline nano-network, which was registered as a function of time within 10-20 s. The response was proportional to the concentration of ions. It also depends on properties of ions, e.g., the ionic radius, which allows for identification of metal ions by analyzing the parameters of the signal: the retention time (RT), half width (HW), amplitude (A) and integral intensity (INT). The advantage of the new device is the instant responsiveness and easy operation, but also the simple construction based on organic (polymer) technology. The system is "open"-when learned and calibrated adequately, other metal ions can be analyzed. The nanodetector can be used in cases where monitoring of the presence and concentration of metal ions is important.
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| 3. |
- Langer, Krzysztof, et al.
(författare)
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A conversational robotic lab assistant for automated microfluidic 3d microtissue production
- 2019
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Ingår i: 23rd International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2019. - : Chemical and Biological Microsystems Society. ; , s. 888-889
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Konferensbidrag (refereegranskat)abstract
- The future of life science is linked to automation and microfluidics. Here we present a robotic lab assistant, a general automation platform for droplet microfluidics including a conversational mobile interface. We demonstrate the automated production of human cancer microtissues in droplets at a throughput of 85000 spheroids per microfluidic circuit per hour. The capability of automated spheroid generation is directly applicable to precision medicine and drug screening. Multiple cell lines were successfully tested, including cancer cell lines, co-cultures, and primary cells. The 3D-microtissues/spheroids were automatically assembled-incubated-retrieved with high viability for further drug screening analysis - the platform interfaces with standard labware.
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| 4. |
- Langer, Krzysztof, et al.
(författare)
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Rapid production and recovery of cell spheroids by automated droplet microfluidics
- 2019
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Droplet microfluidics enables high throughput cell processing, analysis and screening by miniaturizing the reaction vessels to nano- or pico-liter water-in oil droplets, but like many other microfluidic formats, droplet microfluidics have not been interfaced with or automated by laboratory robotics. Here we demonstrate automation of droplet microfluidics based on an inexpensive liquid handling robot for the automated production of human scaffold-free cell spheroids, using pipette actuation and interfacing the pipetting tip with a droplet generating microfluidic chip. In this chip we produce highly mono-disperse 290μm droplets with diameter CV of 1.7%. By encapsulating cells in these droplets, we produce cell spheroids in droplets and recover them to standard formats at a throughput of 85000 spheroids per microfluidic circuit per hour. The viability of the cells in spheroids remains high after recovery only decreased by 4% starting from 96% after 16 hours incubation in nanoliter droplets. Scaffold-free cell spheroids and 3D tissue constructs recapitulate many aspects of functional human tissue more accurately than 2D or single cell cultures, but assembly methods for spheroids, e.g. hanging drop micro-plates, has had limited throughput. The increased throughput and decreased cost of our method enables spheroid production at the scale needed for lead discovery drug screening and approaches the cost where these micro tissues could be used as building blocks for organ scale regenerative medicine.
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| 5. |
- Langer, Krzysztof, et al.
(författare)
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Rapid Production and Recovery of Cell Spheroids by Automated Droplet Microfluidics
- 2020
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Ingår i: SLAS TECHNOLOGY. - : Elsevier BV. - 2472-6303 .- 2472-6311. ; 25:2, s. 111-122
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Tidskriftsartikel (refereegranskat)abstract
- The future of the life sciences is linked to automation and microfluidics. As robots start working side by side with scientists, robotic automation of microfluidics in general, and droplet microfluidics in particular, will significantly extend and accelerate the life sciences. Here, we demonstrate the automation of droplet microfluidics using an inexpensive liquid-handling robot to produce human scaffold-free cell spheroids at high throughput. We use pipette actuation and interface the pipetting tip with a droplet-generating microfluidic device. In this device, we produce highly monodisperse droplets with a diameter coefficient of variation (CV) lower than 2%. By encapsulating cells in these droplets, we produce cell spheroids in droplets and recover them to standard labware containers at a throughput of 85,000 spheroids per microfluidic circuit per hour. The viability of the cells in spheroids remains high throughout the process and decreases by >10% (depending on the cell line used) after a 16 h incubation period in nanoliter droplets and automated recovery. Scaffold-free cell spheroids and 3D tissue constructs recapitulate many aspects of functional human tissue more accurately than 2D or single-cell cultures, but assembly methods for spheroids (e.g., hanging drop microplates) have limited throughput. The increased throughput and decreased cost of our method enable spheroid production at the scale needed for lead discovery drug screening, and approach the cost at which these microtissues could be used as building blocks for organ-scale regenerative medicine.
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| 6. |
- Trossbach, Martin, et al.
(författare)
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High-throughput cell spheroid production and assembly analysis by microfluidics and deep learning
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- 3D cell culture models are an important tool in translational research but have been out of reach for high-throughput screening due to complexity, requirement of large cell numbers and inadequate standardization. Here, we present a high-throughput workflow to produce and characterize the formation of miniaturized spheroids using deep learning. We train a convolutional neural network (CNN) for cell ensemble morphology classification, benchmark it against more conventional image analysis, and characterize spheroid assembly determining optimal surfactant concentrations and incubation times for spheroid production for three cell lines with different spheroid formation properties. Notably, this format is compatible with large-scale spheroid production and screening. The presented workflow and CNN offer a template for large scale minispheroid production and analysis and can be extended and re-trained to characterize morphological responses in spheroids to additives, culture conditions and large drug libraries.
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| 7. |
- Trossbach, Martin, et al.
(författare)
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High-throughput cell spheroid production and assembly analysis by microfluidics and deep learning
- 2023
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Ingår i: SLAS TECHNOLOGY. - : Elsevier BV. - 2472-6303 .- 2472-6311. ; 28:6, s. 423-432
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Tidskriftsartikel (refereegranskat)abstract
- 3D cell culture models are important tools in translational research but have been out of reach for high-throughput screening due to complexity, requirement of large cell numbers and inadequate standardization. Microfluidics and culture model miniaturization technologies could overcome these challenges. Here, we present a high throughput workflow to produce and characterize the formation of miniaturized spheroids using deep learning. We train a convolutional neural network (CNN) for cell ensemble morphology classification for droplet microfluidic minispheroid production, benchmark it against more conventional image analysis, and characterize minispheroid assembly determining optimal surfactant concentrations and incubation times for minispheroid production for three cell lines with different spheroid formation properties. Notably, this format is compatible with large-scale spheroid production and screening. The presented workflow and CNN offer a template for large scale minispheroid production and analysis and can be extended and re-trained to characterize morphological responses in spheroids to additives, culture conditions and large drug libraries.
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| 8. |
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| 9. |
- Zamora, Juan Carlos, et al.
(författare)
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Considerations and consequences of allowing DNA sequence data as types of fungal taxa
- 2018
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Ingår i: IMA Fungus. - : INT MYCOLOGICAL ASSOC. - 2210-6340 .- 2210-6359. ; 9:1, s. 167-185
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Tidskriftsartikel (refereegranskat)abstract
- Nomenclatural type definitions are one of the most important concepts in biological nomenclature. Being physical objects that can be re-studied by other researchers, types permanently link taxonomy (an artificial agreement to classify biological diversity) with nomenclature (an artificial agreement to name biological diversity). Two proposals to amend the International Code of Nomenclature for algae, fungi, and plants (ICN), allowing DNA sequences alone (of any region and extent) to serve as types of taxon names for voucherless fungi (mainly putative taxa from environmental DNA sequences), have been submitted to be voted on at the 11th International Mycological Congress (Puerto Rico, July 2018). We consider various genetic processes affecting the distribution of alleles among taxa and find that alleles may not consistently and uniquely represent the species within which they are contained. Should the proposals be accepted, the meaning of nomenclatural types would change in a fundamental way from physical objects as sources of data to the data themselves. Such changes are conducive to irreproducible science, the potential typification on artefactual data, and massive creation of names with low information content, ultimately causing nomenclatural instability and unnecessary work for future researchers that would stall future explorations of fungal diversity. We conclude that the acceptance of DNA sequences alone as types of names of taxa, under the terms used in the current proposals, is unnecessary and would not solve the problem of naming putative taxa known only from DNA sequences in a scientifically defensible way. As an alternative, we highlight the use of formulas for naming putative taxa (candidate taxa) that do not require any modification of the ICN.
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