Early-age rheology of cement paste evolves continuously with time due to hydration, directly affecting handling and placement; however, the combined roles of crucial influential parameters are not yet fully understood under practical conditions. This study investigates the effect of temperature, shear rate, and w/c on the temporal rheological behavior of cement paste. Rheological tests were conducted at 15 degrees C, 25 degrees C, 35 degrees C, and 45 degrees C for pastes using different w/c under controlled shear. To relate stress evolution to hydration, paste samples were hydration-arrested at 15, 30, and 60 min and analyzed using XRD and SEM. Results show that higher temperatures accelerate hydrate formation and stress development, but the resulting hydrate networks are unstable under sustained shear. At lower temperatures, structural development remains limited despite lower w/c. The findings show that early-age rheology is influenced by hydration progress and stability of hydrate networks, supporting practical rheological windows for conventional and advanced construction processes.

Early-age cement paste exhibits continuous changes in rheological behavior due to the combined effects of shear, hydration, and time. Conventional rheological tests often include rest periods or stepped shear changes, which can promote thixotropic rebuilding and hide hydration-driven effects. The purpose of this study is to develop a controlled shear-cycling protocol to limit rest-induced structural recovery and maintain a comparable shear history during early-age testing. Cement pastes with w/c of 0.40, 0.45, 0.50, and 0.55 were tested over the first 30 min after mixing using repeated high-shear disruption to maintain a controlled and comparable structural state, followed by short low-shear measurement intervals. Shear stress was observed as a function of shear rate, w/c, and elapsed time under conditions where the paste structure was repeatedly disrupted. A normalized stress index (NSI) was introduced to quantify short-time stress changes during the low-shear phase. Despite suppression of structural rebuilding, shear stress increased progressively for all mixtures, indicating an irreversible contribution from hydration. Most NSI values remained near zero or became negative, confirming that thixotropic recovery did not control stress evolution. Rheological trends are further supported by microstructural observations. A time-regime-based modeling framework was developed without assuming constant rheological parameters. These results are significant to practical processes, including mixing, pumping, placement, and extrusion, where early-age flow control is critical.

The cement industry is a major source of global CO2​ emissions, highlighting the need for sustainable alternatives that balance performance with reduced environmental impact. Geopolymers offer a promising low-carbon substitute to OPC, with reported emission reductions of up to 80%. Simultaneously, dimensional stone processing in India generates over 30 million tons of waste annually, causing serious air, water, and land pollution. Valorizing this waste in geopolymer binders provides dual benefits of waste mitigation and sustainable material development. The present study explores the use of dimensional stone waste with GGBS for geopolymer mortar production, focusing on optimizing strength and physical properties through mix design variables such as activator molarity and NaOH:Na2​SiO3​ ratios. Characterization of materials was conducted using XRF, XRD, and SEM. Results showed maximum compressive strength at 8 M NaOH with a 1:2.5 NaOH:Na2​SiO3​ ratio, along with higher density, and lower porosity and water absorption. The novelty lies in systematic optimization of activator parameters for stone waste-based geopolymers, which have not been studied in detail previously. Findings confirm the feasibility of converting challenging waste into high-performance binders, supporting circular economy goals. Beyond structural performance, the natural colour of stone waste enhances the aesthetic appeal of geopolymer products without synthetic pigments.

Limestone and coal scarcity demands alternative cement materials, yet agricultural-residues remain underexplored for dual-purpose as biofuel -> limestone/SCM. This study investigates de-oiled seed cakes (DSCs) from sesame and sunflower as biofuels and their combustion residues, de-oiled seed ashes (DSAs), as cementitious materials. DSCs exhibited calorific values of 4740-5217 kcal/kg and 20.85%-21.80% of ash, confirming biofuel suitability. XRF revealed CaO contents of 60.60% in DSA-S and 17.37% in DSA-SF, with SiO2 (6.53%) and Al2O3 (2.99%) in DSA-SF. XRD and FTIR confirmed calcite in DSA-S, while kalsilite and SiO2 were detected in DSA-SF. TGA demonstrated thermal stability with decomposition at 955 degrees C and 1163 degrees C. Physical properties including consistency, setting time, fineness, specific gravity, and soundness were satisfactory. DSA-SF contains high K2O (30.78%), requiring ASR mitigation consideration. Pozzolanicity was assessed through Frattini and Strength activity index tests. DSAs achieved compressive strength exceeding 80% of control at 20% OPC replacement, demonstrating dual-purpose potential supporting circular resource utilization.

Microwave-assisted synthetic methodologies have emerged as efficient, rapid, and sustainable strategies for the synthesis of structurally diverse heterocyclic compounds with significant anticancer potential. This review systematically highlights recent advances in the microwave-mediated synthesis of biologically active heterocycles, emphasizing accelerated reaction rates, improved yields, shortened processing times, and alignment with green chemistry principles. A critical evaluation of structure-activity relationships (SAR) along with synthesis is presented, illustrating how specific structural modifications influence anticancer potency and selectivity. By consolidating microwave-assisted synthetic approaches with anticancer activity, this work offers a novel perspective on the correlation between rapid synthesis and enhanced bioactivity. To the best of our knowledge, it is the first review to specifically focus on microwave irradiation in heterocyclic synthesis for anticancer applications, providing a valuable resource for the rational design of potent, biologically active, and environmentally sustainable heterocyclic scaffolds for next-generation anticancer therapeutics.

Herein, we disclosed a metal-free, highly efficient, and sustainable N-heterocyclic carbene-based organocatalyst utilized for the regioselective synthesis of mono- (4a-o) and bis-substituted benzimidazole (3a-s) derivatives under the optimized reaction conditions. The new catalytic protocol demonstrated high efficiency across a broad spectrum of substituted o-phenylenediamines (1a-f) and substituted benzyl alcohols (2a-k), and showed excellent tolerance towards various functional groups. The operationally developed protocol is quite simple, utilizes NHC as an organocatalyst, and furnishes the desired mono- (4a-o) and bis-substituted benzimidazole (3a-s) derivatives in up to 77% and 87% yields, respectively. While using NHC as an organocatalyst (catalyst C), bis-substituted benzimidazoles were obtained in the presence of a strong base (KOtBu), whereas mono-substituted benzimidazole was afforded using a weaker base (Cs2CO3). To gain deeper insight into the underlying mechanistic pathway, an array of control experiments has been performed. The mechanistic pathway involves in situ formation of aldehyde from the dehydrogenation of alcohol with the aid of NHC. Then, the resulting aldehyde condenses with diamine to generate imine, which, on further assistance with NHC, forms aza-Breslow intermediate, is converted into imidoyl azolium in aerobic conditions that subsequently undergoes cyclization to furnish benzimidazole. The mechanistic studies involved the detection of BHT-trapped ketyl adduct. Furthermore, EPR experiments suggested the possible involvement of free-radical species. Further, the synthetic utility of this protocol was demonstrated by gram-scale synthesis, intermolecular cyclization to 2-phenylquinazoline, and the synthesis of fungicide fuberidazole.

The article presents an innovative approach to understanding cement paste rheology for advanced construction applications, particularly three-dimensional (3D) concrete printing. Through a systematic investigation combining experimental observations with predictive modeling, the present article examines the complex relationship between reversible thixotropic behavior and irreversible hydration-induced changes in cement paste. Our novel methodology integrates distinct and constant shear rate testing protocols, providing comprehensive insights into rheological changes. By analyzing cement pastes with water-cement ratios of 0.40-0.55 and employing advanced characterization techniques, including isothermal calorimetry, x-ray diffraction, and scanning electron microscopy, critical correlations between microstructural development and rheological performance during early hydration were established. Key findings revealed optimal performance at water-cement ratios of 0.40-0.45, with maximum structural evolution at very low shear rates (0.01 s-1), showing differential values of 1,200-2,000 Pa. A comprehensive rheological model was developed and validated, achieving exceptional accuracy with R2 values of 0.92-0.98 and RMSE values below 15%. This research bridges materials science and practical construction applications, providing crucial insights for emerging technologies such as 3D concrete printing.

Bioheterocycles represent a pharmaceutically privileged class of compounds due to their broad spectrum of medicinal applications. Among them, indazole (benzopyrazole or isoindazole) is a fused nitrogen-containing heterocycle with significant importance in pharmaceuticals, bioactive molecules, and natural products. The indazole system exists in tautomeric forms 1H-, 2H-, and 3H-indazole, with 1H-indazole being the most prevalent and stable. Conventionally, indazoles are synthesized via the reaction of aromatic aldehydes or ketones with substituted phenylhydrazines. Naturally occurring alkaloids such as nigellicine, nigeglanine, and nigellidine feature the indazole nucleus as their core structure. Owing to its versatile biological profile, the indazole scaffold exhibits diverse pharmacological activities, including antibacterial, anticancer, anti-inflammatory, and neuroprotective effects. Moreover, it constitutes the structural backbone of several clinically relevant drugs such as Asitinib, Bozitinib, and Entrectinib. These attributes underscore the prominence of indazole as a key framework in contemporary medicinal chemistry and drug discovery. Overall, the article aims to provide a comprehensive understanding of how innovative C-H functionalization strategies have accelerated the design and development of bioactive indazole derivatives for pharmaceutical applications.

Rheology, or flow behavior, plays a vital role during fresh-state applications of cement composites. Understanding and controlling cement rheology are gaining significant attention for emerging construction practices like 3D printing. Literature defines cement rheology using one of the four mathematical models, i.e., Bingham, modified Bingham, Herschel–Bulkley, and Power law. The models defined in the literature are based on the shear stress and shear rate relationship and fail to account for temporal changes, like cement hydration. Cement hydration results in internal structural buildup with time, typically increasing the shear resistance. This effect is opposed by the breakdown caused by the applied shear rate. The combined effect of buildup and breakdown depends on cement hydration, time of observation, and applied shear rate. Existing models fail to explain the overall cement rheology across a long time span and a wide range of shear rates. As a result, literature often explains cement rheology using contradictory phenomena like thixotropy–rheopexy. The present study overcomes this challenge by presenting a novel mathematical model for cement rheology, which can account for the temporal effect of buildup and breakdown. The mathematical model is developed from an extensive experimental investigation of cement rheology across a wide range of shear rates and long time spans. For the first time, the mathematical model simultaneously explains buildup and breakdown mechanisms. The novel mathematical model includes temporal effects and can serve as the foundation for reimaging cement rheology for emerging construction practices.

Herein, a microwave-assisted, highly efficient, catalyst-free, green synthesis of a new cytotoxic synthon of prototype 2-substituted 5H-imidazo[2,1-b][1,3]thiazin-5-ones using easily accessible starting materials, is reported. The reaction time was reduced from 10 h (similar skeleton) to merely 10 min under microwave irradiation conditions, in up to 80% yield. The developed protocol provides a library of substituted 5H-imidazo[2,1-b][1,3]thiazin-5-one congeners with a broad substrate scope and functional group tolerance. Further, being a highly conjugated system, the photophysical studies (20a-e, 20g, 20j, 20l-m, 20q, 20v, and 20x) exhibited moderate fluorescent photophysical properties, and compound 20b was observed to show the highest value of the fluorescence quantum yield (Phi F = 23%). Furthermore, the cytotoxic activity assay of all synthesized compounds using the MTT assay against HeLa and A549 cancer cell lines provided compound 20h and 20i to be the best cytotoxic activity among the series, exhibiting more cytotoxicity as compared to the standard reference drug, Doxorubicin. In silico molecular docking, MD simulation studies, ADME prediction, and DFT analysis also confirm the probability of molecule 20h to function as an anticancer agent. To the best of our knowledge, this is the first report of microwave-assisted synthesis of the 5H-imidazo[2,1-b][1,3]thiazin-5-ones class of heterocycles showing potent cytotoxic activity.

Cross dehydrogenative coupling (CDC) via C−H bond activation enables direct and sustainable synthesis of carbon–carbon and carbon–heteroatom bonds, bypassing the requirement of prefunctionalization steps. Utilizing earth-abundant metals such as iron (Fe), cobalt (Co), nickel (Ni), and copper (Cu), CDC offers cost-effective, environmentally friendly alternatives to precious metal catalysts (Ru, Rh, Pd, Ir). These metals facilitate mild and efficient C–H activation, expanding substrate scope and improving selectivity. Among different methods, transition metal-catalyzed C−H activation via CDC has emerged as an effective tool for direct functionalization, offering efficiency, sustainability, and regioselectivity. Recent advancements address challenges such as catalyst deactivation and functional group compatibility. This article highlights recent developments of various synthetic alkylation, alkenylation, and alkynylation strategies of arenes and their mechanistic pathways catalyzed by earth-abundant metals (Fe, Co, Ni, and Cu) through cross dehydrogenative coupling via C−H bond activation.

In cold climates, pavement deterioration is significantly influenced by the dynamic duo of freeze-thaw cycles and fatigue loading, compounded by cyclic environmental stresses. This study examines their combined effects on concrete pavement degradation, focusing on microstructural changes and durability. Mechanical properties, including compressive strength, ultrasonic pulse velocity, porosity, and mass loss, were analyzed, alongside SEM and EDS evaluations. Results reveal that the dynamic duo causes more severe damage than individual or combined loading. Fatigue loading generates microcracks, while cyclic freeze-thaw stresses degrade the interfacial transition zone (ITZ), increasing porosity and reducing compressive strength up to 30 %. Elemental analysis shows an elevated calcium-silicon (Ca/Si) ratio, indicating microstructural weakening. Coupling actions reduce fatigue life by up to 75 %, and ultrasonic velocity tests show a 5 % reduction, highlighting intensified internal damage. Porosity and mass change increase significantly with repeated fatigue and coupling actions. Unlike previous studies that typically treat fatigue and freeze-thaw stresses in isolation or through sequential testing, this research introduces a novel coupled experimental approach to simulate the real-time interaction of mechanical and environmental loads. These findings mandate an urgent paradigm shift in cold-region pavement design: current practices significantly underestimate coupled damage effects, necessitating new interaction-based durability models and revised safety factors for realistic performance prediction under concurrent mechanicalenvironmental loading.

Globally, about one-third of food production ends up as waste and is responsible for about 8 α , and was used for the preparation of bacterial solution. The bacterial solution prepared with food waste was used along with waste tyre rubber fibres for the development of different bacterial mortars. Bacterial mortars were experimentally compared with non-bacterial mortars. Bacterial mortar prepared with food waste shows improved microstructure, doubles the compressive strength (increase by 105.94

This study seeks to enhance sustainable concrete by improving the performance of recycled coarse aggregates (RCA), with a particular focus on overcoming the challenges posed by aged cement mortar on the aggregate surfaces. A novel dual treatment method, combining chemical and abrasion techniques, is employed to improve the strength and durability of surface-modified recycled coarse aggregates (SMRCA). The process begins with hydrochloric acid treatment to weaken the mortar adhesion, followed by abrasion to remove the weakened mortar. This approach minimizes strength loss and strengthens the bond between the aggregate and the concrete matrix. Comprehensive analyses, including X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) spectroscopy, alongside tests for compressive strength, drying shrinkage, electrical resistivity, and chloride ion penetration, reveal significant improvements. Notably, a 32.64% increase in strength is observed at a 25% replacement (SMRCA 25), demonstrating the effectiveness of the treatments. While a slight reduction of 8.31% is observed at 100% replacement (SMRCA 100), substantial strength gains of 1.68% and 20.40% are achieved at 75% and 50% replacement levels, respectively. Furthermore, SMRCA concrete exhibits reduced drying shrinkage (17-21%), increased electrical resistivity (34-42%), and enhanced resistance to chloride ion penetration (28-31%) at 100% replacement, indicating improved durability compared to conventional RCA.

Cancer is among the leading causes of mortality and morbidity globally. Natural products have played a significant role in bringing novel therapies to the clinic for the treatment of various types of cancer. However, several natural products have low potency, chemical instability, poor pharmacokinetics, and high toxicity. Therefore, a natural-product-inspired strategy has been utilized to overcome the limitations of natural products in cancer drug discovery. Herein, we present a critical review to describe how medicinal chemists designed anti-cancer agents via a natural-product-inspired strategy. We have also illustrated how this approach is used to overcome drug resistance in cancer. The natural product-inspired analogues/derivatives were classified into different categories. Our focus extends to reviewing the design strategies, in vitro/in vivo results, and structure-activity relationship (SAR) studies of natural-product-inspired molecules as anti-cancer agents. We expect that this review will inspire the development of more effective and diversified anti-cancer agents.

This study evaluates the potential of oil seed extract ashes (OSAs) from niger, cotton, and flaxseed, as a supplementary cementitious material (SCM) in cement mortar applications. The pozzolanic reactivity of niger and flaxseed OSAs was assessed through compressive strength tests, with results showing 28-day strengths of 40.74 MPa and 43.36 MPa, respectively, achieving 85-90% of OPC at 48.73 MPa. Workability tests revealed slight reductions in flow diameters for niger (115 mm) and flaxseed (110 mm) OSAs compared to OPC (118 mm), indicating denser particle packing. In contrast, cotton OSA exhibited a higher flow of 140 mm. Cotton OSA lacks pozzolanic activity compared to niger and flaxseed due to the absence of CaO and Al2O3, along with very low SiO2. Cost analysis demonstrated a 7.6-9.2% reduction in material costs, with niger-based mortar priced at INR 5504/m3 and flaxseed-based mortar at INR 5605/m3, compared to OPC at INR 6065/m3. CO2 emissions were reduced by 19%, with niger and flaxseed OSA mortars emitting 401 kg CO2/m3 and 400 kg CO2/m3, respectively, compared to 494 kg CO2/m3 for OPC. The microstructural characterization of these OSAs by FESEM, XRF, XRD, FTIR, Raman, and TGA confirms that these materials present viable, cost-effective, and eco-friendly alternatives to OPC as SCMs.

This study aims to assess the technical, environmental, and multi-criteria performance of fly ash (FA) modified self-compacting concrete (SCC) incorporating granite waste aggregate (GWA). Nine SCC mixtures were developed by replacing cement with a constant 30 % FA and natural fine aggregate (NFA) with varying GWA contents ranging from 0 % to 60 %. Technical properties such as compressive strength, water permeability, water absorption, sorptivity, and chloride ion diffusion were evaluated. Results showed an increase in compressive strength of around 20 % with up to 40 % GWA incorporation. Mixtures containing up to 50 % GWA exhibited reductions in water permeability, water absorption, sorptivity (i.e., capillary rise), and chloride ion penetration by around 53 %, 15 %, 24 %, and 25 %, respectively, compared to the FA modified control SCC mix. SEM analysis confirmed a denser microstructure in SCC containing up to 50 % GWA. The environmental performance of SCC incorporating FA and GWA was evaluated through life cycle assessment (LCA), which indicated significant reductions in environmental impacts, like, 26 % in global warming potential, 23 % in mineral resource scarcity, 25 % in fossil resource scarcity, and 11 % in ozone formation. Additionally, multi-criteria decision-making (MCDM) analysis using both TOPSIS and VIKOR methods identified 30-35 % GWA as the optimal dosage for SCC mixes. Overall, SCC mixtures incorporating 30 % GWA demonstrated the most balanced performance, making them ideal for use in densely reinforced structural elements due to their enhanced technical and environmental benefits.

Rheology, the study of flow and deformation in materials, is key to understanding the flow behavior of fresh cementitious materials, which, in turn, influences their hardened properties and durability. The rheology of cementitious mixes is complex and significantly impacts their fresh-state application in construction. Understanding and controlling the factors affecting rheology is crucial for optimizing mix designs and improving construction practices. This study provides an in-depth understanding of cementitious mix rheology, factors influencing rheology, optimization, and its correlation with mathematical models. The paper presents the impact of internal factors, such as water–cement ratio and cement fineness, as well as external factors, like temperature, shear rate, and time, on the rheology of cementitious materials. The study examines how these factors influence fundamental rheological characteristics and behaviors such as thixotropy and shear thinning. It outlines ways to optimize mix designs, enhance workability, and improve emerging technologies like 3D concrete printing. Additionally, it correlates available mathematical models with the identified influencing factors. This analysis fills a gap in existing literature and contributes to advancing concrete technology and its practical applications, paving the way for innovative solutions in the construction industry. It also provides directions for future research in rheological behavior modeling, potentially leading to more efficient and sustainable concrete construction practices.