Sampled-data controller scheme for multi-agent systems and its Application to circuit network

The objective of this study is to investigate the synchronization criteria under the sampled-data control method for multi-agent systems (MASs) with state quantization and time-varying delay. Currently, a looped Lyapunov-Krasovskii Functional (LKF) has been developed, which integrates information from the sampling interval to ensure that the leader system synchronizes with the follower system, resulting in a specific condition in the form of Linear Matrix Inequalities (LMIs). The LMIs can be easily solved using the LMI Control toolbox in Matlab. Finally, the proposed approach's feasibility and effectiveness are demonstrated through numerical simulations and comparative results.

Development of Al-Mg2Si Alloy Hybrid Surface Composites by Friction Stir Processing: Mechanical, Wear, and Microstructure Evaluation

Surface composites are viable choices for various applications in the aerospace and automotive industries. Friction Stir Processing (FSP) is a promising method for fabricating surface composites. Aluminum Hybrid Surface Composites (AHSC) are fabricated using the FSP to strengthen a hybrid mixture prepared with equal parts of Boron carbide (B₄C), Silicon Carbide (SiC), and Calcium Carbonate (CaCO₃) particles. Different hybrid reinforcement weight percentages (reinforcement content of 5% (T1), 10% (T2), and 15% (T3)) were used in fabricating AHSC samples. Furthermore, different mechanical tests were performed on hybrid surface composite samples with different weight percentages of the reinforcements. Dry sliding wear assessments were performed in standard pin-on-disc apparatus as per ASTM G99 guidelines to estimate wear rates. The presence of reinforcement contents and dislocation behavior was investigated using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) studies. The results indicated that the Ultimate Tensile Strength (UTS) of sample T3 exhibited 62.63% and 15.17% higher than that of samples T1 and T2, respectively, while the Elongation (%) of T3 exhibited 38.46% and 15.38% lower than that of samples T1 and T2, respectively. Moreover, it was found that the hardness of sample T3 increased in the stir zone compared to samples T1 and T2, owing to its higher brittle response. The higher brittle response of sample T3 compared to samples T1 and T2 was confirmed by the higher value of Young's modulus and the lower value of Elongation (%).

Influence of Pore Size in Benzoin Condensation of Furfural Using Heterogenized Benzimidazole Organocatalysts

A designed N-heterocyclic carbene (NHC) catalyst was covalently anchored on a range of mesoporous and hierarchical supports, to study the influence of pore size in the benzoin condensation of furfural. The structural and spectroscopic characteristics of the anchored catalysts were investigated, also with the help of molecular dynamics simulations, in order to rationalize the degree of stability and recyclability of the heterogenized organocatalysts. Quantitative yields (99 %) and complete recyclability were maintained after several cycles, vindicating the design rationale.

Deciphering radiological stable disease to immune checkpoint inhibitors

BACKGROUND

'Stable disease (SD)' as per RECIST is a common but ambiguous outcome in patients receiving immune checkpoint inhibitors (ICIs). This study aimed to characterize SD and identify the subset of patients with SD who are benefiting from treatment. Understanding SD would facilitate drug development and improve precision in correlative research.

PATIENTS AND METHODS

A systematic review was carried out to characterize SD in ICI trials. SD and objective response were compared to proliferation index using The Cancer Genome Atlas gene expression data. To identify a subgroup of SD with outcomes mirroring responders, we examined a discovery cohort of non-small-cell lung cancer (NSCLC). Serial cutpoints of two variables, % best overall response and progression-free survival (PFS), were tested to define a subgroup of patients with SD with similar survival as responders. Results were then tested in external validation cohorts.

RESULTS

Among trials of ICIs (59 studies, 14 280 patients), SD ranged from 16% to 42% in different tumor types and was associated with disease-specific proliferation index (ρ = -0.75, P = 0.03), a proxy of tumor kinetics, rather than relative response to ICIs. In a discovery cohort of NSCLC [1220 patients, 313 (26%) with SD to ICIs], PFS ranged widely in SD (0.2-49 months, median 4.9 months). The subset with PFS >6 months and no tumor growth mirrored partial response (PR) minor (overall survival hazard ratio 1.0) and was proposed as the definition of SD responder. This definition was confirmed in two validation cohorts from trials of NSCLC treated with durvalumab and found to apply in tumor types treated with immunotherapy in which depth and duration of benefit were correlated.

CONCLUSIONS

RECIST-defined SD to immunotherapy is common, heterogeneous, and may largely reflect tumor growth rate rather than ICI response. In patients with NSCLC and SD to ICIs, PFS >6 months and no tumor growth may be considered 'SD responders'. This definition may improve the efficiency of and insight derivable from clinical and translational research.

over-activated p21 protein activated kinase-3 (pak3) leads to myocardial lipotoxicity and cardiac dysfunction in diet-induced metabolic stress

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation

Background

In clinics, metabolic stress-induced cardiomyopathy is featured as diastolic/systolic dysfunction, at least partially resulting from impairment of metabolic flexibility in the myocardium, which leads to lipotoxicity and oxidative stress accompanied with cardiomyocytes death. P21-activated kinases (Paks) are a family of serine/threonine kinases, involved in cell survival, proliferation and cytoskeleton remodelling. In spite of the cardioprotective functions of Pak1 and Pak2 in the myocardium, the role of cardiac Pak3 is unexplored.

Purpose

The study is to investigate the function of cardiac Pak3 on myocardial steatosis in response to diet-induced metabolic stress, which will provide proof-of-concept evidence for the therapeutic potential for alleviating cardiac dysfunction by targeting lipotoxicity in the myocardium.

Methods

Pak3 overexpression in the myocardium was achieved by tail vein injection of adeno associated virus (AAV9) delivery of troponin T promoter-driven Pak3 on C57BL/6J mice. The mice were fed with high fat high sucrose diet, the metabolic profiles and cardiac function were measured at 4-week intervals. In addition, cardiac morphological and cellular changes were assessed, including cell size, fibrosis formation, cell death, lipid accumulation and lipid peroxidation. In addition, the transcript levels of the genes either participating lipid metabolism or regulating oxidative stress were also assessed by qPCR.

Results

First, we detected that Pak3 expression and activation was increased in the myocardium from human with obese or diabetes. Consistently, the augmented Pak3 was also detected in the failing heart from C57BL/6J mice, ob/ob and db/db mice. Next, in a time-course study, the mice with AAV9-delivery cardiac Pak3 overexpression were vulnerable to cardiac dysfunction upon diet-induced metabolic stress. Pak3 overexpression did not alter cardiomyocyte size; however, more fibrosis and cell death in the myocardium were detected due to Pak3 enhancement. More importantly, myocardial lipid accumulation and profound lipid peroxidation were determined by immunefluorescent staining of Perilipin 5 (PLIN5) and 4-Hydroxynonenal (4-NHE), respectively. Finally, the abnormal expression of the genes involved in lipid synthesis and fatty acid oxidation was detected in Pak3-overexpressed myocardium under metabolic stress, whereas the levels of anti-oxidative stress genes were decreased.

Conclusion

Altogether, the study has demonstrated that Pak3 over-activation makes the heart more susceptible to myocardial lipotoxicity, which accelerates cardiac steatosis and dysfunction in the fact of metabolic stress.

EDEM2 regulation of cardiac lipid metabolism in heart failure with preserved ejection fraction

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation

Background

Heart failure with preserved ejection fraction (HFpEF) is the most predominant form of heart failure (HF) worldwide, one which confers substantial mortality and has no efficacious treatments. Lipid mishandling greatly contributes to the pathophysiology of HFpEF, nevertheless, the key mechanistic features regulating cardiac lipid overload remain poorly understood. EDEM2 plays a crucial role in the ER-associated degradation (ERAD) pathway. Recent studies show that ERAD-associated proteins are implicated in cellular lipid homeostasis, however, the role of EDEM2 is cardiac lipid metabolism remains poorly understood. Here, we investigate the mechanisms by which EDEM2 regulates cardiomyocyte lipid metabolism and cardiac dysfunction in HFpEF.

Methods

In vivo two-hit disease model of HFpEF, Adeno-associated virus serotype 9 (AAV9)-mediated cardiac-specific gene overexpression, tail-cuff blood pressure recordings, echocardiography, histology and qPCR.

Results

Under HFpEF inducing conditions, AAV9-Gfp injected mice (as controls) displayed an increased E/A ratio and IVRT both of which are indicative of diastolic dysfunction. Conversely, cardiac-specific EDEM2 overexpression prevented diastolic dysfunction in mice subjected to HFpEF conditions. Systolic function remained unchanged between groups. Interestingly, EDEM2 overexpression reduced myocardial neutral lipid accumulation and prevented severe oxidative stress and cardiac pathological remodeling. More importantly, although genes participating in fatty acid uptake and lipid droplets synthesis in the heart were comparable between AAV9-Gfp and AAV9-EDEM2 groups, those involved in lipolysis and fatty acid oxidation were upregulated in mice with cardiac-specific EDEM2 overexpression.

Conclusion

Cardiomyocyte-specific EDEM2 overexpression mitigates myocardial steatosis in a two-hit murine model of HFpEF, likely through enhancing fatty acid utilisation in the myocardium.

Paracrine signal emanating from stressed cardiomyocytes aggravates inflammatory microenvironment in diabetic cardiomyopathy

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation

Background

Cardiovascular issues associated with diabetes, such as diabetic cardiomyopathy (DCM), can lead to heart failure. DCM is etiologically related to myocardial inflammation and can stem from a complex interplay of different cell types. Cardiomyocyte as an active mediator of the inflammatory response is an emerging concept with limited mechanistic understanding.

Purpose

We aimed to address the knowledge gap of cardiomyocyte endoplasmic reticulum (ER) dysfunction-mediated macrophage response and provide functional evidence for the therapeutic feasibility of managing inflammatory paracrine signals in response to diet-induced metabolic stress.

Methods

In vivo mouse model of high fat high sucrose diet-induced diabetes, cardiomyocyte-specific p21-activated kinase 2 (PAK2) knockout model, echocardiography, histology, 3D imaging, qPCR, co-culture of H9c2 culturing medium and bone-marrow derived macrophages, immunoblotting, macrophage isolation from myocardium, flow cytometry and AAV9-gene therapy.

Results

In a time-course study, diet-induced diabetic mice demonstrated an association between cardiac ER stress and sustained myocardial inflammation, with a maladaptive shift in myocardial ER stress response over time. Furthermore, as a cardiac ER dysfunction model, mice with cardiac-specific PAK2 deletion exhibited heightened myocardial inflammatory response in diabetes. Using human and mice diabetic heart samples, we show that ER stress-induced CCAAT/enhancer-binding protein homologous protein (CHOP) is a novel transcriptional regulator of high mobility group box-1 (HMGB1). Cardiac stress-induced active release of HMGB1 facilitated M1 macrophage polarization, and aggravated myocardial inflammatory signatures. Therapeutically, sequestering the extracellular HMGB1 using Glycyrrhizin conferred cardioprotection through its anti-inflammatory action. Also, as functional evidence, we showed that un-mitigated cardiac ER response due to PAK2 loss under diabetes may account as a barrier for leveraging the anti-inflammatory potential of Vildagliptin.

Conclusion

Collectively, we introduce an ER stress-mediated cardiomyocyte-macrophage link, altering the macrophage response in the myocardium, thereby providing insight into therapeutic prospects for diabetes-associated cardiac dysfunction.

Combined spectroscopic and computational study for optimising catalyst design in hydrocarbon transformations

Molecular interactions of hydrocarbons within the confined pores of heterogeneous catalysts can influence reaction pathways, which play a crucial role in determining the overall efficacy of catalytic transformations. We probe...

Loose glass tesserae and lost decorations: chronology and production of mosaics from Gerasa's Northwest Quarter

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses of loose glass tesserae from the Northwest Quarter of Gerasa/Jerash has enhanced our understanding of the dynamics regulating the production and circulation of glass tesserae in second- to eighth-centuries ce Jordan and the diachronic development of mosaics at the site. The identification of Levantine and Egyptian compositions (Roman-Mn, Levantine I, HIMT, Foy 2.1) proves the continuous production of mosaics from the second to the seventh centuries. The Levantine I tesserae were made by the recycling and colouring of glass cullet. The gilded tesserae, in contrast, were all of an Egyptian base glass, likely illustrating the import of finished tesserae.

Thiol Functionalised Supports for Controlled Metal Nanoparticle Formation for Improved C-C Coupling

The myriad applications of metal nanoparticle systems have individual demands on their size, shape and electronic states, demanding novel synthetic methods to optimise these properties. Herein we report our method of exploiting strong thiol-Pd binding as a precursor for forming small, uniform Pd nanoparticles on activation. We validate our approach with a range of characterisation techniques and contrast our design strategy with an analogous wetness impregnation method, showing the drastic improvements for catalytic C-C coupling. The presence of the thiol groups offers greater control over nanoparticle formation, particularly temperature resolution on activation, potentially allowing more targeted nanoparticle formation procedures.

Understanding catalytic CO2 and CO conversion into methanol using computational fluid dynamics

The kinetics of methanol synthesis from a mixture of CO2/CO/H2 have been widely studied in the literature. Yet the role of direct CO hydrogenation is still unclear, in terms of predicting and developing an accurate kinetic model. To investigate, a computational fluid dynamics model has been developed, incorporating two distinct kinetic models, one which includes CO hydrogenation and one which does not. Including CO hydrogenation in the kinetic model provides a more complex interaction between the three involved reactions and can better predict potential inhibitions caused by the presence of H2O. This, however, increases the complexity of the kinetic model. The benefit of applying a fluid dynamics model to study fixed bed reactors is demonstrated, as it offers unique insights into the spatial species concentration, temperature variations, and reaction rate magnitudes. The validated model is shown to be a powerful interrogative tool, capable of supporting system optimization across the catalyst and reactor engineering sectors.

Rational Design and Application of Covalent Organic Frameworks for Solar Fuel Production

Harnessing solar energy and converting it into renewable fuels by chemical processes, such as water splitting and carbon dioxide (CO2) reduction, is a highly promising yet challenging strategy to mitigate the effects arising from the global energy crisis and serious environmental concerns. In recent years, covalent organic framework (COF)-based materials have gained substantial research interest because of their diversified architecture, tunable composition, large surface area, and high thermal and chemical stability. Their tunable band structure and significant light absorption with higher charge separation efficiency of photoinduced carriers make them suitable candidates for photocatalytic applications in hydrogen (H2) generation, CO2 conversion, and various organic transformation reactions. In this article, we describe the recent progress in the topology design and synthesis method of COF-based nanomaterials by elucidating the structure-property correlations for photocatalytic hydrogen generation and CO2 reduction applications. The effect of using various kinds of 2D and 3D COFs and strategies to control the morphology and enhance the photocatalytic activity is also summarized. Finally, the key challenges and perspectives in the field are highlighted for the future development of highly efficient COF-based photocatalysts.

Bimetallic PdAu Catalysts within Hierarchically Porous Architectures for Aerobic Oxidation of Benzyl Alcohol

Hierarchically porous (HP) zeotype materials (possessing both micropores and mesopores) offer improved diffusional access to intra-framework active sites, analogous to mesoporous materials, yet retain the high selectivity of the microporous (MP) bulk. We have recently designed crystalline hierarchically porous silicoaluminophosphates (SAPOs) with enhanced mass-transport characteristics, which can lead to significant improvement in catalytic activity and catalyst lifetime. In this study, we have prepared PdAu bimetallic nanostructures supported on HP-SAPO frameworks by an incipient impregnation of metal precursors followed by H₂ reduction at 300 °C, for the aerobic oxidation of benzyl alcohol to benzaldehyde. PdAu NPs supported on HP framework displayed significantly enhanced catalytic activities, when compared with their MP analogues, clearly highlighting the benefits of introducing hierarchical porosity in the SAPO support matrix.

Effectiveness of Short Form-36 Health Status Questionnaire Versus WOMAC Arthritis Index Questionnaire on Chronic Knee Osteoarthritis Patients

Introduction: Osteoarthritis is a common disease of aged population and one of the leading causes of disability. Key causes include obesity or overweight along with aging. Knee osteoarthritis can cause significant pain and functional loss. As the disease progresses, it can cause chronic knee joint pain, muscle weakness, joint deformity and functional deficiency which leads to decreased quality of life. The Western Ontario and McMaster Universities Osteoarthritis (WOMAC) is a 24-item questionnaire with 3 sub-scales measuring pain (5 items), stiffness (2 items) and physical function (17 items). Health related quality of life is measured using Short Form-36, used to examine health status in following eight domains: Bodily pain, physical function, role limitations due to social problems, physical problems, general health, vitality, social function, mental health, role limitation due to physical problems. Aim: To find the effect of Short Form-36 Health Status Questionnaire versus WOMAC Arthritis Index Questionnaire to measure the pain, Range of Motion (ROM) and disability in subjects with chronic knee osteoarthritis patients treated with Contrast Bath and Knee Exercises. Materials and Methods: This study was a pre and post longitudinal cohort study. A total of 90 patients were divided into two groups of 45 each. Each patient was given treatment for four weeks. Each patient was treated with Contrast bath and Knee Exercises. Group A patients were instructed to fill the Short Form-36 Health Status Questionnaire and Group B patients were instructed to fill the WOMAC Arthritis Index Questionnaire and outcome measures were collected on day 1, at the end of 2nd week and at the end of 4th week. Data from study were analysed using the statistical package SPSS 19.0 (SPSS Inc., Chicago, IL) and level of significance was set at p<0.05. Results: Group B shows a mean of the total score of WOMAC Arthritis Index Questionnaire which was 74.66 (SD 10.01) on Day 1; mean of 49.02 (SD 12.08) at the end of the 2nd week and a mean of 20.68 (SD 12.23) at the end of 4th week. The p-value was found to be 0.0001. The percentage disability evaluated by the WOMAC Arthritis Index Questionnaire shows a mean of 78 (SD 10) on Day 1; mean of 51 (SD 12) at the end of 2nd week and a mean of 22 (SD 13) at the end of 4th week. On day 1 Short Form-36 Questionnaire, total score of group A was 88.24 (SD 6.72) and at the end of 2nd week and 4th week the mean score was 94.06 (SD 5.10) and 98.72 (SD 4.55), respectively with statistically significant difference p-value (0.0001). Conclusion: The present study showed that the WOMAC Arthritis Index Questionnaire had superior sensitivity in reducing pain and increasing range of motion and thus by decreasing the disability.

The Significance of Metal Coordination in Imidazole-Functionalized Metal-Organic Frameworks for Carbon Dioxide Utilization

The grafting of imidazole species onto coordinatively unsaturated sites within metal-organic framework MIL-101(Cr) enables enhanced CO₂ capture in close proximity to catalytic sites. The subsequent combination of CO₂ and epoxide binding sites, as shown through theoretical findings, significantly improves the rate of cyclic carbonate formation, producing a highly active CO₂ utilization catalyst. An array of spectroscopic investigations, in combination with theoretical calculations reveal the nature of the active sites and associated catalytic mechanism which validates the careful design of the hybrid MIL-101(Cr).

Probing the Design Rationale of a High-Performing Faujasitic Zeotype Engineered to have Hierarchical Porosity and Moderated Acidity

Porosity and acidity are influential properties in the rational design of solid-acid catalysts. Probing the physicochemical characteristics of an acidic zeotype framework at the molecular level can provide valuable insights in understanding intrinsic reaction pathways, for affording structure-activity relationships. Herein, we employ a variety of probe-based techniques (including positron annihilation lifetime spectroscopy (PALS), FTIR and solid-state NMR spectroscopy) to demonstrate how a hierarchical design strategy for a faujasitic (FAU) zeotype (synthesized for the first time, via a soft-templating approach, with high phase-purity) can be used to simultaneously modify the porosity and modulate the acidity for an industrially significant catalytic process (Beckmann rearrangement). Detailed characterization of hierarchically porous (HP) SAPO-37 reveals enhanced mass-transport characteristics and moderated acidity, which leads to superior catalytic performance and increased resistance to deactivation by coking, compared to its microporous counterpart, further vindicating the interplay between porosity and moderated acidity.

Exploring the origins of crystallisation kinetics in hierarchical materials using in situ X-ray diffraction and pair distribution function analysis

The discovery of novel catalytic materials is predicated on understanding contemporary synthetic processes. With this fundamental knowledge in place it becomes possible to modify the final material with subtle changes to the synthesis process. In this vein, hierarchical materials, formed by the addition of a mesoporogen within the hydrothermal synthesis, have attracted a significant amount of attention due to their catalytic benefits over analogous microporous species. In this work we monitor the hydrothermal synthesis in situ of a hierarchical and a microporous aluminophosphate, for the first time, combining total scattering and pairwise distribution function data. In doing so we observe the local formation of the species, and the longer range crystallisation processes concurrently.

Functionalized mesoporous SBA-15 silica: recent trends and catalytic applications

The development of advanced materials for heterogeneous catalytic applications requires fine control over the synthesis and structural parameters of the active site. Mesoporous silica materials have attracted increasing attention to be considered as an important class of nanostructured support materials in heterogeneous catalysis. Their large surface area, well-defined porous architecture and ability to incorporate metal atoms within the mesopores lead them to be a promising support material for designing a variety of different catalysts. In particular, SBA-15 mesoporous silica has its broad applicability in catalysis because of its comparatively thicker walls leading to higher thermal and mechanical stability. In this review article, various strategies to functionalize SBA-15 mesoporous silica have been reviewed with a view to evaluating its efficacy in different catalytic transformation reactions. Special attention has been given to the molecular engineering of the silica surface, within the framework and within the hexagonal mesoporous channels for anchoring metal oxides, single-site species and metal nanoparticles (NPs) serving as catalytically active sites.

Designing Multi-Dopant Species in Microporous Architectures to Probe Reaction Pathways in Solid-Acid Catalysis

The introduction of two distinct dopants in a microporous zeotype framework can lead to the formation of isolated, or complementary catalytically active sites. Careful selection of dopants and framework topology can facilitate enhancements in catalysts efficiency in a range of reaction pathways, leading to the use of sustainable precursors (bioethanol) for plastic production. In this work we describe our unique synthetic design procedure for creating a multi-dopant solid-acid catalyst (MgSiAPO-34), designed to improve and contrast with the performance of SiAPO-34 (mono-dopant analog), for the dehydration of ethanol to ethylene. We employ a range of characterization techniques to explore the influence of magnesium substitution, with specific attention to the acidity of the framework. Through a combined catalysis, kinetic analysis and computational fluid dynamics (CFD) study we explore the reaction pathway of the system, with emphasis on the improvements facilitated by the multi-dopant MgSiAPO-34 species. The experimental data supports the validation of the CFD results across a range of operating conditions; both of which supports our hypothesis that the presence of the multi-dopant solid acid centers enhances the catalytic performance. Furthermore, the development of a robust computational model, capable of exploring chemical catalytic flows within a reactor system, affords further avenues for enhancing reactor engineering and process optimisation, toward improved ethylene yields, under mild conditions.

Cobalt-containing zeolitic imidazole frameworks for C–H activation using visible-light redox photocatalysis

Rationalising the photocatalytic activity of different cobalt ZIFs, provides an improved understanding of photocatalytic C–H activation.

Hybrid catalysts based on N-heterocyclic carbene anchored on hierarchical zeolites

Hybrid materials have been synthesized by anchoring a N-heterocyclic carbene (NHC) precursor on different inorganic zeolitic supports with hierarchical porosity, in particular hierarchical HZSM-5 and SAPO-5. Hierarchical porous inorganic supports have been obtained both by top-down and bottom-up approaches and the role of hierarchical porosity has been evaluated. A detailed physico-chemical characterization has been performed on the organic–inorganic hybrids using a multi-technique approach (XRD, volumetric and thermogravimetric analysis, ssNMR and FTIR) in order to establish a structure–property relationship. The hybrids were tested in the benzoin condensation reaction of furfural, a base catalyzed reaction.

N-heterocyclic carbene has been grafted on hierarchical HZSM-5 and SAPO-5 to obtain hybrid catalysts, that are active in the benzoin condensation reaction.

The influence of porosity on nanoparticle formation in hierarchical aluminophosphates

In this work we explore the deposition of gold onto a silicoaluminophosphate, using a variety of known nanoparticle deposition techniques. By comparing the gold particles deposited on a traditional microporous aluminophosphate, with an analogous hierarchical species, containing both micropores and mesopores, we explore the influence of this dual porosity on nanoparticle deposition. We show that the presence of mesopores has limited influence on the nanoparticle properties, but allows the system to maintain porosity after nanoparticle deposition. This will aid diffusion of reagents through the system, allowing continued access to the active sites in hierarchical systems, which offers significant potential in catalytic oxidation/reduction reactions.

Inter-relationship between intercepted radiation and rice yield influenced by transplanting time, method, and variety

Photosynthetically active radiation (PAR) is one of the most important environmental factors that determine the productivity and grain quality of the crops. Continuous rainy days or cloudy weather throughout crop growth especially at critical stages often resulted in great loss of grain quality and yield in rice. Low light stress has rigorously constrained the rice production in various rice-growing regions, especially in Southeast Asia. Method and time of planting are the major management factors contributing to the higher yield potential of rice by influencing light harvesting and use efficiency. Present study was executed consecutively for 5 years (kharif seasons of 2012-2016) to determine whether planting time improves the radiation absorption and use efficiency in different duration rice cultivars. We evaluated the difference in plant growth and development leading to yield formation under different planting time which related to radiation incidence and interception. The results of the study revealed that PAR interception depends on morphological characters of cultivars and also with agronomic management such as transplanting time and method. Long duration cultivar intercepted more PAR but interception decreased due to late planting (3rd week of July), whereas short duration cultivars (Naveen) when planted earlier (1st week of June) could not effectively utilize intercepted PAR constraining the biomass accumulation and yield formation. Effect of planting density and crop architecture on PAR absorption was apparent among establishment methods as light interception at crop canopy was highest in the system of rice intensification and lowest in that of wet direct seeding. In general, Pooja as a long duration cultivar intercepted more PAR per day but when compared on same date of planting, the comparative absorption of radiation was 30.6% higher in Naveen. The lower yields in the wet season are attributed mostly to reduction in grain number per panicle or per unit land area, which is a consequence of high spikelet sterility. Grain yield of rice planted in July third week was reduced by 3.8, 12.3, and 6.9% over June first and third week and July first week, respectively, mainly due to spikelet sterility (26%) and lower grains per panicle (18%). Our results indicated that agronomic management like optimum time of sowing, cultivar duration, and establishment methods should be followed for yield improvement in tropical lowlands where light intensity is limiting due to prevailing weather situations.

Waste not, want not: CO2 (re)cycling into block polymers

A new way to combine two different polymerisation reactions, using a single catalyst, results in efficient block polymer synthesis. The selective polymerisation of mixtures of l-lactide-O-carboxyanhydride and cyclohexene oxide, using a di-zinc catalyst in a one-pot procedure, allows the preparation of poly(l-lactide-b-cyclohexene carbonate). The catalysis near quantitatively recycles the carbon dioxide released during polyester formation into the subsequent polycarbonate block, with an atom economy of up to of 91%.

Correction: Waste not, want not: CO2 (re)cycling into block polymers

Correction for ‘Waste not, want not: CO₂ (re)cycling into block polymers’ by Sumesh K. Raman et al., Chem. Commun., 2019, 55, 7315–7318.

Acid properties of organosiliceous hybrid materials based on pendant (fluoro)aryl-sulfonic groups through a spectroscopic study with probe molecules

Hybrid heterogeneous catalysts containing (fluoro)aryl-sulfonic groups were characterized through combined spectroscopic techniques and adsorption of probe molecules, with their reactivity being modulated for acetal formation.

Comprehensive Vibrational Spectroscopic Characterization of Nylon-6 Precursors for Precise Tracking of the Beckmann Rearrangement

As a key step in nylon-6 synthesis, the Beckmann rearrangement is an ongoing target of catalytic studies that seek to improve the sustainability of polymer manufacture. Whilst solid-acid catalysts (predominantly zeotypes) have proven effective for this transformation, the development of more active and selective systems demands an understanding of fundamental catalytic mechanisms. In this undertaking, in situ and operando characterization techniques can be informative, provided rigorous spectroscopic groundwork is in place. Thus, to facilitate mechanistic studies we present a detailed investigation of the vibrational spectra of cyclohexanone, cyclohexanone oxime, ϵ-caprolactam and their D10-isotopomers, in the solid state. Variable-temperature infrared (150-300 K) and Raman (10-300 K) spectra are reported alongside inelastic neutron scattering data. Moreover, where key vibrational modes have been assigned with the aid of periodic density functional theory calculations, it has been possible to include hydrogen-bonding interactions explicitly.

8,9-Dimethoxybenzo[b]naphtho[2,3-d]thiophene

In the title compound, C18H14O2S, the system of four fused rings is almost planar (r.m.s. deviation = 0.022 Å). The C atoms of the methoxy groups deviate from the mean plane of the ring system by 0.373 (2) and −0.104 (2) Å. In the crystal, very weak aromatic π–π stacking interactions [shortest centroid–centroid separation = 3.9286 (10) Å] may help to establish the packing.

Chloridobis(ethane-1,2-diamine-κ2 N,N′)(3-methylpyridine-κN)cobalt(III) dichloride monohydrate

In the title hydrated salt, [CoCl(C6H7N)(C2H8N2)2]Cl2·H2O, the CoIII ion exhibits a distorted octahedral coordination envirnoment defined by four N atoms of two ethane-1,2-diamine ligands, another N atom of the pyridine ligand and a Cl− ligand. The pyridine N atom and the Cl− ligand are in cis positions relative to each other. The crystal packing is dominated by intermolecular N—H...Cl, O—H...Cl and O—H...H hydrogen-bonding interactions involving the amino groups of the complex cation, the lattice water molecule and the non-coordinating Cl− anions. Weak C—H...Cl interactions consolidate the three-dimensional hydrogen-bonded network structure.

Hierarchical SAPO-34 Architectures with Tailored Acid Sites using Sustainable Sugar Templates

In a distinct, bottom-up synthetic methodology, monosaccharides (fructose and glucose) and disaccharides (sucrose) have been used as mesoporogens to template hierarchical SAPO-34 catalysts. Detailed materials characterization, which includes solid-state magic angle spinning NMR and probe-based FTIR, reveals that, although the mesopore dimensions are modified by the identity of the sugar template, the desirable acid characteristics of the microporous framework are retained. When the activity of the hierarchical SAPO-34 catalysts was evaluated in the industrially relevant Beckmann rearrangement, under liquid-phase conditions, the enhanced mass-transport properties of sucrose-templated hierarchical SAPO-34 were found to deliver a superior yield of ϵ-caprolactam.

Approximation of state variables for discrete-time stochastic genetic regulatory networks with leakage, distributed, and probabilistic measurement delays: a robust stability problem

This work predominantly labels the problem of approximation of state variables for discrete-time stochastic genetic regulatory networks with leakage, distributed, and probabilistic measurement delays. Here we design a linear estimator in such a way that the absorption of mRNA and protein can be approximated via known measurement outputs. By utilizing a Lyapunov-Krasovskii functional and some stochastic analysis execution, we obtain the stability formula of the estimation error systems in the structure of linear matrix inequalities under which the estimation error dynamics is robustly exponentially stable. Further, the obtained conditions (in the form of LMIs) can be effortlessly solved by some available software packages. Moreover, the specific expression of the desired estimator is also shown in the main section. Finally, two mathematical illustrative examples are accorded to show the advantage of the proposed conceptual results.

Global exponential stability of Markovian jumping stochastic impulsive uncertain BAM neural networks with leakage, mixed time delays, and α-inverse Hölder activation functions

This paper concerns the problem of enhanced results on robust finite time passivity for uncertain discrete time Markovian jumping BAM delayed neural networks with leakage delay. By implementing a proper Lyapunov-Krasovskii functional candidate, reciprocally convex combination method, and linear matrix inequality technique, we derive several sufficient conditions for varying the passivity of discrete time BAM neural networks. Further, some sufficient conditions for finite time boundedness and passivity for uncertainties are proposed by employing zero inequalities. Finally, the enhancement of the feasible region of the proposed criteria is shown via numerical examples with simulation to illustrate the applicability and usefulness of the proposed method.