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Microbial Synthesis of Alkaloids and Applications in Healthcare
Plant alkaloids are a large group of natural compounds with wide-ranging bioactive characteristics, but the number of alkaloids obtained from the plant is low. Mass extraction of these bioactive alkaloids is affected by the trouble in large-scale propagation of these plants and absence of efficient strategies for extraction. However, production by chemical reactions is a substitute method; it is less effective due to its highly complex structure. The extensive study of alkaloid biosynthesis in plants and the advancement of genetic and metabolic engineering techniques enabled the opportunity to synthesise alkaloids through microbial hosts via metabolic engineering and bioprocess optimisations. In this chapter, we discuss the various gene-manipulation strategies to produce alkaloids in various microbial hosts and their application in the healthcare industry. 2023 selection and editorial matter, Ranjna Sirohi, Amit Kumar Rai, Luciana Porto de Souza Vandenberghe, and Binod Parameswaran; individual chapters, the contributors -
Microcannular electrode/polymer electrolyte interface for high performance supercapacitor
In the present work, the ionic resistance in the activated carbon (AC) electrode and blend polymer electrolyte (BPE) interface is reduced by tuning binder and BPE. A unique microcannulars channel connecting AC, binder and gaur gum (GG)/polyvinylalcohol (PVA) electrolyte is developed for easy Li+ movement. The use of AC derived from areca nut and natural GG as a binder makes the developed method more environmentally sustainable. The presence of microcannular structures on the electrode surface and BPE was confirmed using SEM and TEM analysis. Combined DSC-TGA data for BPE showed that PVA provides the mechanical support to jelly guar gum. The ionic conductivity, activation energy, dielectric studies were studied to understand the electrode/electrolyte interface mechanism. Dielectric studies revealed that the unique pathway of microcannular structures reduces the charge transfer resistance significantly at the interface. Optimized BPE was used in the fabrication of supercapacitor and specific capacitance was found to be 542 Fg-1. The time constant was 0.4 s and showed consistent cyclic pattern during galvanostatic charge/discharge studies with 99% Columbic efficiency. 2020 Elsevier Ltd -
Microencapsulated spirulina fortified yoghurt - An insight into physicochemical and sensory properties
Yoghurt is a widely consumed dairy product having good nutritional and functional properties. Incorporation of spirulina can enhance its health benefits due to its rich protein and antioxidant activity. However, direct addition affects sensory attributes, leading to reduced consumer acceptance. This study evaluates the impact of microencapsulated Spirulina-fortified yoghurt (ME-SP yoghurt) (treatment) on its physicochemical, microbiological and sensory properties, comparing it with plain yogurt as the negative control and Spirulina-incorporated yoghurt (without encapsulation) as the positive control. Results indicated that spirulina incorporation increased protein content in both positive control and treatment, but negatively influenced sensory acceptance in treatment due to colour and flavour changes. Microencapsulation effectively masked undesirable sensory characteristics while preserving nutritional benefits and an increase in protein content by 4.05%. More quantity of spirulina (1%) could be added to yoghurt when we used encapsulated spirulina than spirulina without encapsulation (0.5%). Textural analysis showed improved viscosity and stability in the microencapsulated sample than PC and NC. Microbiological analysis confirmed the probiotic viability in all samples within the acceptable range, based on the Food Safety and Standards Authority of India (FSSAI) and Codex Alimentarius standards for fermented dairy products. Sensory evaluation revealed that microencapsulation significantly enhanced flavour (7.9) compared to direct spirulina addition (6.96). This study concludes that microencapsulation is a viable technique to enhance the functional properties of spirulina-enriched yoghurt while maintaining its sensory appeal. 2025 Indian Council of Agricultural Research. -
Microfinance Sector and the Supportive Role of Regulator in its Transformation: A Case Study from India
Microfinance is a proven business model to deliver financial services to unbanked. In the beginning years of microfinance, Non-Governmental Organizations (NGOs) were engaged in microfinance initiative and used to raise capital through grants for their microfinance program, similar to other grant-based development initiatives. To become self-sustainable financial institutions, NGOs started to transform their microfinance initiatives to a for-profit legal entity. Microfinance experienced commercialization in the process of transformation which neglected the basics of microfinance, especially in protecting the interest of clients. Supportive role of regulator transformed the Indian microfinance sectors and formed sustainable financial institutions. The successful story of Reserve Bank of Indias (RBI) intervention in shaping Indian microfinance sector counters the argument of free market principle in fixing the interest rate and healthy regulation for microfinance institutions. Supportive role of Reserve Bank of India created win-win situation for both microfinance borrowers, microfinance institutions and other stakeholders for the long-term sustainability. The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021. -
Microgrid Energy Management- An Optimization Approach for Operational Cost Reduction
Optimization-based energy management and the related economic viability analysis of replacing a diesel generator alone-based microgrid with a PV, battery, fuel cell and diesel generator-based hybrid microgrid to minimize the operations cost, considering battery degradation and emissions, are presented in this work. The fuel cell considered here is the hydroplus fuel cell, which has minimum emissions, and eliminates the need for hydrogen storage. Mathematical modeling is based on experimentally obtained parameters for fuel consumption coefficients and emissions. The study considers an islanded mode of operation with two different scenarios of microgrid configuration, the first case with the hybrid microgrid working under optimal power conditions, and the second case with only diesel generator available to meet the load demand, for four representative months of the year. Comparing the operations cost under the two scenarios, replacement of a diesel generator-based microgrid, with a PV/battery/hydroplus fuel cell/diesel generator based microgrid resulted in reduction of daily operations cost by 54.06%, 35.25%, 34.38% and 32.71% for the months of January, April, July and October respectively. A sensitivity analysis with varied costs of fuel, operation and maintenance, and battery degradation proved that irrespective of these costs, a considerable amount of reduction in the operations cost is achieved. The results presented here are highly beneficial for application in microgrids worldwide. 2025 IEEE. -
Microhardness studies of GaTe whiskers
Single crystal whiskers of gallium telluride (GaTe) have been grown by the physical vapour deposition (PVD) method. Microindentation studies were carried out on the prism faces of the needles to understand their mechanical behaviour. The variation in the microhardnessof GaTe crystals with applied load has been determined at room temperature using Vickers microhardness indenter. The work- hardening exponent has also been computed for different load regions. 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. -
Microhardness studies of vapour grown tin (II) sulfide single crystals
Earth abundant tin sulfide (SnS) has attracted considerable attention as a possible absorber material for low-cost solar cells due to its favourable optoelectronic properties. Single crystals of SnS were grown by physical vapour deposition (PVD) technique. Microindentation studies were carried out on the cleaved surfaces of the crystals to understand their mechanical behaviour. Microhardness increased initially with the load, giving sharp maximum at 15 g. Quenching effect has increased the microhardness, while annealing reduced the microhardness of grown crystals. The hardness values of as-grown, annealed and quenched samples at 15 g load are computed to be 99.69, 44.52 and 106.29 kg/mm 2 respectively. The microhardness of PVD grown crystals are high compared to CdTe, a leading low-cost PV material. The as-grown faces are found to be fracture resistant. 2015 AIP Publishing LLC. -
Microindentation Analysis of Bi2Te3 Crystals
Recent trends and advancements in materials research and technology have led to a renewed interest in the growth of crystalline solids with better physical perfection and high purity. The major emphasis of investigations has been on the growth of single crystals and the study of their physical properties suitable for device fabrication. The availability of crystals from natural resources is inadequate to meet the need of industries and also do not give sufficient variety. Although crystal growth has been the subject of absorbing interest for many years, much of the latest developments have been stimulated due to its increasing commercial importance for the fabrication of thermoelectric, optoelectric and nonlinear optical devices. Crystal has an ordered arrangement of atoms or molecules in microscopic scale and the atomic regularity shows up in the internal and external symmetry. The change in crystal shape should be brought about by the difference in controlling mechanisms of the growth dynamics. It is inevitable to investigate the relationship between the growth mechanism and resulting growth morphology. The developments in crystal technology have significant contribution to many areas of basic and applied solid state research. Industries currently rely on bulk grown crystals of a variety of materials. Hence, single crystals have been extensively studied to explore their novel physical properties and potential applications. The first chapter deals with an introduction to the crystal growth, followed by a brief history of semiconducting materials. A detailed account on the properties and applications of bismuth telluride crystals is reported. This chapter concludes with different mechanical properties and scope of the research problem. A review of literature to present theoretical knowledge on growth and characterization of bismuth telluride crystals is given in chapter 2. Chapter 3 outlines the experimental procedures and different characterization techniques used for the present work. A detailed study on the vapour and melt growth of bismuth telluride crystals and its mechanical properties is also reported. Chapter 4 is devoted to provide a detailed discussion on the results obtained from experimental research. Final chapter covers the summary and conclusions of this research work. The report ends with a reference section, listed as per the international standards. -
Microlearning and Learning Performance in Higher Education: A Post-Test Control Group Study
This study aimed at evaluating the effectiveness of microlearning in higher education. The sample consisted of first-year MBA students, and a post-test control group design was used to assess the effectiveness of a microlearning module. The results indicated that the use of microlearning was significantly related to learning performance and participants' reactions to the module. Moreover, the microlearning group scored significantly higher than the control group. The findings suggest that microlearning has the potential to improve learning outcomes and enhance participant engagement. However, the study has certain limitations, and future research is needed to gain a comprehensive understanding of the optimal design and delivery of microlearning modules. The study supports the use of microlearning in higher education as an effective instructional strategy. 2024, Commonwealth of Learning. All rights reserved. -
Micromachining process-current situation and challenges
The rapid progress in the scientific innovations and the hunt for the renewable energy increases the urge for producing the bio electronic products, solar cells, bio batteries, nano robots, MEMS, blood less surgical tools which can be possible with the aid of the micromachining. This article helps us to understand the evolution and the challenges faced by the micromachining process. Micro machining is an enabling technology that facilitates component miniaturization and improved performance characteristics. Growing demand for less weight, high accuracy, high precision, meagre lead time, reduced batch size, less human interference are the key drivers for the micromachining than the conventional machining process. Owned by the authors, published by EDP Sciences, 2015. -
Microplastic pollution and its ecotoxicological impact: Evidence from Vembanad Lake and zebrafish studies
Microplastic (MP) contamination is a threat to Earth and its aquatic systems by destabilizing ecological equilibrium. This study examined the distribution and impact of MPs in Vembanad Lake, an urbanized estuarine system in Kerala, India. MPs were identified at every sampling location, while sites 2, 3, and 4 exhibited peak contamination levels of 79 MPs/L. A survey among local inhabitants reported a decline in fish populations over many years. Analytical characterization using SEM, EDS, FTIR, and Raman spectroscopy revealed the dominance of HDPE, LDPE, PS, PET, PP, and PVC polymers. The presence of chromium (Cr), sodium (Na), aluminum (Al), and silica (SiO?) in MPs further enhances additional toxicity risks. Zebrafish exposed to the prevalent MPs for 21 days exhibited severe epithelial necrosis alongside goblet cell hyperplasia and muscle fiber degeneration, demonstrating systemic cytotoxic effects. These findings underscore the ecological threat of MP pollution and emphasize the urgent need for mitigation strategies to protect aquatic biodiversity. 2025 Elsevier B.V. -
Microplastic residues in clinical samples: A retrospection on sources, entry routes, detection methods and human toxicity
Microplastics (MPs) are emerging toxicants which have been detected in varying environments. Despite MPs adverse effects, reports on MPs detection from human clinical samples are only a few. This is due to several reasons such as inefficiency of current MPs detection techniques to detect them from human clinical samples, lack of understanding about the MPs toxicity to human organs and ethical regulations that restricts study with human placental exposure to MPs. This review gives a comprehensive outlook on the major sources MPs sources and routes into human system and their human toxicity mechanisms. Further an in-depth discussion on the significance and limitations of various MPs detection methods is elaborated in the review. Challenges in current research framework for detection of MPs from human clinical samples and the possible future directions in this imperative research domain are also focused in this review. 2024 Elsevier B.V. -
Microplastics distribution and potential health implications of food and food products
Microplastics, miniscule plastic fragments ubiquitous in the environment, pose a growing threat as they infiltrate our food chain. This review delves into the contamination of various food categories, including seafood, agricultural products, and even processed foods through packaging and processing methods. Developing reliable analytical techniques to accurately detect microplastics levels within complex food matrices is crucial to gauge the true extent of this contamination. Although the entire range of potential health effects associated with microplastic intake is not yet known, there is reason to be concerned about the risks. These include the potential for microplastics to physically hurt the gastrointestinal tract, exposure to chemicals that seep from the polymers themselves, and the potential for microplastics to act as carriers for other dangerous compounds. This analysis identifies important knowledge gaps about the long-term health effects of microplastics exposure. It highlights the urgent need for more investigation to fully assess the possible dangers connected to microplastics in the food chain. Furthermore, it is imperative that efficient mitigation measures be put in place as soon as possible to protect food safety from microplastics contamination. More cooperation is required to create more stringent laws governing the use of plastic, investigate substitute materials for manufacturing and packaging, and create effective filtering systems for the processing of food and water. Through devoted research to close knowledge gaps and the implementation of strong mitigation strategies, can make proactive efforts to safeguard public health and maintain the integrity of our food supply chain for future generations. 2024 Elsevier Inc. -
Microplastics in food: Occurrence, toxicity, green analytical detection methods and future challenges
The pervasive presence of microplastics (MPs) in the environment has raised significant concerns about their infiltration into the human food chain. In current review, the occurrence and distribution of MPs in various food matrices such as seafood, drinking water, fruits, vegetables, and beverages are discussed along with their potential routes of MPs entry into the human food chain. The toxicity of MPs on human health and different organs are discussed in brief. Current technological advancement and green analytical methods for the detection of MPs in food samples are compared, discussing their advantages and limitations. Green analytical methods, including stereomicroscopy, Fourier Transform Infrared spectroscopy, Raman spectroscopy, and enzymatic digestion, are evaluated for their efficacy and environmental impact. The Analytical Eco-Scale is used to assess the greenness of these methods. Challenges associated with MPs detection in food, such as complex food matrices, pretreatment methods, and variability in MPs concentrations, are addressed. 2024 The Author(s) -
Micropollutants characteristics, fate, and sustainable removal technologies for landfill leachate: A technical perspective
Waste disposal in landfills has gained momentum in the last few decades as it is one among the easy and cost-effective method for waste management for the accelerating global population. Heterogenous nature of the waste ending up in landfills makes it difficult to predict the fate of these pollutants making it difficult for its biomonitoring and specific treatment. Among the major issues associated with landfill treatment, liquid percolation from this heterogenous waste substrate collectively referred as leachate poses the greater risk to environment through soil and ground water pollution. The diversity of micropollutants presents in landfill leachates ranging from microbial pathogens, pesticides, microplastics, pharmaceuticals and other harmful chemicals calls for crucial attention towards improving methods used for their treatment and removal. This review summarizes the key components of landfill leachates with specific emphasize on micropollutant content of leachate. Further the features of most recent and advanced technologies that were successfully explored for micropollutant removal from landfill leachates are presented in this review. 2023 Elsevier Ltd -
Microscale screen printing of large-area arrays of microparticles for the fabrication of photonic structures and for optical sorting
There are a limited number of methods applicable to the large-scale fabrication of arrays of discrete microparticles; however, such methods can be applied to the fabrication of structures applicable to photonics, barcoding, and optoelectronics. This manuscript describes a universal method, "microparticle screen printing" (?SP), for the rational patterning of micron-scale particles onto a variety of 2D substrates with diverse mechanical and chemical properties. Specifically, an array of microparticles of different sizes and compositions were patterned onto an array of materials of varying chemistry and stiffness using ?SP yielding a diversity of homo/heterogeneous microparticle-based structures. Further, this manuscript reports how the Young's moduli of the substrate can be used to calculate contact area and thus interaction energies (quantified using Hamaker constants) between the particle/substrate during ?SP. Generally, ?SP is most effective for substrates with low Young's moduli and large Hamaker constants (A132) with the target particles, as confirmed by the performance (quantified using yield and accuracy metrics) of ?SP for the different empirically investigated particle/substrate combinations. These understandings allow for the design of optimal surface/particle pairing for ?SP and were applied to the fabrication of a diversity of heterogeneous structures, including those with periodic vacancies in HCP (hexagonally closed packed) 2D photonic crystal useful to structural optics, optical particle screening useful to chemical assays, and the fabrication of structural barcodes useful for labeling and anticounterfeiting. 2018 The Royal Society of Chemistry. -
Microscopic, pharmacognostic and phytochemical screening of Epiphyllum oxypetalum (dc) haw leaves /
Journal of Pharmacognosy And Phytochemistry, Vol.7, Issue 6, pp.972-980, ISSN No: 2349-8234. -
Microstructural evolution and damping response in ARB-processed ZK60 alloy
This study investigates the effect of microstructural evolution on the damping behaviour of ZK60 magnesium alloy processed via Accumulative Roll Bonding (ARB). ARB was employed at 300C for up to four cycles, significantly refining the grain structure and altering dislocation and precipitation behaviour. Comprehensive microstructural analysis revealed the formation of fine equiaxed grains (?6.7 m), dissolution of coarse precipitates, and increased dislocation density. TEM and Selected Area Diffraction (SAD) patterns confirmed dynamic recrystallisation and uniform grain orientation, while XRD patterns exhibited peak broadening and intensity changes, indicating crystallite refinement and texture evolution. Damping results showed substantial improvements in the ARB-processed alloy, particularly at low-to-mid frequencies, with up to 21% higher damping capacity than the base alloy. This enhancement is attributed to increased grain boundary sliding, dislocation interactions, and refined precipitatematrix interfaces. Both alloys exhibited similar damping responses at higher frequencies, suggesting saturation of energy dissipation mechanisms. 2025 Canadian Institute of Mining, Metallurgy and Petroleum. -
Microstructural evolution and wear characteristics of equal channel angular pressing processed semi-solid-cast hypoeutectic aluminum alloys
This work investigated the microstructural evolution of Al-7Si-Mg alloy cast semi-solid using a cooling slope as well as conventional casting followed by equal channel angular pressing (ECAP) in a 120 die. Feed materials were prepared for ECAP by cooling slope casting and by conventional casting. The microstructure of the processed alloys extruded was observed by optical microscope and by transmission electron microscope, and their hardness and wear resistance were evaluated. After ECAP processing, the primary ?-Al phase tended to be elongated while the Si particles became fragmented and more nearly globular in shape and uniform in size than in the as-cast sample. The microstructure of the cooling slope-cast ECAPed samples was more homogenous than that of the conventionally cast ECAPed sample. The ?-Al phase sub-grains were refined to sub-micrometer sizes for samples cast by both methods after ECAP. The hardness of the cooling slope-cast ECAPed sample was also higher than that of the conventionally cast ECAPed sample. The wear resistance of the alloy improved after cooling slope casting and ECAP processing. 2014 The Authors. -
Microstructure and Mechanical Behaviour of Al6061-ZrB2 In-situ Metal Matrix Composites
Aluminium matrix composites processed through in-situ molten reaction has emerged as an alternative for eliminating defects existing in ex-situ reinforced metal matrix composites. Development of composites through in-situ method using inorganic salts via liquid metallurgy route is the most widely accepted technique. In the present work, Al6061-ZrB2 in-situ composites have been developed through in-situ reaction of Al-10%Zr and Al-3%B master alloys in Al6061 alloy. Study of microstructure and mechanical properties of in-situ reinforced ZrB2 in Al6061 alloy have been carried out. Composite exhibited grain refinement and improved the mechanical properties of Al6061 alloy. Ductility of composite is reduced with increase in content of ZrB2. Published under licence by IOP Publishing Ltd.