Threshold Of Reactivity Research Articles

The use of biologics in food allergy management.

Patients and families living with food allergy may experience significant burdens, including social isolation, impaired quality of life, and anxiety. Allergists/immunologists play a critical role in educating families living with food allergies about risk, particularly with regard to the rarity of fatal food allergy. Appropriate risk framing can greatly decrease the fear-based burden of disease. In 2024, an increasing complex fabric of food allergy treatments has emerged that includes oral immunotherapy (OIT), sublingual immunotherapy (SLIT), and omalizumab, with the promise of additional treatments, including epicutaneous immunotherapy and oral mucosal immunotherapy in the near future. Younger children may be most likely to benefit from OIT and SLIT, with some evidence that suggests the possibility of an immunomodulatory effect. Omalizumab, approved in 2024 for use in conjunction with strict avoidance, increases the threshold of reactivity before a moderate-to-severe reaction for many, but not all, patients. There is no evidence to date that omalizumab has an immunomodulatory effect, and young children treated with omalizumab monotherapy may bear a lost opportunity cost from possible immunomodulation would they have been treated with OIT or SLIT instead; however, within a shared decision-making paradigm, beyond label use of omalizumab may include treatment with OIT or SLIT. Fortunately, the co-evolution of shared decision-making with modern food allergy treatments will facilitate the critical preference-sensitive care that must be characteristic of all decisions surrounding active food allergy management.

Antinociceptive Behavior, Glutamine/Glutamate, and Neopterin in Early-Stage Streptozotocin-Induced Diabetic Neuropathy in Liraglutide-Treated Mice under a Standard or Enriched Environment

Diabetic neuropathy (DN) is a common complication of long-lasting type 1 and type 2 diabetes, with no curative treatment available. Here, we tested the effect of the incretin mimetic liraglutide in DN in mice with early-stage type 1 diabetes bred in a standard laboratory or enriched environment. With a single i.p. injection of streptozotocin 150 mg/kg, we induced murine diabetes. Liraglutide (0.4 mg/kg once daily, i.p. for ten days since the eighth post-streptozotocin day) failed to decrease the glycemia in the diabetic mice; however, it alleviated their antinociceptive behavior, as tested with formalin. The second phase of the formalin test had significantly lower results in liraglutide-treated mice reared in the enriched environment vs. liraglutide-treated mice under standard conditions [2.00 (0.00–11.00) vs. 29.00 (2.25–41.50) s, p = 0.016]. Liraglutide treatment, however, decreased the threshold of reactivity in the von Fray test. A significantly higher neopterin level was demonstrated in the diabetic control group compared to treatment-naïve controls and the liraglutide-treated diabetic mice (p < 0.001). The glutamine/glutamate ratio in both liraglutide-treated groups, either reared under standard conditions (p = 0.003) or an enriched environment (p = 0.002), was significantly higher than in the diabetic controls. This study demonstrates an early liraglutide effect on pain sensation in two streptozotocin-induced diabetes mouse models by reducing some inflammatory and oxidative stress parameters.

Development of Dual Cooperative Multi‐Urea Catalysts for Henry Reaction

AbstractA dual cooperative multi‐urea catalyst for Henry reaction was developed in which four urea groups were introduced into a rigid and rotatable framework. The tetraurea catalyst 1 showed higher activity for Henry reaction than its analogues, close‐bisurea 2 or distal‐bisurea 3 with two urea units, demonstrating additional cooperativity between the two substrate‐pinching catalytic sites of tetraurea 1. Addition of the reaction product to the reaction system resulted in a small amount of further activation. This work would provide a basis for new cooperative molecular catalysts, leading to a high degree of regulation based on allosteric cooperativity, e.g. with a distinct ON/OFF threshold for reactivity, or feedback activation by using the product as a reaction template.

A Neural Network Potential Energy Surface and Quantum Dynamics Study of Ca(1S) + H2(v 0 = 0, j 0 = 0) → CaH + H Reaction.

The reactive collision between Ca and H2 molecules has attracted great interest experimentally due to the key role of the product CaH molecule in the field of astrophysics and cold molecules. However, quantum dynamics calculations for this system have not been reported due to the lack of a global potential energy surface (PES). Herein, a globally accurate PES of the ground-state CaH2 is developed by combining 11365 high-level ab initio points and permutation invariant polynomial neural network method. Based on the newly constructed PES, the state-to-state quantum dynamics calculations for the Ca(1S) + H2 (v 0 = 0, j 0 = 0) → CaH + H reaction are carried out using the time-dependent wave packet method. The dynamic results reveal that the reaction follows the complex-forming mechanism near the reactive threshold, whereas both the indirect insertion mechanism and direct abstraction mechanism have effects at higher collision energies. The newly constructed PES can be used to further study the influence of isotope substitution, rovibrational excitation, and spatial orientation of reactant molecules on reaction dynamics.

Identifying thresholds of reaction for different foods.

Current food allergy management universally treats all patients with food allergy as being at risk for anaphylaxis (with the exception perhaps of pollen food allergy syndrome). Thus, patients are told to avoid the allergenic food in all potentially allergic forms and amounts. However, research over the past 2 decades has shown that many patients will tolerate small amounts of the allergen without any allergic reaction. Thus, if one were able to identify the threshold of reactivity, this could change management. At the population level, establishing levels at which the vast majority of patients (e.g., 95%) do not react could have public health ramifications, such as altering labeling laws. At the individual patient level, personal threshold levels could determine avoidance strategies, affect quality of life, and alter treatment decisions, e.g., oral immunotherapy starting doses. In this review, threshold data for various allergens and their potential effect on the management of the patient with food allergy are examined.

Cytomegalovirus Matching in Deceased Donor Kidney Allocation: Results From a U.S. National Simulation Model.

Cytomegalovirus (CMV) infects >60% of adults and can pose an independent risk factor for allograft loss and mortality in solid organ transplant recipients. The purpose of this study is to evaluate the impact of a nationwide implementation of CMV seromatching (donor/recipient: D-/R- and D+/R+) in the U.S. deceased donor kidney allocation system (KAS). Adult candidates on the U.S. kidney-only transplant waiting list and deceased donor kidneys offered to the U.S. transplant centers were considered. A discrete-event simulation model, simulating the pre-COVID-19 period from January 1, 2015, to January 1, 2018, was used to compare the performances of currently employed KAS-250 policy (without CMV matching) to various simulated CMV matching policies parameterized by calculated panel reactive antibody exception threshold. Outcomes included CMV serodistribution, waiting time, access to transplantation among various groups, transplant rate, graft survival, kidney discard rate, and antigen-mismatch distribution, stratified by CMV serostatus. CMV matching policy with a calculated panel reactive antibody exception threshold of 50% (namely, the CMV">50%" policy) strikes a better balance between benefits and drawbacks of CMV matching. Compared with KAS-250, CMV">50%" reduced CMV high-risk (D+/R-) transplants (6.1% versus 18.1%) and increased CMV low-risk (D-/R-) transplants (27.2% versus 13.1%); increased transplant rate for CMV R- patients (11.54 versus 12.57) but decreased for R+ patients (10.68 versus 10.48), yielding an increase in aggregate (11.09 versus 10.94); and reduced mean time to transplantation (by 6 wk); and reduced kidney discard rate (25.7% versus 26.2%). Our findings underscore the feasibility and potential advantages of a nationwide CMV seromatching policy in kidney transplantation.

Transcranial Doppler cerebrovascular reactivity: Thresholds for clinical significance in cerebrovascular disease.

Thresholds for abnormal transcranial Dopplercerebrovascular reactivity (CVR) studies are poorly understood, especially for patients withcerebrovascular disease. Using a real-world cohort with cerebral arterial stenosis, we sought to describe a clinically significant threshold for carbon dioxide reactivity (CO2R) and vasomotor range (VMR). CVR studies were performed during conditions of breathing room air normally, breathing 8% carbon dioxide air mixture, and hyperventilation.The mean and standard deviation (SD) of CO2R and VMR were calculated for the unaffected side in patients with unilateral stenosis; a deviation of 2SDs below the mean was chosen as the threshold for abnormal. Receiver operating characteristic (ROC) curves for both sides for patients with unilateral and bilateral stenosis were evaluated for sensitivity (Sn) and specificity (Sp). A total of 133 consecutive CVR studies were performed on 62 patients with stenosis with mean±SDage 55±16years. Comorbidities included hypertension (60%), diabetes (15%), stroke (40%), and smoking (35%). In patients with unilateral stenosis, mean±SD CO2R for the unaffected side was 1.86±0.53%, defining abnormal CO2R as <0.80%. Mean±SD CO2R for the affected side was 1.27±0.90%. TheCO2R threshold predicted abnormal acetazolamide single-photon emission computed tomography (SPECT) (Sn=.73, Sp=.79), CT/MRI perfusion abnormality (Sn=.42, Sp=.77), infarction on MRI (Sn=.45, Sp=.76), and pressure-dependent exam (Sn=.50, Sp=.76). For the unaffected side, mean±SD VMR was 39.5±15.8%, defining abnormal VMR as <7.9%. For the affected side, mean±SD VMR was 26.5±17.8%. The VMR threshold predicted abnormal acetazolamide SPECT (Sn=.46, Sp=.94), infarction on MRI (Sn=.27, Sp=.94), and pressure-dependent exam (Sn=.31, Sp=.90). In patients with multiple vascular risk factors, a reasonable threshold for clinically significant abnormal CO2R is <0.80% and VMR is <7.9%. NoninvasiveCVR may aid in diagnosing and risk stratifying patients withstenosis.

SARS-CoV-2 Seroprevalence in Children under 5 Years Old-A Regional Seroepidemiological Study.

Background and Objectives: The aim of this research was to assess the spread of SARS-CoV-2 infection; the study was motivated by parental hesitancy regarding child vaccination, and the potential passive immunity of infants acquired through breastfeeding from mothers vaccinated against COVID-19 or infected with SARS-CoV-2. Materials and Methods: We quantified the anti-SARS-CoV-2 immunoglobulin G (IgG) titer in the serum of 743 children under 5 years old, hospitalized between 1 August 2022, and 15 September 2023. Results: Among the participants, 52.76% had an anti-SARS-CoV-2 IgG titer that exceeded the reactivity threshold of the kit used, with an average of 1558.01 U/mL across the entire group. By age-specific categories, SARS-CoV-2 antibody prevalence was 43.04% for 0-12 months, 42.22% for 12-24 months, 61.67% for 24-36 months, 65.17% for 36-48 months, and 68.55% for 48-59 months. Gender analysis revealed 55.32% male participants, with a 52.07% seropositivity rate. Notably, IgG titer correlated positively with the child's age. Gender, admission diagnosis, and emergency department presentation were not variation factors of the IgG titer. Conclusions: The majority of children in the study group demonstrated IgG against SARS-CoV-2, and this rate increased with the child's age. Also, the IgG titer increased with the child's age.

Assessing the health risks of chemicals in a company supplying chemicals to drilling rigs in Southern Iran using COSHH, SHEM-SAM, and SQRA methods.

Chemical industries are among the process industries and cause many risks. The present research aimed to analyze the health risks of a chemical warehouse of drilling rigs chemical Supply Company based on COSHH (Control of Substances Hazardous to Health), CHEM-SAM (Chemical Risk Management Self-Assessment Model), and SQRA (Subjective Quantified Risk Assessment) methods in 2021. The information was collected based on document review, MSDS of chemicals, processes, employees, and chemical exposure. Flammability, toxicity, allergy-causing, corrosivity, reactivity, LD50, and permissible thresholds of chemicals were also collected. The present research results showed that out of 59 main chemicals in the operational processes of the chemical warehouse of drilling rigs, 14 chemicals are flammable, 22 cause allergy responses, and three can cause death if inhaled. According to the results of the CHEM-SAM method, the employees and people outside the organization are at medium and low chemical risk based on the current management of the chemical warehouse, respectively. The results of the COSHH health assessment showed that chemicals had low, medium, high, and very high risk in 31, 13, 12, and 3 cases, respectively. The high-risk cases consisted of Ammonium Nitrate، Caustic Soda, and Poly.Aluminum.Chloride. Health risk assessment was also performed using the SQRA method, and results showed that chemicals have a very low, low, medium, high, and very high risk in 27, 12, 8, 9, and 3 cases, respectively. The results showed that the adverse health effects of chemical exposure in the drilling industry are alarming. Employees of different sectors of oil and gas industries are exposed to chemicals.

Adaptive transient overvoltage control strategy for wind farm based on data‐driven

AbstractTo achieve the transient overvoltage suppression of doubly fed induction generator (DFIG) terminals and the point of common coupling (PCC) in the wind farm (WF), an adaptive overvoltage control strategy based on data‐driven approach is proposed. Firstly, the PCC reactive power demand and DFIG overvoltage threshold are derived, respectively. Secondly, three regression models are developed through surface fitting to determine three variables: the maximum overvoltage of each DFIG, the PCC maximum overvoltage, and the reactive power demand of each DFIG. Subsequently, the K‐means clustering method is adopted to group all DFIGs, and then the reactive power requirement of the PCC is proportionally distributed to each group of DFIGs. Lastly, a coordinated control strategy of DFIGs and static var generator (SVG) is designed based on the values of three regression models, which can adaptively adjust the reactive power absorbed by each DFIG and SVG. In particular, the de‐load control is adopted to enlarge the maximum reactive power capacity of DFIG. The simulation results show that the proposed control strategy can timely and effectively restore the transient overvoltage of the wind farm to the normal range during the gird failure, ensuring the stable operation of the wind farm.

QuantiFERON-CMV as a Predictor of CMV Events During Preemptive Therapy in CMV-seropositive Kidney Transplant Recipients.

Prevention of cytomegalovirus (CMV) infection after kidney transplantation is costly and burdensome. Given its promising utility in risk stratification, we evaluated the use of QuantiFERON-CMV (QFCMV) and additional clinical variables in this prospective cohort study to predict the first clinically significant CMV infection (CS-CMV, ranging from asymptomatic viremia requiring treatment to CMV disease) in the first posttransplant year. A cost-effectiveness analysis for guided prevention was done. One hundred adult kidney transplant recipients, CMV IgG + , were given basiliximab induction and maintained on steroid/mycophenolate/tacrolimus with weekly CMV monitoring. Thirty-nine patients developed CS-CMV infection (viral syndrome, n = 1; end-organ disease, n = 9; and asymptomatic viremia, n = 29). A nonreactive or indeterminate QFCMV result using the standard threshold around day 30 (but not before transplant) was associated with CS-CMV rates of 50% and 75%, respectively. A higher QFCMV threshold for reactivity (>1.0 IU interferon-γ/mL) outperformed the manufacturer's standard (>0.2 IU interferon-γ/mL) in predicting protection but still allowed a 16% incidence of CS-CMV. The combination of recipient age and type of donor, along with posttransplant QFCMV resulted in a prediction model that increased the negative predictive value from 84% (QFCMV alone) to 93%. QFCMV-guided preemptive therapy was of lower cost than preemptive therapy alone ( P < 0.001, probabilistic sensitivity analysis) and was cost-effective (incremental net monetary benefit of 210 USD) assuming willingness-to-pay of 2000 USD to avoid 1 CMV disease. Guided CMV prevention by the prediction model with QFCMV is cost-effective and would spare from CMV surveillance in 42% of patients with low risk for CS-CMV.

Basophil activation test as predictor of severity and threshold of allergic reactions to egg.

Identifying patients at risk of severe allergic reactions and/or low threshold of reactivity is very important, particularly for staple foods like egg. One hundred and fifty children underwent double-blind placebo-controlled food challenge (DBPCFC) to baked egg (BE), skin prick testing and blood collection for serology and basophil activation test (BAT). Patients who passed BE DBPCFC underwent loosely cooked egg (LCE) DBPCFC. Severity of allergic reactions was classified following Practall guidelines and threshold dose was determined during DBPCFC. Sixty out of 150 (40%) children reacted to BE and 16 out of 77 (21%) to LCE on DBPCFC. Considering DBPCFC to BE, 23 children (38%) had severe reactions and 33 (55%) reacted to 0.13 g or less of egg protein (low threshold group). Two children (2 out of 16 = 12%) had severe reactions to LCE. Demographic, clinical and most immunological features were not significantly different between severe/non-severe BE reactors or low/high threshold groups. Severe BE reactors had higher ovomucoid-sIgE (p = .009) and higher BAT to BE (p = .001). Patients with lower threshold to BE had higher IgE-specific activity (p = .027) and BAT to egg (p = .007) but lower severity score (p = .008). Optimal cut-offs for ovomucoid-sIgE had 100% sensitivity, 35% specificity and 60% accuracy and for BAT 76% sensitivity, 74% specificity and 75% accuracy to identify BE severe reactors. Optimal cut-offs for specific activity had 70% sensitivity, 68% specificity and 69% accuracy and for BAT 70% sensitivity, 72% specificity and 71% accuracy to identify low threshold patients. BAT was the best biomarker to predict severity and threshold of allergic reactions to BE and can be useful when making decisions about management of egg allergy.

Extrinsic and Intrinsic Modulators of Anaphylaxis.

The severity of anaphylaxis is determined by many factors. The allergenic source as well as the age of the affected individual and the route of allergen exposure encompass the major contributors of the clinical outcome. Moreover, the severity can be modulated further by intrinsic and extrinsic factors. Among these, the genetic predisposition, certain comorbidities such as uncontrolled asthma, and hormonal fluctuations have been proposed as intrinsic and antihypertensive medications or physical activity as extrinsic factors. Recent advances have highlighted immunologic pathways that may exacerbate the response to allergens through receptors on mast cells, basophils, platelets, and other granulocytes. Atopy, platelet-activating factor acetylhydrolase deficiency, hereditary alpha tryptasemia, and clonal mast cell disorders are examples associated with genetic alterations that may predispose to severe anaphylaxis. Identifying risk factors that lower the threshold of reactivity or increase the severity of multisystem reactions is important in the management of this patient population.

Clinical outcomes of efficacy in food allergen immunotherapy trials.

With food allergy affecting millions of children worldwide, the consolidation of food allergen immunotherapy represents an encouraging therapeutic option, that might expand in the next few years to reach greater number of candidates. This review aims at providing a critical overview of the efficacy outcomes employed in food allergen immunotherapy trials (AIT). Understanding efficacy endpoints rely on identifying what and how these are being measured. Desensitization, as the efficacy of the therapy to increase the patient's reactivity threshold to the food during therapy, and Sustained Unresponsiveness, withholding such efficacy even if the therapy is withdrawn, are nowadays considered the main parameters of efficacy evaluation. Quality of life is a promising variable to capture food AIT impact from the patient's perspective.There is a relevant degree of heterogeneity across studies in outcomes definitions and also in oral food challenges design, the tool that is more spread to assess results, hampering study comparison. Interpreting the results of a clinical trial, and comparing data from different studies is an important task, both for the researcher and the clinician, that should be done after a careful analysis of the outcomes and the evaluation tools used.

IgE-immunoadsorption for severe allergy to multiple foods: A case series of five children

BackgroundChildren with severe food allergy may present high risk of fatal anaphylaxis and a highly impaired quality of life. Anti IgE-treatment has been shown to be a promising approach as monotherapy for severe allergy to multiple foods. However, very high serum total IgE levels may limit its use.This study aims to assess the efficacy of IgE-selective immunoadsorption (IgE-IA) on total IgE levels and threshold of reactivity to the culprit foods in children with history of severe anaphylaxis due to multiple foods and allergic comorbidities. MethodsIn this single-center, prospective, open-label efficacy study we evaluated children with severe asthma, allergy to 2+foods and total IgE levels >2300 kUI/L. To establish the food reactivity threshold, each patient underwent oral food challenges (OFCs) before and after IgE-IA. ResultsFive patients (4 males; age, 12.2 ± 5 years, mean ± SD) underwent an average of 3 (range 2–4) sessions of IgE-IA. Each session reduced IgE levels by a mean of 1958.87 kUI/L. After the IgE-IA cycle, serum total IgE dropped from 3948 ± 1652.7 (mean ± SD) to 360.8 ± 71.9 kUI/L (−10.9 folds; p = 0.01). The threshold of reactivity (No Observed Adverse Effect Level, NOAEL) tested at OFCs for the culprit foods (4 baked-milk + 2 baked-egg + 1 lentil + 2 hazelnut + 1 wheat) increased overall from 21.5 (median, IQR 1.5–82.6) protein milligrams to 1115 (837.2–4222.8) milligrams (p < 0.001), ie, up to 51.8 times higher than baseline. 8/10 OFCs were negative after IgE-IA. ConclusionsIgE-IA increased food threshold quickly. It can be considered in well-selected patients with severe food allergies and high IgE-levels especially if otherwise eligible to anti IgE treatment.

A globally accurate potential energy surface and quantum dynamics calculations on the Be(1S) + H2(v0 = 0, j0 = 0) → BeH + H reaction

The reactive collision between Be atom and H2 molecule has received great interest both experimentally and theoretically due to its significant role in hydrogen storage, astrophysics, quantum chemistry and other fields, but the corresponding dynamics calculations have not been reported. Herein, a globally accurate ground-state BeH2 PES is represented using the neural network strategy based on 12371 high-level ab initio points. On this newly constructed PES, the quantum time-dependent wave packet calculations on the Be(1S) + H2(v0 = 0, j0 = 0) → BeH + H reaction are performed to study the microscopic dynamics mechanisms. The calculated results indicate that this reaction follows the complex-forming mechanism near the reactive threshold, whereas a direct H-abstraction process gradually plays the dominant role when the collision energy is large enough. The newly constructed PES can be used for further dynamics calculations on the BeH2 reactive system, such as the rovibrational excitations and isotopic substitutions of the H2 molecule, and the presented dynamics data would be of importance in experimental research at a finer level.

Cow's milk and egg protein threshold dose distributions in children tolerant to beef, baked milk, and baked egg.

The use of eliciting doses (EDs) for food allergens is necessary to inform individual dietary advice and food allergen risk-management. The Eliciting Dose 01 (ED01) for milk and egg, calculated from populations of allergic subjects undergoing oral food challenges (OFCs), are 0.2mg total protein. The respective Eliciting Dose 05 (ED05) is 2.4mg for milk and 2.3mg for egg. As about 70% children allergic to such foods may tolerate them when baked, we sought to verify the EDs of that subpopulation of milk and egg-allergic children. We retrospectively assessed consecutive OFC for fresh milk and egg between January 2018 and December 2020 in a population of baked food-tolerant children. Among 288 children (median age 56 - IQR 36-92.5months, 67.1% male) included, 87 (30.2%) returned positive OFC results, 38 with milk and 49 with egg. The most conservative ED01 was 0.3mg total protein (IQR 0.03-2.9) for milk and 14.4mg total protein (IQR 3.6-56.9) for egg. The respective ED05 was 4.2 (IQR 0.9-19.6) mg for milk and 87.7 (IQR 43-179) mg for egg. Such thresholds are, respectively, 1.5 (milk ED01), 1.75 (milk ED05), 72 (egg ED01), and 38.35 (egg ED05) times higher than the currently used thresholds. The subpopulation of children allergic to milk and egg, but tolerant to baked proteins, displays higher reactivity thresholds than the general population of children allergic to milk and egg. Their risk stratification, in both individual and population terms, should consider this difference. In baked milk-tolerant children, milk causes reactions at lower doses than egg in our group of egg-tolerant children. This could be associated with the relative harmlessness of egg compared with milk in the determinism of fatal anaphylactic reactions in children.

Advancing Base Metal Catalysis through Data Science: Insight and Predictive Models for Ni-Catalyzed Borylation through Supervised Machine Learning

An expansive data set containing 33 substrates, 36 unique monophosphine ligands, and two solvents was produced for the NiCl2·6H2O catalyzed aryl (pseudo)halide borylation with tetrahydroxydiboron for a total of 1632 reactions. Exploratory data analysis revealed excellent reaction performance with simple triarylphosphines (P(p-F-Ph)3 and P(p-Anis)3) and mixed aryl-alkyl phosphines (PPh2Cy), in addition to the previously established high performance with Cy-JohnPhos. The data were used to train machine learning models that predicted out of sample reaction performance with a root-mean-square error of 18.4. The important features extracted from the models identified three phosphine parameters that offered reliable reactivity thresholds for identifying optimal ligand performance. The predictive models showed reasonable performance for predicting reaction yields employing ligands not included in model training, while the important feature boundaries accurately classified the performance of 10 of the 12 external ligands examined.

Report of RILEM TC 267-TRM phase 3: validation of the R3 reactivity test across a wide range of materials

RILEM TC 267 TRM– “Tests for Reactivity of Supplementary Cementitious Materials” recommends the Rapid Reliable Relevant (R3) test as a method for determining the chemical reactivity of supplementary cementitious materials (SCMs) in Portland cement blends. In this paper, the R3 test was applied to 52 materials from a wide range of conventional and alternative SCMs with the aim to validate such test. An excellent correlation was found between the cumulative heat release and the bound water determined following the R3 test method. Comparison of the R3 test results to mortar compressive strength development showed that all conventional SCMs (e.g. blast furnace slag and fly ashes) followed the same trend, with the notable exception of very reactive calcined kaolinitic clays. It is discussed, through an in-depth statistical regression analysis of the R3 reactivity test results and the 28 days relative compressive strengths, how reactivity threshold values for classification of the chemical reactivity of SCMs could be proposed based on the R3 test results.

Blunted cardiovascular reactivity to psychological stress and prospective health: a systematic review

ABSTRACT Novel research demonstrates that lower or ‘blunted’ cardiovascular reactions to stress are associated with a range of adverse outcomes. The aim of the current review was (1) to examine the prospective outcomes predicted by blunted cardiovascular reactivity and (2) to identify a range of blunted cardiovascular reaction levels that predict these outcomes. Electronic databases were systematically searched (Medline, PsycArticles, PsycInfo, CINAHL, PubMed, Web of Science). Studies were included if they examined the prospective influence of blunted cardiovascular reactivity to psychological stress (SBP, DBP or HR) on a negative health, behavioural or psychological outcome. A total of 23 studies were included in the review. Blunted reactivity predicted (1) adverse cardiovascular health, primarily in cardiac samples (e.g., myocardial infarction, carotid atherosclerosis) and (2) outcomes associated with motivational and behavioural dysregulation in healthy samples (e.g., obesity, smoking addiction, depression). The cardiovascular reactivity threshold levels that were predictive of adverse health outcomes ranged between −3.00–12.59 bpm (14.41% to 136.59% lower than the sample mean) and −2.4–5.00 mmhg (65.99% to 133.80% lower than sample mean), for HR and DBP respectively. We posit that blunted reactions lower than, or equal to, the ranges reported here may be utilised by clinicians and researchers to identify individuals who are at increased risk of adverse cardiovascular health outcomes, as well as outcomes associated with motivational and behavioural dysregulation.