An overview of preconcentration techniques combined with inductively coupled plasma mass spectrometry for trace element determination in biological studies

In the last decades, the determination of trace elements in biological materials has emerged as an important area of study because of its relevance to human health and the environment. Inductively coupled plasma mass spectrometry (ICP-MS) has proven to be a powerful tool for trace element analysis, owing to its high sensitivity and ability to determine several elements in a single measurement. However, given the complex nature of biological matrices and the presence of elements, most of them at ultratrace levels, it becomes crucial to complement ICP-MS with preconcentration techniques to increase the sensitivity and selectivity of analytical methods. This article presents an exhaustive overview of liquid- and solid-phase preconcentration techniques used in combination with ICP-MS for trace element determination in different biological samples from 2000 to the present. An in-depth discussion of the advances on the application of state-of-the-art solvents and materials in trace element extraction and preconcentration is presented. Special attention is given to different strategies for elemental speciation analysis, employing both chromatographic and non-chromatographic techniques. The role of automation in these methodologies is also described. Finally, future trends and challenges related to this topic are discussed.

The influence of the weight-bearing state on three-dimensional (3D) planning in lower extremity realignment - analysis of novel vs. state-of-the-art planning approaches

BACKGROUND

The use of 3D planning to guide corrective osteotomies of the lower extremity is increasing in clinical practice. The use of computer-tomography (CT) data acquired in supine position neglects the weight-bearing (WB) state and the gold standard in 3D planning involves the manual adaption of the surgical plan after considering the WB state in long-leg radiographs (LLR). However, this process is subjective and dependent on the surgeons experience. A more standardized and automated method could reduce variability and decrease costs.

PURPOSE

The aim of the study was (1) to compare three different three-dimensional (3D) planning modalities for medial open-wedge high tibial osteotomy (MOWHTO) and (2) to describe the current practice of adapting NWB CT data after considering the WB state in LLR. The purpose of this study is to validate a new, standardized approach to include the WB state into the 3D planning and to compare this method against the current gold standard of 3D planning. Our hypothesis is that the correction is comparable to the gold standard, but shows less variability due compared to the more subjective hybrid approach.

METHODS

Three surgical planning modalities were retrospectively analyzed in 43 legs scheduled for MOWHTO between 2015 and 2019. The planning modalities included: (1) 3D hybrid (3D non-weight-bearing (NWB) CT models after manual adaption of the opening angle considering the WB state in LLR, (2) 3D NWB (3D NWB CT models) and (3) 3D WB (2D/3D registration of 3D NWB CT models onto LLR to simulate the WB state). The pre- and postoperative hip-knee-ankle angle (HKA) and the planned opening angle (°) were assessed and differences among modalities reported. The relationship between the reported differences and BMI, preoperative HKA (LLR), medial meniscus extrusion, Outerbridge osteoarthritis grade and joint line convergence angle (JLCA) was analyzed.

RESULTS

The mean (std) planned opening angle of 3D hybrid did not differ between 3D hybrid and 3D WB (0.4 ± 2.1°) (n.s.) but was higher in 3D hybrid compared to 3D NWB (1.1° ± 1.1°) (p = 0.039). 3D WB demonstrated increased preoperative varus deformity compared to 3D NWB: 6.7 ± 3.8° vs. 5.6 ± 2.7° (p = 0.029). Patients with an increased varus deformity in 3D WB compared to 3D NWB (> 2 °) demonstrated more extensive varus alignment in LLR (p = 0.009) and a higher JLCA (p = 0.013).

CONCLUSION

Small intermodal differences between the current practice of the reported 3D hybrid planning modality and a 3D WB approach using a 2D/3D registration algorithm were reported. In contrast, neglecting the WB state underestimates preoperative varus deformity and results in a smaller planned opening angle. This leads to potential under correction in MOWHTO, especially in patients with extensive varus deformities or JLCA.

CLINICAL RELEVANCE

Incorporating the WB state in 3D planning modalities has the potential to increase accuracy and lead to a more consistent and reliable planning in MOWHTO. The inclusion of the WB state in automatized surgical planning algorithms has the potential to reduce costs and time in the future.

Present results and methods of vectorcardiographic diagnostics of ischemic heart disease

This article presents an overview of existing approaches to perform vectorcardiographic (VCG) diagnostics of ischemic heart disease (IHD). Individual methodologies are divided into categories to create a comprehensive and clear overview of electrical cardiac activity measurement, signal pre-processing, features extraction and classification procedures. An emphasis is placed on methods describing the electrical heart space (EHS) by several features extraction techniques based on spatiotemporal characteristics or signal modelling and signal transformations. Performance of individual methodologies are compared depending on classification of extent of ischemia, acute forms - myocardial infarction (MI) and myocardial scars localization. Based on a comparison of imaging methods, the advantages of VCG over the standard 12-leads ECG such as providing a 3D orthogonal leads imaging, better performance, and appropriate computer processing are highlighted. The issues of electrical cardiac activity measurements on body surface, the lack of VKG databases supported by a more accurate imaging method, possibility of comparison with the physiology of individual cases are outlined as potential reserves for future research.

Natural language processing for automatic evaluation of free-text answers - a feasibility study based on the European Diploma in Radiology examination

BACKGROUND

Written medical examinations consist of multiple-choice questions and/or free-text answers. The latter require manual evaluation and rating, which is time-consuming and potentially error-prone. We tested whether natural language processing (NLP) can be used to automatically analyze free-text answers to support the review process.

METHODS

The European Board of Radiology of the European Society of Radiology provided representative datasets comprising sample questions, answer keys, participant answers, and reviewer markings from European Diploma in Radiology examinations. Three free-text questions with the highest number of corresponding answers were selected: Questions 1 and 2 were "unstructured" and required a typical free-text answer whereas question 3 was "structured" and offered a selection of predefined wordings/phrases for participants to use in their free-text answer. The NLP engine was designed using word lists, rule-based synonyms, and decision tree learning based on the answer keys and its performance tested against the gold standard of reviewer markings.

RESULTS

After implementing the NLP approach in Python, F1 scores were calculated as a measure of NLP performance: 0.26 (unstructured question 1, n = 96), 0.33 (unstructured question 2, n = 327), and 0.5 (more structured question, n = 111). The respective precision/recall values were 0.26/0.27, 0.4/0.32, and 0.62/0.55.

CONCLUSION

This study showed the successful design of an NLP-based approach for automatic evaluation of free-text answers in the EDiR examination. Thus, as a future field of application, NLP could work as a decision-support system for reviewers and support the design of examinations being adjusted to the requirements of an automated, NLP-based review process.

CLINICAL RELEVANCE STATEMENT

Natural language processing can be successfully used to automatically evaluate free-text answers, performing better with more structured question-answer formats. Furthermore, this study provides a baseline for further work applying, e.g., more elaborated NLP approaches/large language models.

KEY POINTS

• Free-text answers require manual evaluation, which is time-consuming and potentially error-prone. • We developed a simple NLP-based approach - requiring only minimal effort/modeling - to automatically analyze and mark free-text answers. • Our NLP engine has the potential to support the manual evaluation process. • NLP performance is better on a more structured question-answer format.

Implicit signatures of voluntary action reduce with repeated motor practice

The sense of controlling one's actions and their consequences is a critical aspect of successful motor activity. While motor performance typically improves with learning, it is unclear whether, how, and why higher order aspects of motor cognition are also affected. Here, we used an implicit measure of sense of agency-the 'intentional binding' effect-as participants learned to make a skilled action involving precise control of thumb adduction. These actions were predictably followed by a tone (the outcome). At pre-test, we showed the perceived time of the tone was shifted towards the thumb action, compared to a control condition in which tones occurred without actions. Next, a relevant training group learned to refine the direction of the thumb movement, while an irrelevant training group was trained on another movement. Manipulation checks demonstrated that, as expected, the relevant training group improved performance of the trained movement, while the irrelevant training group did not. Critically, while both groups still showed binding of the tone towards the thumb action at post-test, the relevant training group showed less binding than the irrelevant training group. Given the link between intentional binding and volitional control of action, we suggest our result demonstrates subjective agency over the outcome of a skilled action decreases as practice makes the skilled action more fluent. We suggest that this reduction in sense of agency over movement outcomes is consistent with the decreasing cognitive engagement, or automatization, that occurs during skill learning.

Optimization of 177Lu-labelling of DOTA-TOC, PSMA-I&T and FAPI-46 for clinical application

BACKGROUND

¹⁷⁷Lu-radiopharmaceuticals are routinely used for the treatment of various tumor entities. The productions of radiopharmaceuticals follow strict good-manufacturing practice guidelines and synthesis optimizations thereof have a strong impact on e.g. the quality of the product, radiation safety and costs. The purpose of this study is to optimize the precursor load of three radiopharmaceuticals. For that, different precursor loads were evaluated and compared to previously reported findings.

RESULTS

All three radiopharmaceuticals were successfully synthesized in high radiochemical purities and yields on the ML Eazy. The precursor load was optimized for [¹⁷⁷Lu]Lu-FAPI-46 from 27.0 to 9.7 µg/GBq, for [¹⁷⁷Lu]Lu-DOTATOC from 11 to 10 µg/GBq and for [¹⁷⁷Lu]Lu-PSMA-I&T from 16.3 to 11.6 µg/GBq.

CONCLUSIONS

We successfully reduced the precursor load for all three radiopharmaceuticals while maintaining their quality.

High-throughput analysis of the transcriptional patterns of sexual genes in malaria

BACKGROUND

Plasmodium falciparum (Pf) is the leading protozoan causing malaria, the most devastating parasitic disease. To ensure transmission, a small subset of Pf parasites differentiate into the sexual forms (gametocytes). Since the abundance of these essential parasitic forms is extremely low within the human host, little is currently known about the molecular regulation of their sexual differentiation, highlighting the need to develop tools to investigate Pf gene expression during this fundamental mechanism.

METHODS

We developed a high-throughput quantitative Reverse-Transcription PCR (RT-qPCR) platform to robustly monitor Pf transcriptional patterns, in particular, systematically profiling the transcriptional pattern of a large panel of gametocyte-related genes (GRG). Initially, we evaluated the technical performance of the systematic RT-qPCR platform to ensure it complies with the accepted quality standards for: (i) RNA extraction, (ii) cDNA synthesis and (iii) evaluation of gene expression through RT-qPCR. We then used this approach to monitor alterations in gene expression of a panel of GRG upon treatment with gametocytogenesis regulators.

RESULTS

We thoroughly elucidated GRG expression profiles under treatment with the antimalarial drug dihydroartemisinin (DHA) or the metabolite choline over the course of a Pf blood cycle (48 h). We demonstrate that both significantly alter the expression pattern of PfAP2-G, the gametocytogenesis master regulator. However, they also markedly modify the developmental rate of the parasites and thus might bias the mRNA expression. Additionally, we screened the effect of the metabolites lactate and kynurenic acid, abundant in severe malaria, as potential regulators of gametocytogenesis.

CONCLUSIONS

Our data demonstrate that the high-throughput RT-qPCR method enables studying the immediate transcriptional response initiating gametocytogenesis of the parasites from a very low volume of malaria-infected RBC samples. The obtained data expand the current knowledge of the initial alterations in mRNA profiles of GRG upon treatment with reported regulators. In addition, using this method emphasizes that asexual parasite stage composition is a crucial element that must be considered when interpreting changes in GRG expression by RT-qPCR, specifically when screening for novel compounds that could regulate Pf sexual differentiation.

Machine learning computational tools to assist the performance of systematic reviews: A mapping review

BACKGROUND

Within evidence-based practice (EBP), systematic reviews (SR) are considered the highest level of evidence in that they summarize the best available research and describe the progress in a determined field. Due its methodology, SR require significant time and resources to be performed; they also require repetitive steps that may introduce biases and human errors. Machine learning (ML) algorithms therefore present a promising alternative and a potential game changer to speed up and automate the SR process. This review aims to map the current availability of computational tools that use ML techniques to assist in the performance of SR, and to support authors in the selection of the right software for the performance of evidence synthesis.

METHODS

The mapping review was based on comprehensive searches in electronic databases and software repositories to obtain relevant literature and records, followed by screening for eligibility based on titles, abstracts, and full text by two reviewers. The data extraction consisted of listing and extracting the name and basic characteristics of the included tools, for example a tool's applicability to the various SR stages, pricing options, open-source availability, and type of software. These tools were classified and graphically represented to facilitate the description of our findings.

RESULTS

A total of 9653 studies and 585 records were obtained from the structured searches performed on selected bibliometric databases and software repositories respectively. After screening, a total of 119 descriptions from publications and records allowed us to identify 63 tools that assist the SR process using ML techniques.

CONCLUSIONS

This review provides a high-quality map of currently available ML software to assist the performance of SR. ML algorithms are arguably one of the best techniques at present for the automation of SR. The most promising tools were easily accessible and included a high number of user-friendly features permitting the automation of SR and other kinds of evidence synthesis reviews.

Systematic evaluation of isolation processes of microorganisms using spatial statistics

The evaluation of inoculation processes of microorganisms by robotic systems as well as by lab-technicians is compensable and can be missing consistency as human judgment will depend on the individual and may therefore be biased and less effective than models and algorithms evaluating spatial patterns. To address this problem, nearest neighbor analysis was used to investigate if it could be utilized as a method to evaluate isolation processes. The nearest neighbor analysis results in a comparable numeric value on the isolation process, which can be used to assess results of different inoculation processes. In this article, images of Petri dishes and simulated plates are used to investigate the effectiveness of nearest neighbor analysis, which is a method within spatial statistics. This analysis is applied to spatial data created by applying computer vision to localize the colonies on the plates. When evaluating plates made with the streaking technique method, it was found to be ineffective as the dense parts of the distribution resulted in the computer vision being unable to locate all of the colonies. Therefore, the nearest neighbor analysis is not suitable to evaluate streaking plates and other methods to evaluate such plates should be developed. However, when evaluating Petri dishes where the spread plating technique had been applied, it was found that nearest neighbor analysis can be a useful way to systematically evaluate isolation processes.

[Design, manufacture and evaluation of a multi-parameter controllable automatic fire-acupuncture instrument]

A multi-parameter controllable automatic fire-acupuncture instrument was developed by integrating traditional fire needling with modern medical device technology. A gun-like appearance was designed for easy hand-held operation, the electromagnetic induction was for heating needle body, a scale knob was for controlling the needle insertion depth, the combination of electromagnetic ejection and spring return was for the precise control of the needle retention time; and the changeable single ste-rile needle or multiple needles were adopted to meet individual demand, obtain high efficiency and prevent infection. All of these designs are associated with the overall process control system to ensure the exact controllability of needle body temperature, needling density, insertion depth and needle retention time. Besides, this device is advantageous at handy and aseptic operation with high efficiency, conformability and visualization. In this research, this instrument was tested in animals for the impacts of automatic fire needling on skin damage and fur growth. It is found that the accurate control of each parameter is of the significant advantage in the safety and effectiveness of treatment, which lays a solid foundation for the subsequent systematic review on safety and effectiveness.

Fine motor skill automatization and working memory in children with and without potential fine motor impairments: An explorative study

AIMS

The present study explored fine motor skill automatization and working memory in kindergarten children with and without potential fine motor impairments. For both groups, lower performance was expected in a cognitive-motor dual-task compared to single-tasks. Children with potential fine motor impairments were expected to show higher dual-task costs (indicating lower automatization) and lower working memory performance compared to children without potential fine motor impairments.

METHODS

The sample included 18 kindergarten children (mean age M = 67.17 months, SD = 4.34 months) with potential fine motor impairments (scoring at or below the 9th percentile of the manual dexterity scale of the Movement ABC-2; Petermann, 2011) and 36 children scoring above the 9th percentile of the manual dexterity scale of the Movement ABC-2 (mean age M = 67.56 months; SD = 3.74). All children completed a fine motor task (trail drawing) and a working memory task (digit span backwards) in single- and dual-task conditions.

RESULTS

Results showed an overall lower cognitive but not fine motor performance in the dual-task condition compared to the single-task condition. Overall, the group scoring above the 9th percentile showed a lower error-to-length ratio and higher working memory performance than the group with potential fine motor impairments. The dual-task costs did not differ between the groups.

CONCLUSIONS

Although the potential fine motor impaired children did not show an automatization deficit, they might be at risk of academic problems due to their lower fine motor and working memory performance. Implications for school and interventions are discussed.

Antimicrobial susceptibly testing determined by Alfred 60/AST (Alifax®) in a multi-sites' lab: performance's evaluation and optimisation of workflow

PURPOSE

New techniques are needed to speed-up the identification and antimicrobial susceptibility testing (AST) of bacteria associated with bloodstream infections. Alfred 60/AST (Alifax®, Polverara, Italy) performs AST by light scattering directly from positive blood cultures.

METHODS

We evaluated Alfred 60/AST performances for 4 months. Each new episode of bacteraemia was included and AST were compared to either our rapid automated AST (Vitek® 2) or disk diffusion method. The discrepancies were investigated using Etest®. The time-to-result (TTR) was evaluated by comparing the blood volume inserted into Alfred 60/AST, i.e. 2 versus 7 blood drops. Taking into account the TTR, the workflow of positive blood cultures and the availability of AST results was studied in order to optimize the implementation of Alfred 60/AST.

RESULTS

A total of 249 samples and 1108 antibiotics for AST were tested. After exclusion of unavailable results, 1008 antibiotics were analysed. 94.9% (n = 957/1008) of the antibiotics showed categorical agreement. There were 14 very major errors (VME), 24 major errors (ME) and 13 minor errors (mE). The VME were mostly related to clindamycin (64.3%) whereas meropenem and piperacillin-tazobactam constituted the major part (37.5% and 61.5%) of ME and mE respectively. Results were highly reliable for Enterobacterales and enterococci. The mean TTR ranged between 4.3 and 6.3 h and was statistically 20 min faster when applying the 7 blood drops protocol. We showed that Alfred 60/AST could give relievable results within working hours for positive blood culture which are flagged the same day between 12:00 am and 12:00 pm.

CONCLUSION

Our study confirmed that Alfred 60/AST gives reliable AST results in a short period of time, especially for Enterobacterales and enterococci. AST are thus obtained the same day of a positive blood culture. Clinical impact studies are mandatory to validate a 24/24 working.

Standardized high-throughput biomonitoring using DNA metabarcoding: Strategies for the adoption of automated liquid handlers

Reliable and comprehensive monitoring data are required to trace and counteract biodiversity loss. High-throughput metabarcoding using DNA extracted from community samples (bulk) or from water or sediment (environmental DNA) has revolutionized biomonitoring, given the capability to assess biodiversity across the tree of life rapidly with feasible effort and at a modest price. DNA metabarcoding can be upscaled to process hundreds of samples in parallel. However, while automated high-throughput analysis workflows are well-established in the medical sector, manual sample processing still predominates in biomonitoring laboratory workflows limiting the upscaling and standardization for routine monitoring applications. Here we present an automated, scalable, and reproducible metabarcoding workflow to extract DNA from bulk samples, perform PCR and library preparation on a liquid handler. Key features are the independent sample replication throughout the workflow and the use of many negative controls for quality assurance and quality control. We generated two datasets: i) a validation dataset consisting of 42 individual arthropod specimens of different species, and ii) a routine monitoring dataset consisting of 60 stream macroinvertebrate bulk samples. As a marker, we used the mitochondrial COI gene. Our results show that the developed single-deck workflow is free of laboratory-derived contamination and produces highly consistent results. Minor deviations between replicates are mostly due to stochastic differences for low abundant OTUs. Thus, we successfully demonstrated that robotic liquid handling can be used reliably from DNA extraction to final library preparation on a single deck, thereby substantially increasing throughput, reducing costs, and increasing data robustness for biodiversity assessments and monitoring.

Automated ex-situ detection of pitting corrosion and its effect on the mechanical integrity of rare earth magnesium alloy - WE43

This study develops a three-dimensional automated detection framework (PitScan) that systematically evaluates the severity and phenomenology of pitting corrosion. This framework uses a python-based algorithm to analyse microcomputer-tomography scans (μCT) of cylindrical specimens undergoing corrosion. The approach systematically identifies several surface-based corrosion features, enabling full spatial characterisation of pitting parameters, including pit density, pit size, pit depth as well as pitting factor according to ASTM G46-94. Furthermore, it is used to evaluate pitting formation in tensile specimens of a Rare Earth Magnesium alloy undergoing corrosion, and relationships between key pitting parameters and mechanical performance are established. Results demonstrated that several of the parameters described in ASTM G46-94, including pit number, pit density and pitting factor, showed little correlation to mechanical performance. However, this study did identify that other parameters showed strong correlations with the ultimate tensile strength and these tended to be directly linked to the reduction of the cross-sectional area of the specimen. Specifically, our results indicate, that parameters directly linked to the loss of the cross-sectional area (e.g. minimum material width), are parameters that are most suited to provide an indication of a specimen's mechanical performance. The automated detection framework developed in this study has the potential to provide a basis to standardise measurements of pitting corrosion across a range of metals and future prediction of mechanical strength over degradation time.

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In-vitro immersion study of dog bones manufactured from a WE43 Magnesium alloy.

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Novel approach characterizing spatial pit formation using micro-CT scans.

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Comparison of mass loss by hydrogen gas measurement and volume loss by μCT scans.

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Correlation between mechanical strength and geometrical pit formation features.

A neurocognitive model of flow states and the role of cerebellar internal models

This paper conceptualizes a comprehensive body of neurocognitive knowledge of flow states based on two primary competing neurocognitive theories underpinning flow's purported functioning, the transient hypofrontality hypothesis and the network synchronization model. With these models in mind, a new neurocognitive model of flow is synthesized based on the similarities of these pre-existing theories and utilizing the internal models of the cerebellum to elucidate the differences and crossover in the current flow research. Ultimately, this paper works to provide a platform for researchers to use as a future reference and for hypothesis generation.

Are small additions solved by direct retrieval from memory or automated counting procedures? A rejoinder to Chen and Campbell (2018)

Contrary to the longstanding and consensual hypothesis that adults mainly solve small single-digit additions by directly retrieving their answer from long-term memory, it has been recently argued that adults could solve small additions through fast automated counting procedures. In a recent article, Chen and Campbell (Psychonomic Bulletin & Review, 25, 739-753, 2018) reviewed the main empirical evidence on which this alternative hypothesis is based, and concluded that there is no reason to jettison the retrieval hypothesis. In the present paper, we pinpoint the fact that Chen and Campbell reached some of their conclusions by excluding some of the problems that need to be considered for a proper argumentation against the automated counting procedure theory. We also explain why, contrary to Chen and Campbell's assumption, the network interference model proposed by Campbell (Mathematical Cognition, 1, 121-164, 1995) cannot account for our data. Finally, we clarify a theoretical point of our model.

[Digitalization and use of artificial intelligence in microvascular reconstructive facial surgery]

BACKGROUND

When using digitalization and artificial intelligence (AI), large amounts of data (big data) are produced, which can be processed by computers and used in the field of microvascular-reconstructive craniomaxillofacial surgery (CMFS).

OBJECTIVE

The aim of this article is to summarize current applications of digitalized medicine and AI in microvascular reconstructive CMFS.

MATERIAL AND METHODS

Review of frequent applications of digital medicine for microvascular CMFS reconstruction, focusing on digital planning, navigation, robotics and potential applications with AI.

RESULTS

The broadest utilization of medical digitalization is in the virtual planning of microvascular transplants, individualized implants and template-guided reconstruction. Navigation is commonly used for ablative tumor surgery but less frequently in reconstructions. Robotics are mainly employed in the transoral approach for tumor surgery of the hypopharynx, whereas the use of AI is still limited even if possible applications would be automated virtual planning and monitoring systems.

CONCLUSION

The use of digitalized methods and AI are adjuncts to microvascular reconstruction. Automatization approaches and simplification of technologies will provide such applications to a broader clientele in the future; however, in CMFS, robotic-assisted resections and automated flap monitoring are not yet the standard of care.

Semi-automated Model to Accurately Counting Sympathetic Nervous Fibers

In recent years, the role of sympathetic nervous fibers in chronic inflammation has become increasingly evident. At the onset of inflammation, sympathetic activity is increased in the affected tissue. However, sympathetic fibers are largely absent from chronically inflamed tissues. Apparently, there is a very dynamic relationship between sympathetic innervation and the immune system in areas of inflammation, and hence a rapid and easy method for quantification of nerve fiber density of target organs is of great value to answer potential research questions. Sympathetic nerve ends lie in close proximity to immune cells in lymphoid tissues and lymphoid cells are equipped with catecholamine receptors. Catecholamines such as dopamine and adrenaline are secreted by sympathetic nervous fibers and can influence immune cell activity directly. Thereby the sympathetic nervous system immediately participates in the regulation of inflammation. Changes in innervation density could therefore indicate dysregulation of inflammatory processes. Currently, nervous fiber densities are either determined by tedious manual counting, which is not suitable for high throughput approaches, or by expensive automated processes relying on specialized software and high-end microscopy equipment. Usually, tyrosine hydroxylase (TH) is used as the marker for sympathetic fibers. In order to overcome the current quantification bottleneck with a cost-efficient alternative, an automated process was established and compared to the classic manual approach of counting TH-positive sympathetic fibers. Since TH is not exclusively expressed on sympathetic fibers, but also in a number of catecholamine-producing cells, a prerequisite for automated determination of fiber densities is to reliably distinguish between cells and fibers. Therefore, an additional stain using peripherin which is exclusively expressed in nervous fibers as a secondary marker was established. This new and simple method can be used as a high-throughput approach to reliably and quickly estimate sympathetic nervous system (SNS) nerve fiber density in target tissues.

Automatization and stress analysis data of CoCr laser weld fatigue tests

This work includes raw and analyzed test data when using a recently developed fatigue test method for miniature laser welds in cobalt-chromium (CoCr) alloy joints [1]: 10.1016/j.jmbbm.2019.07.004. The automization of fatigue tests is crucial for saving costs and personnel resources and that is the reason why the atomization threshold and the resulting spectrum data related to CoCr welds are provided here. The finite element method based stress computation output is provided related to shearing-mode tests to support the dataset as a whole. In addition, the compositional data of the parent material and the laser weld are given.

An affordable and automated imaging approach to acquire highly resolved individual data-an example of copepod growth in response to multiple stressors

Individual trait variation is essential for populations to cope with multiple stressors and continuously changing environments. The immense number of possible stressor combinations and the influence of phenotypic variation makes experimental testing for effects on organisms challenging. The acquisition of such data requires many replicates and is notoriously laborious. It is further complicated when responses occur over short time periods. To overcome such challenges, we developed an automated imaging platform to acquire temporally highly resolved individual data. We tested this platform by exposing copepods to a combination of a biotic stressor (predator cues) and a toxicant (copper) and measured the growth response of individual copepods. We tested the automatically acquired data against published manually acquired data with much lower temporal resolution. We find the same general potentiating effects of predator cues on the adverse effects of copper, and the influence of an individual’s clutch identity on its ability to resist stress, between the data obtained from low and high temporal resolution. However, when using the high temporal resolution, we also uncovered effects of clutch ID on the timing and duration of stage transitions, which highlights the importance of considering phenotypic variation in ecotoxicological testing. Phenotypic variation is usually not acknowledged in ecotoxicological testing. Our approach is scalable, affordable, and adjustable to accommodate both aquatic and terrestrial organisms, and a wide range of visually detectable endpoints. We discuss future extensions that would further widen its applicability.

On the efficiency of instruction-based rule encoding

Instructions have long been considered a highly efficient route to knowledge acquisition especially compared to trial-and-error learning. We aimed at substantiating this claim by identifying boundary conditions for such an efficiency gain, including the influence of active learning intention, repeated instructions, and working memory load and span. Our experimental design allowed us to not only assess how well the instructed stimulus-response (S-R) rules were implemented later on, but also to directly measure prior instruction encoding processes. This revealed that instruction encoding was boosted by an active learning intention which in turn entailed better subsequent rule implementation. As should be expected, instruction-based learning took fewer trials than trial-and-error learning to reach a similar performance level. But more importantly, even when performance was measured relative to the identical number of preceding correct implementation trials, this efficiency gain persisted both in accuracy and in speed. This suggests that the naturally greater number of failed attempts in the initial phase of trial-and-error learning also negatively impacted learning in subsequent trials due to the persistence of erroneous memory traces established beforehand. A single instruction trial was sufficient to establish the advantage over trial-and-error learning but repeated instructions were better. Strategic factors and inter-individual differences in WM span - the latter exclusively affecting trial-and-error learning presumably due to the considerably more demanding working memory operations - could reduce or even abolish this advantage, but only in error rates. The same was not true for response time gains suggesting generally more efficient task automatization in instruction-based learning.

High-Throughput Parallel Proteomic Sample Preparation Using 96-Well Polyvinylidene Fluoride (PVDF) Membranes and C18 Purification Plates

Meaningful proteomic-based biomarker discovery projects using primary human-derived specimens require the analysis of hundreds of samples in order to address the issue of interpersonal variability. Thus, robust high-throughput methods for the digestion of plasma samples are a prerequisite for such large clinical proteomic studies with hundreds of samples. Commonly used sample preparation methods are often difficult to parallelize and/or automate. Herein we describe a method for parallel 96-well plate-based sample preparation. Protein digestion is performed in 96-well polyvinylidene fluoride (PVDF) membrane plates and the subsequent purification in 96-well reversed phase C18 purification plates, enabling the usage of multichannel pipettes in all steps. The protocol can be applied using neat or depleted plasma/serum samples, but has also proven effective with other sample types.

Light-induced gene expression with photocaged IPTG for induction profiling in a high-throughput screening system

BACKGROUND

Inducible expression systems are frequently used for the production of heterologous proteins. Achieving maximum product concentrations requires induction profiling, namely the optimization of induction time and inducer concentration. However, the respective experiments can be very laborious and time-consuming. In this work, a new approach for induction profiling is presented where induction in a microtiter plate based cultivation system (BioLector) is achieved by light using photocaged isopropyl β-D-1-thiogalactopyranoside (cIPTG).

RESULTS

A flavin mononucleotide-based fluorescent reporter protein (FbFP) was expressed using a T7-RNA-polymerase dependent E. coli expression system which required IPTG as inducer. High power UV-A irradiation was directed into a microtiter plate by light-emitting diodes placed above each well of a 48-well plate. Upon UV irradiation, IPTG is released (uncaged) and induces product formation. IPTG uncaging, formation of the fluorescent reporter protein and biomass growth were monitored simultaneously in up to four 48-well microtiter plates in parallel with an in-house constructed BioLector screening system. The amount of released IPTG can be gradually and individually controlled for each well by duration of UV-A exposure, irradiance and concentration of photocaged IPTG added at the start of the cultivation. A comparison of experiments with either optical or conventional IPTG induction shows that product formation and growth are equivalent. Detailed induction profiles revealed that for the strain and conditions used maximum product formation is reached for very early induction times and with just 6-8 s of UV-A irradiation or 60-80 µM IPTG.

CONCLUSIONS

Optical induction and online monitoring were successfully combined in a high-throughput screening system and the effect of optical induction with photocaged IPTG was shown to be equivalent to conventional induction with IPTG. In contrast to conventional induction, optical induction is less costly to parallelize, easy to automate, non-invasive and without risk of contamination. Therefore, light-induced gene expression with photocaged IPTG is a highly advantageous method for the efficient optimization of heterologous protein production and has the potential to replace conventional induction with IPTG.

Investigation of basic cognitive predictors of reading and spelling abilities in Tunisian third-grade primary school children

BACKGROUND

This study investigated first the main cognitive abilities; phonological processing, visual cognition, automatization and receptive vocabulary in predicting reading and spelling abilities in Arabic. Second, we compared good/poor readers and spellers to detect the characteristics of cognitive predictors which contribute to identifying reading and spelling difficulties in Arabic speaking children.

METHODS

A sample of 116 Tunisian third-grade children was tested on their abilities to read and spell, phonological processing, visual cognition, automatization and receptive vocabulary.

RESULTS

For reading, phonological processing and automatization uniquely predicted Arabic word reading and paragraph reading abilities. Automatization uniquely predicted Arabic non-word reading ability. For spelling, phonological processing was a unique predictor for Arabic word spelling ability. Furthermore, poor readers had significantly lower scores on the phonological processing test and slower reading times on the automatization test as compared with good readers. Additionally, poor spellers showed lower scores on the phonological processing test as compared with good spellers. Visual cognitive processing and receptive vocabulary were not significant cognitive predictors of Arabic reading and spelling abilities for Tunisian third grade children in this study.

CONCLUSIONS

Our results are consistent with previous studies in alphabetic orthographies and demonstrate that phonological processing and automatization are the best cognitive predictors in detecting early literacy problems. We suggest including phonological processing and automatization tasks in screening tests and in intervention programs may help Tunisian children with poor literacy skills overcome reading and spelling difficulties in Arabic.

Perseveration causes automatization of checking behavior in obsessive-compulsive disorder

Repeated checking leads to reductions in meta-memory (i.e., memory confidence, vividness and detail), and automatization of checking behavior (Dek, van den Hout, Giele, & Engelhard, 2014, 2015). Dek et al. (2014) suggested that this is caused by increased familiarity with the checked stimuli. They predicted that defamiliarization of checking by modifying the perceptual characteristics of stimuli would cause de-automatization and attenuate the negative meta-memory effects of re-checking. However, their results were inconclusive. The present study investigated whether repeated checking leads to automatization of checking behavior, and if defamiliarization indeed leads to de-automatization and attenuation of meta-memory effects in patients with OCD and healthy controls. Participants performed a checking task, in which they activated, deactivated and checked threat-irrelevant stimuli. During a pre- and post-test checking trial, check duration was recorded and a reaction time task was simultaneously administered as dual-task to assess automatization. After the pre- and post-test checking trial, meta-memory was rated. Results showed that relevant checking led to automatization of checking behavior on the RT measure, and negative meta-memory effects for patients and controls. Defamiliarization led to de-automatization measured with the RT task, but did not attenuate the negative meta-memory effects of repeated checking. Clinical implications are discussed.

Automated CBED processing: sample thickness estimation based on analysis of zone-axis CBED pattern

An automated processing of convergent beam electron diffraction (CBED) patterns is presented. The proposed methods are used in an automated tool for estimating the thickness of transmission electron microscopy (TEM) samples by matching an experimental zone-axis CBED pattern with a series of patterns simulated for known thicknesses. The proposed tool detects CBED disks, localizes a pattern in detected disks and unifies the coordinate system of the experimental pattern with the simulated one. The experimental pattern is then compared disk-by-disk with a series of simulated patterns each corresponding to different known thicknesses. The thickness of the most similar simulated pattern is then taken as the thickness estimate. The tool was tested on [0 1 1] Si, [0 1 0] α-Ti and [0 1 1] α-Ti samples prepared using different techniques. Results of the presented approach were compared with thickness estimates based on analysis of CBED patterns in two beam conditions. The mean difference between these two methods was 4.1% for the FIB-prepared silicon samples, 5.2% for the electro-chemically polished titanium and 7.9% for Ar(+) ion-polished titanium. The proposed techniques can also be employed in other established CBED analyses. Apart from the thickness estimation, it can potentially be used to quantify lattice deformation, structure factors, symmetry, defects or extinction distance.

Miniaturized planar chromatography using office peripherals--office chromatography

Office chromatography (OC) harnesses the novel combination of miniaturized planar separation science and modern print & media technologies. Interdisciplinary knowledge is the essence: Printing of solutions on powerful miniaturized planar separation materials in combination with image capturing and evaluation tools enables an innovative analytical online system. Site-specific printing as lines or areas on defined sections of the layer comprises important steps like application of samples, feeding of the mobile phase as well as supply of the derivatization reagent. Also printing of bioassays can be combined for effect-directed detections and the homogeneous printing of the ultrathin layer itself, enabling tailor-made gradient-layer or multi-layer plates. OC exploits image-giving miniaturized chromatograms being captured and processed with a flatbed scanner or mini-camera. Thus, miniaturized separation materials are the core of OC. Monolithic, electrospun, nanostructured glancing angle deposition and carbon nanotube-templated microfabricated layers or even pillar arrays or polymer brush coated sub-μm silica particles were demonstrated, showing promising results. Layer thicknesses from 50 μm down to few micrometers were explored. A high-throughput capacity is given through the parallel development of as many as possible tiny-printed samples on the separation material. The migration time was reduced to a few minutes and the calculated analysis time per sample lasted few seconds. Considering a substantially reduced solvent consumption at short run times for parallel analysis of numerous samples at the same time, OC is an appropriate analytical technique for green chemistry. OC facilitates the whole planar separation process to be performed with no other equipment but a combined device of printer and flatbed scanner or mini-camera. At the same time, OC can be expected to become a widespread and economical technique with the user-friendliness of high-end office tools, appealing to users.

Impaired automatization of a cognitive skill in first-degree relatives of patients with schizophrenia

We studied healthy, first-degree relatives of patients with schizophrenia to test the hypothesis that deficits in cognitive skill learning are associated with genetic liability to schizophrenia. Using the Weather Prediction Task (WPT), 23 healthy controls and 10 adult first-degree Relatives Of Schizophrenia (ROS) patients were examined to determine the extent to which cognitive skill learning was automated using a dual-task paradigm to detect subtle impairments in skill learning. Automatization of a skill is the ability to execute a task without the demand for executive control and effortful behavior and is a skill in which schizophrenia patients possess a deficit. ROS patients did not differ from healthy controls in accuracy or reaction time on the WPT either during early or late training on the single-task trials. In contrast, the healthy control and ROS groups were differentially affected during the dual-task trials. Our results demonstrate that the ROS group did not automate the task as well as controls and continued to rely on controlled processing even after extensive practice. This suggests that adult ROS patients may engage in compensatory strategies to achieve normal levels of performance and support the hypothesis that impaired cognitive skill learning is associated with genetic risk for schizophrenia.