scholarly journals Multiple Zones Modification of Open Off-Stoichiometry Thiol-Ene Microchannel by Aptamers: A Methodological Study & A Proof of Concept

Chemosensors ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 24
Author(s):  
Samantha Bourg ◽  
Fanny d’Orlyé ◽  
Sophie Griveau ◽  
Fethi Bedioui ◽  
Jose Alberto Fracassi da Silva ◽  
...  

Off-stoichiometry thiol-ene polymer (OSTE) is an emerging thermoset with interesting properties for the development of lab-on-a-chip (LOAC), such as easy microfabrication process, suitable surface chemistry for modification and UV-transparency. One of the challenges for LOAC development is the integration of all the analytical steps in one microchannel, and particularly, trace level analytes extraction/preconcentration steps. In this study, two strategies for the immobilization of efficient tools for this purpose, thiol-modified (C3-SH) aptamers, on OSTE polymer surfaces were developed and compared. The first approach relies on a direct UV-initiated click chemistry reaction to graft thiol-terminated aptamers on ene-terminated OSTE surfaces. The second strategy consists of the immobilization of thiol-terminated aptamers onto OSTE substrates covered by gold nanoparticles. The presence of an intermediate gold nanoparticle layer on OSTE has shown great interest in the efficient immobilization of aptamers, preserving their interaction with the target, and preventing non-specific adsorption. With this second innovative strategy, we proved, for the first time the concept of creating multiple functional zones for sample treatment in an open OSTE-microchannel thanks to the immobilization of aptamers in consecutive areas by the simple droplet deposition methodology. This methodological development allows further consideration of OSTE material for lab-on-a-chip designs, integrating multiple zones for sample pretreatment, based on molecular recognition by ligands, such as aptamers, in a specific zone of the microchannel and is adaptable to a large range of analytical applications for LOAC industrialization.

2021 ◽  
pp. 8-20

Micellar therapy has become a usefully viable treatment arm in various fields, ranging from oncology to bioimaging. As such, research leading to any improvements or adaptations in administration and techniques can have far-reaching consequences. Potential aspects of prebiotic chemistry may also be explored in such research as well. To that end, proof-of-concept experiments were performed to elucidate a possible mechanism of action for prebiotic protocell division. Representative potentially prebiotically plausible biomolecules, i.e., a fatty acid, amino acid, and nucleotide were mixed and heated in water and subjected to microscopic examination for observation of possible self-division and laboratory testing for the presence of polypeptides and polynucleotides (Biuret, MALDI mass-spec, etc.) with and without the presence of nucleotide. The results are presented for the first time here and a mechanism is proposed that best fits the data obtained. The evolutionary, e.g., prebiotic biomolecular cooperativity, and clinical, e.g., potential antineoplastic micellar/vesicular therapy, ramifications are discussed as well. Keywords: Micelle; Liposome; Protocell; MRNA; Self-division; Mechanism; Solid tumors


Radiocarbon ◽  
1981 ◽  
Vol 23 (3) ◽  
pp. 410-421 ◽  
Author(s):  
Dušan Srdoč ◽  
Adela Sliepčevic ◽  
Bogomil Obelic ◽  
Nada Horvatinčic

The following radiocarbon date list contains dates of samples measured since our previous list (R, 1979, v 21, p 131-137). As before, age calculations are based on the Libby half-life 5570 ± 30 yr and reported in years before 1950. The modern standard is 0.95 of the activity of NBS oxalic acid. Sample pretreatment, combustion, and counting technique are essentially the same as described in R, 1971, v 13, p 135-140, supplemented by new techniques for groundwater processing (R, 1979, v 21, p 131-137) and for soil sample treatment (R, 1977, v 19, p 465-475).


2019 ◽  
Vol 47 (14) ◽  
pp. e82-e82
Author(s):  
Choong Yong Ung ◽  
Mehrab Ghanat Bari ◽  
Cheng Zhang ◽  
Jingjing Liang ◽  
Cristina Correia ◽  
...  

Abstract With the emergence of genome editing technologies and synthetic biology, it is now possible to engineer genetic circuits driving a cell's phenotypic response to a stressor. However, capturing a continuous response, rather than simply a binary ‘on’ or ‘off’ response, remains a bioengineering challenge. No tools currently exist to identify gene candidates responsible for predetermining and fine-tuning cell response phenotypes. To address this gap, we devised a novel Regulostat Inferelator (RSI) algorithm to decipher intrinsic molecular devices or networks that predetermine cellular phenotypic responses. The RSI algorithm is designed to extract gene expression patterns from basal transcriptomic data in order to identify ‘regulostat’ constituent gene pairs, which exhibit rheostat-like mode-of-cooperation capable of fine-tuning cellular response. Our proof-of-concept study provides computational evidence for the existence of regulostats and that these networks predetermine cellular response prior to exposure to a stressor or drug. In addition, our work, for the first time, provides evidence of context-specific, drug–regulostat interactions in predetermining drug response phenotypes in cancer cells. Given RSI-inferred regulostat networks offer insights for prioritizing gene candidates capable of rendering a resistant phenotype sensitive to a given drug, we envision that this tool will be of great value in bioengineering and medicine.


2013 ◽  
Vol 9 ◽  
pp. 1170-1178 ◽  
Author(s):  
Aleksey I Gerasyuto ◽  
Zhi-Xiong Ma ◽  
Grant S Buchanan ◽  
Richard P Hsung

A successful enone version of an intramolecular aza-[3 + 3] annulation reaction is described here. Use of piperidinium trifluoroacetate salt as the catalyst and toluene as the solvent appears to be critical for a successful annulation. We also demonstrated for the first time that microwave irradiation can accelerate aza-[3 + 3] annulation reactions. An attempt to expand the scope of the enone aza-[3 + 3] annulation was made in the form of propyleine synthesis as a proof of concept. While synthesis of the enone annulation precursor was successfully accomplished, the annulation proved to be challenging and was only modestly successful.


2018 ◽  
Vol 54 (36) ◽  
pp. 4589-4592 ◽  
Author(s):  
Thomas P. Nicholls ◽  
Johnathon C. Robertson ◽  
Michael G. Gardiner ◽  
Alex C. Bissember

The results of a proof-of-concept study demonstrate for the first time that pulsed LED irradiation enhances the rate of product formation and the yield of a visible light-mediated photoredox-catalysed reaction.


2019 ◽  
Vol 875 ◽  
Author(s):  
Jianqing Huang ◽  
Hecong Liu ◽  
Weiwei Cai

Online in situ prediction of 3-D flame evolution has been long desired and is considered to be the Holy Grail for the combustion community. Recent advances in computational power have facilitated the development of computational fluid dynamics (CFD), which can be used to predict flame behaviours. However, the most advanced CFD techniques are still incapable of realizing online in situ prediction of practical flames due to the enormous computational costs involved. In this work, we aim to combine the state-of-the-art experimental technique (that is, time-resolved volumetric tomography) with deep learning algorithms for rapid prediction of 3-D flame evolution. Proof-of-concept experiments conducted suggest that the evolution of both a laminar diffusion flame and a typical non-premixed turbulent swirl-stabilized flame can be predicted faithfully in a time scale on the order of milliseconds, which can be further reduced by simply using a few more GPUs. We believe this is the first time that online in situ prediction of 3-D flame evolution has become feasible, and we expect this method to be extremely useful, as for most application scenarios the online in situ prediction of even the large-scale flame features are already useful for an effective flame control.


2014 ◽  
Vol 05 (01) ◽  
pp. 264-283 ◽  
Author(s):  
F. Köpcke ◽  
T. Leusch ◽  
R.W. Majeed ◽  
B. Schreiweis ◽  
J. Wenk ◽  
...  

SummaryObjective: (1) To define features and data items of a Patient Recruitment System (PRS); (2) to design a generic software architecture of such a system covering the requirements; (3) to identify implementation options available within different Hospital Information System (HIS) environments; (4) to implement five PRS following the architecture and utilizing the implementation options as proof of concept.Methods: Existing PRS were reviewed and interviews with users and developers conducted. All reported PRS features were collected and prioritized according to their published success and user’s request. Common feature sets were combined into software modules of a generic software architecture. Data items to process and transfer were identified for each of the modules. Each site collected implementation options available within their respective HIS environment for each module, provided a prototypical implementation based on available implementation possibilities and supported the patient recruitment of a clinical trial as a proof of concept.Results: 24 commonly reported and requested features of a PRS were identified, 13 of them prioritized as being mandatory. A UML version 2 based software architecture containing 5 software modules covering these features was developed. 13 data item groups processed by the modules, thus required to be available electronically, have been identified. Several implementation options could be identified for each module, most of them being available at multiple sites. Utilizing available tools, a PRS could be implemented in each of the five participating German university hospitals.Conclusion: A set of required features and data items of a PRS has been described for the first time. The software architecture covers all features in a clear, well-defined way. The variety of implementation options and the prototypes show that it is possible to implement the given architecture in different HIS environments, thus enabling more sites to successfully support patient recruitment in clinical trials.Citation: Trinczek B, Köpcke F, Leusch T, Majeed RW, Schreiweis B, Wenk J, Bergh B, Ohmann C, Röhrig R, Prokosch HU, Dugas M. Design and multicentric implementation of a generic software architecture for patient recruitment systems re-using existing HIS tools and routine patient data. Appl Clin Inf 2014; 5: 264–283 http://dx.doi.org/10.4338/ACI-2013-07-RA-0047


2021 ◽  
Author(s):  
Bernhard Seidl ◽  
Rainer Schuhmacher ◽  
Christoph Bueschl

The use of stable isotopically labeled tracers is a long-proven way of specifically detecting and tracking derived metabolites through a metabolic network of interest. While recently developed stable isotope assisted methods and associated, supporting data analysis tools have greatly improved untargeted metabolomics approaches, no software tool is currently available that allows to automatically search LC-HRMS chromatograms for completely free user-definable isotopolog patterns expected for the metabolism of labeled tracer substances. Here we present Custom Pattern Extract (CPExtract), a versatile software tool that allows for the first time the high-throughput search for user-defined isotopolog patterns in LC-HRMS data. The patterns can be specified via a set of rules including the presence or absence of certain isotopologs, their relative intensity ratios as well as chromatographic co-elution. Each isotopolog pattern satisfying the respective rules is verified on a MS-scan level and also in the chromatographic domain. The CPExtract algorithm allows the use of both labeled tracer compounds in non-labeled biological samples as well as a reversed tracer approach, employing non-labeled tracer compounds along with globally labeled biological samples. In a proof of concept study we searched for metabolites specifically arising from the malonate pathway of the filamentous fungi Fusarium graminearum and Trichoderma reesei. 1,2,3- 13 C 3 -malonic acid diethyl ester and native malonic acid monomethyl ester were used as tracers. We were able to reliably detect expected fatty acids and known polyketides. In addition, up to 189 and 270 further, unknown metabolites presumably including novel polyketides were detected in the F. graminearum and T. reesei culture samples respectively, all of which exhibited the user-predicted isotopolog patterns originating from the malonate tracer incorporation. The software can be used for every conceivable tracer approach. Furthermore, the rule sets can be easily adapted or extended if necessary. CPExtract is available free of charge for non-commercial use at https://metabolomics-ifa.boku.ac.at/CPExtract.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Simon Hazubski ◽  
Harald Hoppe ◽  
Andreas Otte

Abstract In the field of neuroprosthetics, the current state-of-the-art method involves controlling the prosthesis with electromyography (EMG) or electrooculography/electroencephalography (EOG/EEG). However, these systems are both expensive and time consuming to calibrate, susceptible to interference, and require a lengthy learning phase by the patient. Therefore, it is an open challenge to design more robust systems that are suitable for everyday use and meet the needs of patients. In this paper, we present a new concept of complete visual control for a prosthesis, an exoskeleton or another end effector using augmented reality (AR) glasses presented for the first time in a proof-of-concept study. By using AR glasses equipped with a monocular camera, a marker attached to the prosthesis is tracked. Minimal relative movements of the head with respect to the prosthesis are registered by tracking and used for control. Two possible control mechanisms including visual feedback are presented and implemented for both a motorized hand orthosis and a motorized hand prosthesis. Since the grasping process is mainly controlled by vision, the proposed approach appears to be natural and intuitive.


Sign in / Sign up

Export Citation Format

Share Document