Test Protocol Research Articles

A comprehensive analysis of household air pollution due to traditional cooking in the himalayan belt

Abstract Household air pollution (HAP) and its health concerns are a significant challenge in the Indian subcontinent and other developing nations. Approximately 4.3 million deaths worldwide are attributed to indoor air pollution rather than outdoor air pollution, most of which occur in low- and middle-income countries. Traditional cookstoves, widely used in rural Himalayan areas of India, Nepal, and Pakistan, emit pollutants like particulate matter (PM), carbon monoxide (CO), and carbon dioxide (CO2). These stoves, which burn solid fuels such as wood, dung, charcoal, and agricultural waste, contribute to respiratory infections, cancer, premature mortality, and cardiovascular diseases. Improving biomass cookstoves can help reduce exposure to the harmful indoor air pollutants. This study evaluates household pollution levels in Uttarakhand, India, using direct data collection to determine the daily contaminant exposure. The findings show extremely high PM 2.5 and 10 emissions (2,100 μg/m³ and 5,000 μg/m³, respectively) due to inefficient cookstove design and incomplete fuel combustion. By comparing traditional and improved cookstoves using standardized testing protocols, the study also measures the efficiency and identifies the causes of high emissions. The results corroborated the hypothesis that traditional cookstoves have a very low thermal efficiency of ∼11 %, leading to the high emissions gathered from sensor data. This comparison provides specific insights into the reasons behind high emissions and suggests targeted improvements. The findings suggest potential improvements in cookstove efficiency, offering a foundation for further research and stakeholder involvement to enhance rural livelihoods in India.

Evaluation of a new protocol for rapid identification of Streptococcus pneumoniae in blood cultures using the modified bile solubility test: Gram staining is still standing.

This study aimed to evaluate a new protocol of the bile solubility test performed directly on the blood from positive blood culture bottles to identify Streptococcus pneumoniae rapidly. Seventy-five positive blood cultures (PBC) showing Gram-positive cocci in pairs or chains on Gram stain, including 32 S. pneumoniae isolates and three reference American Type Culture Collection (ATCC) isolates were included to evaluate the performance of a modified bile solubility test (MBST). One milliliter of blood from the PBC bottle was mixed with 0.5 mL of 10% desoxycholate or a saline solution. Both suspensions were analyzed after 10 min of incubation through a Gram stain to detect solubilization. This technique was compared with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry identification, performed on PBC following extraction or on colonies after short or standard incubation, and the optochin susceptibility test on colonies. The capsular serotypes were determined for all S. pneumoniae, and the Belgian National Reference Center confirmed the identification. All 32 clinical isolates and the ATCC isolate of S. pneumoniae were solubilized on the desoxycholate-treated slides, while the other species tested remained visually unchanged on both, the test and control slides. The MBST test demonstrated a 100% sensitivity and specificity with a mean turnaround time (TAT) of just 39 min, making it 14 h and 56 min faster than the optochin susceptibility test. This rapid variant of the bile solubility test appears to be a reliable method to identify S. pneumoniae directly from positive blood culture bottles, with a TAT of 39 min. It is a cost-effective, easy-to-perform, and time-efficient technique. Negative results should be interpreted cautiously, as they may result from mixed infections with S. pneumoniae and other Gram-positive cocci.

Real-World Retrospective Audit on the Use of the TechnoClone TECHNOSCREEN ADAMTS-13 Assay in the Diagnostic Process for Thrombotic Thrombocytopenic Purpura at LabPlus, New Zealand.

The TECHNOSCREEN ADAMTS-13 assay (ADSC) is a new lateral flow test which is simple and quick to perform, with a high negative predictive value (NPV); it may improve the diagnostic workflow for TTP. LabPlus in Auckland, New Zealand, performs all ADAMTS13 tests in the Auckland and Northland regions. The ADSC was used at LabPlus between 2022 and 2023 as part of a protocol where results of 0 IU/mL and 0.1 IU/mL were confirmed with the TECHNOZYM ADAMTS-13 Activity chromogenic ELISA assay (ADATS). The aim was to improve cost efficiency by reducing the need for the labour-intensive ADATS, particularly in low probability requests. This retrospective audit analyses the efficacy and efficiency of the testing protocol. All ADAMTS-13 tests performed in the year before the ADSC (March 2021-March 2022) and after the ADSC protocol was introduced (March 2022-March 2023) were collected from the LabPlus laboratory information system (LIS), and correlated with clinical information from the electronic health record. Statistical analysis was performed. Ninety-four test requests were audited. ADSC had an NPV of 100% on diagnostic samples. The protocol increased the median turn-around time (TAT) by 18 h (p = 0.01). If an ADSC of 0.1 IU/mL was taken as a negative, the median TAT was decreased by 17 h (p = 0.0003) in diagnostic samples from LabPlus adjacent hospitals. ADSC has a high NPV but did not improve TAT when used as part of a testing protocol for our central laboratory receiving samples from a large area.

The IPEDs assemblage: Tracing the entanglements of biomedicine, technology, enhancement and anti-doping policies in sport and society.

The US Anti-Doping Agency (USADA) and Ultimate Fighting Championship (UFC) recently ended their anti-doping partnership amidst controversy. We treat this decision, and the motivations underpinning it, as a means of exploring the complexities of anti-doping norms and the blurred lines between image and performance enhancing drug (IPED) use in sport and wider society. Drawing ideas from assemblage thinking, we analyse the evolving power dynamics surrounding IPED use, anti-doping policy, and the role of popular athletes in shaping societal perceptions of the use of, and potential harms associated with IPEDs. The study offers a case analysis of recent controversies in the UFC to investigate the entanglements of biomedicine, technology and celebrity culture in what we call the IPED assemblage. The 2023 termination of the USADA-UFC partnership has sparked debates about shifts in anti-doping standards, raising concerns about weaker testing protocols and perceptions of IPED normalisation. The case of Conor McGregor's injury recovery and alleged IPED use underscores the blurred lines between therapeutic and enhancement drug use within the IPED assemblage, challenging conventional distinctions between 'good' and 'bad' drugs in the context of sports management and anti-doping policy making. We highlight the inadequacy of current doping policies in responding to the IPED assemblage and highlight the need to shift public discourse to foster a more critical understanding of therapeutic and enhancement strategies to drive innovation in anti-doping frameworks.

A brief effective screening protocol for identifying cataract patients with binocular vision anomalies

BackgroundTo compare the effectiveness of a brief binocular vision screening protocol to a comprehensive examination for detecting binocular vision anomalies before and after cataract surgery.MethodsA comprehensive binocular vision test battery as a gold standard were administered on recruited patients before the first surgery and at the third visit after surgery on the second eye. A receiver operating characteristic (ROC) curve was plotted to illustrate the diagnostic ability of each test. In addition, a univariate logistic regression analysis was performed to further determine the contribution of each preoperative test to the prediction of pre- and post-surgical binocular vision anomalies.ResultsSignificant differences were shown for the difference in phoria from distance to near measured by the cover test (Area Under Curve [AUC] = 0.96, P < 0.01), step vergence testing of positive fusional vergence at distance (AUC = 0.71, P < 0.01) and near (AUC = 0.77, P < 0.01). The other tests did not show statistically significant differences. The ROC curve generated by combining the difference in distance and near phoria with positive fusional vergence at both distance and near demonstrated a more robust measure of diagnostic accuracy. (AUC = 0.98, P < 0.01).ConclusionDistance and near phoria difference measured by cover test has similar effectiveness as a comprehensive binocular vision testing protocol for the diagnosis of binocular vision anomalies. Distance and near positive fusional vergence measured by step vergence testing also have significant predictive value. A combination of the two tests is an outstanding screening protocol for binocular vision anomalies before cataract surgery.Trial registrationThe study was registered at ClinicalTrials.gov (NCT03592615, Date of registration: July 19, 2018).

High-Performance Fluorine-Lean Thin Aromatic Hydrocarbon Membranes Based on Polyvinylidene Fluoride for Hydrogen Fuel Cells

The impeding ban on per- and polyfluoroalkyl substances (PFAS) prompted researchers to focus on hydrocarbon-based materials as constituents of next-generation proton exchange membranes (PEMs) for polymer electrolyte fuel cells (PEFCs). Here, we report on the fuel cell performance and durability of fluorine-lean PEMs prepared by the post-sulfonation of co-grafted α-methylstyrene (AMS) and 2-methylene glutaronitrile (MGN) monomers into preirradiated 12 µm polyvinylidene fluoride (PVDF) base film. The membranes were subjected to two distinctly different accelerated stress test (AST) protocols performed at open-circuit voltage (OCV): the US Department of Energy-similar chemical AST (90 °C, 30% relative humidity (RH), H2/air, 1 bara), developed originally for perfluoroalkylsulfonic acid (PFSA) membranes, and the high relative humidity AST (80 °C, 100% RH, H2/O2, 2.5 bara), designed for aromatic hydrocarbon membranes. We found that doping the grafted membranes with a metalated porphyrin antioxidant can simultaneously reduce membrane aging and improve fuel cell performance.

A New Era in Federal Quarantine and State Certification Diagnostics at Clean Plant Centers in the USA.

Quarantine and certification programs exist to prevent the entry or spread of harmful pests and pathogens into agricultural systems. Their common objective is to identify pathogen-free source material through the application of validated testing methods for subsequent release for propagation. Tests must be accurate, efficient and cost-effective. In recent decades, the best tests have been biological assays in conjunction with PCR testing. High throughput sequencing (HTS) has now become a reliable and cost-effective diagnostic method having greater accuracy and efficiency than biological assays. In this article, we review the role of clean plant centers in quarantine and certification programs, as well as the process by which HTS was evaluated as a testing method to replace biological assays for screening source material. The data from this evaluation included a side-by-side comparison of HTS and biological assays for cultivars of grapevine, Prunus and rose, and intra- and inter-laboratory validations of an HTS protocol. Based on the results of these evaluations, in 2021 USDA-APHIS and several state regulatory agencies accepted the use of HTS and quantitative polymerase chain reaction (qPCR) to test new introductions of source material, replacing biological indexing. This new protocol requires testing at two timepoints within at least a six-month interval and a dormancy separating the two tests. Under ideal conditions, testing can be completed in 18-24 months with subsequent release from quarantine of plant material that has tested negative for regulated pathogens. This new testing protocol has a profound impact on quarantine and certification programs, facilitating quicker access of stakeholders to clean materials for propagation and increasing the number of pathogens that are detected, and even discovered, with reduced cost, effort, and time.

Rapid virucidal activity of an air sanitizer against aerosolized MS2 and Phi6 phage surrogates for non-enveloped and enveloped vertebrate viruses, including SARS-CoV-2.

An air sanitizer was evaluated using an aerobiology protocol, compliant with the U.S. Environmental Protection Agency's Air Sanitizer Guidelines, for virucidal activity against bacteriophages Phi6 and MS2 (used as surrogates for enveloped and non-enveloped human pathogenic viruses). The phages were suspended in a medium containing a tripartite soil load simulating body fluids and aerosolized using a six-jet Collison nebulizer in an enclosed 25 m3 aerobiology chamber at 22 ± 2°C and 50 ± 10% relative humidity. The air sanitizer was sprayed into the chamber for 30 s. Viable phages in the air were captured directly, in real time, on host bacterial lawns using a slit-to-agar sampler. Reductions in viable phage concentration ≥3.0 log10 (99.9%) were observed after a mean exposure of 3.6 min for Phi6, suggesting efficacy against enveloped viruses (e.g., SARS-CoV-2, influenza, and RSV), and ~10.6 min for MS2, suggesting virucidal efficacy for non-enveloped viruses (e.g., noroviruses and rhinoviruses). This targeted air sanitization approach represents an important non-pharmaceutical public health intervention with virucidal efficacy against airborne viral pathogens.IMPORTANCEAirborne viruses are implicated in the transmission indoors of respiratory and enteric viral infections. Air sanitizers represent a non-pharmaceutical intervention to mitigate the risk of such viral transmission. We have developed a method that is now an ASTM International standard (ASTM E3273-21) as well as a test protocol approved by the U.S. EPA to evaluate the efficacy of air sanitizing sprays for inactivating airborne MS2 and Phi6 bacteriophage (used as surrogates for non-enveloped and enveloped human pathogenic viruses, respectively). The test phages were individually suspended in a soil load and aerosolized into a room-sized aerobiology chamber maintained at ambient temperature and relative humidity. Reductions in viable phage concentration ≥3.0 log10 (99.9%) were observed after a mean exposure of 3.6 min for Phi6, suggesting efficacy against enveloped viruses (e.g., SARS-CoV-2; influenza; RSV), and ~10.6 min for MS2, suggesting virucidal efficacy for non-enveloped viruses (e.g., noroviruses and rhinoviruses). The data suggest the utility of the air sanitizer for mitigating the risk of indoor viral transmission during viral pandemics and outbreaks.

Model-driven exploration of poro-viscoelasticity in human brain tissue: be careful with the parameters!

The brain is arguably the most complex human organ and modelling its mechanical behaviour has challenged researchers for decades. There is still a lack of understanding on how this multiphase tissue responds to mechanical loading and how material parameters can be reliably calibrated. While previous viscoelastic models with two relaxation times have successfully captured the response of brain tissue, the Theory of Porous Media provides a continuum mechanical framework to explore the underlying physical mechanisms, including interactions between solid matrix and free-flowing interstitial fluid. Following our previously published experimental testing protocol, here we perform finite element simulations of cyclic compression-tension loading and compression-relaxation experiments on human brain white and gray matter specimens. The solid volumetric stress proves to be a crucial factor for the overall biphasic tissue behaviour as it strongly interferes with porous effects controlled by the permeability. An inverse parameter identification reveals that poroelasticity alone is insufficient to capture the time-dependent material behaviour, but a poro-viscoelastic formulation captures the response of brain tissue well. We provide valuable insights into the individual contributions of viscous and porous effects. However, due to the strong coupling between porous, viscous, and volumetric effects, additional experiments are required to reliably determine all material parameters.

Slovak database of speech affected by neurodegenerative diseases

A new Slovak speech database EWA-DB was created for research purposes aimed at early detection of neurodegenerative diseases from speech. It contains 1649 speakers performing various speech and language tasks, such as sustained vowel phonation, diadochokinesis, naming and picture description. The sample of speakers consists of individuals with Alzheimer’s disease, mild cognitive impairment, Parkinson’s disease, and healthy controls. In this article we describe the EWA-DB development process, the language and speech task selection, patient and healthy control recruitment, as well as the testing and recording protocol. The structure and content of the database and file formats are described in detail. We assume that the presented database could be suitable for the development of automatic systems predicting the diagnoses of Alzheimer’s disease, mild cognitive impairment, and Parkinson’s disease from language and speech features.

Evaluating the Implementation and Impact of BRAF Reflex Mutation Testing in Melanoma, Lung, and Colorectal Cancers.

Reflex molecular testing, the process of profiling specimens at diagnosis, is emerging in oncology, allowing for prompt therapy initiation, and potentially improving outcomes. This study evaluates the impact of reflex BRAF testing on treatment timelines and outcomes in melanoma, lung and colorectal cancers at the McGill University Health Center (MUHC). A retrospective chart review was conducted at the MUHC. The study included patients with melanoma, lung, and colorectal cancers who underwent BRAF testing from 2017 to 2022. Data on demographics, cancer type, stage, test ordering specialist, testing method, and treatment outcomes were extracted. Statistical analyses included descriptive and multivariate regression analyses. 518 BRAF molecular tests were performed, with 173 patients meeting the inclusion criteria [median age 72 (IQR 60-80 years), 46.2% female]. Of these, 75.7% had melanoma, 23.7% colorectal cancer and 0.58% lung cancer. Pathologists ordered 71.1% of BRAF tests, primarily relying on immunohistochemistry. By 2022, all BRAF results were available before oncology consultations. Patients with pre-consultation BRAF results were more likely to receive targeted therapy (59.4% vs 36.4%). The availability of BRAF test results was associated with quicker treatment initiation and better alignment of therapy with mutation status. This study underscores the success of the pathology team at MUHC in implementing reflex BRAF mutation testing, enhancing clinical care by ensuring the timely availability of test results. Delays in testing may adversely affect clinical decision-making and therapy selection, highlighting the need for standardized reflex testing protocols across Canada to optimize patient outcomes in melanoma, lung, and colorectal cancers.

Analysis of real world FRα testing in ovarian, fallopian tube, and primary peritoneal cancers

BackgroundEpithelial ovarian cancer (EOC) remains a significant challenge in gynecologic oncology, particularly in the context of platinum-resistant disease. Mirvetuximab soravtansine (MIRV), was approved after trials revealed favorable response and survival outcomes. MIRV targets folate receptor alpha (FRα), a cell-surface receptor that is overexpressed in EOC and has been associated with aggressive disease phenotypes. MethodsThis retrospective study analyzed 425 patient samples tested for FRα using the VENTANA® FOLR1 RxDx immunohistochemical assay. The patient cohort included cases with high grade serous carcinoma predominantly, tested across various anatomical sites. Statistical analysis examined the correlation between FRα positivity and clinical parameters such as tumor site and histology. ResultsFRα was highly expressed in 36.3 % of the cases, with a significant association between FRα positivity and high grade serous ovarian histology. Tumor samples from the ovary, fallopian tube, adnexa, and dominant pelvic masses showed higher FRα positivity compared to metastatic sites (positive rates of 44.4 % vs 32.5 %, p = 0.02), highlighting the potential influence of tumor origin on expression of FRα. Time between sample collection and testing did not impact FRα expression, with sample testing spread over a median of 19.5 months post-collection. Eight patients had more than one specimen tested, of which 3 (37.5 %) had discordant results when a subsequent specimen was tested. ConclusionOur results highlight a need for standardized protocols for FRα testing to ensure accurate biomarker evaluation across varied clinical settings. The heterogeneity in FRα expression, influenced by tumor histology and anatomical origin, warrant further investigation to optimize therapeutic outcomes. Prior presentationPreliminary findings from this study were previously presented in poster format at the Society of Gynecologic Oncology 2024 Annual Metting. We confirm that the submission complies with the journal requirements.

An In vitro Caco2‐Based Model for Measuring Intestinal Bioadhesion Comparable to Ex vivo Models

This study presents an in vitro model using Caco‐2 cells that can mimic the bioadhesion properties of the human intestinal epithelium, aiming to reduce the use of animal tissues, in line with the 3Rs principle—replacement, reduction, and refinement. Specifically, a texture analyzer was used to assess the bioadhesive strength of hydrogels (i.e., alginate (Alg), chitosan (Chit), and gelatin (Gel)) under various applied forces (20–200 mN) and contact times (120–420 s). The results demonstrate that the in vitro model effectively predicts the bioadhesive strength of the tested hydrogels to ex vivo tissues (i.e., from mice, sheep, and pigs), including the effects of applied force and contact time. Also provided is an analysis of the effect of microvilli morphology on bioadhesion where an inverse relationship was observed between microvilli linear density and bioadhesion strength, explaining the variability in results across animal models. This Caco‐2‐based model offers a practical, accessible, and cost‐effective alternative to current ex vivo methods used for measuring bioadhesion fracture strength. It can be integrated into standardized testing protocols, providing a more ethical and scientifically robust approach to advancing bioadhesive drug delivery system research.

Upper Airway Sensory Testing in Dysphagia - Implications for Clinical Practice and Future Research Directions.

Adequate upper airway (oral, pharyngeal and laryngeal) sensation is crucial for safe and efficient swallowing and airway protection. Despite its importance, methods of upper airway sensory testing for individuals with dysphagia remain poorly defined. The aim of this study was to summarise and appraise current methods of upper airway sensory testing to inform dysphagia clinical practice and future research directions. A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies that reported a method of upper airway sensory testing in individuals with dysphagia were included. Of the 1187 studies identified and screened, 54 met the inclusion criteria. Four types of upper airway sensory testing were reported: Flexible Endoscopic Evaluation of Swallowing with Sensory Testing (n = 31), Cough Reflex Testing (n = 22), Gag Reflex Testing (n = 5) and Gustatory (taste) Testing (n = 2). Indeterminate "tests of sensory function" (n = 2) were also reported. Variability in methods was evident across studies and reporting was insufficient for reliable replication. This review provides a comprehensive overview of methods of upper airway sensory testing in the dysphagia literature for dysphagia clinicians and researchers. The results indicate a need to develop a valid and reliable upper airway sensory testing protocol for individuals with dysphagia to improve assessment and targeted treatments.

A Comparison of Three Protocols for Determining Barbell Bench Press Single Repetition Maximum, Barbell Kinetics, and Subsequent Measures of Muscular Performance in Resistance-Trained Adults

Background: One repetition maximum (1RM) is a vital metric for exercise professionals, but various testing protocols exist, and their impacts on the resulting 1RM, barbell kinetics, and subsequent muscular performance testing are not well understood. This study aimed to compare two previously established protocols and a novel self-led method for determining bench press 1RM, 1RM barbell kinetics, and subsequent muscular performance measures. Methods: Twenty-four resistance-trained males (n = 12, 24 ± 6.1 years) and females (n = 12, 22.5 ± 5.5 years) completed three laboratory visits in a randomized crossover fashion. During each visit, a 1RM was established using one of the three protocols followed by a single set to volitional fatigue using 80% of their 1RM. A Sex:Protocol repeated measures ANOVA was used to determine the effects of sex and differences between protocols. Results: No significant differences were observed between the protocols for any measure, except for 1RM peak power (p = 0.036). Post hoc pairwise comparisons failed to identify any differences. Males showed significantly higher 1RM, average, and peak power (ps &lt; 0.001), while females demonstrated a greater average concentric velocity (p = 0.031) at 1RM. Conclusions: These data suggest the protocol used to establish 1RM may have minimal impact on the final 1RM, 1RM barbell kinetics, and subsequent muscular endurance in a laboratory setting.

Stress test protocols applied without treadmill and bicycle ergometer: procedures and interpretation

The article highlights the possibility of application of exercise tests without special equipment. The methodological features of conducting tests and their interpreting options are shown. Changed body position tests have been updated. The definitions of stress tests and exercise tests have been clarified. A classification of ergometers and indicators of monitored parameters has been worked out. Examples of medical reports are given. The application possibilities of stress tests were considered in real clinical practice at the stages of treatment and rehabilitation of patients with a wide range of nosologies. Tables for independently determining the exercise test results are presented. The methods can be used in pediatric practice. The article is addressed to a wide range of practitioners and functional diagnostics specialists.

Assessment of standard test procedures applied to calcium sulfoaluminate based cements

Cements containing calcium sulfoaluminate (CSA) have reported excellent characteristics at both early and later ages. However, there are a number of studies reporting poor durability when compared with Portland cement (PC). Durability tests are used as an indicator for service life, and thus the viability of a cement system relies on its performance in these tests. Test methods often assume a sufficient maturity based on extensively tested PC systems; however, slower hydrating binder assemblages and variable chemistries can be severely underestimated when tested at the default 28 days. For example, a belitic CSA (BCSA) cement tested at this time will fail to account for later-stage hydration products that can improve the durability of the system. Tests on the durability of BCSA cements beyond 28 days of curing are sparsely covered in the literature, although in each study the results have shown a marked improvement in durability performance – a characteristic paralleled by other slow-hydrating binders such as fly ash composite cements. The use of an equivalent cement hydration/maturity in testing protocols is proposed, which could be considered a baseline for subsequent improvements that can be made with regard to how alternative binder systems are tested. A call to action for the cement community is outlined to (a) understand what tests are actually testing at a chemical level, (b) develop a ‘cure test’ to assess maturity and (c) undertake round-robin testing.

Electroencephalographic power ratio and peak frequency difference associate with central sensitization in chronic pain.

Central sensitization, or increased responsiveness of the central nervous system to sensory input, is present in many chronic pain patients. Clinically, it is detected through subjective, patient-reported measures. There is a need for reliable, direct measurements of neural response to controlled stimuli to quantify neuronal dysfunction in pain. The goal of this work is to investigate cortical activity, recorded via electroencephalogram (EEG), during objective and calibrated painful stimulation in chronic pain patients.&#xD;Approach. Chronic pain patients (N=8) and healthy controls (N=8) participated in this study. We recorded electroencephalography (EEG) at rest (baseline) and during evoked pain tasks, including thermal and mechanical stimuli. The evoked pain was applied following the quantitative sensory testing (QST) protocol, which is a research technique that applies objective, calibrated painful stimuli. &#xD;Main results. Peak alpha frequency at rest was significantly lower in chronic pain patients compared to healthy controls (p<0.0002), while EEG alpha/theta and alpha/beta power ratios at rest were higher in patients (p<0.0002). During thermal QST, these power ratios decreased in patients and increased in controls (p<0.0002 for both). During mechanical QST, power ratios decreased or did not change. Furthermore, the peak theta-beta frequency difference at baseline was significantly lower in patients compared to controls (p<0.0002). During thermal QST, this difference increased in patients and decreased in controls; during mechanical QST, this difference increased in both patients and controls (p<0.0002). Functional connectivity analysis showed that controls had greater baseline theta connectivity strength that increased during mechanical QST (p<0.0002).&#xD;Significance. This work demonstrates differential patterns of EEG activity at rest and during acute painful stimulation in chronic pain patients compared to healthy controls. These measures may quantify an individual's tendency to experience chronic pain and central sensitization and serve as diagnostic biomarkers.

Cooperative Atomically Dispersed Fe-N4 and Sn-Nx Moieties for Durable and More Active Oxygen Electroreduction in Fuel Cells.

One grand challenge for deploying porous carbons with embedded metal-nitrogen-carbon (M-N-C) moieties as platinum group metal (PGM)-free electrocatalysts in proton-exchange membrane fuel cells is their fast degradation and inferior activity. Here, we report the modulation of the local environment at Fe-N4 sites via the application of atomic Sn-Nx sites for simultaneously improved durability and activity. We discovered that Sn-Nx sites not only promote the formation of the more stable D2 FeN4C10 sites but also invoke a unique D3 SnNx-FeIIN4 site that is characterized by having atomically dispersed bridged Sn-Nx and Fe-N4. This new D3 site exhibits significantly improved stability against demetalation and several times higher turnover frequency for the oxygen reduction reaction (ORR) due to the shift of the reaction pathway from a single-site associative mechanism to a dual-site dissociative mechanism with the adjacent Sn site facilitating a lower overpotential cleavage of the O-O bond. This mechanism bypasses the formation of the otherwise inevitable intermediate that is responsible for demetalation, where two hydroxyl intermediates bind to one Fe site. As a result, a mesoporous Fe/Sn-PNC catalyst exhibits a positively shifted ORR half-wave potential and more than 50% lower peroxide formation. This, in combination with the stable D3 site and enriched D2 Fe sites, significantly enhanced the catalyst's durability as demonstrated in membrane electrode assemblies using complementary accelerated durability testing protocols.

Efficient and accurate determination of crack propagation rate without unloading-induced crack closure

The accurate delineation of the fatigue crack growth rate (da/dN) model, encompassing the short crack stage, assumes paramount importance in the operation and maintenance of transportation vehicles such as aircraft. Nonetheless, the determination of the da/dN encounters challenges, notably crack closure engendered by unloading observations on the specimen and the attendant issue of exorbitant test expenditures due to low load amplitude (ΔP), thereby impeding the precise establishment of the da/dN model, particularly in the short crack stage. Hence, this study initially posits a novel crack observation methodology employing a self-engineered stress transfer apparatus to sustain the stress (σ) on the specimen at its closure stress (σcl) level post-unloading, thus mitigating the impact of crack closure on crack observation and augmenting the accuracy of da/dN curve determination. Subsequently, building upon this innovation, a fatigue crack propagation (FCP) test protocol tailored for the short crack stage is advanced, principally by substantially augmenting ΔP to surmount the cost constraints of the test, thereby broadening the scope of da/dN curve determination to 10−8 mm/cycle. Lastly, premised on the acquisition of high precision and comprehensive da/dN curves, a da/dN model is posited by integrating with the extant da/dN model, which can comprehensively and precisely delineate the FCP behavior across the entire crack growth spectrum, particularly in the short crack stage. Illustratively demonstrated through a case study on 42CrMo steel crankshaft, a fatigue life (Nf) prediction investigation conducted based on this da/dN model substantiates its efficacy in accurately assessing the FCP behavior of crankshaft materials vis-à-vis existing models, thereby reducing the Nf prediction error by 14.64 %.