Digital colloid-enhanced Raman spectroscopy by single-molecule counting.

Quantitative detection of various molecules at very low concentrations in complex mixtures has been the main objective in many fields of science and engineering, from the detection of cancer-causing mutagens and early disease markers to environmental pollutants and bioterror agents1-5. Moreover, technologies that can detect these analytes without external labels or modifications are extremely valuable and often preferred6. In this regard, surface-enhanced Raman spectroscopy can detect molecular species in complex mixtures on the basis only of their intrinsic and unique vibrational signatures7. However, the development of surface-enhanced Raman spectroscopy for this purpose has been challenging so far because of uncontrollable signal heterogeneity and poor reproducibility at low analyte concentrations8. Here, as a proof of concept, we show that, using digital (nano)colloid-enhanced Raman spectroscopy, reproducible quantification of a broad range of target molecules at very low concentrations can be routinely achieved with single-molecule counting, limited only by the Poisson noise of the measurement process. As metallic colloidal nanoparticles that enhance these vibrational signatures, including hydroxylamine-reduced-silver colloids, can be fabricated at large scale under routine conditions, we anticipate that digital (nano)colloid-enhanced Raman spectroscopy will become the technology of choice for the reliable and ultrasensitive detection of various analytes, including those of great importance for human health.

Exploring the link between a novel approach for computer aided lung sound analysis and imaging biomarkers: a cross-sectional study.

BACKGROUND: Computer Aided Lung Sound Analysis (CALSA) aims to overcome limitations associated with standard lung auscultation by removing the subjective component and allowing quantification of sound characteristics. In this proof-of-concept study, a novel automated approach was evaluated in real patient data by comparing lung sound characteristics to structural and functional imaging biomarkers. METHODS: Patients with cystic fibrosis (CF) aged > 5y were recruited in a prospective cross-sectional study. CT scans were analyzed by the CF-CT scoring method and Functional Respiratory Imaging (FRI). A digital stethoscope was used to record lung sounds at six chest locations. Following sound characteristics were determined: expiration-to-inspiration (E/I) signal power ratios within different frequency ranges, number of crackles per respiratory phase and wheeze parameters. Linear mixed-effects models were computed to relate CALSA parameters to imaging biomarkers on a lobar level. RESULTS: 222 recordings from 25 CF patients were included. Significant associations were found between E/I ratios and structural abnormalities, of which the ratio between 200 and 400 Hz appeared to be most clinically relevant due to its relation with bronchiectasis, mucus plugging, bronchial wall thickening and air trapping on CT. The number of crackles was also associated with multiple structural abnormalities as well as regional airway resistance determined by FRI. Wheeze parameters were not considered in the statistical analysis, since wheezing was detected in only one recording. CONCLUSIONS: The present study is the first to investigate associations between auscultatory findings and imaging biomarkers, which are considered the gold standard to evaluate the respiratory system. Despite the exploratory nature of this study, the results showed various meaningful associations that highlight the potential value of automated CALSA as a novel non-invasive outcome measure in future research and clinical practice.

Artificial intelligence and medical education: application in classroom instruction and student assessment using a pharmacology & therapeutics case study.

BACKGROUND: Artificial intelligence (AI) tools are designed to create or generate content from their trained parameters using an online conversational interface. AI has opened new avenues in redefining the role boundaries of teachers and learners and has the potential to impact the teaching-learning process. METHODS: In this descriptive proof-of- concept cross-sectional study we have explored the application of three generative AI tools on drug treatment of hypertension theme to generate: (1) specific learning outcomes (SLOs); (2) test items (MCQs- A type and case cluster; SAQs; OSPE); (3) test standard-setting parameters for medical students. RESULTS: Analysis of AI-generated output showed profound homology but divergence in quality and responsiveness to refining search queries. The SLOs identified key domains of antihypertensive pharmacology and therapeutics relevant to stages of the medical program, stated with appropriate action verbs as per Bloom's taxonomy. Test items often had clinical vignettes aligned with the key domain stated in search queries. Some test items related to A-type MCQs had construction defects, multiple correct answers, and dubious appropriateness to the learner's stage. ChatGPT generated explanations for test items, this enhancing usefulness to support self-study by learners. Integrated case-cluster items had focused clinical case description vignettes, integration across disciplines, and targeted higher levels of competencies. The response of AI tools on standard-setting varied. Individual questions for each SAQ clinical scenario were mostly open-ended. The AI-generated OSPE test items were appropriate for the learner's stage and identified relevant pharmacotherapeutic issues. The model answers supplied for both SAQs and OSPEs can aid course instructors in planning classroom lessons, identifying suitable instructional methods, establishing rubrics for grading, and for learners as a study guide. Key lessons learnt for improving AI-generated test item quality are outlined. CONCLUSIONS: AI tools are useful adjuncts to plan instructional methods, identify themes for test blueprinting, generate test items, and guide test standard-setting appropriate to learners' stage in the medical program. However, experts need to review the content validity of AI-generated output. We expect AIs to influence the medical education landscape to empower learners, and to align competencies with curriculum implementation. AI literacy is an essential competency for health professionals.

Validation of 2D flow MRI for helical and vortical flows.

PURPOSE: The main objective of this study was to develop two-dimensional (2D) phase contrast (PC) methods to quantify the helicity and vorticity of blood flow in the aortic root. METHODS: This proof-of-concept study used four-dimensional (4D) flow cardiovascular MR (4D flow CMR) data of five healthy controls, five patients with heart failure with preserved ejection fraction and five patients with aortic stenosis (AS). A PC through-plane generated by 4D flow data was treated as a 2D PC plane and compared with the original 4D flow. Visual assessment of flow vectors was used to assess helicity and vorticity. We quantified flow displacement (FD), systolic flow reversal ratio (sFRR) and rotational angle (RA) using 2D PC. RESULTS: For visual vortex flow presence near the inner curvature of the ascending aortic root on 4D flow CMR, sFRR demonstrated an area under the curve (AUC) of 0.955, p<0.001. A threshold of >8% for sFRR had a sensitivity of 82% and specificity of 100% for visual vortex presence. In addition, the average late systolic FD, a marker of flow eccentricity, also demonstrated an AUC of 0.909, p<0.001 for visual vortex flow. Manual systolic rotational flow angle change (ΔsRA) demonstrated excellent association with semiautomated ΔsRA (r=0.99, 95% CI 0.9907 to 0.999, p<0.001). In reproducibility testing, average systolic FD (FDsavg) showed a minimal bias at 1.28% with a high intraclass correlation coefficient (ICC=0.92). Similarly, sFRR had a minimal bias of 1.14% with an ICC of 0.96. ΔsRA demonstrated an acceptable bias of 5.72°-and an ICC of 0.99. CONCLUSION: 2D PC flow imaging can possibly quantify blood flow helicity (ΔRA) and vorticity (FRR). These imaging biomarkers of flow helicity and vorticity demonstrate high reproducibility for clinical adoption. TRIALS REGISTRATION NUMBER: NCT05114785.

Multicentre, randomised, double-blind, placebo-controlled, proof of concept study of LSALT peptide as prevention of acute respiratory distress syndrome and acute kidney injury in patients infected with SARS-CoV-2 (COVID-19).

OBJECTIVE: Dipeptidase-1 (DPEP-1) is a recently discovered leucocyte adhesion receptor for neutrophils and monocytes in the lungs and kidneys and serves as a potential therapeutic target to attenuate inflammation in moderate-to-severe COVID-19. We aimed to evaluate the safety and efficacy of the DPEP-1 inhibitor, LSALT peptide, to prevent specific organ dysfunction in patients hospitalised with COVID-19. DESIGN: Phase 2a randomised, placebo-controlled, double-blinded, trial. SETTING: Hospitals in Canada, Turkey and the USA. PARTICIPANTS: A total of 61 subjects with moderate-to-severe COVID-19. INTERVENTIONS: Randomisation to LSALT peptide 5 mg intravenously daily or placebo for up to 14 days. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary endpoint was the proportion of subjects alive and free of respiratory failure and/or the need for renal replacement therapy (RRT). Numerous secondary and exploratory endpoints were assessed including ventilation-free days, and changes in kidney function or serum biomarkers. RESULTS: At 28 days, 27 (90.3%) and 28 (93.3%) of subjects in the placebo and LSALT groups were free of respiratory failure and the need for RRT (p=0.86). On days 14 and 28, the number of patients still requiring more intensive respiratory support (O2 ≥6 L/minute, non-invasive or invasive mechanical ventilation or extracorporeal membrane oxygenation) was 6 (19.4%) and 3 (9.7%) in the placebo group versus 2 (6.7%) and 2 (6.7%) in the LSALT group, respectively (p=0.14; p=0.67). Unadjusted analysis of ventilation-free days demonstrated 22.8 days for the LSALT group compared with 20.9 in the placebo group (p=0.4). LSALT-treated subjects had a significant reduction in the fold expression from baseline to end of treatment of serum CXCL10 compared with placebo (p=0.02). Treatment-emergent adverse events were similar between groups. CONCLUSION: In a Phase 2 study, LSALT peptide was demonstrated to be safe and tolerated in patients hospitalised with moderate-to-severe COVID-19. TRIAL REGISTRATION NUMBER: NCT04402957.

A proof-of-concept study evaluating cardiac compression techniques for cardiopulmonary resuscitation in laying hens (Gallus gallus).

OBJECTIVE: To determine in adult chickens which of 3 CPR techniques, sternal compressions (SC), SC with interposed caudal coelomic compressions (ICCC), or lateral compressions (LC), results in the highest mean systolic (SAP), diastolic (DAP), and mean arterial pressure (MAP) as measured directly from the carotid artery. DESIGN: Prospective, nonblinded, experimental crossover study. SETTING: University teaching hospital laboratory. ANIMALS: Ten retired laying hens. INTERVENTIONS: Birds were sedated, anesthetized, and placed in dorsal recumbency. A carotid artery catheter was placed to directly measure arterial pressure. Ventricular fibrillation was induced with direct cardiac stimulation using a 9-Volt battery. Each bird then received 2 minutes of the 3 different cardiac compression techniques in a random order by 3 different compressors, with the compressor order also randomized. Birds were subsequently administered IV epinephrine, and transthoracic defibrillation was attempted. At the end of experimentation, each bird was euthanized, and simple gross necropsies were performed. Linear mixed models followed by pairwise paired t-tests were performed to evaluate differences in pressures generated by each technique. MEASUREMENTS AND MAIN RESULTS: The primary study outcomes were SAP, DAP, and MAP over 2 minutes of compressions for each compression technique. Pressures from ICCC (SAP: 27.6 ± 5.3 mm Hg, DAP: 18.7 ± 5.2 mm Hg, MAP: 21.7 ± 5.2 mm Hg) were significantly higher than those from LC (SAP: 18.9 ± 5.4 mm Hg, DAP: 11.6 ± 4.1 mm Hg, MAP: 14.1 ± 4.5 mm Hg). Pressures from SC (SAP: 24.5 ± 6.4 mm Hg, DAP: 15.2 ± 4.3 mm Hg, MAP: 18.3 ± 5.0 mm Hg) were not significantly different from ICCC or LC. CONCLUSIONS: External compressions can generate detectable increases in arterial pressure in chickens with ventricular fibrillation. SC with ICCC generated significantly higher arterial pressures than LC. SC alone generated blood pressures that were not significantly different from those generated by SC with ICCC or LC.

GARD™skin and GARD™potency: A proof-of-concept study investigating applicability domain for agrochemical formulations.

Several New Approach Methodologies (NAMs) for hazard assessment of skin sensitisers have been formally validated. However, data regarding their applicability on certain product classes are limited. The purpose of this project was to provide initial evidence on the applicability domain of GARD™skin and GARD™potency for the product class of agrochemical formulations. For this proof of concept, 30 liquid and 12 solid agrochemical formulations were tested in GARDskin for hazard predictions. Formulations predicted as sensitisers were further evaluated in the GARDpotency assay to determine GHS skin sensitisation category. The selected formulations were of product types, efficacy groups and sensitisation hazard classes representative of the industry's products. The performance of GARDskin was estimated by comparing results to existing in vivo animal data. The overall accuracy, sensitivity, and specificity were 76.2% (32/42), 85.0% (17/20), and 68.2% (15/22), respectively, with the predictivity for liquid formulations being slightly higher compared to the solid formulations. GARDpotency correctly subcategorized 14 out of the 17 correctly predicted sensitisers. Lack of concordance was justifiable by compositional or borderline response analysis. In conclusion, GARDskin and GARDpotency showed satisfactory performance in this initial proof-of-concept study, which supports consideration of agrochemical formulations being within the applicability domain of the test methods.

An exploratory view into allelic drop-out of sequenced autosomal STRs.

As massively parallel sequencing is implemented in forensic genetics, an understanding of sequence data must accompany these advancements, that is, accurate modeling of data for proper statistical analysis. Allelic drop-out, a common stochastic effect seen in genetic data, is often modeled in statistical analysis of STR results. This proof-of-concept study sequenced several serial dilutions of a standard sample ranging from 4 ng to 7.82 pg to evaluate allelic drop-out trends on a select panel of autosomal STRs using the ForenSeq™ DNA Signature Prep Kit, Primer Set A on the Illumina MiSeq FGx. Parameters assessed included locus, profile, and run specific information. A majority of the allelic drop-out occurred in DNA concentrations less than 31.25 pg. Statistical results indicated a need for locus-specific modeling based on STR descriptors, like simple versus compound repeat patterns. No correlation was seen between average read count of scored alleles and allelic drop-out at a locus. A statistical correlation was observed between the amount of allelic drop-out and the starting amount of DNA in a sample, average read count of a sample, and total read count generated on a flow cell. This study supports using common allelic drop-out factors used in fragment length analysis on sequenced STRs while including additional locus, sample, and run specific information. Results demonstrate multiple factors that can be considered when developing probability of allelic drop-out models for sequenced autosomal STRs including locus-specific analysis, total read count of a profile, and total read count sequenced on a flow cell.

Short-term reduction of dietary gluten improves metabolic-dysfunction associated steatotic liver disease: A randomised, controlled proof-of-concept study.

BACKGROUND: The current management of metabolic dysfunction-associated steatotic liver disease (MASLD) relies on lifestyle intervention. Prior studies have shown that nutritional wheat amylase trypsin inhibitors (ATI) activate toll-like receptor 4 on intestinal myeloid cells to enhance intestinal and extra-intestinal inflammation, including the promotion of murine MASLD, insulin resistance and liver fibrosis. AIMS: We aimed to assess the impact of ATI (gluten)-free diet in liver as well as metabolic parameters of biopsy-proven MASLD patients. METHODS: We performed a 6-week, proof-of-concept 1:1 randomised controlled trial of an ATI-free diet. The controls followed a balanced diet recommended by the German Nutrition Society. We assessed changes in controlled attenuation parameter (CAP), body mass index (BMI) and homeostatic model assessment of insulin resistance (HOMA-IR). Patient-reported outcomes were assessed by the CLDQ-NASH questionnaire. Forty-five patients were consecutively enrolled (21 in the intervention arm and 24 in the control arm). RESULTS: Three patients from each arm discontinued the study. In the ATI-free diet group, a significant decrease in BMI (p = 0.018), CAP (p = 0.018) and HOMA-IR (p = 0.042) was observed at 6 weeks. The mean difference in CAP between the two arms at week 6 was 30.5 dB/m (p = 0.039), with a delta significantly higher in the ATI-free diet group (p = 0.043). Only an ATI-free diet could achieve a significant improvement in CLDQ-NASH domains (p value for total scoring: 0.013). CONCLUSIONS: A short-term ATI-free diet leads to significant improvements in liver and metabolic parameters, as well as patient-reported outcomes with good tolerability. A larger follow-up study is justified to corroborate these findings. CLINICAL TRIAL NUMBER: NCT04066400.

Ketogenic Diet Intervention on Metabolic and Psychiatric Health in Bipolar and Schizophrenia: A Pilot Trial.

The ketogenic diet (KD, also known as metabolic therapy) has been successful in the treatment of obesity, type 2 diabetes, and epilepsy. More recently, this treatment has shown promise in the treatment of psychiatric illness. We conducted a 4-month pilot study to investigate the effects of a KD on individuals with schizophrenia or bipolar disorder with existing metabolic abnormalities. Twenty-three participants were enrolled in a single-arm trial. Results showcased improvements in metabolic health, with no participants meeting metabolic syndrome criteria by study conclusion. Adherent individuals experienced significant reduction in weight (12 %), BMI (12 %), waist circumference (13 %), and visceral adipose tissue (36 %). Observed biomarker enhancements in this population include a 27 % decrease in HOMA-IR, and a 25 % drop in triglyceride levels. In psychiatric measurements, participants with schizophrenia showed a 32 % reduction in Brief Psychiatric Rating Scale scores. Overall Clinical Global Impression (CGI) severity improved by an average of 31 %, and the proportion of participants that started with elevated symptomatology improved at least 1-point on CGI (79 %). Psychiatric outcomes across the cohort encompassed increased life satisfaction (17 %) and enhanced sleep quality (19 %). This pilot trial underscores the potential advantages of adjunctive ketogenic dietary treatment in individuals grappling with serious mental illness.

The Mediator Role of Illness Representations in Patients with Obstructive Sleep Apnea: A Preliminary Study / [El papel mediador de las representaciones de la enfermedad en pacientes de apnea obstructiva del sueño: un estudio preliminar]

Background: This preliminary study examined the mediating role of illness representations on health-related quality of life (HRQoL) between adherent and poorly adherent obstructive sleep apnea patients (OSA) to the automatic positive airway pressure (APAP) therapy. Method: A total of 185 patients were assessed on determinants of APAP treatment, illness representations, family coping, and self-efficacy, at T1 (prior to APAP treatment) and T2 (1 to 2 months with APAP treatment). Results: Regarding the determinants of APAP, adherent patients showed higher self-efficacy, outcome expectations, and decisional balance index, compared to poorly adherent patients. Adherent patients also showed higher family coping and HRQoL, but less threatening cognitive representations compared to poorly adherent patients. Illness cognitive and emotional representations mediated the relationship between self-efficacy/family coping and HRQoL, in adherent patients. Only illness cognitive representations mediated the relationship between self-efficacy and HRQoL in poorly adherent patients. Conclusions: The results highlight the importance of illness representations during OSA treatment in the promotion of adherence to APAP.(AU)

Antecedentes: Este estudio preliminar examina el papel mediador de la representación de la enfermedad en la calidad de vida relacionada con la salud (CVRS) entre pacientes con apnea obstructiva del sueño (AOS) observantes y poco observantes de la terapia de presión positiva automática en las vías respiratorias (APAP). Método: Se evaluó a un total de 185 pacientes sobre los determinantes del tratamiento APAP, las representaciones de la enfermedad, el afrontamiento familiar y la autoeficacia en T1 (antes del tratamiento APAP) y T2 (1 a 2 meses con tratamiento APAP). Resultados: En cuanto a los determinantes de la APAP, los observantes mostraron mayor autoeficacia, expectativas de resultados e índice de equilibrio decisional en comparación con los poco observantes. Los observantes también mostraron un mayor afrontamiento familiar y CVRS pero menos representaciones cognitivas amenazantes en comparación con los observantes deficientes. Las representaciones cognitivas y emocionales de la enfermedad mediaron la relación entre la autoeficacia/afrontamiento familiar y la CVRS en pacientes observantes. Solo las representaciones cognitivas de enfermedad mediaron la relación entre la autoeficacia y la CVRS en pacientes de baja observancia. Conclusiones: Los resultados destacan la importancia de las representaciones de la enfermedad durante el tratamiento de la AOS en la promoción de la adherencia a la APAP.(AU)

Activation of endodontic irrigants using a 9.3 µm CO2 and diode lasers: A laboratory proof of concept model.

PURPOSE: To investigate the differences between irrigant propagation and temperature changes using laser-activated irrigation (LAI) at different settings in an artificial root canal model. METHODS: Using an artificial resin root canal model, irrigant activation was achieved in 19 experimental groups with eight samples each. A 9,300 nm CO2 laser, two diode lasers with different settings (wavelengths 455, 808, 970, and 980 nm) were compared to 2,940 nm Er:YAG laser and traditional needle irrigation. Er:YAG and CO2 laser were activated in the pulpal chamber only, while diode lasers and needles were inserted into the main root canal. Lasers were activated for 5x 20 seconds resulting in 100 seconds of activation or rinsing for each sample. After each activation of 20 seconds, a photo was taken of the side canals and the propagation of the dye was measured with a digital measuring tool after calibration. Further, the temperature of the irrigant was reported after activation of 20 seconds and repeated 5 times. Data were checked for normality and statistically compared. RESULTS: All lasers increased the irrigant propagation compared to conventional irrigation. Significant differences were found between groups regarding propagation and temperature (P< 0.0027). Er:YAG and CO2 laser had similar effects on irrigant propagation in middle and apical located side-canals with specific power parameters and were superior to diode lasers and syringe irrigation. The irrigant's temperature increased significantly with the diode and CO2 lasers. CLINICAL SIGNIFICANCE: Diode lasers and CO2 lasers have not been established for irrigant activation. 9,300 nm CO2 lasers absorb well in water and were shown to introduce vapor bubble formation and streaming in water. Diode lasers are highly accepted in periodontics. The laser light is not absorbed in water but interacts with bacteria as well as soft tissues and contributes therefore to infection control. With a modified laser tip it was however possible to introduce cavitation and streaming in irrigants.

Efficacy and safety of crisaborole ointment, 2%, in participants aged ≥45 years with stasis dermatitis: Results from a fully decentralized, randomized, proof-of-concept phase 2a study.

BACKGROUND: Crisaborole ointment, 2%, is a nonsteroidal topical phosphodiesterase 4 inhibitor approved for the treatment of mild-to-moderate atopic dermatitis. OBJECTIVE: To evaluate the efficacy and safety of crisaborole in stasis dermatitis (SD). METHODS: In this randomized, double-blind, vehicle-controlled, decentralized phase 2a study (NCT04091087), 65 participants aged ≥45 years with SD without active ulceration received crisaborole or vehicle (1:1) twice-daily for 6 weeks. The primary end point was percentage change from baseline in total sign score at week 6 based on in-person assessment. RESULTS: Crisaborole-treated participants had significantly reduced total sign score from baseline versus vehicle based on in-person (nondermatologist) assessment (-32.4% vs -18.1%, P = .0299) and central reader (dermatologists) assessment of photographs (-52.5% vs -10.3%, P = .0004). Efficacy according to success and improvement per Investigator's Global Assessment score and lesional percentage body surface area reached statistical significance based on central reader but not in-person assessments. Skin and subcutaneous tissue disorders were common all-causality treatment-emergent adverse events with crisaborole. LIMITATIONS: Small sample size and short treatment duration were key limitations. In-person assessment was not conducted by dermatologists. CONCLUSION: Crisaborole improved signs and symptoms of SD and was well tolerated. Central reader assessment represents a promising approach for siteless clinical research.

Towards a replacement therapy for stimulant betel quid dependence: A proof of concept study.

Stimulant betel quid (SBQ) containing Piper betle leaf (L), green unripe Areca catechu nut (AN) and the alkalizing agent, slaked lime, is an addictive, carcinogenic stimulant, with no pharmacotherapy, chewed by millions of people in the Asia/Pacific region. We compared the in vivo physiological profile of chewing (1) non-stimulant P. betle leaf+AN (LAN), (2) SBQ utilizing slaked lime and (3) a novel SBQ utilizing Mg(OH)2 , as an alkalizing agent, by measuring physiological parameters of intoxication and these were correlated with in vitro levels of alkaloids measured by UHPLC-MS/MS. Chewing LAN, which contains high levels of arecoline, had no stimulatory physiological effect. Chewing SBQ containing slaked lime or novel SBQ containing Mg(OH)2 , induced equivalent stimulatory physiological responses. In vitro, slaked lime hydrolyzed muscarinic esters in LAN while Mg(OH)2 did not. The physiological stimulation induced by chewing both SBQ and the lack of physiology to chewing LAN can be explained by changes in lipid solubility of phytochemicals induced by mouth pH during chewing of basic SBQ or acidic LAN. Since antiquity people have added slaked lime to SBQ to enhance absorption of phyto-chemicals across oral membranes to stimulate physiology. The same physiological changes can be induced by substituting slaked lime for less physically and chemically destructive bases. If attitudes regarding SBQ dependence can advance towards the more progressive attitudes already used to help smokers quit tobacco, modern chemistry has the potential to make chewing SBQ safer and quitting programs may become more accessible and efficacious.

Motivation communication training programme for healthcare professionals to support adherence in patients with diabetic foot ulcers: Proof of concept study.

Patients with diabetic foot ulcers have poor adherence to treatment recommendations. However, the most effective way to support adherence in this population is unknown. This study aimed to assess the preliminary effectiveness of a motivation communication training programme for healthcare professionals working with these patients, using theory and evidence-based strategies.A proof-of-concept study using a non-randomised, controlled before-and-after design. Six podiatrists took part in the motivation communication training programme. Pre-training, observation was undertaken to examine the communication style currently used by podiatrists in routine consultations. Patients' (n = 25) perceptions of podiatrist autonomy support, self-determination for limiting weight-bearing activity and average daily step count were also assessed. Post training, observations and patient measures were repeated with a different group of patients (n = 24). Observations indicated that podiatrists exhibited a more need-supportive communication style (e.g., taking time to understand patients' perspectives) after undergoing the training programme. Patients in the post-training group reported higher levels of autonomy support, while self-determination to limit weight-bearing activity remained unchanged. Although the post-training group had a lower average daily step count, the difference was not statistically significant. This is the first study to investigate implementation of motivation communication strategies in routine consultations with patients with diabetic foot ulcers. Results suggest that training can enhance healthcare professionals' motivation communication skills with potential for addressing adherence issues, however, a larger cluster randomised controlled trial is necessary to confirm this.

Proof of concept testing of a positive reference material for in vivo and in vitro sensitization testing of medical devices.

In vivo skin sensitization tests are required to evaluate the biological safety of medical devices in contact with living organisms to provide safe medical care to patients. Negative and positive reference materials have been developed for biological tests of cytotoxicity, implantation, hemolysis, and in vitro skin irritation. However, skin sensitization tests are lacking. In this study, polyurethane sheets containing 1 wt/wt % 2,4-dinitrochlorobenzene (DNCB-PU) were developed and evaluated as a positive reference material for skin sensitization tests. DNCB-PU sheet extracts prepared with sesame oil elicited positive sensitization responses for in vivo sensitization potential in the guinea pig maximization test and the local lymph node assay. Furthermore, DNCB-PU sheet extracts prepared with water and acetonitrile, 10% fetal bovine serum-containing medium, or sesame oil elicited positive sensitization responses as alternatives to animal testing based on the amino acid derivative reactivity assay, human cell line activation test, and epidermal sensitization assay, respectively. These data suggest that the DNCB-PU sheet is an effective extractable positive reference material for in vivo and in vitro skin sensitization testing in medical devices. The formulation of this reference material will lead to the development of safer medical devices that contribute to patient safety.

Post-mortem formation of ethanol: Is 1-propanol a reliable marker? A proof-of-concept study using an in vitro putrefactive environment setup.

Ethanol is the psychoactive substance identified most frequently in post-mortem specimens. Unfortunately, interpreting post-mortem ethanol concentrations can be difficult because of post-mortem alcohol redistribution and the possibility of post-mortem alcohol neogenesis. Indeed, in the time interval between death and sample collection, the decedent may be exposed to non-controlled environments for an extended period, promoting microbial colonization. Many authors report that in the presence of carbohydrates and other biomolecules, various species of bacteria, yeast, and fungi can synthesize ethanol and other volatile substances in vitro and in vivo. The aim of this study was to study the impact of several variables on microbial ethanol production as well as develop a mathematical model that could estimate the microbial-produced ethanol in correlation with the most significant consensual produced higher alcohol, 1-propanol. An experimental setup was developed using human blood samples and cadaveric fragments incubated under strictly anaerobic conditions to produce a novel substrate, "cadaveric putrefactive blood" mimicking post-mortem corpse conditions. The samples were analyzed daily for ethanol and 1-propanol using an HS-GC-FID validated method. The formation of ethanol was evaluated considering different parameters such as putrefactive stage, blood glucose concentration, storage temperature, and storage time. Statistical analysis was performed using the Mann-Whitney non-parametric test and simple linear regression. The results indicate that the early putrefactive stage, high blood glucose concentration, high temperature, and time of incubation increase microbial ethanol production. In addition, the developed mathematical equation confirms the feasibility of using 1-propanol as a marker of post-mortem ethanol production.

Porous microneedle arrays as promising tools for the quantification of drugs in the skin: a proof of concept study.

This study aimed to demonstrate the potential of using porous microneedles (PMNs) as a promising tool for the noninvasive quantification of topically applied pharmaceutical products. We fabricated a porous microneedle (PMN) from a blend of cellulose acetate and dimethyl sulfoxide by casting and phase separation; it was characterized using scanning electron microscopy, Raman spectroscopy, differential scanning calorimetry, and a Texture Analyzer. An ex vivo study was conducted as a proof-of-concept study to assess whether this PMN could be used to quantify drug absorption through the skin after the topical administration of two nonequivalent products of sodium ibuprofen (gel and dissolving microneedles). Three cellulose acetate formulations (PMN1: 37.5%, PMN-2: 44.4%, and PMN-3: 50%) were used to prepare PMN patches; subsequently, these were evaluated for their morphological and insertion properties. Only PMN-2 microneedle patches were chosen to continue with the ex vivo study. The ex vivo study results demonstrated that PMNs could absorb and release sodium ibuprofen (SDIB) and differentiate between two different SDIB topical products. This can be attributed to the porous and interconnected architecture of these microneedles. This developmental study highlights the potential success of such a tool for the quantification of dermal drug concentration and supports moving to in vivo tests.

Deep learning-based prediction of major arrhythmic events in dilated cardiomyopathy: A proof of concept study.

Prediction of major arrhythmic events (MAEs) in dilated cardiomyopathy represents an unmet clinical goal. Computational models and artificial intelligence (AI) are new technological tools that could offer a significant improvement in our ability to predict MAEs. In this proof-of-concept study, we propose a deep learning (DL)-based model, which we termed Deep ARrhythmic Prevention in dilated cardiomyopathy (DARP-D), built using multidimensional cardiac magnetic resonance data (cine videos and hypervideos and LGE images and hyperimages) and clinical covariates, aimed at predicting and tracking an individual patient's risk curve of MAEs (including sudden cardiac death, cardiac arrest due to ventricular fibrillation, sustained ventricular tachycardia lasting ≥30 s or causing haemodynamic collapse in <30 s, appropriate implantable cardiac defibrillator intervention) over time. The model was trained and validated in 70% of a sample of 154 patients with dilated cardiomyopathy and tested in the remaining 30%. DARP-D achieved a 95% CI in Harrell's C concordance indices of 0.12-0.68 on the test set. We demonstrate that our DL approach is feasible and represents a novelty in the field of arrhythmic risk prediction in dilated cardiomyopathy, able to analyze cardiac motion, tissue characteristics, and baseline covariates to predict an individual patient's risk curve of major arrhythmic events. However, the low number of patients, MAEs and epoch of training make the model a promising prototype but not ready for clinical usage. Further research is needed to improve, stabilize and validate the performance of the DARP-D to convert it from an AI experiment to a daily used tool.

Multilevel testing of constraints induced by structural equation modeling in fMRI effective connectivity analysis: A proof of concept.

In functional MRI (fMRI), effective connectivity analysis aims at inferring the causal influences that brain regions exert on one another. A common method for this type of analysis is structural equation modeling (SEM). We here propose a novel method to test the validity of a given model of structural equation. Given a structural model in the form of a directed graph, the method extracts the set of all constraints of conditional independence induced by the absence of links between pairs of regions in the model and tests for their validity in a Bayesian framework, either individually (constraint by constraint), jointly (e.g., by gathering all constraints associated with a given missing link), or globally (i.e., all constraints associated with the structural model). This approach has two main advantages. First, it only tests what is testable from observational data and does allow for false causal interpretation. Second, it makes it possible to test each constraint (or group of constraints) separately and, therefore, quantify in what measure each constraint (or, e..g., missing link) is respected in the data. We validate our approach using a simulation study and illustrate its potential benefits through the reanalysis of published data.