Manganese Carbonate/Laser-Induced Graphene Composite for Glucose Sensing.

Laser-induced graphene (LIG) has received great interest as a potential candidate for electronic and sensing applications. In the present study, we report the enhanced performance of a manganese carbonate-decorated LIG (MnCO3/LIG) composite electrode material employed for electrochemical glucose detection. Initially, the porous LIG was fabricated by directly lasing poly(ether sulfone) membrane substrate. Then, the MnCO3/LIG composite was synthesized via a hydrothermal method. Later, MnCO3/LIG was immobilized onto a glassy carbon electrode surface and employed for glucose detection. The structure of the MnCO3/LIG composite was carefully characterized. The influence of the MnCO3/LIG composite on the performance of the electrode was investigated using cyclic voltammetry curves. The MnCO3/LIG composite exhibited an excellent sensitivity of 2731.2 µA mM-1 cm-2, and a limit of detection of 2.2 µM was obtained for the detection of glucose. Overall, the performance of the MnCO3/LIG composite was found to be superior to that of most of the MnCO3-based composites.

Potential of ionic liquids as emerging green solvent for the pretreatment of lignocellulosic biomass.

Lignocellulosic biomass is available in abundance as a renewable resource, but the major portion of it is often discarded as waste without utilizing its immense potential as an alternative renewable energy resource. To overcome recalcitrance of lignocellulosic biomass, various pretreatment methods are applied to it, so that the complex and rigid polymeric structure can be broken down into fractions susceptible for enzymatic hydrolysis. Effective and efficient biomass processing is the goal of pretreatment methods, but none of the explored pretreatment methods are versatile enough to fulfil the requirement of biomass processing with greater flexibility in terms of operational cost and desired output efficiency. Deployment of green solvents such as ionic liquids for the pretreatment of lignocellulosic biomass has been a topic of discussion amongst the scientific community in recent times. The presented work provides a detailed overview on the deployment of ionic liquid for the pretreatment of lignocellulosic biomass coupled with a brief discussion on other pretreatments methods. The recyclability and reusability along with other unique properties makes an ionic liquid pretreatment different from the other traditional pretreatment methods. Also, this study explores diverse critical parameters that governs the dissolution process of biomass. Hazardous properties of ionic liquids have also been explored. Future perspective and recommendations have been given for an efficient, effective, and eco-friendly deployment of ionic liquid in biomass pretreatment process.

Advances in phase change materials and nanomaterials for applications in thermal energy storage.

Phase-changing materials are nowadays getting global attention on account of their ability to store excess energy. Solar thermal energy can be stored in phase changing material (PCM) in the forms of latent and sensible heat. The stored energy can be suitably utilized for other applications such as space heating and cooling, water heating, and further industrial processing where low-temperature heat energy is required. The presented work attempts to evaluate past, present, and future trends in the development of energy storage materials and their encapsulation techniques for efficient utilization of the available energy. Hybrid PCM with nanoparticles has excellent potential to tailor thermo-physical properties and uplift the efficiency of energy storage systems. Synergistic use of PCM with nanomicromaterial can further improve the capacity of energy storage system along with the charging and discharging efficiencies of the system. Impacts of the size of particle, concentration ratio, and shape of particle have been studied to assess their effectiveness in enhancing storage efficiency of the systems. Waste heat recovered and stored in energy storage materials can undoubtedly improve the total energy availability of the source, thus enhancing the exergy efficiency with simultaneous reduction in the entropy generation rate. Core-shell nanoparticles can further improve the optical absorptance spectra towards an infrared region of thermal energy. Paraffin wax-based NEPCMs with graphene nanoplatelets achieve 2.14 W/(m·K) thermal conductivity, enabling faster and more efficient heat transmission and lowering charging and discharging times for thermal storage devices.

Oxyanion Removal from Impaired Water by Donnan Dialysis Plug Flow Contactors.

In the last twenty-five years, extensive work has been done on ion exchange membrane bioreactors (IEMB) combining Donnan dialysis and anaerobic reduction to remove trace oxyanions (e.g., perchlorate, nitrate, chlorate, arsenate) from contaminated water sources. Most studies used Donnan dialysis contactors with high recirculation rates on the feed side, so under continuous operation, the effective concentration on the feed side of the membrane is the same as the exit concentration (CSTR mode). We have built, characterized, and modelled a plug flow Donnan dialysis contactor (PFR) that maximizes concentration on the feed side and operated it on feed solutions spiked with perchlorate and nitrate ion using ACS and PCA-100 anion exchange membranes. At identical feed inlet concentrations with the ACS membrane, membrane area loading rates are three-fold greater, and fluxes are more than double in the PFR contactor than in the CSTR contactor. A model based on the nonlinear adsorption of perchlorate in ACS membrane correctly predicted the trace ion concentration as a function of space-time in experiments with ACS. For PCA membrane, a linear flux dependence on feed concentration correctly described trace ion feed concentration as a function of space-time. Anion permeability for PCA-100 was high enough that the overall mass transfer was affected by the film boundary layer resistance. These results provide a basis for efficiently scaling up Donnan dialysis contactors and incorporating them in full-scale IEMB setups.

A Rare Case of Persistent Left Superior Vena Cava Coexisting With Valvulopathies and Complete Heart Block.

Persistent left superior vena cava (PLSVC) is a rare congenital vascular anomaly that is often detected incidentally during cardiovascular imaging or interventions. Coexisting PLSVC with mitral regurgitation (MR), aortic stenosis (AS), aortic regurgitation (AR), and complete heart block (CHB) are exceptionally rare and have not been reported in the literature to our knowledge. We present the case of a 50-year-old male with PLSVC coexisting with severe MR, mild AS/AR, and CHB who successfully underwent permanent pacemaker (PPM) implantation and mitral valve replacement. Comprehensive diagnostic evaluation and tailored management strategies are crucial for achieving significant improvement in the patient's symptoms. The presence of PLSVC adds complexity to diagnosis and management, necessitating multidisciplinary collaboration for optimal patient care.

A critical review on sustainable hazardous waste management strategies: a step towards a circular economy.

Globally, industrialisation and urbanisation have led to the generation of hazardous waste (HW). Sustainable hazardous waste management (HWM) is the need of the hour for a safe, clean, and eco-friendly environment and public health. The prominent waste management strategies should be aligned with circular economic models considering the economy, environment, and efficiency. This review critically discusses HW generation and sustainable management with the strategies of prevention, reduction, recycling, waste-to-energy, advanced treatment technology, and proper disposal. In this regard, the major HW policies, legislations, and international conventions related to HWM are summarised. The global generation and composition of hazardous industrial, household, and e-waste are analysed, along with their environmental and health impacts. The paper critically discusses recently adapted management strategies, waste-to-energy conversion techniques, treatment technologies, and their suitability, advantages, and limitations. A roadmap for future research focused on the components of the circular economy model is proposed, and the waste management challenges are discussed. This review stems to give a holistic and broader picture of global waste generation (from many sources), its effects on public health and the environment, and the need for a sustainable HWM approach towards the circular economy. The in-depth analysis presented in this work will help build cost-effective and eco-sustainable HWM projects.

An experimental investigation on the effects of magnesia and alumina nano additives on the exhaust emissions and performance of CI engine using spirulina microalgae biodiesel.

The need for non-renewable fuels is steadily decreasing with their ever-increasing cost and air pollution. As a result, renewable fuel such as biofuel is used as a fuel substitute for diesel engines. The effects of magnesia and alumina nanoparticles on the exhaust pollutants and performance of a naturally aspirated, 17.5 compression ratio, 4-stroke CI engine operating on spirulina microalgae biodiesel, and its amalgams were explored. Oxides of nitrogen, thermal efficiency, carbon dioxide, fuel consumption, and hydrocarbons were among the attributes studied. Test outcomes revealed that the doping of magnesia and alumina nano additives in spirulina biodiesel resulted in increased thermal efficiency and oxides of nitrogen, succeeded by a decrease in fuel consumption and hydrocarbons, at all loads, compared to amalgams without nano additives. At maximum load, the increase in thermal efficiency and oxides of nitrogen was found to be 1.15 and 1.46% with nano magnesia-doped blends when compared to corresponding spirulina blends. On the other, hand when nano alumina is doped in spirulina amalgams, the increase in thermal efficiency and oxides of nitrogen was observed to be 0.82 and 0.97%, respectively. Similarly, fuel consumption and hydrocarbons were reduced by 1.02 and 9.52%, 1.014, and 7.66%%, respectively, for magnesia and alumina-enriched biodiesel, contrasted to that of biodiesel blends.

Particle preparation of pharmaceutical compounds using supercritical antisolvent process: current status and future perspectives.

The low aqueous solubility and subsequently slow dissolution rate, as well as the poor bioavailability of several active pharmaceutical ingredients (APIs), are major challenges in the pharmaceutical industry. In this review, the particle engineering approaches using supercritical carbon dioxide (SC CO2) as an antisolvent are critically reviewed. The different SC CO2-based antisolvent processes, such as the gas antisolvent process (GAS), supercritical antisolvent process (SAS), and a solution-enhanced dispersion system (SEDS), are described. The effect of process parameters such as temperature, pressure, solute concentration, nozzle diameter, SC CO2 flow rate, solvent type, and solution flow rate on the average particle size, particle size distribution, and particle morphology is discussed from the fundamental perspective of the SAS process. The applications of the SAS process in different formulation approaches such as solid dispersion, polymorphs, cocrystallization, inclusion complexation, and encapsulation to enhance the dissolution rate, solubility, and bioavailability are critically reviewed. This review highlights some areas where the SAS process has not been adequately explored yet. This review will be helpful to researchers working in this area or planning to explore SAS process to particle engineering approaches to tackle the challenge of low solubility and subsequently slow dissolution rate and poor bioavailability.

Liquid antisolvent crystallization of pharmaceutical compounds: current status and future perspectives.

The present work reviews the liquid antisolvent crystallization (LASC) to prepare the nanoparticle of pharmaceutical compounds to enhance their solubility, dissolution rate, and bioavailability. The application of ultrasound and additives is discussed to prepare the particles with narrow size distribution. The use of ionic liquid as an alternative to conventional organic solvent is presented. Herbal compounds, also known for low aqueous solubility and limited clinical application, have been crystalized by LASC and discussed here. The particle characteristics such as particle size and particle size distribution are interpreted in terms of supersaturation, nucleation, and growth phenomena. To overcome the disadvantage of batch crystallization, the scientific literature on continuous flow reactors is also reviewed. LASC in a microfluidic device is emerging as a promising technique. The different design of the microfluidic device and their application in LASC are discussed. The combination of the LASC technique with traditional techniques such as high-pressure homogenization and spray drying is presented. A comparison of product characteristics prepared by LASC and the supercritical CO2 antisolvent method is discussed to show that LASC is an attractive and inexpensive alternative for nanoparticle preparation. One of the major strengths of this paper is a discussion on less-explored applications of LASC in pharmaceutical research to attract the attention of future researchers.

Modelling and parameter optimisation for performance evaluation of sequencing batch reactor for treating hospital wastewater.

Hospital wastewater treatment is gaining attention in recent studies due to its complex nature. The performance of the sequencing batch reactor coupled with tube-settler was investigated for hospital wastewater treatment. The performance was evaluated regarding removing organic matter and nutrients (nitrate and phosphate). The phosphate was removed in the sequencing batch reactor and its associated tube-settler with a 60% removal efficiency margin. Nitrification was observed in sequencing batch reactor and tube-settler, but denitrification could not be achieved. The nitrification-denitrification process was not completed during the process. The current work's main aim was to understand and optimise the operational parameters involved in the performance of the sequencing batch reactor. The operational parameters were optimised using Design expert software, and Response Surface Methodology involved a four-factor and five-level central composite design. The percentage removal of chemical oxygen demand, nitrate, and phosphate was selected to be observed during this study. Supplementary Information: The online version contains supplementary material available at 10.1007/s13399-022-03406-z.

Highly Robust Laser-Induced Graphene (LIG) Ultrafiltration Membrane with a Stable Microporous Structure.

Laser-induced graphene (LIG) materials have great potential in water treatment applications. Herein, we report the fabrication of a mechanically robust electroconductive LIG membrane with tailored separation properties for ultrafiltration (UF) applications. These LIG membranes are facilely fabricated by directly lasing poly(ether sulfone) (PES) membrane support. Control PES membranes were fabricated through a nonsolvent-induced phase separation (NIPS) technique. A major finding was that when PES UF membranes were treated with glycerol, the membrane porous structure remained almost unchanged upon drying, which also assisted with protecting the membrane's nanoscale features after lasing. Compared to the control PES membrane, the membrane fabricated with 8% laser power on the bottom layer of PES (PES (B)-LIG-HP) demonstrated 4 times higher flux (865 LMH) and 90.9% bovine serum albumin (BSA) rejection. Moreover, LIG membranes were found to be highly hydrophilic and exhibited excellent mechanical and chemical stability. Owing to their excellent permeance and separation efficiency, these highly robust electroconductive LIG membranes have a great potential to be used for designing functional membranes.

Resistance to unfolding by acidic pH and resistance to lysosomal degradation explains disease-association of HLA-B27 subtypes.

Several hypotheses have been proposed to explain the high rate of disease association of HLA-B27 with ankylosing spondylitis (AS), including formation of disulfide-bonded dimers and misfolding of the heavy chain (HC), involving formation of high molecular weight (HMW) multimers. Recently, we have shown that the HMW entities of non-disease associated (non-DA) subtypes cause activation of endosomal-lysosomal pathways, while disease-associated (DA) subtypes of HLA-B27 cause activation of autophagy and unfolded protein response (UPR) pathways. In this paper, we seek an explanation for the failure of these pathways to degrade the HMW entities of DA subtypes of HLA-B27, using a combination of in vitro assays, using extracellular domains of heavy chains (EDHC), as well as in vivo assays, using stable transfectants of the full lengths of heavy chains (FLHC) of DA and non-DA subtypes. Our data shows that both DA and non-DA subtypes form HMW entities. However, non-DA HMW entities display far greater levels of degradation than DA HMW species. Non-DA EDHC display greater loss of structure at lysosomal pH in vitro. This was confirmed by experiments showing that (i) DA FLHCs co-localize with LAMP1, and (ii) induction of autophagy by rapamycin causes significant decrease in levels of non-DA HMW entities, but not that of DA HMW entities. These results point towards lack of facile lysosomal clearance of FLHCs of DA subtypes, suggesting that disease association of HLA-B27 subtypes is correlated with higher persistence of HMW entities in the low pH of lysosomes, with higher potential to trigger immune response.

Advancements in solar technologies for sustainable development of agricultural sector in India: a comprehensive review on challenges and opportunities.

Agriculture is the main occupation of the majority of people in India. The majority of the population in India is dependent (directly or indirectly) on agriculture as an occupation. The agriculture sector requires more freshwater and power for better yield in the current scenario. Nevertheless, the ever-increasing rate of energy consumption, limited fossil fuels, and rising pollution have made the expansion of renewable resources essential. Due to the suitable solar potential available in India, the deployment of solar energy has been more as compared to other renewable resources. The current study aims to discuss the various technologies, initiatives and policies of solar energy usage in agriculture. This work delivers an assessment of the advancement of solar energy vis-à-vis agricultural applications through the greenhouse concept and photovoltaic approach in India. Various agricultural applications of solar energy, such as solar water desalination system, solar water pumping system, solar crop dryer system for food safety, etc. are discussed as a means to promote solar-based technology. It also highlights the scenario of solar energy in India with important accomplishments, developmental approaches, and future potential. In-depth studies of various policies and government initiatives including those in research and development are also discussed. The current survey on solar technologies will be an aid to agribusiness frameworks to comprehend the statuses, obstructions, and extent of advancement. Finally, some future recommendations for further developments in this approach are discussed. This work sheds light on varied areas of solar energy-assisted agricultural systems as a potentially sustainable and eco-friendly pathway.

A critical review on the particle generation and other applications of rapid expansion of supercritical solution.

The novel particle generation processes of Active Pharmaceutical Ingredient (API)/drug have been extensively explored in recent decades due to their wide-range applications in the pharmaceutical industry. The Rapid Expansion of Supercritical Solutions (RESS) is one of the promising techniques to obtain the fine particles (micro to nano-size) of APIs with narrow particle size distribution (PSD). In RESS, supercritical carbon dioxide (SC CO2) and API are used as solvent and solute respectively. In this literature survey, the application of RESS in the formation of fine particles is critically reviewed. Solubility of API in SC CO2 and supersaturation are the key factors in tuning the particle size. The different approaches to model and predict the solubility of API in SC CO2 are discussed. Then, the effect of process parameters on mean particle size and the particle size distribution are interpreted in the context of solubility and supersaturation. Furthermore, the less-explored applications of RESS in preparation of solid-lipid nanoparticles, liposome, polymorphic conversion, cocrystallization and inclusion complexation are compared with traditional processes. The solubility enhancement of API in SC CO2 using co-solvent and its applications in particle generation are explored in published literature. The development and modifications in the conventional RESS process to overcome the limitations of RESS are presented. Finally, the perspective on RESS with special attention to its commercial operation is highlighted.

Electrochemical Removal of Organic and Inorganic Pollutants Using Robust Laser-Induced Graphene Membranes.

The removal of emerging environmental pollutants in water and wastewater is essential for high drinking water quality or for discharge to the environment. Electrochemical treatment is a promising technology shown to degrade undesirable organic compounds or metals via oxidation and reduction, and carbon-based electrodes have been reported. Here, we fabricated a robust, porous laser-induced graphene (LIG) electrode on a commercial water treatment membrane using the multilasing technique and demonstrated the electrochemical removal of iohexol, an iodine contrast compound, and chromium(VI), a highly toxic heavy metal ion. Multiple lasing resulted in a more ordered graphitic lattice, a more physically robust carbon layer, and a 3-4-fold higher electrical conductivity. These properties ultimately led to a more efficient electrochemical process, and the optimized LIG electrodes showed a higher hydrogen peroxide (H2O2) generation. At 3 V, 90% of Cr(VI) was removed after 6 h and reached >95% removal after 8 h at pH 2. Cr(VI) was mainly reduced to Cr(III), with small amounts of Cr(I) and Cr(0), which were partially deposited on the electrode membrane surface, confirmed with X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy analysis. Under the same conditions, 50% of iohexol was degraded after 6 h and the transformation products (TPs) were identified using ultra-performance liquid chromatography coupled with mass spectroscopy. A total of seven main intermediates were identified including deiodinated TPs (m/z = 695, 570, and 443), probably occurring via three transformation pathways including oxidative deiodination, amide hydrolysis, and deacetylation. The electrical energy costs calculated for the removal of 2 mg L-1 Cr(VI) was ∼$0.08/m3 in this system. Taken together, the porous LIG electrodes might be utilized for electrochemical removal of emerging contaminants in multiple applications because they can be rapidly formed on flexible polymer substrates at low cost.

Differences in Cellular Clearing Mechanisms of Aggregates of Two Subtypes of HLA-B27.

Ankylosing spondylitis (AS) belongs to a group of diseases, called spondyloarthropathies (SpA), that are strongly associated with the genetic marker HLA-B27. AS is characterized by inflammation of joints and primarily affects the spine. Over 160 subtypes of HLA-B27 are known, owing to high polymorphism. Some are strongly associated with disease (e.g., B*2704), whereas others are not (e.g., B*2709). Misfolding of HLA-B27 molecules [as dimers, or as high-molecular-weight (HMW) oligomers] is one of several hypotheses proposed to explain the link between HLA-B27 and AS. Our group has previously established the existence of HMW species of HLA-B27 in AS patients. Still, very little is known about the mechanisms underlying differences in pathogenic outcomes of different HLA-B27 subtypes. We conducted a proteomics-based evaluation of the differential disease association of HLA B*2704 and B*2709, using stable transfectants of genes encoding the two proteins. A clear difference was observed in protein clearance mechanisms: whereas unfolded protein response (UPR), autophagy, and aggresomes were involved in the degradation of B*2704, the endosome-lysosome machinery was primarily involved in B*2709 degradation. These differences offer insights into the differential disease association of B*2704 and B*2709.

Ion Transport in Laser-Induced Graphene Cation-Exchange Membrane Hybrids.

Ion-exchange membranes hybridized with laser-induced graphene (LIG) might lead to membranes with functional surface effects such as antifouling, antibacterial, or joule heating effects; however, understanding the change in the electrical properties of the membrane is essential. Here we studied LIG-modified ion-exchange polymeric membranes using electrochemical impedance spectroscopy (EIS). The conductivity of the anionic sulfonated poly(ether sulfone) membranes and the effective capacitance of the membrane-electrolyte interface were obtained by fitting the EIS spectra to an electrochemical equivalent circuit and compared with LIG-modified nonionic poly(ether sulfone) films. The transport selectivity (as the relative permeability) of counterions (K+, Na+, Mg2+, Ca2+) across the membrane was quantified using the membrane's conductivities obtained from the EIS measurements. The total ohmic resistance of the membrane was directly correlated to the polymer thickness (with negligible contribution from the conductive LIG layer), thereby establishing EIS as a rapid, low-cost, and noninvasive method to accurately probe substrate usage in LIG modification.

Silver-doped laser-induced graphene for potent surface antibacterial activity and anti-biofilm action.

Previously, laser-induced graphene (LIG) coated surfaces were shown to resist biofilm growth, although the material was not strongly antibacterial. Here, we show LIG surfaces doped with silver nanoparticles (Ag0 or AgNPs) as highly antibacterial surfaces. Starting from AgNO3 polyethersulfone (PES) polymer substrates, silver nanoparticles between 5-10 nm were generated in situ during the lasing process and stably embedded in the fibrous and porous structure of LIG in a single step. These silver doped LIG (Ag@LIG) surfaces were highly toxic to bacteria via a mechanism of both Ag+ ion release and possible surface toxicity of the AgNPs. The added antibacterial function of Ag-nanoparticles expands the functionality of LIG coated surfaces and might lead to highly effective point of use/entry devices in rural areas or in disaster situations with contaminated water sources.

Laser-Induced Graphene-PVA Composites as Robust Electrically Conductive Water Treatment Membranes.

Graphene nanomaterials can feature both superb electrical conductivity and unique physical properties such as extreme surface wettability, which are potentially applicable for many purposes including water treatment. Laser-induced graphene (LIG) is an electrically conductive three-dimensional porous carbon material prepared by direct laser writing on various polymers in ambient conditions with a CO2 laser. Low-fouling LIG coatings in water technology have been reported; however, the mechanical strength and the separation properties of LIG-coated membranes are limited. Here, we show mechanically robust electrically conductive LIG-poly(vinyl alcohol) (PVA) composite membranes with tailored separation properties suitable for ultrafiltration processes. PVA has outstanding chemical and physical stability with good film-forming properties and is a biocompatible and nontoxic polymer. Compared to LIG-coated filters, the PVA-LIG composite membrane filters exhibited up to 63% increased bovine serum albumin rejection and up to ∼99.9% bacterial rejection, which corresponded well to the measured molecular weight cutoff ∼90 kDa. Compared to LIG fabricated on a polymer membrane control, the composite membranes showed similar excellent antifouling properties including low protein adsorption, and the antibiofilm effects were more pronounced at lower PVA concentrations. Notably for the antibacterial capabilities, the LIG-supporting layer maintained its electrical conductivity and a selected LIG-PVA composite used as electrodes showed complete elimination of mixed bacterial culture viability and indicated that the potent antimicrobial killing effects were maintained in the composite. This work demonstrates that the use of LIG for practical industrial filtration applications is possible.