The outcome of most therapies in medicine is uncertain. Research based on hypothesis testing with a dichotomous outcome is therefore not very useful in daily practice. An increased probability of recovery of the individual patient is often the best possible outcome. Attempts to prove that homeopathy is not placebo have shown to be unproductive, both in convincing the medical community because of an implausibility of biological action of high dilutions, and in improving homeopathy's effectiveness. Priority should instead be given to improving the homeopathic method itself. A large amount of long-standing knowledge must be confirmed, but confirmation bias must be avoided. Clinical practice requires probability statistics, Bayesian statistics, clinical judgment and handling of bias. Classification of statistical uncertainty based on cumulative binomial probability seems more appropriate than one cut-off value for statistical significance. Bias should be better understood in order to prevent and correct it. A large amount of clinical expertise is already available to improve our method. Uncertainty cannot be ruled out in clinical practice and requires probability statistics. Probability and clinical judgment are realities that cannot be ignored. The reduction of bias requires a paradigmatic shift towards critical appraisal of research outcome and searching for independent data that do not necessarily confirm our findings. Such data could reveal bias and help to explain and reduce it.
Treatment for heart failure with mildly reduced ejection fraction (HFmrEF) and preserved ejection fraction (HFpEF) has evolved significantly in recent years. This period of therapeutic progress follows a span of over two decades during which randomized controlled trials (RCTs) of neurohormonal blockade and other therapies failed to definitively demonstrate clinical benefits. As such, traditionally, management guidelines for HFmrEF and HFpEF were limited to recommendations focused on optimization of volume status with diuretics, management of comorbidities, and consideration of certain medications such as angiotensin receptor-neprilysin inhibitor (ARNi) or steroidal mineralocorticoid receptor antagonists (MRA) to subsets of patients. After definitive results from multiple RCTs, sodium-glucose cotransporter 2 inhibitors (SGLT2i) are currently a main pillar in treating HFmrEF and HFpEF in European and American guidelines. However, other therapies, including non-steroidal mineralocorticoid receptor antagonists (nsMRA) and glucagon-like peptide-1 receptor agonists (GLP-1 RA), are proving to be additional effective treatments for HFmrEF and HFpEF and preventing the progression of cardiovascular-kidney-metabolic (CKM) syndrome. There is now increasing justification for combining multiple proven treatments for HFmrEF and HFpEF to maximize potential benefits. Treatment for different types of heart failure has improved significantly in recent years. For many years, there were few treatments that clearly helped people with heart failure whose heart still pumps normally or nearly normally. Care mainly focused on treating symptoms, helping the body remove excess fluid, and managing related health conditions such as high blood pressure, diabetes, and obesity. Today, research has expanded the available treatment options. One important group of medicines helps the body remove excess sugar and salt through the urine, which also reduces excess fluid and lowers the strain on the heart. Newer studies have shown that medicines that block the effects of a hormone called mineralocorticoid can improve outcomes while causing fewer side effects than older steroid-based treatments. For people who also have obesity, another newer group of medicines that acts on natural gut hormones has been shown to improve symptoms, physical activity, and quality of life. Overall, using a combination of these newer treatments may help people with heart failure whose heart still pumps normally or nearly normally feel better, improve their quality of life, and achieve better long-term health outcomes.
A set of rubber oxygenases was discovered through phylogenetic analysis and AI-based structural modeling of complexes of the putative enzymes with a substrate mimicking cis-1,4-polyisoprene. Sixteen candidate proteins were selected from thermophilic microorganisms, all sequence-related to the Latex clearing protein from Streptomyces sp. K30 (LcpK30). Sequence truncation and solubility tags were then evaluated to enhance protein expression, with the SUMO tag proving to be the most effective. Including LcpK30, nine heme-containing oxygenases were successfully expressed in E. coli NEB 10-beta cells, purified (35-157 mg L-1 yield) and characterized. Steady-state kinetics revealed significant rubber latex-degrading properties for six of them, with the truncated SUMO-fused LcpK30 (SUMO-LcpK30T) showing activity in agreement with literature. Notably, the catalytic efficiencies of all the expressed homologs lay within one order of magnitude and the oxygenase from Thermomonospora echinospora was found to be particularly promising in terms of activity, especially at high latex concentrations (more than 1% w/v). The analysis of reaction mixtures by both HPLC and HPLC-MS confirmed the oxidation of cis-1,4-polyisoprene to form the expected isoprenoid oligomers (n = 2-12), whose distribution was consistent with the usual endo-type cleavage pattern in all but one case. This bioprospecting effort afforded a platform of new rubber-degrading enzymes with diverse efficiencies and product profiles, capable of adapting to targeted applications.
T-cell exhaustion marked by soluble PD-1 (sPD-1) and soluble TIM-3 (sTIM-3) has been implicated in systemic lupus erythematosus (SLE), yet the cytokine mechanisms driving checkpoint-receptor upregulation, the relationship with complement consumption, and the clinical utility of these markers remain incompletely characterised. In a case-control with cross-sectional study of 120 participants (40 active SLE, 40 quiescent SLE, 40 healthy controls), serum sPD-1, sTIM-3, IL-6, ferritin, complement proteins (C3, C4, C1q), anti-dsDNA, CRP, ESR, and urinary protein-to-creatinine ratio (UPCR) were measured. A 12-parameter Spearman correlation matrix, principal component analysis (PCA) of 10 standardised biomarkers, ROC curve analysis with bootstrap 95% CIs and DeLong pairwise comparisons, lupus-nephritis (LN) subgroup analysis, and four pre-specified novel analyses were performed: (i) formal bootstrap mediation analysis of the IL-6 → sPD-1/sTIM-3 → SLEDAI-2K pathway; (ii) the sTIM-3/sPD-1 imbalance ratio; (iii) an Exhaustion-to-Complement Index (ECI); and (iv) multivariable logistic regression for LN prediction. The SLE Immune Exhaustion Index (SIEI) was evaluated by ROC analysis. Four primary biomarkers were significantly elevated in active versus quiescent SLE and healthy controls (Kruskal-Wallis H 87.2-99.0; all p < 0.001), with strong positive correlations with SLEDAI-2K (rho = 0.647-0.747). PCA identified a single dominant axis (PC1 = 78.9% variance) driven by exhaustion and inflammatory markers opposing complement proteins. Individual ROC AUCs were: sPD-1 0.932, sTIM-3 0.966, IL-6 0.944, and ferritin 0.953; the SIEI achieved 0.974, significantly exceeding sPD-1 alone (p = 0.002) but not the other individual markers. Bootstrap mediation analysis confirmed that sPD-1 and sTIM-3 each mediated approximately one-third of the IL-6 effect on SLEDAI-2K (indirect effects 0.276 and 0.303; bootstrap 95% CI excluding zero; Sobel p < 0.001). The ECI correlated strongly with SLEDAI-2K (rho = 0.86, p < 0.001; within-cohort AUC = 0.985). The UPCR plus sPD-1 plus IL-6 model significantly improved LN prediction over UPCR alone (AUC 0.869 vs 0.699; bootstrap p = 0.020), with sPD-1 carrying the dominant predictive contribution. Serum sPD-1 and sTIM-3 are closely associated with the IL-6-related, complement-consuming inflammatory network of SLE, in a pattern consistent with but not proving a mechanistic link. The SIEI is the first named, weighted composite exhaustion score in SLE, with within-cohort discrimination that requires prospective external validation. These findings support T-cell exhaustion as a serologically accessible disease axis with direct implications for disease monitoring and lupus-nephritis risk stratification.
Motor imagery (MI) brain-computer interfaces (BCI) rely on precise electroencephalogram (EEG) classification. However, issues such as the reliance on extensive manual experience for MI-EEG model design, parameter tuning, and optimization directions, along with the poor task flexibility of foundation models and state degradation during long-term multi-agent iterations, severely restrict the state-of-the-art (SOTA) efficiency of MI-EEG. To address these challenges, we propose AutoMI, a novel framework that uses multi-agent automated rapid iterations to construct SOTA MI-EEG models. AutoMI introduces a hybrid decision mechanism that tightly couples Q-learning strategies with deterministic rules. By integrating planning, execution, and output agents with predefined tools, AutoMI ensures broad general applicability across various hyperparameter optimizations and structural improvements. Furthermore, AutoMI integrates experience tracking and rollback mechanisms to prevent ambiguous optimization. In evaluations on the IV2a, OpenBMI, and ECUST-MI datasets, the SOTA models finally constructed through AutoMI iterations achieve accuracies of 77.62%, 78.08%, and 83.02%, with maximum improvement reaching 24.69%, 23.35%, and 23.28% respectively. Furthermore, the average time per iteration for a single subject on the OpenBMI dataset is approximately 500 s. Compared with automated optimization algorithms, the accuracies increase by 18.42%, 9.27%, and 19.25% respectively, demonstrating the effectiveness of the proposed AutoMI framework and proving that its optimization capability reaches SOTA. Experimental results indicate that AutoMI provides a novel perspective and framework design reference for future BCI model optimization.
Viewing times (VTs) are established indirect measures of sexual interests. They are based on the effect that stimuli of sexually attractive target groups are scrutinized longer than stimuli of non-attractive groups in sexual attractiveness rating tasks. When assessing sexual interest in children and adults, decision latencies for target sexual maturity categories are typically compared by subtracting average latencies for children from average latencies of adults. In this study, several ways of improving the scoring algorithm were explored (e.g., using standardized differences, excluding the longest VTs of each category from the scoring, or conducting a profile analysis based on peaks in certain target categories). Scoring algorithms were compared in terms of reliability, convergent validity, and the influence of confounding variables in a secondary analysis of a German male community sample (N = 8554). Additionally, the influence of the scoring on the number of participants who would be classified as exhibiting (increased levels of) sexual interest in children was investigated. The VT task's validity proved to be quite robust to changes in scoring, but the reliability and classification proportions differed substantially between scores. The best performing score was the mean difference of adult and child target groups with the exclusion of the longest VT in each target category. The results imply that the scoring approach should be chosen based on the research or diagnostic goal of using the VT task (e.g., whether one prioritizes sensitivity or specificity). The study underlines the influence of measurement and scoring approach on prevalence estimates of (increased) sexual interest in children.
To validate a Bayesian method for sex estimation from permanent canines (Luna, 2019) on an independent contemporary skeletal sample from Argentina. The study analyzed 152 permanent canines (61 upper, 91 lower) from 98 individuals (55 males, 43 females) included in the Prof. Dr. Rómulo Lambre Reference Collection (La Plata, Argentina). Buccolingual and mesiodistal diameters of the crown and neck region were measured. Bayesian posterior probabilities were computed for single- and multi-variable models, and classification accuracy was assessed against documented biological sex. The buccolingual neck diameter was the best single predictor, yielding accuracy rates of 73.77% (lower canines, p = 0.74) and 73.62% (lower canines, p = 0.74). Multi-variable models improved performance: using only the neck diameter, lower canines achieved 81.96% accuracy (p = 0.78), and upper canines, 80.21% (p = 0.80). The four-variable model produced the highest overall accuracy (lower: 85.24%, p = 0.85; upper: 83.51%, p = 0.83). Sex-specific correct classification rates ranged 80.77-83.33% for females and 83.63-88.57% for males, with posterior probabilities of 0.78-0.88 and 0.80-0.86, respectively. Neck metrics demonstrate strong performance for sex estimation, proving particularly valuable for commingled or isolated remains. This Bayesian probabilistic framework provides transparent uncertainty estimates essential for forensic standards and can be successfully applied to contemporary non-identified individuals of similar geographical provenance.
In this work, we established a decarboxylative cascade process to achieve functionalized pyrazolones. This approach directly employs carboxylic acids as alkylating reagents. An inexpensive iron photocatalyst enables this process when irradiated by visible light. The reaction demonstrated a broad substrate scope, proving compatible with various carboxylic acids and N-acrylohydrazones. Furthermore, biological activity evaluation revealed that compound 3ak acted as a potent inhibitor of NO production, while compound 3al exhibited potent antiproliferative activity against the PANC-1 cell line, with an IC50 value of 14.3 μM.
A novel, green, and highly sensitive spectrofluorimetric approach for the determination of cabergoline (CG) is presented. The method relied on the strategic modulation of the photoinduced electron transfer (PET) process. The native fluorescence of CG is inherently decreased by its tertiary amine moiety. The addition of hydrochloric acid efficiently diminishes this PET pathway ("PET-off"), resulting in a considerable, acid-induced improvement of the intrinsic fluorescence signal at 330 nm (excitation at 280 nm). The suggested mechanism is verified by density functional theory (DFT) calculations, which show a reduced HOMO-LUMO energy gap upon protonation, and by time-resolved fluorescence measurements confirming a significant increase in fluorescence lifetime of the protonated CG. Furthermore, analysis of the electrostatic potential (ESP) maps offered visual evidence of the electronic redistribution upon protonation. Following systematic optimization, the method demonstrates excellent analytical performance for the standard CG quantification and spiked human plasma in the ranges of 25 - 500 and 40 - 400 ng/mL, respectively. The method was fully validated per ICH guidelines, showing high accuracy (recoveries: 98.50 - 100.51%) and precision (%RSD < 2.0%). The described method was successfully applied for the assay of CG in pharmaceutical tablets, with statistical comparison to a reference method, and to content uniformity testing per USP guidelines. The method also proved real feasibility for the determination of CG in spiked human plasma samples. A comprehensive green chemistry assessment using AGREE metric, BAGI metric, ComplexMoGAPI, as well as RGB model, supported the method's outstanding green environmental profile and sustainable practical applicability. This PET-based fluorimetric strategy offers a simple, rapid, eco-friendly, and cost-effective alternative for the routine analysis of CG in quality control and bioanalytical laboratories.
Venous malformations of the hand represent a clinical and therapeutic challenge due to anatomical complexity and functional and aesthetic impact. We report the case of a 13-year-old female patient with a venous malformation of the hand, treated with a combined approach using Nd:YAG 1064 nm transdermal laser and 1% polidocanol foam sclerotherapy. The combination of photocoagulation and sclerotherapy proved safe and effective in a superficial and localized lesion. This case underscores the relevance of combined therapy as a minimally invasive alternative for venous malformations of the hand, highlighting the importance of individualized treatment according to lesion location, depth, and extent. As malformações venosas da mão representam um desafio clínico e terapêutico devido à complexidade anatômica e ao impacto funcional e estético. Relatamos o caso de uma paciente de 13 anos de idade, sexo feminino, portadora de malformação venosa da mão, tratada com abordagem combinada de laser transdérmico Nd:YAG 1064 nm e escleroterapia com espuma de polidocanol a 1%. A associação entre fotocoagulação e escleroterapia mostrou-se eficaz e segura em lesão superficial e localizada. O presente relato reforça a relevância da terapêutica combinada como alternativa minimamente invasiva para malformações venosas da mão, destacando a importância da individualização do tratamento conforme a localização, profundidade e extensão da lesão.
In visual object tracking, one-stream trackers typically use all search tokens to interact with templates across all encoder layers. However, the search area usually contains a lot of interference information, such as distractors with similar appearance to the tracking object, which will cause the distractors in the search area to be misjudged as interactive objects, establish wrong cross-relation modeling, and reduce the accuracy of tracking. To alleviate this issue, this paper proposes a transformer-based visual object tracking framework with adaptive token division. First, our tracking framework is a simple encoder-decoder structure without any post-processing. Second, we propose an adaptive token division module, which enables search tokens and template tokens to perform the most appropriate cross-relationship modeling, and improves the model 's ability to distinguish between object and background. At the same time, we introduce an attention masking strategy and Gumbel-Softmax technique. The strategy enables efficient and parallel attention calculation between different categories of tokens, and the technique facilitates the end-to-end optimization of the division module. Finally, we conduct tests on six tracking benchmarks, and the experimental results prove the effectiveness of our method.
High-dimensional incomplete data often suffers from severe outlier interference and rigid loss constraints, which significantly limit the performance of collaborative filtering. Although multi-metric autoencoders improve representation learning by fusing multiple metrics, their static loss functions fail to dynamically balance robustness and generalization. To address this issue, we propose Cauchy-MMA, a novel framework that integrates multi-metric autoencoders with adaptive Cauchy loss. The core innovations include: (1) exploiting the outlier-resistant property of the Cauchy distribution to construct a robust loss that suppresses gradient explosion caused by outliers; (2) designing a continuous and fully differentiable parameter adaptation mechanism to dynamically adjust penalties according to error magnitudes; and (3) adaptively integrating two adaptive Cauchy loss variants with four static losses to form a six-branch collaborative learning system. Theoretical analysis establishes sublinear regret bounds for the ensemble aggregation, proves asymptotic convergence of suboptimal model weights, and derives a strict boundedness guarantee for the adaptive loss influence function. Extensive experiments on four real-world datasets demonstrate that Cauchy-MMA achieves highly competitive performance against recent graph-based and robust baselines across rating prediction and Top-K recommendation tasks, and substantially mitigates performance deterioration under strong outlier interference.
From 2020 to 2022, an outbreak of listeriosis occurred in Austria, resulting in ten cases, three of which proved fatal. The outbreak was traced to a traditional southern European dairy product known as Kajmak, a lightly salted cream product. The subsequent sequencing of clinical and food-related isolates with clonal complex (CC)1 clonal type (CT) 6568 led to the identification of the outbreak's origin. CT6568 is classified under CC1, which exhibits notable diversification among human isolates, with 14 distinct CTs identified between 2020 and 2022. The clientele of the cheese factory primarily comprised local Balkan restaurants, delicatessen counters, and small bakeries. The existing self-monitoring system and the Hazard Analysis and Critical Control Points (HACCP) program did not meet the requisite standard of adequacy. Listeria monocytogenes was identified in the production and ripening room, indicating potential recontamination of Kajmak during the manual filling and ripening process. The highly perishable product in question was also incorrectly labeled with a best-before date (>21 days) instead of a use-by date. Furthermore, crucial labeling information for customers, such as the necessity of strict refrigeration at 4 °C, was absent. The outbreak was likely precipitated by the discontinuous production of Kajmak, which resulted in inadequate environmental hygiene. The retrospective report on the outbreak highlights the lack of risk analysis in research conducted on food safety risks associated with small-scale production of traditional foods. It is essential that manufacturers align their understanding with the principles of the HACCP concept and effective self-monitoring systems.
Partners in Contraceptive Choice and Knowledge (PICCK) was a time-limited (2018-2023) initiative to improve access to and quality of contraceptive care at Massachusetts birth hospitals and included continuous involvement of a community advisory board (CAB). In addition to providing strategic guidance, CAB members co-lead didactic activities, helped develop a patient-centered contraceptive decision aid, and created a novel mechanism to provide health literacy and accessibility assessments to clinics. Inclusion of a CAB in PICCK proved feasible and helped ensure equity-focused programming.
Tuberculosis (TB) continues to demand new chemotypes able to overcome acquired drug-resistance. Here, we designed and synthesized two related series of twenty 3,5-dinitrophenyl-based 1,2-diacylhydrazines and their cyclic analogues, 2,5-disubstituted 1,3,4-oxadiazoles, using 1,2-diacylhydrazine formation followed by cyclodehydration to the oxadiazole core. This approach proved decisive, as the oxadiazoles displayed a broader and markedly stronger antimycobacterial profile than their precursors. The synthesized derivatives inhibited drug-susceptible Mycobacterium tuberculosis H37Rv from 0.125 μM, retained potent activity against drug-resistant TB isolates (0.125-1 μM), and remained active against non-tuberculous mycobacteria (M. kansasii, M. avium), with 2-(3,5-dinitrophenyl)-5-(quinolin-6-yl)-1,3,4-oxadiazole 4t emerging as the most balanced lead across all strains tested. In addition to their anti-TB activity, selected oxadiazoles also displayed complementary antibacterial effects, particularly against Gram-positive bacteria including MRSA and Staphylococcus epidermidis (MIC values from 31.25 μM), whereas antifungal activity was generally limited. Importantly, the most active compounds combined high antimycobacterial potency with low cytotoxicity, and haemolytic activity was also low. Taken together, these data identify 3,5-dinitrophenyl-substituted 1,3,4-oxadiazoles as a synthetically accessible and highly promising platform for further development of selective anti-TB agents.
Patients with patellofemoral instability (PFI) often demonstrate altered movement patterns and strength deficits. The vastus medialis plays an important role in patellar stabilization as a dynamic medial force vector on the patella. It was hypothesized that limb-to-limb asymmetries in muscle activity would be present preoperatively and at the time of return to sport (RTS). Cross-sectional study; Level of evidence, 3. A total of 25 adolescents with unilaterally treated PFI were evaluated before arthroscopic assisted medial patellofemoral ligament reconstruction with an allograft. A separate group of 16 patients with PFI were examined for RTS clearance. All participants completed an unweighted squat task in a motion capture laboratory. Surface electromyography sensors were placed on the rectus femoris, vastus medialis, semitendinosus, tibialis anterior, and gastrocnemius. Electromyography data were filtered and rectified, and a linear envelope was created. Peak activity of each muscle was analyzed. The Wilcoxon signed-rank test was used to compare muscle activity between limbs (α = 0.05). Preoperatively, peak rectus femoris activity of the involved limb was 40% less than that of the contralateral limb (P = .006). At the time of RTS, peak vastus medialis activity was 73% less in the involved limb than in the contralateral limb (P = .001). A preoperative reduction in rectus femoris activity of the involved limb indicated that there might be compensations in movement patterns among those with PFI. At the time of RTS after medial patellofemoral ligament reconstruction, vastus medialis discrepancies suggested that there might be a muscle imbalance after surgery and continue through physical therapy. A greater emphasis on vastus medialis training may prove beneficial during the rehabilitation process and help to prevent the reduction in activity observed at the time of RTS.
Atrazine, a synthetic herbicide from the triazine family, is found to be the most harmful and commonly detected organic pollutant in surface and groundwater. Therefore, there is an increasing demand for sensing platforms that are portable, economical, and capable of rapid detection of trace amounts of atrazine in environmental matrices. So, the present work deals with the facile electrospinning of pure carbon dots (CDs), N-doped CDs (NCDs) and Ag-functionalized CDs (ACDs) embedded in polyvinyl pyrrolidone (PVP)-based electrospun mats (EM), designed for efficient fluorescence-based detection of atrazine in water/aqueous environments. The photophysical (UV-visible and fluorescence spectroscopy), microstructural (XRD, FTIR), morphological (SEM, HRTEM), and thermal (TGA) analysis of the synthesized CDs, as well as the fabricated EM, were thoroughly evaluated. To further understand the sensing performance, interference (in the presence of different analytes) and titration study (at various concentration levels) were performed, which suggested the selective and sensitive behavior of CDs towards atrazine in a concentration-dependent manner. A strong fluorescence-based detection behavior of synthesized CDs was observed with emission peaks centered around ∼440-460 nm. The Stern-Volmer plot suggested the values of detection ∼0.079, ∼ 0.081, and 0.125 μM and reflects that the fabricated system can sense atrazine up to a very low level (∼ 0.017- ∼ 0.0269 μg/mL) for PV-CDs, PV-NCDs and PV-ACDs. To prove the effectiveness of the prepared system, real sample analysis was carried out using different environmental water samples, which suggested ∼ >96% recovery/detection of atrazine. The development of such a nanofibrous atrazine sensing framework may pave the way for a model substitute from the conventionally available approaches to a highly sustainable, environmentally friendly and engineered CDs-based platform for real-time monitoring of triazine-based and/or other similar contaminants in water.
Keloid is a pathologic scar formation resulting from trauma, burns, surgery, or unknown causes, leading to deformity and varying degrees of functional impairment, significantly impacting the physical and mental well-being as well as the quality of life of affected individuals. Studies have indicated that Mesenchymal Stem Cells (MSCs) can effectively promote wound healing in various injuries, reducing the formation of keloid. This study aims to explore an in vitro model of keloid and investigates the effects of exosomes from human Umbilical Cord MSCs (HUCMSC) on fibroblast proliferation and apoptosis in keloid model. Methods include isolating primary fibroblasts, extracting HUCMSC exosomes (HUCMSC-Exos), and establishing a histamine-induced keloid model in vitro. Results show dose-dependent inhibition of keloid fibroblast activity by HUCMSC-Exos, affecting proliferation, apoptosis, and cell cycle. Through gene sequencing analysis, we investigated the abnormal gene expression and signaling pathway changes of histamine-induced keloid fibroblast before and after co-cultivation with HUCMSC-Exos. It turns out that HUCMSCs-Exos effectively inhibit the proliferation of keloid fibroblasts, promoting apoptosis and exhibiting a dose-dependent effect. We also proved that HUCMSCs-Exos regulated genes and inhibit signaling pathway by upregulating the expression of intracellular genes, ultimately inhibiting keloid fibroblasts proliferation activity and enhancing apoptosis. The research found that HUCMSC-Exos as potential regulators of keloid fibroblast behavior, offering insights for keloid treatment strategies.
The atmospheric corrosion threatens the structural reliability and service life of a wide range of engineering systems, which can cause economically significant degradation phenomena affecting metallic materials in industrial environments. Therefore, a New 2-((1H-indazol-5-yl) diazenyl)-1-phenylbutane-1,3-dione ligand (L) and its divalent cobalt, nickel, and copper complexes were synthesized and characterized. By using Elemental Analysis (CHN), Inductively Coupled Plasma (ICP), Molar Conductance (Λm), X-ray Powder Diffraction (XRD), Thermogravimetric analysis (TGA), and magnetic moment measurements. Also, Fourier Transform Infrared (FT-IR), Proton Nuclear Magnetic Resonance (1H-NMR), Carbon Nuclear Magnetic Resonance (13C-NMR), mass, and Ultraviolet-Visible (UV-Vis) spectroscopy. Through the nitrogen atom of the azo group and one oxygen atom of the carbonyl group, the ligand performs the function of a bidentate ligand. From the characterization and theoretical results, it was found that Co(II) and Ni(II) have an octahedral geometry, whereas the Cu(II) complex has a tetrahedral structure. The activity of ligand and its metal complexes as inhibitors to reduce the rate or prevent atmospheric corrosion of iron was investigated. Materials Studio 2017 software was used to study the adsorption on the Fe(110) surface. The computed adsorption energies follow the trend Cu(II) complex > Ni(II) complex > L > Co(II) complex, which is qualitatively consistent with the experimentally observed inhibition efficiency order. Scanning Electron Microscope (SEM) analysis proved that the specimen covered with Cu(II) complex has a good inhibitory effect that slows down the rate of corrosion compared with the blank and untreated specimen.
In the pinwheel scheduling problem, each task i is associated with a positive integer ai called its period, and we want to (perpetually) schedule one task per day so that each task i is performed at least once every ai days. An obvious necessary condition for schedulability is that the density, defined as the sum of execution rates 1/ai, does not exceed 1. We prove that all instances with density not exceeding 5/6 are schedulable, as was conjectured by Chan and Chin in 1993. Like some of the known partial progress toward the conjecture, our proof involves computer search for schedules for a large but finite set of instances. A key idea in our reduction to these finite cases is to generalize the problem to fractional (noninteger) periods in an appropriate way. As byproducts of our ideas, we obtain a simple proof that every instance with two distinct periods and density at most 1 is schedulable, as well as a fast algorithm for the bamboo garden trimming problem with approximation ratio 4/3.